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, 0 deletions

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_validation.h b/drivers/gpu/drm/vmwgfx/vmwgfx_validation.h
index 3b396fea40d7..523f6ac5c335 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_validation.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_validation.h
@@ -33,6 +33,10 @@
 #include <linux/ww_mutex.h>
 #include <drm/ttm/ttm_execbuf_util.h>
 
+#define VMW_RES_DIRTY_NONE 0
+#define VMW_RES_DIRTY_SET BIT(0)
+#define VMW_RES_DIRTY_CLEAR BIT(1)
+
 /**
  * struct vmw_validation_mem - Custom interface to provide memory reservations
  * for the validation code.
@@ -237,6 +241,7 @@ void vmw_validation_unref_lists(struct vmw_validation_context *ctx);
 int vmw_validation_add_resource(struct vmw_validation_context *ctx,
 				struct vmw_resource *res,
 				size_t priv_size,
+				u32 dirty,
 				void **p_node,
 				bool *first_usage);
 void vmw_validation_drop_ht(struct vmw_validation_context *ctx);
@@ -261,4 +266,6 @@ void *vmw_validation_mem_alloc(struct vmw_validation_context *ctx,
 int vmw_validation_preload_bo(struct vmw_validation_context *ctx);
 int vmw_validation_preload_res(struct vmw_validation_context *ctx,
 			       unsigned int size);
+void vmw_validation_res_set_dirty(struct vmw_validation_context *ctx,
+				  void *val_private, u32 dirty);
 #endif