From 5e45d7dfd74100d622f9cdc70bfd1f9fae1671de Mon Sep 17 00:00:00 2001 From: Maarten Lankhorst Date: Tue, 15 Jan 2013 14:57:05 +0100 Subject: drm/ttm: add ttm_bo_reserve_slowpath Instead of dropping everything, waiting for the bo to be unreserved and trying over, a better strategy would be to do a blocking wait. This can be mapped a lot better to a mutex_lock-like call. Signed-off-by: Maarten Lankhorst Reviewed-by: Jerome Glisse --- drivers/gpu/drm/ttm/ttm_bo.c | 47 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) (limited to 'drivers/gpu/drm/ttm') diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c index e8e4814b1295..4dd6f9e77a7d 100644 --- a/drivers/gpu/drm/ttm/ttm_bo.c +++ b/drivers/gpu/drm/ttm/ttm_bo.c @@ -310,6 +310,53 @@ int ttm_bo_reserve(struct ttm_buffer_object *bo, return ret; } +int ttm_bo_reserve_slowpath_nolru(struct ttm_buffer_object *bo, + bool interruptible, uint32_t sequence) +{ + bool wake_up = false; + int ret; + + while (unlikely(atomic_xchg(&bo->reserved, 1) != 0)) { + WARN_ON(bo->seq_valid && sequence == bo->val_seq); + + ret = ttm_bo_wait_unreserved(bo, interruptible); + + if (unlikely(ret)) + return ret; + } + + if ((bo->val_seq - sequence < (1 << 31)) || !bo->seq_valid) + wake_up = true; + + /** + * Wake up waiters that may need to recheck for deadlock, + * if we decreased the sequence number. + */ + bo->val_seq = sequence; + bo->seq_valid = true; + if (wake_up) + wake_up_all(&bo->event_queue); + + return 0; +} + +int ttm_bo_reserve_slowpath(struct ttm_buffer_object *bo, + bool interruptible, uint32_t sequence) +{ + struct ttm_bo_global *glob = bo->glob; + int put_count, ret; + + ret = ttm_bo_reserve_slowpath_nolru(bo, interruptible, sequence); + if (likely(!ret)) { + spin_lock(&glob->lru_lock); + put_count = ttm_bo_del_from_lru(bo); + spin_unlock(&glob->lru_lock); + ttm_bo_list_ref_sub(bo, put_count, true); + } + return ret; +} +EXPORT_SYMBOL(ttm_bo_reserve_slowpath); + void ttm_bo_unreserve_locked(struct ttm_buffer_object *bo) { ttm_bo_add_to_lru(bo); -- cgit v1.2.3