[PATCH 00/10] Start documenting the radeon drm better

[PATCH 00/10] Start documenting the radeon drm better

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

This is something I've been wanting to do for a while and
I finally spent a little time getting a start on it.  There
is still a lot to do and not all of my descriptions are great,
but I think we can document the rest in bits and pieces. I
also added a note about what asics the function is applicable
to. I tried to start with the more common and complex code.
I was thinking it would make sense to have an informal
documentation policy something like the following:
1. If you edit an undocumented function, add documentation
2. If you edit a documented function and change how it works,
   update the documentation
3. All new functions added should be documented

Fulfulling all of these for stable fixes could pose problems
so obviously there is some leeway.

Thoughts?

Alex Deucher (10):
  drm/radeon: document radeon_device.c
  drm/radeon: document radeon_kms.c
  drm/radeon: document radeon_irq_kms.c
  drm/radeon: document radeon_asic.c
  drm/radeon: document radeon_fence.c
  drm/radeon: document radeon_ring.c
  drm/radeon: document non-VM functions in radeon_gart.c
  drm/radeon: document VM functions in radeon_gart.c
  drm/radeon: start to document the functions r100.c
  drm/radeon: start to document evergreen.c

 drivers/gpu/drm/radeon/evergreen.c      |  120 ++++++++++
 drivers/gpu/drm/radeon/r100.c           |  127 ++++++++++-
 drivers/gpu/drm/radeon/radeon_asic.c    |   46 ++++
 drivers/gpu/drm/radeon/radeon_device.c  |  344 +++++++++++++++++++++++++++-
 drivers/gpu/drm/radeon/radeon_fence.c   |  373 +++++++++++++++++++++++++++++
 drivers/gpu/drm/radeon/radeon_gart.c    |  391 ++++++++++++++++++++++++++++++-
 drivers/gpu/drm/radeon/radeon_irq_kms.c |  150 ++++++++++++
 drivers/gpu/drm/radeon/radeon_kms.c     |  126 ++++++++++
 drivers/gpu/drm/radeon/radeon_ring.c    |  374 +++++++++++++++++++++++++++++-
 9 files changed, 2041 insertions(+), 10 deletions(-)

-- 
1.7.7.5

[PATCH 01/10] drm/radeon: document radeon_device.c

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

Adds documentation to most of the functions in
radeon_device.c

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/radeon_device.c |  344 +++++++++++++++++++++++++++++++-
 1 files changed, 341 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
index f654ba8..4cce4f4 100644
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -96,8 +96,12 @@ static const char radeon_family_name[][16] = {
 	"LAST",
 };
 
-/*
- * Clear GPU surface registers.
+/**
+ * radeon_surface_init - Clear GPU surface registers.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Clear GPU surface registers (r1xx-r5xx).
  */
 void radeon_surface_init(struct radeon_device *rdev)
 {
@@ -119,6 +123,13 @@ void radeon_surface_init(struct radeon_device *rdev)
 /*
  * GPU scratch registers helpers function.
  */
+/**
+ * radeon_scratch_init - Init scratch register driver information.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Init CP scratch register driver information (r1xx-r5xx)
+ */
 void radeon_scratch_init(struct radeon_device *rdev)
 {
 	int i;
@@ -136,6 +147,15 @@ void radeon_scratch_init(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * radeon_scratch_get - Allocate a scratch register
+ *
+ * @rdev: radeon_device pointer
+ * @reg: scratch register mmio offset
+ *
+ * Allocate a CP scratch register for use by the driver (all asics).
+ * Returns 0 on success or -EINVAL on failure.
+ */
 int radeon_scratch_get(struct radeon_device *rdev, uint32_t *reg)
 {
 	int i;
@@ -150,6 +170,14 @@ int radeon_scratch_get(struct radeon_device *rdev, uint32_t *reg)
 	return -EINVAL;
 }
 
+/**
+ * radeon_scratch_free - Free a scratch register
+ *
+ * @rdev: radeon_device pointer
+ * @reg: scratch register mmio offset
+ *
+ * Free a CP scratch register allocated for use by the driver (all asics)
+ */
 void radeon_scratch_free(struct radeon_device *rdev, uint32_t reg)
 {
 	int i;
@@ -162,6 +190,16 @@ void radeon_scratch_free(struct radeon_device *rdev, uint32_t reg)
 	}
 }
 
+/**
+ * radeon_wb_disable - Disable Writeback
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Disables Writeback (all asics).  Used for suspend.
+ * Writeback is the the method by which the the GPU updates special pages
+ * in memory with the status of certain GPU events (fences, ring pointers,
+ * etc.).
+ */
 void radeon_wb_disable(struct radeon_device *rdev)
 {
 	int r;
@@ -177,6 +215,17 @@ void radeon_wb_disable(struct radeon_device *rdev)
 	rdev->wb.enabled = false;
 }
 
+/**
+ * radeon_wb_fini - Disable Writeback and free memory
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Disables Writeback and frees the Writeback memory (all asics).
+ * Used at driver shutdown.
+ * Writeback is the the method by which the the GPU updates special pages
+ * in memory with the status of certain GPU events (fences, ring pointers,
+ * etc.).
+ */
 void radeon_wb_fini(struct radeon_device *rdev)
 {
 	radeon_wb_disable(rdev);
@@ -187,6 +236,18 @@ void radeon_wb_fini(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * radeon_wb_init- Init Writeback driver info and allocate memory
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Disables Writeback and frees the Writeback memory (all asics).
+ * Used at driver startup.
+ * Returns 0 on success or an -error on failure.
+ * Writeback is the the method by which the the GPU updates special pages
+ * in memory with the status of certain GPU events (fences, ring pointers,
+ * etc.).
+ */
 int radeon_wb_init(struct radeon_device *rdev)
 {
 	int r;
@@ -355,6 +416,15 @@ void radeon_gtt_location(struct radeon_device *rdev, struct radeon_mc *mc)
 /*
  * GPU helpers function.
  */
+/**
+ * radeon_card_posted - check if the hw has already been initialized
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Check if the asic has been initialized (all asics).
+ * Used at driver startup.
+ * Returns true if initialized or false if not.
+ */
 bool radeon_card_posted(struct radeon_device *rdev)
 {
 	uint32_t reg;
@@ -404,6 +474,14 @@ bool radeon_card_posted(struct radeon_device *rdev)
 
 }
 
+/**
+ * radeon_update_bandwidth_info - update display bandwidth params
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Used when sclk/mclk are switched or display modes are set.
+ * params are used to calculate display watermarks (all asics)
+ */
 void radeon_update_bandwidth_info(struct radeon_device *rdev)
 {
 	fixed20_12 a;
@@ -424,6 +502,15 @@ void radeon_update_bandwidth_info(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * radeon_boot_test_post_card - check and possibly initialize the hw
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Check if the asic is initialized and if not, attempt to initialize
+ * it (all asics).
+ * Returns true if initialized or false if not.
+ */
 bool radeon_boot_test_post_card(struct radeon_device *rdev)
 {
 	if (radeon_card_posted(rdev))
@@ -442,6 +529,16 @@ bool radeon_boot_test_post_card(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * radeon_dummy_page_init - init dummy page used by the driver
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Allocate the dummy page used by the driver (all asics).
+ * This dummy page is used by the driver as a filler for gart entries
+ * when pages are taken out of the GART
+ * Returns 0 on sucess, -ENOMEM on failure.
+ */
 int radeon_dummy_page_init(struct radeon_device *rdev)
 {
 	if (rdev->dummy_page.page)
@@ -460,6 +557,15 @@ int radeon_dummy_page_init(struct radeon_device *rdev)
 	return 0;
 }
 
+/**
+ * radeon_dummy_page_fini - free dummy page used by the driver
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Frees the dummy page used by the driver (all asics).
+ * This dummy page is used by the driver as a filler for gart entries
+ * when pages are taken out of the GART
+ */
 void radeon_dummy_page_fini(struct radeon_device *rdev)
 {
 	if (rdev->dummy_page.page == NULL)
@@ -472,6 +578,19 @@ void radeon_dummy_page_fini(struct radeon_device *rdev)
 
 
 /* ATOM accessor methods */
+/**
+ * cail_pll_read - read PLL register
+ *
+ * @info: atom card_info pointer
+ * @reg: PLL register offset
+ *
+ * Provides a PLL register accessor for the atom interpreter (r4xx+).
+ * Returns the value of the PLL register.
+ * ATOM is an interpreted byte code stored in tables in the vbios.  The
+ * driver registers callbacks to access registers and the interpreter
+ * in the driver parses the tables and executes then to program specific
+ * actions (set display modes, asic init, etc.).
+ */
 static uint32_t cail_pll_read(struct card_info *info, uint32_t reg)
 {
 	struct radeon_device *rdev = info->dev->dev_private;
@@ -481,6 +600,19 @@ static uint32_t cail_pll_read(struct card_info *info, uint32_t reg)
 	return r;
 }
 
+/**
+ * cail_pll_write - write PLL register
+ *
+ * @info: atom card_info pointer
+ * @reg: PLL register offset
+ * @val: value to write to the pll register
+ *
+ * Provides a PLL register accessor for the atom interpreter (r4xx+).
+ * ATOM is an interpreted byte code stored in tables in the vbios.  The
+ * driver registers callbacks to access registers and the interpreter
+ * in the driver parses the tables and executes then to program specific
+ * actions (set display modes, asic init, etc.).
+ */
 static void cail_pll_write(struct card_info *info, uint32_t reg, uint32_t val)
 {
 	struct radeon_device *rdev = info->dev->dev_private;
@@ -488,6 +620,19 @@ static void cail_pll_write(struct card_info *info, uint32_t reg, uint32_t val)
 	rdev->pll_wreg(rdev, reg, val);
 }
 
+/**
+ * cail_mc_read - read MC (Memory Controller) register
+ *
+ * @info: atom card_info pointer
+ * @reg: MC register offset
+ *
+ * Provides an MC register accessor for the atom interpreter (r4xx+).
+ * Returns the value of the MC register.
+ * ATOM is an interpreted byte code stored in tables in the vbios.  The
+ * driver registers callbacks to access registers and the interpreter
+ * in the driver parses the tables and executes then to program specific
+ * actions (set display modes, asic init, etc.).
+ */
 static uint32_t cail_mc_read(struct card_info *info, uint32_t reg)
 {
 	struct radeon_device *rdev = info->dev->dev_private;
@@ -497,6 +642,19 @@ static uint32_t cail_mc_read(struct card_info *info, uint32_t reg)
 	return r;
 }
 
+/**
+ * cail_mc_write - write MC (Memory Controller) register
+ *
+ * @info: atom card_info pointer
+ * @reg: MC register offset
+ * @val: value to write to the pll register
+ *
+ * Provides a MC register accessor for the atom interpreter (r4xx+).
+ * ATOM is an interpreted byte code stored in tables in the vbios.  The
+ * driver registers callbacks to access registers and the interpreter
+ * in the driver parses the tables and executes then to program specific
+ * actions (set display modes, asic init, etc.).
+ */
 static void cail_mc_write(struct card_info *info, uint32_t reg, uint32_t val)
 {
 	struct radeon_device *rdev = info->dev->dev_private;
@@ -504,6 +662,19 @@ static void cail_mc_write(struct card_info *info, uint32_t reg, uint32_t val)
 	rdev->mc_wreg(rdev, reg, val);
 }
 
+/**
+ * cail_reg_write - write MMIO register
+ *
+ * @info: atom card_info pointer
+ * @reg: MMIO register offset
+ * @val: value to write to the pll register
+ *
+ * Provides a MMIO register accessor for the atom interpreter (r4xx+).
+ * ATOM is an interpreted byte code stored in tables in the vbios.  The
+ * driver registers callbacks to access registers and the interpreter
+ * in the driver parses the tables and executes then to program specific
+ * actions (set display modes, asic init, etc.).
+ */
 static void cail_reg_write(struct card_info *info, uint32_t reg, uint32_t val)
 {
 	struct radeon_device *rdev = info->dev->dev_private;
@@ -511,6 +682,19 @@ static void cail_reg_write(struct card_info *info, uint32_t reg, uint32_t val)
 	WREG32(reg*4, val);
 }
 
+/**
+ * cail_reg_read - read MMIO register
+ *
+ * @info: atom card_info pointer
+ * @reg: MMIO register offset
+ *
+ * Provides an MMIO register accessor for the atom interpreter (r4xx+).
+ * Returns the value of the MMIO register.
+ * ATOM is an interpreted byte code stored in tables in the vbios.  The
+ * driver registers callbacks to access registers and the interpreter
+ * in the driver parses the tables and executes then to program specific
+ * actions (set display modes, asic init, etc.).
+ */
 static uint32_t cail_reg_read(struct card_info *info, uint32_t reg)
 {
 	struct radeon_device *rdev = info->dev->dev_private;
@@ -520,6 +704,19 @@ static uint32_t cail_reg_read(struct card_info *info, uint32_t reg)
 	return r;
 }
 
+/**
+ * cail_ioreg_write - write IO register
+ *
+ * @info: atom card_info pointer
+ * @reg: IO register offset
+ * @val: value to write to the pll register
+ *
+ * Provides a IO register accessor for the atom interpreter (r4xx+).
+ * ATOM is an interpreted byte code stored in tables in the vbios.  The
+ * driver registers callbacks to access registers and the interpreter
+ * in the driver parses the tables and executes then to program specific
+ * actions (set display modes, asic init, etc.).
+ */
 static void cail_ioreg_write(struct card_info *info, uint32_t reg, uint32_t val)
 {
 	struct radeon_device *rdev = info->dev->dev_private;
@@ -527,6 +724,19 @@ static void cail_ioreg_write(struct card_info *info, uint32_t reg, uint32_t val)
 	WREG32_IO(reg*4, val);
 }
 
+/**
+ * cail_ioreg_read - read IO register
+ *
+ * @info: atom card_info pointer
+ * @reg: IO register offset
+ *
+ * Provides an IO register accessor for the atom interpreter (r4xx+).
+ * Returns the value of the IO register.
+ * ATOM is an interpreted byte code stored in tables in the vbios.  The
+ * driver registers callbacks to access registers and the interpreter
+ * in the driver parses the tables and executes then to program specific
+ * actions (set display modes, asic init, etc.).
+ */
 static uint32_t cail_ioreg_read(struct card_info *info, uint32_t reg)
 {
 	struct radeon_device *rdev = info->dev->dev_private;
@@ -536,6 +746,20 @@ static uint32_t cail_ioreg_read(struct card_info *info, uint32_t reg)
 	return r;
 }
 
+/**
+ * radeon_atombios_init - init the driver info and callbacks for atombios
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Initializes the driver info and register access callbacks for the
+ * ATOM interpreter (r4xx+).
+ * Returns 0 on sucess, -ENOMEM on failure.
+ * Called at driver startup.
+ * ATOM is an interpreted byte code stored in tables in the vbios.  The
+ * driver registers callbacks to access registers and the interpreter
+ * in the driver parses the tables and executes then to program specific
+ * actions (set display modes, asic init, etc.).
+ */
 int radeon_atombios_init(struct radeon_device *rdev)
 {
 	struct card_info *atom_card_info =
@@ -569,6 +793,19 @@ int radeon_atombios_init(struct radeon_device *rdev)
 	return 0;
 }
 
+/**
+ * radeon_atombios_fini - free the driver info and callbacks for atombios
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Frees the driver info and register access callbacks for the ATOM
+ * interpreter (r4xx+).
+ * Called at driver shutdown.
+ * ATOM is an interpreted byte code stored in tables in the vbios.  The
+ * driver registers callbacks to access registers and the interpreter
+ * in the driver parses the tables and executes then to program specific
+ * actions (set display modes, asic init, etc.).
+ */
 void radeon_atombios_fini(struct radeon_device *rdev)
 {
 	if (rdev->mode_info.atom_context) {
@@ -578,17 +815,45 @@ void radeon_atombios_fini(struct radeon_device *rdev)
 	kfree(rdev->mode_info.atom_card_info);
 }
 
+/**
+ * radeon_combios_init - init the driver info for combios
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Initializes the driver info for combios (r1xx-r3xx).
+ * Returns 0 on sucess.
+ * Called at driver startup.
+ * COMBIOS is the bios format prior to ATOM.
+ */
 int radeon_combios_init(struct radeon_device *rdev)
 {
 	radeon_combios_initialize_bios_scratch_regs(rdev->ddev);
 	return 0;
 }
 
+/**
+ * radeon_combios_fini - free the driver info for combios
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Frees the driver info for combios (r1xx-r3xx).
+ * Called at driver shutdown.
+ * COMBIOS is the bios format prior to ATOM.
+ */
 void radeon_combios_fini(struct radeon_device *rdev)
 {
 }
 
-/* if we get transitioned to only one device, tak VGA back */
+/* if we get transitioned to only one device, take VGA back */
+/**
+ * radeon_vga_set_decode - enable/disable vga decode
+ *
+ * @cookie: radeon_device pointer
+ * @state: enable/disable vga decode
+ *
+ * Enable/disable vga decode (all asics).
+ * Returns VGA resource flags.
+ */
 static unsigned int radeon_vga_set_decode(void *cookie, bool state)
 {
 	struct radeon_device *rdev = cookie;
@@ -600,6 +865,14 @@ static unsigned int radeon_vga_set_decode(void *cookie, bool state)
 		return VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM;
 }
 
+/**
+ * radeon_check_arguments - validate module params
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Validates certain module parameters and updates
+ * the associated values used by the driver (all asics).
+ */
 void radeon_check_arguments(struct radeon_device *rdev)
 {
 	/* vramlimit must be a power of two */
@@ -666,6 +939,15 @@ void radeon_check_arguments(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * radeon_switcheroo_set_state - set switcheroo state
+ *
+ * @pdev: pci dev pointer
+ * @state: vga switcheroo state
+ *
+ * Callback for the switcheroo driver.  Suspends or resumes the
+ * the asics before or after it is powered up using ACPI methods.
+ */
 static void radeon_switcheroo_set_state(struct pci_dev *pdev, enum vga_switcheroo_state state)
 {
 	struct drm_device *dev = pci_get_drvdata(pdev);
@@ -686,6 +968,15 @@ static void radeon_switcheroo_set_state(struct pci_dev *pdev, enum vga_switchero
 	}
 }
 
+/**
+ * radeon_switcheroo_can_switch - see if switcheroo state can change
+ *
+ * @pdev: pci dev pointer
+ *
+ * Callback for the switcheroo driver.  Check of the switcheroo
+ * state can be changed.
+ * Returns true if the state can be changed, false if not.
+ */
 static bool radeon_switcheroo_can_switch(struct pci_dev *pdev)
 {
 	struct drm_device *dev = pci_get_drvdata(pdev);
@@ -703,6 +994,18 @@ static const struct vga_switcheroo_client_ops radeon_switcheroo_ops = {
 	.can_switch = radeon_switcheroo_can_switch,
 };
 
+/**
+ * radeon_device_init - initialize the driver
+ *
+ * @rdev: radeon_device pointer
+ * @pdev: drm dev pointer
+ * @pdev: pci dev pointer
+ * @flags: driver flags
+ *
+ * Initializes the driver info and hw (all asics).
+ * Returns 0 for success or an error on failure.
+ * Called at driver startup.
+ */
 int radeon_device_init(struct radeon_device *rdev,
 		       struct drm_device *ddev,
 		       struct pci_dev *pdev,
@@ -846,6 +1149,14 @@ int radeon_device_init(struct radeon_device *rdev,
 
 static void radeon_debugfs_remove_files(struct radeon_device *rdev);
 
+/**
+ * radeon_device_fini - tear down the driver
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Tear down the driver info (all asics).
+ * Called at driver shutdown.
+ */
 void radeon_device_fini(struct radeon_device *rdev)
 {
 	DRM_INFO("radeon: finishing device.\n");
@@ -867,6 +1178,16 @@ void radeon_device_fini(struct radeon_device *rdev)
 /*
  * Suspend & resume.
  */
+/**
+ * radeon_suspend_kms - initiate device suspend
+ *
+ * @pdev: drm dev pointer
+ * @state: suspend state
+ *
+ * Puts the hw in the suspend state (all asics).
+ * Returns 0 for success or an error on failure.
+ * Called at driver suspend.
+ */
 int radeon_suspend_kms(struct drm_device *dev, pm_message_t state)
 {
 	struct radeon_device *rdev;
@@ -941,6 +1262,15 @@ int radeon_suspend_kms(struct drm_device *dev, pm_message_t state)
 	return 0;
 }
 
+/**
+ * radeon_resume_kms - initiate device resume
+ *
+ * @pdev: drm dev pointer
+ *
+ * Bring the hw back to operating state (all asics).
+ * Returns 0 for success or an error on failure.
+ * Called at driver resume.
+ */
 int radeon_resume_kms(struct drm_device *dev)
 {
 	struct drm_connector *connector;
@@ -983,6 +1313,14 @@ int radeon_resume_kms(struct drm_device *dev)
 	return 0;
 }
 
+/**
+ * radeon_gpu_reset - reset the asic
+ *
+ * @rdev: radeon device pointer
+ *
+ * Attempt the reset the GPU if it has hung (all asics).
+ * Returns 0 for success or an error on failure.
+ */
 int radeon_gpu_reset(struct radeon_device *rdev)
 {
 	int r;
-- 
1.7.7.5

[PATCH 02/10] drm/radeon: document radeon_kms.c

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

Adds documentation to most of the functions in
radeon_kms.c

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/radeon_kms.c |  126 +++++++++++++++++++++++++++++++++++
 1 files changed, 126 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_kms.c b/drivers/gpu/drm/radeon/radeon_kms.c
index 18b81d6..1d73f16 100644
--- a/drivers/gpu/drm/radeon/radeon_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_kms.c
@@ -33,6 +33,17 @@
 #include <linux/vga_switcheroo.h>
 #include <linux/slab.h>
 
+/**
+ * radeon_driver_unload_kms - Main unload function for KMS.
+ *
+ * @dev: drm dev pointer
+ *
+ * This is the main unload function for KMS (all asics).
+ * It calls radeon_modeset_fini() to tear down the
+ * displays, and radeon_device_fini() to tear down
+ * the rest of the device (CP, writeback, etc.).
+ * Returns 0 on success.
+ */
 int radeon_driver_unload_kms(struct drm_device *dev)
 {
 	struct radeon_device *rdev = dev->dev_private;
@@ -46,6 +57,19 @@ int radeon_driver_unload_kms(struct drm_device *dev)
 	return 0;
 }
 
+/**
+ * radeon_driver_load_kms - Main load function for KMS.
+ *
+ * @dev: drm dev pointer
+ * @flags: device flags
+ *
+ * This is the main load function for KMS (all asics).
+ * It calls radeon_device_init() to set up the non-display
+ * parts of the chip (asic init, CP, writeback, etc.), and
+ * radeon_modeset_init() to set up the display parts
+ * (crtcs, encoders, hotplug detect, etc.).
+ * Returns 0 on success, error on failure.
+ */
 int radeon_driver_load_kms(struct drm_device *dev, unsigned long flags)
 {
 	struct radeon_device *rdev;
@@ -96,6 +120,16 @@ out:
 	return r;
 }
 
+/**
+ * radeon_set_filp_rights - Set filp right.
+ *
+ * @dev: drm dev pointer
+ * @owner: drm file
+ * @applier: drm file
+ * @value: value
+ *
+ * Sets the filp rights for the device (all asics).
+ */
 static void radeon_set_filp_rights(struct drm_device *dev,
 				   struct drm_file **owner,
 				   struct drm_file *applier,
@@ -118,6 +152,18 @@ static void radeon_set_filp_rights(struct drm_device *dev,
 /*
  * Userspace get information ioctl
  */
+/**
+ * radeon_info_ioctl - answer a device specific request.
+ *
+ * @rdev: radeon device pointer
+ * @data: request object
+ * @filp: drm filp
+ *
+ * This function is used to pass device specific parameters to the userspace
+ * drivers.  Examples include: pci device id, pipeline parms, tiling params,
+ * etc. (all asics).
+ * Returns 0 on success, -EINVAL on failure.
+ */
 int radeon_info_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 {
 	struct radeon_device *rdev = dev->dev_private;
@@ -301,16 +347,40 @@ int radeon_info_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 /*
  * Outdated mess for old drm with Xorg being in charge (void function now).
  */
+/**
+ * radeon_driver_firstopen_kms - drm callback for first open
+ *
+ * @dev: drm dev pointer
+ *
+ * Nothing to be done for KMS (all asics).
+ * Returns 0 on success.
+ */
 int radeon_driver_firstopen_kms(struct drm_device *dev)
 {
 	return 0;
 }
 
+/**
+ * radeon_driver_firstopen_kms - drm callback for last close
+ *
+ * @dev: drm dev pointer
+ *
+ * Switch vga switcheroo state after last close (all asics).
+ */
 void radeon_driver_lastclose_kms(struct drm_device *dev)
 {
 	vga_switcheroo_process_delayed_switch();
 }
 
+/**
+ * radeon_driver_open_kms - drm callback for open
+ *
+ * @dev: drm dev pointer
+ * @file_priv: drm file
+ *
+ * On device open, init vm on cayman+ (all asics).
+ * Returns 0 on success, error on failure.
+ */
 int radeon_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv)
 {
 	struct radeon_device *rdev = dev->dev_private;
@@ -339,6 +409,14 @@ int radeon_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv)
 	return 0;
 }
 
+/**
+ * radeon_driver_postclose_kms - drm callback for post close
+ *
+ * @dev: drm dev pointer
+ * @file_priv: drm file
+ *
+ * On device post close, tear down vm on cayman+ (all asics).
+ */
 void radeon_driver_postclose_kms(struct drm_device *dev,
 				 struct drm_file *file_priv)
 {
@@ -354,6 +432,15 @@ void radeon_driver_postclose_kms(struct drm_device *dev,
 	}
 }
 
+/**
+ * radeon_driver_preclose_kms - drm callback for pre close
+ *
+ * @dev: drm dev pointer
+ * @file_priv: drm file
+ *
+ * On device pre close, tear down hyperz and cmask filps on r1xx-r5xx
+ * (all asics).
+ */
 void radeon_driver_preclose_kms(struct drm_device *dev,
 				struct drm_file *file_priv)
 {
@@ -367,6 +454,15 @@ void radeon_driver_preclose_kms(struct drm_device *dev,
 /*
  * VBlank related functions.
  */
+/**
+ * radeon_get_vblank_counter_kms - get frame count
+ *
+ * @dev: drm dev pointer
+ * @crtc: crtc to get the frame count from
+ *
+ * Gets the frame count on the requested crtc (all asics).
+ * Returns frame count on success, -EINVAL on failure.
+ */
 u32 radeon_get_vblank_counter_kms(struct drm_device *dev, int crtc)
 {
 	struct radeon_device *rdev = dev->dev_private;
@@ -379,6 +475,15 @@ u32 radeon_get_vblank_counter_kms(struct drm_device *dev, int crtc)
 	return radeon_get_vblank_counter(rdev, crtc);
 }
 
+/**
+ * radeon_enable_vblank_kms - enable vblank interrupt
+ *
+ * @dev: drm dev pointer
+ * @crtc: crtc to enable vblank interrupt for
+ *
+ * Enable the interrupt on the requested crtc (all asics).
+ * Returns 0 on success, -EINVAL on failure.
+ */
 int radeon_enable_vblank_kms(struct drm_device *dev, int crtc)
 {
 	struct radeon_device *rdev = dev->dev_private;
@@ -397,6 +502,14 @@ int radeon_enable_vblank_kms(struct drm_device *dev, int crtc)
 	return r;
 }
 
+/**
+ * radeon_disable_vblank_kms - disable vblank interrupt
+ *
+ * @dev: drm dev pointer
+ * @crtc: crtc to disable vblank interrupt for
+ *
+ * Disable the interrupt on the requested crtc (all asics).
+ */
 void radeon_disable_vblank_kms(struct drm_device *dev, int crtc)
 {
 	struct radeon_device *rdev = dev->dev_private;
@@ -413,6 +526,19 @@ void radeon_disable_vblank_kms(struct drm_device *dev, int crtc)
 	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
 }
 
+/**
+ * radeon_get_vblank_timestamp_kms - get vblank timestamp
+ *
+ * @dev: drm dev pointer
+ * @crtc: crtc to get the timestamp for
+ * @max_error: max error
+ * @vblank_time: time value
+ * @flags: flags passed to the driver
+ *
+ * Gets the timestamp on the requested crtc based on the
+ * scanout position.  (all asics).
+ * Returns postive status flags on success, negative error on failure.
+ */
 int radeon_get_vblank_timestamp_kms(struct drm_device *dev, int crtc,
 				    int *max_error,
 				    struct timeval *vblank_time,
-- 
1.7.7.5

[PATCH 03/10] drm/radeon: document radeon_irq_kms.c

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

Adds documentation to most of the functions in
radeon_irq_kms.c

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/radeon_irq_kms.c |  150 +++++++++++++++++++++++++++++++
 1 files changed, 150 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_irq_kms.c b/drivers/gpu/drm/radeon/radeon_irq_kms.c
index 6664514..afaa172 100644
--- a/drivers/gpu/drm/radeon/radeon_irq_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_irq_kms.c
@@ -34,6 +34,15 @@
 
 #define RADEON_WAIT_IDLE_TIMEOUT 200
 
+/**
+ * radeon_driver_irq_handler_kms - irq handler for KMS
+ *
+ * @DRM_IRQ_ARGS: args
+ *
+ * This is the irq handler for the radeon KMS driver (all asics).
+ * radeon_irq_process is a macro that points to the per-asic
+ * irq handler callback.
+ */
 irqreturn_t radeon_driver_irq_handler_kms(DRM_IRQ_ARGS)
 {
 	struct drm_device *dev = (struct drm_device *) arg;
@@ -45,6 +54,17 @@ irqreturn_t radeon_driver_irq_handler_kms(DRM_IRQ_ARGS)
 /*
  * Handle hotplug events outside the interrupt handler proper.
  */
+/**
+ * radeon_hotplug_work_func - display hotplug work handler
+ *
+ * @work: work struct
+ *
+ * This is the hot plug event work handler (all asics).
+ * The work gets scheduled from the irq handler if there
+ * was a hot plug interrupt.  It walks the connector table
+ * and calls the hotplug handler for each one, then sends
+ * a drm hotplug event to alert userspace.
+ */
 static void radeon_hotplug_work_func(struct work_struct *work)
 {
 	struct radeon_device *rdev = container_of(work, struct radeon_device,
@@ -61,6 +81,14 @@ static void radeon_hotplug_work_func(struct work_struct *work)
 	drm_helper_hpd_irq_event(dev);
 }
 
+/**
+ * radeon_driver_irq_preinstall_kms - drm irq preinstall callback
+ *
+ * @dev: drm dev pointer
+ *
+ * Gets the hw ready to enable irqs (all asics).
+ * This function disables all interrupt sources on the GPU.
+ */
 void radeon_driver_irq_preinstall_kms(struct drm_device *dev)
 {
 	struct radeon_device *rdev = dev->dev_private;
@@ -85,12 +113,27 @@ void radeon_driver_irq_preinstall_kms(struct drm_device *dev)
 	radeon_irq_process(rdev);
 }
 
+/**
+ * radeon_driver_irq_postinstall_kms - drm irq preinstall callback
+ *
+ * @dev: drm dev pointer
+ *
+ * Handles stuff to be done after enabling irqs (all asics).
+ * Returns 0 on success.
+ */
 int radeon_driver_irq_postinstall_kms(struct drm_device *dev)
 {
 	dev->max_vblank_count = 0x001fffff;
 	return 0;
 }
 
+/**
+ * radeon_driver_irq_uninstall_kms - drm irq uninstall callback
+ *
+ * @dev: drm dev pointer
+ *
+ * This function disables all interrupt sources on the GPU (all asics).
+ */
 void radeon_driver_irq_uninstall_kms(struct drm_device *dev)
 {
 	struct radeon_device *rdev = dev->dev_private;
@@ -116,6 +159,16 @@ void radeon_driver_irq_uninstall_kms(struct drm_device *dev)
 	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
 }
 
