drm/drv: Add drmm managed registration helper for dmem cgroups.

Drivers will need to register dmem regions at probe time, so let's
give them a drm-managed helper.

Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20241204134410.1161769-3-dev@lankhorst.se
Signed-off-by: Maxime Ripard <mripard@kernel.org>

1 files changed, 32 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index c2c172eb25df..3cf440eee8a2 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -26,6 +26,7 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
+#include <linux/cgroup_dmem.h>
 #include <linux/debugfs.h>
 #include <linux/fs.h>
 #include <linux/module.h>
@@ -820,6 +821,37 @@ void drm_dev_put(struct drm_device *dev)
 }
 EXPORT_SYMBOL(drm_dev_put);
 
+static void drmm_cg_unregister_region(struct drm_device *dev, void *arg)
+{
+	dmem_cgroup_unregister_region(arg);
+}
+
+/**
+ * drmm_cgroup_register_region - Register a region of a DRM device to cgroups
+ * @dev: device for region
+ * @region_name: Region name for registering
+ * @size: Size of region in bytes
+ *
+ * This decreases the ref-count of @dev by one. The device is destroyed if the
+ * ref-count drops to zero.
+ */
+struct dmem_cgroup_region *drmm_cgroup_register_region(struct drm_device *dev, const char *region_name, u64 size)
+{
+	struct dmem_cgroup_region *region;
+	int ret;
+
+	region = dmem_cgroup_register_region(size, "drm/%s/%s", dev->unique, region_name);
+	if (IS_ERR_OR_NULL(region))
+		return region;
+
+	ret = drmm_add_action_or_reset(dev, drmm_cg_unregister_region, region);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return region;
+}
+EXPORT_SYMBOL_GPL(drmm_cgroup_register_region);
+
 static int create_compat_control_link(struct drm_device *dev)
 {
 	struct drm_minor *minor;