diff options
| -rw-r--r-- | drivers/dma-buf/dma-resv.c | 84 |
1 files changed, 32 insertions, 52 deletions
diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index 3cbcf66a137e..08e5b8c381f4 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -432,74 +432,54 @@ EXPORT_SYMBOL(dma_resv_iter_next_unlocked); */ int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src) { - struct dma_resv_list *src_list, *dst_list; - struct dma_fence *old, *new; - unsigned int i; + struct dma_resv_iter cursor; + struct dma_resv_list *list; + struct dma_fence *f, *excl; dma_resv_assert_held(dst); - rcu_read_lock(); - src_list = dma_resv_shared_list(src); + list = NULL; + excl = NULL; -retry: - if (src_list) { - unsigned int shared_count = src_list->shared_count; + dma_resv_iter_begin(&cursor, src, true); + dma_resv_for_each_fence_unlocked(&cursor, f) { - rcu_read_unlock(); + if (dma_resv_iter_is_restarted(&cursor)) { + dma_resv_list_free(list); + dma_fence_put(excl); - dst_list = dma_resv_list_alloc(shared_count); - if (!dst_list) - return -ENOMEM; + if (cursor.fences) { + unsigned int cnt = cursor.fences->shared_count; - rcu_read_lock(); - src_list = dma_resv_shared_list(src); - if (!src_list || src_list->shared_count > shared_count) { - kfree(dst_list); - goto retry; - } - - dst_list->shared_count = 0; - for (i = 0; i < src_list->shared_count; ++i) { - struct dma_fence __rcu **dst; - struct dma_fence *fence; + list = dma_resv_list_alloc(cnt); + if (!list) { + dma_resv_iter_end(&cursor); + return -ENOMEM; + } - fence = rcu_dereference(src_list->shared[i]); - if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, - &fence->flags)) - continue; + list->shared_count = 0; - if (!dma_fence_get_rcu(fence)) { - dma_resv_list_free(dst_list); - src_list = dma_resv_shared_list(src); - goto retry; + } else { + list = NULL; } - - if (dma_fence_is_signaled(fence)) { - dma_fence_put(fence); - continue; - } - - dst = &dst_list->shared[dst_list->shared_count++]; - rcu_assign_pointer(*dst, fence); + excl = NULL; } - } else { - dst_list = NULL; - } - new = dma_fence_get_rcu_safe(&src->fence_excl); - rcu_read_unlock(); - - src_list = dma_resv_shared_list(dst); - old = dma_resv_excl_fence(dst); + dma_fence_get(f); + if (dma_resv_iter_is_exclusive(&cursor)) + excl = f; + else + RCU_INIT_POINTER(list->shared[list->shared_count++], f); + } + dma_resv_iter_end(&cursor); write_seqcount_begin(&dst->seq); - /* write_seqcount_begin provides the necessary memory barrier */ - RCU_INIT_POINTER(dst->fence_excl, new); - RCU_INIT_POINTER(dst->fence, dst_list); + excl = rcu_replace_pointer(dst->fence_excl, excl, dma_resv_held(dst)); + list = rcu_replace_pointer(dst->fence, list, dma_resv_held(dst)); write_seqcount_end(&dst->seq); - dma_resv_list_free(src_list); - dma_fence_put(old); + dma_resv_list_free(list); + dma_fence_put(excl); return 0; } |