| Message ID | 1464597519-16659-2-git-send-email-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, May 30, 2016 at 09:38:19AM +0100, Chris Wilson wrote: > In order to allow drivers to pack their privates and drm_device into one > struct (e.g. for subclassing), export the initialisation routines for > struct drm_device. > > v2: Missed return ret. That error path had only one job to do! > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > Cc: dri-devel@lists.freedesktop.org > --- > drivers/gpu/drm/drm_drv.c | 63 ++++++++++++++++++++++++++++++++++++----------- > include/drm/drmP.h | 3 +++ > 2 files changed, 52 insertions(+), 14 deletions(-) > > diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c > index bff89226a344..f0553ccd4f71 100644 > --- a/drivers/gpu/drm/drm_drv.c > +++ b/drivers/gpu/drm/drm_drv.c > @@ -549,11 +549,12 @@ static void drm_fs_inode_free(struct inode *inode) > } > > /** > - * drm_dev_alloc - Allocate new DRM device > - * @driver: DRM driver to allocate device for > + * drm_dev_init - Initialise new DRM device > + * @dev: DRM device > + * @driver: DRM driver > * @parent: Parent device object > * > - * Allocate and initialize a new DRM device. No device registration is done. > + * Initialize a new DRM device. No device registration is done. > * Call drm_dev_register() to advertice the device to user space and register it > * with other core subsystems. This should be done last in the device > * initialization sequence to make sure userspace can't access an inconsistent > @@ -565,18 +566,14 @@ static void drm_fs_inode_free(struct inode *inode) > * Note that for purely virtual devices @parent can be NULL. Maybe add "Drivers which don't want to allocate their own device structure embedding &drm_device can instead just call drm_dev_alloc()." > * > * RETURNS: > - * Pointer to new DRM device, or NULL if out of memory. > + * 0 on success, or error code on failure. > */ > -struct drm_device *drm_dev_alloc(struct drm_driver *driver, > - struct device *parent) > +int drm_dev_init(struct drm_device *dev, > + struct drm_driver *driver, > + struct device *parent) > { > - struct drm_device *dev; > int ret; > > - dev = kzalloc(sizeof(*dev), GFP_KERNEL); > - if (!dev) > - return NULL; > - > kref_init(&dev->ref); > dev->dev = parent; > dev->driver = driver; > @@ -638,7 +635,7 @@ struct drm_device *drm_dev_alloc(struct drm_driver *driver, > goto err_setunique; > } > > - return dev; > + return 0; > > err_setunique: > if (drm_core_check_feature(dev, DRIVER_GEM)) > @@ -653,8 +650,46 @@ err_minors: > drm_fs_inode_free(dev->anon_inode); > err_free: > mutex_destroy(&dev->master_mutex); > - kfree(dev); > - return NULL; > + return ret; for "goto err_minors" you need to set ret first, otherwise we'll fail and return 0. Wasn't a problem because of the unconditional return NULL here. > +} > +EXPORT_SYMBOL(drm_dev_init); > + > +/** > + * drm_dev_alloc - Allocate new DRM device > + * @driver: DRM driver to allocate device for > + * @parent: Parent device object > + * > + * Allocate and initialize a new DRM device. No device registration is done. > + * Call drm_dev_register() to advertice the device to user space and register it > + * with other core subsystems. This should be done last in the device > + * initialization sequence to make sure userspace can't access an inconsistent > + * state. > + * > + * The initial ref-count of the object is 1. Use drm_dev_ref() and > + * drm_dev_unref() to take and drop further ref-counts. > + * > + * Note that for purely virtual devices @parent can be NULL. Maybe we can also add "Drivers which want to subclass/embed struct &drm_device should instead look at drm_dev_init()." > + * > + * RETURNS: > + * Pointer to new DRM device, or NULL if out of memory. > + */ > +struct drm_device *drm_dev_alloc(struct drm_driver *driver, > + struct device *parent) > +{ > + struct drm_device *dev; > + int ret; > + > + dev = kzalloc(sizeof(*dev), GFP_KERNEL); > + if (!dev) > + return NULL; > + > + ret = drm_dev_init(dev, driver, parent); > + if (ret) { > + kfree(dev); > + return NULL; > + } > + > + return dev; > } > EXPORT_SYMBOL(drm_dev_alloc); > > diff --git a/include/drm/drmP.h b/include/drm/drmP.h > index c5d29505f937..12dc5f9cad89 100644 > --- a/include/drm/drmP.h > +++ b/include/drm/drmP.h > @@ -1075,6 +1075,9 @@ extern void drm_sysfs_hotplug_event(struct drm_device *dev); > > struct drm_device *drm_dev_alloc(struct drm_driver *driver, > struct device *parent); > +int drm_dev_init(struct drm_device *dev, > + struct drm_driver *driver, > + struct device *parent); > void drm_dev_ref(struct drm_device *dev); > void drm_dev_unref(struct drm_device *dev); > int drm_dev_register(struct drm_device *dev, unsigned long flags); With the one bug in the error handling fixed, and the kerneldoc augmented: Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> > -- > 2.8.1 >
