Resizeable PCI BAR support v5

Resizeable PCI BAR support v5

[Christian König]

Hi everyone,

this is the fifth incarnation of this set of patches. It enables device
drivers to resize and most likely also relocate the PCI BAR of devices
they manage to allow the CPU to access all of the device local memory at once.

This is very useful for GFX device drivers where the default PCI BAR is only
about 256MB in size for compatibility reasons, but the device easily have
multiple gigabyte of local memory.

Noteable changed compared to v4:
1. Patch #1 is new and a minor cleanup to the PCI code.
2. Some more helpers added to patch #2
3. We now print a note to syslog before releasing resources.
4. Add defines for registers and bits used to add new root hub window.

I've addressed mostly every review comment I've got so far and it looks like we
are getting closer to landing this. Any more suggestions/hints how we could
improve the patchset would be very welcome.

Thanks in advance,
Christian.

[PATCH 1/5] PCI: add a define for the PCI resource type mask

[Christian König]

From: Christian König <christian.koenig@amd.com>

We use this mask multiple times in the bus setup.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/pci/pci.h       |  3 +++
 drivers/pci/setup-bus.c | 14 +++++---------
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 4518562..3868828 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -6,6 +6,9 @@
 
 #define PCI_FIND_CAP_TTL	48
 
+#define PCI_RES_TYPE_MASK (IORESOURCE_IO | IORESOURCE_MEM | \
+			   IORESOURCE_PREFETCH | IORESOURCE_MEM_64)
+
 extern const unsigned char pcie_link_speed[];
 
 bool pcie_cap_has_lnkctl(const struct pci_dev *dev);
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index f30ca75..bb1001e 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1532,8 +1532,6 @@ static void pci_bridge_release_resources(struct pci_bus *bus,
 {
 	struct pci_dev *dev = bus->self;
 	struct resource *r;
-	unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
-				  IORESOURCE_PREFETCH | IORESOURCE_MEM_64;
 	unsigned old_flags = 0;
 	struct resource *b_res;
 	int idx = 1;
@@ -1576,7 +1574,7 @@ static void pci_bridge_release_resources(struct pci_bus *bus,
 	 */
 	release_child_resources(r);
 	if (!release_resource(r)) {
-		type = old_flags = r->flags & type_mask;
+		type = old_flags = r->flags & PCI_RES_TYPE_MASK;
 		dev_printk(KERN_DEBUG, &dev->dev, "resource %d %pR released\n",
 					PCI_BRIDGE_RESOURCES + idx, r);
 		/* keep the old size */
@@ -1767,8 +1765,6 @@ void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus)
 	enum release_type rel_type = leaf_only;
 	LIST_HEAD(fail_head);
 	struct pci_dev_resource *fail_res;
-	unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
-				  IORESOURCE_PREFETCH | IORESOURCE_MEM_64;
 	int pci_try_num = 1;
 	enum enable_type enable_local;
 
@@ -1827,7 +1823,8 @@ void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus)
 	 */
 	list_for_each_entry(fail_res, &fail_head, list)
 		pci_bus_release_bridge_resources(fail_res->dev->bus,
-						 fail_res->flags & type_mask,
+						 fail_res->flags &
+						 PCI_RES_TYPE_MASK,
 						 rel_type);
 
 	/* restore size and flags */
@@ -1871,8 +1868,6 @@ void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
 	LIST_HEAD(fail_head);
 	struct pci_dev_resource *fail_res;
 	int retval;
-	unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
-				  IORESOURCE_PREFETCH | IORESOURCE_MEM_64;
 
 again:
 	__pci_bus_size_bridges(parent, &add_list);
@@ -1898,7 +1893,8 @@ void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
 	 */
 	list_for_each_entry(fail_res, &fail_head, list)
 		pci_bus_release_bridge_resources(fail_res->dev->bus,
-						 fail_res->flags & type_mask,
+						 fail_res->flags &
+						 PCI_RES_TYPE_MASK,
 						 whole_subtree);
 
 	/* restore size and flags */
-- 
2.7.4

Re: [PATCH 1/5] PCI: add a define for the PCI resource type mask

[Andy Shevchenko]

On Thu, May 4, 2017 at 12:31 PM, Christian K=C3=B6nig
<deathsimple@vodafone.de> wrote:
> From: Christian K=C3=B6nig <christian.koenig@amd.com>
>
> We use this mask multiple times in the bus setup.

Couple of nitpicks below.
Otherwise, FWIW:

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

> +#define PCI_RES_TYPE_MASK (IORESOURCE_IO | IORESOURCE_MEM | \
> +                          IORESOURCE_PREFETCH | IORESOURCE_MEM_64)

I would go with following indentation:
#define PCI_RES_TYPE_MASK \
(IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH | IORESOURCE_MEM_64)

or (if it doesn't fit well)

#define PCI_RES_TYPE_MASK \
    (IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH | \
     IORESOURCE_MEM_64)

>                 pci_bus_release_bridge_resources(fail_res->dev->bus,
> -                                                fail_res->flags & type_m=
ask,
> +                                                fail_res->flags &
> +                                                PCI_RES_TYPE_MASK,

I would leave it on one line even if it goes as far as ~85ish column.

>                 pci_bus_release_bridge_resources(fail_res->dev->bus,
> -                                                fail_res->flags & type_m=
ask,
> +                                                fail_res->flags &
> +                                                PCI_RES_TYPE_MASK,

Ditto.

--=20
With Best Regards,
Andy Shevchenko

[PATCH 2/5] PCI: add resizeable BAR infrastructure v5

[Christian König]

From: Christian König <christian.koenig@amd.com>

Just the defines and helper functions to read the possible sizes of a BAR and
update it's size.

See https://pcisig.com/sites/default/files/specification_documents/ECN_Resizable-BAR_24Apr2008.pdf
and PCIe r3.1, sec 7.22.