+/**
+ * radeon_msi_ok - asic specific msi checks
+ *
+ * @rdev: radeon device pointer
+ *
+ * Handles asic specific MSI checks to determine if
+ * MSIs should be enabled on a particular chip (all asics).
+ * Returns true if MSIs should be enabled, false if MSIs
+ * should not be enabled.
+ */
 static bool radeon_msi_ok(struct radeon_device *rdev)
 {
 	/* RV370/RV380 was first asic with MSI support */
@@ -168,6 +221,14 @@ static bool radeon_msi_ok(struct radeon_device *rdev)
 	return true;
 }
 
+/**
+ * radeon_irq_kms_init - init driver interrupt info
+ *
+ * @rdev: radeon device pointer
+ *
+ * Sets up the work irq handlers, vblank init, MSIs, etc. (all asics).
+ * Returns 0 for success, error for failure.
+ */
 int radeon_irq_kms_init(struct radeon_device *rdev)
 {
 	int r = 0;
@@ -200,6 +261,13 @@ int radeon_irq_kms_init(struct radeon_device *rdev)
 	return 0;
 }
 
+/**
+ * radeon_irq_kms_fini - tear down driver interrrupt info
+ *
+ * @rdev: radeon device pointer
+ *
+ * Tears down the work irq handlers, vblank handlers, MSIs, etc. (all asics).
+ */
 void radeon_irq_kms_fini(struct radeon_device *rdev)
 {
 	drm_vblank_cleanup(rdev->ddev);
@@ -212,6 +280,16 @@ void radeon_irq_kms_fini(struct radeon_device *rdev)
 	flush_work_sync(&rdev->hotplug_work);
 }
 
+/**
+ * radeon_irq_kms_sw_irq_get - enable software interrupt
+ *
+ * @rdev: radeon device pointer
+ * @ring: ring whose interrupt you want to enable
+ *
+ * Enables the software interrupt for a specific ring (all asics).
+ * The software interrupt is generally used to signal a fence on
+ * a particular ring.
+ */
 void radeon_irq_kms_sw_irq_get(struct radeon_device *rdev, int ring)
 {
 	unsigned long irqflags;
@@ -226,6 +304,16 @@ void radeon_irq_kms_sw_irq_get(struct radeon_device *rdev, int ring)
 	}
 }
 
+/**
+ * radeon_irq_kms_sw_irq_put - disable software interrupt
+ *
+ * @rdev: radeon device pointer
+ * @ring: ring whose interrupt you want to disable
+ *
+ * Disables the software interrupt for a specific ring (all asics).
+ * The software interrupt is generally used to signal a fence on
+ * a particular ring.
+ */
 void radeon_irq_kms_sw_irq_put(struct radeon_device *rdev, int ring)
 {
 	unsigned long irqflags;
@@ -240,6 +328,15 @@ void radeon_irq_kms_sw_irq_put(struct radeon_device *rdev, int ring)
 	}
 }
 
+/**
+ * radeon_irq_kms_pflip_irq_get - enable pageflip interrupt
+ *
+ * @rdev: radeon device pointer
+ * @crtc: crtc whose interrupt you want to enable
+ *
+ * Enables the pageflip interrupt for a specific crtc (all asics).
+ * For pageflips we use the vblank interrupt source.
+ */
 void radeon_irq_kms_pflip_irq_get(struct radeon_device *rdev, int crtc)
 {
 	unsigned long irqflags;
@@ -257,6 +354,15 @@ void radeon_irq_kms_pflip_irq_get(struct radeon_device *rdev, int crtc)
 	}
 }
 
+/**
+ * radeon_irq_kms_pflip_irq_put - disable pageflip interrupt
+ *
+ * @rdev: radeon device pointer
+ * @crtc: crtc whose interrupt you want to disable
+ *
+ * Disables the pageflip interrupt for a specific crtc (all asics).
+ * For pageflips we use the vblank interrupt source.
+ */
 void radeon_irq_kms_pflip_irq_put(struct radeon_device *rdev, int crtc)
 {
 	unsigned long irqflags;
@@ -274,6 +380,14 @@ void radeon_irq_kms_pflip_irq_put(struct radeon_device *rdev, int crtc)
 	}
 }
 
+/**
+ * radeon_irq_kms_enable_afmt - enable audio format change interrupt
+ *
+ * @rdev: radeon device pointer
+ * @block: afmt block whose interrupt you want to enable
+ *
+ * Enables the afmt change interrupt for a specific afmt block (all asics).
+ */
 void radeon_irq_kms_enable_afmt(struct radeon_device *rdev, int block)
 {
 	unsigned long irqflags;
@@ -285,6 +399,14 @@ void radeon_irq_kms_enable_afmt(struct radeon_device *rdev, int block)
 
 }
 
+/**
+ * radeon_irq_kms_disable_afmt - disable audio format change interrupt
+ *
+ * @rdev: radeon device pointer
+ * @block: afmt block whose interrupt you want to disable
+ *
+ * Disables the afmt change interrupt for a specific afmt block (all asics).
+ */
 void radeon_irq_kms_disable_afmt(struct radeon_device *rdev, int block)
 {
 	unsigned long irqflags;
@@ -295,6 +417,14 @@ void radeon_irq_kms_disable_afmt(struct radeon_device *rdev, int block)
 	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
 }
 
+/**
+ * radeon_irq_kms_enable_hpd - enable hotplug detect interrupt
+ *
+ * @rdev: radeon device pointer
+ * @hpd_mask: mask of hpd pins you want to enable.
+ *
+ * Enables the hotplug detect interrupt for a specific hpd pin (all asics).
+ */
 void radeon_irq_kms_enable_hpd(struct radeon_device *rdev, unsigned hpd_mask)
 {
 	unsigned long irqflags;
@@ -307,6 +437,14 @@ void radeon_irq_kms_enable_hpd(struct radeon_device *rdev, unsigned hpd_mask)
 	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
 }
 
+/**
+ * radeon_irq_kms_disable_hpd - disable hotplug detect interrupt
+ *
+ * @rdev: radeon device pointer
+ * @hpd_mask: mask of hpd pins you want to disable.
+ *
+ * Disables the hotplug detect interrupt for a specific hpd pin (all asics).
+ */
 void radeon_irq_kms_disable_hpd(struct radeon_device *rdev, unsigned hpd_mask)
 {
 	unsigned long irqflags;
@@ -319,6 +457,18 @@ void radeon_irq_kms_disable_hpd(struct radeon_device *rdev, unsigned hpd_mask)
 	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
 }
 
+/**
+ * radeon_irq_kms_wait_gui_idle - waits for drawing engine to be idle
+ *
+ * @rdev: radeon device pointer
+ *
+ * Enabled the GUI idle interrupt and waits for it to fire (r6xx+).
+ * This is currently used to make sure the 3D engine is idle for power
+ * management, but should be replaces with proper fence waits.
+ * GUI idle interrupts don't work very well on pre-r6xx hw and it also
+ * does not take into account other aspects of the chip that may be busy.
+ * DO NOT USE GOING FORWARD.
+ */
 int radeon_irq_kms_wait_gui_idle(struct radeon_device *rdev)
 {
 	unsigned long irqflags;
-- 
1.7.7.5

[PATCH 04/10] drm/radeon: document radeon_asic.c

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

Adds documentation to most of the functions in
radeon_asic.c

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/radeon_asic.c |   46 ++++++++++++++++++++++++++++++++++
 1 files changed, 46 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_asic.c b/drivers/gpu/drm/radeon/radeon_asic.c
index f533df5..973417c 100644
--- a/drivers/gpu/drm/radeon/radeon_asic.c
+++ b/drivers/gpu/drm/radeon/radeon_asic.c
@@ -40,6 +40,16 @@
 /*
  * Registers accessors functions.
  */
+/**
+ * radeon_invalid_rreg - dummy reg read function
+ *
+ * @rdev: radeon device pointer
+ * @reg: offset of register
+ *
+ * Dummy register read function.  Used for register blocks
+ * that certain asics don't have (all asics).
+ * Returns the value in the register.
+ */
 static uint32_t radeon_invalid_rreg(struct radeon_device *rdev, uint32_t reg)
 {
 	DRM_ERROR("Invalid callback to read register 0x%04X\n", reg);
@@ -47,6 +57,16 @@ static uint32_t radeon_invalid_rreg(struct radeon_device *rdev, uint32_t reg)
 	return 0;
 }
 
+/**
+ * radeon_invalid_wreg - dummy reg write function
+ *
+ * @rdev: radeon device pointer
+ * @reg: offset of register
+ * @v: value to write to the register
+ *
+ * Dummy register read function.  Used for register blocks
+ * that certain asics don't have (all asics).
+ */
 static void radeon_invalid_wreg(struct radeon_device *rdev, uint32_t reg, uint32_t v)
 {
 	DRM_ERROR("Invalid callback to write register 0x%04X with 0x%08X\n",
@@ -54,6 +74,14 @@ static void radeon_invalid_wreg(struct radeon_device *rdev, uint32_t reg, uint32
 	BUG_ON(1);
 }
 
+/**
+ * radeon_register_accessor_init - sets up the register accessor callbacks
+ *
+ * @rdev: radeon device pointer
+ *
+ * Sets up the register accessor callbacks for various register
+ * apertures.  Not all asics have all apertures (all asics).
+ */
 static void radeon_register_accessor_init(struct radeon_device *rdev)
 {
 	rdev->mc_rreg = &radeon_invalid_rreg;
@@ -102,6 +130,14 @@ static void radeon_register_accessor_init(struct radeon_device *rdev)
 
 
 /* helper to disable agp */
+/**
+ * radeon_agp_disable - AGP disable helper function
+ *
+ * @rdev: radeon device pointer
+ *
+ * Removes AGP flags and changes the gart callbacks on AGP
+ * cards when using the internal gart rather than AGP (all asics).
+ */
 void radeon_agp_disable(struct radeon_device *rdev)
 {
 	rdev->flags &= ~RADEON_IS_AGP;
@@ -1608,6 +1644,16 @@ static struct radeon_asic si_asic = {
 	},
 };
 
+/**
+ * radeon_asic_init - register asic specific callbacks
+ *
+ * @rdev: radeon device pointer
+ *
+ * Registers the appropriate asic specific callbacks for each
+ * chip family.  Also sets other asics specific info like the number
+ * of crtcs and the register aperture accessors (all asics).
+ * Returns 0 for success.
+ */
 int radeon_asic_init(struct radeon_device *rdev)
 {
 	radeon_register_accessor_init(rdev);
-- 
1.7.7.5

[PATCH 05/10] drm/radeon: document radeon_fence.c

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

Adds documentation to most of the functions in
radeon_fence.c

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/radeon_fence.c |  373 +++++++++++++++++++++++++++++++++
 1 files changed, 373 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_fence.c b/drivers/gpu/drm/radeon/radeon_fence.c
index 67f6fa9..604352e 100644
--- a/drivers/gpu/drm/radeon/radeon_fence.c
+++ b/drivers/gpu/drm/radeon/radeon_fence.c
@@ -40,6 +40,22 @@
 #include "radeon.h"
 #include "radeon_trace.h"
 
+/**
+ * radeon_fence_write - write a fence value
+ *
+ * @rdev: radeon_device pointer
+ * @seq: sequence number to write
+ * @ring: ring index the fence is associated with
+ *
+ * Writes a fence value to memory or a scratch register (all asics).
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 static void radeon_fence_write(struct radeon_device *rdev, u32 seq, int ring)
 {
 	if (rdev->wb.enabled) {
@@ -49,6 +65,22 @@ static void radeon_fence_write(struct radeon_device *rdev, u32 seq, int ring)
 	}
 }
 
+/**
+ * radeon_fence_read - read a fence value
+ *
+ * @rdev: radeon_device pointer
+ * @ring: ring index the fence is associated with
+ *
+ * Reads a fence value from memory or a scratch register (all asics).
+ * Returns the value of the fence read from memory or register.
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 static u32 radeon_fence_read(struct radeon_device *rdev, int ring)
 {
 	u32 seq = 0;
@@ -61,6 +93,23 @@ static u32 radeon_fence_read(struct radeon_device *rdev, int ring)
 	return seq;
 }
 
+/**
+ * radeon_fence_emit - emit a fence on the requested ring
+ *
+ * @rdev: radeon_device pointer
+ * @fence: radeon fence object
+ * @ring: ring index the fence is associated with
+ *
+ * Emits a fence command on the requested ring (all asics).
+ * Returns 0 on success, -ENOMEM on failure.
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 int radeon_fence_emit(struct radeon_device *rdev,
 		      struct radeon_fence **fence,
 		      int ring)
@@ -79,6 +128,22 @@ int radeon_fence_emit(struct radeon_device *rdev,
 	return 0;
 }
 
+/**
+ * radeon_fence_process - process a fence
+ *
+ * @rdev: radeon_device pointer
+ * @ring: ring index the fence is associated with
+ *
+ * Checks the current fence value and wakes the fence queue
+ * if the sequence number has increased (all asics).
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 void radeon_fence_process(struct radeon_device *rdev, int ring)
 {
 	uint64_t seq, last_seq;
@@ -139,6 +204,20 @@ void radeon_fence_process(struct radeon_device *rdev, int ring)
 	}
 }
 
+/**
+ * radeon_fence_destroy - destroy a fence
+ *
+ * @kref: fence kref
+ *
+ * Frees the fence object (all asics).
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 static void radeon_fence_destroy(struct kref *kref)
 {
 	struct radeon_fence *fence;
@@ -147,6 +226,27 @@ static void radeon_fence_destroy(struct kref *kref)
 	kfree(fence);
 }
 
+/**
+ * radeon_fence_seq_signaled - check if a fence sequeuce number has signaled
+ *
+ * @rdev: radeon device pointer
+ * @seq: sequence number
+ * @ring: ring index the fence is associated with
+ *
+ * Check if the last singled fence sequnce number is >= the requested
+ * sequence number (all asics).
+ * Returns true if the fence has signaled (current fence value
+ * is >= requested value) or false if it has not (current fence
+ * value is < the requested value.  Helper function for
+ * radeon_fence_signaled().
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 static bool radeon_fence_seq_signaled(struct radeon_device *rdev,
 				      u64 seq, unsigned ring)
 {
@@ -161,6 +261,21 @@ static bool radeon_fence_seq_signaled(struct radeon_device *rdev,
 	return false;
 }
 
+/**
+ * radeon_fence_signaled - check if a fence has signaled
+ *
+ * @fence: radeon fence object
+ *
+ * Check if the requested fence has signaled (all asics).
+ * Returns true if the fence has signaled or false if it has not.
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 bool radeon_fence_signaled(struct radeon_fence *fence)
 {
 	if (!fence) {
@@ -176,6 +291,27 @@ bool radeon_fence_signaled(struct radeon_fence *fence)
 	return false;
 }
 
+/**
+ * radeon_fence_wait_seq - wait for a specific sequence number
+ *
+ * @rdev: radeon device pointer
+ * @target_seq: sequence number we want to wait for
+ * @ring: ring index the fence is associated with
+ * @intr: use interrupt or not
+ * @lock_ring: whether the ring should be locked or not
+ *
+ * Wait for the requested sequence number to be written (all asics).
+ * If @intr is true, use an interrupt to wake up.  Helper function
+ * for radeon_fence_wait(), et al.
+ * Returns 0 if the sequence number has passed, error for all other cases.
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 static int radeon_fence_wait_seq(struct radeon_device *rdev, u64 target_seq,
 				 unsigned ring, bool intr, bool lock_ring)
 {
@@ -271,6 +407,23 @@ static int radeon_fence_wait_seq(struct radeon_device *rdev, u64 target_seq,
 	return 0;
 }
 
+/**
+ * radeon_fence_wait - wait for a fence to signal
+ *
+ * @fence: radeon fence object
+ * @intr: use interrupt or not
+ *
+ * Wait for the requested fence to signal (all asics).
+ * If @intr is true, use an interrupt to wake up.
+ * Returns 0 if the fence has passed, error for all other cases.
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 int radeon_fence_wait(struct radeon_fence *fence, bool intr)
 {
 	int r;
@@ -301,6 +454,26 @@ static bool radeon_fence_any_seq_signaled(struct radeon_device *rdev, u64 *seq)
 	return false;
 }
 
+/**
+ * radeon_fence_wait_any_seq - wait for a sequence number on any ring
+ *
+ * @rdev: radeon device pointer
+ * @target_seq: sequence number(s) we want to wait for
+ * @intr: use interrupt or not
+ *
+ * Wait for the requested sequence number(s) to be written by any ring
+ * (all asics).  Sequnce number array is indexed by ring id.
+ * If @intr is true, use an interrupt to wake up.  Helper function
+ * for radeon_fence_wait_any(), et al.
+ * Returns 0 if the sequence number has passed, error for all other cases.
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 static int radeon_fence_wait_any_seq(struct radeon_device *rdev,
 				     u64 *target_seq, bool intr)
 {
@@ -410,6 +583,25 @@ static int radeon_fence_wait_any_seq(struct radeon_device *rdev,
 	return 0;
 }
 
+/**
+ * radeon_fence_wait_any - wait for a fence to signal on any ring
+ *
+ * @rdev: radeon device pointer
+ * @fences: radeon fence object(s)
+ * @intr: use interrupt or not
+ *
+ * Wait for any requested fence to signal (all asics).  Fence
+ * array is indexed by ring id. If @intr is true, use an interrupt
+ * to wake up.  Used by the suballocator.
+ * Returns 0 if any fence has passed, error for all other cases.
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 int radeon_fence_wait_any(struct radeon_device *rdev,
 			  struct radeon_fence **fences,
 			  bool intr)
@@ -440,6 +632,22 @@ int radeon_fence_wait_any(struct radeon_device *rdev,
 	return 0;
 }
 
+/**
+ * radeon_fence_wait_next_locked - wait for the next fence to signal
+ *
+ * @rdev: radeon device pointer
+ * @ring: ring index the fence is associated with
+ *
+ * Wait for the next fence on the requested ring to signal (all asics).
+ * Returns 0 if the next fence has passed, error for all other cases.
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 int radeon_fence_wait_next_locked(struct radeon_device *rdev, int ring)
 {
 	uint64_t seq;
@@ -457,6 +665,22 @@ int radeon_fence_wait_next_locked(struct radeon_device *rdev, int ring)
 	return radeon_fence_wait_seq(rdev, seq, ring, false, false);
 }
 
+/**
+ * radeon_fence_wait_empty_locked - wait for all fences to signal
+ *
+ * @rdev: radeon device pointer
+ * @ring: ring index the fence is associated with
+ *
+ * Wait for all fences on the requested ring to signal (all asics).
+ * Returns 0 if the fences have passed, error for all other cases.
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 int radeon_fence_wait_empty_locked(struct radeon_device *rdev, int ring)
 {
 	/* We are not protected by ring lock when reading current seq
@@ -468,12 +692,41 @@ int radeon_fence_wait_empty_locked(struct radeon_device *rdev, int ring)
 				     ring, false, false);
 }
 
+/**
+ * radeon_fence_ref - take a ref on a fence
+ *
+ * @fence: radeon fence object
+ *
+ * Take a reference on a fence (all asics).
+ * Returns the fence.
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 struct radeon_fence *radeon_fence_ref(struct radeon_fence *fence)
 {
 	kref_get(&fence->kref);
 	return fence;
 }
 
+/**
+ * radeon_fence_unref - remove a ref on a fence
+ *
+ * @fence: radeon fence object
+ *
+ * Remove a reference on a fence (all asics).
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 void radeon_fence_unref(struct radeon_fence **fence)
 {
 	struct radeon_fence *tmp = *fence;
@@ -484,6 +737,22 @@ void radeon_fence_unref(struct radeon_fence **fence)
 	}
 }
 
+/**
+ * radeon_fence_count_emitted - get the count of emitted fences
+ *
+ * @rdev: radeon device pointer
+ * @ring: ring index the fence is associated with
+ *
+ * Get the number of fences emitted on the requested ring (all asics).
+ * Returns the number of emitted fences on the ring.
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 unsigned radeon_fence_count_emitted(struct radeon_device *rdev, int ring)
 {
 	uint64_t emitted;
@@ -501,6 +770,24 @@ unsigned radeon_fence_count_emitted(struct radeon_device *rdev, int ring)
 	return (unsigned)emitted;
 }
 
+/**
+ * radeon_fence_need_sync - do we need a semaphore
+ *
+ * @fence: radeon fence object
+ * @dst_ring: which ring to check against
+ *
+ * Check if the fence needs to be synced against another ring
+ * (all asics).  If so, we need to emit a semaphore.
+ * Returns true if we need to sync with another ring, false if
+ * not.
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 bool radeon_fence_need_sync(struct radeon_fence *fence, int dst_ring)
 {
 	struct radeon_fence_driver *fdrv;
@@ -522,6 +809,22 @@ bool radeon_fence_need_sync(struct radeon_fence *fence, int dst_ring)
 	return true;
 }
 
+/**
+ * radeon_fence_note_sync - record the sync point
+ *
+ * @fence: radeon fence object
+ * @dst_ring: which ring to check against
+ *
+ * Note the sequence number at which point the fence will
+ * be synced with the requested ring (all asics).
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 void radeon_fence_note_sync(struct radeon_fence *fence, int dst_ring)
 {
 	struct radeon_fence_driver *dst, *src;
@@ -546,6 +849,25 @@ void radeon_fence_note_sync(struct radeon_fence *fence, int dst_ring)
 	}
 }
 
+/**
+ * radeon_fence_driver_start_ring - make the fence driver
+ * ready for use on the requested ring.
+ *
+ * @rdev: radeon device pointer
+ * @ring: ring index to start the fence driver on
+ *
+ * Make the fence driver ready for processing (all asics).
+ * Not all asics have all rings, so each asic will only
+ * start the fence driver on the rings it has.
+ * Returns 0 for success, errors for failure.
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 int radeon_fence_driver_start_ring(struct radeon_device *rdev, int ring)
 {
 	uint64_t index;
@@ -574,6 +896,23 @@ int radeon_fence_driver_start_ring(struct radeon_device *rdev, int ring)
 	return 0;
 }
 
+/**
+ * radeon_fence_driver_init_ring - init the fence driver
+ * for the requested ring.
+ *
+ * @rdev: radeon device pointer
+ * @ring: ring index to start the fence driver on
+ *
+ * Init the fence driver for the requested ring (all asics).
+ * Helper function for radeon_fence_driver_init().
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 static void radeon_fence_driver_init_ring(struct radeon_device *rdev, int ring)
 {
 	int i;
@@ -588,6 +927,25 @@ static void radeon_fence_driver_init_ring(struct radeon_device *rdev, int ring)
 	rdev->fence_drv[ring].initialized = false;
 }
 
+/**
+ * radeon_fence_driver_init - init the fence driver
+ * for all possible rings.
+ *
+ * @rdev: radeon device pointer
+ *
+ * Init the fence driver for all possible rings (all asics).
+ * Not all asics have all rings, so each asic will only
+ * start the fence driver on the rings it has using
+ * radeon_fence_driver_start_ring().
+ * Returns 0 for success.
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 int radeon_fence_driver_init(struct radeon_device *rdev)
 {
 	int ring;
@@ -602,6 +960,21 @@ int radeon_fence_driver_init(struct radeon_device *rdev)
 	return 0;
 }
 
+/**
+ * radeon_fence_driver_fini - tear down the fence driver
+ * for all possible rings.
+ *
+ * @rdev: radeon device pointer
+ *
+ * Tear down the fence driver for all possible rings (all asics).
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
 void radeon_fence_driver_fini(struct radeon_device *rdev)
 {
 	int ring;
-- 
1.7.7.5

Re: [PATCH 05/10] drm/radeon: document radeon_fence.c

[Christian König]

Some minor comments spread over the whole file, see below:

On 29.06.2012 16:28, alexdeucher@gmail.com wrote:
> From: Alex Deucher <alexander.deucher@amd.com>
>
> Adds documentation to most of the functions in
> radeon_fence.c
>
> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
> ---
>   drivers/gpu/drm/radeon/radeon_fence.c |  373 +++++++++++++++++++++++++++++++++
>   1 files changed, 373 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_fence.c b/drivers/gpu/drm/radeon/radeon_fence.c
> index 67f6fa9..604352e 100644
> --- a/drivers/gpu/drm/radeon/radeon_fence.c
> +++ b/drivers/gpu/drm/radeon/radeon_fence.c
> @@ -40,6 +40,22 @@
>   #include "radeon.h"
>   #include "radeon_trace.h"
>   
> +/**
> + * radeon_fence_write - write a fence value
> + *
> + * @rdev: radeon_device pointer
> + * @seq: sequence number to write
> + * @ring: ring index the fence is associated with
> + *
> + * Writes a fence value to memory or a scratch register (all asics).
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
We should not repeat the description what a fence is for every function, 
instead a general comment over the whole file should be better. Also I 
would only mention the "all asics" stuff just once in the header of the 
file.

> + */
>   static void radeon_fence_write(struct radeon_device *rdev, u32 seq, int ring)
>   {
>   	if (rdev->wb.enabled) {
> @@ -49,6 +65,22 @@ static void radeon_fence_write(struct radeon_device *rdev, u32 seq, int ring)
>   	}
>   }
>   
> +/**
> + * radeon_fence_read - read a fence value
> + *
> + * @rdev: radeon_device pointer
> + * @ring: ring index the fence is associated with
> + *
> + * Reads a fence value from memory or a scratch register (all asics).
> + * Returns the value of the fence read from memory or register.
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */
>   static u32 radeon_fence_read(struct radeon_device *rdev, int ring)
>   {
>   	u32 seq = 0;
> @@ -61,6 +93,23 @@ static u32 radeon_fence_read(struct radeon_device *rdev, int ring)
>   	return seq;
>   }
>   
> +/**
> + * radeon_fence_emit - emit a fence on the requested ring
> + *
> + * @rdev: radeon_device pointer
> + * @fence: radeon fence object
> + * @ring: ring index the fence is associated with
> + *
> + * Emits a fence command on the requested ring (all asics).
> + * Returns 0 on success, -ENOMEM on failure.
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */
>   int radeon_fence_emit(struct radeon_device *rdev,
>   		      struct radeon_fence **fence,
>   		      int ring)
> @@ -79,6 +128,22 @@ int radeon_fence_emit(struct radeon_device *rdev,
>   	return 0;
>   }
>   
> +/**
> + * radeon_fence_process - process a fence
> + *
> + * @rdev: radeon_device pointer
> + * @ring: ring index the fence is associated with
> + *
> + * Checks the current fence value and wakes the fence queue
> + * if the sequence number has increased (all asics).
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */
>   void radeon_fence_process(struct radeon_device *rdev, int ring)
>   {
>   	uint64_t seq, last_seq;
> @@ -139,6 +204,20 @@ void radeon_fence_process(struct radeon_device *rdev, int ring)
>   	}
>   }
>   
> +/**
> + * radeon_fence_destroy - destroy a fence
> + *
> + * @kref: fence kref
> + *
> + * Frees the fence object (all asics).
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */
>   static void radeon_fence_destroy(struct kref *kref)
>   {
>   	struct radeon_fence *fence;
> @@ -147,6 +226,27 @@ static void radeon_fence_destroy(struct kref *kref)
>   	kfree(fence);
>   }
>   
> +/**
> + * radeon_fence_seq_signaled - check if a fence sequeuce number has signaled
> + *
> + * @rdev: radeon device pointer
> + * @seq: sequence number
> + * @ring: ring index the fence is associated with
> + *
> + * Check if the last singled fence sequnce number is >= the requested
> + * sequence number (all asics).
> + * Returns true if the fence has signaled (current fence value
> + * is >= requested value) or false if it has not (current fence
> + * value is < the requested value.  Helper function for
> + * radeon_fence_signaled().
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */
>   static bool radeon_fence_seq_signaled(struct radeon_device *rdev,
>   				      u64 seq, unsigned ring)
>   {
> @@ -161,6 +261,21 @@ static bool radeon_fence_seq_signaled(struct radeon_device *rdev,
>   	return false;
>   }
>   
> +/**
> + * radeon_fence_signaled - check if a fence has signaled
> + *
> + * @fence: radeon fence object
> + *
> + * Check if the requested fence has signaled (all asics).
> + * Returns true if the fence has signaled or false if it has not.
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */
>   bool radeon_fence_signaled(struct radeon_fence *fence)
>   {
>   	if (!fence) {
> @@ -176,6 +291,27 @@ bool radeon_fence_signaled(struct radeon_fence *fence)
>   	return false;
>   }
>   
> +/**
> + * radeon_fence_wait_seq - wait for a specific sequence number
> + *
> + * @rdev: radeon device pointer
> + * @target_seq: sequence number we want to wait for
> + * @ring: ring index the fence is associated with
> + * @intr: use interrupt or not
> + * @lock_ring: whether the ring should be locked or not
> + *
> + * Wait for the requested sequence number to be written (all asics).
> + * If @intr is true, use an interrupt to wake up.  Helper function
> + * for radeon_fence_wait(), et al.
The parameter description is incorrect. @intr tells the function to use 
an interruptible or not interruptible sleep, not if we use or not use 
the interrupt.

