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@xxxxxxxxxxxxxxxxxx>
> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> ---
> 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@xxxxxxxx>
> --
> 2.8.1
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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