diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c index b98c0969d3be..73288f9ccaf8 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c @@ -1384,7 +1384,6 @@ static int init_kfd_vm(struct amdgpu_vm *vm, void **process_info, amdgpu_amdkfd_restore_userptr_worker); *process_info = info; - *ef = dma_fence_get(&info->eviction_fence->base); } vm->process_info = *process_info; @@ -1415,6 +1414,8 @@ static int init_kfd_vm(struct amdgpu_vm *vm, void **process_info, list_add_tail(&vm->vm_list_node, &(vm->process_info->vm_list_head)); vm->process_info->n_vms++; + + *ef = dma_fence_get(&vm->process_info->eviction_fence->base); mutex_unlock(&vm->process_info->lock); return 0; @@ -1426,10 +1427,7 @@ validate_pd_fail: reserve_pd_fail: vm->process_info = NULL; if (info) { - /* Two fence references: one in info and one in *ef */ dma_fence_put(&info->eviction_fence->base); - dma_fence_put(*ef); - *ef = NULL; *process_info = NULL; put_pid(info->pid); create_evict_fence_fail: @@ -1623,7 +1621,8 @@ int amdgpu_amdkfd_criu_resume(void *p) goto out_unlock; } WRITE_ONCE(pinfo->block_mmu_notifications, false); - schedule_delayed_work(&pinfo->restore_userptr_work, 0); + queue_delayed_work(system_freezable_wq, + &pinfo->restore_userptr_work, 0); out_unlock: mutex_unlock(&pinfo->lock); @@ -2426,7 +2425,8 @@ int amdgpu_amdkfd_evict_userptr(struct mmu_interval_notifier *mni, KFD_QUEUE_EVICTION_TRIGGER_USERPTR); if (r) pr_err("Failed to quiesce KFD\n"); - schedule_delayed_work(&process_info->restore_userptr_work, + queue_delayed_work(system_freezable_wq, + &process_info->restore_userptr_work, msecs_to_jiffies(AMDGPU_USERPTR_RESTORE_DELAY_MS)); } mutex_unlock(&process_info->notifier_lock); @@ -2749,7 +2749,8 @@ unlock_out: /* If validation failed, reschedule another attempt */ if (evicted_bos) { - schedule_delayed_work(&process_info->restore_userptr_work, + queue_delayed_work(system_freezable_wq, + &process_info->restore_userptr_work, msecs_to_jiffies(AMDGPU_USERPTR_RESTORE_DELAY_MS)); kfd_smi_event_queue_restore_rescheduled(mm); @@ -2758,6 +2759,23 @@ unlock_out: put_task_struct(usertask); } +static void replace_eviction_fence(struct dma_fence **ef, + struct dma_fence *new_ef) +{ + struct dma_fence *old_ef = rcu_replace_pointer(*ef, new_ef, true + /* protected by process_info->lock */); + + /* If we're replacing an unsignaled eviction fence, that fence will + * never be signaled, and if anyone is still waiting on that fence, + * they will hang forever. This should never happen. We should only + * replace the fence in restore_work that only gets scheduled after + * eviction work signaled the fence. + */ + WARN_ONCE(!dma_fence_is_signaled(old_ef), + "Replacing unsignaled eviction fence"); + dma_fence_put(old_ef); +} + /** amdgpu_amdkfd_gpuvm_restore_process_bos - Restore all BOs for the given * KFD process identified by process_info * @@ -2781,7 +2799,6 @@ int amdgpu_amdkfd_gpuvm_restore_process_bos(void *info, struct dma_fence **ef) struct amdkfd_process_info *process_info = info; struct amdgpu_vm *peer_vm; struct kgd_mem *mem; - struct amdgpu_amdkfd_fence *new_fence; struct list_head duplicate_save; struct amdgpu_sync sync_obj; unsigned long failed_size = 0; @@ -2907,22 +2924,35 @@ int amdgpu_amdkfd_gpuvm_restore_process_bos(void *info, struct dma_fence **ef) /* Wait for validate and PT updates to finish */ amdgpu_sync_wait(&sync_obj, false); - /* Release old eviction fence and create new one, because fence only - * goes from unsignaled to signaled, fence cannot be reused. - * Use context and mm from the old fence. + /* The old eviction fence may be unsignaled if restore happens + * after a GPU reset or suspend/resume. Keep the old fence in that + * case. Otherwise release