[PATCH v3 5/6] drm/i915: Don't back up pinned LMEM context images and rings during suspend

[Thomas Hellström]

Pinned context images are now reset during resume. Don't back them up,
and assuming that rings can be assumed empty at suspend, don't back them
up either.

Introduce a new object flag, I915_BO_ALLOC_PM_VOLATILE meaning that an
object is allowed to lose its content on suspend.

v3:
- Slight documentation clarification (Matthew Auld)

Signed-off-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
---
 .../gpu/drm/i915/gem/i915_gem_object_types.h    | 17 ++++++++++-------
 drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c      |  3 +++
 drivers/gpu/drm/i915/gt/intel_lrc.c             |  3 ++-
 drivers/gpu/drm/i915/gt/intel_ring.c            |  3 ++-
 4 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
index 734cc8e16481..118691ce81d7 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
@@ -288,16 +288,19 @@ struct drm_i915_gem_object {
 	I915_SELFTEST_DECLARE(struct list_head st_link);
 
 	unsigned long flags;
-#define I915_BO_ALLOC_CONTIGUOUS BIT(0)
-#define I915_BO_ALLOC_VOLATILE   BIT(1)
-#define I915_BO_ALLOC_CPU_CLEAR  BIT(2)
-#define I915_BO_ALLOC_USER       BIT(3)
+#define I915_BO_ALLOC_CONTIGUOUS  BIT(0)
+#define I915_BO_ALLOC_VOLATILE    BIT(1)
+#define I915_BO_ALLOC_CPU_CLEAR   BIT(2)
+#define I915_BO_ALLOC_USER        BIT(3)
+/* Object is allowed to lose its contents on suspend / resume, even if pinned */
+#define I915_BO_ALLOC_PM_VOLATILE BIT(4)
 #define I915_BO_ALLOC_FLAGS (I915_BO_ALLOC_CONTIGUOUS | \
 			     I915_BO_ALLOC_VOLATILE | \
 			     I915_BO_ALLOC_CPU_CLEAR | \
-			     I915_BO_ALLOC_USER)
-#define I915_BO_READONLY         BIT(4)
-#define I915_TILING_QUIRK_BIT    5 /* unknown swizzling; do not release! */
+			     I915_BO_ALLOC_USER | \
+			     I915_BO_ALLOC_PM_VOLATILE)
+#define I915_BO_READONLY          BIT(5)
+#define I915_TILING_QUIRK_BIT     6 /* unknown swizzling; do not release! */
 
 	/**
 	 * @mem_flags - Mutable placement-related flags
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c
index 30c13cfe851c..a87419755d43 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c
@@ -60,6 +60,9 @@ static int i915_ttm_backup(struct i915_gem_apply_to_region *apply,
 	if (!pm_apply->backup_pinned)
 		return 0;
 
+	if (obj->flags & I915_BO_ALLOC_PM_VOLATILE)
+		return 0;
+
 	backup = i915_gem_object_create_shmem(i915, obj->base.size);
 	if (IS_ERR(backup))
 		return PTR_ERR(backup);
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 6ba8daea2f56..3ef9eaf8c50e 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -942,7 +942,8 @@ __lrc_alloc_state(struct intel_context *ce, struct intel_engine_cs *engine)
 		context_size += PAGE_SIZE;
 	}
 
-	obj = i915_gem_object_create_lmem(engine->i915, context_size, 0);
+	obj = i915_gem_object_create_lmem(engine->i915, context_size,
+					  I915_BO_ALLOC_PM_VOLATILE);
 	if (IS_ERR(obj))
 		obj = i915_gem_object_create_shmem(engine->i915, context_size);
 	if (IS_ERR(obj))
diff --git a/drivers/gpu/drm/i915/gt/intel_ring.c b/drivers/gpu/drm/i915/gt/intel_ring.c
index 7c4d5158e03b..2fdd52b62092 100644
--- a/drivers/gpu/drm/i915/gt/intel_ring.c
+++ b/drivers/gpu/drm/i915/gt/intel_ring.c
@@ -112,7 +112,8 @@ static struct i915_vma *create_ring_vma(struct i915_ggtt *ggtt, int size)
 	struct drm_i915_gem_object *obj;
 	struct i915_vma *vma;
 
-	obj = i915_gem_object_create_lmem(i915, size, I915_BO_ALLOC_VOLATILE);
+	obj = i915_gem_object_create_lmem(i915, size, I915_BO_ALLOC_VOLATILE |
+					  I915_BO_ALLOC_PM_VOLATILE);
 	if (IS_ERR(obj) && i915_ggtt_has_aperture(ggtt))
 		obj = i915_gem_object_create_stolen(i915, size);
 	if (IS_ERR(obj))
-- 
2.31.1