> + * Returns 0 if the sequence number has passed, error for all other cases.
We should better document possible EDEADLK error, and how to handle it.
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */

>   static int radeon_fence_wait_seq(struct radeon_device *rdev, u64 target_seq,
>   				 unsigned ring, bool intr, bool lock_ring)
>   {
> @@ -271,6 +407,23 @@ static int radeon_fence_wait_seq(struct radeon_device *rdev, u64 target_seq,
>   	return 0;
>   }
>   
> +/**
> + * radeon_fence_wait - wait for a fence to signal
> + *
> + * @fence: radeon fence object
> + * @intr: use interrupt or not
> + *
> + * Wait for the requested fence to signal (all asics).
> + * If @intr is true, use an interrupt to wake up.
Same as above, misleading description of the parameter.
> + * Returns 0 if the fence has passed, error for all other cases.
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */
>   int radeon_fence_wait(struct radeon_fence *fence, bool intr)
>   {
>   	int r;
> @@ -301,6 +454,26 @@ static bool radeon_fence_any_seq_signaled(struct radeon_device *rdev, u64 *seq)
>   	return false;
>   }
>   
> +/**
> + * radeon_fence_wait_any_seq - wait for a sequence number on any ring
> + *
> + * @rdev: radeon device pointer
> + * @target_seq: sequence number(s) we want to wait for
> + * @intr: use interrupt or not
> + *
> + * Wait for the requested sequence number(s) to be written by any ring
> + * (all asics).  Sequnce number array is indexed by ring id.
> + * If @intr is true, use an interrupt to wake up.  Helper function
> + * for radeon_fence_wait_any(), et al.
> + * Returns 0 if the sequence number has passed, error for all other cases.
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */
>   static int radeon_fence_wait_any_seq(struct radeon_device *rdev,
>   				     u64 *target_seq, bool intr)
>   {
> @@ -410,6 +583,25 @@ static int radeon_fence_wait_any_seq(struct radeon_device *rdev,
>   	return 0;
>   }
>   
> +/**
> + * radeon_fence_wait_any - wait for a fence to signal on any ring
> + *
> + * @rdev: radeon device pointer
> + * @fences: radeon fence object(s)
> + * @intr: use interrupt or not
> + *
> + * Wait for any requested fence to signal (all asics).  Fence
> + * array is indexed by ring id. If @intr is true, use an interrupt
> + * to wake up.  Used by the suballocator.
> + * Returns 0 if any fence has passed, error for all other cases.
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */
>   int radeon_fence_wait_any(struct radeon_device *rdev,
>   			  struct radeon_fence **fences,
>   			  bool intr)
> @@ -440,6 +632,22 @@ int radeon_fence_wait_any(struct radeon_device *rdev,
>   	return 0;
>   }
>   
> +/**
> + * radeon_fence_wait_next_locked - wait for the next fence to signal
> + *
> + * @rdev: radeon device pointer
> + * @ring: ring index the fence is associated with
> + *
> + * Wait for the next fence on the requested ring to signal (all asics).
> + * Returns 0 if the next fence has passed, error for all other cases.
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */
>   int radeon_fence_wait_next_locked(struct radeon_device *rdev, int ring)
>   {
>   	uint64_t seq;
> @@ -457,6 +665,22 @@ int radeon_fence_wait_next_locked(struct radeon_device *rdev, int ring)
>   	return radeon_fence_wait_seq(rdev, seq, ring, false, false);
>   }
>   
> +/**
> + * radeon_fence_wait_empty_locked - wait for all fences to signal
> + *
> + * @rdev: radeon device pointer
> + * @ring: ring index the fence is associated with
> + *
> + * Wait for all fences on the requested ring to signal (all asics).
> + * Returns 0 if the fences have passed, error for all other cases.
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */
>   int radeon_fence_wait_empty_locked(struct radeon_device *rdev, int ring)
>   {
>   	/* We are not protected by ring lock when reading current seq
> @@ -468,12 +692,41 @@ int radeon_fence_wait_empty_locked(struct radeon_device *rdev, int ring)
>   				     ring, false, false);
>   }
>   
> +/**
> + * radeon_fence_ref - take a ref on a fence
> + *
> + * @fence: radeon fence object
> + *
> + * Take a reference on a fence (all asics).
> + * Returns the fence.
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */
>   struct radeon_fence *radeon_fence_ref(struct radeon_fence *fence)
>   {
>   	kref_get(&fence->kref);
>   	return fence;
>   }
>   
> +/**
> + * radeon_fence_unref - remove a ref on a fence
> + *
> + * @fence: radeon fence object
> + *
> + * Remove a reference on a fence (all asics).
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */
>   void radeon_fence_unref(struct radeon_fence **fence)
>   {
>   	struct radeon_fence *tmp = *fence;
> @@ -484,6 +737,22 @@ void radeon_fence_unref(struct radeon_fence **fence)
>   	}
>   }
>   
> +/**
> + * radeon_fence_count_emitted - get the count of emitted fences
> + *
> + * @rdev: radeon device pointer
> + * @ring: ring index the fence is associated with
> + *
> + * Get the number of fences emitted on the requested ring (all asics).
> + * Returns the number of emitted fences on the ring.
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */
>   unsigned radeon_fence_count_emitted(struct radeon_device *rdev, int ring)
>   {
>   	uint64_t emitted;
> @@ -501,6 +770,24 @@ unsigned radeon_fence_count_emitted(struct radeon_device *rdev, int ring)
>   	return (unsigned)emitted;
>   }
>   
> +/**
> + * radeon_fence_need_sync - do we need a semaphore
> + *
> + * @fence: radeon fence object
> + * @dst_ring: which ring to check against
> + *
> + * Check if the fence needs to be synced against another ring
> + * (all asics).  If so, we need to emit a semaphore.
> + * Returns true if we need to sync with another ring, false if
> + * not.
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */
>   bool radeon_fence_need_sync(struct radeon_fence *fence, int dst_ring)
>   {
>   	struct radeon_fence_driver *fdrv;
> @@ -522,6 +809,22 @@ bool radeon_fence_need_sync(struct radeon_fence *fence, int dst_ring)
>   	return true;
>   }
>   
> +/**
> + * radeon_fence_note_sync - record the sync point
> + *
> + * @fence: radeon fence object
> + * @dst_ring: which ring to check against
> + *
> + * Note the sequence number at which point the fence will
> + * be synced with the requested ring (all asics).
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */
>   void radeon_fence_note_sync(struct radeon_fence *fence, int dst_ring)
>   {
>   	struct radeon_fence_driver *dst, *src;
> @@ -546,6 +849,25 @@ void radeon_fence_note_sync(struct radeon_fence *fence, int dst_ring)
>   	}
>   }
>   
> +/**
> + * radeon_fence_driver_start_ring - make the fence driver
> + * ready for use on the requested ring.
> + *
> + * @rdev: radeon device pointer
> + * @ring: ring index to start the fence driver on
> + *
> + * Make the fence driver ready for processing (all asics).
> + * Not all asics have all rings, so each asic will only
> + * start the fence driver on the rings it has.
> + * Returns 0 for success, errors for failure.
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */
>   int radeon_fence_driver_start_ring(struct radeon_device *rdev, int ring)
>   {
>   	uint64_t index;
> @@ -574,6 +896,23 @@ int radeon_fence_driver_start_ring(struct radeon_device *rdev, int ring)
>   	return 0;
>   }
>   
> +/**
> + * radeon_fence_driver_init_ring - init the fence driver
> + * for the requested ring.
> + *
> + * @rdev: radeon device pointer
> + * @ring: ring index to start the fence driver on
> + *
> + * Init the fence driver for the requested ring (all asics).
> + * Helper function for radeon_fence_driver_init().
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */
>   static void radeon_fence_driver_init_ring(struct radeon_device *rdev, int ring)
>   {
>   	int i;
> @@ -588,6 +927,25 @@ static void radeon_fence_driver_init_ring(struct radeon_device *rdev, int ring)
>   	rdev->fence_drv[ring].initialized = false;
>   }
>   
> +/**
> + * radeon_fence_driver_init - init the fence driver
> + * for all possible rings.
> + *
> + * @rdev: radeon device pointer
> + *
> + * Init the fence driver for all possible rings (all asics).
> + * Not all asics have all rings, so each asic will only
> + * start the fence driver on the rings it has using
> + * radeon_fence_driver_start_ring().
> + * Returns 0 for success.
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */
>   int radeon_fence_driver_init(struct radeon_device *rdev)
>   {
>   	int ring;
> @@ -602,6 +960,21 @@ int radeon_fence_driver_init(struct radeon_device *rdev)
>   	return 0;
>   }
>   
> +/**
> + * radeon_fence_driver_fini - tear down the fence driver
> + * for all possible rings.
> + *
> + * @rdev: radeon device pointer
> + *
> + * Tear down the fence driver for all possible rings (all asics).
> + * Fences mark an event in the GPUs pipeline and are used
> + * for GPU/CPU synchronization.  When the fence is written,
> + * it is expected that all buffers associated with that fence
> + * are no longer in use by the associated ring on the GPU and
> + * that the the relevant GPU caches have been flushed.  Whether
> + * we use a scratch register or memory location depends on the asic
> + * and whether writeback is enabled.
> + */
>   void radeon_fence_driver_fini(struct radeon_device *rdev)
>   {
>   	int ring;

[PATCH 06/10] drm/radeon: document radeon_ring.c

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

Adds documentation to most of the functions in
radeon_ring.c

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/radeon_ring.c |  374 +++++++++++++++++++++++++++++++++-
 1 files changed, 373 insertions(+), 1 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_ring.c b/drivers/gpu/drm/radeon/radeon_ring.c
index 0826e77..2a0febf 100644
--- a/drivers/gpu/drm/radeon/radeon_ring.c
+++ b/drivers/gpu/drm/radeon/radeon_ring.c
@@ -39,6 +39,24 @@
  */
 int radeon_debugfs_sa_init(struct radeon_device *rdev);
 
+/**
+ * radeon_ib_get - request an IB (Indirect Buffer)
+ *
+ * @rdev: radeon_device pointer
+ * @ring: ring index the IB is associated with
+ * @ib: IB object returned
+ * @size: requested IB size
+ *
+ * Request an IB (all asics).  IBs are allocated using the
+ * suballocator.
+ * Returns 0 on success, error on failure.
+ * IBs (Indirect Buffers) and areas of GPU accessible memory where
+ * commands are stored.  You can put a pointer to the IB in the
+ * command ring and the hw will fetch the commands from the IB
+ * and execute them.  Generally userspace acceleration drivers
+ * produce command buffers which are send to the kernel and
+ * put in IBs for execution by the requested ring.
+ */
 int radeon_ib_get(struct radeon_device *rdev, int ring,
 		  struct radeon_ib *ib, unsigned size)
 {
@@ -67,6 +85,20 @@ int radeon_ib_get(struct radeon_device *rdev, int ring,
 	return 0;
 }
 
+/**
+ * radeon_ib_free - free an IB (Indirect Buffer)
+ *
+ * @rdev: radeon_device pointer
+ * @ib: IB object to free
+ *
+ * Free an IB (all asics).
+ * IBs (Indirect Buffers) and areas of GPU accessible memory where
+ * commands are stored.  You can put a pointer to the IB in the
+ * command ring and the hw will fetch the commands from the IB
+ * and execute them.  Generally userspace acceleration drivers
+ * produce command buffers which are send to the kernel and
+ * put in IBs for execution by the requested ring.
+ */
 void radeon_ib_free(struct radeon_device *rdev, struct radeon_ib *ib)
 {
 	radeon_semaphore_free(rdev, &ib->semaphore, ib->fence);
@@ -74,6 +106,21 @@ void radeon_ib_free(struct radeon_device *rdev, struct radeon_ib *ib)
 	radeon_fence_unref(&ib->fence);
 }
 
+/**
+ * radeon_ib_schedule - schedule an IB (Indirect Buffer) on the ring
+ *
+ * @rdev: radeon_device pointer
+ * @ib: IB object to schedule
+ *
+ * Schedule an IB on the associated ring (all asics).
+ * Returns 0 on success, error on failure.
+ * IBs (Indirect Buffers) and areas of GPU accessible memory where
+ * commands are stored.  You can put a pointer to the IB in the
+ * command ring and the hw will fetch the commands from the IB
+ * and execute them.  Generally userspace acceleration drivers
+ * produce command buffers which are send to the kernel and
+ * put in IBs for execution by the requested ring.
+ */
 int radeon_ib_schedule(struct radeon_device *rdev, struct radeon_ib *ib)
 {
 	struct radeon_ring *ring = &rdev->ring[ib->ring];
@@ -116,6 +163,21 @@ int radeon_ib_schedule(struct radeon_device *rdev, struct radeon_ib *ib)
 	return 0;
 }
 
+/**
+ * radeon_ib_pool_init - Init the IB (Indirect Buffer) pool
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Initialize the suballocator to manage a pool of memory
+ * for use as IBs (all asics).
+ * Returns 0 on success, error on failure.
+ * IBs (Indirect Buffers) and areas of GPU accessible memory where
+ * commands are stored.  You can put a pointer to the IB in the
+ * command ring and the hw will fetch the commands from the IB
+ * and execute them.  Generally userspace acceleration drivers
+ * produce command buffers which are send to the kernel and
+ * put in IBs for execution by the requested ring.
+ */
 int radeon_ib_pool_init(struct radeon_device *rdev)
 {
 	int r;
@@ -136,6 +198,20 @@ int radeon_ib_pool_init(struct radeon_device *rdev)
 	return 0;
 }
 
+/**
+ * radeon_ib_pool_fini - Free the IB (Indirect Buffer) pool
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Tear down the suballocator managing the pool of memory
+ * for use as IBs (all asics).
+ * IBs (Indirect Buffers) and areas of GPU accessible memory where
+ * commands are stored.  You can put a pointer to the IB in the
+ * command ring and the hw will fetch the commands from the IB
+ * and execute them.  Generally userspace acceleration drivers
+ * produce command buffers which are send to the kernel and
+ * put in IBs for execution by the requested ring.
+ */
 void radeon_ib_pool_fini(struct radeon_device *rdev)
 {
 	if (rdev->ib_pool_ready) {
@@ -144,16 +220,64 @@ void radeon_ib_pool_fini(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * radeon_ib_pool_start - Start the IB (Indirect Buffer) pool
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Start the suballocator that manages pool of memory
+ * used for IBs (all asics).  Used to start the IB pool on
+ * device startup and resume.
+ * Returns 0 on success, error on failure.
+ * IBs (Indirect Buffers) and areas of GPU accessible memory where
+ * commands are stored.  You can put a pointer to the IB in the
+ * command ring and the hw will fetch the commands from the IB
+ * and execute them.  Generally userspace acceleration drivers
+ * produce command buffers which are send to the kernel and
+ * put in IBs for execution by the requested ring.
+ */
 int radeon_ib_pool_start(struct radeon_device *rdev)
 {
 	return radeon_sa_bo_manager_start(rdev, &rdev->ring_tmp_bo);
 }
 
+/**
+ * radeon_ib_pool_suspend - Suspend the IB (Indirect Buffer) pool
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Stop the suballocator that manages the pool of memory
+ * used as IBs (all asics).  Used to stop the IB pool on
+ * device suspend.
+ * Returns 0 on success, error on failure.
+ * IBs (Indirect Buffers) and areas of GPU accessible memory where
+ * commands are stored.  You can put a pointer to the IB in the
+ * command ring and the hw will fetch the commands from the IB
+ * and execute them.  Generally userspace acceleration drivers
+ * produce command buffers which are send to the kernel and
+ * put in IBs for execution by the requested ring.
+ */
 int radeon_ib_pool_suspend(struct radeon_device *rdev)
 {
 	return radeon_sa_bo_manager_suspend(rdev, &rdev->ring_tmp_bo);
 }
 
+/**
+ * radeon_ib_ring_tests - Test IBs (Indirect Buffer) on all
+ * relevant rings
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Execute a test IB on the rings (all asics).  Used to test
+ * if IBs are working on the rings at device startup and resume.
+ * Returns 0 on success, error on failure.
+ * IBs (Indirect Buffers) and areas of GPU accessible memory where
+ * commands are stored.  You can put a pointer to the IB in the
+ * command ring and the hw will fetch the commands from the IB
+ * and execute them.  Generally userspace acceleration drivers
+ * produce command buffers which are send to the kernel and
+ * put in IBs for execution by the requested ring.
+ */
 int radeon_ib_ring_tests(struct radeon_device *rdev)
 {
 	unsigned i;
@@ -189,6 +313,24 @@ int radeon_ib_ring_tests(struct radeon_device *rdev)
  */
 int radeon_debugfs_ring_init(struct radeon_device *rdev, struct radeon_ring *ring);
 
+/**
+ * radeon_ring_write - write a value to the ring
+ *
+ * @ring: radeon_ring structure holding ring information
+ * @v: dword (dw) value to write
+ *
+ * Write a value to the requested ring buffer (all asics).
+ * Most engines on the GPU are fed via ring buffers.  Ring
+ * buffers are areas of GPU accessible memory that the host
+ * writes commands into and the GPU reads commands out of.
+ * There is a rptr (read pointer) that determines where the
+ * GPU is currently reading, and a wptr (write pointer)
+ * which determines where the host has written.  When the
+ * pointers are equal, the ring is idle.  When the host
+ * writes commands to the ring buffer, it increments the
+ * wptr.  The GPU then starts fetching commands and executes
+ * them until the pointers are equal again.
+ */
 void radeon_ring_write(struct radeon_ring *ring, uint32_t v)
 {
 #if DRM_DEBUG_CODE
@@ -202,6 +344,25 @@ void radeon_ring_write(struct radeon_ring *ring, uint32_t v)
 	ring->ring_free_dw--;
 }
 
+/**
+ * radeon_ring_index - look up the index of the requested ring
+ *
+ * @rdev: radeon_device pointer
+ * @ring: radeon_ring structure holding ring information
+ *
+ * Look up the index of the requested ring object (all asics).
+ * Returns the index of the requested ring object.
+ * Most engines on the GPU are fed via ring buffers.  Ring
+ * buffers are areas of GPU accessible memory that the host
+ * writes commands into and the GPU reads commands out of.
+ * There is a rptr (read pointer) that determines where the
+ * GPU is currently reading, and a wptr (write pointer)
+ * which determines where the host has written.  When the
+ * pointers are equal, the ring is idle.  When the host
+ * writes commands to the ring buffer, it increments the
+ * wptr.  The GPU then starts fetching commands and executes
+ * them until the pointers are equal again.
+ */
 int radeon_ring_index(struct radeon_device *rdev, struct radeon_ring *ring)
 {
 	/* r1xx-r5xx only has CP ring */
@@ -217,6 +378,24 @@ int radeon_ring_index(struct radeon_device *rdev, struct radeon_ring *ring)
 	return RADEON_RING_TYPE_GFX_INDEX;
 }
 
+/**
+ * radeon_ring_free_size - update the free size
+ *
+ * @rdev: radeon_device pointer
+ * @ring: radeon_ring structure holding ring information
+ *
+ * Update the free dw slots in the ring buffer (all asics).
+ * Most engines on the GPU are fed via ring buffers.  Ring
+ * buffers are areas of GPU accessible memory that the host
+ * writes commands into and the GPU reads commands out of.
+ * There is a rptr (read pointer) that determines where the
+ * GPU is currently reading, and a wptr (write pointer)
+ * which determines where the host has written.  When the
+ * pointers are equal, the ring is idle.  When the host
+ * writes commands to the ring buffer, it increments the
+ * wptr.  The GPU then starts fetching commands and executes
+ * them until the pointers are equal again.
+ */
 void radeon_ring_free_size(struct radeon_device *rdev, struct radeon_ring *ring)
 {
 	u32 rptr;
@@ -235,7 +414,26 @@ void radeon_ring_free_size(struct radeon_device *rdev, struct radeon_ring *ring)
 	}
 }
 
-
+/**
+ * radeon_ring_alloc - allocate space on the ring buffer
+ *
+ * @rdev: radeon_device pointer
+ * @ring: radeon_ring structure holding ring information
+ * @ndw: number of dwords to allocate in the ring buffer
+ *
+ * Allocate @ndw dwords in the ring buffer (all asics).
+ * Returns 0 on success, error on failure.
+ * Most engines on the GPU are fed via ring buffers.  Ring
+ * buffers are areas of GPU accessible memory that the host
+ * writes commands into and the GPU reads commands out of.
+ * There is a rptr (read pointer) that determines where the
+ * GPU is currently reading, and a wptr (write pointer)
+ * which determines where the host has written.  When the
+ * pointers are equal, the ring is idle.  When the host
+ * writes commands to the ring buffer, it increments the
+ * wptr.  The GPU then starts fetching commands and executes
+ * them until the pointers are equal again.
+ */
 int radeon_ring_alloc(struct radeon_device *rdev, struct radeon_ring *ring, unsigned ndw)
 {
 	int r;
@@ -257,6 +455,27 @@ int radeon_ring_alloc(struct radeon_device *rdev, struct radeon_ring *ring, unsi
 	return 0;
 }
 
+/**
+ * radeon_ring_lock - lock the ring and allocate space on it
+ *
+ * @rdev: radeon_device pointer
+ * @ring: radeon_ring structure holding ring information
+ * @ndw: number of dwords to allocate in the ring buffer
+ *
+ * Lock the ring and allocate @ndw dwords in the ring buffer
+ * (all asics).
+ * Returns 0 on success, error on failure.
+ * Most engines on the GPU are fed via ring buffers.  Ring
+ * buffers are areas of GPU accessible memory that the host
+ * writes commands into and the GPU reads commands out of.
+ * There is a rptr (read pointer) that determines where the
+ * GPU is currently reading, and a wptr (write pointer)
+ * which determines where the host has written.  When the
+ * pointers are equal, the ring is idle.  When the host
+ * writes commands to the ring buffer, it increments the
+ * wptr.  The GPU then starts fetching commands and executes
+ * them until the pointers are equal again.
+ */
 int radeon_ring_lock(struct radeon_device *rdev, struct radeon_ring *ring, unsigned ndw)
 {
 	int r;
@@ -270,6 +489,26 @@ int radeon_ring_lock(struct radeon_device *rdev, struct radeon_ring *ring, unsig
 	return 0;
 }
 
+/**
+ * radeon_ring_commit - tell the GPU to execute the new
+ * commands on the ring buffer
+ *
+ * @rdev: radeon_device pointer
+ * @ring: radeon_ring structure holding ring information
+ *
+ * Update the wptr (write pointer) to tell the GPU to
+ * execute new commands on the ring buffer (all asics).
+ * Most engines on the GPU are fed via ring buffers.  Ring
+ * buffers are areas of GPU accessible memory that the host
+ * writes commands into and the GPU reads commands out of.
+ * There is a rptr (read pointer) that determines where the
+ * GPU is currently reading, and a wptr (write pointer)
+ * which determines where the host has written.  When the
+ * pointers are equal, the ring is idle.  When the host
+ * writes commands to the ring buffer, it increments the
+ * wptr.  The GPU then starts fetching commands and executes
+ * them until the pointers are equal again.
+ */
 void radeon_ring_commit(struct radeon_device *rdev, struct radeon_ring *ring)
 {
 	unsigned count_dw_pad;
@@ -286,23 +525,95 @@ void radeon_ring_commit(struct radeon_device *rdev, struct radeon_ring *ring)
 	(void)RREG32(ring->wptr_reg);
 }
 
+/**
+ * radeon_ring_unlock_commit - tell the GPU to execute the new
+ * commands on the ring buffer and unlock it
+ *
+ * @rdev: radeon_device pointer
+ * @ring: radeon_ring structure holding ring information
+ *
+ * Call radeon_ring_commit() then unlock the ring (all asics).
+ * Most engines on the GPU are fed via ring buffers.  Ring
+ * buffers are areas of GPU accessible memory that the host
+ * writes commands into and the GPU reads commands out of.
+ * There is a rptr (read pointer) that determines where the
+ * GPU is currently reading, and a wptr (write pointer)
+ * which determines where the host has written.  When the
+ * pointers are equal, the ring is idle.  When the host
+ * writes commands to the ring buffer, it increments the
+ * wptr.  The GPU then starts fetching commands and executes
+ * them until the pointers are equal again.
+ */
 void radeon_ring_unlock_commit(struct radeon_device *rdev, struct radeon_ring *ring)
 {
 	radeon_ring_commit(rdev, ring);
 	mutex_unlock(&rdev->ring_lock);
 }
 
+/**
+ * radeon_ring_undo - reset the wptr
+ *
+ * @ring: radeon_ring structure holding ring information
+ *
+ * Reset the driver's copy of the wtpr (all asics).
+ * Most engines on the GPU are fed via ring buffers.  Ring
+ * buffers are areas of GPU accessible memory that the host
+ * writes commands into and the GPU reads commands out of.
+ * There is a rptr (read pointer) that determines where the
+ * GPU is currently reading, and a wptr (write pointer)
+ * which determines where the host has written.  When the
+ * pointers are equal, the ring is idle.  When the host
+ * writes commands to the ring buffer, it increments the
+ * wptr.  The GPU then starts fetching commands and executes
+ * them until the pointers are equal again.
+ */
 void radeon_ring_undo(struct radeon_ring *ring)
 {
 	ring->wptr = ring->wptr_old;
 }
 
+/**
+ * radeon_ring_unlock_undo - reset the wptr and unlock the ring
+ *
+ * @ring: radeon_ring structure holding ring information
+ *
+ * Call radeon_ring_undo() then unlock the ring (all asics).
+ * Most engines on the GPU are fed via ring buffers.  Ring
+ * buffers are areas of GPU accessible memory that the host
+ * writes commands into and the GPU reads commands out of.
+ * There is a rptr (read pointer) that determines where the
+ * GPU is currently reading, and a wptr (write pointer)
+ * which determines where the host has written.  When the
+ * pointers are equal, the ring is idle.  When the host
+ * writes commands to the ring buffer, it increments the
+ * wptr.  The GPU then starts fetching commands and executes
+ * them until the pointers are equal again.
+ */
 void radeon_ring_unlock_undo(struct radeon_device *rdev, struct radeon_ring *ring)
 {
 	radeon_ring_undo(ring);
 	mutex_unlock(&rdev->ring_lock);
 }
 
+/**
+ * radeon_ring_force_activity - add some nop packets to the ring
+ *
+ * @rdev: radeon_device pointer
+ * @ring: radeon_ring structure holding ring information
+ *
+ * Add some nop packets to the ring to force activity (all asics).
+ * Used for lockup detection to see if the rptr is advancing.
+ * Most engines on the GPU are fed via ring buffers.  Ring
+ * buffers are areas of GPU accessible memory that the host
+ * writes commands into and the GPU reads commands out of.
+ * There is a rptr (read pointer) that determines where the
+ * GPU is currently reading, and a wptr (write pointer)
+ * which determines where the host has written.  When the
+ * pointers are equal, the ring is idle.  When the host
+ * writes commands to the ring buffer, it increments the
+ * wptr.  The GPU then starts fetching commands and executes
+ * them until the pointers are equal again.
+ */
 void radeon_ring_force_activity(struct radeon_device *rdev, struct radeon_ring *ring)
 {
 	int r;
@@ -317,6 +628,23 @@ void radeon_ring_force_activity(struct radeon_device *rdev, struct radeon_ring *
 	}
 }
 
+/**
+ * radeon_ring_force_activity - update lockup variables
+ *
+ * @ring: radeon_ring structure holding ring information
+ *
+ * Update the last rptr value and timestamp (all asics).
+ * Most engines on the GPU are fed via ring buffers.  Ring
+ * buffers are areas of GPU accessible memory that the host
+ * writes commands into and the GPU reads commands out of.
+ * There is a rptr (read pointer) that determines where the
+ * GPU is currently reading, and a wptr (write pointer)
+ * which determines where the host has written.  When the
+ * pointers are equal, the ring is idle.  When the host
+ * writes commands to the ring buffer, it increments the
+ * wptr.  The GPU then starts fetching commands and executes
+ * them until the pointers are equal again.
+ */
 void radeon_ring_lockup_update(struct radeon_ring *ring)
 {
 	ring->last_rptr = ring->rptr;
@@ -370,6 +698,32 @@ bool radeon_ring_test_lockup(struct radeon_device *rdev, struct radeon_ring *rin
 	return false;
 }
 
+/**
+ * radeon_ring_init - init driver ring struct.
+ *
+ * @rdev: radeon_device pointer
+ * @ring: radeon_ring structure holding ring information
+ * @ring_size: size of the ring
+ * @rptr_offs: offset of the rptr writeback location in the WB buffer
+ * @rptr_reg: MMIO offset of the rptr register
+ * @wptr_reg: MMIO offset of the wptr register
+ * @ptr_reg_shift: bit offset of the rptr/wptr values
+ * @ptr_reg_mask: bit mask of the rptr/wptr values
+ * @nop: nop packet for this ring
+ *
+ * Initialize the driver information for the selected ring (all asics).
+ * Returns 0 on success, error on failure.
+ * Most engines on the GPU are fed via ring buffers.  Ring
+ * buffers are areas of GPU accessible memory that the host
+ * writes commands into and the GPU reads commands out of.
+ * There is a rptr (read pointer) that determines where the
+ * GPU is currently reading, and a wptr (write pointer)
+ * which determines where the host has written.  When the
+ * pointers are equal, the ring is idle.  When the host
+ * writes commands to the ring buffer, it increments the
+ * wptr.  The GPU then starts fetching commands and executes
+ * them until the pointers are equal again.
+ */
 int radeon_ring_init(struct radeon_device *rdev, struct radeon_ring *ring, unsigned ring_size,
 		     unsigned rptr_offs, unsigned rptr_reg, unsigned wptr_reg,
 		     u32 ptr_reg_shift, u32 ptr_reg_mask, u32 nop)
@@ -418,6 +772,24 @@ int radeon_ring_init(struct radeon_device *rdev, struct radeon_ring *ring, unsig
 	return 0;
 }
 
+/**
+ * radeon_ring_fini - tear down the driver ring struct.
+ *
+ * @rdev: radeon_device pointer
+ * @ring: radeon_ring structure holding ring information
+ *
+ * Tear down the driver information for the selected ring (all asics).
+ * Most engines on the GPU are fed via ring buffers.  Ring
+ * buffers are areas of GPU accessible memory that the host
+ * writes commands into and the GPU reads commands out of.
+ * There is a rptr (read pointer) that determines where the
+ * GPU is currently reading, and a wptr (write pointer)
+ * which determines where the host has written.  When the
+ * pointers are equal, the ring is idle.  When the host
+ * writes commands to the ring buffer, it increments the
+ * wptr.  The GPU then starts fetching commands and executes
+ * them until the pointers are equal again.
+ */
 void radeon_ring_fini(struct radeon_device *rdev, struct radeon_ring *ring)
 {
 	int r;
-- 
1.7.7.5

[PATCH 07/10] drm/radeon: document non-VM functions in radeon_gart.c

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

Document the non-VM functions in radeon_gart.c

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/radeon_gart.c |  154 +++++++++++++++++++++++++++++++++-
 1 files changed, 151 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_gart.c b/drivers/gpu/drm/radeon/radeon_gart.c
index 8c44d1d..d9e29d5 100644
--- a/drivers/gpu/drm/radeon/radeon_gart.c
+++ b/drivers/gpu/drm/radeon/radeon_gart.c
@@ -33,6 +33,20 @@
 /*
  * Common GART table functions.
  */
+/**
+ * radeon_gart_table_ram_alloc - allocate system ram for gart page table
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Allocate system memory for GART page table
+ * (r1xx-r3xx, non-pcie r4xx, rs400).
+ * Returns 0 for success, -ENOMEM for failure.
+ * The GART (Graphics Aperture Remapping Table) is an aperture
+ * in the GPU's address space.  System pages can be mapped into
+ * the aperture and look like contiguous pages from the GPU's
+ * perspective.  A page table maps the pages in the aperture
+ * to the actual backing pages in system memory.
+ */
 int radeon_gart_table_ram_alloc(struct radeon_device *rdev)
 {
 	void *ptr;
@@ -54,6 +68,19 @@ int radeon_gart_table_ram_alloc(struct radeon_device *rdev)
 	return 0;
 }
 
+/**
+ * radeon_gart_table_ram_free - free system ram for gart page table
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Free system memory for GART page table
+ * (r1xx-r3xx, non-pcie r4xx, rs400).
+ * The GART (Graphics Aperture Remapping Table) is an aperture
+ * in the GPU's address space.  System pages can be mapped into
+ * the aperture and look like contiguous pages from the GPU's
+ * perspective.  A page table maps the pages in the aperture
+ * to the actual backing pages in system memory.
+ */
 void radeon_gart_table_ram_free(struct radeon_device *rdev)
 {
 	if (rdev->gart.ptr == NULL) {
@@ -73,6 +100,20 @@ void radeon_gart_table_ram_free(struct radeon_device *rdev)
 	rdev->gart.table_addr = 0;
 }
 
+/**
+ * radeon_gart_table_vram_alloc - allocate vram for gart page table
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Allocate video memory for GART page table
+ * (pcie r4xx, r5xx+).
+ * Returns 0 for success, error for failure.
+ * The GART (Graphics Aperture Remapping Table) is an aperture
+ * in the GPU's address space.  System pages can be mapped into
+ * the aperture and look like contiguous pages from the GPU's
+ * perspective.  A page table maps the pages in the aperture
+ * to the actual backing pages in system memory.
+ */
 int radeon_gart_table_vram_alloc(struct radeon_device *rdev)
 {
 	int r;
@@ -88,6 +129,20 @@ int radeon_gart_table_vram_alloc(struct radeon_device *rdev)
 	return 0;
 }
 
+/**
+ * radeon_gart_table_vram_pin - pin gart page table in vram
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Pin the GART page table in vram so it will not be moved
+ * by the memory manager (pcie r4xx, r5xx+).
+ * Returns 0 for success, error for failure.
+ * The GART (Graphics Aperture Remapping Table) is an aperture
+ * in the GPU's address space.  System pages can be mapped into
+ * the aperture and look like contiguous pages from the GPU's
+ * perspective.  A page table maps the pages in the aperture
+ * to the actual backing pages in system memory.
+ */
 int radeon_gart_table_vram_pin(struct radeon_device *rdev)
 {
 	uint64_t gpu_addr;
@@ -110,6 +165,18 @@ int radeon_gart_table_vram_pin(struct radeon_device *rdev)
 	return r;
 }
 
+/**
+ * radeon_gart_table_vram_unpin - unpin gart page table in vram
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Unpin the GART page table in vram (pcie r4xx, r5xx+).
+ * The GART (Graphics Aperture Remapping Table) is an aperture
+ * in the GPU's address space.  System pages can be mapped into
+ * the aperture and look like contiguous pages from the GPU's
+ * perspective.  A page table maps the pages in the aperture
+ * to the actual backing pages in system memory.
+ */
 void radeon_gart_table_vram_unpin(struct radeon_device *rdev)
 {
 	int r;
@@ -126,6 +193,19 @@ void radeon_gart_table_vram_unpin(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * radeon_gart_table_vram_free - free gart page table vram
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Free the video memory used for the GART page table
+ * (pcie r4xx, r5xx+).
+ * The GART (Graphics Aperture Remapping Table) is an aperture
+ * in the GPU's address space.  System pages can be mapped into
+ * the aperture and look like contiguous pages from the GPU's
+ * perspective.  A page table maps the pages in the aperture
+ * to the actual backing pages in system memory.
+ */
 void radeon_gart_table_vram_free(struct radeon_device *rdev)
 {
 	if (rdev->gart.robj == NULL) {
@@ -135,12 +215,24 @@ void radeon_gart_table_vram_free(struct radeon_device *rdev)
 	radeon_bo_unref(&rdev->gart.robj);
 }
 
