This commit introduces a new helper amdgpu_lookup_queue_by_doorbell which helps look up a user queue with the given doorbell id in a xarray.
This function takes a kref of the user space queue. Signed-off-by: Zhu Lingshan <[email protected]> --- drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c | 30 +++++++++++++++++++++++ drivers/gpu/drm/amd/amdgpu/amdgpu_userq.h | 2 ++ 2 files changed, 32 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c index 0a816b3c5ff9..e0639f844a8e 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c @@ -609,6 +609,36 @@ struct amdgpu_usermode_queue *amdgpu_userq_get(struct amdgpu_userq_mgr *uq_mgr, return queue; } +/** + * amdgpu_lookup_queue_by_doorbell - look up a user queue by doorbell + * @xa: user queue XArray indexed by doorbell + * @doorbell: doorbell index + * + * Return: A queue with the doorbell indexed, or NULL if no such a queue found. + * + * This function increases kref of the queue, the caller + * must release the reference with amdgpu_userq_put(). + */ +struct amdgpu_usermode_queue * +amdgpu_lookup_queue_by_doorbell(struct xarray *xa, u32 doorbell) +{ + struct amdgpu_usermode_queue *queue; + unsigned long flags; + + xa_lock_irqsave(xa, flags); + queue = xa_load(xa, doorbell); + if (!queue) + goto out_unlock; + + if (!kref_get_unless_zero(&queue->refcount)) + queue = NULL; + +out_unlock: + xa_unlock_irqrestore(xa, flags); + + return queue; +} + void amdgpu_userq_put(struct amdgpu_usermode_queue *queue) { if (queue) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.h index 6412a7f7b6ef..8fc73862f64e 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.h @@ -151,6 +151,8 @@ struct amdgpu_db_info { }; struct amdgpu_usermode_queue *amdgpu_userq_get(struct amdgpu_userq_mgr *uq_mgr, u32 qid); +struct amdgpu_usermode_queue * +amdgpu_lookup_queue_by_doorbell(struct xarray *xa, u32 doorbell); void amdgpu_userq_put(struct amdgpu_usermode_queue *queue); int amdgpu_userq_ioctl(struct drm_device *dev, void *data, struct drm_file *filp); -- 2.53.0