This is useful for hardware with large local storage (mostly GFX) which only
expose 256MB BARs initially to be compatible with 32bit systems.

v2: provide read helper as well
v3: improve function names, use unsigned values, add better comments.
v4: move definition, improve commit message, s/bar/BAR/
v5: split out helper to find ctrl reg pos, style fixes, comment fixes,
    add pci_rbar_size_to_bytes as well

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/pci/pci.c             | 104 ++++++++++++++++++++++++++++++++++++++++++
 drivers/pci/pci.h             |   8 ++++
 include/uapi/linux/pci_regs.h |  11 ++++-
 3 files changed, 121 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index ba34907..0cbf4a6 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2944,6 +2944,110 @@ bool pci_acs_path_enabled(struct pci_dev *start,
 }
 
 /**
+ * pci_rbar_find_pos - find position of resize ctrl reg for BAR
+ * @dev: PCI device
+ * @bar: BAR to find
+ *
+ * Helper to find the postion of the ctrl register for a BAR.
+ * Returns -ENOTSUPP of resizeable BARs are not supported at all.
+ * Returns -ENOENT if not ctrl register for the BAR could be found.
+ */
+static int pci_rbar_find_pos(struct pci_dev *pdev, int bar)
+{
+	unsigned int pos, nbars;
+	unsigned int i;
+	u32 ctrl;
+
+	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
+	if (!pos)
+		return -ENOTSUPP;
+
+	pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
+	nbars = (ctrl & PCI_REBAR_CTRL_NBAR_MASK) >> PCI_REBAR_CTRL_NBAR_SHIFT;
+
+	for (i = 0; i < nbars; ++i, pos += 8) {
+		int bar_idx;
+
+		pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
+		bar_idx = (ctrl & PCI_REBAR_CTRL_BAR_IDX_MASK) >>
+				PCI_REBAR_CTRL_BAR_IDX_SHIFT;
+		if (bar_idx == bar)
+			return pos;
+	}
+
+	return -ENOENT;
+}
+
+/**
+ * pci_rbar_get_possible_sizes - get possible sizes for BAR
+ * @dev: PCI device
+ * @bar: BAR to query
+ *
+ * Get the possible sizes of a resizeable BAR as bitmask defined in the spec
+ * (bit 0=1MB, bit 19=512GB). Returns 0 if BAR isn't resizeable.
+ */
+u32 pci_rbar_get_possible_sizes(struct pci_dev *pdev, int bar)
+{
+	u32 cap;
+	int pos;
+
+	pos = pci_rbar_find_pos(pdev, bar);
+	if (pos < 0)
+		return 0;
+
+	pci_read_config_dword(pdev, pos + PCI_REBAR_CAP, &cap);
+	return (cap & PCI_REBAR_CTRL_SIZES_MASK) >>
+		PCI_REBAR_CTRL_SIZES_SHIFT;
+}
+
+/**
+ * pci_rbar_get_current_size - get the current size of a BAR
+ * @dev: PCI device
+ * @bar: BAR to set size to
+ *
+ * Read the size of a BAR from the resizeable BAR config.
+ * Returns size if found or negative error code.
+ */
+int pci_rbar_get_current_size(struct pci_dev *pdev, int bar)
+{
+	u32 ctrl;
+	int pos;
+
+	pos = pci_rbar_find_pos(pdev, bar);
+	if (pos < 0)
+		return pos;
+
+	pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
+	return (ctrl & PCI_REBAR_CTRL_BAR_SIZE_MASK) >>
+		PCI_REBAR_CTRL_BAR_SIZE_SHIFT;
+}
+
+/**
+ * pci_rbar_set_size - set a new size for a BAR
+ * @dev: PCI device
+ * @bar: BAR to set size to
+ * @size: new size as defined in the spec (0=1MB, 19=512GB)
+ *
+ * Set the new size of a BAR as defined in the spec.
+ * Returns zero if resizing was successful, error code otherwise.
+ */
+int pci_rbar_set_size(struct pci_dev *pdev, int bar, int size)
+{
+	u32 ctrl;
+	int pos;
+
+	pos = pci_rbar_find_pos(pdev, bar);
+	if (pos < 0)
+		return pos;
+
+	pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
+	ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE_MASK;
+	ctrl |= size << PCI_REBAR_CTRL_BAR_SIZE_SHIFT;
+	pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl);
+	return 0;
+}
+
+/**
  * pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge
  * @dev: the PCI device
  * @pin: the INTx pin (1=INTA, 2=INTB, 3=INTC, 4=INTD)
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 3868828..6290e5c 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -359,4 +359,12 @@ static inline int pci_dev_specific_reset(struct pci_dev *dev, int probe)
 }
 #endif
 
+u32 pci_rbar_get_possible_sizes(struct pci_dev *pdev, int bar);
+int pci_rbar_get_current_size(struct pci_dev *pdev, int bar);
+int pci_rbar_set_size(struct pci_dev *pdev, int bar, int size);
+static inline u64 pci_rbar_size_to_bytes(int size)
+{
+	return 1ULL << (size + 20);
+}
+
 #endif /* DRIVERS_PCI_H */
diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
index e5a2e68..a75429e 100644
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h
@@ -932,9 +932,16 @@
 #define PCI_SATA_SIZEOF_LONG	16
 
 /* Resizable BARs */
+#define PCI_REBAR_CAP		4	/* capability register */
+#define  PCI_REBAR_CTRL_SIZES_MASK	(0xFFFFF << 4)	/* mask for sizes */
+#define  PCI_REBAR_CTRL_SIZES_SHIFT	4	/* shift for sizes */
 #define PCI_REBAR_CTRL		8	/* control register */
-#define  PCI_REBAR_CTRL_NBAR_MASK	(7 << 5)	/* mask for # bars */
-#define  PCI_REBAR_CTRL_NBAR_SHIFT	5	/* shift for # bars */
+#define  PCI_REBAR_CTRL_BAR_IDX_MASK	(7 << 0)	/* mask for BAR index */
+#define  PCI_REBAR_CTRL_BAR_IDX_SHIFT	0	/* shift for BAR index */
+#define  PCI_REBAR_CTRL_NBAR_MASK	(7 << 5)	/* mask for # BARs */
+#define  PCI_REBAR_CTRL_NBAR_SHIFT	5	/* shift for # BARs */
+#define  PCI_REBAR_CTRL_BAR_SIZE_MASK	(0x1F << 8)	/* mask for BAR size */
+#define  PCI_REBAR_CTRL_BAR_SIZE_SHIFT	8	/* shift for BAR size */
 