-
-
-
 /*
  * Common gart functions.
  */
+/**
+ * radeon_gart_unbind - unbind pages from the gart page table
+ *
+ * @rdev: radeon_device pointer
+ * @offset: offset into the GPU's gart aperture
+ * @pages: number of pages to unbind
+ *
+ * Unbinds the requested pages from the gart page table and
+ * replaces them with the dummy page (all asics).
+ * The GART (Graphics Aperture Remapping Table) is an aperture
+ * in the GPU's address space.  System pages can be mapped into
+ * the aperture and look like contiguous pages from the GPU's
+ * perspective.  A page table maps the pages in the aperture
+ * to the actual backing pages in system memory.
+ */
 void radeon_gart_unbind(struct radeon_device *rdev, unsigned offset,
 			int pages)
 {
@@ -172,6 +264,24 @@ void radeon_gart_unbind(struct radeon_device *rdev, unsigned offset,
 	radeon_gart_tlb_flush(rdev);
 }
 
+/**
+ * radeon_gart_bind - bind pages into the gart page table
+ *
+ * @rdev: radeon_device pointer
+ * @offset: offset into the GPU's gart aperture
+ * @pages: number of pages to bind
+ * @pagelist: pages to bind
+ * @dma_addr: DMA addresses of pages
+ *
+ * Binds the requested pages to the gart page table
+ * (all asics).
+ * Returns 0 for success, -EINVAL for failure.
+ * The GART (Graphics Aperture Remapping Table) is an aperture
+ * in the GPU's address space.  System pages can be mapped into
+ * the aperture and look like contiguous pages from the GPU's
+ * perspective.  A page table maps the pages in the aperture
+ * to the actual backing pages in system memory.
+ */
 int radeon_gart_bind(struct radeon_device *rdev, unsigned offset,
 		     int pages, struct page **pagelist, dma_addr_t *dma_addr)
 {
@@ -203,6 +313,19 @@ int radeon_gart_bind(struct radeon_device *rdev, unsigned offset,
 	return 0;
 }
 
+/**
+ * radeon_gart_restore - bind all pages in the gart page table
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Binds all pages in the gart page table (all asics).
+ * Used to rebuild the gart table on device startup or resume.
+ * The GART (Graphics Aperture Remapping Table) is an aperture
+ * in the GPU's address space.  System pages can be mapped into
+ * the aperture and look like contiguous pages from the GPU's
+ * perspective.  A page table maps the pages in the aperture
+ * to the actual backing pages in system memory.
+ */
 void radeon_gart_restore(struct radeon_device *rdev)
 {
 	int i, j, t;
@@ -222,6 +345,19 @@ void radeon_gart_restore(struct radeon_device *rdev)
 	radeon_gart_tlb_flush(rdev);
 }
 
+/**
+ * radeon_gart_init - init the driver info for managing the gart
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Allocate the dummy page and init the gart driver info (all asics).
+ * Returns 0 for success, error for failure.
+ * The GART (Graphics Aperture Remapping Table) is an aperture
+ * in the GPU's address space.  System pages can be mapped into
+ * the aperture and look like contiguous pages from the GPU's
+ * perspective.  A page table maps the pages in the aperture
+ * to the actual backing pages in system memory.
+ */
 int radeon_gart_init(struct radeon_device *rdev)
 {
 	int r, i;
@@ -262,6 +398,18 @@ int radeon_gart_init(struct radeon_device *rdev)
 	return 0;
 }
 
+/**
+ * radeon_gart_fini - tear down the driver info for managing the gart
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Tear down the gart driver info and free the dummy page (all asics).
+ * The GART (Graphics Aperture Remapping Table) is an aperture
+ * in the GPU's address space.  System pages can be mapped into
+ * the aperture and look like contiguous pages from the GPU's
+ * perspective.  A page table maps the pages in the aperture
+ * to the actual backing pages in system memory.
+ */
 void radeon_gart_fini(struct radeon_device *rdev)
 {
 	if (rdev->gart.pages && rdev->gart.pages_addr && rdev->gart.ready) {
-- 
1.7.7.5

[PATCH 08/10] drm/radeon: document VM functions in radeon_gart.c

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

Document the VM functions in radeon_gart.c

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/radeon_gart.c |  237 ++++++++++++++++++++++++++++++++++
 1 files changed, 237 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_gart.c b/drivers/gpu/drm/radeon/radeon_gart.c
index d9e29d5..c37b501 100644
--- a/drivers/gpu/drm/radeon/radeon_gart.c
+++ b/drivers/gpu/drm/radeon/radeon_gart.c
@@ -430,6 +430,21 @@ void radeon_gart_fini(struct radeon_device *rdev)
  *
  * TODO bind a default page at vm initialization for default address
  */
+/**
+ * radeon_vm_manager_init - init the vm manager
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Init the vm manager (cayman+).
+ * Returns 0 for success, error for failure.
+ * GPUVM is similar to the legacy gart on older asics, however
+ * rather than there being a single global gart table
+ * for the entire GPU, there are multiple VM page tables active
+ * at any given time.  The VM page tables can contain a mix
+ * vram pages and system memory pages and system memory pages
+ * can be mapped as snooped (cached system pages) or unsnooped
+ * (uncached system pages).
+ */
 int radeon_vm_manager_init(struct radeon_device *rdev)
 {
 	int r;
@@ -455,6 +470,23 @@ int radeon_vm_manager_init(struct radeon_device *rdev)
 }
 
 /* global mutex must be lock */
+/**
+ * radeon_vm_unbind_locked - unbind a specific vm
+ *
+ * @rdev: radeon_device pointer
+ * @vm: vm to unbind
+ *
+ * Unbind the requested vm (cayman+).
+ * Wait for use of the VM to finish, then unbind the page table,
+ * and free the page table memory.
+ * GPUVM is similar to the legacy gart on older asics, however
+ * rather than there being a single global gart table
+ * for the entire GPU, there are multiple VM page tables active
+ * at any given time.  The VM page tables can contain a mix
+ * vram pages and system memory pages and system memory pages
+ * can be mapped as snooped (cached system pages) or unsnooped
+ * (uncached system pages).
+ */
 static void radeon_vm_unbind_locked(struct radeon_device *rdev,
 				    struct radeon_vm *vm)
 {
@@ -483,6 +515,20 @@ static void radeon_vm_unbind_locked(struct radeon_device *rdev,
 	}
 }
 
+/**
+ * radeon_vm_manager_fini - tear down the vm manager
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Tear down the VM manager (cayman+).
+ * GPUVM is similar to the legacy gart on older asics, however
+ * rather than there being a single global gart table
+ * for the entire GPU, there are multiple VM page tables active
+ * at any given time.  The VM page tables can contain a mix
+ * vram pages and system memory pages and system memory pages
+ * can be mapped as snooped (cached system pages) or unsnooped
+ * (uncached system pages).
+ */
 void radeon_vm_manager_fini(struct radeon_device *rdev)
 {
 	if (rdev->vm_manager.sa_manager.bo == NULL)
@@ -493,6 +539,21 @@ void radeon_vm_manager_fini(struct radeon_device *rdev)
 	rdev->vm_manager.enabled = false;
 }
 
+/**
+ * radeon_vm_manager_start - start the vm manager
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Start the suballocator instance used for VM (cayman+).
+ * Returns 0 for success, error for failure.
+ * GPUVM is similar to the legacy gart on older asics, however
+ * rather than there being a single global gart table
+ * for the entire GPU, there are multiple VM page tables active
+ * at any given time.  The VM page tables can contain a mix
+ * vram pages and system memory pages and system memory pages
+ * can be mapped as snooped (cached system pages) or unsnooped
+ * (uncached system pages).
+ */
 int radeon_vm_manager_start(struct radeon_device *rdev)
 {
 	if (rdev->vm_manager.sa_manager.bo == NULL) {
@@ -501,6 +562,22 @@ int radeon_vm_manager_start(struct radeon_device *rdev)
 	return radeon_sa_bo_manager_start(rdev, &rdev->vm_manager.sa_manager);
 }
 
+/**
+ * radeon_vm_manager_suspend - suspend the vm manager
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Unbind all the VM page tables and suspend the suballocator
+ * instance used for VM (cayman+).
+ * Returns 0 for success, error for failure.
+ * GPUVM is similar to the legacy gart on older asics, however
+ * rather than there being a single global gart table
+ * for the entire GPU, there are multiple VM page tables active
+ * at any given time.  The VM page tables can contain a mix
+ * vram pages and system memory pages and system memory pages
+ * can be mapped as snooped (cached system pages) or unsnooped
+ * (uncached system pages).
+ */
 int radeon_vm_manager_suspend(struct radeon_device *rdev)
 {
 	struct radeon_vm *vm, *tmp;
@@ -516,6 +593,21 @@ int radeon_vm_manager_suspend(struct radeon_device *rdev)
 }
 
 /* global mutex must be locked */
+/**
+ * radeon_vm_unbind - locked version of unbind
+ *
+ * @rdev: radeon_device pointer
+ * @vm: vm to unbind
+ *
+ * Locked version that wraps radeon_vm_unbind_locked (cayman+).
+ * GPUVM is similar to the legacy gart on older asics, however
+ * rather than there being a single global gart table
+ * for the entire GPU, there are multiple VM page tables active
+ * at any given time.  The VM page tables can contain a mix
+ * vram pages and system memory pages and system memory pages
+ * can be mapped as snooped (cached system pages) or unsnooped
+ * (uncached system pages).
+ */
 void radeon_vm_unbind(struct radeon_device *rdev, struct radeon_vm *vm)
 {
 	mutex_lock(&vm->mutex);
@@ -524,6 +616,25 @@ void radeon_vm_unbind(struct radeon_device *rdev, struct radeon_vm *vm)
 }
 
 /* global and local mutex must be locked */
+/**
+ * radeon_vm_bind - bind a page table to a VMID
+ *
+ * @rdev: radeon_device pointer
+ * @vm: vm to bind
+ *
+ * Bind the requested vm (cayman+).
+ * Suballocate memory for the page table, allocate a VMID
+ * and bind the page table to it, and finally start to populate
+ * the page table.
+ * Returns 0 for success, error for failure.
+ * GPUVM is similar to the legacy gart on older asics, however
+ * rather than there being a single global gart table
+ * for the entire GPU, there are multiple VM page tables active
+ * at any given time.  The VM page tables can contain a mix
+ * vram pages and system memory pages and system memory pages
+ * can be mapped as snooped (cached system pages) or unsnooped
+ * (uncached system pages).
+ */
 int radeon_vm_bind(struct radeon_device *rdev, struct radeon_vm *vm)
 {
 	struct radeon_vm *vm_evict;
@@ -586,6 +697,27 @@ retry_id:
 }
 
 /* object have to be reserved */
+/**
+ * radeon_vm_bo_add - add a bo to a specific vm
+ *
+ * @rdev: radeon_device pointer
+ * @vm: requested vm
+ * @bo: radeon buffer object
+ * @offset: requested offset of the buffer in the VM address space
+ * @flags: attributes of pages (read/write/valid/etc.)
+ *
+ * Add @bo into the requested vm (cayman+).
+ * Add @bo to the list of bos associated with the vm and validate
+ * the offset requested within the vm address space.
+ * Returns 0 for success, error for failure.
+ * GPUVM is similar to the legacy gart on older asics, however
+ * rather than there being a single global gart table
+ * for the entire GPU, there are multiple VM page tables active
+ * at any given time.  The VM page tables can contain a mix
+ * vram pages and system memory pages and system memory pages
+ * can be mapped as snooped (cached system pages) or unsnooped
+ * (uncached system pages).
+ */
 int radeon_vm_bo_add(struct radeon_device *rdev,
 		     struct radeon_vm *vm,
 		     struct radeon_bo *bo,
@@ -663,6 +795,24 @@ int radeon_vm_bo_add(struct radeon_device *rdev,
 	return 0;
 }
 
+/**
+ * radeon_vm_get_addr - get the physical address of the page
+ *
+ * @rdev: radeon_device pointer
+ * @mem: ttm mem
+ * @pfn: pfn
+ *
+ * Look up the physical address of the page that the pte resolves
+ * to (cayman+).
+ * Returns the physical address of the page.
+ * GPUVM is similar to the legacy gart on older asics, however
+ * rather than there being a single global gart table
+ * for the entire GPU, there are multiple VM page tables active
+ * at any given time.  The VM page tables can contain a mix
+ * vram pages and system memory pages and system memory pages
+ * can be mapped as snooped (cached system pages) or unsnooped
+ * (uncached system pages).
+ */
 static u64 radeon_vm_get_addr(struct radeon_device *rdev,
 			      struct ttm_mem_reg *mem,
 			      unsigned pfn)
@@ -692,6 +842,24 @@ static u64 radeon_vm_get_addr(struct radeon_device *rdev,
 }
 
 /* object have to be reserved & global and local mutex must be locked */
+/**
+ * radeon_vm_bo_update_pte - map a bo into the vm page table
+ *
+ * @rdev: radeon_device pointer
+ * @vm: requested vm
+ * @bo: radeon buffer object
+ * @mem: ttm mem
+ *
+ * Fill in the page table entries for @bo (cayman+).
+ * Returns 0 for success, -EINVAL for failure.
+ * GPUVM is similar to the legacy gart on older asics, however
+ * rather than there being a single global gart table
+ * for the entire GPU, there are multiple VM page tables active
+ * at any given time.  The VM page tables can contain a mix
+ * vram pages and system memory pages and system memory pages
+ * can be mapped as snooped (cached system pages) or unsnooped
+ * (uncached system pages).
+ */
 int radeon_vm_bo_update_pte(struct radeon_device *rdev,
 			    struct radeon_vm *vm,
 			    struct radeon_bo *bo,
@@ -740,6 +908,25 @@ int radeon_vm_bo_update_pte(struct radeon_device *rdev,
 }
 
 /* object have to be reserved */
+/**
+ * radeon_vm_bo_rmv - remove a bo to a specific vm
+ *
+ * @rdev: radeon_device pointer
+ * @vm: requested vm
+ * @bo: radeon buffer object
+ *
+ * Remove @bo from the requested vm (cayman+).
+ * Remove @bo from the list of bos associated with the vm and
+ * remove the ptes for @bo in the page table.
+ * Returns 0 for success.
+ * GPUVM is similar to the legacy gart on older asics, however
+ * rather than there being a single global gart table
+ * for the entire GPU, there are multiple VM page tables active
+ * at any given time.  The VM page tables can contain a mix
+ * vram pages and system memory pages and system memory pages
+ * can be mapped as snooped (cached system pages) or unsnooped
+ * (uncached system pages).
+ */
 int radeon_vm_bo_rmv(struct radeon_device *rdev,
 		     struct radeon_vm *vm,
 		     struct radeon_bo *bo)
@@ -762,6 +949,22 @@ int radeon_vm_bo_rmv(struct radeon_device *rdev,
 	return 0;
 }
 
+/**
+ * radeon_vm_bo_invalidate - mark the bo as invalid
+ *
+ * @rdev: radeon_device pointer
+ * @vm: requested vm
+ * @bo: radeon buffer object
+ *
+ * Mark @bo as invalid (cayman+).
+ * GPUVM is similar to the legacy gart on older asics, however
+ * rather than there being a single global gart table
+ * for the entire GPU, there are multiple VM page tables active
+ * at any given time.  The VM page tables can contain a mix
+ * vram pages and system memory pages and system memory pages
+ * can be mapped as snooped (cached system pages) or unsnooped
+ * (uncached system pages).
+ */
 void radeon_vm_bo_invalidate(struct radeon_device *rdev,
 			     struct radeon_bo *bo)
 {
@@ -773,6 +976,24 @@ void radeon_vm_bo_invalidate(struct radeon_device *rdev,
 	}
 }
 
+/**
+ * radeon_vm_init - initialize a vm instance
+ *
+ * @rdev: radeon_device pointer
+ * @vm: requested vm
+ *
+ * Init @vm (cayman+).
+ * Map the IB pool and any other shared objects into the VM
+ * by default as it's used by all VMs.
+ * Returns 0 for success, error for failure.
+ * GPUVM is similar to the legacy gart on older asics, however
+ * rather than there being a single global gart table
+ * for the entire GPU, there are multiple VM page tables active
+ * at any given time.  The VM page tables can contain a mix
+ * vram pages and system memory pages and system memory pages
+ * can be mapped as snooped (cached system pages) or unsnooped
+ * (uncached system pages).
+ */
 int radeon_vm_init(struct radeon_device *rdev, struct radeon_vm *vm)
 {
 	int r;
@@ -799,6 +1020,22 @@ int radeon_vm_init(struct radeon_device *rdev, struct radeon_vm *vm)
 	return r;
 }
 
+/**
+ * radeon_vm_init - tear down a vm instance
+ *
+ * @rdev: radeon_device pointer
+ * @vm: requested vm
+ *
+ * Tear down @vm (cayman+).
+ * Unbind the VM and remove all bos from the vm bo list
+ * GPUVM is similar to the legacy gart on older asics, however
+ * rather than there being a single global gart table
+ * for the entire GPU, there are multiple VM page tables active
+ * at any given time.  The VM page tables can contain a mix
+ * vram pages and system memory pages and system memory pages
+ * can be mapped as snooped (cached system pages) or unsnooped
+ * (uncached system pages).
+ */
 void radeon_vm_fini(struct radeon_device *rdev, struct radeon_vm *vm)
 {
 	struct radeon_bo_va *bo_va, *tmp;
-- 
1.7.7.5

[PATCH 09/10] drm/radeon: start to document the functions r100.c

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

Still a lot more to do.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/r100.c |  127 ++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 124 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.c
index d06c8dd..84477dc 100644
--- a/drivers/gpu/drm/radeon/r100.c
+++ b/drivers/gpu/drm/radeon/r100.c
@@ -65,6 +65,19 @@ MODULE_FIRMWARE(FIRMWARE_R520);
 
 #include "r100_track.h"
 
+/* This files gather functions specifics to:
+ * r100,rv100,rs100,rv200,rs200,r200,rv250,rs300,rv280
+ * and others in some cases.
+ */
+
+/**
+ * r100_wait_for_vblank - vblank wait asic callback.
+ *
+ * @rdev: radeon_device pointer
+ * @crtc: crtc to wait for vblank on
+ *
+ * Wait for vblank on the requested crtc (r1xx-r4xx).
+ */
 void r100_wait_for_vblank(struct radeon_device *rdev, int crtc)
 {
 	struct radeon_crtc *radeon_crtc = rdev->mode_info.crtcs[crtc];
@@ -99,22 +112,49 @@ void r100_wait_for_vblank(struct radeon_device *rdev, int crtc)
 	}
 }
 
-/* This files gather functions specifics to:
- * r100,rv100,rs100,rv200,rs200,r200,rv250,rs300,rv280
+/**
+ * r100_pre_page_flip - pre-pageflip callback.
+ *
+ * @rdev: radeon_device pointer
+ * @crtc: crtc to prepare for pageflip on
+ *
+ * Pre-pageflip callback (r1xx-r4xx).
+ * Enables the pageflip irq (vblank irq).
  */
-
 void r100_pre_page_flip(struct radeon_device *rdev, int crtc)
 {
 	/* enable the pflip int */
 	radeon_irq_kms_pflip_irq_get(rdev, crtc);
 }
 
+/**
+ * r100_post_page_flip - pos-pageflip callback.
+ *
+ * @rdev: radeon_device pointer
+ * @crtc: crtc to cleanup pageflip on
+ *
+ * Post-pageflip callback (r1xx-r4xx).
+ * Disables the pageflip irq (vblank irq).
+ */
 void r100_post_page_flip(struct radeon_device *rdev, int crtc)
 {
 	/* disable the pflip int */
 	radeon_irq_kms_pflip_irq_put(rdev, crtc);
 }
 
+/**
+ * r100_page_flip - pageflip callback.
+ *
+ * @rdev: radeon_device pointer
+ * @crtc_id: crtc to cleanup pageflip on
+ * @crtc_base: new address of the crtc (GPU MC address)
+ *
+ * Does the actual pageflip (r1xx-r4xx).
+ * During vblank we take the crtc lock and wait for the update_pending
+ * bit to go high, when it does, we release the lock, and allow the
+ * double buffered update to take place.
+ * Returns the current update pending status.
+ */
 u32 r100_page_flip(struct radeon_device *rdev, int crtc_id, u64 crtc_base)
 {
 	struct radeon_crtc *radeon_crtc = rdev->mode_info.crtcs[crtc_id];
@@ -141,6 +181,15 @@ u32 r100_page_flip(struct radeon_device *rdev, int crtc_id, u64 crtc_base)
 	return RREG32(RADEON_CRTC_OFFSET + radeon_crtc->crtc_offset) & RADEON_CRTC_OFFSET__GUI_TRIG_OFFSET;
 }
 
+/**
+ * r100_pm_get_dynpm_state - look up dynpm power state callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Look up the optimal power state based on the
+ * current state of the GPU (r1xx-r5xx).
+ * Used for dynpm only.
+ */
 void r100_pm_get_dynpm_state(struct radeon_device *rdev)
 {
 	int i;
@@ -223,6 +272,15 @@ void r100_pm_get_dynpm_state(struct radeon_device *rdev)
 		  pcie_lanes);
 }
 
+/**
+ * r100_pm_init_profile - Initialize power profiles callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Initialize the power states used in profile mode
+ * (r1xx-r3xx).
+ * Used for profile mode only.
+ */
 void r100_pm_init_profile(struct radeon_device *rdev)
 {
 	/* default */
@@ -262,6 +320,14 @@ void r100_pm_init_profile(struct radeon_device *rdev)
 	rdev->pm.profiles[PM_PROFILE_HIGH_MH_IDX].dpms_on_cm_idx = 0;
 }
 
+/**
+ * r100_pm_misc - set additional pm hw parameters callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Set non-clock parameters associated with a power state
+ * (voltage, pcie lanes, etc.) (r1xx-r4xx).
+ */
 void r100_pm_misc(struct radeon_device *rdev)
 {
 	int requested_index = rdev->pm.requested_power_state_index;
@@ -353,6 +419,13 @@ void r100_pm_misc(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * r100_pm_prepare - pre-power state change callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Prepare for a power state change (r1xx-r4xx).
+ */
 void r100_pm_prepare(struct radeon_device *rdev)
 {
 	struct drm_device *ddev = rdev->ddev;
@@ -377,6 +450,13 @@ void r100_pm_prepare(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * r100_pm_finish - post-power state change callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Clean up after a power state change (r1xx-r4xx).
+ */
 void r100_pm_finish(struct radeon_device *rdev)
 {
 	struct drm_device *ddev = rdev->ddev;
@@ -401,6 +481,14 @@ void r100_pm_finish(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * r100_gui_idle - gui idle callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Check of the GUI (2D/3D engines) are idle (r1xx-r5xx).
+ * Returns true if idle, false if not.
+ */
 bool r100_gui_idle(struct radeon_device *rdev)
 {
 	if (RREG32(RADEON_RBBM_STATUS) & RADEON_RBBM_ACTIVE)
@@ -410,6 +498,15 @@ bool r100_gui_idle(struct radeon_device *rdev)
 }
 
 /* hpd for digital panel detect/disconnect */
+/**
+ * r100_hpd_sense - hpd sense callback.
+ *
+ * @rdev: radeon_device pointer
+ * @hpd: hpd (hotplug detect) pin
+ *
+ * Checks if a digital monitor is connected (r1xx-r4xx).
+ * Returns true if connected, false if not connected.
+ */
 bool r100_hpd_sense(struct radeon_device *rdev, enum radeon_hpd_id hpd)
 {
 	bool connected = false;
@@ -429,6 +526,14 @@ bool r100_hpd_sense(struct radeon_device *rdev, enum radeon_hpd_id hpd)
 	return connected;
 }
 
+/**
+ * r100_hpd_set_polarity - hpd set polarity callback.
+ *
+ * @rdev: radeon_device pointer
+ * @hpd: hpd (hotplug detect) pin
+ *
+ * Set the polarity of the hpd pin (r1xx-r4xx).
+ */
 void r100_hpd_set_polarity(struct radeon_device *rdev,
 			   enum radeon_hpd_id hpd)
 {
@@ -457,6 +562,14 @@ void r100_hpd_set_polarity(struct radeon_device *rdev,
 	}
 }
 
+/**
+ * r100_hpd_init - hpd setup callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Setup the hpd pins used by the card (r1xx-r4xx).
+ * Set the polarity, and enable the hpd interrupts.
+ */
 void r100_hpd_init(struct radeon_device *rdev)
 {
 	struct drm_device *dev = rdev->ddev;
@@ -471,6 +584,14 @@ void r100_hpd_init(struct radeon_device *rdev)
 	radeon_irq_kms_enable_hpd(rdev, enable);
 }
 
+/**
+ * r100_hpd_fini - hpd tear down callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Tear down the hpd pins used by the card (r1xx-r4xx).
+ * Disable the hpd interrupts.
+ */
 void r100_hpd_fini(struct radeon_device *rdev)
 {
 	struct drm_device *dev = rdev->ddev;
-- 
1.7.7.5

[PATCH 10/10] drm/radeon: start to document evergreen.c

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

Still a lot to do.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/evergreen.c |  120 ++++++++++++++++++++++++++++++++++++
 1 files changed, 120 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index f716e08..0fc68a7 100644
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -99,6 +99,14 @@ void evergreen_fix_pci_max_read_req_size(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * dce4_wait_for_vblank - vblank wait asic callback.
+ *
+ * @rdev: radeon_device pointer
+ * @crtc: crtc to wait for vblank on
+ *
+ * Wait for vblank on the requested crtc (evergreen+).
+ */
 void dce4_wait_for_vblank(struct radeon_device *rdev, int crtc)
 {
 	struct radeon_crtc *radeon_crtc = rdev->mode_info.crtcs[crtc];
@@ -118,18 +126,49 @@ void dce4_wait_for_vblank(struct radeon_device *rdev, int crtc)
 	}
 }
 
+/**
+ * radeon_irq_kms_pflip_irq_get - pre-pageflip callback.
+ *
+ * @rdev: radeon_device pointer
+ * @crtc: crtc to prepare for pageflip on
+ *
+ * Pre-pageflip callback (evergreen+).
+ * Enables the pageflip irq (vblank irq).
+ */
 void evergreen_pre_page_flip(struct radeon_device *rdev, int crtc)
 {
 	/* enable the pflip int */
 	radeon_irq_kms_pflip_irq_get(rdev, crtc);
 }
 
+/**
+ * evergreen_post_page_flip - pos-pageflip callback.
+ *
+ * @rdev: radeon_device pointer
+ * @crtc: crtc to cleanup pageflip on
+ *
+ * Post-pageflip callback (evergreen+).
+ * Disables the pageflip irq (vblank irq).
+ */
 void evergreen_post_page_flip(struct radeon_device *rdev, int crtc)
 {
 	/* disable the pflip int */
 	radeon_irq_kms_pflip_irq_put(rdev, crtc);
 }
 
+/**
+ * evergreen_page_flip - pageflip callback.
+ *
+ * @rdev: radeon_device pointer
+ * @crtc_id: crtc to cleanup pageflip on
+ * @crtc_base: new address of the crtc (GPU MC address)
+ *
+ * Does the actual pageflip (evergreen+).
+ * During vblank we take the crtc lock and wait for the update_pending
+ * bit to go high, when it does, we release the lock, and allow the
+ * double buffered update to take place.
+ * Returns the current update pending status.
+ */
 u32 evergreen_page_flip(struct radeon_device *rdev, int crtc_id, u64 crtc_base)
 {
 	struct radeon_crtc *radeon_crtc = rdev->mode_info.crtcs[crtc_id];
@@ -214,6 +253,15 @@ int sumo_get_temp(struct radeon_device *rdev)
 	return actual_temp * 1000;
 }
 
+/**
+ * sumo_pm_init_profile - Initialize power profiles callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Initialize the power states used in profile mode
+ * (sumo, trinity, SI).
+ * Used for profile mode only.
+ */
 void sumo_pm_init_profile(struct radeon_device *rdev)
 {
 	int idx;
@@ -265,6 +313,14 @@ void sumo_pm_init_profile(struct radeon_device *rdev)
 		rdev->pm.power_state[idx].num_clock_modes - 1;
 }
 
+/**
+ * evergreen_pm_misc - set additional pm hw parameters callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Set non-clock parameters associated with a power state
+ * (voltage, etc.) (evergreen+).
+ */
 void evergreen_pm_misc(struct radeon_device *rdev)
 {
 	int req_ps_idx = rdev->pm.requested_power_state_index;
@@ -292,6 +348,13 @@ void evergreen_pm_misc(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * evergreen_pm_prepare - pre-power state change callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Prepare for a power state change (evergreen+).
+ */
 void evergreen_pm_prepare(struct radeon_device *rdev)
 {
 	struct drm_device *ddev = rdev->ddev;
@@ -310,6 +373,13 @@ void evergreen_pm_prepare(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * evergreen_pm_finish - post-power state change callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Clean up after a power state change (evergreen+).
+ */
 void evergreen_pm_finish(struct radeon_device *rdev)
 {
 	struct drm_device *ddev = rdev->ddev;
@@ -328,6 +398,15 @@ void evergreen_pm_finish(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * evergreen_hpd_sense - hpd sense callback.
+ *
+ * @rdev: radeon_device pointer
+ * @hpd: hpd (hotplug detect) pin
+ *
+ * Checks if a digital monitor is connected (evergreen+).
+ * Returns true if connected, false if not connected.
+ */
 bool evergreen_hpd_sense(struct radeon_device *rdev, enum radeon_hpd_id hpd)
 {
 	bool connected = false;
@@ -364,6 +443,14 @@ bool evergreen_hpd_sense(struct radeon_device *rdev, enum radeon_hpd_id hpd)
 	return connected;
 }
 
+/**
+ * evergreen_hpd_set_polarity - hpd set polarity callback.
+ *
+ * @rdev: radeon_device pointer
+ * @hpd: hpd (hotplug detect) pin
+ *
+ * Set the polarity of the hpd pin (evergreen+).
+ */
 void evergreen_hpd_set_polarity(struct radeon_device *rdev,
 				enum radeon_hpd_id hpd)
 {
@@ -424,6 +511,14 @@ void evergreen_hpd_set_polarity(struct radeon_device *rdev,
 	}
 }
 
+/**
+ * evergreen_hpd_init - hpd setup callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Setup the hpd pins used by the card (evergreen+).
+ * Enable the pin, set the polarity, and enable the hpd interrupts.
+ */
 void evergreen_hpd_init(struct radeon_device *rdev)
 {
 	struct drm_device *dev = rdev->ddev;
@@ -462,6 +557,14 @@ void evergreen_hpd_init(struct radeon_device *rdev)
 	radeon_irq_kms_enable_hpd(rdev, enabled);
 }
 
+/**
+ * evergreen_hpd_fini - hpd tear down callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Tear down the hpd pins used by the card (evergreen+).
+ * Disable the hpd interrupts.
+ */
 void evergreen_hpd_fini(struct radeon_device *rdev)
 {
 	struct drm_device *dev = rdev->ddev;
@@ -925,6 +1028,14 @@ static void evergreen_program_watermarks(struct radeon_device *rdev,
 
 }
 
+/**
+ * evergreen_bandwidth_update - update display watermarks callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Update the display watermarks based on the requested mode(s)
+ * (evergreen+).
+ */
 void evergreen_bandwidth_update(struct radeon_device *rdev)
 {
 	struct drm_display_mode *mode0 = NULL;
@@ -948,6 +1059,15 @@ void evergreen_bandwidth_update(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * evergreen_mc_wait_for_idle - wait for MC idle callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Wait for the MC (memory controller) to be idle.
+ * (evergreen+).
+ * Returns 0 if the MC is idle, -1 if not.
+ */
 int evergreen_mc_wait_for_idle(struct radeon_device *rdev)
 {
 	unsigned i;
-- 
1.7.7.5

Re: [PATCH 00/10] Start documenting the radeon drm better

[Christian König]

On 29.06.2012 16:28, alexdeucher@gmail.com wrote:
> From: Alex Deucher <alexander.deucher@amd.com>
>
> This is something I've been wanting to do for a while and
> I finally spent a little time getting a start on it.  There
> is still a lot to do and not all of my descriptions are great,
> but I think we can document the rest in bits and pieces. I
> also added a note about what asics the function is applicable
> to. I tried to start with the more common and complex code.
> I was thinking it would make sense to have an informal
> documentation policy something like the following:
> 1. If you edit an undocumented function, add documentation
> 2. If you edit a documented function and change how it works,
>     update the documentation
> 3. All new functions added should be documented
>
> Fulfulling all of these for stable fixes could pose problems
> so obviously there is some leeway.
>
> Thoughts?
Sounds like a good idea to me, but could we move the old and deprecated 
non KMS code into it's own subdirectory or something like that first?

