drm/amdkfd: Fix sdma queue allocate race condition

SDMA queue allocation requires the dqm lock at it modify
the global dqm members. Move up the dqm_lock so sdma
queue allocation is enclosed in the critical section. Move
mqd allocation out of critical section to avoid circular
lock dependency.

Signed-off-by: Oak Zeng <Oak.Zeng@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
index 3ac9e58b8328b2af92fcbf677ff6fb8f89b4b619..e5c6db1a2c1980db70cb884a440ebd849d2162a1 100644 (file)
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
@@ -1133,23 +1133,27 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
        if (dqm->total_queue_count >= max_num_of_queues_per_device) {
                pr_warn("Can't create new usermode queue because %d queues were already created\n",
                                dqm->total_queue_count);
-               retval = -EPERM;
-               goto out;
+               return -EPERM;
        }
 
+       mqd_mgr = dqm->mqd_mgrs[get_mqd_type_from_queue_type(
+                       q->properties.type)];
+       q->mqd_mem_obj = mqd_mgr->allocate_mqd(mqd_mgr->dev, &q->properties);
+       if (!q->mqd_mem_obj)
+               return -ENOMEM;
+
+       dqm_lock(dqm);
        if (q->properties.type == KFD_QUEUE_TYPE_SDMA ||
                q->properties.type == KFD_QUEUE_TYPE_SDMA_XGMI) {
                retval = allocate_sdma_queue(dqm, q);
                if (retval)
-                       goto out;
+                       goto out_unlock;
        }
 
        retval = allocate_doorbell(qpd, q);
        if (retval)
                goto out_deallocate_sdma_queue;
 
-       mqd_mgr = dqm->mqd_mgrs[get_mqd_type_from_queue_type(
-                       q->properties.type)];
        /*
         * Eviction state logic: mark all queues as evicted, even ones
         * not currently active. Restoring inactive queues later only
@@ -1161,14 +1165,8 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
                dqm->asic_ops.init_sdma_vm(dqm, q, qpd);
        q->properties.tba_addr = qpd->tba_addr;
        q->properties.tma_addr = qpd->tma_addr;
-       q->mqd_mem_obj = mqd_mgr->allocate_mqd(mqd_mgr->dev, &q->properties);
-       if (!q->mqd_mem_obj) {
-               retval = -ENOMEM;
-               goto out_deallocate_doorbell;
-       }
        mqd_mgr->init_mqd(mqd_mgr, &q->mqd, q->mqd_mem_obj,
                                &q->gart_mqd_addr, &q->properties);
-       dqm_lock(dqm);
 
        list_add(&q->list, &qpd->queues_list);
        qpd->queue_count++;
@@ -1194,13 +1192,13 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
        dqm_unlock(dqm);
        return retval;
 
-out_deallocate_doorbell:
-       deallocate_doorbell(qpd, q);
 out_deallocate_sdma_queue:
        if (q->properties.type == KFD_QUEUE_TYPE_SDMA ||
                q->properties.type == KFD_QUEUE_TYPE_SDMA_XGMI)
                deallocate_sdma_queue(dqm, q);
-out:
+out_unlock:
+       dqm_unlock(dqm);
+       mqd_mgr->free_mqd(mqd_mgr, q->mqd, q->mqd_mem_obj);
        return retval;
 }