 /* Dynamic Power Allocation */
 #define PCI_DPA_CAP		4	/* capability register */
-- 
2.7.4

Re: [PATCH 2/5] PCI: add resizeable BAR infrastructure v5

[Andy Shevchenko]

On Thu, May 4, 2017 at 12:31 PM, Christian K=C3=B6nig
<deathsimple@vodafone.de> wrote:
> From: Christian K=C3=B6nig <christian.koenig@amd.com>
>
> Just the defines and helper functions to read the possible sizes of a BAR=
 and
> update it's size.
>
> See https://pcisig.com/sites/default/files/specification_documents/ECN_Re=
sizable-BAR_24Apr2008.pdf
> and PCIe r3.1, sec 7.22.
>
> This is useful for hardware with large local storage (mostly GFX) which o=
nly
> expose 256MB BARs initially to be compatible with 32bit systems.
>

Now looks nice!

FWIW:
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

> v2: provide read helper as well
> v3: improve function names, use unsigned values, add better comments.
> v4: move definition, improve commit message, s/bar/BAR/
> v5: split out helper to find ctrl reg pos, style fixes, comment fixes,
>     add pci_rbar_size_to_bytes as well
>
> Signed-off-by: Christian K=C3=B6nig <christian.koenig@amd.com>
> ---
>  drivers/pci/pci.c             | 104 ++++++++++++++++++++++++++++++++++++=
++++++
>  drivers/pci/pci.h             |   8 ++++
>  include/uapi/linux/pci_regs.h |  11 ++++-
>  3 files changed, 121 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index ba34907..0cbf4a6 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -2944,6 +2944,110 @@ bool pci_acs_path_enabled(struct pci_dev *start,
>  }
>
>  /**
> + * pci_rbar_find_pos - find position of resize ctrl reg for BAR
> + * @dev: PCI device
> + * @bar: BAR to find
> + *
> + * Helper to find the postion of the ctrl register for a BAR.
> + * Returns -ENOTSUPP of resizeable BARs are not supported at all.
> + * Returns -ENOENT if not ctrl register for the BAR could be found.
> + */
> +static int pci_rbar_find_pos(struct pci_dev *pdev, int bar)
> +{
> +       unsigned int pos, nbars;
> +       unsigned int i;
> +       u32 ctrl;
> +
> +       pos =3D pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
> +       if (!pos)
> +               return -ENOTSUPP;
> +
> +       pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
> +       nbars =3D (ctrl & PCI_REBAR_CTRL_NBAR_MASK) >> PCI_REBAR_CTRL_NBA=
R_SHIFT;
> +
> +       for (i =3D 0; i < nbars; ++i, pos +=3D 8) {
> +               int bar_idx;
> +
> +               pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
> +               bar_idx =3D (ctrl & PCI_REBAR_CTRL_BAR_IDX_MASK) >>
> +                               PCI_REBAR_CTRL_BAR_IDX_SHIFT;
> +               if (bar_idx =3D=3D bar)
> +                       return pos;
> +       }
> +
> +       return -ENOENT;
> +}
> +
> +/**
> + * pci_rbar_get_possible_sizes - get possible sizes for BAR
> + * @dev: PCI device
> + * @bar: BAR to query
> + *
> + * Get the possible sizes of a resizeable BAR as bitmask defined in the =
spec
> + * (bit 0=3D1MB, bit 19=3D512GB). Returns 0 if BAR isn't resizeable.
> + */
> +u32 pci_rbar_get_possible_sizes(struct pci_dev *pdev, int bar)
> +{
> +       u32 cap;
> +       int pos;
> +
> +       pos =3D pci_rbar_find_pos(pdev, bar);
> +       if (pos < 0)
> +               return 0;
> +
> +       pci_read_config_dword(pdev, pos + PCI_REBAR_CAP, &cap);
> +       return (cap & PCI_REBAR_CTRL_SIZES_MASK) >>
> +               PCI_REBAR_CTRL_SIZES_SHIFT;
> +}
> +
> +/**
> + * pci_rbar_get_current_size - get the current size of a BAR
> + * @dev: PCI device
> + * @bar: BAR to set size to
> + *
> + * Read the size of a BAR from the resizeable BAR config.
> + * Returns size if found or negative error code.
> + */
> +int pci_rbar_get_current_size(struct pci_dev *pdev, int bar)
> +{
> +       u32 ctrl;
> +       int pos;
> +
> +       pos =3D pci_rbar_find_pos(pdev, bar);
> +       if (pos < 0)
> +               return pos;
> +
> +       pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
> +       return (ctrl & PCI_REBAR_CTRL_BAR_SIZE_MASK) >>
> +               PCI_REBAR_CTRL_BAR_SIZE_SHIFT;
> +}
> +
> +/**
> + * pci_rbar_set_size - set a new size for a BAR
> + * @dev: PCI device
> + * @bar: BAR to set size to
> + * @size: new size as defined in the spec (0=3D1MB, 19=3D512GB)
> + *
> + * Set the new size of a BAR as defined in the spec.
> + * Returns zero if resizing was successful, error code otherwise.
> + */
> +int pci_rbar_set_size(struct pci_dev *pdev, int bar, int size)
> +{
> +       u32 ctrl;
> +       int pos;
> +
> +       pos =3D pci_rbar_find_pos(pdev, bar);
> +       if (pos < 0)
> +               return pos;
> +
> +       pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
> +       ctrl &=3D ~PCI_REBAR_CTRL_BAR_SIZE_MASK;
> +       ctrl |=3D size << PCI_REBAR_CTRL_BAR_SIZE_SHIFT;
> +       pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl);
> +       return 0;
> +}
> +
> +/**
>   * pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge
>   * @dev: the PCI device
>   * @pin: the INTx pin (1=3DINTA, 2=3DINTB, 3=3DINTC, 4=3DINTD)
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index 3868828..6290e5c 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -359,4 +359,12 @@ static inline int pci_dev_specific_reset(struct pci_=
dev *dev, int probe)
>  }
>  #endif
>
> +u32 pci_rbar_get_possible_sizes(struct pci_dev *pdev, int bar);
> +int pci_rbar_get_current_size(struct pci_dev *pdev, int bar);
> +int pci_rbar_set_size(struct pci_dev *pdev, int bar, int size);
> +static inline u64 pci_rbar_size_to_bytes(int size)
> +{
> +       return 1ULL << (size + 20);
> +}
> +
>  #endif /* DRIVERS_PCI_H */
> diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.=
h
> index e5a2e68..a75429e 100644
> --- a/include/uapi/linux/pci_regs.h
> +++ b/include/uapi/linux/pci_regs.h
> @@ -932,9 +932,16 @@
>  #define PCI_SATA_SIZEOF_LONG   16
>
>  /* Resizable BARs */
> +#define PCI_REBAR_CAP          4       /* capability register */
> +#define  PCI_REBAR_CTRL_SIZES_MASK     (0xFFFFF << 4)  /* mask for sizes=
 */
> +#define  PCI_REBAR_CTRL_SIZES_SHIFT    4       /* shift for sizes */
>  #define PCI_REBAR_CTRL         8       /* control register */
> -#define  PCI_REBAR_CTRL_NBAR_MASK      (7 << 5)        /* mask for # bar=
s */
> -#define  PCI_REBAR_CTRL_NBAR_SHIFT     5       /* shift for # bars */
> +#define  PCI_REBAR_CTRL_BAR_IDX_MASK   (7 << 0)        /* mask for BAR i=
ndex */
> +#define  PCI_REBAR_CTRL_BAR_IDX_SHIFT  0       /* shift for BAR index */
> +#define  PCI_REBAR_CTRL_NBAR_MASK      (7 << 5)        /* mask for # BAR=
s */
> +#define  PCI_REBAR_CTRL_NBAR_SHIFT     5       /* shift for # BARs */
> +#define  PCI_REBAR_CTRL_BAR_SIZE_MASK  (0x1F << 8)     /* mask for BAR s=
ize */
> +#define  PCI_REBAR_CTRL_BAR_SIZE_SHIFT 8       /* shift for BAR size */
>
>  /* Dynamic Power Allocation */
>  #define PCI_DPA_CAP            4       /* capability register */
> --
> 2.7.4
>



