[dpdk-stable] [PATCH] net/mlx5: fix incorrect r/w lock usage in DMA unmap

[Feifei Wang <feifei.wang2@arm.com>]

For mlx5 DMA unmap, write lock should be used for rebuilding memory
region cache table rather than read lock.

Fixes: 989e999d9305 ("net/mlx5: support PCI device DMA map and unmap")
Cc: shahafs@mellanox.com
Cc: stable@dpdk.org

Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
---
 drivers/net/mlx5/mlx5_mr.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_mr.c b/drivers/net/mlx5/mlx5_mr.c
index e791b6338d..45a122f4f9 100644
--- a/drivers/net/mlx5/mlx5_mr.c
+++ b/drivers/net/mlx5/mlx5_mr.c
@@ -395,10 +395,10 @@ mlx5_dma_unmap(struct rte_pci_device *pdev, void *addr,
 	}
 	priv = dev->data->dev_private;
 	sh = priv->sh;
-	rte_rwlock_read_lock(&sh->share_cache.rwlock);
+	rte_rwlock_write_lock(&sh->share_cache.rwlock);
 	mr = mlx5_mr_lookup_list(&sh->share_cache, &entry, (uintptr_t)addr);
 	if (!mr) {
-		rte_rwlock_read_unlock(&sh->share_cache.rwlock);
+		rte_rwlock_write_unlock(&sh->share_cache.rwlock);
 		DRV_LOG(WARNING, "address 0x%" PRIxPTR " wasn't registered "
 				 "to PCI device %p", (uintptr_t)addr,
 				 (void *)pdev);
@@ -423,7 +423,7 @@ mlx5_dma_unmap(struct rte_pci_device *pdev, void *addr,
 	DRV_LOG(DEBUG, "broadcasting local cache flush, gen=%d",
 	      sh->share_cache.dev_gen);
 	rte_smp_wmb();
-	rte_rwlock_read_unlock(&sh->share_cache.rwlock);
+	rte_rwlock_write_unlock(&sh->share_cache.rwlock);
 	return 0;
 }
 
-- 
2.25.1