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: Chris Wilson chris@chris-wilson.co.uk Cc: Laurent Pinchart laurent.pinchart@ideasonboard.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com --- drivers/gpu/drm/drm_drv.c | 65 ++++++++++++++++++++++++++++++++--------------- include/drm/drm_drv.h | 13 ++++++++++ 2 files changed, 58 insertions(+), 20 deletions(-)
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index a8ce3179c07c..e122e4d022f8 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -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 driver->release() callback and control + * the finalization explicitly. * * RETURNS: * 0 on success, or error code on failure. @@ -553,6 +556,41 @@ 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 * @parent: Parent device object @@ -598,25 +636,12 @@ 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); - kfree(dev); + if (dev->driver->release) { + dev->driver->release(dev); + } else { + drm_dev_fini(dev); + kfree(dev); + } }
/** diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h index 732e85652d1e..5699f42195fe 100644 --- a/include/drm/drm_drv.h +++ b/include/drm/drm_drv.h @@ -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);
On Thu, Feb 02, 2017 at 09:36:32AM +0000, Chris Wilson wrote:
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: Chris Wilson chris@chris-wilson.co.uk Cc: Laurent Pinchart laurent.pinchart@ideasonboard.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com
drivers/gpu/drm/drm_drv.c | 65 ++++++++++++++++++++++++++++++++--------------- include/drm/drm_drv.h | 13 ++++++++++ 2 files changed, 58 insertions(+), 20 deletions(-)
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index a8ce3179c07c..e122e4d022f8 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -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 driver->release() callback and control
The new official way to reference a struct member is &foo.bar. I've applied this polish to both places and applied your patch, thanks a lot. -Daniel
- the finalization explicitly.
- RETURNS:
- 0 on success, or error code on failure.
@@ -553,6 +556,41 @@ 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
- @parent: Parent device object
@@ -598,25 +636,12 @@ 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);
- kfree(dev);
- if (dev->driver->release) {
dev->driver->release(dev);- } else {
drm_dev_fini(dev);kfree(dev);- }
}
/** diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h index 732e85652d1e..5699f42195fe 100644 --- a/include/drm/drm_drv.h +++ b/include/drm/drm_drv.h @@ -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); -- 2.11.0
dri-devel@lists.freedesktop.org
-
Chris Wilson -
Daniel Vetter