From da966b82bf3d16f89a05732c933a589ec798d3f7 Mon Sep 17 00:00:00 2001 From: Thomas Hellström Date: Fri, 5 Jul 2024 17:32:03 +0200 Subject: drm/ttm: Provide a generic LRU walker helper MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Provide a generic LRU walker in TTM, in the spirit of drm_gem_lru_scan() but building on the restartable TTM LRU functionality. The LRU walker optionally supports locking objects as part of a ww mutex locking transaction, to mimic to some extent the current functionality in ttm. However any -EDEADLK return is converted to -ENOSPC and then to -ENOMEM before reaching the driver, so that the driver will need to backoff and possibly retry without being able to keep the ticket. v3: - Move the helper to core ttm. - Remove the drm_exec usage from it for now, it will be reintroduced later in the series. v4: - Handle the -EALREADY case if ticketlocking. v6: - Some cleanup and added code comments (Matthew Brost) - Clarified the ticketlock in the commit message (Matthew Brost) v7: - Use s64 rather than long for the target and progress (Christian König) - Update documentation to not encourage using pages as a progress measure. (Christian König) - Remove cond_resched(). (Christian König) Cc: Christian König Cc: Somalapuram Amaranath Cc: Matthew Brost Cc: Signed-off-by: Thomas Hellström Reviewed-by: Matthew Brost #v6 Link: https://patchwork.freedesktop.org/patch/msgid/20240705153206.68526-6-thomas.hellstrom@linux.intel.com Signed-off-by: Christian König --- include/drm/ttm/ttm_bo.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'include/drm/ttm') diff --git a/include/drm/ttm/ttm_bo.h b/include/drm/ttm/ttm_bo.h index ef0f52f56ebc..21fa9d5964ec 100644 --- a/include/drm/ttm/ttm_bo.h +++ b/include/drm/ttm/ttm_bo.h @@ -194,6 +194,41 @@ struct ttm_operation_ctx { uint64_t bytes_moved; }; +struct ttm_lru_walk; + +/** struct ttm_lru_walk_ops - Operations for a LRU walk. */ +struct ttm_lru_walk_ops { + /** + * process_bo - Process this bo. + * @walk: struct ttm_lru_walk describing the walk. + * @bo: A locked and referenced buffer object. + * + * Return: Negative error code on error, User-defined positive value + * (typically, but not always, size of the processed bo) on success. + * On success, the returned values are summed by the walk and the + * walk exits when its target is met. + * 0 also indicates success, -EBUSY means this bo was skipped. + */ + s64 (*process_bo)(struct ttm_lru_walk *walk, struct ttm_buffer_object *bo); +}; + +/** + * struct ttm_lru_walk - Structure describing a LRU walk. + */ +struct ttm_lru_walk { + /** @ops: Pointer to the ops structure. */ + const struct ttm_lru_walk_ops *ops; + /** @ctx: Pointer to the struct ttm_operation_ctx. */ + struct ttm_operation_ctx *ctx; + /** @ticket: The struct ww_acquire_ctx if any. */ + struct ww_acquire_ctx *ticket; + /** @tryock_only: Only use trylock for locking. */ + bool trylock_only; +}; + +s64 ttm_lru_walk_for_evict(struct ttm_lru_walk *walk, struct ttm_device *bdev, + struct ttm_resource_manager *man, s64 target); + /** * ttm_bo_get - reference a struct ttm_buffer_object * -- cgit v1.3.1