net: hns3: use appropriate barrier function after setting a bit value

[ Upstream commit 094c281228529d333458208fd02fcac3b139d93b ]

There is a memory barrier in followed case. When set the port down,
hclgevf_set_timmer will set DOWN in state. Meanwhile, the service task has
different behaviour based on whether the state is DOWN. Thus, to make sure
service task see DOWN, use smp_mb__after_atomic after calling set_bit().

          CPU0                        CPU1
========================== ===================================
hclgevf_set_timer_task()    hclgevf_periodic_service_task()
  set_bit(DOWN,state)         test_bit(DOWN,state)

pf also has this issue.

Fixes: ff200099d271 ("net: hns3: remove unnecessary work in hclgevf_main")
Fixes: 1c6dfe6fc6f7 ("net: hns3: remove mailbox and reset work in hclge_main")
Signed-off-by: Peiyang Wang <wangpeiyang1@huawei.com>
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
index a0a64441199c50931c185a118a0d30ae91500ac3..4b0027a41f3cdceca5a6902b9ebc762f69f179c7 100644 (file)
--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
@@ -8156,8 +8156,7 @@ static void hclge_set_timer_task(struct hnae3_handle *handle, bool enable)
                /* Set the DOWN flag here to disable link updating */
                set_bit(HCLGE_STATE_DOWN, &hdev->state);
 
-               /* flush memory to make sure DOWN is seen by service task */
-               smp_mb__before_atomic();
+               smp_mb__after_atomic(); /* flush memory to make sure DOWN is seen by service task */
                hclge_flush_link_update(hdev);
        }
 }

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c b/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c
index 9afb44d738c4e7e2a74695268163ec669be2cdb9..a41e04796b0b62f9b5eb9829dcaeca0a3144c768 100644 (file)
--- a/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c
@@ -2722,8 +2722,7 @@ static void hclgevf_set_timer_task(struct hnae3_handle *handle, bool enable)
        } else {
                set_bit(HCLGEVF_STATE_DOWN, &hdev->state);
 
-               /* flush memory to make sure DOWN is seen by service task */
-               smp_mb__before_atomic();
+               smp_mb__after_atomic(); /* flush memory to make sure DOWN is seen by service task */
                hclgevf_flush_link_update(hdev);
        }
 }