Also for some files it might be a good idea to spread them into separate 
ones first, like the gart and vm and/or the ring and ib stuff.

Cheers,
Christian.

>
> Alex Deucher (10):
>    drm/radeon: document radeon_device.c
>    drm/radeon: document radeon_kms.c
>    drm/radeon: document radeon_irq_kms.c
>    drm/radeon: document radeon_asic.c
>    drm/radeon: document radeon_fence.c
>    drm/radeon: document radeon_ring.c
>    drm/radeon: document non-VM functions in radeon_gart.c
>    drm/radeon: document VM functions in radeon_gart.c
>    drm/radeon: start to document the functions r100.c
>    drm/radeon: start to document evergreen.c
>
>   drivers/gpu/drm/radeon/evergreen.c      |  120 ++++++++++
>   drivers/gpu/drm/radeon/r100.c           |  127 ++++++++++-
>   drivers/gpu/drm/radeon/radeon_asic.c    |   46 ++++
>   drivers/gpu/drm/radeon/radeon_device.c  |  344 +++++++++++++++++++++++++++-
>   drivers/gpu/drm/radeon/radeon_fence.c   |  373 +++++++++++++++++++++++++++++
>   drivers/gpu/drm/radeon/radeon_gart.c    |  391 ++++++++++++++++++++++++++++++-
>   drivers/gpu/drm/radeon/radeon_irq_kms.c |  150 ++++++++++++
>   drivers/gpu/drm/radeon/radeon_kms.c     |  126 ++++++++++
>   drivers/gpu/drm/radeon/radeon_ring.c    |  374 +++++++++++++++++++++++++++++-
>   9 files changed, 2041 insertions(+), 10 deletions(-)
>

Re: [PATCH 00/10] Start documenting the radeon drm better

[Alex Deucher]

On Fri, Jun 29, 2012 at 10:39 AM, Christian König
<deathsimple@vodafone.de> wrote:
> On 29.06.2012 16:28, alexdeucher@gmail.com wrote:
>>
>> From: Alex Deucher <alexander.deucher@amd.com>
>>
>> This is something I've been wanting to do for a while and
>> I finally spent a little time getting a start on it.  There
>> is still a lot to do and not all of my descriptions are great,
>> but I think we can document the rest in bits and pieces. I
>> also added a note about what asics the function is applicable
>> to. I tried to start with the more common and complex code.
>> I was thinking it would make sense to have an informal
>> documentation policy something like the following:
>> 1. If you edit an undocumented function, add documentation
>> 2. If you edit a documented function and change how it works,
>>    update the documentation
>> 3. All new functions added should be documented
>>
>> Fulfulling all of these for stable fixes could pose problems
>> so obviously there is some leeway.
>>
>> Thoughts?
>
> Sounds like a good idea to me, but could we move the old and deprecated non
> KMS code into it's own subdirectory or something like that first?

That would be nice.  Maybe add a new ums folder in radeon?

>
> Also for some files it might be a good idea to spread them into separate
> ones first, like the gart and vm and/or the ring and ib stuff.

Yeah, there is a lot of room of clean up.  r100.c could be split into
about 3 files to match newer asics.

Alex

>
> Cheers,
> Christian.
>
>
>>
>> Alex Deucher (10):
>>   drm/radeon: document radeon_device.c
>>   drm/radeon: document radeon_kms.c
>>   drm/radeon: document radeon_irq_kms.c
>>   drm/radeon: document radeon_asic.c
>>   drm/radeon: document radeon_fence.c
>>   drm/radeon: document radeon_ring.c
>>   drm/radeon: document non-VM functions in radeon_gart.c
>>   drm/radeon: document VM functions in radeon_gart.c
>>   drm/radeon: start to document the functions r100.c
>>   drm/radeon: start to document evergreen.c
>>
>>  drivers/gpu/drm/radeon/evergreen.c      |  120 ++++++++++
>>  drivers/gpu/drm/radeon/r100.c           |  127 ++++++++++-
>>  drivers/gpu/drm/radeon/radeon_asic.c    |   46 ++++
>>  drivers/gpu/drm/radeon/radeon_device.c  |  344
>> +++++++++++++++++++++++++++-
>>  drivers/gpu/drm/radeon/radeon_fence.c   |  373
>> +++++++++++++++++++++++++++++
>>  drivers/gpu/drm/radeon/radeon_gart.c    |  391
>> ++++++++++++++++++++++++++++++-
>>  drivers/gpu/drm/radeon/radeon_irq_kms.c |  150 ++++++++++++
>>  drivers/gpu/drm/radeon/radeon_kms.c     |  126 ++++++++++
>>  drivers/gpu/drm/radeon/radeon_ring.c    |  374
>> +++++++++++++++++++++++++++++-
>>  9 files changed, 2041 insertions(+), 10 deletions(-)
>>
>
>

Re: [PATCH 00/10] Start documenting the radeon drm better

[Tom Stellard]

On Fri, Jun 29, 2012 at 10:28:20AM -0400, alexdeucher@gmail.com wrote:
> From: Alex Deucher <alexander.deucher@amd.com>
> 
> This is something I've been wanting to do for a while and
> I finally spent a little time getting a start on it.  There
> is still a lot to do and not all of my descriptions are great,
> but I think we can document the rest in bits and pieces. I
> also added a note about what asics the function is applicable
> to. I tried to start with the more common and complex code.
> I was thinking it would make sense to have an informal
> documentation policy something like the following:
> 1. If you edit an undocumented function, add documentation
> 2. If you edit a documented function and change how it works,
>    update the documentation
> 3. All new functions added should be documented
> 
> Fulfulling all of these for stable fixes could pose problems
> so obviously there is some leeway.
> 
> Thoughts?
>
I think this is a good policy.  You might also want to specify the
documentation style to use.  It looks like you are using some form of
Doxygen comments.  I would also be in favor of a similar policy for
userspace code.

-Tom
 
> Alex Deucher (10):
>   drm/radeon: document radeon_device.c
>   drm/radeon: document radeon_kms.c
>   drm/radeon: document radeon_irq_kms.c
>   drm/radeon: document radeon_asic.c
>   drm/radeon: document radeon_fence.c
>   drm/radeon: document radeon_ring.c
>   drm/radeon: document non-VM functions in radeon_gart.c
>   drm/radeon: document VM functions in radeon_gart.c
>   drm/radeon: start to document the functions r100.c
>   drm/radeon: start to document evergreen.c
> 
>  drivers/gpu/drm/radeon/evergreen.c      |  120 ++++++++++
>  drivers/gpu/drm/radeon/r100.c           |  127 ++++++++++-
>  drivers/gpu/drm/radeon/radeon_asic.c    |   46 ++++
>  drivers/gpu/drm/radeon/radeon_device.c  |  344 +++++++++++++++++++++++++++-
>  drivers/gpu/drm/radeon/radeon_fence.c   |  373 +++++++++++++++++++++++++++++
>  drivers/gpu/drm/radeon/radeon_gart.c    |  391 ++++++++++++++++++++++++++++++-
>  drivers/gpu/drm/radeon/radeon_irq_kms.c |  150 ++++++++++++
>  drivers/gpu/drm/radeon/radeon_kms.c     |  126 ++++++++++
>  drivers/gpu/drm/radeon/radeon_ring.c    |  374 +++++++++++++++++++++++++++++-
>  9 files changed, 2041 insertions(+), 10 deletions(-)
> 
> -- 
> 1.7.7.5
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/dri-devel
> 

Re: [PATCH 00/10] Start documenting the radeon drm better

[Alex Deucher]

On Fri, Jun 29, 2012 at 10:42 AM, Tom Stellard <thomas.stellard@amd.com> wrote:
> On Fri, Jun 29, 2012 at 10:28:20AM -0400, alexdeucher@gmail.com wrote:
>> From: Alex Deucher <alexander.deucher@amd.com>
>>
>> This is something I've been wanting to do for a while and
>> I finally spent a little time getting a start on it.  There
>> is still a lot to do and not all of my descriptions are great,
>> but I think we can document the rest in bits and pieces. I
>> also added a note about what asics the function is applicable
>> to. I tried to start with the more common and complex code.
>> I was thinking it would make sense to have an informal
>> documentation policy something like the following:
>> 1. If you edit an undocumented function, add documentation
>> 2. If you edit a documented function and change how it works,
>>    update the documentation
>> 3. All new functions added should be documented
>>
>> Fulfulling all of these for stable fixes could pose problems
>> so obviously there is some leeway.
>>
>> Thoughts?
>>
> I think this is a good policy.  You might also want to specify the
> documentation style to use.  It looks like you are using some form of
> Doxygen comments.  I would also be in favor of a similar policy for
> userspace code.

I just copied the existing documentation bits in radeon and the drm in
general.  I'm open to other suggestions.

Alex

>
> -Tom
>
>> Alex Deucher (10):
>>   drm/radeon: document radeon_device.c
>>   drm/radeon: document radeon_kms.c
>>   drm/radeon: document radeon_irq_kms.c
>>   drm/radeon: document radeon_asic.c
>>   drm/radeon: document radeon_fence.c
>>   drm/radeon: document radeon_ring.c
>>   drm/radeon: document non-VM functions in radeon_gart.c
>>   drm/radeon: document VM functions in radeon_gart.c
>>   drm/radeon: start to document the functions r100.c
>>   drm/radeon: start to document evergreen.c
>>
>>  drivers/gpu/drm/radeon/evergreen.c      |  120 ++++++++++
>>  drivers/gpu/drm/radeon/r100.c           |  127 ++++++++++-
>>  drivers/gpu/drm/radeon/radeon_asic.c    |   46 ++++
>>  drivers/gpu/drm/radeon/radeon_device.c  |  344 +++++++++++++++++++++++++++-
>>  drivers/gpu/drm/radeon/radeon_fence.c   |  373 +++++++++++++++++++++++++++++
>>  drivers/gpu/drm/radeon/radeon_gart.c    |  391 ++++++++++++++++++++++++++++++-
>>  drivers/gpu/drm/radeon/radeon_irq_kms.c |  150 ++++++++++++
>>  drivers/gpu/drm/radeon/radeon_kms.c     |  126 ++++++++++
>>  drivers/gpu/drm/radeon/radeon_ring.c    |  374 +++++++++++++++++++++++++++++-
>>  9 files changed, 2041 insertions(+), 10 deletions(-)
>>
>> --
>> 1.7.7.5
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/dri-devel
>>
>

Re: [PATCH 00/10] Start documenting the radeon drm better

[Rafał Miłecki]

2012/6/29  <alexdeucher@gmail.com>:
> From: Alex Deucher <alexander.deucher@amd.com>
>
> This is something I've been wanting to do for a while and
> I finally spent a little time getting a start on it.  There
> is still a lot to do and not all of my descriptions are great,
> but I think we can document the rest in bits and pieces. I
> also added a note about what asics the function is applicable
> to. I tried to start with the more common and complex code.
> I was thinking it would make sense to have an informal
> documentation policy something like the following:
> 1. If you edit an undocumented function, add documentation
> 2. If you edit a documented function and change how it works,
>   update the documentation
> 3. All new functions added should be documented
>
> Fulfulling all of these for stable fixes could pose problems
> so obviously there is some leeway.
>
> Thoughts?

I'd try to avoid repeating definitions over and over, but generally
THIS IS GREAT. Thanks a lot for doing that!

-- 
Rafał
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel

[PATCH 01/10] drm/radeon: document radeon_device.c (v2)

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

Adds documentation to most of the functions in
radeon_device.c

v2: split out general descriptions as per Christian's
comments.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/radeon_device.c |  313 +++++++++++++++++++++++++++++++-
 1 files changed, 310 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
index f654ba8..926d7e8 100644
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -96,8 +96,12 @@ static const char radeon_family_name[][16] = {
 	"LAST",
 };
 
-/*
- * Clear GPU surface registers.
+/**
+ * radeon_surface_init - Clear GPU surface registers.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Clear GPU surface registers (r1xx-r5xx).
  */
 void radeon_surface_init(struct radeon_device *rdev)
 {
@@ -119,6 +123,13 @@ void radeon_surface_init(struct radeon_device *rdev)
 /*
  * GPU scratch registers helpers function.
  */
+/**
+ * radeon_scratch_init - Init scratch register driver information.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Init CP scratch register driver information (r1xx-r5xx)
+ */
 void radeon_scratch_init(struct radeon_device *rdev)
 {
 	int i;
@@ -136,6 +147,15 @@ void radeon_scratch_init(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * radeon_scratch_get - Allocate a scratch register
+ *
+ * @rdev: radeon_device pointer
+ * @reg: scratch register mmio offset
+ *
+ * Allocate a CP scratch register for use by the driver (all asics).
+ * Returns 0 on success or -EINVAL on failure.
+ */
 int radeon_scratch_get(struct radeon_device *rdev, uint32_t *reg)
 {
 	int i;
@@ -150,6 +170,14 @@ int radeon_scratch_get(struct radeon_device *rdev, uint32_t *reg)
 	return -EINVAL;
 }
 
+/**
+ * radeon_scratch_free - Free a scratch register
+ *
+ * @rdev: radeon_device pointer
+ * @reg: scratch register mmio offset
+ *
+ * Free a CP scratch register allocated for use by the driver (all asics)
+ */
 void radeon_scratch_free(struct radeon_device *rdev, uint32_t reg)
 {
 	int i;
@@ -162,6 +190,20 @@ void radeon_scratch_free(struct radeon_device *rdev, uint32_t reg)
 	}
 }
 
+/*
+ * radeon_wb_*()
+ * Writeback is the the method by which the the GPU updates special pages
+ * in memory with the status of certain GPU events (fences, ring pointers,
+ * etc.).
+ */
+
+/**
+ * radeon_wb_disable - Disable Writeback
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Disables Writeback (all asics).  Used for suspend.
+ */
 void radeon_wb_disable(struct radeon_device *rdev)
 {
 	int r;
@@ -177,6 +219,14 @@ void radeon_wb_disable(struct radeon_device *rdev)
 	rdev->wb.enabled = false;
 }
 
+/**
+ * radeon_wb_fini - Disable Writeback and free memory
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Disables Writeback and frees the Writeback memory (all asics).
+ * Used at driver shutdown.
+ */
 void radeon_wb_fini(struct radeon_device *rdev)
 {
 	radeon_wb_disable(rdev);
@@ -187,6 +237,15 @@ void radeon_wb_fini(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * radeon_wb_init- Init Writeback driver info and allocate memory
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Disables Writeback and frees the Writeback memory (all asics).
+ * Used at driver startup.
+ * Returns 0 on success or an -error on failure.
+ */
 int radeon_wb_init(struct radeon_device *rdev)
 {
 	int r;
@@ -355,6 +414,15 @@ void radeon_gtt_location(struct radeon_device *rdev, struct radeon_mc *mc)
 /*
  * GPU helpers function.
  */
+/**
+ * radeon_card_posted - check if the hw has already been initialized
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Check if the asic has been initialized (all asics).
+ * Used at driver startup.
+ * Returns true if initialized or false if not.
+ */
 bool radeon_card_posted(struct radeon_device *rdev)
 {
 	uint32_t reg;
@@ -404,6 +472,14 @@ bool radeon_card_posted(struct radeon_device *rdev)
 
 }
 
+/**
+ * radeon_update_bandwidth_info - update display bandwidth params
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Used when sclk/mclk are switched or display modes are set.
+ * params are used to calculate display watermarks (all asics)
+ */
 void radeon_update_bandwidth_info(struct radeon_device *rdev)
 {
 	fixed20_12 a;
@@ -424,6 +500,15 @@ void radeon_update_bandwidth_info(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * radeon_boot_test_post_card - check and possibly initialize the hw
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Check if the asic is initialized and if not, attempt to initialize
+ * it (all asics).
+ * Returns true if initialized or false if not.
+ */
 bool radeon_boot_test_post_card(struct radeon_device *rdev)
 {
 	if (radeon_card_posted(rdev))
@@ -442,6 +527,16 @@ bool radeon_boot_test_post_card(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * radeon_dummy_page_init - init dummy page used by the driver
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Allocate the dummy page used by the driver (all asics).
+ * This dummy page is used by the driver as a filler for gart entries
+ * when pages are taken out of the GART
+ * Returns 0 on sucess, -ENOMEM on failure.
+ */
 int radeon_dummy_page_init(struct radeon_device *rdev)
 {
 	if (rdev->dummy_page.page)
@@ -460,6 +555,13 @@ int radeon_dummy_page_init(struct radeon_device *rdev)
 	return 0;
 }
 
+/**
+ * radeon_dummy_page_fini - free dummy page used by the driver
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Frees the dummy page used by the driver (all asics).
+ */
 void radeon_dummy_page_fini(struct radeon_device *rdev)
 {
 	if (rdev->dummy_page.page == NULL)
@@ -472,6 +574,23 @@ void radeon_dummy_page_fini(struct radeon_device *rdev)
 
 
 /* ATOM accessor methods */
+/*
+ * ATOM is an interpreted byte code stored in tables in the vbios.  The
+ * driver registers callbacks to access registers and the interpreter
+ * in the driver parses the tables and executes then to program specific
+ * actions (set display modes, asic init, etc.).  See radeon_atombios.c,
+ * atombios.h, and atom.c
+ */
+
+/**
+ * cail_pll_read - read PLL register
+ *
+ * @info: atom card_info pointer
+ * @reg: PLL register offset
+ *
+ * Provides a PLL register accessor for the atom interpreter (r4xx+).
+ * Returns the value of the PLL register.
+ */
 static uint32_t cail_pll_read(struct card_info *info, uint32_t reg)
 {
 	struct radeon_device *rdev = info->dev->dev_private;
@@ -481,6 +600,15 @@ static uint32_t cail_pll_read(struct card_info *info, uint32_t reg)
 	return r;
 }
 
+/**
+ * cail_pll_write - write PLL register
+ *
+ * @info: atom card_info pointer
+ * @reg: PLL register offset
+ * @val: value to write to the pll register
+ *
+ * Provides a PLL register accessor for the atom interpreter (r4xx+).
+ */
 static void cail_pll_write(struct card_info *info, uint32_t reg, uint32_t val)
 {
 	struct radeon_device *rdev = info->dev->dev_private;
@@ -488,6 +616,15 @@ static void cail_pll_write(struct card_info *info, uint32_t reg, uint32_t val)
 	rdev->pll_wreg(rdev, reg, val);
 }
 
+/**
+ * cail_mc_read - read MC (Memory Controller) register
+ *
+ * @info: atom card_info pointer
+ * @reg: MC register offset
+ *
+ * Provides an MC register accessor for the atom interpreter (r4xx+).
+ * Returns the value of the MC register.
+ */
 static uint32_t cail_mc_read(struct card_info *info, uint32_t reg)
 {
 	struct radeon_device *rdev = info->dev->dev_private;
@@ -497,6 +634,15 @@ static uint32_t cail_mc_read(struct card_info *info, uint32_t reg)
 	return r;
 }
 
+/**
+ * cail_mc_write - write MC (Memory Controller) register
+ *
+ * @info: atom card_info pointer
+ * @reg: MC register offset
+ * @val: value to write to the pll register
+ *
+ * Provides a MC register accessor for the atom interpreter (r4xx+).
+ */
 static void cail_mc_write(struct card_info *info, uint32_t reg, uint32_t val)
 {
 	struct radeon_device *rdev = info->dev->dev_private;
@@ -504,6 +650,15 @@ static void cail_mc_write(struct card_info *info, uint32_t reg, uint32_t val)
 	rdev->mc_wreg(rdev, reg, val);
 }
 
+/**
+ * cail_reg_write - write MMIO register
+ *
+ * @info: atom card_info pointer
+ * @reg: MMIO register offset
+ * @val: value to write to the pll register
+ *
+ * Provides a MMIO register accessor for the atom interpreter (r4xx+).
+ */
 static void cail_reg_write(struct card_info *info, uint32_t reg, uint32_t val)
 {
 	struct radeon_device *rdev = info->dev->dev_private;
@@ -511,6 +666,15 @@ static void cail_reg_write(struct card_info *info, uint32_t reg, uint32_t val)
 	WREG32(reg*4, val);
 }
 
+/**
+ * cail_reg_read - read MMIO register
+ *
+ * @info: atom card_info pointer
+ * @reg: MMIO register offset
+ *
+ * Provides an MMIO register accessor for the atom interpreter (r4xx+).
+ * Returns the value of the MMIO register.
+ */
 static uint32_t cail_reg_read(struct card_info *info, uint32_t reg)
 {
 	struct radeon_device *rdev = info->dev->dev_private;
@@ -520,6 +684,15 @@ static uint32_t cail_reg_read(struct card_info *info, uint32_t reg)
 	return r;
 }
 
+/**
+ * cail_ioreg_write - write IO register
+ *
+ * @info: atom card_info pointer
+ * @reg: IO register offset
+ * @val: value to write to the pll register
+ *
+ * Provides a IO register accessor for the atom interpreter (r4xx+).
+ */
 static void cail_ioreg_write(struct card_info *info, uint32_t reg, uint32_t val)
 {
 	struct radeon_device *rdev = info->dev->dev_private;
@@ -527,6 +700,15 @@ static void cail_ioreg_write(struct card_info *info, uint32_t reg, uint32_t val)
 	WREG32_IO(reg*4, val);
 }
 
+/**
+ * cail_ioreg_read - read IO register
+ *
+ * @info: atom card_info pointer
+ * @reg: IO register offset
+ *
+ * Provides an IO register accessor for the atom interpreter (r4xx+).
+ * Returns the value of the IO register.
+ */
 static uint32_t cail_ioreg_read(struct card_info *info, uint32_t reg)
 {
 	struct radeon_device *rdev = info->dev->dev_private;
@@ -536,6 +718,16 @@ static uint32_t cail_ioreg_read(struct card_info *info, uint32_t reg)
 	return r;
 }
 
+/**
+ * radeon_atombios_init - init the driver info and callbacks for atombios
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Initializes the driver info and register access callbacks for the
+ * ATOM interpreter (r4xx+).
+ * Returns 0 on sucess, -ENOMEM on failure.
+ * Called at driver startup.
+ */
 int radeon_atombios_init(struct radeon_device *rdev)
 {
 	struct card_info *atom_card_info =
@@ -569,6 +761,15 @@ int radeon_atombios_init(struct radeon_device *rdev)
 	return 0;
 }
 
+/**
+ * radeon_atombios_fini - free the driver info and callbacks for atombios
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Frees the driver info and register access callbacks for the ATOM
+ * interpreter (r4xx+).
+ * Called at driver shutdown.
+ */
 void radeon_atombios_fini(struct radeon_device *rdev)
 {
 	if (rdev->mode_info.atom_context) {
@@ -578,17 +779,50 @@ void radeon_atombios_fini(struct radeon_device *rdev)
 	kfree(rdev->mode_info.atom_card_info);
 }
 
+/* COMBIOS */
+/*
+ * COMBIOS is the bios format prior to ATOM. It provides
+ * command tables similar to ATOM, but doesn't have a unified
+ * parser.  See radeon_combios.c
+ */
+
+/**
+ * radeon_combios_init - init the driver info for combios
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Initializes the driver info for combios (r1xx-r3xx).
+ * Returns 0 on sucess.
+ * Called at driver startup.
+ */
 int radeon_combios_init(struct radeon_device *rdev)
 {
 	radeon_combios_initialize_bios_scratch_regs(rdev->ddev);
 	return 0;
 }
 
+/**
+ * radeon_combios_fini - free the driver info for combios
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Frees the driver info for combios (r1xx-r3xx).
+ * Called at driver shutdown.
+ */
 void radeon_combios_fini(struct radeon_device *rdev)
 {
 }
 
-/* if we get transitioned to only one device, tak VGA back */
+/* if we get transitioned to only one device, take VGA back */
+/**
+ * radeon_vga_set_decode - enable/disable vga decode
+ *
+ * @cookie: radeon_device pointer
+ * @state: enable/disable vga decode
+ *
+ * Enable/disable vga decode (all asics).
+ * Returns VGA resource flags.
+ */
 static unsigned int radeon_vga_set_decode(void *cookie, bool state)
 {
 	struct radeon_device *rdev = cookie;
@@ -600,6 +834,14 @@ static unsigned int radeon_vga_set_decode(void *cookie, bool state)
 		return VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM;
 }
 
+/**
+ * radeon_check_arguments - validate module params
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Validates certain module parameters and updates
+ * the associated values used by the driver (all asics).
+ */
 void radeon_check_arguments(struct radeon_device *rdev)
 {
 	/* vramlimit must be a power of two */
@@ -666,6 +908,15 @@ void radeon_check_arguments(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * radeon_switcheroo_set_state - set switcheroo state
+ *
+ * @pdev: pci dev pointer
+ * @state: vga switcheroo state
+ *
+ * Callback for the switcheroo driver.  Suspends or resumes the
+ * the asics before or after it is powered up using ACPI methods.
+ */
 static void radeon_switcheroo_set_state(struct pci_dev *pdev, enum vga_switcheroo_state state)
 {
 	struct drm_device *dev = pci_get_drvdata(pdev);
@@ -686,6 +937,15 @@ static void radeon_switcheroo_set_state(struct pci_dev *pdev, enum vga_switchero
 	}
 }
 
+/**
+ * radeon_switcheroo_can_switch - see if switcheroo state can change
+ *
+ * @pdev: pci dev pointer
+ *
+ * Callback for the switcheroo driver.  Check of the switcheroo
+ * state can be changed.
+ * Returns true if the state can be changed, false if not.
+ */
 static bool radeon_switcheroo_can_switch(struct pci_dev *pdev)
 {
 	struct drm_device *dev = pci_get_drvdata(pdev);
@@ -703,6 +963,18 @@ static const struct vga_switcheroo_client_ops radeon_switcheroo_ops = {
 	.can_switch = radeon_switcheroo_can_switch,
 };
 
+/**
+ * radeon_device_init - initialize the driver
+ *
+ * @rdev: radeon_device pointer
+ * @pdev: drm dev pointer
+ * @pdev: pci dev pointer
+ * @flags: driver flags
+ *
+ * Initializes the driver info and hw (all asics).
+ * Returns 0 for success or an error on failure.
+ * Called at driver startup.
+ */
 int radeon_device_init(struct radeon_device *rdev,
 		       struct drm_device *ddev,
 		       struct pci_dev *pdev,
@@ -846,6 +1118,14 @@ int radeon_device_init(struct radeon_device *rdev,
 
 static void radeon_debugfs_remove_files(struct radeon_device *rdev);
 
+/**
+ * radeon_device_fini - tear down the driver
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Tear down the driver info (all asics).
+ * Called at driver shutdown.
+ */
 void radeon_device_fini(struct radeon_device *rdev)
 {
 	DRM_INFO("radeon: finishing device.\n");
@@ -867,6 +1147,16 @@ void radeon_device_fini(struct radeon_device *rdev)
 /*
  * Suspend & resume.
  */
+/**
+ * radeon_suspend_kms - initiate device suspend
+ *
+ * @pdev: drm dev pointer
+ * @state: suspend state
+ *
+ * Puts the hw in the suspend state (all asics).
+ * Returns 0 for success or an error on failure.
+ * Called at driver suspend.
+ */
 int radeon_suspend_kms(struct drm_device *dev, pm_message_t state)
 {
 	struct radeon_device *rdev;
@@ -941,6 +1231,15 @@ int radeon_suspend_kms(struct drm_device *dev, pm_message_t state)
 	return 0;
 }
 
+/**
+ * radeon_resume_kms - initiate device resume
+ *
+ * @pdev: drm dev pointer
+ *
+ * Bring the hw back to operating state (all asics).
+ * Returns 0 for success or an error on failure.
+ * Called at driver resume.
+ */
 int radeon_resume_kms(struct drm_device *dev)
 {
 	struct drm_connector *connector;
@@ -983,6 +1282,14 @@ int radeon_resume_kms(struct drm_device *dev)
 	return 0;
 }
 
+/**
+ * radeon_gpu_reset - reset the asic
+ *
+ * @rdev: radeon device pointer
+ *
+ * Attempt the reset the GPU if it has hung (all asics).
+ * Returns 0 for success or an error on failure.
+ */
 int radeon_gpu_reset(struct radeon_device *rdev)
 {
 	int r;
-- 
1.7.7.5

[PATCH 02/10] drm/radeon: document radeon_kms.c

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

Adds documentation to most of the functions in
radeon_kms.c

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/radeon_kms.c |  126 +++++++++++++++++++++++++++++++++++
 1 files changed, 126 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_kms.c b/drivers/gpu/drm/radeon/radeon_kms.c
index 18b81d6..1d73f16 100644
--- a/drivers/gpu/drm/radeon/radeon_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_kms.c
@@ -33,6 +33,17 @@
 #include <linux/vga_switcheroo.h>
 #include <linux/slab.h>
 
+/**
+ * radeon_driver_unload_kms - Main unload function for KMS.
+ *
+ * @dev: drm dev pointer
+ *
+ * This is the main unload function for KMS (all asics).
+ * It calls radeon_modeset_fini() to tear down the
+ * displays, and radeon_device_fini() to tear down
+ * the rest of the device (CP, writeback, etc.).
+ * Returns 0 on success.
+ */
 int radeon_driver_unload_kms(struct drm_device *dev)
 {
 	struct radeon_device *rdev = dev->dev_private;
@@ -46,6 +57,19 @@ int radeon_driver_unload_kms(struct drm_device *dev)
 	return 0;
 }
 
+/**
+ * radeon_driver_load_kms - Main load function for KMS.
+ *
+ * @dev: drm dev pointer
+ * @flags: device flags
+ *
+ * This is the main load function for KMS (all asics).
+ * It calls radeon_device_init() to set up the non-display
+ * parts of the chip (asic init, CP, writeback, etc.), and
+ * radeon_modeset_init() to set up the display parts
+ * (crtcs, encoders, hotplug detect, etc.).
+ * Returns 0 on success, error on failure.
+ */
 int radeon_driver_load_kms(struct drm_device *dev, unsigned long flags)
 {
 	struct radeon_device *rdev;
@@ -96,6 +120,16 @@ out:
 	return r;
 }
 
+/**
+ * radeon_set_filp_rights - Set filp right.
+ *
+ * @dev: drm dev pointer
+ * @owner: drm file
+ * @applier: drm file
+ * @value: value
+ *
+ * Sets the filp rights for the device (all asics).
+ */
 static void radeon_set_filp_rights(struct drm_device *dev,
 				   struct drm_file **owner,
 				   struct drm_file *applier,
@@ -118,6 +152,18 @@ static void radeon_set_filp_rights(struct drm_device *dev,
 /*
  * Userspace get information ioctl
  */
+/**
+ * radeon_info_ioctl - answer a device specific request.
+ *
+ * @rdev: radeon device pointer
+ * @data: request object
+ * @filp: drm filp
+ *
+ * This function is used to pass device specific parameters to the userspace
+ * drivers.  Examples include: pci device id, pipeline parms, tiling params,
+ * etc. (all asics).
+ * Returns 0 on success, -EINVAL on failure.
+ */
 int radeon_info_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 {
 	struct radeon_device *rdev = dev->dev_private;
@@ -301,16 +347,40 @@ int radeon_info_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 /*
  * Outdated mess for old drm with Xorg being in charge (void function now).
  */
+/**
+ * radeon_driver_firstopen_kms - drm callback for first open
+ *
+ * @dev: drm dev pointer
+ *
+ * Nothing to be done for KMS (all asics).
+ * Returns 0 on success.
+ */
 int radeon_driver_firstopen_kms(struct drm_device *dev)
 {
 	return 0;
 }
 
