From 1a42156f52bd4de0e2442671bc24b7ffc7b01c52 Mon Sep 17 00:00:00 2001

From: Lijun Pan <ljp@linux.ibm.com>

Date: Fri, 12 Feb 2021 20:36:46 -0600

Subject: [PATCH] ibmvnic: substitute mb() with dma_wmb() for send_*crq*

 functions

References: bsc#1184114 ltc#192237 bsc#1183023 ltc#191791

Patch-mainline: v5.12-rc1

Git-commit: 1a42156f52bd4de0e2442671bc24b7ffc7b01c52

The CRQ and subCRQ descriptors are DMA mapped, so dma_wmb(),

though weaker, is good enough to protect the data structures.

Signed-off-by: Lijun Pan <ljp@linux.ibm.com>

Acked-by: Thomas Falcon <tlfalcon@linux.ibm.com>

Signed-off-by: David S. Miller <davem@davemloft.net>

Acked-by: Michal Suchanek <msuchanek@suse.de>

---

 drivers/net/ethernet/ibm/ibmvnic.c | 4 ++--

 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c

index 7a5e589e7223..927d5f36d308 100644

--- a/drivers/net/ethernet/ibm/ibmvnic.c

+++ b/drivers/net/ethernet/ibm/ibmvnic.c

@@ -3599,7 +3599,7 @@ static int send_subcrq_indirect(struct ibmvnic_adapter *adapter,

 	int rc;

 	/* Make sure the hypervisor sees the complete request */

-	mb();

+	dma_wmb();

 	rc = plpar_hcall_norets(H_SEND_SUB_CRQ_INDIRECT, ua,

 				cpu_to_be64(remote_handle),

 				ioba, num_entries);

@@ -3629,7 +3629,7 @@ static int ibmvnic_send_crq(struct ibmvnic_adapter *adapter,

 	}

 	/* Make sure the hypervisor sees the complete request */

-	mb();

+	dma_wmb();

 	rc = plpar_hcall_norets(H_SEND_CRQ, ua,

 				cpu_to_be64(u64_crq[0]),

-- 

2.26.2