This patch adds more detailed comments when we call the
memory barrier function, such as rmb, wmb and mb. Three
mb() callers are deleted since they are unnecessary.
v3:
1. Subsitute rmb() with dma_rmb() according to Jason's comment,
since using dma_rmb() is enough.
Signed-off-by: Yixian Liu <liuyixian@xxxxxxxxxx>
Signed-off-by: Lijun Ou <oulijun@xxxxxxxxxx>
Signed-off-by: Wei Hu (Xavier) <xavier.huwei@xxxxxxxxxx>
Reviewed-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
---
drivers/infiniband/hw/hns/hns_roce_hw_v1.c | 22 ++++++++++++++++------
drivers/infiniband/hw/hns/hns_roce_hw_v2.c | 26 +++++++++++++-------------
2 files changed, 29 insertions(+), 19 deletions(-)
diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v1.c b/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
index 6100ace..47ef90b 100644
--- a/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
+++ b/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
@@ -3963,7 +3963,10 @@ static void set_eq_cons_index_v1(struct hns_roce_eq *eq, int req_not)
{
roce_raw_write((eq->cons_index & HNS_ROCE_V1_CONS_IDX_M) |
(req_not << eq->log_entries), eq->doorbell);
- /* Memory barrier */
+
+ /* Make sure we update the consumer index of EQ before
+ * accessing it later
+ */
mb();
}
@@ -4156,13 +4159,16 @@ static int hns_roce_v1_aeq_int(struct hns_roce_dev *hr_dev,
int event_type;
while ((aeqe = next_aeqe_sw_v1(eq))) {
+
+ /* Make sure we read the AEQ entry after we have checked the
+ * ownership bit
+ */
+ dma_rmb();
+
dev_dbg(dev, "aeqe = %p, aeqe->asyn.event_type = 0x%lx\n", aeqe,
roce_get_field(aeqe->asyn,
HNS_ROCE_AEQE_U32_4_EVENT_TYPE_M,
HNS_ROCE_AEQE_U32_4_EVENT_TYPE_S));
- /* Memory barrier */
- rmb();
-
event_type = roce_get_field(aeqe->asyn,
HNS_ROCE_AEQE_U32_4_EVENT_TYPE_M,
HNS_ROCE_AEQE_U32_4_EVENT_TYPE_S);
@@ -4260,8 +4266,12 @@ static int hns_roce_v1_ceq_int(struct hns_roce_dev *hr_dev,
u32 cqn;
while ((ceqe = next_ceqe_sw_v1(eq))) {
- /* Memory barrier */
- rmb();
+
+ /* Make sure we read CEQ entry after we have checked the
+ * ownership bit
+ */
+ dma_rmb();
+
cqn = roce_get_field(ceqe->comp,
HNS_ROCE_CEQE_CEQE_COMP_CQN_M,
HNS_ROCE_CEQE_CEQE_COMP_CQN_S);
diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
index 04281d0..4b300c8 100644
--- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
+++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
@@ -3200,7 +3200,9 @@ static void set_eq_cons_index_v2(struct hns_roce_eq *eq)
hns_roce_write64_k(doorbell, eq->doorbell);
- /* Memory barrier */
+ /* Make sure we update the consumer index of EQ before
+ * accessing it later
+ */
mb();
}
@@ -3384,8 +3386,11 @@ static int hns_roce_v2_aeq_int(struct hns_roce_dev *hr_dev,
int event_type;
while ((aeqe = next_aeqe_sw_v2(eq))) {
- /* Memory barrier */
- rmb();
+
+ /* Make sure we read AEQ entry after we have checked the
+ * ownership bit
+ */
+ dma_rmb();
event_type = roce_get_field(aeqe->asyn,
HNS_ROCE_V2_AEQE_EVENT_TYPE_M,
@@ -3500,8 +3505,11 @@ static int hns_roce_v2_ceq_int(struct hns_roce_dev *hr_dev,
while ((ceqe = next_ceqe_sw_v2(eq))) {
- /* Memory barrier */
- rmb();
+ /* Make sure we read CEQ entry after we have checked the
+ * ownership bit
+ */
+ dma_rmb();
+
cqn = roce_get_field(ceqe->comp,
HNS_ROCE_V2_CEQE_COMP_CQN_M,
HNS_ROCE_V2_CEQE_COMP_CQN_S);
@@ -3556,9 +3564,6 @@ static irqreturn_t hns_roce_v2_msix_interrupt_abn(int irq, void *dev_id)
roce_set_bit(int_st, HNS_ROCE_V2_VF_INT_ST_AEQ_OVERFLOW_S, 1);
roce_write(hr_dev, ROCEE_VF_ABN_INT_ST_REG, int_st);
- /* Memory barrier */
- mb();
-
roce_set_bit(int_en, HNS_ROCE_V2_VF_ABN_INT_EN_S, 1);
roce_write(hr_dev, ROCEE_VF_ABN_INT_EN_REG, int_en);
@@ -3569,9 +3574,6 @@ static irqreturn_t hns_roce_v2_msix_interrupt_abn(int irq, void *dev_id)
roce_set_bit(int_st, HNS_ROCE_V2_VF_INT_ST_BUS_ERR_S, 1);
roce_write(hr_dev, ROCEE_VF_ABN_INT_ST_REG, int_st);
- /* Memory barrier */
- mb();
-
roce_set_bit(int_en, HNS_ROCE_V2_VF_ABN_INT_EN_S, 1);
roce_write(hr_dev, ROCEE_VF_ABN_INT_EN_REG, int_en);
@@ -3582,8 +3584,6 @@ static irqreturn_t hns_roce_v2_msix_interrupt_abn(int irq, void *dev_id)
roce_set_bit(int_st, HNS_ROCE_V2_VF_INT_ST_OTHER_ERR_S, 1);
roce_write(hr_dev, ROCEE_VF_ABN_INT_ST_REG, int_st);
- /* Memory barrier */
- mb();
roce_set_bit(int_en, HNS_ROCE_V2_VF_ABN_INT_EN_S, 1);
roce_write(hr_dev, ROCEE_VF_ABN_INT_EN_REG, int_en);
--
1.9.1
--
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