+/**
+ * radeon_driver_firstopen_kms - drm callback for last close
+ *
+ * @dev: drm dev pointer
+ *
+ * Switch vga switcheroo state after last close (all asics).
+ */
 void radeon_driver_lastclose_kms(struct drm_device *dev)
 {
 	vga_switcheroo_process_delayed_switch();
 }
 
+/**
+ * radeon_driver_open_kms - drm callback for open
+ *
+ * @dev: drm dev pointer
+ * @file_priv: drm file
+ *
+ * On device open, init vm on cayman+ (all asics).
+ * Returns 0 on success, error on failure.
+ */
 int radeon_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv)
 {
 	struct radeon_device *rdev = dev->dev_private;
@@ -339,6 +409,14 @@ int radeon_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv)
 	return 0;
 }
 
+/**
+ * radeon_driver_postclose_kms - drm callback for post close
+ *
+ * @dev: drm dev pointer
+ * @file_priv: drm file
+ *
+ * On device post close, tear down vm on cayman+ (all asics).
+ */
 void radeon_driver_postclose_kms(struct drm_device *dev,
 				 struct drm_file *file_priv)
 {
@@ -354,6 +432,15 @@ void radeon_driver_postclose_kms(struct drm_device *dev,
 	}
 }
 
+/**
+ * radeon_driver_preclose_kms - drm callback for pre close
+ *
+ * @dev: drm dev pointer
+ * @file_priv: drm file
+ *
+ * On device pre close, tear down hyperz and cmask filps on r1xx-r5xx
+ * (all asics).
+ */
 void radeon_driver_preclose_kms(struct drm_device *dev,
 				struct drm_file *file_priv)
 {
@@ -367,6 +454,15 @@ void radeon_driver_preclose_kms(struct drm_device *dev,
 /*
  * VBlank related functions.
  */
+/**
+ * radeon_get_vblank_counter_kms - get frame count
+ *
+ * @dev: drm dev pointer
+ * @crtc: crtc to get the frame count from
+ *
+ * Gets the frame count on the requested crtc (all asics).
+ * Returns frame count on success, -EINVAL on failure.
+ */
 u32 radeon_get_vblank_counter_kms(struct drm_device *dev, int crtc)
 {
 	struct radeon_device *rdev = dev->dev_private;
@@ -379,6 +475,15 @@ u32 radeon_get_vblank_counter_kms(struct drm_device *dev, int crtc)
 	return radeon_get_vblank_counter(rdev, crtc);
 }
 
+/**
+ * radeon_enable_vblank_kms - enable vblank interrupt
+ *
+ * @dev: drm dev pointer
+ * @crtc: crtc to enable vblank interrupt for
+ *
+ * Enable the interrupt on the requested crtc (all asics).
+ * Returns 0 on success, -EINVAL on failure.
+ */
 int radeon_enable_vblank_kms(struct drm_device *dev, int crtc)
 {
 	struct radeon_device *rdev = dev->dev_private;
@@ -397,6 +502,14 @@ int radeon_enable_vblank_kms(struct drm_device *dev, int crtc)
 	return r;
 }
 
+/**
+ * radeon_disable_vblank_kms - disable vblank interrupt
+ *
+ * @dev: drm dev pointer
+ * @crtc: crtc to disable vblank interrupt for
+ *
+ * Disable the interrupt on the requested crtc (all asics).
+ */
 void radeon_disable_vblank_kms(struct drm_device *dev, int crtc)
 {
 	struct radeon_device *rdev = dev->dev_private;
@@ -413,6 +526,19 @@ void radeon_disable_vblank_kms(struct drm_device *dev, int crtc)
 	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
 }
 
+/**
+ * radeon_get_vblank_timestamp_kms - get vblank timestamp
+ *
+ * @dev: drm dev pointer
+ * @crtc: crtc to get the timestamp for
+ * @max_error: max error
+ * @vblank_time: time value
+ * @flags: flags passed to the driver
+ *
+ * Gets the timestamp on the requested crtc based on the
+ * scanout position.  (all asics).
+ * Returns postive status flags on success, negative error on failure.
+ */
 int radeon_get_vblank_timestamp_kms(struct drm_device *dev, int crtc,
 				    int *max_error,
 				    struct timeval *vblank_time,
-- 
1.7.7.5

[PATCH 03/10] drm/radeon: document radeon_irq_kms.c

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

Adds documentation to most of the functions in
radeon_irq_kms.c

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/radeon_irq_kms.c |  150 +++++++++++++++++++++++++++++++
 1 files changed, 150 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_irq_kms.c b/drivers/gpu/drm/radeon/radeon_irq_kms.c
index 6664514..afaa172 100644
--- a/drivers/gpu/drm/radeon/radeon_irq_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_irq_kms.c
@@ -34,6 +34,15 @@
 
 #define RADEON_WAIT_IDLE_TIMEOUT 200
 
+/**
+ * radeon_driver_irq_handler_kms - irq handler for KMS
+ *
+ * @DRM_IRQ_ARGS: args
+ *
+ * This is the irq handler for the radeon KMS driver (all asics).
+ * radeon_irq_process is a macro that points to the per-asic
+ * irq handler callback.
+ */
 irqreturn_t radeon_driver_irq_handler_kms(DRM_IRQ_ARGS)
 {
 	struct drm_device *dev = (struct drm_device *) arg;
@@ -45,6 +54,17 @@ irqreturn_t radeon_driver_irq_handler_kms(DRM_IRQ_ARGS)
 /*
  * Handle hotplug events outside the interrupt handler proper.
  */
+/**
+ * radeon_hotplug_work_func - display hotplug work handler
+ *
+ * @work: work struct
+ *
+ * This is the hot plug event work handler (all asics).
+ * The work gets scheduled from the irq handler if there
+ * was a hot plug interrupt.  It walks the connector table
+ * and calls the hotplug handler for each one, then sends
+ * a drm hotplug event to alert userspace.
+ */
 static void radeon_hotplug_work_func(struct work_struct *work)
 {
 	struct radeon_device *rdev = container_of(work, struct radeon_device,
@@ -61,6 +81,14 @@ static void radeon_hotplug_work_func(struct work_struct *work)
 	drm_helper_hpd_irq_event(dev);
 }
 
+/**
+ * radeon_driver_irq_preinstall_kms - drm irq preinstall callback
+ *
+ * @dev: drm dev pointer
+ *
+ * Gets the hw ready to enable irqs (all asics).
+ * This function disables all interrupt sources on the GPU.
+ */
 void radeon_driver_irq_preinstall_kms(struct drm_device *dev)
 {
 	struct radeon_device *rdev = dev->dev_private;
@@ -85,12 +113,27 @@ void radeon_driver_irq_preinstall_kms(struct drm_device *dev)
 	radeon_irq_process(rdev);
 }
 
+/**
+ * radeon_driver_irq_postinstall_kms - drm irq preinstall callback
+ *
+ * @dev: drm dev pointer
+ *
+ * Handles stuff to be done after enabling irqs (all asics).
+ * Returns 0 on success.
+ */
 int radeon_driver_irq_postinstall_kms(struct drm_device *dev)
 {
 	dev->max_vblank_count = 0x001fffff;
 	return 0;
 }
 
+/**
+ * radeon_driver_irq_uninstall_kms - drm irq uninstall callback
+ *
+ * @dev: drm dev pointer
+ *
+ * This function disables all interrupt sources on the GPU (all asics).
+ */
 void radeon_driver_irq_uninstall_kms(struct drm_device *dev)
 {
 	struct radeon_device *rdev = dev->dev_private;
@@ -116,6 +159,16 @@ void radeon_driver_irq_uninstall_kms(struct drm_device *dev)
 	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
 }
 
+/**
+ * radeon_msi_ok - asic specific msi checks
+ *
+ * @rdev: radeon device pointer
+ *
+ * Handles asic specific MSI checks to determine if
+ * MSIs should be enabled on a particular chip (all asics).
+ * Returns true if MSIs should be enabled, false if MSIs
+ * should not be enabled.
+ */
 static bool radeon_msi_ok(struct radeon_device *rdev)
 {
 	/* RV370/RV380 was first asic with MSI support */
@@ -168,6 +221,14 @@ static bool radeon_msi_ok(struct radeon_device *rdev)
 	return true;
 }
 
+/**
+ * radeon_irq_kms_init - init driver interrupt info
+ *
+ * @rdev: radeon device pointer
+ *
+ * Sets up the work irq handlers, vblank init, MSIs, etc. (all asics).
+ * Returns 0 for success, error for failure.
+ */
 int radeon_irq_kms_init(struct radeon_device *rdev)
 {
 	int r = 0;
@@ -200,6 +261,13 @@ int radeon_irq_kms_init(struct radeon_device *rdev)
 	return 0;
 }
 
+/**
+ * radeon_irq_kms_fini - tear down driver interrrupt info
+ *
+ * @rdev: radeon device pointer
+ *
+ * Tears down the work irq handlers, vblank handlers, MSIs, etc. (all asics).
+ */
 void radeon_irq_kms_fini(struct radeon_device *rdev)
 {
 	drm_vblank_cleanup(rdev->ddev);
@@ -212,6 +280,16 @@ void radeon_irq_kms_fini(struct radeon_device *rdev)
 	flush_work_sync(&rdev->hotplug_work);
 }
 
+/**
+ * radeon_irq_kms_sw_irq_get - enable software interrupt
+ *
+ * @rdev: radeon device pointer
+ * @ring: ring whose interrupt you want to enable
+ *
+ * Enables the software interrupt for a specific ring (all asics).
+ * The software interrupt is generally used to signal a fence on
+ * a particular ring.
+ */
 void radeon_irq_kms_sw_irq_get(struct radeon_device *rdev, int ring)
 {
 	unsigned long irqflags;
@@ -226,6 +304,16 @@ void radeon_irq_kms_sw_irq_get(struct radeon_device *rdev, int ring)
 	}
 }
 
+/**
+ * radeon_irq_kms_sw_irq_put - disable software interrupt
+ *
+ * @rdev: radeon device pointer
+ * @ring: ring whose interrupt you want to disable
+ *
+ * Disables the software interrupt for a specific ring (all asics).
+ * The software interrupt is generally used to signal a fence on
+ * a particular ring.
+ */
 void radeon_irq_kms_sw_irq_put(struct radeon_device *rdev, int ring)
 {
 	unsigned long irqflags;
@@ -240,6 +328,15 @@ void radeon_irq_kms_sw_irq_put(struct radeon_device *rdev, int ring)
 	}
 }
 
+/**
+ * radeon_irq_kms_pflip_irq_get - enable pageflip interrupt
+ *
+ * @rdev: radeon device pointer
+ * @crtc: crtc whose interrupt you want to enable
+ *
+ * Enables the pageflip interrupt for a specific crtc (all asics).
+ * For pageflips we use the vblank interrupt source.
+ */
 void radeon_irq_kms_pflip_irq_get(struct radeon_device *rdev, int crtc)
 {
 	unsigned long irqflags;
@@ -257,6 +354,15 @@ void radeon_irq_kms_pflip_irq_get(struct radeon_device *rdev, int crtc)
 	}
 }
 
+/**
+ * radeon_irq_kms_pflip_irq_put - disable pageflip interrupt
+ *
+ * @rdev: radeon device pointer
+ * @crtc: crtc whose interrupt you want to disable
+ *
+ * Disables the pageflip interrupt for a specific crtc (all asics).
+ * For pageflips we use the vblank interrupt source.
+ */
 void radeon_irq_kms_pflip_irq_put(struct radeon_device *rdev, int crtc)
 {
 	unsigned long irqflags;
@@ -274,6 +380,14 @@ void radeon_irq_kms_pflip_irq_put(struct radeon_device *rdev, int crtc)
 	}
 }
 
+/**
+ * radeon_irq_kms_enable_afmt - enable audio format change interrupt
+ *
+ * @rdev: radeon device pointer
+ * @block: afmt block whose interrupt you want to enable
+ *
+ * Enables the afmt change interrupt for a specific afmt block (all asics).
+ */
 void radeon_irq_kms_enable_afmt(struct radeon_device *rdev, int block)
 {
 	unsigned long irqflags;
@@ -285,6 +399,14 @@ void radeon_irq_kms_enable_afmt(struct radeon_device *rdev, int block)
 
 }
 
+/**
+ * radeon_irq_kms_disable_afmt - disable audio format change interrupt
+ *
+ * @rdev: radeon device pointer
+ * @block: afmt block whose interrupt you want to disable
+ *
+ * Disables the afmt change interrupt for a specific afmt block (all asics).
+ */
 void radeon_irq_kms_disable_afmt(struct radeon_device *rdev, int block)
 {
 	unsigned long irqflags;
@@ -295,6 +417,14 @@ void radeon_irq_kms_disable_afmt(struct radeon_device *rdev, int block)
 	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
 }
 
+/**
+ * radeon_irq_kms_enable_hpd - enable hotplug detect interrupt
+ *
+ * @rdev: radeon device pointer
+ * @hpd_mask: mask of hpd pins you want to enable.
+ *
+ * Enables the hotplug detect interrupt for a specific hpd pin (all asics).
+ */
 void radeon_irq_kms_enable_hpd(struct radeon_device *rdev, unsigned hpd_mask)
 {
 	unsigned long irqflags;
@@ -307,6 +437,14 @@ void radeon_irq_kms_enable_hpd(struct radeon_device *rdev, unsigned hpd_mask)
 	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
 }
 
+/**
+ * radeon_irq_kms_disable_hpd - disable hotplug detect interrupt
+ *
+ * @rdev: radeon device pointer
+ * @hpd_mask: mask of hpd pins you want to disable.
+ *
+ * Disables the hotplug detect interrupt for a specific hpd pin (all asics).
+ */
 void radeon_irq_kms_disable_hpd(struct radeon_device *rdev, unsigned hpd_mask)
 {
 	unsigned long irqflags;
@@ -319,6 +457,18 @@ void radeon_irq_kms_disable_hpd(struct radeon_device *rdev, unsigned hpd_mask)
 	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
 }
 
+/**
+ * radeon_irq_kms_wait_gui_idle - waits for drawing engine to be idle
+ *
+ * @rdev: radeon device pointer
+ *
+ * Enabled the GUI idle interrupt and waits for it to fire (r6xx+).
+ * This is currently used to make sure the 3D engine is idle for power
+ * management, but should be replaces with proper fence waits.
+ * GUI idle interrupts don't work very well on pre-r6xx hw and it also
+ * does not take into account other aspects of the chip that may be busy.
+ * DO NOT USE GOING FORWARD.
+ */
 int radeon_irq_kms_wait_gui_idle(struct radeon_device *rdev)
 {
 	unsigned long irqflags;
-- 
1.7.7.5

[PATCH 04/10] drm/radeon: document radeon_asic.c

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

Adds documentation to most of the functions in
radeon_asic.c

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/radeon_asic.c |   46 ++++++++++++++++++++++++++++++++++
 1 files changed, 46 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_asic.c b/drivers/gpu/drm/radeon/radeon_asic.c
index f533df5..973417c 100644
--- a/drivers/gpu/drm/radeon/radeon_asic.c
+++ b/drivers/gpu/drm/radeon/radeon_asic.c
@@ -40,6 +40,16 @@
 /*
  * Registers accessors functions.
  */
+/**
+ * radeon_invalid_rreg - dummy reg read function
+ *
+ * @rdev: radeon device pointer
+ * @reg: offset of register
+ *
+ * Dummy register read function.  Used for register blocks
+ * that certain asics don't have (all asics).
+ * Returns the value in the register.
+ */
 static uint32_t radeon_invalid_rreg(struct radeon_device *rdev, uint32_t reg)
 {
 	DRM_ERROR("Invalid callback to read register 0x%04X\n", reg);
@@ -47,6 +57,16 @@ static uint32_t radeon_invalid_rreg(struct radeon_device *rdev, uint32_t reg)
 	return 0;
 }
 
+/**
+ * radeon_invalid_wreg - dummy reg write function
+ *
+ * @rdev: radeon device pointer
+ * @reg: offset of register
+ * @v: value to write to the register
+ *
+ * Dummy register read function.  Used for register blocks
+ * that certain asics don't have (all asics).
+ */
 static void radeon_invalid_wreg(struct radeon_device *rdev, uint32_t reg, uint32_t v)
 {
 	DRM_ERROR("Invalid callback to write register 0x%04X with 0x%08X\n",
@@ -54,6 +74,14 @@ static void radeon_invalid_wreg(struct radeon_device *rdev, uint32_t reg, uint32
 	BUG_ON(1);
 }
 
+/**
+ * radeon_register_accessor_init - sets up the register accessor callbacks
+ *
+ * @rdev: radeon device pointer
+ *
+ * Sets up the register accessor callbacks for various register
+ * apertures.  Not all asics have all apertures (all asics).
+ */
 static void radeon_register_accessor_init(struct radeon_device *rdev)
 {
 	rdev->mc_rreg = &radeon_invalid_rreg;
@@ -102,6 +130,14 @@ static void radeon_register_accessor_init(struct radeon_device *rdev)
 
 
 /* helper to disable agp */
+/**
+ * radeon_agp_disable - AGP disable helper function
+ *
+ * @rdev: radeon device pointer
+ *
+ * Removes AGP flags and changes the gart callbacks on AGP
+ * cards when using the internal gart rather than AGP (all asics).
+ */
 void radeon_agp_disable(struct radeon_device *rdev)
 {
 	rdev->flags &= ~RADEON_IS_AGP;
@@ -1608,6 +1644,16 @@ static struct radeon_asic si_asic = {
 	},
 };
 
+/**
+ * radeon_asic_init - register asic specific callbacks
+ *
+ * @rdev: radeon device pointer
+ *
+ * Registers the appropriate asic specific callbacks for each
+ * chip family.  Also sets other asics specific info like the number
+ * of crtcs and the register aperture accessors (all asics).
+ * Returns 0 for success.
+ */
 int radeon_asic_init(struct radeon_device *rdev)
 {
 	radeon_register_accessor_init(rdev);
-- 
1.7.7.5

[PATCH 05/10] drm/radeon: document radeon_fence.c (v2)

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

Adds documentation to most of the functions in
radeon_fence.c

v2: address Christian's comments:
- split common concept description into it's own comment
- fix description of intr parameter
- Improve description of -EDEADLK error

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/radeon_fence.c |  238 +++++++++++++++++++++++++++++++++
 1 files changed, 238 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_fence.c b/drivers/gpu/drm/radeon/radeon_fence.c
index 67f6fa9..32284e7 100644
--- a/drivers/gpu/drm/radeon/radeon_fence.c
+++ b/drivers/gpu/drm/radeon/radeon_fence.c
@@ -40,6 +40,26 @@
 #include "radeon.h"
 #include "radeon_trace.h"
 
+/*
+ * Fences
+ * Fences mark an event in the GPUs pipeline and are used
+ * for GPU/CPU synchronization.  When the fence is written,
+ * it is expected that all buffers associated with that fence
+ * are no longer in use by the associated ring on the GPU and
+ * that the the relevant GPU caches have been flushed.  Whether
+ * we use a scratch register or memory location depends on the asic
+ * and whether writeback is enabled.
+ */
+
+/**
+ * radeon_fence_write - write a fence value
+ *
+ * @rdev: radeon_device pointer
+ * @seq: sequence number to write
+ * @ring: ring index the fence is associated with
+ *
+ * Writes a fence value to memory or a scratch register (all asics).
+ */
 static void radeon_fence_write(struct radeon_device *rdev, u32 seq, int ring)
 {
 	if (rdev->wb.enabled) {
@@ -49,6 +69,15 @@ static void radeon_fence_write(struct radeon_device *rdev, u32 seq, int ring)
 	}
 }
 
+/**
+ * radeon_fence_read - read a fence value
+ *
+ * @rdev: radeon_device pointer
+ * @ring: ring index the fence is associated with
+ *
+ * Reads a fence value from memory or a scratch register (all asics).
+ * Returns the value of the fence read from memory or register.
+ */
 static u32 radeon_fence_read(struct radeon_device *rdev, int ring)
 {
 	u32 seq = 0;
@@ -61,6 +90,16 @@ static u32 radeon_fence_read(struct radeon_device *rdev, int ring)
 	return seq;
 }
 
+/**
+ * radeon_fence_emit - emit a fence on the requested ring
+ *
+ * @rdev: radeon_device pointer
+ * @fence: radeon fence object
+ * @ring: ring index the fence is associated with
+ *
+ * Emits a fence command on the requested ring (all asics).
+ * Returns 0 on success, -ENOMEM on failure.
+ */
 int radeon_fence_emit(struct radeon_device *rdev,
 		      struct radeon_fence **fence,
 		      int ring)
@@ -79,6 +118,15 @@ int radeon_fence_emit(struct radeon_device *rdev,
 	return 0;
 }
 
+/**
+ * radeon_fence_process - process a fence
+ *
+ * @rdev: radeon_device pointer
+ * @ring: ring index the fence is associated with
+ *
+ * Checks the current fence value and wakes the fence queue
+ * if the sequence number has increased (all asics).
+ */
 void radeon_fence_process(struct radeon_device *rdev, int ring)
 {
 	uint64_t seq, last_seq;
@@ -139,6 +187,13 @@ void radeon_fence_process(struct radeon_device *rdev, int ring)
 	}
 }
 
+/**
+ * radeon_fence_destroy - destroy a fence
+ *
+ * @kref: fence kref
+ *
+ * Frees the fence object (all asics).
+ */
 static void radeon_fence_destroy(struct kref *kref)
 {
 	struct radeon_fence *fence;
@@ -147,6 +202,20 @@ static void radeon_fence_destroy(struct kref *kref)
 	kfree(fence);
 }
 
+/**
+ * radeon_fence_seq_signaled - check if a fence sequeuce number has signaled
+ *
+ * @rdev: radeon device pointer
+ * @seq: sequence number
+ * @ring: ring index the fence is associated with
+ *
+ * Check if the last singled fence sequnce number is >= the requested
+ * sequence number (all asics).
+ * Returns true if the fence has signaled (current fence value
+ * is >= requested value) or false if it has not (current fence
+ * value is < the requested value.  Helper function for
+ * radeon_fence_signaled().
+ */
 static bool radeon_fence_seq_signaled(struct radeon_device *rdev,
 				      u64 seq, unsigned ring)
 {
@@ -161,6 +230,14 @@ static bool radeon_fence_seq_signaled(struct radeon_device *rdev,
 	return false;
 }
 
+/**
+ * radeon_fence_signaled - check if a fence has signaled
+ *
+ * @fence: radeon fence object
+ *
+ * Check if the requested fence has signaled (all asics).
+ * Returns true if the fence has signaled or false if it has not.
+ */
 bool radeon_fence_signaled(struct radeon_fence *fence)
 {
 	if (!fence) {
@@ -176,6 +253,24 @@ bool radeon_fence_signaled(struct radeon_fence *fence)
 	return false;
 }
 
+/**
+ * radeon_fence_wait_seq - wait for a specific sequence number
+ *
+ * @rdev: radeon device pointer
+ * @target_seq: sequence number we want to wait for
+ * @ring: ring index the fence is associated with
+ * @intr: use interruptable sleep
+ * @lock_ring: whether the ring should be locked or not
+ *
+ * Wait for the requested sequence number to be written (all asics).
+ * @intr selects whether to use interruptable (true) or non-interruptable
+ * (false) sleep when waiting for the sequence number.  Helper function
+ * for radeon_fence_wait(), et al.
+ * Returns 0 if the sequence number has passed, error for all other cases.
+ * -EDEADLK is returned when a GPU lockup has been detected and the ring is
+ * marked as not ready so no further jobs get scheduled until a successful
+ * reset.
+ */
 static int radeon_fence_wait_seq(struct radeon_device *rdev, u64 target_seq,
 				 unsigned ring, bool intr, bool lock_ring)
 {
@@ -271,6 +366,17 @@ static int radeon_fence_wait_seq(struct radeon_device *rdev, u64 target_seq,
 	return 0;
 }
 
+/**
+ * radeon_fence_wait - wait for a fence to signal
+ *
+ * @fence: radeon fence object
+ * @intr: use interruptable sleep
+ *
+ * Wait for the requested fence to signal (all asics).
+ * @intr selects whether to use interruptable (true) or non-interruptable
+ * (false) sleep when waiting for the fence.
+ * Returns 0 if the fence has passed, error for all other cases.
+ */
 int radeon_fence_wait(struct radeon_fence *fence, bool intr)
 {
 	int r;
@@ -301,6 +407,20 @@ static bool radeon_fence_any_seq_signaled(struct radeon_device *rdev, u64 *seq)
 	return false;
 }
 
+/**
+ * radeon_fence_wait_any_seq - wait for a sequence number on any ring
+ *
+ * @rdev: radeon device pointer
+ * @target_seq: sequence number(s) we want to wait for
+ * @intr: use interruptable sleep
+ *
+ * Wait for the requested sequence number(s) to be written by any ring
+ * (all asics).  Sequnce number array is indexed by ring id.
+ * @intr selects whether to use interruptable (true) or non-interruptable
+ * (false) sleep when waiting for the sequence number.  Helper function
+ * for radeon_fence_wait_any(), et al.
+ * Returns 0 if the sequence number has passed, error for all other cases.
+ */
 static int radeon_fence_wait_any_seq(struct radeon_device *rdev,
 				     u64 *target_seq, bool intr)
 {
@@ -410,6 +530,19 @@ static int radeon_fence_wait_any_seq(struct radeon_device *rdev,
 	return 0;
 }
 
+/**
+ * radeon_fence_wait_any - wait for a fence to signal on any ring
+ *
+ * @rdev: radeon device pointer
+ * @fences: radeon fence object(s)
+ * @intr: use interruptable sleep
+ *
+ * Wait for any requested fence to signal (all asics).  Fence
+ * array is indexed by ring id.  @intr selects whether to use
+ * interruptable (true) or non-interruptable (false) sleep when
+ * waiting for the fences. Used by the suballocator.
+ * Returns 0 if any fence has passed, error for all other cases.
+ */
 int radeon_fence_wait_any(struct radeon_device *rdev,
 			  struct radeon_fence **fences,
 			  bool intr)
@@ -440,6 +573,15 @@ int radeon_fence_wait_any(struct radeon_device *rdev,
 	return 0;
 }
 
+/**
+ * radeon_fence_wait_next_locked - wait for the next fence to signal
+ *
+ * @rdev: radeon device pointer
+ * @ring: ring index the fence is associated with
+ *
+ * Wait for the next fence on the requested ring to signal (all asics).
+ * Returns 0 if the next fence has passed, error for all other cases.
+ */
 int radeon_fence_wait_next_locked(struct radeon_device *rdev, int ring)
 {
 	uint64_t seq;
@@ -457,6 +599,15 @@ int radeon_fence_wait_next_locked(struct radeon_device *rdev, int ring)
 	return radeon_fence_wait_seq(rdev, seq, ring, false, false);
 }
 
+/**
+ * radeon_fence_wait_empty_locked - wait for all fences to signal
+ *
+ * @rdev: radeon device pointer
+ * @ring: ring index the fence is associated with
+ *
+ * Wait for all fences on the requested ring to signal (all asics).
+ * Returns 0 if the fences have passed, error for all other cases.
+ */
 int radeon_fence_wait_empty_locked(struct radeon_device *rdev, int ring)
 {
 	/* We are not protected by ring lock when reading current seq
@@ -468,12 +619,27 @@ int radeon_fence_wait_empty_locked(struct radeon_device *rdev, int ring)
 				     ring, false, false);
 }
 
+/**
+ * radeon_fence_ref - take a ref on a fence
+ *
+ * @fence: radeon fence object
+ *
+ * Take a reference on a fence (all asics).
+ * Returns the fence.
+ */
 struct radeon_fence *radeon_fence_ref(struct radeon_fence *fence)
 {
 	kref_get(&fence->kref);
 	return fence;
 }
 
+/**
+ * radeon_fence_unref - remove a ref on a fence
+ *
+ * @fence: radeon fence object
+ *
+ * Remove a reference on a fence (all asics).
+ */
 void radeon_fence_unref(struct radeon_fence **fence)
 {
 	struct radeon_fence *tmp = *fence;
@@ -484,6 +650,16 @@ void radeon_fence_unref(struct radeon_fence **fence)
 	}
 }
 
+/**
+ * radeon_fence_count_emitted - get the count of emitted fences
+ *
+ * @rdev: radeon device pointer
+ * @ring: ring index the fence is associated with
+ *
+ * Get the number of fences emitted on the requested ring (all asics).
+ * Returns the number of emitted fences on the ring.  Used by the
+ * dynpm code to ring track activity.
+ */
 unsigned radeon_fence_count_emitted(struct radeon_device *rdev, int ring)
 {
 	uint64_t emitted;
@@ -501,6 +677,17 @@ unsigned radeon_fence_count_emitted(struct radeon_device *rdev, int ring)
 	return (unsigned)emitted;
 }
 
+/**
+ * radeon_fence_need_sync - do we need a semaphore
+ *
+ * @fence: radeon fence object
+ * @dst_ring: which ring to check against
+ *
+ * Check if the fence needs to be synced against another ring
+ * (all asics).  If so, we need to emit a semaphore.
+ * Returns true if we need to sync with another ring, false if
+ * not.
+ */
 bool radeon_fence_need_sync(struct radeon_fence *fence, int dst_ring)
 {
 	struct radeon_fence_driver *fdrv;
@@ -522,6 +709,15 @@ bool radeon_fence_need_sync(struct radeon_fence *fence, int dst_ring)
 	return true;
 }
 
+/**
+ * radeon_fence_note_sync - record the sync point
+ *
+ * @fence: radeon fence object
+ * @dst_ring: which ring to check against
+ *
+ * Note the sequence number at which point the fence will
+ * be synced with the requested ring (all asics).
+ */
 void radeon_fence_note_sync(struct radeon_fence *fence, int dst_ring)
 {
 	struct radeon_fence_driver *dst, *src;
@@ -546,6 +742,18 @@ void radeon_fence_note_sync(struct radeon_fence *fence, int dst_ring)
 	}
 }
 
+/**
+ * radeon_fence_driver_start_ring - make the fence driver
+ * ready for use on the requested ring.
+ *
+ * @rdev: radeon device pointer
+ * @ring: ring index to start the fence driver on
+ *
+ * Make the fence driver ready for processing (all asics).
+ * Not all asics have all rings, so each asic will only
+ * start the fence driver on the rings it has.
+ * Returns 0 for success, errors for failure.
+ */
 int radeon_fence_driver_start_ring(struct radeon_device *rdev, int ring)
 {
 	uint64_t index;
@@ -574,6 +782,16 @@ int radeon_fence_driver_start_ring(struct radeon_device *rdev, int ring)
 	return 0;
 }
 
+/**
+ * radeon_fence_driver_init_ring - init the fence driver
+ * for the requested ring.
+ *
+ * @rdev: radeon device pointer
+ * @ring: ring index to start the fence driver on
+ *
+ * Init the fence driver for the requested ring (all asics).
+ * Helper function for radeon_fence_driver_init().
+ */
 static void radeon_fence_driver_init_ring(struct radeon_device *rdev, int ring)
 {
 	int i;
@@ -588,6 +806,18 @@ static void radeon_fence_driver_init_ring(struct radeon_device *rdev, int ring)
 	rdev->fence_drv[ring].initialized = false;
 }
 
+/**
+ * radeon_fence_driver_init - init the fence driver
+ * for all possible rings.
+ *
+ * @rdev: radeon device pointer
+ *
+ * Init the fence driver for all possible rings (all asics).
+ * Not all asics have all rings, so each asic will only
+ * start the fence driver on the rings it has using
+ * radeon_fence_driver_start_ring().
+ * Returns 0 for success.
+ */
 int radeon_fence_driver_init(struct radeon_device *rdev)
 {
 	int ring;
@@ -602,6 +832,14 @@ int radeon_fence_driver_init(struct radeon_device *rdev)
 	return 0;
 }
 