--=20
With Best Regards,
Andy Shevchenko

[PATCH 3/5] PCI: add functionality for resizing resources v4

[Christian König]

From: Christian König <christian.koenig@amd.com>

This allows device drivers to request resizing their BARs.

The function only tries to reprogram the windows of the bridge directly above
the requesting device and only the BAR of the same type (usually mem, 64bit,
prefetchable). This is done to make sure not to disturb other drivers by
changing the BARs of their devices.

If reprogramming the bridge BAR fails the old status is restored and -ENOSPC
returned to the calling device driver.

v2: rebase on changes in rbar support
v3: style cleanups, fail if memory decoding is enabled or resources
    still allocated, resize all unused bridge BARs,
    drop calling pci_reenable_device
v4: print resources before releasing them, style cleanups,
    use pci_rbar_size_to_bytes, use PCI_RES_TYPE_MASK

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/pci/setup-bus.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++++
 drivers/pci/setup-res.c | 59 +++++++++++++++++++++++++++++
 include/linux/pci.h     |  3 ++
 3 files changed, 160 insertions(+)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index bb1001e..2b73e0e 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1919,6 +1919,104 @@ void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
 }
 EXPORT_SYMBOL_GPL(pci_assign_unassigned_bridge_resources);
 
+int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type)
+{
+	struct pci_dev_resource *dev_res;
+	LIST_HEAD(saved);
+	LIST_HEAD(added);
+	LIST_HEAD(failed);
+	unsigned int i;
+	int ret;
+
+	/* Walk to the root BUS, releasing bridge BARs when possible */
+	while (1) {
+		for (i = PCI_BRIDGE_RESOURCES; i < PCI_BRIDGE_RESOURCE_END;
+		     i++) {
+			struct resource *res = &bridge->resource[i];
+
+			if ((res->flags ^ type) & PCI_RES_TYPE_MASK)
+				continue;
+
+			/* Ignore BARs which are still in use */
+			if (res->child)
+				continue;
+
+			ret = add_to_list(&saved, bridge, res, 0, 0);
+			if (ret)
+				goto cleanup;
+
+			dev_info(&bridge->dev, "BAR %d: releasing %pR\n",
+				 i, res);
+
+			if (res->parent)
+				release_resource(res);
+			res->start = 0;
+			res->end = 0;
+			break;
+		}
+		if (i == PCI_BRIDGE_RESOURCE_END)
+			break;
+
+		if (!bridge->bus || !bridge->bus->self)
+			break;
+
+		bridge = bridge->bus->self;
+	}
+
+	if (list_empty(&saved))
+		return -ENOENT;
+
+	__pci_bus_size_bridges(bridge->subordinate, &added);
+	__pci_bridge_assign_resources(bridge, &added, &failed);
+	BUG_ON(!list_empty(&added));
+
+	if (!list_empty(&failed)) {
+		ret = -ENOSPC;
+		goto cleanup;
+	}
+
+	list_for_each_entry(dev_res, &saved, list) {
+		/* Skip the bridge we just assigned resources for. */
+		if (bridge == dev_res->dev)
+			continue;
+
+		bridge = dev_res->dev;
+		pci_setup_bridge(bridge->subordinate);
+	}
+
+	free_list(&saved);
+	return 0;
+
+cleanup:
+	/* restore size and flags */
+	list_for_each_entry(dev_res, &failed, list) {
+		struct resource *res = dev_res->res;
+
+		res->start = dev_res->start;
+		res->end = dev_res->end;
+		res->flags = dev_res->flags;
+	}
+	free_list(&failed);
+
+	/* Revert to the old configuration */
+	list_for_each_entry(dev_res, &saved, list) {
+		struct resource *res = dev_res->res;
+
+		bridge = dev_res->dev;
+		i = res - bridge->resource;
+
+		res->start = dev_res->start;
+		res->end = dev_res->end;
+		res->flags = dev_res->flags;
+
+		pci_claim_resource(bridge, i);
+		pci_setup_bridge(bridge->subordinate);
+	}
+	free_list(&saved);
+
+	return ret;
+}
+
 void pci_assign_unassigned_bus_resources(struct pci_bus *bus)
 {
 	struct pci_dev *dev;
diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 9526e34..65420ac 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -363,6 +363,65 @@ int pci_reassign_resource(struct pci_dev *dev, int resno, resource_size_t addsiz
 	return 0;
 }
 
