Commit f1b85962 authored by David Herrmann's avatar David Herrmann
Browse files

drm: make minor->index available early 



Instead of allocating the minor-index during registration, we now do this
during allocation. This way, debug-messages between minor-allocation and
minor-registration will now use the correct minor instead of 0. Same is
done for unregistration vs. free, so debug-messages between
device-shutdown and device-destruction show proper indices.

Even though minor-indices are allocated early, we don't enable minor
lookup early. Instead, we keep the entry set to NULL and replace it during
registration / unregistration. This way, the index is allocated but lookup
only works if registered.

Reviewed-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: default avatarDavid Herrmann <dh.herrmann@gmail.com>
parent ec8f112d

drivers/gpu/drm/drm_stub.c

+46 −38
Original line number Original line Diff line number Diff line
@@ -256,6 +256,8 @@ static struct drm_minor **drm_minor_get_slot(struct drm_device *dev, 
static int drm_minor_alloc(struct drm_device *dev, unsigned int type)

static int drm_minor_alloc(struct drm_device *dev, unsigned int type)

{

{

	struct drm_minor *minor;

	struct drm_minor *minor;

	unsigned long flags;

	int r;





	minor = kzalloc(sizeof(*minor), GFP_KERNEL);

	minor = kzalloc(sizeof(*minor), GFP_KERNEL);

	if (!minor)

	if (!minor)
@@ -264,57 +266,68 @@ static int drm_minor_alloc(struct drm_device *dev, unsigned int type) 
	minor->type = type;

	minor->type = type;

	minor->dev = dev;

	minor->dev = dev;





	idr_preload(GFP_KERNEL);

	spin_lock_irqsave(&drm_minor_lock, flags);

	r = idr_alloc(&drm_minors_idr,

		      NULL,

		      64 * type,

		      64 * (type + 1),

		      GFP_NOWAIT);

	spin_unlock_irqrestore(&drm_minor_lock, flags);

	idr_preload_end();



	if (r < 0)

		goto err_free;



	minor->index = r;



	*drm_minor_get_slot(dev, type) = minor;

	*drm_minor_get_slot(dev, type) = minor;

	return 0;

	return 0;



err_free:

	kfree(minor);

	return r;

}

}





static void drm_minor_free(struct drm_device *dev, unsigned int type)

static void drm_minor_free(struct drm_device *dev, unsigned int type)

{

{

	struct drm_minor **slot;

	struct drm_minor **slot, *minor;

	unsigned long flags;





	slot = drm_minor_get_slot(dev, type);

	slot = drm_minor_get_slot(dev, type);

	if (*slot) {

	minor = *slot;

		drm_mode_group_destroy(&(*slot)->mode_group);

	if (!minor)

		kfree(*slot);

		return;



	drm_mode_group_destroy(&minor->mode_group);



	spin_lock_irqsave(&drm_minor_lock, flags);

	idr_remove(&drm_minors_idr, minor->index);

	spin_unlock_irqrestore(&drm_minor_lock, flags);



	kfree(minor);

	*slot = NULL;

	*slot = NULL;

}

}

}





static int drm_minor_register(struct drm_device *dev, unsigned int type)

static int drm_minor_register(struct drm_device *dev, unsigned int type)

{

{

	struct drm_minor *new_minor;

	struct drm_minor *minor;

	unsigned long flags;

	unsigned long flags;

	int ret;

	int ret;

	int minor_id;





	DRM_DEBUG("\n");

	DRM_DEBUG("\n");





	new_minor = *drm_minor_get_slot(dev, type);

	minor = *drm_minor_get_slot(dev, type);

	if (!new_minor)

	if (!minor)

		return 0;

		return 0;





	idr_preload(GFP_KERNEL);

	ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);

	spin_lock_irqsave(&drm_minor_lock, flags);

	minor_id = idr_alloc(&drm_minors_idr,

			     NULL,

			     64 * type,

			     64 * (type + 1),

			     GFP_NOWAIT);

	spin_unlock_irqrestore(&drm_minor_lock, flags);

	idr_preload_end();



	if (minor_id < 0)

		return minor_id;



	new_minor->index = minor_id;



	ret = drm_debugfs_init(new_minor, minor_id, drm_debugfs_root);

	if (ret) {

	if (ret) {

		DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");

		DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");

		goto err_id;

		return ret;

	}

	}





	ret = drm_sysfs_device_add(new_minor);

	ret = drm_sysfs_device_add(minor);

	if (ret) {

	if (ret) {

		DRM_ERROR("DRM: Error sysfs_device_add.\n");

		DRM_ERROR("DRM: Error sysfs_device_add.\n");

		goto err_debugfs;

		goto err_debugfs;
@@ -322,19 +335,14 @@ static int drm_minor_register(struct drm_device *dev, unsigned int type) 




	/* replace NULL with @minor so lookups will succeed from now on */

	/* replace NULL with @minor so lookups will succeed from now on */

	spin_lock_irqsave(&drm_minor_lock, flags);

	spin_lock_irqsave(&drm_minor_lock, flags);

	idr_replace(&drm_minors_idr, new_minor, new_minor->index);

	idr_replace(&drm_minors_idr, minor, minor->index);

	spin_unlock_irqrestore(&drm_minor_lock, flags);

	spin_unlock_irqrestore(&drm_minor_lock, flags);





	DRM_DEBUG("new minor assigned %d\n", minor_id);

	DRM_DEBUG("new minor registered %d\n", minor->index);

	return 0;

	return 0;





err_debugfs:

err_debugfs:

	drm_debugfs_cleanup(new_minor);

	drm_debugfs_cleanup(minor);

err_id:

	spin_lock_irqsave(&drm_minor_lock, flags);

	idr_remove(&drm_minors_idr, minor_id);

	spin_unlock_irqrestore(&drm_minor_lock, flags);

	new_minor->index = 0;

	return ret;

	return ret;

}

}
@@ -347,10 +355,10 @@ static void drm_minor_unregister(struct drm_device *dev, unsigned int type) 
	if (!minor || !minor->kdev)

	if (!minor || !minor->kdev)

		return;

		return;





	/* replace @minor with NULL so lookups will fail from now on */

	spin_lock_irqsave(&drm_minor_lock, flags);

	spin_lock_irqsave(&drm_minor_lock, flags);

	idr_remove(&drm_minors_idr, minor->index);

	idr_replace(&drm_minors_idr, NULL, minor->index);

	spin_unlock_irqrestore(&drm_minor_lock, flags);

	spin_unlock_irqrestore(&drm_minor_lock, flags);

	minor->index = 0;





	drm_debugfs_cleanup(minor);

	drm_debugfs_cleanup(minor);

	drm_sysfs_device_remove(minor);

	drm_sysfs_device_remove(minor);

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