This makes the function much simpler since the complex
retry logic is now handled else where.
Signed-off-by: Christian König <christian.koenig@xxxxxxx>
---
drivers/dma-buf/dma-resv.c | 86 ++++++++++++++++----------------------
1 file changed, 35 insertions(+), 51 deletions(-)
diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
index a3c79a99fb44..406150dea5e4 100644
--- a/drivers/dma-buf/dma-resv.c
+++ b/drivers/dma-buf/dma-resv.c
@@ -426,74 +426,58 @@ EXPORT_SYMBOL_GPL(dma_resv_iter_walk);
*/
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);
-
-retry:
- if (src_list) {
- unsigned int shared_count = src_list->shared_count;
-
- rcu_read_unlock();
+ list = NULL;
+ excl = NULL;
- dst_list = dma_resv_list_alloc(shared_count);
- if (!dst_list)
- return -ENOMEM;
+ rcu_read_lock();
+ dma_resv_iter_begin(&cursor, src, true);
+ dma_resv_for_each_fence_unlocked(&cursor, f) {
- rcu_read_lock();
- src_list = dma_resv_shared_list(src);
- if (!src_list || src_list->shared_count > shared_count) {
- kfree(dst_list);
- goto retry;
- }
+ if (cursor.is_first) {
+ dma_resv_list_free(list);
+ dma_fence_put(excl);
- dst_list->shared_count = 0;
- for (i = 0; i < src_list->shared_count; ++i) {
- struct dma_fence __rcu **dst;
- struct dma_fence *fence;
+ if (cursor.fences) {
+ unsigned int cnt = cursor.fences->shared_count;
- fence = rcu_dereference(src_list->shared[i]);
- if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
- &fence->flags))
- continue;
+ rcu_read_unlock();
+ list = dma_resv_list_alloc(cnt);
+ if (!list) {
+ dma_resv_iter_end(&cursor);
+ return -ENOMEM;
+ }
- if (!dma_fence_get_rcu(fence)) {
- dma_resv_list_free(dst_list);
- src_list = dma_resv_shared_list(src);
- goto retry;
- }
+ list->shared_count = 0;
+ rcu_read_lock();
- if (dma_fence_is_signaled(fence)) {
- dma_fence_put(fence);
- continue;
+ } else {
+ list = NULL;
}
-
- 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);
+ 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);
rcu_read_unlock();
- src_list = dma_resv_shared_list(dst);
- old = dma_resv_excl_fence(dst);
-
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;
}
--
2.25.1
