drm/amdgpu: add invalidate_page callback for userptrs

Otherwise we can run into problems with the writeback code.
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c

@@ -106,42 +106,23 @@ static void amdgpu_mn_release(struct mmu_notifier *mn,
 }
 
 /**
- * amdgpu_mn_invalidate_range_start - callback to notify about mm change
+ * amdgpu_mn_invalidate_node - unmap all BOs of a node
  *
- * @mn: our notifier
- * @mn: the mm this callback is about
- * @start: start of updated range
- * @end: end of updated range
+ * @node: the node with the BOs to unmap
  *
- * We block for all BOs between start and end to be idle and
- * unmap them by move them into system domain again.
+ * We block for all BOs and unmap them by move them
+ * into system domain again.
  */
-static void amdgpu_mn_invalidate_range_start(struct mmu_notifier *mn,
-					     struct mm_struct *mm,
+static void amdgpu_mn_invalidate_node(struct amdgpu_mn_node *node,
 				      unsigned long start,
 				      unsigned long end)
 {
-	struct amdgpu_mn *rmn = container_of(mn, struct amdgpu_mn, mn);
-	struct interval_tree_node *it;
-
-	/* notification is exclusive, but interval is inclusive */
-	end -= 1;
-
-	mutex_lock(&rmn->lock);
-
-	it = interval_tree_iter_first(&rmn->objects, start, end);
-	while (it) {
-		struct amdgpu_mn_node *node;
 	struct amdgpu_bo *bo;
 	long r;
 
-		node = container_of(it, struct amdgpu_mn_node, it);
-		it = interval_tree_iter_next(it, start, end);
-
 	list_for_each_entry(bo, &node->bos, mn_list) {
 
-			if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, start,
-							  end))
+		if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, start, end))
 			continue;
 
 		r = amdgpu_bo_reserve(bo, true);
@@ -162,6 +143,70 @@ static void amdgpu_mn_invalidate_range_start(struct mmu_notifier *mn,
 
 		amdgpu_bo_unreserve(bo);
 	}
+}
+
+/**
+ * amdgpu_mn_invalidate_page - callback to notify about mm change
+ *
+ * @mn: our notifier
+ * @mn: the mm this callback is about
+ * @address: address of invalidate page
+ *
+ * Invalidation of a single page. Blocks for all BOs mapping it
+ * and unmap them by move them into system domain again.
+ */
+static void amdgpu_mn_invalidate_page(struct mmu_notifier *mn,
+				      struct mm_struct *mm,
+				      unsigned long address)
+{
+	struct amdgpu_mn *rmn = container_of(mn, struct amdgpu_mn, mn);
+	struct interval_tree_node *it;
+
+	mutex_lock(&rmn->lock);
+
+	it = interval_tree_iter_first(&rmn->objects, address, address);
+	if (it) {
+		struct amdgpu_mn_node *node;
+
+		node = container_of(it, struct amdgpu_mn_node, it);
+		amdgpu_mn_invalidate_node(node, address, address);
+	}
+
+	mutex_unlock(&rmn->lock);
+}
+
+/**
+ * amdgpu_mn_invalidate_range_start - callback to notify about mm change
+ *
+ * @mn: our notifier
+ * @mn: the mm this callback is about
+ * @start: start of updated range
+ * @end: end of updated range
+ *
+ * We block for all BOs between start and end to be idle and
+ * unmap them by move them into system domain again.
+ */
+static void amdgpu_mn_invalidate_range_start(struct mmu_notifier *mn,
+					     struct mm_struct *mm,
+					     unsigned long start,
+					     unsigned long end)
+{
+	struct amdgpu_mn *rmn = container_of(mn, struct amdgpu_mn, mn);
+	struct interval_tree_node *it;
+
+	/* notification is exclusive, but interval is inclusive */
+	end -= 1;
+
+	mutex_lock(&rmn->lock);
+
+	it = interval_tree_iter_first(&rmn->objects, start, end);
+	while (it) {
+		struct amdgpu_mn_node *node;
+
+		node = container_of(it, struct amdgpu_mn_node, it);
+		it = interval_tree_iter_next(it, start, end);
+
+		amdgpu_mn_invalidate_node(node, start, end);
 	}
 
 	mutex_unlock(&rmn->lock);
@@ -169,6 +214,7 @@ static void amdgpu_mn_invalidate_range_start(struct mmu_notifier *mn,
 
 static const struct mmu_notifier_ops amdgpu_mn_ops = {
 	.release = amdgpu_mn_release,
+	.invalidate_page = amdgpu_mn_invalidate_page,
 	.invalidate_range_start = amdgpu_mn_invalidate_range_start,
 };