Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f30c9257 authored by Chris Wilson's avatar Chris Wilson Committed by Daniel Vetter
Browse files

drm: Provide a driver hook for drm_dev_release() 



Some state is coupled into the device lifetime outside of the
load/unload timeframe and requires teardown during final unreference
from drm_dev_release(). For example, dmabufs hold both a device and
module reference and may live longer than expected (i.e. the current
pattern of the driver tearing down its state and then releasing a
reference to the drm device) and yet touch driver private state when
destroyed.

v2: Export drm_dev_fini() and move the responsibility for finalizing the
drm_device and freeing it to the release callback. (If no callback is
provided, the core will call drm_dev_fini() and kfree(dev) as before.)
v3: Remember to add drm_dev_fini() to drm_drv.h
v4: Tidy language for kerneldoc
v5: Cross reference from drm_dev_init() to note that driver->release()
allows for arbitrary embedding.
v6: Refer to driver data rather than driver state, as state is now
becoming associated with the struct drm_atomic_state and friends.

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
[danvet: Use the proper reference for struct members, which is
&drm_driver.release.]
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170202093632.31017-1-chris@chris-wilson.co.uk
parent 8aaacbc0

drivers/gpu/drm/drm_drv.c

+45 −20
Original line number Diff line number Diff line
@@ -465,7 +465,10 @@ static void drm_fs_inode_free(struct inode *inode) 
 * that do embed &struct drm_device it must be placed first in the overall

 * structure, and the overall structure must be allocated using kmalloc(): The

 * drm core's release function unconditionally calls kfree() on the @dev pointer

 * when the final reference is released.

 * when the final reference is released. To override this behaviour, and so

 * allow embedding of the drm_device inside the driver's device struct at an

 * arbitrary offset, you must supply a &drm_driver.release callback and control

 * the finalization explicitly.

 *

 * RETURNS:

 * 0 on success, or error code on failure.
@@ -552,6 +555,41 @@ int drm_dev_init(struct drm_device *dev, 
}

EXPORT_SYMBOL(drm_dev_init);



/**

 * drm_dev_fini - Finalize a dead DRM device

 * @dev: DRM device

 *

 * Finalize a dead DRM device. This is the converse to drm_dev_init() and

 * frees up all data allocated by it. All driver private data should be

 * finalized first. Note that this function does not free the @dev, that is

 * left to the caller.

 *

 * The ref-count of @dev must be zero, and drm_dev_fini() should only be called

 * from a &drm_driver.release callback.

 */

void drm_dev_fini(struct drm_device *dev)

{

	drm_vblank_cleanup(dev);



	if (drm_core_check_feature(dev, DRIVER_GEM))

		drm_gem_destroy(dev);



	drm_legacy_ctxbitmap_cleanup(dev);

	drm_ht_remove(&dev->map_hash);

	drm_fs_inode_free(dev->anon_inode);



	drm_minor_free(dev, DRM_MINOR_PRIMARY);

	drm_minor_free(dev, DRM_MINOR_RENDER);

	drm_minor_free(dev, DRM_MINOR_CONTROL);



	mutex_destroy(&dev->master_mutex);

	mutex_destroy(&dev->ctxlist_mutex);

	mutex_destroy(&dev->filelist_mutex);

	mutex_destroy(&dev->struct_mutex);

	kfree(dev->unique);

}

EXPORT_SYMBOL(drm_dev_fini);



/**

 * drm_dev_alloc - Allocate new DRM device

 * @driver: DRM driver to allocate device for
@@ -598,26 +636,13 @@ static void drm_dev_release(struct kref *ref) 
{

	struct drm_device *dev = container_of(ref, struct drm_device, ref);



	drm_vblank_cleanup(dev);



	if (drm_core_check_feature(dev, DRIVER_GEM))

		drm_gem_destroy(dev);



	drm_legacy_ctxbitmap_cleanup(dev);

	drm_ht_remove(&dev->map_hash);

	drm_fs_inode_free(dev->anon_inode);



	drm_minor_free(dev, DRM_MINOR_PRIMARY);

	drm_minor_free(dev, DRM_MINOR_RENDER);

	drm_minor_free(dev, DRM_MINOR_CONTROL);



	mutex_destroy(&dev->master_mutex);

	mutex_destroy(&dev->ctxlist_mutex);

	mutex_destroy(&dev->filelist_mutex);

	mutex_destroy(&dev->struct_mutex);

	kfree(dev->unique);

	if (dev->driver->release) {

		dev->driver->release(dev);

	} else {

		drm_dev_fini(dev);

		kfree(dev);

	}

}



/**

 * drm_dev_ref - Take reference of a DRM device

include/drm/drm_drv.h

+13 −0
Original line number Diff line number Diff line
@@ -102,6 +102,17 @@ struct drm_driver { 
	 *

	 */

	void (*unload) (struct drm_device *);



	/**

	 * @release:

	 *

	 * Optional callback for destroying device data after the final

	 * reference is released, i.e. the device is being destroyed. Drivers

	 * using this callback are responsible for calling drm_dev_fini()

	 * to finalize the device and then freeing the struct themselves.

	 */

	void (*release) (struct drm_device *);



	int (*set_busid)(struct drm_device *dev, struct drm_master *master);



	/**
@@ -437,6 +448,8 @@ extern unsigned int drm_debug; 
int drm_dev_init(struct drm_device *dev,

		 struct drm_driver *driver,

		 struct device *parent);

void drm_dev_fini(struct drm_device *dev);



struct drm_device *drm_dev_alloc(struct drm_driver *driver,

				 struct device *parent);

int drm_dev_register(struct drm_device *dev, unsigned long flags);