On Wed, Jun 01, 2016 at 12:01:44PM +0200, Daniel Vetter wrote: > On Mon, May 30, 2016 at 09:38:19AM +0100, Chris Wilson wrote: > > In order to allow drivers to pack their privates and drm_device into one > > struct (e.g. for subclassing), export the initialisation routines for > > struct drm_device. > > > > v2: Missed return ret. That error path had only one job to do! > > > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > > Cc: dri-devel@lists.freedesktop.org > > --- > > drivers/gpu/drm/drm_drv.c | 63 ++++++++++++++++++++++++++++++++++++----------- > > include/drm/drmP.h | 3 +++ > > 2 files changed, 52 insertions(+), 14 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c > > index bff89226a344..f0553ccd4f71 100644 > > --- a/drivers/gpu/drm/drm_drv.c > > +++ b/drivers/gpu/drm/drm_drv.c > > @@ -549,11 +549,12 @@ static void drm_fs_inode_free(struct inode *inode) > > } > > > > /** > > - * drm_dev_alloc - Allocate new DRM device > > - * @driver: DRM driver to allocate device for > > + * drm_dev_init - Initialise new DRM device > > + * @dev: DRM device > > + * @driver: DRM driver > > * @parent: Parent device object > > * > > - * Allocate and initialize a new DRM device. No device registration is done. > > + * Initialize a new DRM device. No device registration is done. > > * Call drm_dev_register() to advertice the device to user space and register it > > * with other core subsystems. This should be done last in the device > > * initialization sequence to make sure userspace can't access an inconsistent > > @@ -565,18 +566,14 @@ static void drm_fs_inode_free(struct inode *inode) > > * Note that for purely virtual devices @parent can be NULL. > > Maybe add "Drivers which don't want to allocate their own device structure > embedding &drm_device can instead just call drm_dev_alloc()." > > * > > * RETURNS: > > - * Pointer to new DRM device, or NULL if out of memory. > > + * 0 on success, or error code on failure. > > */ > > -struct drm_device *drm_dev_alloc(struct drm_driver *driver, > > - struct device *parent) > > +int drm_dev_init(struct drm_device *dev, > > + struct drm_driver *driver, > > + struct device *parent) > > { > > - struct drm_device *dev; > > int ret; > > > > - dev = kzalloc(sizeof(*dev), GFP_KERNEL); > > - if (!dev) > > - return NULL; > > - > > kref_init(&dev->ref); > > dev->dev = parent; > > dev->driver = driver; > > @@ -638,7 +635,7 @@ struct drm_device *drm_dev_alloc(struct drm_driver *driver, > > goto err_setunique; > > } > > > > - return dev; > > + return 0; > > > > err_setunique: > > if (drm_core_check_feature(dev, DRIVER_GEM)) > > @@ -653,8 +650,46 @@ err_minors: > > drm_fs_inode_free(dev->anon_inode); > > err_free: > > mutex_destroy(&dev->master_mutex); > > - kfree(dev); > > - return NULL; > > + return ret; > > for "goto err_minors" you need to set ret first, otherwise we'll fail and > return 0. Wasn't a problem because of the unconditional return NULL here. > > > +} > > +EXPORT_SYMBOL(drm_dev_init); > > + > > +/** > > + * drm_dev_alloc - Allocate new DRM device > > + * @driver: DRM driver to allocate device for > > + * @parent: Parent device object > > + * > > + * Allocate and initialize a new DRM device. No device registration is done. > > + * Call drm_dev_register() to advertice the device to user space and register it > > + * with other core subsystems. This should be done last in the device > > + * initialization sequence to make sure userspace can't access an inconsistent > > + * state. > > + * > > + * The initial ref-count of the object is 1. Use drm_dev_ref() and > > + * drm_dev_unref() to take and drop further ref-counts. > > + * > > + * Note that for purely virtual devices @parent can be NULL. > > Maybe we can also add "Drivers which want to subclass/embed struct > &drm_device should instead look at drm_dev_init()." > > > + * > > + * RETURNS: > > + * Pointer to new DRM device, or NULL if out of memory. > > + */ > > +struct drm_device *drm_dev_alloc(struct drm_driver *driver, > > + struct device *parent) > > +{ > > + struct drm_device *dev; > > + int ret; > > + > > + dev = kzalloc(sizeof(*dev), GFP_KERNEL); > > + if (!dev) > > + return NULL; > > + > > + ret = drm_dev_init(dev, driver, parent); > > + if (ret) { > > + kfree(dev); > > + return NULL; > > + } > > + > > + return dev; > > } > > EXPORT_SYMBOL(drm_dev_alloc); > > > > diff --git a/include/drm/drmP.h b/include/drm/drmP.h > > index c5d29505f937..12dc5f9cad89 100644 > > --- a/include/drm/drmP.h > > +++ b/include/drm/drmP.h > > @@ -1075,6 +1075,9 @@ extern void drm_sysfs_hotplug_event(struct drm_device *dev); > > > > struct drm_device *drm_dev_alloc(struct