RDMA/hns: reserve one sge in order to avoid local length error

driver inclusion
category: bugfix
bugzilla: NA
CVE: NA

When rq/srq sge length is smaller than sq sge length, local length error
would occur. Then, for rq wqe and srq wqe, one reserved sge pointing to
a reserved mr is used to avoid this error.

Feature or Bugfix: Bugfix
Signed-off-by: NWeihang Li <liweihang@hisilicon.com>
Reviewed-by: Nliuyixian <liuyixian@huawei.com>
Reviewed-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/infiniband/hw/hns/hns_roce_device.h

@@ -73,6 +73,8 @@
 
 #define HNS_ROCE_WORKQ_NAME_LEN			32
 
+#define HNS_ROCE_RESERVED_SGE			1
+
 #define HNS_ROCE_MAX_IRQ_NUM			128
 
 #define HNS_ROCE_SGE_IN_WQE			2

drivers/infiniband/hw/hns/hns_roce_hw_v2.c

@@ -769,8 +769,8 @@ static int hns_roce_v2_post_recv(struct ib_qp *ibqp, struct ib_recv_wr *wr,
 			goto out;
 		}
 
-		if (unlikely(wr->num_sge > hr_qp->rq.max_gs)) {
-			dev_err(dev, "rq:num_sge=%d > qp->rq.max_gs=%d\n",
+		if (unlikely(wr->num_sge >= hr_qp->rq.max_gs)) {
+			dev_err(dev, "rq:num_sge=%d >= qp->rq.max_gs=%d\n",
 				wr->num_sge, hr_qp->rq.max_gs);
 			ret = -EINVAL;
 			*bad_wr = wr;
@@ -786,9 +786,10 @@ static int hns_roce_v2_post_recv(struct ib_qp *ibqp, struct ib_recv_wr *wr,
 			dseg++;
 		}
 
-		if (i < hr_qp->rq.max_gs) {
+		if (wr->num_sge < hr_qp->rq.max_gs) {
 			dseg->lkey = cpu_to_le32(HNS_ROCE_INVALID_LKEY);
 			dseg->addr = 0;
+			dseg->len = HNS_ROCE_INVALID_SGE_LENGTH;
 		}
 
 		/* rq support inline data */
@@ -6794,7 +6795,7 @@ static int hns_roce_v2_post_srq_recv(struct ib_srq *ibsrq,
 
 	ind = srq->head & (srq->max - 1);
 	for (nreq = 0; wr; ++nreq, wr = wr->next) {
-		if (unlikely(wr->num_sge > srq->max_gs)) {
+		if (unlikely(wr->num_sge >= srq->max_gs)) {
 			dev_err(hr_dev->dev,
 				"srq(0x%lx) wr sge num(%d) exceed the max num %d.\n",
 				srq->srqn, wr->num_sge, srq->max_gs);
@@ -6822,9 +6823,9 @@ static int hns_roce_v2_post_srq_recv(struct ib_srq *ibsrq,
 			dseg[i].addr	= cpu_to_le64(wr->sg_list[i].addr);
 		}
 
-		if (i < srq->max_gs) {
-			dseg[i].len	= 0;
-			dseg[i].lkey	= cpu_to_le32(0x100);
+		if (wr->num_sge < srq->max_gs) {
+			dseg[i].len = cpu_to_le32(HNS_ROCE_INVALID_SGE_LENGTH);
+			dseg[i].lkey = cpu_to_le32(HNS_ROCE_INVALID_LKEY);
 			dseg[i].addr = 0;
 		}
 

