From 89cd9d23e9a74d94f0db5bbbaf2ef1f6ede36ae5 Mon Sep 17 00:00:00 2001 From: Philip Yang Date: Wed, 5 Dec 2018 14:03:43 -0500 Subject: [PATCH] drm/amdkfd: avoid HMM change cause circular lock MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit There is circular lock between gfx and kfd path with HMM change: lock(dqm) -> bo::reserve -> amdgpu_mn_lock To avoid this, move init/unint_mqd() out of lock(dqm), to remove nested locking between mmap_sem and bo::reserve. The locking order is: bo::reserve -> amdgpu_mn_lock(p->mn) Signed-off-by: Philip Yang Reviewed-by: Felix Kuehling Acked-by: Christian König Signed-off-by: Alex Deucher --- .../drm/amd/amdkfd/kfd_device_queue_manager.c | 32 ++++++++++--------- 1 file changed, 17 insertions(+), 15 deletions(-) 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 d6fe75245d05..cf6b57627842 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c @@ -1161,21 +1161,17 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q, int retval; struct mqd_manager *mqd_mgr; - retval = 0; - - dqm_lock(dqm); - 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_unlock; + goto out; } if (q->properties.type == KFD_QUEUE_TYPE_SDMA) { retval = allocate_sdma_queue(dqm, &q->sdma_id); if (retval) - goto out_unlock; + goto out; q->properties.sdma_queue_id = q->sdma_id / get_num_sdma_engines(dqm); q->properties.sdma_engine_id = @@ -1189,6 +1185,9 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q, if (retval) goto out_deallocate_sdma_queue; + /* Do init_mqd before dqm_lock(dqm) to avoid circular locking order: + * lock(dqm) -> bo::reserve + */ mqd_mgr = dqm->ops.get_mqd_manager(dqm, get_mqd_type_from_queue_type(q->properties.type)); @@ -1196,6 +1195,7 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q, retval = -ENOMEM; goto out_deallocate_doorbell; } + /* * Eviction state logic: we only mark active queues as evicted * to avoid the overhead of restoring inactive queues later @@ -1204,9 +1204,7 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q, q->properties.is_evicted = (q->properties.queue_size > 0 && q->properties.queue_percent > 0 && q->properties.queue_address != 0); - dqm->asic_ops.init_sdma_vm(dqm, q, qpd); - q->properties.tba_addr = qpd->tba_addr; q->properties.tma_addr = qpd->tma_addr; retval = mqd_mgr->init_mqd(mqd_mgr, &q->mqd, &q->mqd_mem_obj, @@ -1214,6 +1212,8 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q, if (retval) goto out_deallocate_doorbell; + dqm_lock(dqm); + list_add(&q->list, &qpd->queues_list); qpd->queue_count++; if (q->properties.is_active) { @@ -1241,9 +1241,7 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q, out_deallocate_sdma_queue: if (q->properties.type == KFD_QUEUE_TYPE_SDMA) deallocate_sdma_queue(dqm, q->sdma_id); -out_unlock: - dqm_unlock(dqm); - +out: return retval; } @@ -1406,8 +1404,6 @@ static int destroy_queue_cpsch(struct device_queue_manager *dqm, qpd->reset_wavefronts = true; } - mqd_mgr->uninit_mqd(mqd_mgr, q->mqd, q->mqd_mem_obj); - /* * Unconditionally decrement this counter, regardless of the queue's * type @@ -1418,6 +1414,9 @@ static int destroy_queue_cpsch(struct device_queue_manager *dqm, dqm_unlock(dqm); + /* Do uninit_mqd after dqm_unlock(dqm) to avoid circular locking */ + mqd_mgr->uninit_mqd(mqd_mgr, q->mqd, q->mqd_mem_obj); + return retval; failed: @@ -1641,7 +1640,11 @@ static int process_termination_cpsch(struct device_queue_manager *dqm, qpd->reset_wavefronts = false; } - /* lastly, free mqd resources */ + dqm_unlock(dqm); + + /* Lastly, free mqd resources. + * Do uninit_mqd() after dqm_unlock to avoid circular locking. + */ list_for_each_entry_safe(q, next, &qpd->queues_list, list) { mqd_mgr = dqm->ops.get_mqd_manager(dqm, get_mqd_type_from_queue_type(q->properties.type)); @@ -1655,7 +1658,6 @@ static int process_termination_cpsch(struct device_queue_manager *dqm, } out: - dqm_unlock(dqm); return retval; } -- 2.45.2