From 0f4a647d6ac689df7b65a581cd76765242de7af0 Mon Sep 17 00:00:00 2001
From: Luo bin <luobin9@huawei.com>
Date: Fri, 20 Mar 2020 23:13:18 +0000
Subject: [PATCH] hinic: fix out-of-order excution in arm cpu

commit 33f15da216a1f4566b4ec880942556ace30615df upstream.

add read barrier in driver code to keep from reading other fileds
in dma memory which is writable for hw until we have verified the
memory is valid for driver

Signed-off-by: Luo bin <luobin9@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/net/ethernet/huawei/hinic/hinic_hw_cmdq.c b/drivers/net/ethernet/huawei/hinic/hinic_hw_cmdq.c
index eb53c15b13f3..33f93cc25193 100644
--- a/drivers/net/ethernet/huawei/hinic/hinic_hw_cmdq.c
+++ b/drivers/net/ethernet/huawei/hinic/hinic_hw_cmdq.c
@@ -623,6 +623,8 @@ static int cmdq_cmd_ceq_handler(struct hinic_cmdq *cmdq, u16 ci,
 	if (!CMDQ_WQE_COMPLETED(be32_to_cpu(ctrl->ctrl_info)))
 		return -EBUSY;
 
+	dma_rmb();
+
 	errcode = CMDQ_WQE_ERRCODE_GET(be32_to_cpu(status->status_info), VAL);
 
 	cmdq_sync_cmd_handler(cmdq, ci, errcode);
diff --git a/drivers/net/ethernet/huawei/hinic/hinic_hw_eqs.c b/drivers/net/ethernet/huawei/hinic/hinic_hw_eqs.c
index 6a723c4757bc..c0b6bcb067cd 100644
--- a/drivers/net/ethernet/huawei/hinic/hinic_hw_eqs.c
+++ b/drivers/net/ethernet/huawei/hinic/hinic_hw_eqs.c
@@ -235,6 +235,8 @@ static void aeq_irq_handler(struct hinic_eq *eq)
 		if (HINIC_EQ_ELEM_DESC_GET(aeqe_desc, WRAPPED) == eq->wrapped)
 			break;
 
+		dma_rmb();
+
 		event = HINIC_EQ_ELEM_DESC_GET(aeqe_desc, TYPE);
 		if (event >= HINIC_MAX_AEQ_EVENTS) {
 			dev_err(&pdev->dev, "Unknown AEQ Event %d\n", event);
diff --git a/drivers/net/ethernet/huawei/hinic/hinic_rx.c b/drivers/net/ethernet/huawei/hinic/hinic_rx.c
index 1225e65d8bcd..9fa64a1c5742 100644
--- a/drivers/net/ethernet/huawei/hinic/hinic_rx.c
+++ b/drivers/net/ethernet/huawei/hinic/hinic_rx.c
@@ -327,6 +327,9 @@ static int rxq_recv(struct hinic_rxq *rxq, int budget)
 		if (!rq_wqe)
 			break;
 
+		/* make sure we read rx_done before packet length */
+		dma_rmb();
+
 		hinic_rq_get_sge(rxq->rq, rq_wqe, ci, &sge);
 
 		rx_unmap_skb(rxq, hinic_sge_to_dma(&sge));
diff --git a/drivers/net/ethernet/huawei/hinic/hinic_tx.c b/drivers/net/ethernet/huawei/hinic/hinic_tx.c
index b9fd8d720349..5635b840275c 100644
--- a/drivers/net/ethernet/huawei/hinic/hinic_tx.c
+++ b/drivers/net/ethernet/huawei/hinic/hinic_tx.c
@@ -597,6 +597,8 @@ static int free_tx_poll(struct napi_struct *napi, int budget)
 	do {
 		hw_ci = HW_CONS_IDX(sq) & wq->mask;
 
+		dma_rmb();
+
 		/* Reading a WQEBB to get real WQE size and consumer index. */
 		sq_wqe = hinic_sq_read_wqebb(sq, &skb, &wqe_size, &sw_ci);
 		if ((!sq_wqe) ||
-- 
2.7.4