[Intel-gfx] [PATCH v2 2/4] drm/i915: Update domain tracking for GEM objects on hibernation

[Chris Wilson]

When creating the hibernation image, the CPU will read the pages of all
objects and thus conflict with our domain tracking. We need to update
our domain tracking to accurately reflect the state on restoration.

v2: Perform the domain tracking inside freeze, before the image is
written, rather than upon restoration.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Imre Deak <imre.deak at intel.com>
Cc: David Weinehall <david.weinehall at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c | 12 +++++++++++-
 drivers/gpu/drm/i915/i915_drv.h |  2 ++
 drivers/gpu/drm/i915/i915_gem.c | 28 ++++++++++++++++++++++++++++
 3 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 6a2e7f84276b..dba03c026151 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1123,7 +1123,17 @@ static int i915_pm_freeze(struct device *dev)
 
 static int i915_pm_freeze_late(struct device *dev)
 {
-	return i915_pm_suspend_late(dev);
+	int ret;
+
+	ret = i915_pm_suspend_late(dev);
+	if (ret)
+		return ret;
+
+	ret = i915_gem_freeze_late(dev_to_i915(dev));
+	if (ret)
+		return ret;
+
+	return 0;
 }
 
 /* thaw: called after creating the hibernation image, but before turning off. */
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 7a0b51301337..0a4255fa8895 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2961,6 +2961,8 @@ int i915_gem_wait_ioctl(struct drm_device *dev, void *data,
 void i915_gem_load_init(struct drm_device *dev);
 void i915_gem_load_cleanup(struct drm_device *dev);
 void i915_gem_load_init_fences(struct drm_i915_private *dev_priv);
+int i915_gem_freeze_late(struct drm_i915_private *dev_priv);
+
 void *i915_gem_object_alloc(struct drm_device *dev);
 void i915_gem_object_free(struct drm_i915_gem_object *obj);
 void i915_gem_object_init(struct drm_i915_gem_object *obj,
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index be75689455b2..7bd670e34ee5 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -5053,6 +5053,34 @@ void i915_gem_load_cleanup(struct drm_device *dev)
 	kmem_cache_destroy(dev_priv->objects);
 }
 
+int i915_gem_freeze_late(struct drm_i915_private *dev_priv)
+{
+	struct drm_i915_gem_object *obj;
+
+	/* Called just before we write the hibernation image.
+	 *
+	 * We need to update the domain tracking to reflect that the CPU
+	 * will be accessing all the pages to create and restore from the
+	 * hibernation, and so upon restoration those pages will be in the
+	 * CPU domain.
+	 *
+	 * To make sure the hibernation image contains the latest state,
+	 * we update that state just before writing out the image.
+	 */
+
+	list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_list) {
+		obj->base.read_domains = I915_GEM_DOMAIN_CPU;
+		obj->base.write_domain = I915_GEM_DOMAIN_CPU;
+	}
+
+	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
+		obj->base.read_domains = I915_GEM_DOMAIN_CPU;
+		obj->base.write_domain = I915_GEM_DOMAIN_CPU;
+	}
+
+	return 0;
+}
+
 void i915_gem_release(struct drm_device *dev, struct drm_file *file)
 {
 	struct drm_i915_file_private *file_priv = file->driver_priv;
-- 
2.8.1