RDMA/hns: Clear remaining unused sges when post_recv

The HIP09 requires the driver to clear the unused data segments in wqe
buffer to make the hns ROCEE stop reading the remaining invalid sges for
RQ.

Link: https://lore.kernel.org/r/1611997090-48820-11-git-send-email-liweihang@huawei.com
Signed-off-by: Xi Wang <wangxi11@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
index 1f70422..7eba9b5 100644 (file)
--- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
+++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
@@ -729,28 +729,42 @@ static int check_recv_valid(struct hns_roce_dev *hr_dev,
        return 0;
 }
 
-static void fill_rq_wqe(struct hns_roce_qp *hr_qp, const struct ib_recv_wr *wr,
-                       u32 wqe_idx)
+static void fill_recv_sge_to_wqe(const struct ib_recv_wr *wr, void *wqe,
+                                u32 max_sge, bool rsv)
 {
-       struct hns_roce_v2_wqe_data_seg *dseg;
-       struct hns_roce_rinl_sge *sge_list;
-       void *wqe = NULL;
-       int i;
+       struct hns_roce_v2_wqe_data_seg *dseg = wqe;
+       u32 i, cnt;
 
-       wqe = hns_roce_get_recv_wqe(hr_qp, wqe_idx);
-       dseg = (struct hns_roce_v2_wqe_data_seg *)wqe;
-       for (i = 0; i < wr->num_sge; i++) {
+       for (i = 0, cnt = 0; i < wr->num_sge; i++) {
+               /* Skip zero-length sge */
                if (!wr->sg_list[i].length)
                        continue;
-               set_data_seg_v2(dseg, wr->sg_list + i);
-               dseg++;
+               set_data_seg_v2(dseg + cnt, wr->sg_list + i);
+               cnt++;
        }
 
-       if (hr_qp->rq.rsv_sge) {
-               dseg->lkey = cpu_to_le32(HNS_ROCE_INVALID_LKEY);
-               dseg->addr = 0;
-               dseg->len = cpu_to_le32(HNS_ROCE_INVALID_SGE_LENGTH);
+       /* Fill a reserved sge to make hw stop reading remaining segments */
+       if (rsv) {
+               dseg[cnt].lkey = cpu_to_le32(HNS_ROCE_INVALID_LKEY);
+               dseg[cnt].addr = 0;
+               dseg[cnt].len = cpu_to_le32(HNS_ROCE_INVALID_SGE_LENGTH);
+       } else {
+               /* Clear remaining segments to make ROCEE ignore sges */
+               if (cnt < max_sge)
+                       memset(dseg + cnt, 0,
+                              (max_sge - cnt) * HNS_ROCE_SGE_SIZE);
        }
+}
+
+static void fill_rq_wqe(struct hns_roce_qp *hr_qp, const struct ib_recv_wr *wr,
+                       u32 wqe_idx, u32 max_sge)
+{
+       struct hns_roce_rinl_sge *sge_list;
+       void *wqe = NULL;
+       u32 i;
+
+       wqe = hns_roce_get_recv_wqe(hr_qp, wqe_idx);
+       fill_recv_sge_to_wqe(wr, wqe, max_sge, hr_qp->rq.rsv_sge);
 
        /* rq support inline data */
        if (hr_qp->rq_inl_buf.wqe_cnt) {
@@ -801,8 +815,7 @@ static int hns_roce_v2_post_recv(struct ib_qp *ibqp,
                }
 
                wqe_idx = (hr_qp->rq.head + nreq) & (hr_qp->rq.wqe_cnt - 1);
-               fill_rq_wqe(hr_qp, wr, wqe_idx);
-
+               fill_rq_wqe(hr_qp, wr, wqe_idx, max_sge);
                hr_qp->rq.wrid[wqe_idx] = wr->wr_id;
        }
 
@@ -834,18 +847,18 @@ out:
        return ret;
 }
 
-static void *get_srq_wqe(struct hns_roce_srq *srq, int n)
+static void *get_srq_wqe_buf(struct hns_roce_srq *srq, u32 n)
 {
        return hns_roce_buf_offset(srq->buf_mtr.kmem, n << srq->wqe_shift);
 }
 
