[PATCH v3 05/15] drm/i915: Defer default hardware context initialisation until first open

yu.dai
2015-04-17T21:23:06Z

From: Dave Gordon <david.s.gordon@intel.com>

In order to fully initialise the default contexts, we have to execute
batchbuffer commands on the GPU engines. But we can't do that until any
required firmware has been loaded, which may not be possible during
driver load, because the filesystem(s) containing the firmware may not
be mounted until later.

Therefore, we now allow the first call to the firmware-loading code to
return -EAGAIN to indicate that it's not yet ready, and that it should
be retried when the device is first opened from user code, by which
time we expect that all required filesystems will have been mounted.
The late-retry code will then re-attempt to load the firmware if the
early attempt failed.

Issue: VIZ-4884
Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Signed-off-by: Alex Dai <yu.dai@intel.com>
---
drivers/gpu/drm/i915/i915_drv.h | 1 +
drivers/gpu/drm/i915/i915_gem.c | 9 ++++++++-
drivers/gpu/drm/i915/i915_gem_context.c | 35 ++++++++++++++++++++++++++++-----
drivers/gpu/drm/i915/intel_guc.h | 2 +-
drivers/gpu/drm/i915/intel_guc_loader.c | 25 +++++++++++++++++++++--
5 files changed, 63 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 235fc08..d128ac4 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1760,6 +1760,7 @@ struct drm_i915_private {
/* hda/i915 audio component */
bool audio_component_registered;

+ bool contexts_ready;
uint32_t hw_context_size;
struct list_head context_list;

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 44154fe..b7bd288 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4888,8 +4888,15 @@ i915_gem_init_hw(struct drm_device *dev)
i915_gem_cleanup_ringbuffer(dev);
}

+ /* We can't enable contexts until all firmware is loaded */
+ ret = intel_guc_load_ucode(dev, false);
+ if (ret == -EAGAIN)
+ return 0; /* too early */
+
ret = i915_gem_context_enable(dev_priv);
- if (ret && ret != -EIO) {
+ if (ret == 0) {
+ dev_priv->contexts_ready = true;
+ } else if (ret && ret != -EIO) {
DRM_ERROR("Context enable failed %d\n", ret);
i915_gem_cleanup_ringbuffer(dev);

diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index e4c57a3..3795df2 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -447,23 +447,48 @@ static int context_idr_cleanup(int id, void *p, void *data)
return 0;
}

+/* Complete any late initialisation here */
+static int i915_gem_context_first_open(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ int ret;
+
+ /* We can't enable contexts until all firmware is loaded */
+ ret = intel_guc_load_ucode(dev, true);
+ WARN_ON(ret == -EAGAIN);
+
+ ret = i915_gem_context_enable(dev_priv);
+ if (ret == 0)
+ dev_priv->contexts_ready = true;
+ return ret;
+}
+
int i915_gem_context_open(struct drm_device *dev, struct drm_file *file)
{
+ struct drm_i915_private *dev_priv = dev->dev_private;
struct drm_i915_file_private *file_priv = file->driver_priv;
struct intel_context *ctx;
+ int ret = 0;

idr_init(&file_priv->context_idr);

mutex_lock(&dev->struct_mutex);
- ctx = i915_gem_create_context(dev, file_priv);
+
+ if (!dev_priv->contexts_ready)
+ ret = i915_gem_context_first_open(dev);
+
+ if (ret == 0) {
+ ctx = i915_gem_create_context(dev, file_priv);
+ if (IS_ERR(ctx))
+ ret = PTR_ERR(ctx);
+ }
+
mutex_unlock(&dev->struct_mutex);

- if (IS_ERR(ctx)) {
+ if (ret)
idr_destroy(&file_priv->context_idr);
- return PTR_ERR(ctx);
- }

- return 0;
+ return ret;
}

void i915_gem_context_close(struct drm_device *dev, struct drm_file *file)
diff --git a/drivers/gpu/drm/i915/intel_guc.h b/drivers/gpu/drm/i915/intel_guc.h
index 4fafcec..0a73122 100644
--- a/drivers/gpu/drm/i915/intel_guc.h
+++ b/drivers/gpu/drm/i915/intel_guc.h
@@ -96,7 +96,7 @@ struct intel_guc {
GUC_ENABLE_READ_CACHE_FOR_WOPCM_DATA)

/* intel_guc_loader.c */
-extern int intel_guc_load_ucode(struct drm_device *dev);
+extern int intel_guc_load_ucode(struct drm_device *dev, bool wait);
extern void intel_guc_ucode_fini(struct drm_device *dev);
extern void intel_guc_ucode_init(struct drm_device *dev);

diff --git a/drivers/gpu/drm/i915/intel_guc_loader.c b/drivers/gpu/drm/i915/intel_guc_loader.c
index a999044..a17f210 100644
--- a/drivers/gpu/drm/i915/intel_guc_loader.c
+++ b/drivers/gpu/drm/i915/intel_guc_loader.c
@@ -246,24 +246,45 @@ out:
* intel_guc_load_ucode() - load ucode to hw
*
* Called from gem_init_hw() during driver loading and also after a GPU reset.
+
* Check that the firmware fetching process has succeeded, and if so transfer
* the loaded image to the hardware.
+ *
+ * However, there are a few checks to do first. The very first call should have
+ * (wait == FALSE), but the fetch_state will still be PENDING as the firmware may
+ * not be available that early. Therefore, on this first call, we just return.
+ *
+ * The second call should come from the first open of the device (wait == TRUE).
+ * This is a good time to load the firmware into the device, as by this point it
+ * must be available.
+ *
+ * Any subsequent calls are expected to have wait == FALSE, and indicate that the
+ * hardware has been reset and so the firmware should be reloaded.
*/
-int intel_guc_load_ucode(struct drm_device *dev)
+int intel_guc_load_ucode(struct drm_device *dev, bool wait)
{
struct drm_i915_private *dev_priv = dev->dev_private;
struct intel_uc_fw *guc_fw = &dev_priv->guc.guc_fw;
int err;

+ if (!HAS_GUC_UCODE(dev))
+ return 0;
+
+ DRM_DEBUG_DRIVER("GuC: wait %d, fetch status %d, load status %d\n",
+ wait, guc_fw->uc_fw_fetch_status, guc_fw->uc_fw_load_status);
+
+ if (guc_fw->uc_fw_fetch_status == INTEL_UC_FIRMWARE_PENDING && !wait)
+ return -EAGAIN;
+
guc_fw->uc_fw_load_status = INTEL_UC_FIRMWARE_NONE;
if (guc_fw->uc_fw_fetch_status == INTEL_UC_FIRMWARE_NONE)
return 0;

- guc_fw->uc_fw_load_status = INTEL_UC_FIRMWARE_PENDING;
err = intel_uc_fw_check(dev, guc_fw);
if (err)
goto fail;

+ guc_fw->uc_fw_load_status = INTEL_UC_FIRMWARE_PENDING;
err = guc_load_ucode(dev);
if (err)
goto fail;
--
1.9.1