+/**
+ * radeon_fence_driver_fini - tear down the fence driver
+ * for all possible rings.
+ *
+ * @rdev: radeon device pointer
+ *
+ * Tear down the fence driver for all possible rings (all asics).
+ */
 void radeon_fence_driver_fini(struct radeon_device *rdev)
 {
 	int ring;
-- 
1.7.7.5

[PATCH 06/10] drm/radeon: document radeon_ring.c (v2)

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

Adds documentation to most of the functions in
radeon_ring.c

v2: adjust per Christian's suggestions

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/radeon_ring.c |  216 +++++++++++++++++++++++++++++++++-
 1 files changed, 213 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_ring.c b/drivers/gpu/drm/radeon/radeon_ring.c
index 0826e77..cec80fa 100644
--- a/drivers/gpu/drm/radeon/radeon_ring.c
+++ b/drivers/gpu/drm/radeon/radeon_ring.c
@@ -35,10 +35,28 @@
 #include "atom.h"
 
 /*
- * IB.
+ * IB
+ * IBs (Indirect Buffers) and areas of GPU accessible memory where
+ * commands are stored.  You can put a pointer to the IB in the
+ * command ring and the hw will fetch the commands from the IB
+ * and execute them.  Generally userspace acceleration drivers
+ * produce command buffers which are send to the kernel and
+ * put in IBs for execution by the requested ring.
  */
 int radeon_debugfs_sa_init(struct radeon_device *rdev);
 
+/**
+ * radeon_ib_get - request an IB (Indirect Buffer)
+ *
+ * @rdev: radeon_device pointer
+ * @ring: ring index the IB is associated with
+ * @ib: IB object returned
+ * @size: requested IB size
+ *
+ * Request an IB (all asics).  IBs are allocated using the
+ * suballocator.
+ * Returns 0 on success, error on failure.
+ */
 int radeon_ib_get(struct radeon_device *rdev, int ring,
 		  struct radeon_ib *ib, unsigned size)
 {
@@ -67,6 +85,14 @@ int radeon_ib_get(struct radeon_device *rdev, int ring,
 	return 0;
 }
 
+/**
+ * radeon_ib_free - free an IB (Indirect Buffer)
+ *
+ * @rdev: radeon_device pointer
+ * @ib: IB object to free
+ *
+ * Free an IB (all asics).
+ */
 void radeon_ib_free(struct radeon_device *rdev, struct radeon_ib *ib)
 {
 	radeon_semaphore_free(rdev, &ib->semaphore, ib->fence);
@@ -74,6 +100,15 @@ void radeon_ib_free(struct radeon_device *rdev, struct radeon_ib *ib)
 	radeon_fence_unref(&ib->fence);
 }
 
+/**
+ * radeon_ib_schedule - schedule an IB (Indirect Buffer) on the ring
+ *
+ * @rdev: radeon_device pointer
+ * @ib: IB object to schedule
+ *
+ * Schedule an IB on the associated ring (all asics).
+ * Returns 0 on success, error on failure.
+ */
 int radeon_ib_schedule(struct radeon_device *rdev, struct radeon_ib *ib)
 {
 	struct radeon_ring *ring = &rdev->ring[ib->ring];
@@ -116,6 +151,15 @@ int radeon_ib_schedule(struct radeon_device *rdev, struct radeon_ib *ib)
 	return 0;
 }
 
+/**
+ * radeon_ib_pool_init - Init the IB (Indirect Buffer) pool
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Initialize the suballocator to manage a pool of memory
+ * for use as IBs (all asics).
+ * Returns 0 on success, error on failure.
+ */
 int radeon_ib_pool_init(struct radeon_device *rdev)
 {
 	int r;
@@ -136,6 +180,14 @@ int radeon_ib_pool_init(struct radeon_device *rdev)
 	return 0;
 }
 
+/**
+ * radeon_ib_pool_fini - Free the IB (Indirect Buffer) pool
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Tear down the suballocator managing the pool of memory
+ * for use as IBs (all asics).
+ */
 void radeon_ib_pool_fini(struct radeon_device *rdev)
 {
 	if (rdev->ib_pool_ready) {
@@ -144,16 +196,46 @@ void radeon_ib_pool_fini(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * radeon_ib_pool_start - Start the IB (Indirect Buffer) pool
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Start the suballocator that manages pool of memory
+ * used for IBs (all asics).  Used to start the IB pool on
+ * device startup and resume.
+ * Returns 0 on success, error on failure.
+ */
 int radeon_ib_pool_start(struct radeon_device *rdev)
 {
 	return radeon_sa_bo_manager_start(rdev, &rdev->ring_tmp_bo);
 }
 
+/**
+ * radeon_ib_pool_suspend - Suspend the IB (Indirect Buffer) pool
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Stop the suballocator that manages the pool of memory
+ * used as IBs (all asics).  Used to stop the IB pool on
+ * device suspend.
+ * Returns 0 on success, error on failure.
+ */
 int radeon_ib_pool_suspend(struct radeon_device *rdev)
 {
 	return radeon_sa_bo_manager_suspend(rdev, &rdev->ring_tmp_bo);
 }
 
+/**
+ * radeon_ib_ring_tests - Test IBs (Indirect Buffer) on all
+ * relevant rings
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Execute a test IB on the rings (all asics).  Used to test
+ * if IBs are working on the rings at device startup and resume.
+ * Returns 0 on success, error on failure.
+ */
 int radeon_ib_ring_tests(struct radeon_device *rdev)
 {
 	unsigned i;
@@ -185,10 +267,28 @@ int radeon_ib_ring_tests(struct radeon_device *rdev)
 }
 
 /*
- * Ring.
+ * Rings
+ * Most engines on the GPU are fed via ring buffers.  Ring
+ * buffers are areas of GPU accessible memory that the host
+ * writes commands into and the GPU reads commands out of.
+ * There is a rptr (read pointer) that determines where the
+ * GPU is currently reading, and a wptr (write pointer)
+ * which determines where the host has written.  When the
+ * pointers are equal, the ring is idle.  When the host
+ * writes commands to the ring buffer, it increments the
+ * wptr.  The GPU then starts fetching commands and executes
+ * them until the pointers are equal again.
  */
 int radeon_debugfs_ring_init(struct radeon_device *rdev, struct radeon_ring *ring);
 
+/**
+ * radeon_ring_write - write a value to the ring
+ *
+ * @ring: radeon_ring structure holding ring information
+ * @v: dword (dw) value to write
+ *
+ * Write a value to the requested ring buffer (all asics).
+ */
 void radeon_ring_write(struct radeon_ring *ring, uint32_t v)
 {
 #if DRM_DEBUG_CODE
@@ -202,6 +302,15 @@ void radeon_ring_write(struct radeon_ring *ring, uint32_t v)
 	ring->ring_free_dw--;
 }
 
+/**
+ * radeon_ring_index - look up the index of the requested ring
+ *
+ * @rdev: radeon_device pointer
+ * @ring: radeon_ring structure holding ring information
+ *
+ * Look up the index of the requested ring object (all asics).
+ * Returns the index of the requested ring object.
+ */
 int radeon_ring_index(struct radeon_device *rdev, struct radeon_ring *ring)
 {
 	/* r1xx-r5xx only has CP ring */
@@ -217,6 +326,14 @@ int radeon_ring_index(struct radeon_device *rdev, struct radeon_ring *ring)
 	return RADEON_RING_TYPE_GFX_INDEX;
 }
 
+/**
+ * radeon_ring_free_size - update the free size
+ *
+ * @rdev: radeon_device pointer
+ * @ring: radeon_ring structure holding ring information
+ *
+ * Update the free dw slots in the ring buffer (all asics).
+ */
 void radeon_ring_free_size(struct radeon_device *rdev, struct radeon_ring *ring)
 {
 	u32 rptr;
@@ -235,7 +352,16 @@ void radeon_ring_free_size(struct radeon_device *rdev, struct radeon_ring *ring)
 	}
 }
 
-
+/**
+ * radeon_ring_alloc - allocate space on the ring buffer
+ *
+ * @rdev: radeon_device pointer
+ * @ring: radeon_ring structure holding ring information
+ * @ndw: number of dwords to allocate in the ring buffer
+ *
+ * Allocate @ndw dwords in the ring buffer (all asics).
+ * Returns 0 on success, error on failure.
+ */
 int radeon_ring_alloc(struct radeon_device *rdev, struct radeon_ring *ring, unsigned ndw)
 {
 	int r;
@@ -257,6 +383,17 @@ int radeon_ring_alloc(struct radeon_device *rdev, struct radeon_ring *ring, unsi
 	return 0;
 }
 
+/**
+ * radeon_ring_lock - lock the ring and allocate space on it
+ *
+ * @rdev: radeon_device pointer
+ * @ring: radeon_ring structure holding ring information
+ * @ndw: number of dwords to allocate in the ring buffer
+ *
+ * Lock the ring and allocate @ndw dwords in the ring buffer
+ * (all asics).
+ * Returns 0 on success, error on failure.
+ */
 int radeon_ring_lock(struct radeon_device *rdev, struct radeon_ring *ring, unsigned ndw)
 {
 	int r;
@@ -270,6 +407,16 @@ int radeon_ring_lock(struct radeon_device *rdev, struct radeon_ring *ring, unsig
 	return 0;
 }
 
+/**
+ * radeon_ring_commit - tell the GPU to execute the new
+ * commands on the ring buffer
+ *
+ * @rdev: radeon_device pointer
+ * @ring: radeon_ring structure holding ring information
+ *
+ * Update the wptr (write pointer) to tell the GPU to
+ * execute new commands on the ring buffer (all asics).
+ */
 void radeon_ring_commit(struct radeon_device *rdev, struct radeon_ring *ring)
 {
 	unsigned count_dw_pad;
@@ -286,23 +433,55 @@ void radeon_ring_commit(struct radeon_device *rdev, struct radeon_ring *ring)
 	(void)RREG32(ring->wptr_reg);
 }
 
+/**
+ * radeon_ring_unlock_commit - tell the GPU to execute the new
+ * commands on the ring buffer and unlock it
+ *
+ * @rdev: radeon_device pointer
+ * @ring: radeon_ring structure holding ring information
+ *
+ * Call radeon_ring_commit() then unlock the ring (all asics).
+ */
 void radeon_ring_unlock_commit(struct radeon_device *rdev, struct radeon_ring *ring)
 {
 	radeon_ring_commit(rdev, ring);
 	mutex_unlock(&rdev->ring_lock);
 }
 
+/**
+ * radeon_ring_undo - reset the wptr
+ *
+ * @ring: radeon_ring structure holding ring information
+ *
+ * Reset the driver's copy of the wtpr (all asics).
+ */
 void radeon_ring_undo(struct radeon_ring *ring)
 {
 	ring->wptr = ring->wptr_old;
 }
 
+/**
+ * radeon_ring_unlock_undo - reset the wptr and unlock the ring
+ *
+ * @ring: radeon_ring structure holding ring information
+ *
+ * Call radeon_ring_undo() then unlock the ring (all asics).
+ */
 void radeon_ring_unlock_undo(struct radeon_device *rdev, struct radeon_ring *ring)
 {
 	radeon_ring_undo(ring);
 	mutex_unlock(&rdev->ring_lock);
 }
 
+/**
+ * radeon_ring_force_activity - add some nop packets to the ring
+ *
+ * @rdev: radeon_device pointer
+ * @ring: radeon_ring structure holding ring information
+ *
+ * Add some nop packets to the ring to force activity (all asics).
+ * Used for lockup detection to see if the rptr is advancing.
+ */
 void radeon_ring_force_activity(struct radeon_device *rdev, struct radeon_ring *ring)
 {
 	int r;
@@ -317,6 +496,13 @@ void radeon_ring_force_activity(struct radeon_device *rdev, struct radeon_ring *
 	}
 }
 
+/**
+ * radeon_ring_force_activity - update lockup variables
+ *
+ * @ring: radeon_ring structure holding ring information
+ *
+ * Update the last rptr value and timestamp (all asics).
+ */
 void radeon_ring_lockup_update(struct radeon_ring *ring)
 {
 	ring->last_rptr = ring->rptr;
@@ -370,6 +556,22 @@ bool radeon_ring_test_lockup(struct radeon_device *rdev, struct radeon_ring *rin
 	return false;
 }
 
+/**
+ * radeon_ring_init - init driver ring struct.
+ *
+ * @rdev: radeon_device pointer
+ * @ring: radeon_ring structure holding ring information
+ * @ring_size: size of the ring
+ * @rptr_offs: offset of the rptr writeback location in the WB buffer
+ * @rptr_reg: MMIO offset of the rptr register
+ * @wptr_reg: MMIO offset of the wptr register
+ * @ptr_reg_shift: bit offset of the rptr/wptr values
+ * @ptr_reg_mask: bit mask of the rptr/wptr values
+ * @nop: nop packet for this ring
+ *
+ * Initialize the driver information for the selected ring (all asics).
+ * Returns 0 on success, error on failure.
+ */
 int radeon_ring_init(struct radeon_device *rdev, struct radeon_ring *ring, unsigned ring_size,
 		     unsigned rptr_offs, unsigned rptr_reg, unsigned wptr_reg,
 		     u32 ptr_reg_shift, u32 ptr_reg_mask, u32 nop)
@@ -418,6 +620,14 @@ int radeon_ring_init(struct radeon_device *rdev, struct radeon_ring *ring, unsig
 	return 0;
 }
 
+/**
+ * radeon_ring_fini - tear down the driver ring struct.
+ *
+ * @rdev: radeon_device pointer
+ * @ring: radeon_ring structure holding ring information
+ *
+ * Tear down the driver information for the selected ring (all asics).
+ */
 void radeon_ring_fini(struct radeon_device *rdev, struct radeon_ring *ring)
 {
 	int r;
-- 
1.7.7.5

[PATCH 07/10] drm/radeon: document non-VM functions in radeon_gart.c (v2)

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

Document the non-VM functions in radeon_gart.c

v2: adjust per Christian's suggestions

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/radeon_gart.c |  125 +++++++++++++++++++++++++++++++++-
 1 files changed, 122 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_gart.c b/drivers/gpu/drm/radeon/radeon_gart.c
index 8c44d1d..f6a9dab 100644
--- a/drivers/gpu/drm/radeon/radeon_gart.c
+++ b/drivers/gpu/drm/radeon/radeon_gart.c
@@ -31,8 +31,38 @@
 #include "radeon_reg.h"
 
 /*
+ * GART
+ * The GART (Graphics Aperture Remapping Table) is an aperture
+ * in the GPU's address space.  System pages can be mapped into
+ * the aperture and look like contiguous pages from the GPU's
+ * perspective.  A page table maps the pages in the aperture
+ * to the actual backing pages in system memory.
+ *
+ * Radeon GPUs support both an internal GART, as described above,
+ * and AGP.  AGP works similarly, but the GART table is configured
+ * and maintained by the northbridge rather than the driver.
+ * Radeon hw has a separate AGP aperture that is programmed to
+ * point to the AGP aperture provided by the northbridge and the
+ * requests are passed through to the northbridge aperture.
+ * Both AGP and internal GART can be used at the same time, however
+ * that is not currently supported by the driver.
+ *
+ * This file handles the common internal GART management.
+ */
+
+/*
  * Common GART table functions.
  */
+/**
+ * radeon_gart_table_ram_alloc - allocate system ram for gart page table
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Allocate system memory for GART page table
+ * (r1xx-r3xx, non-pcie r4xx, rs400).  These asics require the
+ * gart table to be in system memory.
+ * Returns 0 for success, -ENOMEM for failure.
+ */
 int radeon_gart_table_ram_alloc(struct radeon_device *rdev)
 {
 	void *ptr;
@@ -54,6 +84,15 @@ int radeon_gart_table_ram_alloc(struct radeon_device *rdev)
 	return 0;
 }
 
+/**
+ * radeon_gart_table_ram_free - free system ram for gart page table
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Free system memory for GART page table
+ * (r1xx-r3xx, non-pcie r4xx, rs400).  These asics require the
+ * gart table to be in system memory.
+ */
 void radeon_gart_table_ram_free(struct radeon_device *rdev)
 {
 	if (rdev->gart.ptr == NULL) {
@@ -73,6 +112,16 @@ void radeon_gart_table_ram_free(struct radeon_device *rdev)
 	rdev->gart.table_addr = 0;
 }
 
+/**
+ * radeon_gart_table_vram_alloc - allocate vram for gart page table
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Allocate video memory for GART page table
+ * (pcie r4xx, r5xx+).  These asics require the
+ * gart table to be in video memory.
+ * Returns 0 for success, error for failure.
+ */
 int radeon_gart_table_vram_alloc(struct radeon_device *rdev)
 {
 	int r;
@@ -88,6 +137,16 @@ int radeon_gart_table_vram_alloc(struct radeon_device *rdev)
 	return 0;
 }
 
+/**
+ * radeon_gart_table_vram_pin - pin gart page table in vram
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Pin the GART page table in vram so it will not be moved
+ * by the memory manager (pcie r4xx, r5xx+).  These asics require the
+ * gart table to be in video memory.
+ * Returns 0 for success, error for failure.
+ */
 int radeon_gart_table_vram_pin(struct radeon_device *rdev)
 {
 	uint64_t gpu_addr;
@@ -110,6 +169,14 @@ int radeon_gart_table_vram_pin(struct radeon_device *rdev)
 	return r;
 }
 
+/**
+ * radeon_gart_table_vram_unpin - unpin gart page table in vram
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Unpin the GART page table in vram (pcie r4xx, r5xx+).
+ * These asics require the gart table to be in video memory.
+ */
 void radeon_gart_table_vram_unpin(struct radeon_device *rdev)
 {
 	int r;
@@ -126,6 +193,15 @@ void radeon_gart_table_vram_unpin(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * radeon_gart_table_vram_free - free gart page table vram
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Free the video memory used for the GART page table
+ * (pcie r4xx, r5xx+).  These asics require the gart table to
+ * be in video memory.
+ */
 void radeon_gart_table_vram_free(struct radeon_device *rdev)
 {
 	if (rdev->gart.robj == NULL) {
@@ -135,12 +211,19 @@ void radeon_gart_table_vram_free(struct radeon_device *rdev)
 	radeon_bo_unref(&rdev->gart.robj);
 }
 
-
-
-
 /*
  * Common gart functions.
  */
+/**
+ * radeon_gart_unbind - unbind pages from the gart page table
+ *
+ * @rdev: radeon_device pointer
+ * @offset: offset into the GPU's gart aperture
+ * @pages: number of pages to unbind
+ *
+ * Unbinds the requested pages from the gart page table and
+ * replaces them with the dummy page (all asics).
+ */
 void radeon_gart_unbind(struct radeon_device *rdev, unsigned offset,
 			int pages)
 {
@@ -172,6 +255,19 @@ void radeon_gart_unbind(struct radeon_device *rdev, unsigned offset,
 	radeon_gart_tlb_flush(rdev);
 }
 
+/**
+ * radeon_gart_bind - bind pages into the gart page table
+ *
+ * @rdev: radeon_device pointer
+ * @offset: offset into the GPU's gart aperture
+ * @pages: number of pages to bind
+ * @pagelist: pages to bind
+ * @dma_addr: DMA addresses of pages
+ *
+ * Binds the requested pages to the gart page table
+ * (all asics).
+ * Returns 0 for success, -EINVAL for failure.
+ */
 int radeon_gart_bind(struct radeon_device *rdev, unsigned offset,
 		     int pages, struct page **pagelist, dma_addr_t *dma_addr)
 {
@@ -203,6 +299,14 @@ int radeon_gart_bind(struct radeon_device *rdev, unsigned offset,
 	return 0;
 }
 
+/**
+ * radeon_gart_restore - bind all pages in the gart page table
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Binds all pages in the gart page table (all asics).
+ * Used to rebuild the gart table on device startup or resume.
+ */
 void radeon_gart_restore(struct radeon_device *rdev)
 {
 	int i, j, t;
@@ -222,6 +326,14 @@ void radeon_gart_restore(struct radeon_device *rdev)
 	radeon_gart_tlb_flush(rdev);
 }
 
+/**
+ * radeon_gart_init - init the driver info for managing the gart
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Allocate the dummy page and init the gart driver info (all asics).
+ * Returns 0 for success, error for failure.
+ */
 int radeon_gart_init(struct radeon_device *rdev)
 {
 	int r, i;
@@ -262,6 +374,13 @@ int radeon_gart_init(struct radeon_device *rdev)
 	return 0;
 }
 
+/**
+ * radeon_gart_fini - tear down the driver info for managing the gart
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Tear down the gart driver info and free the dummy page (all asics).
+ */
 void radeon_gart_fini(struct radeon_device *rdev)
 {
 	if (rdev->gart.pages && rdev->gart.pages_addr && rdev->gart.ready) {
-- 
1.7.7.5

[PATCH 08/10] drm/radeon: document VM functions in radeon_gart.c (v2)

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

Document the VM functions in radeon_gart.c

v2: adjust per Christian's suggestions

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/radeon_gart.c |  159 ++++++++++++++++++++++++++++++++++
 1 files changed, 159 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_gart.c b/drivers/gpu/drm/radeon/radeon_gart.c
index f6a9dab..2b842ba 100644
--- a/drivers/gpu/drm/radeon/radeon_gart.c
+++ b/drivers/gpu/drm/radeon/radeon_gart.c
@@ -397,10 +397,38 @@ void radeon_gart_fini(struct radeon_device *rdev)
 }
 
 /*
+ * GPUVM
+ * GPUVM is similar to the legacy gart on older asics, however
+ * rather than there being a single global gart table
+ * for the entire GPU, there are multiple VM page tables active
+ * at any given time.  The VM page tables can contain a mix
+ * vram pages and system memory pages and system memory pages
+ * can be mapped as snooped (cached system pages) or unsnooped
+ * (uncached system pages).
+ * Each VM has an ID associated with it and there is a page table
+ * associated with each VMID.  When execting a command buffer,
+ * the kernel tells the the ring what VMID to use for that command
+ * buffer.  VMIDs are allocated dynamically as commands are submitted.
+ * The userspace drivers maintain their own address space and the kernel
+ * sets up their pages tables accordingly when they submit their
+ * command buffers and a VMID is assigned.
+ * Cayman/Trinity support up to 8 active VMs at any given time;
+ * SI supports 16.
+ */
+
+/*
  * vm helpers
  *
  * TODO bind a default page at vm initialization for default address
  */
+/**
+ * radeon_vm_manager_init - init the vm manager
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Init the vm manager (cayman+).
+ * Returns 0 for success, error for failure.
+ */
 int radeon_vm_manager_init(struct radeon_device *rdev)
 {
 	int r;
@@ -426,6 +454,16 @@ int radeon_vm_manager_init(struct radeon_device *rdev)
 }
 
 /* global mutex must be lock */
+/**
+ * radeon_vm_unbind_locked - unbind a specific vm
+ *
+ * @rdev: radeon_device pointer
+ * @vm: vm to unbind
+ *
+ * Unbind the requested vm (cayman+).
+ * Wait for use of the VM to finish, then unbind the page table,
+ * and free the page table memory.
+ */
 static void radeon_vm_unbind_locked(struct radeon_device *rdev,
 				    struct radeon_vm *vm)
 {
@@ -454,6 +492,13 @@ static void radeon_vm_unbind_locked(struct radeon_device *rdev,
 	}
 }
 
+/**
+ * radeon_vm_manager_fini - tear down the vm manager
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Tear down the VM manager (cayman+).
+ */
 void radeon_vm_manager_fini(struct radeon_device *rdev)
 {
 	if (rdev->vm_manager.sa_manager.bo == NULL)
@@ -464,6 +509,14 @@ void radeon_vm_manager_fini(struct radeon_device *rdev)
 	rdev->vm_manager.enabled = false;
 }
 
+/**
+ * radeon_vm_manager_start - start the vm manager
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Start the suballocator instance used for VM (cayman+).
+ * Returns 0 for success, error for failure.
+ */
 int radeon_vm_manager_start(struct radeon_device *rdev)
 {
 	if (rdev->vm_manager.sa_manager.bo == NULL) {
@@ -472,6 +525,15 @@ int radeon_vm_manager_start(struct radeon_device *rdev)
 	return radeon_sa_bo_manager_start(rdev, &rdev->vm_manager.sa_manager);
 }
 
+/**
+ * radeon_vm_manager_suspend - suspend the vm manager
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Unbind all the VM page tables and suspend the suballocator
+ * instance used for VM (cayman+).
+ * Returns 0 for success, error for failure.
+ */
 int radeon_vm_manager_suspend(struct radeon_device *rdev)
 {
 	struct radeon_vm *vm, *tmp;
@@ -487,6 +549,14 @@ int radeon_vm_manager_suspend(struct radeon_device *rdev)
 }
 
 /* global mutex must be locked */
+/**
+ * radeon_vm_unbind - locked version of unbind
+ *
+ * @rdev: radeon_device pointer
+ * @vm: vm to unbind
+ *
+ * Locked version that wraps radeon_vm_unbind_locked (cayman+).
+ */
 void radeon_vm_unbind(struct radeon_device *rdev, struct radeon_vm *vm)
 {
 	mutex_lock(&vm->mutex);
@@ -495,6 +565,18 @@ void radeon_vm_unbind(struct radeon_device *rdev, struct radeon_vm *vm)
 }
 
 /* global and local mutex must be locked */
+/**
+ * radeon_vm_bind - bind a page table to a VMID
+ *
+ * @rdev: radeon_device pointer
+ * @vm: vm to bind
+ *
+ * Bind the requested vm (cayman+).
+ * Suballocate memory for the page table, allocate a VMID
+ * and bind the page table to it, and finally start to populate
+ * the page table.
+ * Returns 0 for success, error for failure.
+ */
 int radeon_vm_bind(struct radeon_device *rdev, struct radeon_vm *vm)
 {
 	struct radeon_vm *vm_evict;
@@ -557,6 +639,20 @@ retry_id:
 }
 
 /* object have to be reserved */
+/**
+ * radeon_vm_bo_add - add a bo to a specific vm
+ *
+ * @rdev: radeon_device pointer
+ * @vm: requested vm
+ * @bo: radeon buffer object
+ * @offset: requested offset of the buffer in the VM address space
+ * @flags: attributes of pages (read/write/valid/etc.)
+ *
+ * Add @bo into the requested vm (cayman+).
+ * Add @bo to the list of bos associated with the vm and validate
+ * the offset requested within the vm address space.
+ * Returns 0 for success, error for failure.
+ */
 int radeon_vm_bo_add(struct radeon_device *rdev,
 		     struct radeon_vm *vm,
 		     struct radeon_bo *bo,
@@ -634,6 +730,17 @@ int radeon_vm_bo_add(struct radeon_device *rdev,
 	return 0;
 }
 
+/**
+ * radeon_vm_get_addr - get the physical address of the page
+ *
+ * @rdev: radeon_device pointer
+ * @mem: ttm mem
+ * @pfn: pfn
+ *
+ * Look up the physical address of the page that the pte resolves
+ * to (cayman+).
+ * Returns the physical address of the page.
+ */
 static u64 radeon_vm_get_addr(struct radeon_device *rdev,
 			      struct ttm_mem_reg *mem,
 			      unsigned pfn)
@@ -663,6 +770,17 @@ static u64 radeon_vm_get_addr(struct radeon_device *rdev,
 }
 
 /* object have to be reserved & global and local mutex must be locked */
+/**
+ * radeon_vm_bo_update_pte - map a bo into the vm page table
+ *
+ * @rdev: radeon_device pointer
+ * @vm: requested vm
+ * @bo: radeon buffer object
+ * @mem: ttm mem
+ *
+ * Fill in the page table entries for @bo (cayman+).
+ * Returns 0 for success, -EINVAL for failure.
+ */
 int radeon_vm_bo_update_pte(struct radeon_device *rdev,
 			    struct radeon_vm *vm,
 			    struct radeon_bo *bo,
@@ -711,6 +829,18 @@ int radeon_vm_bo_update_pte(struct radeon_device *rdev,
 }
 
 /* object have to be reserved */
+/**
+ * radeon_vm_bo_rmv - remove a bo to a specific vm
+ *
+ * @rdev: radeon_device pointer
+ * @vm: requested vm
+ * @bo: radeon buffer object
+ *
+ * Remove @bo from the requested vm (cayman+).
+ * Remove @bo from the list of bos associated with the vm and
+ * remove the ptes for @bo in the page table.
+ * Returns 0 for success.
+ */
 int radeon_vm_bo_rmv(struct radeon_device *rdev,
 		     struct radeon_vm *vm,
 		     struct radeon_bo *bo)
@@ -733,6 +863,15 @@ int radeon_vm_bo_rmv(struct radeon_device *rdev,
 	return 0;
 }
 
+/**
+ * radeon_vm_bo_invalidate - mark the bo as invalid
+ *
+ * @rdev: radeon_device pointer
+ * @vm: requested vm
+ * @bo: radeon buffer object
+ *
+ * Mark @bo as invalid (cayman+).
+ */
 void radeon_vm_bo_invalidate(struct radeon_device *rdev,
 			     struct radeon_bo *bo)
 {
@@ -744,6 +883,17 @@ void radeon_vm_bo_invalidate(struct radeon_device *rdev,
 	}
 }
 
+/**
+ * radeon_vm_init - initialize a vm instance
+ *
+ * @rdev: radeon_device pointer
+ * @vm: requested vm
+ *
+ * Init @vm (cayman+).
+ * Map the IB pool and any other shared objects into the VM
+ * by default as it's used by all VMs.
+ * Returns 0 for success, error for failure.
+ */
 int radeon_vm_init(struct radeon_device *rdev, struct radeon_vm *vm)
 {
 	int r;
@@ -770,6 +920,15 @@ int radeon_vm_init(struct radeon_device *rdev, struct radeon_vm *vm)
 	return r;
 }
 
+/**
+ * radeon_vm_init - tear down a vm instance
+ *
+ * @rdev: radeon_device pointer
+ * @vm: requested vm
+ *
+ * Tear down @vm (cayman+).
+ * Unbind the VM and remove all bos from the vm bo list
+ */
 void radeon_vm_fini(struct radeon_device *rdev, struct radeon_vm *vm)
 {
 	struct radeon_bo_va *bo_va, *tmp;
-- 
1.7.7.5

[PATCH 09/10] drm/radeon: start to document the functions r100.c

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

Still a lot more to do.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/r100.c |  127 ++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 124 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.c
index d06c8dd..84477dc 100644
--- a/drivers/gpu/drm/radeon/r100.c
+++ b/drivers/gpu/drm/radeon/r100.c
@@ -65,6 +65,19 @@ MODULE_FIRMWARE(FIRMWARE_R520);
 
 #include "r100_track.h"
 
+/* This files gather functions specifics to:
+ * r100,rv100,rs100,rv200,rs200,r200,rv250,rs300,rv280
+ * and others in some cases.
+ */
+
+/**
+ * r100_wait_for_vblank - vblank wait asic callback.
+ *
+ * @rdev: radeon_device pointer
+ * @crtc: crtc to wait for vblank on
+ *
+ * Wait for vblank on the requested crtc (r1xx-r4xx).
+ */
 void r100_wait_for_vblank(struct radeon_device *rdev, int crtc)
 {
 	struct radeon_crtc *radeon_crtc = rdev->mode_info.crtcs[crtc];
@@ -99,22 +112,49 @@ void r100_wait_for_vblank(struct radeon_device *rdev, int crtc)
 	}
 }
 
-/* This files gather functions specifics to:
- * r100,rv100,rs100,rv200,rs200,r200,rv250,rs300,rv280
+/**
+ * r100_pre_page_flip - pre-pageflip callback.
+ *
+ * @rdev: radeon_device pointer
+ * @crtc: crtc to prepare for pageflip on
+ *
+ * Pre-pageflip callback (r1xx-r4xx).
+ * Enables the pageflip irq (vblank irq).
  */
-
 void r100_pre_page_flip(struct radeon_device *rdev, int crtc)
 {
 	/* enable the pflip int */
 	radeon_irq_kms_pflip_irq_get(rdev, crtc);
 }
 
