drm: add memory clean flag.

When the mapping is clean this flag will be set. This can be used
by a driver to save migrating and allocating pages for an object
that will first be used in VRAM.

4 files changed, 18 insertions, 2 deletions

diff --git a/linux-core/drm_bo.c b/linux-core/drm_bo.c
index 09b3fa39..ec63fa2a 100644
--- a/linux-core/drm_bo.c
+++ b/linux-core/drm_bo.c
@@ -1170,6 +1170,9 @@ out_unlock:
 		DRM_FLAG_MASKED(bo->priv_flags, _DRM_BO_FLAG_UNFENCED,
 				_DRM_BO_FLAG_UNFENCED);
 	}
+	/* clear the clean flags */
+	bo->mem.flags &= ~DRM_BO_FLAG_CLEAN;
+
 	mutex_unlock(&dev->struct_mutex);
 	mutex_unlock(&bm->evict_mutex);
 	return ret;
@@ -1493,12 +1496,14 @@ int drm_buffer_object_create(struct drm_device *dev,
 	bo->buffer_start = buffer_start & PAGE_MASK;
 	bo->priv_flags = 0;
 	bo->mem.flags = (DRM_BO_FLAG_MEM_LOCAL | DRM_BO_FLAG_CACHED |
-			 DRM_BO_FLAG_MAPPABLE);
+			 DRM_BO_FLAG_MAPPABLE | DRM_BO_FLAG_CLEAN);
 	bo->mem.proposed_flags = 0;
 	atomic_inc(&bm->count);
 	/*
 	 * Use drm_bo_modify_proposed_flags to error-check the proposed flags
 	 */
+	flags |= DRM_BO_FLAG_CLEAN; /* or in the clean flag */
+
 	ret = drm_bo_modify_proposed_flags (bo, flags, flags);
 	if (ret)
 		goto out_err;
diff --git a/linux-core/drm_bo_move.c b/linux-core/drm_bo_move.c
index 5c290af2..e81967fd 100644
--- a/linux-core/drm_bo_move.c
+++ b/linux-core/drm_bo_move.c
@@ -562,6 +562,9 @@ int drm_bo_kmap(struct drm_buffer_object *bo, unsigned long start_page,
 	if (ret)
 		return ret;
 
+	/* clear the clean flags */
+	bo->mem.flags &= ~DRM_BO_FLAG_CLEAN;
+
 	if (bus_size == 0) {
 		return drm_bo_kmap_ttm(bo, start_page, num_pages, map);
 	} else {
diff --git a/linux-core/drm_objects.h b/linux-core/drm_objects.h
index 925b4d67..3eb8b902 100644
--- a/linux-core/drm_objects.h
+++ b/linux-core/drm_objects.h
@@ -146,6 +146,12 @@ struct drm_fence_arg {
 #define DRM_BO_FLAG_TILE           (1ULL << 15)
 
 /*
+ * Buffer has been mapped or touched since creation
+ * for VRAM we don't need to migrate, just fill with 0s for non-dirty
+ */
+#define DRM_BO_FLAG_CLEAN  (1ULL << 16)
+
+/*
  * Memory type flags that can be or'ed together in the mask, but only
  * one appears in flags.
  */
@@ -208,7 +214,6 @@ struct drm_fence_arg {
  */
 #define DRM_BO_HINT_PRESUMED_OFFSET 0x00000010
 
-
 #define DRM_BO_MEM_LOCAL 0
 #define DRM_BO_MEM_TT 1
 #define DRM_BO_MEM_VRAM 2
diff --git a/linux-core/drm_vm.c b/linux-core/drm_vm.c
index 0aabf943..48d7b057 100644
--- a/linux-core/drm_vm.c
+++ b/linux-core/drm_vm.c
@@ -792,6 +792,9 @@ static void drm_bo_vm_open_locked(struct vm_area_struct *vma)
 {
 	struct drm_buffer_object *bo = (struct drm_buffer_object *) vma->vm_private_data;
 
+	/* clear the clean flags */
+	bo->mem.flags &= ~DRM_BO_FLAG_CLEAN;
+
 	drm_vm_open_locked(vma);
 	atomic_inc(&bo->usage);
 #ifdef DRM_ODD_MM_COMPAT