[PATCH io_uring 09/16] io_uring/zcrx: add helper for deriving area token

[Pavel Begunkov <asml.silence@gmail.com>]

Add zcrx_area_id_to_token() to deduplicate the way the area token is
calculated out of the area index.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 io_uring/zcrx.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c
index bea606beaf4f..5b46e1335079 100644
--- a/io_uring/zcrx.c
+++ b/io_uring/zcrx.c
@@ -39,6 +39,11 @@
 
 #define IO_DMA_ATTR (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING)
 
+static inline u64 zcrx_area_id_to_token(u32 area_id)
+{
+	return (u64)area_id << IORING_ZCRX_AREA_SHIFT;
+}
+
 static inline struct io_zcrx_ifq *io_pp_to_ifq(struct page_pool *pp)
 {
 	return pp->mp_priv;
@@ -526,7 +531,7 @@ static int io_zcrx_create_area(struct io_zcrx_ifq *ifq,
 	area->free_count = nr_iovs;
 	/* we're only supporting one area per ifq for now */
 	area->area_id = 0;
-	area_reg->rq_area_token = (u64)area->area_id << IORING_ZCRX_AREA_SHIFT;
+	area_reg->rq_area_token = zcrx_area_id_to_token(area->area_id);
 	spin_lock_init(&area->freelist_lock);
 
 	ret = io_zcrx_append_area(ifq, area);
@@ -1533,7 +1538,7 @@ static bool io_zcrx_queue_cqe(struct io_kiocb *req, struct net_iov *niov,
 	area = io_zcrx_iov_to_area(niov);
 	offset = off + (net_iov_idx(niov) << ifq->niov_shift);
 	rcqe = (struct io_uring_zcrx_cqe *)(cqe + 1);
-	rcqe->off = offset + ((u64)area->area_id << IORING_ZCRX_AREA_SHIFT);
+	rcqe->off = offset + zcrx_area_id_to_token(area->area_id);
 	rcqe->__pad = 0;
 	return true;
 }
-- 
2.54.0