+/**
+ * r100_post_page_flip - pos-pageflip callback.
+ *
+ * @rdev: radeon_device pointer
+ * @crtc: crtc to cleanup pageflip on
+ *
+ * Post-pageflip callback (r1xx-r4xx).
+ * Disables the pageflip irq (vblank irq).
+ */
 void r100_post_page_flip(struct radeon_device *rdev, int crtc)
 {
 	/* disable the pflip int */
 	radeon_irq_kms_pflip_irq_put(rdev, crtc);
 }
 
+/**
+ * r100_page_flip - pageflip callback.
+ *
+ * @rdev: radeon_device pointer
+ * @crtc_id: crtc to cleanup pageflip on
+ * @crtc_base: new address of the crtc (GPU MC address)
+ *
+ * Does the actual pageflip (r1xx-r4xx).
+ * During vblank we take the crtc lock and wait for the update_pending
+ * bit to go high, when it does, we release the lock, and allow the
+ * double buffered update to take place.
+ * Returns the current update pending status.
+ */
 u32 r100_page_flip(struct radeon_device *rdev, int crtc_id, u64 crtc_base)
 {
 	struct radeon_crtc *radeon_crtc = rdev->mode_info.crtcs[crtc_id];
@@ -141,6 +181,15 @@ u32 r100_page_flip(struct radeon_device *rdev, int crtc_id, u64 crtc_base)
 	return RREG32(RADEON_CRTC_OFFSET + radeon_crtc->crtc_offset) & RADEON_CRTC_OFFSET__GUI_TRIG_OFFSET;
 }
 
+/**
+ * r100_pm_get_dynpm_state - look up dynpm power state callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Look up the optimal power state based on the
+ * current state of the GPU (r1xx-r5xx).
+ * Used for dynpm only.
+ */
 void r100_pm_get_dynpm_state(struct radeon_device *rdev)
 {
 	int i;
@@ -223,6 +272,15 @@ void r100_pm_get_dynpm_state(struct radeon_device *rdev)
 		  pcie_lanes);
 }
 
+/**
+ * r100_pm_init_profile - Initialize power profiles callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Initialize the power states used in profile mode
+ * (r1xx-r3xx).
+ * Used for profile mode only.
+ */
 void r100_pm_init_profile(struct radeon_device *rdev)
 {
 	/* default */
@@ -262,6 +320,14 @@ void r100_pm_init_profile(struct radeon_device *rdev)
 	rdev->pm.profiles[PM_PROFILE_HIGH_MH_IDX].dpms_on_cm_idx = 0;
 }
 
+/**
+ * r100_pm_misc - set additional pm hw parameters callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Set non-clock parameters associated with a power state
+ * (voltage, pcie lanes, etc.) (r1xx-r4xx).
+ */
 void r100_pm_misc(struct radeon_device *rdev)
 {
 	int requested_index = rdev->pm.requested_power_state_index;
@@ -353,6 +419,13 @@ void r100_pm_misc(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * r100_pm_prepare - pre-power state change callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Prepare for a power state change (r1xx-r4xx).
+ */
 void r100_pm_prepare(struct radeon_device *rdev)
 {
 	struct drm_device *ddev = rdev->ddev;
@@ -377,6 +450,13 @@ void r100_pm_prepare(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * r100_pm_finish - post-power state change callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Clean up after a power state change (r1xx-r4xx).
+ */
 void r100_pm_finish(struct radeon_device *rdev)
 {
 	struct drm_device *ddev = rdev->ddev;
@@ -401,6 +481,14 @@ void r100_pm_finish(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * r100_gui_idle - gui idle callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Check of the GUI (2D/3D engines) are idle (r1xx-r5xx).
+ * Returns true if idle, false if not.
+ */
 bool r100_gui_idle(struct radeon_device *rdev)
 {
 	if (RREG32(RADEON_RBBM_STATUS) & RADEON_RBBM_ACTIVE)
@@ -410,6 +498,15 @@ bool r100_gui_idle(struct radeon_device *rdev)
 }
 
 /* hpd for digital panel detect/disconnect */
+/**
+ * r100_hpd_sense - hpd sense callback.
+ *
+ * @rdev: radeon_device pointer
+ * @hpd: hpd (hotplug detect) pin
+ *
+ * Checks if a digital monitor is connected (r1xx-r4xx).
+ * Returns true if connected, false if not connected.
+ */
 bool r100_hpd_sense(struct radeon_device *rdev, enum radeon_hpd_id hpd)
 {
 	bool connected = false;
@@ -429,6 +526,14 @@ bool r100_hpd_sense(struct radeon_device *rdev, enum radeon_hpd_id hpd)
 	return connected;
 }
 
+/**
+ * r100_hpd_set_polarity - hpd set polarity callback.
+ *
+ * @rdev: radeon_device pointer
+ * @hpd: hpd (hotplug detect) pin
+ *
+ * Set the polarity of the hpd pin (r1xx-r4xx).
+ */
 void r100_hpd_set_polarity(struct radeon_device *rdev,
 			   enum radeon_hpd_id hpd)
 {
@@ -457,6 +562,14 @@ void r100_hpd_set_polarity(struct radeon_device *rdev,
 	}
 }
 
+/**
+ * r100_hpd_init - hpd setup callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Setup the hpd pins used by the card (r1xx-r4xx).
+ * Set the polarity, and enable the hpd interrupts.
+ */
 void r100_hpd_init(struct radeon_device *rdev)
 {
 	struct drm_device *dev = rdev->ddev;
@@ -471,6 +584,14 @@ void r100_hpd_init(struct radeon_device *rdev)
 	radeon_irq_kms_enable_hpd(rdev, enable);
 }
 
+/**
+ * r100_hpd_fini - hpd tear down callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Tear down the hpd pins used by the card (r1xx-r4xx).
+ * Disable the hpd interrupts.
+ */
 void r100_hpd_fini(struct radeon_device *rdev)
 {
 	struct drm_device *dev = rdev->ddev;
-- 
1.7.7.5

[PATCH 10/10] drm/radeon: start to document evergreen.c

[alexdeucher]

From: Alex Deucher <alexander.deucher@amd.com>

Still a lot to do.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/evergreen.c |  120 ++++++++++++++++++++++++++++++++++++
 1 files changed, 120 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index f716e08..0fc68a7 100644
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -99,6 +99,14 @@ void evergreen_fix_pci_max_read_req_size(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * dce4_wait_for_vblank - vblank wait asic callback.
+ *
+ * @rdev: radeon_device pointer
+ * @crtc: crtc to wait for vblank on
+ *
+ * Wait for vblank on the requested crtc (evergreen+).
+ */
 void dce4_wait_for_vblank(struct radeon_device *rdev, int crtc)
 {
 	struct radeon_crtc *radeon_crtc = rdev->mode_info.crtcs[crtc];
@@ -118,18 +126,49 @@ void dce4_wait_for_vblank(struct radeon_device *rdev, int crtc)
 	}
 }
 
+/**
+ * radeon_irq_kms_pflip_irq_get - pre-pageflip callback.
+ *
+ * @rdev: radeon_device pointer
+ * @crtc: crtc to prepare for pageflip on
+ *
+ * Pre-pageflip callback (evergreen+).
+ * Enables the pageflip irq (vblank irq).
+ */
 void evergreen_pre_page_flip(struct radeon_device *rdev, int crtc)
 {
 	/* enable the pflip int */
 	radeon_irq_kms_pflip_irq_get(rdev, crtc);
 }
 
+/**
+ * evergreen_post_page_flip - pos-pageflip callback.
+ *
+ * @rdev: radeon_device pointer
+ * @crtc: crtc to cleanup pageflip on
+ *
+ * Post-pageflip callback (evergreen+).
+ * Disables the pageflip irq (vblank irq).
+ */
 void evergreen_post_page_flip(struct radeon_device *rdev, int crtc)
 {
 	/* disable the pflip int */
 	radeon_irq_kms_pflip_irq_put(rdev, crtc);
 }
 
+/**
+ * evergreen_page_flip - pageflip callback.
+ *
+ * @rdev: radeon_device pointer
+ * @crtc_id: crtc to cleanup pageflip on
+ * @crtc_base: new address of the crtc (GPU MC address)
+ *
+ * Does the actual pageflip (evergreen+).
+ * During vblank we take the crtc lock and wait for the update_pending
+ * bit to go high, when it does, we release the lock, and allow the
+ * double buffered update to take place.
+ * Returns the current update pending status.
+ */
 u32 evergreen_page_flip(struct radeon_device *rdev, int crtc_id, u64 crtc_base)
 {
 	struct radeon_crtc *radeon_crtc = rdev->mode_info.crtcs[crtc_id];
@@ -214,6 +253,15 @@ int sumo_get_temp(struct radeon_device *rdev)
 	return actual_temp * 1000;
 }
 
+/**
+ * sumo_pm_init_profile - Initialize power profiles callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Initialize the power states used in profile mode
+ * (sumo, trinity, SI).
+ * Used for profile mode only.
+ */
 void sumo_pm_init_profile(struct radeon_device *rdev)
 {
 	int idx;
@@ -265,6 +313,14 @@ void sumo_pm_init_profile(struct radeon_device *rdev)
 		rdev->pm.power_state[idx].num_clock_modes - 1;
 }
 
+/**
+ * evergreen_pm_misc - set additional pm hw parameters callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Set non-clock parameters associated with a power state
+ * (voltage, etc.) (evergreen+).
+ */
 void evergreen_pm_misc(struct radeon_device *rdev)
 {
 	int req_ps_idx = rdev->pm.requested_power_state_index;
@@ -292,6 +348,13 @@ void evergreen_pm_misc(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * evergreen_pm_prepare - pre-power state change callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Prepare for a power state change (evergreen+).
+ */
 void evergreen_pm_prepare(struct radeon_device *rdev)
 {
 	struct drm_device *ddev = rdev->ddev;
@@ -310,6 +373,13 @@ void evergreen_pm_prepare(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * evergreen_pm_finish - post-power state change callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Clean up after a power state change (evergreen+).
+ */
 void evergreen_pm_finish(struct radeon_device *rdev)
 {
 	struct drm_device *ddev = rdev->ddev;
@@ -328,6 +398,15 @@ void evergreen_pm_finish(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * evergreen_hpd_sense - hpd sense callback.
+ *
+ * @rdev: radeon_device pointer
+ * @hpd: hpd (hotplug detect) pin
+ *
+ * Checks if a digital monitor is connected (evergreen+).
+ * Returns true if connected, false if not connected.
+ */
 bool evergreen_hpd_sense(struct radeon_device *rdev, enum radeon_hpd_id hpd)
 {
 	bool connected = false;
@@ -364,6 +443,14 @@ bool evergreen_hpd_sense(struct radeon_device *rdev, enum radeon_hpd_id hpd)
 	return connected;
 }
 
+/**
+ * evergreen_hpd_set_polarity - hpd set polarity callback.
+ *
+ * @rdev: radeon_device pointer
+ * @hpd: hpd (hotplug detect) pin
+ *
+ * Set the polarity of the hpd pin (evergreen+).
+ */
 void evergreen_hpd_set_polarity(struct radeon_device *rdev,
 				enum radeon_hpd_id hpd)
 {
@@ -424,6 +511,14 @@ void evergreen_hpd_set_polarity(struct radeon_device *rdev,
 	}
 }
 
+/**
+ * evergreen_hpd_init - hpd setup callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Setup the hpd pins used by the card (evergreen+).
+ * Enable the pin, set the polarity, and enable the hpd interrupts.
+ */
 void evergreen_hpd_init(struct radeon_device *rdev)
 {
 	struct drm_device *dev = rdev->ddev;
@@ -462,6 +557,14 @@ void evergreen_hpd_init(struct radeon_device *rdev)
 	radeon_irq_kms_enable_hpd(rdev, enabled);
 }
 
+/**
+ * evergreen_hpd_fini - hpd tear down callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Tear down the hpd pins used by the card (evergreen+).
+ * Disable the hpd interrupts.
+ */
 void evergreen_hpd_fini(struct radeon_device *rdev)
 {
 	struct drm_device *dev = rdev->ddev;
@@ -925,6 +1028,14 @@ static void evergreen_program_watermarks(struct radeon_device *rdev,
 
 }
 
+/**
+ * evergreen_bandwidth_update - update display watermarks callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Update the display watermarks based on the requested mode(s)
+ * (evergreen+).
+ */
 void evergreen_bandwidth_update(struct radeon_device *rdev)
 {
 	struct drm_display_mode *mode0 = NULL;
@@ -948,6 +1059,15 @@ void evergreen_bandwidth_update(struct radeon_device *rdev)
 	}
 }
 
+/**
+ * evergreen_mc_wait_for_idle - wait for MC idle callback.
+ *
+ * @rdev: radeon_device pointer
+ *
+ * Wait for the MC (memory controller) to be idle.
+ * (evergreen+).
+ * Returns 0 if the MC is idle, -1 if not.
+ */
 int evergreen_mc_wait_for_idle(struct radeon_device *rdev)
 {
 	unsigned i;
-- 
1.7.7.5

Re: [PATCH 01/10] drm/radeon: document radeon_device.c (v2)

[Christian König]

On 29.06.2012 18:50, alexdeucher@gmail.com wrote:
> From: Alex Deucher <alexander.deucher@amd.com>
>
> Adds documentation to most of the functions in
> radeon_device.c
>
> v2: split out general descriptions as per Christian's
> comments.
>
> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
For the whole series:

Reviewed-by: Christian König <christian.koenig@amd.com>


> ---
>   drivers/gpu/drm/radeon/radeon_device.c |  313 +++++++++++++++++++++++++++++++-
>   1 files changed, 310 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
> index f654ba8..926d7e8 100644
> --- a/drivers/gpu/drm/radeon/radeon_device.c
> +++ b/drivers/gpu/drm/radeon/radeon_device.c
> @@ -96,8 +96,12 @@ static const char radeon_family_name[][16] = {
>   	"LAST",
>   };
>   
> -/*
> - * Clear GPU surface registers.
> +/**
> + * radeon_surface_init - Clear GPU surface registers.
> + *
> + * @rdev: radeon_device pointer
> + *
> + * Clear GPU surface registers (r1xx-r5xx).
>    */
>   void radeon_surface_init(struct radeon_device *rdev)
>   {
> @@ -119,6 +123,13 @@ void radeon_surface_init(struct radeon_device *rdev)
>   /*
>    * GPU scratch registers helpers function.
>    */
> +/**
> + * radeon_scratch_init - Init scratch register driver information.
> + *
> + * @rdev: radeon_device pointer
> + *
> + * Init CP scratch register driver information (r1xx-r5xx)
> + */
>   void radeon_scratch_init(struct radeon_device *rdev)
>   {
>   	int i;
> @@ -136,6 +147,15 @@ void radeon_scratch_init(struct radeon_device *rdev)
>   	}
>   }
>   
> +/**
> + * radeon_scratch_get - Allocate a scratch register
> + *
> + * @rdev: radeon_device pointer
> + * @reg: scratch register mmio offset
> + *
> + * Allocate a CP scratch register for use by the driver (all asics).
> + * Returns 0 on success or -EINVAL on failure.
> + */
>   int radeon_scratch_get(struct radeon_device *rdev, uint32_t *reg)
>   {
>   	int i;
> @@ -150,6 +170,14 @@ int radeon_scratch_get(struct radeon_device *rdev, uint32_t *reg)
>   	return -EINVAL;
>   }
>   
> +/**
> + * radeon_scratch_free - Free a scratch register
> + *
> + * @rdev: radeon_device pointer
> + * @reg: scratch register mmio offset
> + *
> + * Free a CP scratch register allocated for use by the driver (all asics)
> + */
>   void radeon_scratch_free(struct radeon_device *rdev, uint32_t reg)
>   {
>   	int i;
> @@ -162,6 +190,20 @@ void radeon_scratch_free(struct radeon_device *rdev, uint32_t reg)
>   	}
>   }
>   
> +/*
> + * radeon_wb_*()
> + * Writeback is the the method by which the the GPU updates special pages
> + * in memory with the status of certain GPU events (fences, ring pointers,
> + * etc.).
> + */
> +
> +/**
> + * radeon_wb_disable - Disable Writeback
> + *
> + * @rdev: radeon_device pointer
> + *
> + * Disables Writeback (all asics).  Used for suspend.
> + */
>   void radeon_wb_disable(struct radeon_device *rdev)
>   {
>   	int r;
> @@ -177,6 +219,14 @@ void radeon_wb_disable(struct radeon_device *rdev)
>   	rdev->wb.enabled = false;
>   }
>   
> +/**
> + * radeon_wb_fini - Disable Writeback and free memory
> + *
> + * @rdev: radeon_device pointer
> + *
> + * Disables Writeback and frees the Writeback memory (all asics).
> + * Used at driver shutdown.
> + */
>   void radeon_wb_fini(struct radeon_device *rdev)
>   {
>   	radeon_wb_disable(rdev);
> @@ -187,6 +237,15 @@ void radeon_wb_fini(struct radeon_device *rdev)
>   	}
>   }
>   
> +/**
> + * radeon_wb_init- Init Writeback driver info and allocate memory
> + *
> + * @rdev: radeon_device pointer
> + *
> + * Disables Writeback and frees the Writeback memory (all asics).
> + * Used at driver startup.
> + * Returns 0 on success or an -error on failure.
> + */
>   int radeon_wb_init(struct radeon_device *rdev)
>   {
>   	int r;
> @@ -355,6 +414,15 @@ void radeon_gtt_location(struct radeon_device *rdev, struct radeon_mc *mc)
>   /*
>    * GPU helpers function.
>    */
> +/**
> + * radeon_card_posted - check if the hw has already been initialized
> + *
> + * @rdev: radeon_device pointer
> + *
> + * Check if the asic has been initialized (all asics).
> + * Used at driver startup.
> + * Returns true if initialized or false if not.
> + */
>   bool radeon_card_posted(struct radeon_device *rdev)
>   {
>   	uint32_t reg;
> @@ -404,6 +472,14 @@ bool radeon_card_posted(struct radeon_device *rdev)
>   
>   }
>   
> +/**
> + * radeon_update_bandwidth_info - update display bandwidth params
> + *
> + * @rdev: radeon_device pointer
> + *
> + * Used when sclk/mclk are switched or display modes are set.
> + * params are used to calculate display watermarks (all asics)
> + */
>   void radeon_update_bandwidth_info(struct radeon_device *rdev)
>   {
>   	fixed20_12 a;
> @@ -424,6 +500,15 @@ void radeon_update_bandwidth_info(struct radeon_device *rdev)
>   	}
>   }
>   
> +/**
> + * radeon_boot_test_post_card - check and possibly initialize the hw
> + *
> + * @rdev: radeon_device pointer
> + *
> + * Check if the asic is initialized and if not, attempt to initialize
> + * it (all asics).
> + * Returns true if initialized or false if not.
> + */
>   bool radeon_boot_test_post_card(struct radeon_device *rdev)
>   {
>   	if (radeon_card_posted(rdev))
> @@ -442,6 +527,16 @@ bool radeon_boot_test_post_card(struct radeon_device *rdev)
>   	}
>   }
>   
> +/**
> + * radeon_dummy_page_init - init dummy page used by the driver
> + *
> + * @rdev: radeon_device pointer
> + *
> + * Allocate the dummy page used by the driver (all asics).
> + * This dummy page is used by the driver as a filler for gart entries
> + * when pages are taken out of the GART
> + * Returns 0 on sucess, -ENOMEM on failure.
> + */
>   int radeon_dummy_page_init(struct radeon_device *rdev)
>   {
>   	if (rdev->dummy_page.page)
> @@ -460,6 +555,13 @@ int radeon_dummy_page_init(struct radeon_device *rdev)
>   	return 0;
>   }
>   
> +/**
> + * radeon_dummy_page_fini - free dummy page used by the driver
> + *
> + * @rdev: radeon_device pointer
> + *
> + * Frees the dummy page used by the driver (all asics).
> + */
>   void radeon_dummy_page_fini(struct radeon_device *rdev)
>   {
>   	if (rdev->dummy_page.page == NULL)
> @@ -472,6 +574,23 @@ void radeon_dummy_page_fini(struct radeon_device *rdev)
>   
>   
>   /* ATOM accessor methods */
> +/*
> + * ATOM is an interpreted byte code stored in tables in the vbios.  The
> + * driver registers callbacks to access registers and the interpreter
> + * in the driver parses the tables and executes then to program specific
> + * actions (set display modes, asic init, etc.).  See radeon_atombios.c,
> + * atombios.h, and atom.c
> + */
> +
> +/**
> + * cail_pll_read - read PLL register
> + *
> + * @info: atom card_info pointer
> + * @reg: PLL register offset
> + *
> + * Provides a PLL register accessor for the atom interpreter (r4xx+).
> + * Returns the value of the PLL register.
> + */
>   static uint32_t cail_pll_read(struct card_info *info, uint32_t reg)
>   {
>   	struct radeon_device *rdev = info->dev->dev_private;
> @@ -481,6 +600,15 @@ static uint32_t cail_pll_read(struct card_info *info, uint32_t reg)
>   	return r;
>   }
>   
> +/**
> + * cail_pll_write - write PLL register
> + *
> + * @info: atom card_info pointer
> + * @reg: PLL register offset
> + * @val: value to write to the pll register
> + *
> + * Provides a PLL register accessor for the atom interpreter (r4xx+).
> + */
>   static void cail_pll_write(struct card_info *info, uint32_t reg, uint32_t val)
>   {
>   	struct radeon_device *rdev = info->dev->dev_private;
> @@ -488,6 +616,15 @@ static void cail_pll_write(struct card_info *info, uint32_t reg, uint32_t val)
>   	rdev->pll_wreg(rdev, reg, val);
>   }
>   
> +/**
> + * cail_mc_read - read MC (Memory Controller) register
> + *
> + * @info: atom card_info pointer
> + * @reg: MC register offset
> + *
> + * Provides an MC register accessor for the atom interpreter (r4xx+).
> + * Returns the value of the MC register.
> + */
>   static uint32_t cail_mc_read(struct card_info *info, uint32_t reg)
>   {
>   	struct radeon_device *rdev = info->dev->dev_private;
> @@ -497,6 +634,15 @@ static uint32_t cail_mc_read(struct card_info *info, uint32_t reg)
>   	return r;
>   }
>   
> +/**
> + * cail_mc_write - write MC (Memory Controller) register
> + *
> + * @info: atom card_info pointer
> + * @reg: MC register offset
> + * @val: value to write to the pll register
> + *
> + * Provides a MC register accessor for the atom interpreter (r4xx+).
> + */
>   static void cail_mc_write(struct card_info *info, uint32_t reg, uint32_t val)
>   {
>   	struct radeon_device *rdev = info->dev->dev_private;
> @@ -504,6 +650,15 @@ static void cail_mc_write(struct card_info *info, uint32_t reg, uint32_t val)
>   	rdev->mc_wreg(rdev, reg, val);
>   }
>   
> +/**
> + * cail_reg_write - write MMIO register
> + *
> + * @info: atom card_info pointer
> + * @reg: MMIO register offset
> + * @val: value to write to the pll register
> + *
> + * Provides a MMIO register accessor for the atom interpreter (r4xx+).
> + */
>   static void cail_reg_write(struct card_info *info, uint32_t reg, uint32_t val)
>   {
>   	struct radeon_device *rdev = info->dev->dev_private;
> @@ -511,6 +666,15 @@ static void cail_reg_write(struct card_info *info, uint32_t reg, uint32_t val)
>   	WREG32(reg*4, val);
>   }
>   
> +/**
> + * cail_reg_read - read MMIO register
> + *
> + * @info: atom card_info pointer
> + * @reg: MMIO register offset
> + *
> + * Provides an MMIO register accessor for the atom interpreter (r4xx+).
> + * Returns the value of the MMIO register.
> + */
>   static uint32_t cail_reg_read(struct card_info *info, uint32_t reg)
>   {
>   	struct radeon_device *rdev = info->dev->dev_private;
> @@ -520,6 +684,15 @@ static uint32_t cail_reg_read(struct card_info *info, uint32_t reg)
>   	return r;
>   }
>   
> +/**
> + * cail_ioreg_write - write IO register
> + *
> + * @info: atom card_info pointer
> + * @reg: IO register offset
> + * @val: value to write to the pll register
> + *
> + * Provides a IO register accessor for the atom interpreter (r4xx+).
> + */
>   static void cail_ioreg_write(struct card_info *info, uint32_t reg, uint32_t val)
>   {
>   	struct radeon_device *rdev = info->dev->dev_private;
> @@ -527,6 +700,15 @@ static void cail_ioreg_write(struct card_info *info, uint32_t reg, uint32_t val)
>   	WREG32_IO(reg*4, val);
>   }
>   
> +/**
> + * cail_ioreg_read - read IO register
> + *
> + * @info: atom card_info pointer
> + * @reg: IO register offset
> + *
> + * Provides an IO register accessor for the atom interpreter (r4xx+).
> + * Returns the value of the IO register.
> + */
>   static uint32_t cail_ioreg_read(struct card_info *info, uint32_t reg)
>   {
>   	struct radeon_device *rdev = info->dev->dev_private;
> @@ -536,6 +718,16 @@ static uint32_t cail_ioreg_read(struct card_info *info, uint32_t reg)
>   	return r;
>   }
>   
> +/**
> + * radeon_atombios_init - init the driver info and callbacks for atombios
> + *
> + * @rdev: radeon_device pointer
> + *
> + * Initializes the driver info and register access callbacks for the
> + * ATOM interpreter (r4xx+).
> + * Returns 0 on sucess, -ENOMEM on failure.
> + * Called at driver startup.
> + */
>   int radeon_atombios_init(struct radeon_device *rdev)
>   {
>   	struct card_info *atom_card_info =
> @@ -569,6 +761,15 @@ int radeon_atombios_init(struct radeon_device *rdev)
>   	return 0;
>   }
>   
> +/**
> + * radeon_atombios_fini - free the driver info and callbacks for atombios
> + *
> + * @rdev: radeon_device pointer
> + *
> + * Frees the driver info and register access callbacks for the ATOM
> + * interpreter (r4xx+).
> + * Called at driver shutdown.
> + */
>   void radeon_atombios_fini(struct radeon_device *rdev)
>   {
>   	if (rdev->mode_info.atom_context) {
> @@ -578,17 +779,50 @@ void radeon_atombios_fini(struct radeon_device *rdev)
>   	kfree(rdev->mode_info.atom_card_info);
>   }
>   
> +/* COMBIOS */
> +/*
> + * COMBIOS is the bios format prior to ATOM. It provides
> + * command tables similar to ATOM, but doesn't have a unified
> + * parser.  See radeon_combios.c
> + */
> +
> +/**
> + * radeon_combios_init - init the driver info for combios
> + *
> + * @rdev: radeon_device pointer
> + *
> + * Initializes the driver info for combios (r1xx-r3xx).
> + * Returns 0 on sucess.
> + * Called at driver startup.
> + */
>   int radeon_combios_init(struct radeon_device *rdev)
>   {
>   	radeon_combios_initialize_bios_scratch_regs(rdev->ddev);
>   	return 0;
>   }
>   
> +/**
> + * radeon_combios_fini - free the driver info for combios
> + *
> + * @rdev: radeon_device pointer
> + *
> + * Frees the driver info for combios (r1xx-r3xx).
> + * Called at driver shutdown.
> + */
>   void radeon_combios_fini(struct radeon_device *rdev)
>   {
>   }
>   
> -/* if we get transitioned to only one device, tak VGA back */
> +/* if we get transitioned to only one device, take VGA back */
> +/**
> + * radeon_vga_set_decode - enable/disable vga decode
> + *
> + * @cookie: radeon_device pointer
> + * @state: enable/disable vga decode
> + *
> + * Enable/disable vga decode (all asics).
> + * Returns VGA resource flags.
> + */
>   static unsigned int radeon_vga_set_decode(void *cookie, bool state)
>   {
>   	struct radeon_device *rdev = cookie;
> @@ -600,6 +834,14 @@ static unsigned int radeon_vga_set_decode(void *cookie, bool state)
>   		return VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM;
>   }
>   
> +/**
> + * radeon_check_arguments - validate module params
> + *
> + * @rdev: radeon_device pointer
> + *
> + * Validates certain module parameters and updates
> + * the associated values used by the driver (all asics).
> + */
>   void radeon_check_arguments(struct radeon_device *rdev)
>   {
>   	/* vramlimit must be a power of two */
> @@ -666,6 +908,15 @@ void radeon_check_arguments(struct radeon_device *rdev)
>   	}
>   }
>   
> +/**
> + * radeon_switcheroo_set_state - set switcheroo state
> + *
> + * @pdev: pci dev pointer
> + * @state: vga switcheroo state
> + *
> + * Callback for the switcheroo driver.  Suspends or resumes the
> + * the asics before or after it is powered up using ACPI methods.
> + */
>   static void radeon_switcheroo_set_state(struct pci_dev *pdev, enum vga_switcheroo_state state)
>   {
>   	struct drm_device *dev = pci_get_drvdata(pdev);
> @@ -686,6 +937,15 @@ static void radeon_switcheroo_set_state(struct pci_dev *pdev, enum vga_switchero
>   	}
>   }
>   
> +/**
> + * radeon_switcheroo_can_switch - see if switcheroo state can change
> + *
> + * @pdev: pci dev pointer
> + *
> + * Callback for the switcheroo driver.  Check of the switcheroo
> + * state can be changed.
> + * Returns true if the state can be changed, false if not.
> + */
>   static bool radeon_switcheroo_can_switch(struct pci_dev *pdev)
>   {
>   	struct drm_device *dev = pci_get_drvdata(pdev);
> @@ -703,6 +963,18 @@ static const struct vga_switcheroo_client_ops radeon_switcheroo_ops = {
>   	.can_switch = radeon_switcheroo_can_switch,
>   };
>   
> +/**
> + * radeon_device_init - initialize the driver
> + *
> + * @rdev: radeon_device pointer
> + * @pdev: drm dev pointer
> + * @pdev: pci dev pointer
> + * @flags: driver flags
> + *
> + * Initializes the driver info and hw (all asics).
> + * Returns 0 for success or an error on failure.
> + * Called at driver startup.
> + */
>   int radeon_device_init(struct radeon_device *rdev,
>   		       struct drm_device *ddev,
>   		       struct pci_dev *pdev,
> @@ -846,6 +1118,14 @@ int radeon_device_init(struct radeon_device *rdev,
>   
>   static void radeon_debugfs_remove_files(struct radeon_device *rdev);
>   
> +/**
> + * radeon_device_fini - tear down the driver
> + *
> + * @rdev: radeon_device pointer
> + *
> + * Tear down the driver info (all asics).
> + * Called at driver shutdown.
> + */
>   void radeon_device_fini(struct radeon_device *rdev)
>   {
>   	DRM_INFO("radeon: finishing device.\n");
> @@ -867,6 +1147,16 @@ void radeon_device_fini(struct radeon_device *rdev)
>   /*
>    * Suspend & resume.
>    */
> +/**
> + * radeon_suspend_kms - initiate device suspend
> + *
> + * @pdev: drm dev pointer
> + * @state: suspend state
> + *
> + * Puts the hw in the suspend state (all asics).
> + * Returns 0 for success or an error on failure.
> + * Called at driver suspend.
> + */
>   int radeon_suspend_kms(struct drm_device *dev, pm_message_t state)
>   {
>   	struct radeon_device *rdev;
> @@ -941,6 +1231,15 @@ int radeon_suspend_kms(struct drm_device *dev, pm_message_t state)
>   	return 0;
>   }
>   
> +/**
> + * radeon_resume_kms - initiate device resume
> + *
> + * @pdev: drm dev pointer
> + *
> + * Bring the hw back to operating state (all asics).
> + * Returns 0 for success or an error on failure.
> + * Called at driver resume.
> + */
>   int radeon_resume_kms(struct drm_device *dev)
>   {
>   	struct drm_connector *connector;
> @@ -983,6 +1282,14 @@ int radeon_resume_kms(struct drm_device *dev)
>   	return 0;
>   }
>   
> +/**
> + * radeon_gpu_reset - reset the asic
> + *
> + * @rdev: radeon device pointer
> + *
> + * Attempt the reset the GPU if it has hung (all asics).
> + * Returns 0 for success or an error on failure.
> + */
>   int radeon_gpu_reset(struct radeon_device *rdev)
>   {
>   	int r;