diff options
| -rw-r--r-- | drivers/gpu/drm/ttm/ttm_bo.c | 35 | ||||
| -rw-r--r-- | drivers/gpu/drm/ttm/ttm_bo_vm.c | 26 | ||||
| -rw-r--r-- | include/drm/ttm/ttm_bo_api.h | 4 |
3 files changed, 57 insertions, 8 deletions
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c index 8d5a646ebe6a..07e02c4bf5a8 100644 --- a/drivers/gpu/drm/ttm/ttm_bo.c +++ b/drivers/gpu/drm/ttm/ttm_bo.c @@ -151,7 +151,7 @@ static void ttm_bo_release_list(struct kref *list_kref) atomic_dec(&bo->glob->bo_count); if (bo->resv == &bo->ttm_resv) reservation_object_fini(&bo->ttm_resv); - + mutex_destroy(&bo->wu_mutex); if (bo->destroy) bo->destroy(bo); else { @@ -1123,6 +1123,7 @@ int ttm_bo_init(struct ttm_bo_device *bdev, INIT_LIST_HEAD(&bo->ddestroy); INIT_LIST_HEAD(&bo->swap); INIT_LIST_HEAD(&bo->io_reserve_lru); + mutex_init(&bo->wu_mutex); bo->bdev = bdev; bo->glob = bdev->glob; bo->type = type; @@ -1704,3 +1705,35 @@ void ttm_bo_swapout_all(struct ttm_bo_device *bdev) ; } EXPORT_SYMBOL(ttm_bo_swapout_all); + +/** + * ttm_bo_wait_unreserved - interruptible wait for a buffer object to become + * unreserved + * + * @bo: Pointer to buffer + */ +int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo) +{ + int ret; + + /* + * In the absense of a wait_unlocked API, + * Use the bo::wu_mutex to avoid triggering livelocks due to + * concurrent use of this function. Note that this use of + * bo::wu_mutex can go away if we change locking order to + * mmap_sem -> bo::reserve. + */ + ret = mutex_lock_interruptible(&bo->wu_mutex); + if (unlikely(ret != 0)) + return -ERESTARTSYS; + if (!ww_mutex_is_locked(&bo->resv->lock)) + goto out_unlock; + ret = ttm_bo_reserve_nolru(bo, true, false, false, NULL); + if (unlikely(ret != 0)) + goto out_unlock; + ww_mutex_unlock(&bo->resv->lock); + +out_unlock: + mutex_unlock(&bo->wu_mutex); + return ret; +} diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index ac617f3ecd0c..b249ab9b1eb2 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -107,13 +107,28 @@ static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) /* * Work around locking order reversal in fault / nopfn * between mmap_sem and bo_reserve: Perform a trylock operation - * for reserve, and if it fails, retry the fault after scheduling. + * for reserve, and if it fails, retry the fault after waiting + * for the buffer to become unreserved. */ - - ret = ttm_bo_reserve(bo, true, true, false, 0); + ret = ttm_bo_reserve(bo, true, true, false, NULL); if (unlikely(ret != 0)) { - if (ret == -EBUSY) - set_need_resched(); + if (ret != -EBUSY) + return VM_FAULT_NOPAGE; + + if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) { + if (!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) { + up_read(&vma->vm_mm->mmap_sem); + (void) ttm_bo_wait_unreserved(bo); + } + + return VM_FAULT_RETRY; + } + + /* + * If we'd want to change locking order to + * mmap_sem -> bo::reserve, we'd use a blocking reserve here + * instead of retrying the fault... + */ return VM_FAULT_NOPAGE; } @@ -123,7 +138,6 @@ static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) case 0: break; case -EBUSY: - set_need_resched(); case -ERESTARTSYS: retval = VM_FAULT_NOPAGE; goto out_unlock; diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h index 751eaffbf0d5..ee127ec33c60 100644 --- a/include/drm/ttm/ttm_bo_api.h +++ b/include/drm/ttm/ttm_bo_api.h @@ -169,6 +169,7 @@ struct ttm_tt; * @offset: The current GPU offset, which can have different meanings * depending on the memory type. For SYSTEM type memory, it should be 0. * @cur_placement: Hint of current placement. + * @wu_mutex: Wait unreserved mutex. * * Base class for TTM buffer object, that deals with data placement and CPU * mappings. GPU mappings are really up to the driver, but for simpler GPUs @@ -250,6 +251,7 @@ struct ttm_buffer_object { struct reservation_object *resv; struct reservation_object ttm_resv; + struct mutex wu_mutex; }; /** @@ -702,5 +704,5 @@ extern ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp, size_t count, loff_t *f_pos, bool write); extern void ttm_bo_swapout_all(struct ttm_bo_device *bdev); - +extern int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo); #endif |
