[PATCH v7 09/12] 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 which is
expected to be merged soon:
Link: https://patchwork.freedesktop.org/series/115802/

V5: Fix the db object reference leak (Christian)
V6: Pin the doorbell bo in userqueue_create() function, and unpin it
    in userqueue destoy (Christian)
V7: Added missing kfree for queue in error cases
    Added Alex's R-B

Cc: Alex Deucher <alexander.deucher at amd.com>
Cc: Christian Koenig <christian.koenig at amd.com>
Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
Signed-off-by: Shashank Sharma <shashank.sharma at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c | 58 +++++++++++++++++++
 drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c        |  1 +
 .../gpu/drm/amd/include/amdgpu_userqueue.h    |  1 +
 3 files changed, 60 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
index 141808e9296b..ec49c10f7511 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
@@ -94,6 +94,52 @@ void amdgpu_userqueue_destroy_object(struct amdgpu_userq_mgr *uq_mgr,
 	amdgpu_bo_unref(&userq_obj->obj);
 }
 
+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)
+{
+	uint64_t index;
+	struct drm_gem_object *gobj;
+	struct amdgpu_userq_obj *db_obj = &queue->db_obj;
+	int r;
+
+	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_obj->obj = amdgpu_bo_ref(gem_to_amdgpu_bo(gobj));
+	drm_gem_object_put(gobj);
+
+	/* Pin the BO before generating the index, unpin in queue destroy */
+	r = amdgpu_bo_pin(db_obj->obj, AMDGPU_GEM_DOMAIN_DOORBELL);
+	if (r) {
+		DRM_ERROR("[Usermode queues] Failed to pin doorbell object\n");
+		goto unref_bo;
+	}
+
+	r = amdgpu_bo_reserve(db_obj->obj, true);
+	if (r) {
+		DRM_ERROR("[Usermode queues] Failed to pin doorbell object\n");
+		goto unpin_bo;
+	}
+
+	index = amdgpu_doorbell_index_on_bar(uq_mgr->adev, db_obj->obj, doorbell_offset);
+	DRM_DEBUG_DRIVER("[Usermode queues] doorbell index=%lld\n", index);
+	amdgpu_bo_unreserve(db_obj->obj);
+	return index;
+
+unpin_bo:
+	amdgpu_bo_unpin(db_obj->obj);
+
+unref_bo:
+	amdgpu_bo_unref(&db_obj->obj);
+	return r;
+}
+
 static int
 amdgpu_userqueue_destroy(struct drm_file *filp, int queue_id)
 {
@@ -114,6 +160,8 @@ amdgpu_userqueue_destroy(struct drm_file *filp, int queue_id)
 
 	uq_funcs = adev->userq_funcs[queue->queue_type];
 	uq_funcs->mqd_destroy(uq_mgr, queue);
+	amdgpu_bo_unpin(queue->db_obj.obj);
+	amdgpu_bo_unref(&queue->db_obj.obj);
 	idr_remove(&uq_mgr->userq_idr, queue_id);
 	kfree(queue);
 
@@ -129,6 +177,7 @@ amdgpu_userqueue_create(struct drm_file *filp, union drm_amdgpu_userq *args)
 	struct amdgpu_device *adev = uq_mgr->adev;
 	const struct amdgpu_userq_funcs *uq_funcs;
 	struct amdgpu_usermode_queue *queue;
+	uint64_t index;
 	int qid, r = 0;
 
 	/* Usermode queues are only supported for GFX/SDMA engines as of now */
@@ -158,6 +207,15 @@ 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");
+		kfree(queue);
+		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 8c62a51025af..33de65a0d974 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
@@ -6605,6 +6605,7 @@ 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);
diff --git a/drivers/gpu/drm/amd/include/amdgpu_userqueue.h b/drivers/gpu/drm/amd/include/amdgpu_userqueue.h
index ffe8a3d73756..a653e31350c5 100644
--- a/drivers/gpu/drm/amd/include/amdgpu_userqueue.h
+++ b/drivers/gpu/drm/amd/include/amdgpu_userqueue.h
@@ -44,6 +44,7 @@ struct amdgpu_usermode_queue {
 	struct amdgpu_userq_mgr *userq_mgr;
 	struct amdgpu_vm	*vm;
 	struct amdgpu_userq_obj mqd;
+	struct amdgpu_userq_obj	db_obj;
 	struct amdgpu_userq_obj fw_obj;
 	struct amdgpu_userq_obj wptr_obj;
 };
-- 
2.42.0