+void pci_release_resource(struct pci_dev *dev, int resno)
+{
+	struct resource *res = dev->resource + resno;
+
+	dev_info(&dev->dev, "BAR %d: releasing %pR\n", resno, res);
+	release_resource(res);
+	res->end = resource_size(res) - 1;
+	res->start = 0;
+	res->flags |= IORESOURCE_UNSET;
+}
+EXPORT_SYMBOL(pci_release_resource);
+
+int pci_resize_resource(struct pci_dev *dev, int resno, int size)
+{
+	struct resource *res = dev->resource + resno;
+	int old, ret = 0;
+	u32 sizes;
+	u16 cmd;
+
+	pci_read_config_word(dev, PCI_COMMAND, &cmd);
+	if (cmd & PCI_COMMAND_MEMORY)
+		return -EBUSY;
+
+	sizes = pci_rbar_get_possible_sizes(dev, resno);
+	if (!sizes)
+		return -ENOTSUPP;
+
+	if (!(sizes & BIT(size)))
+		return -EINVAL;
+
+	old = pci_rbar_get_current_size(dev, resno);
+	if (old < 0)
+		return old;
+
+	/* Make sure the resource isn't assigned before making it larger. */
+	pci_release_resource(dev, resno);
+
+	ret = pci_rbar_set_size(dev, resno, size);
+	if (ret)
+		goto error_reassign;
+
+	res->end = res->start + pci_rbar_size_to_bytes(size) - 1;
+
+	ret = pci_reassign_bridge_resources(dev->bus->self, res->flags);
+	if (ret)
+		goto error_resize;
+
+	return 0;
+
+error_resize:
+	pci_rbar_set_size(dev, resno, old);
+	res->end = res->start + pci_rbar_size_to_bytes(old) - 1;
+
+error_reassign:
+	pci_assign_unassigned_bus_resources(dev->bus);
+	return ret;
+}
+EXPORT_SYMBOL(pci_resize_resource);
+
 int pci_enable_resources(struct pci_dev *dev, int mask)
 {
 	u16 cmd, old_cmd;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index a38772a..f0a630a 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1055,6 +1055,8 @@ void pci_reset_bridge_secondary_bus(struct pci_dev *dev);
 void pci_update_resource(struct pci_dev *dev, int resno);
 int __must_check pci_assign_resource(struct pci_dev *dev, int i);
 int __must_check pci_reassign_resource(struct pci_dev *dev, int i, resource_size_t add_size, resource_size_t align);
+void pci_release_resource(struct pci_dev *dev, int resno);
+int __must_check pci_resize_resource(struct pci_dev *dev, int i, int size);
 int pci_select_bars(struct pci_dev *dev, unsigned long flags);
 bool pci_device_is_present(struct pci_dev *pdev);
 void pci_ignore_hotplug(struct pci_dev *dev);
@@ -1135,6 +1137,7 @@ void pci_assign_unassigned_resources(void);
 void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge);
 void pci_assign_unassigned_bus_resources(struct pci_bus *bus);
 void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus);
+int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type);
 void pdev_enable_device(struct pci_dev *);
 int pci_enable_resources(struct pci_dev *, int mask);
 void pci_fixup_irqs(u8 (*)(struct pci_dev *, u8 *),
-- 
2.7.4

Re: [PATCH 3/5] PCI: add functionality for resizing resources v4

[Andy Shevchenko]

On Thu, May 4, 2017 at 12:31 PM, Christian K=C3=B6nig
<deathsimple@vodafone.de> wrote:
> From: Christian K=C3=B6nig <christian.koenig@amd.com>
>
> This allows device drivers to request resizing their BARs.
>
> The function only tries to reprogram the windows of the bridge directly a=
bove
> the requesting device and only the BAR of the same type (usually mem, 64b=
it,
> prefetchable). This is done to make sure not to disturb other drivers by
> changing the BARs of their devices.
>
> If reprogramming the bridge BAR fails the old status is restored and -ENO=
SPC
> returned to the calling device driver.

My comments below.

> +int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long =
type)
> +{
> +       struct pci_dev_resource *dev_res;
> +       LIST_HEAD(saved);
> +       LIST_HEAD(added);
> +       LIST_HEAD(failed);
> +       unsigned int i;
> +       int ret;
> +
> +       /* Walk to the root BUS, releasing bridge BARs when possible */
> +       while (1) {
> +               for (i =3D PCI_BRIDGE_RESOURCES; i < PCI_BRIDGE_RESOURCE_=
END;
> +                    i++) {
> +                       struct resource *res =3D &bridge->resource[i];
> +
> +                       if ((res->flags ^ type) & PCI_RES_TYPE_MASK)
> +                               continue;
> +
> +                       /* Ignore BARs which are still in use */
> +                       if (res->child)
> +                               continue;
> +
> +                       ret =3D add_to_list(&saved, bridge, res, 0, 0);
> +                       if (ret)
> +                               goto cleanup;
> +
> +                       dev_info(&bridge->dev, "BAR %d: releasing %pR\n",
> +                                i, res);
> +
> +                       if (res->parent)
> +                               release_resource(res);
> +                       res->start =3D 0;
> +                       res->end =3D 0;
> +                       break;
> +               }
> +               if (i =3D=3D PCI_BRIDGE_RESOURCE_END)
> +                       break;
> +
> +               if (!bridge->bus || !bridge->bus->self)
> +                       break;
> +
> +               bridge =3D bridge->bus->self;
> +       }
> +

Please, consider to refactor as I proposed the other day.

> +}

> +int pci_resize_resource(struct pci_dev *dev, int resno, int size)
> +{
> +       struct resource *res =3D dev->resource + resno;

> +       int old, ret =3D 0;

Redundant assignment.

