[PATCH net 4/7] net: hns3: use appropriate barrier function after setting a bit value

Jijie Shao
2024-04-22T13:49:54Z

From: Peiyang Wang <wangpeiyang1@huawei.com>

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>
---
drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c | 3 +--
drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c | 3 +--
2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
index a068cd745eb4..6eda73f1e6ad 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
@@ -7954,8 +7954,7 @@ 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 b57111252d07..08db8e84be4e 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c
@@ -2181,8 +2181,7 @@ 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);
}
}
--
2.30.0