drm/vmwgfx: Be more restrictive when dirtying resources

Currently we flag resources as dirty (GPU contents not yet read back to
the backing MOB) whenever they have been part of a command stream.
Obviously many resources can't be dirty and others can only be dirty when
written to by the GPU. That is when they are either bound to the context as
render-targets, depth-stencil, copy / clear destinations and
stream-output targets, or similarly when there are corresponding views into
them.
So mark resources dirty only in these special cases. Context- and cotable
resources are always marked dirty when referenced.
This is important for upcoming emulated coherent memory, since we can avoid
issuing automatic readbacks to non-dirty resources when the CPU tries to
access part of the backing MOB.

Testing: Unigine Heaven with max GPU memory set to 256MB resulting in
heavy resource thrashing.
---
v2: Addressed review comments by Deepak Rawat.
v3: Added some documentation

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Deepak Rawat <drawat@vmware.com>

1 files changed, 7 insertions, 5 deletions

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c b/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
index 096c2941a8e4..1a65008a27b2 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
@@ -111,7 +111,7 @@ struct vmw_stdu_update_gb_image {
  */
 struct vmw_screen_target_display_unit {
 	struct vmw_display_unit base;
-	const struct vmw_surface *display_srf;
+	struct vmw_surface *display_srf;
 	enum stdu_content_type content_fb_type;
 	s32 display_width, display_height;
 
@@ -533,6 +533,7 @@ static void vmw_stdu_bo_fifo_commit(struct vmw_kms_dirty *dirty)
 
 	vmw_fifo_commit(dirty->dev_priv, sizeof(*cmd) + blit_size);
 
+	stdu->display_srf->res.res_dirty = true;
 	ddirty->left = ddirty->top = S32_MAX;
 	ddirty->right = ddirty->bottom = S32_MIN;
 }
@@ -629,9 +630,8 @@ static void vmw_stdu_bo_cpu_commit(struct vmw_kms_dirty *dirty)
 		region.x2 = diff.rect.x2;
 		region.y1 = diff.rect.y1;
 		region.y2 = diff.rect.y2;
-		ret = vmw_kms_update_proxy(
-			(struct vmw_resource *) &stdu->display_srf->res,
-			(const struct drm_clip_rect *) &region, 1, 1);
+		ret = vmw_kms_update_proxy(&stdu->display_srf->res, &region,
+					   1, 1);
 		if (ret)
 			goto out_cleanup;
 
@@ -820,6 +820,7 @@ static void vmw_kms_stdu_surface_fifo_commit(struct vmw_kms_dirty *dirty)
 		cmd->body.dest.sid = stdu->display_srf->res.id;
 		update = (struct vmw_stdu_update *) &blit[dirty->num_hits];
 		commit_size = sizeof(*cmd) + blit_size + sizeof(*update);
+		stdu->display_srf->res.res_dirty = true;
 	} else {
 		update = dirty->cmd;
 		commit_size = sizeof(*update);
@@ -876,7 +877,8 @@ int vmw_kms_stdu_surface_dirty(struct vmw_private *dev_priv,
 	if (!srf)
 		srf = &vfbs->surface->res;
 
-	ret = vmw_validation_add_resource(&val_ctx, srf, 0, NULL, NULL);
+	ret = vmw_validation_add_resource(&val_ctx, srf, 0, VMW_RES_DIRTY_NONE,
+					  NULL, NULL);
 	if (ret)
 		return ret;