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Commit 6bcacf51 authored by Daniel Stone's avatar Daniel Stone Committed by Daniel Vetter
Browse files

drm: Add reference counting to blob properties 



Reference-count drm_property_blob objects, changing the API to
ref/unref.

Signed-off-by: default avatarDaniel Stone <daniels@collabora.com>
Reviewed-by: default avatarMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
[danvet: Squash in kerneldoc fixup from Daniel Stone.]
[danvet: Squash in Oops fix from Thiery Reding.]
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent 8fb6e7a5

drivers/gpu/drm/drm_crtc.c

+149 −14
Original line number Diff line number Diff line
@@ -352,7 +352,9 @@ static struct drm_mode_object *_object_find(struct drm_device *dev, 
	if (obj && obj->id != id)

		obj = NULL;

	/* don't leak out unref'd fb's */

	if (obj && (obj->type == DRM_MODE_OBJECT_FB))

	if (obj &&

	    (obj->type == DRM_MODE_OBJECT_FB ||

	     obj->type == DRM_MODE_OBJECT_BLOB))

		obj = NULL;

	mutex_unlock(&dev->mode_config.idr_mutex);
@@ -377,7 +379,7 @@ struct drm_mode_object *drm_mode_object_find(struct drm_device *dev, 


	/* Framebuffers are reference counted and need their own lookup

	 * function.*/

	WARN_ON(type == DRM_MODE_OBJECT_FB);

	WARN_ON(type == DRM_MODE_OBJECT_FB || type == DRM_MODE_OBJECT_BLOB);

	obj = _object_find(dev, id, type);

	return obj;

}
@@ -4202,7 +4204,7 @@ int drm_mode_getproperty_ioctl(struct drm_device *dev, 
	return ret;

}



static struct drm_property_blob *

struct drm_property_blob *

drm_property_create_blob(struct drm_device *dev, size_t length,

			 const void *data)

{
@@ -4217,6 +4219,7 @@ drm_property_create_blob(struct drm_device *dev, size_t length, 
		return NULL;



	blob->length = length;

	blob->dev = dev;



	memcpy(blob->data, data, length);
@@ -4229,24 +4232,146 @@ drm_property_create_blob(struct drm_device *dev, size_t length, 
		return NULL;

	}



	kref_init(&blob->refcount);



	list_add_tail(&blob->head, &dev->mode_config.property_blob_list);



	mutex_unlock(&dev->mode_config.blob_lock);



	return blob;

}

EXPORT_SYMBOL(drm_property_create_blob);



static void drm_property_destroy_blob(struct drm_device *dev,

			       struct drm_property_blob *blob)

/**

 * drm_property_free_blob - Blob property destructor

 *

 * Internal free function for blob properties; must not be used directly.

 *

 * @param kref Reference

 */

static void drm_property_free_blob(struct kref *kref)

{

	mutex_lock(&dev->mode_config.blob_lock);

	drm_mode_object_put(dev, &blob->base);

	struct drm_property_blob *blob =

		container_of(kref, struct drm_property_blob, refcount);



	WARN_ON(!mutex_is_locked(&blob->dev->mode_config.blob_lock));



	list_del(&blob->head);

	mutex_unlock(&dev->mode_config.blob_lock);

	drm_mode_object_put(blob->dev, &blob->base);



	kfree(blob);

}



/**

 * drm_property_unreference_blob - Unreference a blob property

 *

 * Drop a reference on a blob property. May free the object.

 *

 * @param blob Pointer to blob property

 */

void drm_property_unreference_blob(struct drm_property_blob *blob)

{

	struct drm_device *dev;



	if (!blob)

		return;



	dev = blob->dev;



	DRM_DEBUG("%p: blob ID: %d (%d)\n", blob, blob->base.id, atomic_read(&blob->refcount.refcount));



	if (kref_put_mutex(&blob->refcount, drm_property_free_blob,

			   &dev->mode_config.blob_lock))

		mutex_unlock(&dev->mode_config.blob_lock);

	else

		might_lock(&dev->mode_config.blob_lock);



}

EXPORT_SYMBOL(drm_property_unreference_blob);



/**

 * drm_property_unreference_blob_locked - Unreference a blob property with blob_lock held

 *

 * Drop a reference on a blob property. May free the object. This must be

 * called with blob_lock held.

 *

 * @param dev  Device the blob was created on

 * @param blob Pointer to blob property

 */

static void drm_property_unreference_blob_locked(struct drm_property_blob *blob)

{

	if (!blob)

		return;



	DRM_DEBUG("%p: blob ID: %d (%d)\n", blob, blob->base.id, atomic_read(&blob->refcount.refcount));



	kref_put(&blob->refcount, drm_property_free_blob);

}



/**

 * drm_property_reference_blob - Take a reference on an existing property

 *

 * Take a new reference on an existing blob property.

 *

 * @param blob Pointer to blob property

 */

struct drm_property_blob *drm_property_reference_blob(struct drm_property_blob *blob)

{

	DRM_DEBUG("%p: blob ID: %d (%d)\n", blob, blob->base.id, atomic_read(&blob->refcount.refcount));

	kref_get(&blob->refcount);

	return blob;

}

EXPORT_SYMBOL(drm_property_reference_blob);



/*

 * Like drm_property_lookup_blob, but does not return an additional reference.

 * Must be called with blob_lock held.