> +       u32 sizes;
> +       u16 cmd;
> +

> +       ret =3D pci_rbar_set_size(dev, resno, size);
> +       if (ret)
> +               goto error_reassign;
> +

> +       return 0;
> +
> +error_resize:
> +       pci_rbar_set_size(dev, resno, old);
> +       res->end =3D res->start + pci_rbar_size_to_bytes(old) - 1;
> +
> +error_reassign:
> +       pci_assign_unassigned_bus_resources(dev->bus);
> +       return ret;
> +}

--=20
With Best Regards,
Andy Shevchenko

[PATCH 4/5] x86/PCI: Enable a 64bit BAR on AMD Family 15h (Models 30h-3fh) Processors v3

[Christian König]

From: Christian König <christian.koenig@amd.com>

Most BIOS don't enable this because of compatibility reasons.

Manually enable a 64bit BAR of 64GB size so that we have
enough room for PCI devices.

v2: style cleanups, increase size, add resource name, set correct flags,
    print message that windows was added
v3: add defines for all the magic numbers, style cleanups

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 arch/x86/pci/fixup.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)

diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
index 6d52b94..1c36ed6 100644
--- a/arch/x86/pci/fixup.c
+++ b/arch/x86/pci/fixup.c
@@ -571,3 +571,72 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2fc0, pci_invalid_bar);
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6f60, pci_invalid_bar);
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fa0, pci_invalid_bar);
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fc0, pci_invalid_bar);
+
+#define AMD_141b_MMIO_BASE(x)	(0x80 + (x) * 0x8)
+#define AMD_141b_MMIO_BASE_RE_MASK		BIT(0)
+#define AMD_141b_MMIO_BASE_WE_MASK		BIT(1)
+#define AMD_141b_MMIO_BASE_MMIOBASE_MASK	GENMASK(31,8)
+
+#define AMD_141b_MMIO_LIMIT(x)	(0x84 + (x) * 0x8)
+#define AMD_141b_MMIO_LIMIT_MMIOLIMIT_MASK	GENMASK(31,8)
+
+#define AMD_141b_MMIO_HIGH(x)	(0x180 + (x) * 0x4)
+#define AMD_141b_MMIO_HIGH_MMIOBASE_MASK	GENMASK(7,0)
+#define AMD_141b_MMIO_HIGH_MMIOLIMIT_SHIFT	16
+#define AMD_141b_MMIO_HIGH_MMIOLIMIT_MASK	GENMASK(23,16)
+
+static void pci_amd_enable_64bit_bar(struct pci_dev *dev)
+{
+	struct resource *res, *conflict;
+	u32 base, limit, high;
+	unsigned i;
+
+	for (i = 0; i < 8; ++i) {
+		pci_read_config_dword(dev, AMD_141b_MMIO_BASE(i), &base);
+		pci_read_config_dword(dev, AMD_141b_MMIO_HIGH(i), &high);
+
+		/* Is this slot free? */
+		if (!(base & (AMD_141b_MMIO_BASE_RE_MASK |
+			      AMD_141b_MMIO_BASE_WE_MASK)))
+			break;
+
+		base >>= 8;
+		base |= high << 24;
+
+		/* Abort if a slot already configures a 64bit BAR. */
+		if (base > 0x10000)
+			return;
+	}
+	if (i == 8)
+		return;
+
+	res = kzalloc(sizeof(*res), GFP_KERNEL);
+	if (!res)
+		return;
+
+	res->name = "PCI Bus 0000:00";
+	res->flags = IORESOURCE_PREFETCH | IORESOURCE_MEM |
+		IORESOURCE_MEM_64 | IORESOURCE_WINDOW;
+	res->start = 0x100000000ull;
+	res->end = 0xfd00000000ull - 1;
+
+	/* Just grab the free area behind system memory for this */
+	while ((conflict = request_resource_conflict(&iomem_resource, res)))
+		res->start = conflict->end + 1;
+
+	dev_info(&dev->dev, "adding root bus resource %pR\n", res);
+
+	base = ((res->start >> 8) & AMD_141b_MMIO_BASE_MMIOBASE_MASK) |
+		AMD_141b_MMIO_BASE_RE_MASK | AMD_141b_MMIO_BASE_WE_MASK;
+	limit = ((res->end + 1) >> 8) & AMD_141b_MMIO_LIMIT_MMIOLIMIT_MASK;
+	high = ((res->start >> 40) & AMD_141b_MMIO_HIGH_MMIOBASE_MASK) |
+		((((res->end + 1) >> 40) << AMD_141b_MMIO_HIGH_MMIOLIMIT_SHIFT)
+		 & AMD_141b_MMIO_HIGH_MMIOLIMIT_MASK);
+
+	pci_write_config_dword(dev, AMD_141b_MMIO_HIGH(i), high);
+	pci_write_config_dword(dev, AMD_141b_MMIO_LIMIT(i), limit);
+	pci_write_config_dword(dev, AMD_141b_MMIO_BASE(i), base);
+
+	pci_bus_add_resource(dev->bus, res, 0);
+}
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_AMD, 0x141b, pci_amd_enable_64bit_bar);
-- 
2.7.4

Re: [PATCH 4/5] x86/PCI: Enable a 64bit BAR on AMD Family 15h (Models 30h-3fh) Processors v3

[Andy Shevchenko]

On Thu, May 4, 2017 at 12:31 PM, Christian K=C3=B6nig
<deathsimple@vodafone.de> wrote:
> From: Christian K=C3=B6nig <christian.koenig@amd.com>
>
> Most BIOS don't enable this because of compatibility reasons.
>
> Manually enable a 64bit BAR of 64GB size so that we have
> enough room for PCI devices.
>
> v2: style cleanups, increase size, add resource name, set correct flags,
>     print message that windows was added
> v3: add defines for all the magic numbers, style cleanups

