| Message ID | 20170202093632.31017-1-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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 >
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);