 */

static struct drm_property_blob *__drm_property_lookup_blob(struct drm_device *dev,

							    uint32_t id)

{

	struct drm_mode_object *obj = NULL;

	struct drm_property_blob *blob;



	WARN_ON(!mutex_is_locked(&dev->mode_config.blob_lock));



	mutex_lock(&dev->mode_config.idr_mutex);

	obj = idr_find(&dev->mode_config.crtc_idr, id);

	if (!obj || (obj->type != DRM_MODE_OBJECT_BLOB) || (obj->id != id))

		blob = NULL;

	else

		blob = obj_to_blob(obj);

	mutex_unlock(&dev->mode_config.idr_mutex);



	return blob;

}



/**

 * drm_property_lookup_blob - look up a blob property and take a reference

 * @dev: drm device

 * @id: id of the blob property

 *

 * If successful, this takes an additional reference to the blob property.

 * callers need to make sure to eventually unreference the returned property

 * again, using @drm_property_unreference_blob.

 */

struct drm_property_blob *drm_property_lookup_blob(struct drm_device *dev,

					           uint32_t id)

{

	struct drm_property_blob *blob;



	mutex_lock(&dev->mode_config.blob_lock);

	blob = __drm_property_lookup_blob(dev, id);

	if (blob) {

		if (!kref_get_unless_zero(&blob->refcount))

			blob = NULL;

	}

	mutex_unlock(&dev->mode_config.blob_lock);



	return blob;

}

EXPORT_SYMBOL(drm_property_lookup_blob);



/**

 * drm_property_replace_global_blob - atomically replace existing blob property

 * @dev: drm device
@@ -4313,14 +4438,14 @@ static int drm_property_replace_global_blob(struct drm_device *dev, 
	}



	if (old_blob)

		drm_property_destroy_blob(dev, old_blob);

		drm_property_unreference_blob(old_blob);



	*replace = new_blob;



	return 0;



err_created:

	drm_property_destroy_blob(dev, new_blob);

	drm_property_unreference_blob(new_blob);

	return ret;

}
@@ -4351,7 +4476,7 @@ int drm_mode_getblob_ioctl(struct drm_device *dev, 


	drm_modeset_lock_all(dev);

	mutex_lock(&dev->mode_config.blob_lock);

	blob = drm_property_blob_find(dev, out_resp->blob_id);

	blob = __drm_property_lookup_blob(dev, out_resp->blob_id);

	if (!blob) {

		ret = -ENOENT;

		goto done;
@@ -4515,8 +4640,18 @@ bool drm_property_change_valid_get(struct drm_property *property, 
			valid_mask |= (1ULL << property->values[i]);

		return !(value & ~valid_mask);

	} else if (drm_property_type_is(property, DRM_MODE_PROP_BLOB)) {

		/* Only the driver knows */

		struct drm_property_blob *blob;



		if (value == 0)

			return true;



		blob = drm_property_lookup_blob(property->dev, value);

		if (blob) {

			*ref = &blob->base;

			return true;

		} else {

			return false;

		}

	} else if (drm_property_type_is(property, DRM_MODE_PROP_OBJECT)) {

		/* a zero value for an object property translates to null: */

		if (value == 0)
@@ -5566,7 +5701,7 @@ void drm_mode_config_cleanup(struct drm_device *dev) 


	list_for_each_entry_safe(blob, bt, &dev->mode_config.property_blob_list,

				 head) {

		drm_property_destroy_blob(dev, blob);

		drm_property_unreference_blob(blob);

	}



	/*

include/drm/drm_crtc.h

+9 −8
Original line number Diff line number Diff line
@@ -216,6 +216,8 @@ struct drm_framebuffer { 


struct drm_property_blob {

	struct drm_mode_object base;

	struct drm_device *dev;

	struct kref refcount;

	struct list_head head;

	size_t length;

	unsigned char data[];
@@ -1365,6 +1367,13 @@ struct drm_property *drm_property_create_object(struct drm_device *dev, 
					 int flags, const char *name, uint32_t type);

struct drm_property *drm_property_create_bool(struct drm_device *dev, int flags,

					 const char *name);

struct drm_property_blob *drm_property_create_blob(struct drm_device *dev,

                                                   size_t length,

                                                   const void *data);

struct drm_property_blob *drm_property_lookup_blob(struct drm_device *dev,

                                                   uint32_t id);

struct drm_property_blob *drm_property_reference_blob(struct drm_property_blob *blob);

void drm_property_unreference_blob(struct drm_property_blob *blob);

extern void drm_property_destroy(struct drm_device *dev, struct drm_property *property);

extern int drm_property_add_enum(struct drm_property *property, int index,

				 uint64_t value, const char *name);
@@ -1528,14 +1537,6 @@ static inline struct drm_property *drm_property_find(struct drm_device *dev, 
	return mo ? obj_to_property(mo) : NULL;

}



static inline struct drm_property_blob *

drm_property_blob_find(struct drm_device *dev, uint32_t id)

{

	struct drm_mode_object *mo;

	mo = drm_mode_object_find(dev, id, DRM_MODE_OBJECT_BLOB);

	return mo ? obj_to_blob(mo) : NULL;

}



/* Plane list iterator for legacy (overlay only) planes. */

#define drm_for_each_legacy_plane(plane, planelist) \

	list_for_each_entry(plane, planelist, head) \