[Intel-gfx] [PATCH 2/2 v2] drm/i915: mark GEM objects dirty after overwriting their contents

[Dave Gordon]

In a few places, we fill a GEM object with data, or overwrite some
portion of its contents other than a single page. In such cases, we
should mark the object dirty so that its pages in the pagecache are
written to backing store (rather than discarded) if the object is
evicted due to memory pressure.

The cases where only a single page is touched are dealt with in a
separate patch.

This incorporates and supercedes Alex Dai's earlier patch
[PATCH v1] drm/i915/guc: Fix a fw content lost issue after it is evicted

Signed-off-by: Dave Gordon <david.s.gordon at intel.com>
Cc: Alex Dai <yu.dai at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_cmd_parser.c | 3 +++
 drivers/gpu/drm/i915/i915_gem.c        | 5 ++++-
 drivers/gpu/drm/i915/intel_lrc.c       | 2 +-
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c
index 814d894..81a4fa2 100644
--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
+++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
@@ -946,6 +946,9 @@ static u32 *copy_batch(struct drm_i915_gem_object *dest_obj,
 
 	memcpy(dst, src, batch_len);
 
+	/* After writing on the dest_obj, its backing store is out-of-date */
+	dest_obj->dirty = 1;
+
 unmap_src:
 	vunmap(src_base);
 unpin_src:
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 06a5f39..81a770f 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -937,7 +937,6 @@ i915_gem_shmem_pwrite(struct drm_device *dev,
 	i915_gem_object_pin_pages(obj);
 
 	offset = args->offset;
-	obj->dirty = 1;
 
 	for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents,
 			 offset >> PAGE_SHIFT) {
@@ -1074,6 +1073,9 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
 		goto out;
 	}
 
+	/* Object backing store will be out of date hereafter */
+	obj->dirty = 1;
+
 	trace_i915_gem_object_pwrite(obj, args->offset, args->size);
 
 	ret = -EFAULT;
@@ -5224,6 +5226,7 @@ i915_gem_object_create_from_data(struct drm_device *dev,
 	i915_gem_object_pin_pages(obj);
 	sg = obj->pages;
 	bytes = sg_copy_from_buffer(sg->sgl, sg->nents, (void *)data, size);
+	obj->dirty = 1;		/* Backing store is now out of date */
 	i915_gem_object_unpin_pages(obj);
 
 	if (WARN_ON(bytes != size)) {
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index ceccecc..c7520b7 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1030,7 +1030,7 @@ static int intel_lr_context_do_pin(struct intel_engine_cs *ring,
 	if (ret)
 		goto unpin_ctx_obj;
 
-	ctx_obj->dirty = true;
+	ctx_obj->dirty = 1;
 
 	/* Invalidate GuC TLB. */
 	if (i915.enable_guc_submission)
-- 
1.9.1