[01/11] drm: Export drm_dev_init() for subclassing
diff mbox

Message ID 1464357644-16775-2-git-send-email-chris@chris-wilson.co.uk
State New
Headers show

Commit Message

Chris Wilson May 27, 2016, 2 p.m. UTC
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.

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(-)

Comments

Nils Wallménius May 27, 2016, 3:29 p.m. UTC | #1
Hi, Chris

See comment below

BR
Nils
On 27 May 2016 7:01 a.m., "Chris Wilson" <chris@chris-wilson.co.uk> 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.
>
> 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..ceb85e611a07 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 0;

Shouldn't this return != 0?

> +}
> +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);
> --
> 2.8.1
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
Chris Wilson May 27, 2016, 3:36 p.m. UTC | #2
On Fri, May 27, 2016 at 05:29:43PM +0200, Nils Wallménius wrote:
>    Hi, Chris
> 
>    See comment below
> 
>    >  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 0;
> 
>    Shouldn't this return != 0?

You saw nothing, it always said return ret!
-Chris
Emil Velikov May 27, 2016, 3:54 p.m. UTC | #3
On 27 May 2016 at 16:36, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> On Fri, May 27, 2016 at 05:29:43PM +0200, Nils Wallménius wrote:
>>    Hi, Chris
>>
>>    See comment below
>>
>>    >  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 0;
>>
>>    Shouldn't this return != 0?
>
> You saw nothing, it always said return ret!
Chris can you please elaborate ? I believe Nils has a point here.

Afact the error path of _init should return != 0, plus you already
handle that case in _alloc, yet the function always returns 0.

Regards,
Emil
Chris Wilson May 27, 2016, 4:08 p.m. UTC | #4
On Fri, May 27, 2016 at 04:54:46PM +0100, Emil Velikov wrote:
> On 27 May 2016 at 16:36, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> > On Fri, May 27, 2016 at 05:29:43PM +0200, Nils Wallménius wrote:
> >>    Hi, Chris
> >>
> >>    See comment below
> >>
> >>    >  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 0;
> >>
> >>    Shouldn't this return != 0?
> >
> > You saw nothing, it always said return ret!
> Chris can you please elaborate ? I believe Nils has a point here.

I mean, "thanks for bringing that to my attention, oops it was meant to
say return ret ofc, fixed".
-Chris
Emil Velikov May 27, 2016, 4:11 p.m. UTC | #5
On 27 May 2016 at 17:08, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> On Fri, May 27, 2016 at 04:54:46PM +0100, Emil Velikov wrote:
>> On 27 May 2016 at 16:36, Chris Wilson <chris@chris-wilson.co.uk> wrote:
>> > On Fri, May 27, 2016 at 05:29:43PM +0200, Nils Wallménius wrote:
>> >>    Hi, Chris
>> >>
>> >>    See comment below
>> >>
>> >>    >  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 0;
>> >>
>> >>    Shouldn't this return != 0?
>> >
>> > You saw nothing, it always said return ret!
>> Chris can you please elaborate ? I believe Nils has a point here.
>
> I mean, "thanks for bringing that to my attention, oops it was meant to
> say return ret ofc, fixed".
Seems like I had a dull moment. Thanks for explaining !

-Emil

Patch
diff mbox

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index bff89226a344..ceb85e611a07 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 0;
+}
+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);