FWIW:
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

>
> Signed-off-by: Christian K=C3=B6nig <christian.koenig@amd.com>
> ---
>  arch/x86/pci/fixup.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++=
++++++
>  1 file changed, 69 insertions(+)
>
> diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
> index 6d52b94..1c36ed6 100644
> --- a/arch/x86/pci/fixup.c
> +++ b/arch/x86/pci/fixup.c
> @@ -571,3 +571,72 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2fc0,=
 pci_invalid_bar);
>  DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6f60, pci_invalid_bar);
>  DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fa0, pci_invalid_bar);
>  DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fc0, pci_invalid_bar);
> +
> +#define AMD_141b_MMIO_BASE(x)  (0x80 + (x) * 0x8)
> +#define AMD_141b_MMIO_BASE_RE_MASK             BIT(0)
> +#define AMD_141b_MMIO_BASE_WE_MASK             BIT(1)
> +#define AMD_141b_MMIO_BASE_MMIOBASE_MASK       GENMASK(31,8)
> +
> +#define AMD_141b_MMIO_LIMIT(x) (0x84 + (x) * 0x8)
> +#define AMD_141b_MMIO_LIMIT_MMIOLIMIT_MASK     GENMASK(31,8)
> +
> +#define AMD_141b_MMIO_HIGH(x)  (0x180 + (x) * 0x4)
> +#define AMD_141b_MMIO_HIGH_MMIOBASE_MASK       GENMASK(7,0)
> +#define AMD_141b_MMIO_HIGH_MMIOLIMIT_SHIFT     16
> +#define AMD_141b_MMIO_HIGH_MMIOLIMIT_MASK      GENMASK(23,16)
> +
> +static void pci_amd_enable_64bit_bar(struct pci_dev *dev)
> +{
> +       struct resource *res, *conflict;
> +       u32 base, limit, high;
> +       unsigned i;
> +
> +       for (i =3D 0; i < 8; ++i) {
> +               pci_read_config_dword(dev, AMD_141b_MMIO_BASE(i), &base);
> +               pci_read_config_dword(dev, AMD_141b_MMIO_HIGH(i), &high);
> +
> +               /* Is this slot free? */
> +               if (!(base & (AMD_141b_MMIO_BASE_RE_MASK |
> +                             AMD_141b_MMIO_BASE_WE_MASK)))
> +                       break;
> +
> +               base >>=3D 8;
> +               base |=3D high << 24;
> +
> +               /* Abort if a slot already configures a 64bit BAR. */
> +               if (base > 0x10000)
> +                       return;
> +       }
> +       if (i =3D=3D 8)
> +               return;
> +
> +       res =3D kzalloc(sizeof(*res), GFP_KERNEL);
> +       if (!res)
> +               return;
> +
> +       res->name =3D "PCI Bus 0000:00";
> +       res->flags =3D IORESOURCE_PREFETCH | IORESOURCE_MEM |
> +               IORESOURCE_MEM_64 | IORESOURCE_WINDOW;
> +       res->start =3D 0x100000000ull;
> +       res->end =3D 0xfd00000000ull - 1;
> +
> +       /* Just grab the free area behind system memory for this */
> +       while ((conflict =3D request_resource_conflict(&iomem_resource, r=
es)))
> +               res->start =3D conflict->end + 1;
> +
> +       dev_info(&dev->dev, "adding root bus resource %pR\n", res);
> +
> +       base =3D ((res->start >> 8) & AMD_141b_MMIO_BASE_MMIOBASE_MASK) |
> +               AMD_141b_MMIO_BASE_RE_MASK | AMD_141b_MMIO_BASE_WE_MASK;
> +       limit =3D ((res->end + 1) >> 8) & AMD_141b_MMIO_LIMIT_MMIOLIMIT_M=
ASK;
> +       high =3D ((res->start >> 40) & AMD_141b_MMIO_HIGH_MMIOBASE_MASK) =
|
> +               ((((res->end + 1) >> 40) << AMD_141b_MMIO_HIGH_MMIOLIMIT_=
SHIFT)
> +                & AMD_141b_MMIO_HIGH_MMIOLIMIT_MASK);
> +
> +       pci_write_config_dword(dev, AMD_141b_MMIO_HIGH(i), high);
> +       pci_write_config_dword(dev, AMD_141b_MMIO_LIMIT(i), limit);
> +       pci_write_config_dword(dev, AMD_141b_MMIO_BASE(i), base);
> +
> +       pci_bus_add_resource(dev->bus, res, 0);
> +}
> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_AMD, 0x141b, pci_amd_enable_64bit_=
bar);
> --
> 2.7.4
>



--=20
With Best Regards,
Andy Shevchenko

[PATCH 5/5] drm/amdgpu: resize VRAM BAR for CPU access v2

[Christian König]

From: Christian König <christian.koenig@amd.com>

Try to resize BAR0 to let CPU access all of VRAM.

v2: rebased, style cleanups, disable mem decode before resize,
    handle gmc_v9 as well, round size up to power of two.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu.h        |  1 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 37 ++++++++++++++++++++++++++++++
 drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c      |  8 ++++---
 drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c      |  8 ++++---
 drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c      | 10 ++++----
 5 files changed, 54 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 0ee4d87..ed49e92 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1884,6 +1884,7 @@ uint64_t amdgpu_ttm_tt_pte_flags(struct amdgpu_device *adev, struct ttm_tt *ttm,
 				 struct ttm_mem_reg *mem);
 void amdgpu_vram_location(struct amdgpu_device *adev, struct amdgpu_mc *mc, u64 base);
 void amdgpu_gtt_location(struct amdgpu_device *adev, struct amdgpu_mc *mc);
+void amdgpu_resize_bar0(struct amdgpu_device *adev);
 void amdgpu_ttm_set_active_vram_size(struct amdgpu_device *adev, u64 size);
 int amdgpu_ttm_init(struct amdgpu_device *adev);
 void amdgpu_ttm_fini(struct amdgpu_device *adev);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index e685ca9..523936a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -695,6 +695,43 @@ void amdgpu_gtt_location(struct amdgpu_device *adev, struct amdgpu_mc *mc)
 			mc->gtt_size >> 20, mc->gtt_start, mc->gtt_end);
 }
 
