[PATCH v5 08/10] drm/amdgpu: generate doorbell index for userqueue

[Shashank Sharma]

The userspace sends us the doorbell object and the relative doobell
index in the object to be used for the usermode queue, but the FW
expects the absolute doorbell index on the PCI BAR in the MQD. This
patch adds a function to convert this relative doorbell index to
absolute doorbell index.

This patch is dependent on the doorbell manager series:
Link: https://patchwork.freedesktop.org/series/115802/

V5: Fix the db object reference leak (Christian)

Cc: Alex Deucher <alexander.deucher at amd.com>
Cc: Christian Koenig <christian.koenig at amd.com>
Signed-off-by: Shashank Sharma <shashank.sharma at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c | 34 +++++++++++++++++++
 drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c        |  1 +
 2 files changed, 35 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
index bb774144c372..61064266c4f8 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
@@ -32,6 +32,31 @@ amdgpu_userqueue_find(struct amdgpu_userq_mgr *uq_mgr, int qid)
 	return idr_find(&uq_mgr->userq_idr, qid);
 }
 
+static uint64_t
+amdgpu_userqueue_get_doorbell_index(struct amdgpu_userq_mgr *uq_mgr,
+				     struct amdgpu_usermode_queue *queue,
+				     struct drm_file *filp,
+				     uint32_t doorbell_offset)
+{
+	struct drm_gem_object *gobj;
+	struct amdgpu_bo *db_bo;
+	uint64_t index;
+
+	gobj = drm_gem_object_lookup(filp, queue->doorbell_handle);
+	if (gobj == NULL) {
+		DRM_ERROR("Can't find GEM object for doorbell\n");
+		return -EINVAL;
+	}
+
+	db_bo = amdgpu_bo_ref(gem_to_amdgpu_bo(gobj));
+	drm_gem_object_put(gobj);
+
+	index = amdgpu_doorbell_index_on_bar(uq_mgr->adev, db_bo, doorbell_offset);
+	amdgpu_bo_unref(&db_bo);
+	DRM_DEBUG_DRIVER("[Usermode queues] doorbell index=%lld\n", index);
+	return index;
+}
+
 static int
 amdgpu_userqueue_destroy(struct drm_file *filp, int queue_id)
 {
@@ -64,6 +89,7 @@ amdgpu_userqueue_create(struct drm_file *filp, union drm_amdgpu_userq *args)
 	struct amdgpu_userq_mgr *uq_mgr = &fpriv->userq_mgr;
 	const struct amdgpu_userq_funcs *uq_funcs;
 	struct amdgpu_usermode_queue *queue;
+	uint64_t index;
 	int qid, r = 0;
 
 	mutex_lock(&uq_mgr->userq_mutex);
@@ -87,6 +113,14 @@ amdgpu_userqueue_create(struct drm_file *filp, union drm_amdgpu_userq *args)
 	queue->flags = args->in.flags;
 	queue->vm = &fpriv->vm;
 
+	/* Convert relative doorbell offset into absolute doorbell index */
+	index = amdgpu_userqueue_get_doorbell_index(uq_mgr, queue, filp, args->in.doorbell_offset);
+	if (index == (uint64_t)-EINVAL) {
+		DRM_ERROR("Failed to get doorbell for queue\n");
+		goto unlock;
+	}
+	queue->doorbell_index = index;
+
 	r = uq_funcs->mqd_create(uq_mgr, &args->in, queue);
 	if (r) {
 		DRM_ERROR("Failed to create Queue\n");
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
index afaeecb9940a..8edb020683a1 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
@@ -6719,6 +6719,7 @@ static int gfx_v11_0_userq_mqd_create(struct amdgpu_userq_mgr *uq_mgr,
 	userq_props.queue_size = mqd_user.queue_size;
 	userq_props.hqd_base_gpu_addr = mqd_user.queue_va;
 	userq_props.mqd_gpu_addr = queue->mqd.gpu_addr;
+	userq_props.doorbell_index = queue->doorbell_index;
 	userq_props.use_doorbell = true;
 
 	r = mqd_gfx_generic->init_mqd(adev, (void *)queue->mqd.cpu_ptr, &userq_props);
-- 
2.40.1