[PATCH 07/16] dma-buf: use new iterator in dma_buf_poll

[Christian König]

This makes the function much simpler since the complex
retry logic is now handled elsewhere.

Signed-off-by: Christian König <christian.koe...@amd.com>
---
 drivers/dma-buf/dma-buf.c | 49 ++++-----------------------------------
 1 file changed, 4 insertions(+), 45 deletions(-)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index b67fbf4e3705..4173f1f70ac1 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -207,15 +207,13 @@ static void dma_buf_poll_cb(struct dma_fence *fence, 
struct dma_fence_cb *cb)
 
 static __poll_t dma_buf_poll(struct file *file, poll_table *poll)
 {
+       struct dma_resv_cursor cursor;
        struct dma_buf_poll_cb_t *dcb;
        struct dma_buf *dmabuf;
        struct dma_resv *resv;
-       struct dma_resv_list *fobj;
-       struct dma_fence *fence_excl;
-       unsigned shared_count, seq;
        struct dma_fence *fence;
        __poll_t events;
-       int r, i;
+       int r;
 
        dmabuf = file->private_data;
        if (!dmabuf || !dmabuf->resv)
@@ -241,53 +239,14 @@ static __poll_t dma_buf_poll(struct file *file, 
poll_table *poll)
        if (!events)
                return 0;
 
-retry:
-       seq = read_seqcount_begin(&resv->seq);
-       rcu_read_lock();
-
-       fobj = rcu_dereference(resv->fence);
-       if (fobj && events & EPOLLOUT)
-               shared_count = fobj->shared_count;
-       else
-               shared_count = 0;
-
-       for (i = 0; i < shared_count; ++i) {
-               fence = rcu_dereference(fobj->shared[i]);
-               fence = dma_fence_get_rcu(fence);
-               if (!fence || read_seqcount_retry(&resv->seq, seq)) {
-                       /* Concurrent modify detected, force re-check */
-                       dma_fence_put(fence);
-                       rcu_read_unlock();
-                       goto retry;
-               }
-
-               r = dma_fence_add_callback(fence, &dcb->cb, dma_buf_poll_cb);
-               if (!r) {
-                       /* Callback queued */
-                       events = 0;
-                       goto out;
-               }
-               dma_fence_put(fence);
-       }
-
-       fence = dma_resv_excl_fence(resv);
-       if (fence) {
-               fence = dma_fence_get_rcu(fence);
-               if (!fence || read_seqcount_retry(&resv->seq, seq)) {
-                       /* Concurrent modify detected, force re-check */
-                       dma_fence_put(fence);
-                       rcu_read_unlock();
-                       goto retry;
-
-               }
-
+       dma_resv_for_each_fence_unlocked(resv, &cursor, events & EPOLLOUT,
+                                        fence) {
                r = dma_fence_add_callback(fence, &dcb->cb, dma_buf_poll_cb);
                if (!r) {
                        /* Callback queued */
                        events = 0;
                        goto out;
                }
-               dma_fence_put(fence_excl);
        }
 
        /* No callback queued, wake up any additional waiters. */
-- 
2.25.1