[PATCH v3 05/16] net/af_xdp: use previous value atomic fetch operations

[Tyler Retzlaff]

Use __atomic_fetch_{add,and,or,sub,xor} instead of
__atomic_{add,and,or,sub,xor}_fetch adding the necessary code to
allow consumption of the resulting value.

Signed-off-by: Tyler Retzlaff <roretzla at linux.microsoft.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang at arm.com>
---
 drivers/net/af_xdp/rte_eth_af_xdp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c b/drivers/net/af_xdp/rte_eth_af_xdp.c
index 2a20a69..c7786cc 100644
--- a/drivers/net/af_xdp/rte_eth_af_xdp.c
+++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
@@ -979,7 +979,7 @@ static int link_xdp_prog_with_dev(int ifindex, int fd, __u32 flags)
 			break;
 		xsk_socket__delete(rxq->xsk);
 
-		if (__atomic_sub_fetch(&rxq->umem->refcnt, 1, __ATOMIC_ACQUIRE)
+		if (__atomic_fetch_sub(&rxq->umem->refcnt, 1, __ATOMIC_ACQUIRE) - 1
 				== 0) {
 			(void)xsk_umem__delete(rxq->umem->umem);
 			xdp_umem_destroy(rxq->umem);
@@ -1710,7 +1710,7 @@ struct msg_internal {
 out_xsk:
 	xsk_socket__delete(rxq->xsk);
 out_umem:
-	if (__atomic_sub_fetch(&rxq->umem->refcnt, 1, __ATOMIC_ACQUIRE) == 0)
+	if (__atomic_fetch_sub(&rxq->umem->refcnt, 1, __ATOMIC_ACQUIRE) - 1 == 0)
 		xdp_umem_destroy(rxq->umem);
 
 	return ret;
-- 
1.8.3.1