From: Nirmoy Das nirmoy.das@intel.com
[ Upstream commit 899d3a3c19ac0e5da013ce34833dccb97d19b5e4 ]
Currently there is no easy way for a drm driver to safely check and allow drm_vma_offset_node for a drm file just once. Allow drm drivers to call non-refcounted version of drm_vma_node_allow() so that a driver doesn't need to keep track of each drm_vma_node_allow() to call subsequent drm_vma_node_revoke() to prevent memory leak.
Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com Cc: Maxime Ripard mripard@kernel.org Cc: Thomas Zimmermann tzimmermann@suse.de Cc: David Airlie airlied@gmail.com Cc: Daniel Vetter daniel@ffwll.ch Cc: Tvrtko Ursulin tvrtko.ursulin@linux.intel.com Cc: Andi Shyti andi.shyti@linux.intel.com
Suggested-by: Chris Wilson chris.p.wilson@intel.com Signed-off-by: Nirmoy Das nirmoy.das@intel.com Reviewed-by: Tvrtko Ursulin tvrtko.ursulin@intel.com Reviewed-by: Andi Shyti andi.shyti@linux.intel.com Link: https://lore.kernel.org/r/20230117175236.22317-1-nirmoy.das@intel.com Signed-off-by: Maxime Ripard maxime@cerno.tech Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/drm_vma_manager.c | 76 ++++++++++++++++++++++--------- include/drm/drm_vma_manager.h | 1 + 2 files changed, 55 insertions(+), 22 deletions(-)
diff --git a/drivers/gpu/drm/drm_vma_manager.c b/drivers/gpu/drm/drm_vma_manager.c index 7de37f8c68fd..83229a031af0 100644 --- a/drivers/gpu/drm/drm_vma_manager.c +++ b/drivers/gpu/drm/drm_vma_manager.c @@ -240,27 +240,8 @@ void drm_vma_offset_remove(struct drm_vma_offset_manager *mgr, } EXPORT_SYMBOL(drm_vma_offset_remove);
-/** - * drm_vma_node_allow - Add open-file to list of allowed users - * @node: Node to modify - * @tag: Tag of file to remove - * - * Add @tag to the list of allowed open-files for this node. If @tag is - * already on this list, the ref-count is incremented. - * - * The list of allowed-users is preserved across drm_vma_offset_add() and - * drm_vma_offset_remove() calls. You may even call it if the node is currently - * not added to any offset-manager. - * - * You must remove all open-files the same number of times as you added them - * before destroying the node. Otherwise, you will leak memory. - * - * This is locked against concurrent access internally. - * - * RETURNS: - * 0 on success, negative error code on internal failure (out-of-mem) - */ -int drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *tag) +static int vma_node_allow(struct drm_vma_offset_node *node, + struct drm_file *tag, bool ref_counted) { struct rb_node **iter; struct rb_node *parent = NULL; @@ -282,7 +263,8 @@ int drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *tag) entry = rb_entry(*iter, struct drm_vma_offset_file, vm_rb);
if (tag == entry->vm_tag) { - entry->vm_count++; + if (ref_counted) + entry->vm_count++; goto unlock; } else if (tag > entry->vm_tag) { iter = &(*iter)->rb_right; @@ -307,8 +289,58 @@ int drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *tag) kfree(new); return ret; } + +/** + * drm_vma_node_allow - Add open-file to list of allowed users + * @node: Node to modify + * @tag: Tag of file to remove + * + * Add @tag to the list of allowed open-files for this node. If @tag is + * already on this list, the ref-count is incremented. + * + * The list of allowed-users is preserved across drm_vma_offset_add() and + * drm_vma_offset_remove() calls. You may even call it if the node is currently + * not added to any offset-manager. + * + * You must remove all open-files the same number of times as you added them + * before destroying the node. Otherwise, you will leak memory. + * + * This is locked against concurrent access internally. + * + * RETURNS: + * 0 on success, negative error code on internal failure (out-of-mem) + */ +int drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *tag) +{ + return vma_node_allow(node, tag, true); +} EXPORT_SYMBOL(drm_vma_node_allow);
+/** + * drm_vma_node_allow_once - Add open-file to list of allowed users + * @node: Node to modify + * @tag: Tag of file to remove + * + * Add @tag to the list of allowed open-files for this node. + * + * The list of allowed-users is preserved across drm_vma_offset_add() and + * drm_vma_offset_remove() calls. You may even call it if the node is currently + * not added to any offset-manager. + * + * This is not ref-counted unlike drm_vma_node_allow() hence drm_vma_node_revoke() + * should only be called once after this. + * + * This is locked against concurrent access internally. + * + * RETURNS: + * 0 on success, negative error code on internal failure (out-of-mem) + */ +int drm_vma_node_allow_once(struct drm_vma_offset_node *node, struct drm_file *tag) +{ + return vma_node_allow(node, tag, false); +} +EXPORT_SYMBOL(drm_vma_node_allow_once); + /** * drm_vma_node_revoke - Remove open-file from list of allowed users * @node: Node to modify diff --git a/include/drm/drm_vma_manager.h b/include/drm/drm_vma_manager.h index 4f8c35206f7c..6c2a2f21dbf0 100644 --- a/include/drm/drm_vma_manager.h +++ b/include/drm/drm_vma_manager.h @@ -74,6 +74,7 @@ void drm_vma_offset_remove(struct drm_vma_offset_manager *mgr, struct drm_vma_offset_node *node);
int drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *tag); +int drm_vma_node_allow_once(struct drm_vma_offset_node *node, struct drm_file *tag); void drm_vma_node_revoke(struct drm_vma_offset_node *node, struct drm_file *tag); bool drm_vma_node_is_allowed(struct drm_vma_offset_node *node,