Am 22.09.21 um 16:36 schrieb Tvrtko Ursulin:
+
+/**
+ * dma_resv_iter_first_unlocked - first fence in an unlocked
dma_resv obj.
+ * @cursor: the cursor with the current position
+ *
+ * Returns the first fence from an unlocked dma_resv obj.
+ */
+struct dma_fence *dma_resv_iter_first_unlocked(struct dma_resv_iter
*cursor)
+{
+ rcu_read_lock();
+ do {
+ dma_resv_iter_restart_unlocked(cursor);
+ dma_resv_iter_walk_unlocked(cursor);
+ } while (read_seqcount_retry(&cursor->obj->seq, cursor->seq));
+ rcu_read_unlock();
+
+ return cursor->fence;
+}
+EXPORT_SYMBOL(dma_resv_iter_first_unlocked);
Why is this one split from dma_resv_iter_begin and even exported?
I've split it to be able to use dma_resv_iter_begin in both the unlocked
and locked iterator.
I couldn't find any users in the series.
This is used in the dma_resv_for_each_fence_unlocked() macro to return
the first fence.
+
+/**
+ * dma_resv_iter_next_unlocked - next fence in an unlocked dma_resv
obj.
+ * @cursor: the cursor with the current position
+ *
+ * Returns the next fence from an unlocked dma_resv obj.
+ */
+struct dma_fence *dma_resv_iter_next_unlocked(struct dma_resv_iter
*cursor)
+{
+ bool restart;
+
+ rcu_read_lock();
+ cursor->is_restarted = false;
+ restart = read_seqcount_retry(&cursor->obj->seq, cursor->seq);
+ do {
+ if (restart)
+ dma_resv_iter_restart_unlocked(cursor);
+ dma_resv_iter_walk_unlocked(cursor);
+ restart = true;
+ } while (read_seqcount_retry(&cursor->obj->seq, cursor->seq));
+ rcu_read_unlock();
+
+ return cursor->fence;
+}
+EXPORT_SYMBOL(dma_resv_iter_next_unlocked);
Couldn't dma_resv_iter_first_unlocked and dma_resv_iter_next_unlocked
share the same implementation? Especially if you are able to replace
cursor->is_restarted with cursor->index == -1.
That's what I had initially, but Daniel disliked it for some reason. You
then need a centralized walk function instead of first/next.
Thanks,
Christian.
Regards,
Tvrtko