drm_driver *driver, > > struct device *parent); > > +int drm_dev_init(struct drm_device *dev, > > + struct drm_driver *driver, > > + struct device *parent); > > void drm_dev_ref(struct drm_device *dev); > > void drm_dev_unref(struct drm_device *dev); > > int drm_dev_register(struct drm_device *dev, unsigned long flags); > > With the one bug in the error handling fixed, and the kerneldoc augmented: > > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> r-b retracted, this is a bit incomplete since it doesn't handle drm_dev_release. I think we also should add an optional ->device_free callback and use that in drm_dev_release instead of kfree(). That would finally make the drm_device refcounting also somewhat useful, since right now you have to release driver-private stuff before the device is actually gone, which is buggy. Or just leak, which is also buggy ;-) -Daniel
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index bff89226a344..f0553ccd4f71 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -549,11 +549,12 @@ static void drm_fs_inode_free(struct inode *inode) } /** - * drm_dev_alloc - Allocate new DRM device - * @driver: DRM driver to allocate device for + * drm_dev_init - Initialise new DRM device + * @dev: DRM device + * @driver: DRM driver * @parent: Parent device object * - * Allocate and initialize a new DRM device. No device registration is done. + * Initialize a new DRM device. No device registration is done. * Call drm_dev_register() to advertice the device to user space and register it * with other core subsystems. This should be done last in the device * initialization sequence to make sure userspace can't access an inconsistent @@ -565,18 +566,14 @@ static void drm_fs_inode_free(struct inode *inode) * Note that for purely virtual devices @parent can be NULL. * * RETURNS: - * Pointer to new DRM device, or NULL if out of memory. + * 0 on success, or error code on failure. */ -struct drm_device *drm_dev_alloc(struct drm_driver *driver, - struct device *parent) +int drm_dev_init(struct drm_device *dev, + struct drm_driver *driver, + struct device *parent) { - struct drm_device *dev; int ret; - dev = kzalloc(sizeof(*dev), GFP_KERNEL); - if (!dev) - return NULL; - kref_init(&dev->ref); dev->dev = parent; dev->driver = driver; @@ -638,7 +635,7 @@ struct drm_device *drm_dev_alloc(struct drm_driver *driver, goto err_setunique; } - return dev; + return 0; err_setunique: if (drm_core_check_feature(dev, DRIVER_GEM)) @@ -653,8 +650,46 @@ err_minors: drm_fs_inode_free(dev->anon_inode); err_free: mutex_destroy(&dev->master_mutex); - kfree(dev); - return NULL; + return ret; +} +EXPORT_SYMBOL(drm_dev_init); + +/** + * drm_dev_alloc - Allocate new DRM device + * @driver: DRM driver to allocate device for + * @parent: Parent device object + * + * Allocate and initialize a new DRM device. No device registration is done. + * Call drm_dev_register() to advertice the device to user space and register it + * with other core subsystems. This should be done last in the device + * initialization sequence to make sure userspace can't access an inconsistent + * state. + * + * The initial ref-count of the object is 1. Use drm_dev_ref() and + * drm_dev_unref() to take and drop further ref-counts. + * + * Note that for purely virtual devices @parent can be NULL. + * + * RETURNS: + * Pointer to new DRM device, or NULL if out of memory. + */ +struct drm_device *drm_dev_alloc(struct drm_driver *driver, + struct device *parent) +{ + struct drm_device *dev; + int ret; + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) + return NULL; + + ret = drm_dev_init(dev, driver, parent); + if (ret) { + kfree(dev); + return NULL; + } + + return dev; } EXPORT_SYMBOL(drm_dev_alloc); diff --git a/include/drm/drmP.h b/include/drm/drmP.h index c5d29505f937..12dc5f9cad89 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -1075,6 +1075,9 @@ extern void drm_sysfs_hotplug_event(struct drm_device *dev); struct drm_device *drm_dev_alloc(struct drm_driver *driver, struct device *parent); +int drm_dev_init(struct drm_device *dev, + struct drm_driver *driver, + struct device *parent); void drm_dev_ref(struct drm_device *dev); void drm_dev_unref(struct drm_device *dev); int drm_dev_register(struct drm_device *dev, unsigned long flags);
In order to allow drivers to pack their privates and drm_device into one struct (e.g. for subclassing), export the initialisation routines for struct drm_device. v2: Missed return ret. That error path had only one job to do! Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: dri-devel@lists.freedesktop.org --- drivers/gpu/drm/drm_drv.c | 63 ++++++++++++++++++++++++++++++++++++----------- include/drm/drmP.h | 3 +++ 2 files changed, 52 insertions(+), 14 deletions(-)