the old eviction fence and create new + * one, because fence only goes from unsignaled to signaled once + * and cannot be reused. Use context and mm from the old fence. + * + * If an old eviction fence signals after this check, that's OK. + * Anyone signaling an eviction fence must stop the queues first + * and schedule another restore worker. */ - new_fence = amdgpu_amdkfd_fence_create( + if (dma_fence_is_signaled(&process_info->eviction_fence->base)) { + struct amdgpu_amdkfd_fence *new_fence = + amdgpu_amdkfd_fence_create( process_info->eviction_fence->base.context, process_info->eviction_fence->mm, NULL); - if (!new_fence) { - pr_err("Failed to create eviction fence\n"); - ret = -ENOMEM; - goto validate_map_fail; + + if (!new_fence) { + pr_err("Failed to create eviction fence\n"); + ret = -ENOMEM; + goto validate_map_fail; + } + dma_fence_put(&process_info->eviction_fence->base); + process_info->eviction_fence = new_fence; + replace_eviction_fence(ef, dma_fence_get(&new_fence->base)); + } else { + WARN_ONCE(*ef != &process_info->eviction_fence->base, + "KFD eviction fence doesn't match KGD process_info"); } - dma_fence_put(&process_info->eviction_fence->base); - process_info->eviction_fence = new_fence; - *ef = dma_fence_get(&new_fence->base); /* Attach new eviction fence to all BOs except pinned ones */ list_for_each_entry(mem, &process_info->kfd_bo_list, validate_list) { diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c index c10d050e1a61..71df51fcc1b0 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c @@ -664,7 +664,8 @@ int kfd_process_create_wq(void) if (!kfd_process_wq) kfd_process_wq = alloc_workqueue("kfd_process_wq", 0, 0); if (!kfd_restore_wq) - kfd_restore_wq = alloc_ordered_workqueue("kfd_restore_wq", 0); + kfd_restore_wq = alloc_ordered_workqueue("kfd_restore_wq", + WQ_FREEZABLE); if (!kfd_process_wq || !kfd_restore_wq) { kfd_process_destroy_wq(); @@ -1642,6 +1643,7 @@ int kfd_process_device_init_vm(struct kfd_process_device *pdd, struct amdgpu_fpriv *drv_priv; struct amdgpu_vm *avm; struct kfd_process *p; + struct dma_fence *ef; struct kfd_node *dev; int ret; @@ -1661,11 +1663,12 @@ int kfd_process_device_init_vm(struct kfd_process_device *pdd, ret = amdgpu_amdkfd_gpuvm_acquire_process_vm(dev->adev, avm, &p->kgd_process_info, - &p->ef); + &ef); if (ret) { pr_err("Failed to create process VM object\n"); return ret; } + RCU_INIT_POINTER(p->ef, ef); pdd->drm_priv = drm_file->private_data; ret = kfd_process_device_reserve_ib_mem(pdd); @@ -1908,6 +1911,21 @@ kfd_process_gpuid_from_node(struct kfd_process *p, struct kfd_node *node, return -EINVAL; } +static int signal_eviction_fence(struct kfd_process *p) +{ + struct dma_fence *ef; + int ret; + + rcu_read_lock(); + ef = dma_fence_get_rcu_safe(&p->ef); + rcu_read_unlock(); + + ret = dma_fence_signal(ef); + dma_fence_put(ef); + + return ret; +} + static void evict_process_worker(struct work_struct *work) { int ret; @@ -1920,31 +1938,46 @@ static void evict_process_worker(struct work_struct *work) * lifetime of this thread, kfd_process p will be valid */ p = container_of(dwork, struct kfd_process, eviction_work); - WARN_ONCE(p->last_eviction_seqno != p->ef->seqno, - "Eviction fence mismatch\n"); - - /* Narrow window of overlap between restore and evict work - * item is possible. Once amdgpu_amdkfd_gpuvm_restore_process_bos - * unreserves KFD BOs, it is possible to evicted again. But - * restore has few more steps of finish. So lets wait for any - * previous restore work to complete - */ - flush_delayed_work(&p->restore_work); pr_debug("Started evicting pasid 0x%x\n", p->pasid); ret = kfd_process_evict_queues(p, KFD_QUEUE_EVICTION_TRIGGER_TTM); if (!ret) { - dma_fence_signal(p->ef); - dma_fence_put(p->ef); - p->ef = NULL; - queue_delayed_work(kfd_restore_wq, &p->restore_work, + /* If another thread already signaled the eviction fence, + * they are responsible stopping the queues and scheduling + * the restore work. + */ + if (!signal_eviction_fence(p)) + queue_delayed_work(kfd_restore_wq, &p->restore_work, msecs_to_jiffies(PROCESS_RESTORE_TIME_MS)); + else + kfd_process_restore_queues(p); pr_debug("Finished evicting pasid 0x%x\n", p->pasid); } else pr_err("Failed to evict queues of pasid 0x%x\n", p->pasid); } +static int restore_process_helper(struct kfd_process *p) +{ + int ret = 0; + + /* VMs may not have been acquired yet during debugging. */ + if (p->kgd_process_info) { + ret = amdgpu_amdkfd_gpuvm_restore_process_bos( + p->kgd_process_info, &p->ef); + if (ret) + return ret; + } + + ret = kfd_process_restore_queues(p); + if (!ret) + pr_debug("Finished restoring pasid 0x%x\n", p->pasid); + else + pr_err("Failed to restore queues of pasid 0x%x\n", p->pasid); + + return ret; +} + static void restore_process_worker(struct work_struct *work) { struct delayed_work *dwork; @@ -1970,24 +2003,15 @@ static void restore_process_worker(struct work_struct *work) */ p->last_restore_timestamp = get_jiffies_64(); - /* VMs may not have been acquired yet during debugging. */ - if (p->kgd_process_info) - ret = amdgpu_amdkfd_gpuvm_restore_process_bos(p->kgd_process_info, - &p->ef); + + ret = restore_process_helper(p); if (ret) { pr_debug("Failed to restore BOs of pasid 0x%x, retry after %d ms\n", p->pasid, PROCESS_BACK_OFF_TIME_MS); ret = queue_delayed_work(kfd_restore_wq, &p->restore_work, msecs_to_jiffies(PROCESS_BACK_OFF_TIME_MS)); WARN(!ret, "reschedule restore work failed\n"); - return; } - - ret = kfd_process_restore_queues(p); - if (!ret) - pr_debug("Finished restoring pasid 0x%x\n", p->pasid); - else - pr_err("Failed to restore queues of pasid 0x%x\n", p->pasid); } void kfd_suspend_all_processes(void) @@ -1998,14 +2022,9 @@ void kfd_suspend_all_processes(void) WARN(debug_evictions, "Evicting all processes"); hash_for_each_rcu(kfd_processes_table, temp, p, kfd_processes) { - cancel_delayed_work_sync(&p->eviction_work); - flush_delayed_work(&p->restore_work); - if (kfd_process_evict_queues(p, KFD_QUEUE_EVICTION_TRIGGER_SUSPEND)) pr_err("Failed to suspend process 0x%x\n", p->pasid); - dma_fence_signal(p->ef); - dma_fence_put(p->ef); - p->ef = NULL; + signal_eviction_fence(p); } srcu_read_unlock(&kfd_processes_srcu, idx); } @@ -2017,7 +2036,7 @@ int kfd_resume_all_processes(void) int ret = 0, idx = srcu_read_lock(&kfd_processes_srcu); hash_for_each_rcu(kfd_processes_table, temp, p, kfd_processes) { - if (!queue_delayed_work(kfd_restore_wq, &p->restore_work, 0)) { + if (restore_process_helper(p)) { pr_err("Restore process %d failed during resume\n", p->pasid); ret = -EFAULT; diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c index f2f3c338fd94..613f19510287 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c @@ -1870,7 +1870,7 @@ out_reschedule: /* If validation failed, reschedule another attempt */ if (evicted_ranges) { pr_debug("reschedule to restore svm range\n"); - schedule_delayed_work(&svms->restore_work, + queue_delayed_work(system_freezable_wq, &svms->restore_work, msecs_to_jiffies(AMDGPU_SVM_RANGE_RESTORE_DELAY_MS)); kfd_smi_event_queue_restore_rescheduled(mm); @@ -1946,7 +1946,7 @@ svm_range_evict(struct svm_range *prange, struct mm_struct *mm, pr_debug("failed to quiesce KFD\n"); pr_debug("schedule to restore svm %p ranges\n", svms); - schedule_delayed_work(&svms->restore_work, + queue_delayed_work(system_freezable_wq, &svms->restore_work, msecs_to_jiffies(AMDGPU_SVM_RANGE_RESTORE_DELAY_MS)); } else { unsigned long s, l;