drivers/infiniband/hw/hns/hns_roce_hw_v2.h

@@ -53,15 +53,16 @@
 #define HNS_ROCE_V2_MAX_WQE_NUM			0x8000
 #define	HNS_ROCE_V2_MAX_SRQ			0x100000
 #define HNS_ROCE_V2_MAX_SRQ_WR			0x8000
-#define HNS_ROCE_V2_MAX_SRQ_SGE			0x100
+#define HNS_ROCE_V2_MAX_SRQ_SGE			0xff
 #define HNS_ROCE_V2_MAX_CQ_NUM			0x100000
 #define HNS_ROCE_V2_MAX_CQC_TIMER_NUM		0x100
 #define HNS_ROCE_V2_MAX_SRQ_NUM			0x100000
 #define HNS_ROCE_V2_MAX_CQE_NUM			0x400000
 #define HNS_ROCE_V2_MAX_SRQWQE_NUM		0x8000
-#define HNS_ROCE_V2_MAX_RQ_SGE_NUM		0x100
+/* reserve one sge to circumvent a hardware issue */
+#define HNS_ROCE_V2_MAX_RQ_SGE_NUM		0xff
 #define HNS_ROCE_V2_MAX_SQ_SGE_NUM		0xff
-#define HNS_ROCE_V2_MAX_SRQ_SGE_NUM		0x100
+#define HNS_ROCE_V2_MAX_SRQ_SGE_NUM		0xff
 #define HNS_ROCE_V2_MAX_EXTEND_SGE_NUM		0x200000
 #define HNS_ROCE_V2_MAX_SQ_INLINE		0x20
 #define HNS_ROCE_V2_UAR_NUM			256
@@ -97,7 +98,8 @@
 #define HNS_ROCE_V2_CQC_TIMER_ENTRY_SZ		4096
 #define HNS_ROCE_V2_PAGE_SIZE_SUPPORTED		0xFFFFF000
 #define HNS_ROCE_V2_MAX_INNER_MTPT_NUM		2
-#define HNS_ROCE_INVALID_LKEY			0x100
+#define HNS_ROCE_INVALID_LKEY			0x0
+#define HNS_ROCE_INVALID_SGE_LENGTH		0x80000000
 #define HNS_ROCE_CMQ_TX_TIMEOUT			30000
 #define HNS_ROCE_V2_UC_RC_SGE_NUM_IN_WQE	2
 #define HNS_ROCE_V2_RSV_QPS			8

drivers/infiniband/hw/hns/hns_roce_qp.c

@@ -382,7 +382,8 @@ static int hns_roce_set_rq_size(struct hns_roce_dev *hr_dev,
 		}
 
 		max_cnt = max(1U, cap->max_recv_sge);
-		hr_qp->rq.max_gs = roundup_pow_of_two(max_cnt);
+		hr_qp->rq.max_gs = roundup_pow_of_two(max_cnt +
+						      HNS_ROCE_RESERVED_SGE);
 		if (hr_dev->caps.max_rq_sg <= HNS_ROCE_MAX_SGE_NUM)
 			hr_qp->rq.wqe_shift =
 					ilog2(hr_dev->caps.max_rq_desc_sz);
@@ -393,7 +394,7 @@ static int hns_roce_set_rq_size(struct hns_roce_dev *hr_dev,
 	}
 
 	cap->max_recv_wr = hr_qp->rq.max_post = hr_qp->rq.wqe_cnt;
-	cap->max_recv_sge = hr_qp->rq.max_gs;
+	cap->max_recv_sge = hr_qp->rq.max_gs - HNS_ROCE_RESERVED_SGE;
 
 	return 0;
 }

drivers/infiniband/hw/hns/hns_roce_srq.c

@@ -450,7 +450,7 @@ struct ib_srq *hns_roce_create_srq(struct ib_pd *pd,
 	spin_lock_init(&srq->lock);
 
 	srq->max = roundup_pow_of_two(srq_init_attr->attr.max_wr + 1);
-	srq->max_gs = srq_init_attr->attr.max_sge;
+	srq->max_gs = srq_init_attr->attr.max_sge + HNS_ROCE_RESERVED_SGE;
 
 	srq_desc_size = max(HNS_ROCE_SGE_SIZE, HNS_ROCE_SGE_SIZE * srq->max_gs);