RDMA/hns: Modify the usage of cmd_sn in hip08

The cmd_sn field of CQ doorbell inits for 0. It should be
increment on each first db rung after a completion Event.
if the cmd_sn of notify doorbell Adjacent two times is the
same, the hardware will distinguish it for the same notify
request and update its type according to the priority level
of next event and solicited event.
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/hns/hns_roce_cq.c

@@ -156,6 +156,7 @@ static int hns_roce_cq_alloc(struct hns_roce_dev *hr_dev, int nent,
 	}
 
 	hr_cq->cons_index = 0;
+	hr_cq->arm_sn = 1;
 	hr_cq->uar = hr_uar;
 
 	atomic_set(&hr_cq->refcount, 1);
@@ -456,6 +457,7 @@ void hns_roce_cq_completion(struct hns_roce_dev *hr_dev, u32 cqn)
 		return;
 	}
 
+	++cq->arm_sn;
 	cq->comp(cq);
 }
 

drivers/infiniband/hw/hns/hns_roce_device.h

@@ -347,6 +347,7 @@ struct hns_roce_cq {
 	u32				cons_index;
 	void __iomem			*cq_db_l;
 	u16				*tptr_addr;
+	int				arm_sn;
 	unsigned long			cqn;
 	u32				vector;
 	atomic_t			refcount;

drivers/infiniband/hw/hns/hns_roce_hw_v2.c

@@ -1440,7 +1440,7 @@ static int hns_roce_v2_req_notify_cq(struct ib_cq *ibcq,
 		       V2_CQ_DB_PARAMETER_CONS_IDX_S,
 		       hr_cq->cons_index & ((hr_cq->cq_depth << 1) - 1));
 	roce_set_field(doorbell[1], V2_CQ_DB_PARAMETER_CMD_SN_M,
-		       V2_CQ_DB_PARAMETER_CMD_SN_S, 1);
+		       V2_CQ_DB_PARAMETER_CMD_SN_S, hr_cq->arm_sn & 0x3);
 	roce_set_bit(doorbell[1], V2_CQ_DB_PARAMETER_NOTIFY_S,
 		     notification_flag);