Unverified Commit 899d3a3c authored by Nirmoy Das's avatar Nirmoy Das Committed by Maxime Ripard
Browse files

drm/drm_vma_manager: Add drm_vma_node_allow_once() 



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: default avatarChris Wilson <chris.p.wilson@intel.com>
Signed-off-by: default avatarNirmoy Das <nirmoy.das@intel.com>
Reviewed-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: default avatarAndi Shyti <andi.shyti@linux.intel.com>
Link: https://lore.kernel.org/r/20230117175236.22317-1-nirmoy.das@intel.com


Signed-off-by: default avatarMaxime Ripard <maxime@cerno.tech>
parent 2293a73a

drivers/gpu/drm/drm_vma_manager.c

+54 −22
Original line number Diff line number Diff line
@@ -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;
@@ -282,6 +263,7 @@ 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) {

			if (ref_counted)

				entry->vm_count++;

			goto unlock;

		} else if (tag > entry->vm_tag) {
@@ -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

include/drm/drm_vma_manager.h

+1 −0
Original line number Diff line number Diff line
@@ -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,