+/**
+ * amdgpu_resize_bar0 - try to resize BAR0
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * Try to resize BAR0 to make all VRAM CPU accessible.
+ */
+void amdgpu_resize_bar0(struct amdgpu_device *adev)
+{
+	u64 space_needed = roundup_pow_of_two(adev->mc.real_vram_size);
+	u32 rbar_size = order_base_2(((space_needed >> 20) | 1)) -1;
+	u16 cmd;
+	int r;
+
+	/* Free the doorbell mapping, it most likely needs to move as well */
+	amdgpu_doorbell_fini(adev);
+	pci_release_resource(adev->pdev, 2);
+
+	/* Disable memory decoding while we change the BAR addresses and size */
+	pci_read_config_word(adev->pdev, PCI_COMMAND, &cmd);
+	pci_write_config_word(adev->pdev, PCI_COMMAND,
+			      cmd & ~PCI_COMMAND_MEMORY);
+
+	r = pci_resize_resource(adev->pdev, 0, rbar_size);
+	if (r == -ENOSPC)
+		DRM_INFO("Not enough PCI address space for a large BAR.");
+	else if (r && r != -ENOTSUPP)
+		DRM_ERROR("Problem resizing BAR0 (%d).", r);
+
+	pci_write_config_word(adev->pdev, PCI_COMMAND, cmd);
+
+	/* When the doorbell BAR isn't available we have no chance of
+	 * using the device.
+	 */
+	BUG_ON(amdgpu_doorbell_init(adev));
+}
+
 /*
  * GPU helpers function.
  */
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
index a9083a1..ae71524 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
@@ -372,13 +372,15 @@ static int gmc_v7_0_mc_init(struct amdgpu_device *adev)
 		}
 		adev->mc.vram_width = numchan * chansize;
 	}
-	/* Could aper size report 0 ? */
-	adev->mc.aper_base = pci_resource_start(adev->pdev, 0);
-	adev->mc.aper_size = pci_resource_len(adev->pdev, 0);
 	/* size in MB on si */
 	adev->mc.mc_vram_size = RREG32(mmCONFIG_MEMSIZE) * 1024ULL * 1024ULL;
 	adev->mc.real_vram_size = RREG32(mmCONFIG_MEMSIZE) * 1024ULL * 1024ULL;
 
+	if (!(adev->flags & AMD_IS_APU))
+		amdgpu_resize_bar0(adev);
+	adev->mc.aper_base = pci_resource_start(adev->pdev, 0);
+	adev->mc.aper_size = pci_resource_len(adev->pdev, 0);
+
 #ifdef CONFIG_X86_64
 	if (adev->flags & AMD_IS_APU) {
 		adev->mc.aper_base = ((u64)RREG32(mmMC_VM_FB_OFFSET)) << 22;
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
index 4ac9978..1655de2 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
@@ -534,13 +534,15 @@ static int gmc_v8_0_mc_init(struct amdgpu_device *adev)
 		}
 		adev->mc.vram_width = numchan * chansize;
 	}
-	/* Could aper size report 0 ? */
-	adev->mc.aper_base = pci_resource_start(adev->pdev, 0);
-	adev->mc.aper_size = pci_resource_len(adev->pdev, 0);
 	/* size in MB on si */
 	adev->mc.mc_vram_size = RREG32(mmCONFIG_MEMSIZE) * 1024ULL * 1024ULL;
 	adev->mc.real_vram_size = RREG32(mmCONFIG_MEMSIZE) * 1024ULL * 1024ULL;
 
+	if (!(adev->flags & AMD_IS_APU))
+		amdgpu_resize_bar0(adev);
+	adev->mc.aper_base = pci_resource_start(adev->pdev, 0);
+	adev->mc.aper_size = pci_resource_len(adev->pdev, 0);
+
 #ifdef CONFIG_X86_64
 	if (adev->flags & AMD_IS_APU) {
 		adev->mc.aper_base = ((u64)RREG32(mmMC_VM_FB_OFFSET)) << 22;
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
index b9f11fa..d65728a 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
@@ -469,16 +469,18 @@ static int gmc_v9_0_mc_init(struct amdgpu_device *adev)
 	}
 	adev->mc.vram_width = numchan * chansize;
 
-	/* Could aper size report 0 ? */
-	adev->mc.aper_base = pci_resource_start(adev->pdev, 0);
-	adev->mc.aper_size = pci_resource_len(adev->pdev, 0);
 	/* size in MB on si */
 	adev->mc.mc_vram_size =
 		nbio_v6_1_get_memsize(adev) * 1024ULL * 1024ULL;
 	adev->mc.real_vram_size = adev->mc.mc_vram_size;
-	adev->mc.visible_vram_size = adev->mc.aper_size;
+
+	if (!(adev->flags & AMD_IS_APU))
+		amdgpu_resize_bar0(adev);
+	adev->mc.aper_base = pci_resource_start(adev->pdev, 0);
+	adev->mc.aper_size = pci_resource_len(adev->pdev, 0);
 
 	/* In case the PCI BAR is larger than the actual amount of vram */
+	adev->mc.visible_vram_size = adev->mc.aper_size;
 	if (adev->mc.visible_vram_size > adev->mc.real_vram_size)
 		adev->mc.visible_vram_size = adev->mc.real_vram_size;
 
-- 
2.7.4

Re: Resizeable PCI BAR support v5

[Andy Shevchenko]

On Thu, May 4, 2017 at 12:31 PM, Christian K=C3=B6nig
<deathsimple@vodafone.de> wrote:
> Hi everyone,
>
> this is the fifth incarnation of this set of patches. It enables device
> drivers to resize and most likely also relocate the PCI BAR of devices
> they manage to allow the CPU to access all of the device local memory at =
once.
>
> This is very useful for GFX device drivers where the default PCI BAR is o=
nly
> about 256MB in size for compatibility reasons, but the device easily have
> multiple gigabyte of local memory.
>
> Noteable changed compared to v4:
> 1. Patch #1 is new and a minor cleanup to the PCI code.
> 2. Some more helpers added to patch #2
> 3. We now print a note to syslog before releasing resources.
> 4. Add defines for registers and bits used to add new root hub window.
>
> I've addressed mostly every review comment I've got so far and it looks l=
ike we
> are getting closer to landing this. Any more suggestions/hints how we cou=
ld
> improve the patchset would be very welcome.
>

Thanks for an update.

I'm going to comment individual patches.

Just for the future, please use versioning in the patches themselves
(hint: -vX to git-format-patch).

--=20
With Best Regards,
Andy Shevchenko