-static void *get_idx_buf(struct hns_roce_idx_que *idx_que, unsigned int n)
+static void *get_idx_buf(struct hns_roce_idx_que *idx_que, u32 n)
 {
        return hns_roce_buf_offset(idx_que->mtr.kmem,
                                   n << idx_que->entry_shift);
 }
 
-static void hns_roce_free_srq_wqe(struct hns_roce_srq *srq, int wqe_index)
+static void hns_roce_free_srq_wqe(struct hns_roce_srq *srq, u32 wqe_index)
 {
        /* always called with interrupts disabled. */
        spin_lock(&srq->lock);
@@ -856,7 +869,7 @@ static void hns_roce_free_srq_wqe(struct hns_roce_srq *srq, int wqe_index)
        spin_unlock(&srq->lock);
 }
 
-int hns_roce_srqwq_overflow(struct hns_roce_srq *srq, int nreq)
+int hns_roce_srqwq_overflow(struct hns_roce_srq *srq, u32 nreq)
 {
        struct hns_roce_idx_que *idx_que = &srq->idx_que;
        unsigned int cur;
@@ -865,19 +878,18 @@ int hns_roce_srqwq_overflow(struct hns_roce_srq *srq, int nreq)
        return cur + nreq >= srq->wqe_cnt;
 }
 
-static int find_empty_entry(struct hns_roce_idx_que *idx_que,
-                           unsigned long size)
+static int get_srq_wqe_idx(struct hns_roce_srq *srq, u32 *wqe_idx)
 {
-       int wqe_idx;
+       struct hns_roce_idx_que *idx_que = &srq->idx_que;
+       u32 pos;
 
-       if (unlikely(bitmap_full(idx_que->bitmap, size)))
+       pos = find_first_zero_bit(idx_que->bitmap, srq->wqe_cnt);
+       if (unlikely(pos == srq->wqe_cnt))
                return -ENOSPC;
 
-       wqe_idx = find_first_zero_bit(idx_que->bitmap, size);
-
-       bitmap_set(idx_que->bitmap, wqe_idx, 1);
-
-       return wqe_idx;
+       bitmap_set(idx_que->bitmap, pos, 1);
+       *wqe_idx = pos;
+       return 0;
 }
 
 static int hns_roce_v2_post_srq_recv(struct ib_srq *ibsrq,
@@ -886,17 +898,12 @@ static int hns_roce_v2_post_srq_recv(struct ib_srq *ibsrq,
 {
        struct hns_roce_dev *hr_dev = to_hr_dev(ibsrq->device);
        struct hns_roce_srq *srq = to_hr_srq(ibsrq);
-       struct hns_roce_v2_wqe_data_seg *dseg;
+       u32 wqe_idx, ind, nreq, max_sge;
        struct hns_roce_v2_db srq_db;
        unsigned long flags;
-       unsigned int ind;
        __le32 *srq_idx;
        int ret = 0;
-       int wqe_idx;
-       u32 max_sge;
        void *wqe;
-       int nreq;
-       int i;
 
        spin_lock_irqsave(&srq->lock, flags);
 
@@ -919,26 +926,14 @@ static int hns_roce_v2_post_srq_recv(struct ib_srq *ibsrq,
                        break;
                }
 
-               wqe_idx = find_empty_entry(&srq->idx_que, srq->wqe_cnt);
-               if (unlikely(wqe_idx < 0)) {
-                       ret = -ENOMEM;
+               ret = get_srq_wqe_idx(srq, &wqe_idx);
+               if (unlikely(ret)) {
                        *bad_wr = wr;
                        break;
                }
 
-               wqe = get_srq_wqe(srq, wqe_idx);
-               dseg = (struct hns_roce_v2_wqe_data_seg *)wqe;
-
-               for (i = 0; i < wr->num_sge; ++i) {
-                       set_data_seg_v2(dseg, wr->sg_list + i);
-                       dseg++;
-               }
-
-               if (srq->rsv_sge) {
-                       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;
-               }
+               wqe = get_srq_wqe_buf(srq, wqe_idx);
+               fill_recv_sge_to_wqe(wr, wqe, max_sge, srq->rsv_sge);
 
                srq_idx = get_idx_buf(&srq->idx_que, ind);
                *srq_idx = cpu_to_le32(wqe_idx);