[dpdk-dev] [memnic PATCH] pmd: use memory barrier function instead of asm volatile

[Olivier Matz]

Use the DPDK specific function rte_mb() instead of
the GCC statement asm volatile ("" ::: "memory").

Signed-off-by: Olivier Matz <olivier.matz at 6wind.com>
---
 common/memnic.h  | 2 --
 pmd/pmd_memnic.c | 6 +++---
 2 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/common/memnic.h b/common/memnic.h
index 6ff38a0..fdc9fa3 100644
--- a/common/memnic.h
+++ b/common/memnic.h
@@ -123,8 +123,6 @@ struct memnic_area {
 /* for userspace */
 #define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))

-#define barrier() do { asm volatile("": : :"memory"); } while (0)
-
 static inline uint32_t cmpxchg(uint32_t *dst, uint32_t old, uint32_t new)
 {
        volatile uint32_t *ptr = (volatile uint32_t *)dst;
diff --git a/pmd/pmd_memnic.c b/pmd/pmd_memnic.c
index bc01746..1586222 100644
--- a/pmd/pmd_memnic.c
+++ b/pmd/pmd_memnic.c
@@ -100,7 +100,7 @@ static int memnic_dev_start(struct rte_eth_dev *dev)

        /* invalidate */
        adapter->nic->hdr.valid = 0;
-       barrier();
+       rte_mb();
        /* reset */
        adapter->nic->hdr.reset = 1;
        /* no need to wait here */
@@ -242,7 +242,7 @@ static uint16_t memnic_recv_pkts(void *rx_queue,
                mb->pkt.data_len = p->len;
                rx_pkts[nr] = mb;

-               barrier();
+               rte_mb();
                p->status = MEMNIC_PKT_ST_FREE;

                if (++idx >= MEMNIC_NR_PACKET)
@@ -290,7 +290,7 @@ retry:

                rte_memcpy(p->data, rte_pktmbuf_mtod(tx_pkts[nr], void *), len);

-               barrier();
+               rte_mb();
                p->status = MEMNIC_PKT_ST_FILLED;

                rte_pktmbuf_free(tx_pkts[nr]);
-- 
1.8.4.rc3