IB/mlx5: Break up wqe handling into begin & finish routines

As a preliminary step for signature feature which will require posting
multiple (3) WQEs for a single WR, we break post_send routine WQE
indexing into begin and finish routines.

This patch does not change any functionality.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 61 insertions, 36 deletions

diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c
index 01999f3744fb..a029009323ec 100644
--- a/drivers/infiniband/hw/mlx5/qp.c
+++ b/drivers/infiniband/hw/mlx5/qp.c
@@ -2047,6 +2047,59 @@ static u8 get_fence(u8 fence, struct ib_send_wr *wr)
         }
 }
 
+static int begin_wqe(struct mlx5_ib_qp *qp, void **seg,
+                     struct mlx5_wqe_ctrl_seg **ctrl,
+                     struct ib_send_wr *wr, int *idx,
+                     int *size, int nreq)
+{
+        int err = 0;
+
+        if (unlikely(mlx5_wq_overflow(&qp->sq, nreq, qp->ibqp.send_cq))) {
+                err = -ENOMEM;
+                return err;
+        }
+
+        *idx = qp->sq.cur_post & (qp->sq.wqe_cnt - 1);
+        *seg = mlx5_get_send_wqe(qp, *idx);
+        *ctrl = *seg;
+        *(uint32_t *)(*seg + 8) = 0;
+        (*ctrl)->imm = send_ieth(wr);
+        (*ctrl)->fm_ce_se = qp->sq_signal_bits |
+                (wr->send_flags & IB_SEND_SIGNALED ?
+                 MLX5_WQE_CTRL_CQ_UPDATE : 0) |
+                (wr->send_flags & IB_SEND_SOLICITED ?
+                 MLX5_WQE_CTRL_SOLICITED : 0);
+
+        *seg += sizeof(**ctrl);
+        *size = sizeof(**ctrl) / 16;
+
+        return err;
+}
+
+static void finish_wqe(struct mlx5_ib_qp *qp,
+                       struct mlx5_wqe_ctrl_seg *ctrl,
+                       u8 size, unsigned idx, u64 wr_id,
+                       int nreq, u8 fence, u8 next_fence,
+                       u32 mlx5_opcode)
+{
+        u8 opmod = 0;
+
+        ctrl->opmod_idx_opcode = cpu_to_be32(((u32)(qp->sq.cur_post) << 8) |
+                                             mlx5_opcode | ((u32)opmod << 24));
+        ctrl->qpn_ds = cpu_to_be32(size | (qp->mqp.qpn << 8));
+        ctrl->fm_ce_se |= fence;
+        qp->fm_cache = next_fence;
+        if (unlikely(qp->wq_sig))
+                ctrl->signature = wq_sig(ctrl);
+
+        qp->sq.wrid[idx] = wr_id;
+        qp->sq.w_list[idx].opcode = mlx5_opcode;
+        qp->sq.wqe_head[idx] = qp->sq.head + nreq;
+        qp->sq.cur_post += DIV_ROUND_UP(size * 16, MLX5_SEND_WQE_BB);
+        qp->sq.w_list[idx].next = qp->sq.cur_post;
+}
+
+
 int mlx5_ib_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
                       struct ib_send_wr **bad_wr)
 {
@@ -2060,7 +2113,6 @@ int mlx5_ib_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
         int uninitialized_var(size);
         void *qend = qp->sq.qend;
         unsigned long flags;
-        u32 mlx5_opcode;
         unsigned idx;
         int err = 0;
         int inl = 0;
@@ -2069,7 +2121,6 @@ int mlx5_ib_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
         int nreq;
         int i;
         u8 next_fence = 0;
-        u8 opmod = 0;
         u8 fence;
 
         spin_lock_irqsave(&qp->sq.lock, flags);
@@ -2082,36 +2133,23 @@ int mlx5_ib_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
                         goto out;
                 }
 
-                if (unlikely(mlx5_wq_overflow(&qp->sq, nreq, qp->ibqp.send_cq))) {
+                fence = qp->fm_cache;
+                num_sge = wr->num_sge;
+                if (unlikely(num_sge > qp->sq.max_gs)) {
                         mlx5_ib_warn(dev, "\n");
                         err = -ENOMEM;
                         *bad_wr = wr;
                         goto out;
                 }
 
-                fence = qp->fm_cache;
-                num_sge = wr->num_sge;
-                if (unlikely(num_sge > qp->sq.max_gs)) {
+                err = begin_wqe(qp, &seg, &ctrl, wr, &idx, &size, nreq);
+                if (err) {
                         mlx5_ib_warn(dev, "\n");
                         err = -ENOMEM;
                         *bad_wr = wr;
                         goto out;
                 }
 
-                idx = qp->sq.cur_post & (qp->sq.wqe_cnt - 1);
-                seg = mlx5_get_send_wqe(qp, idx);
-                ctrl = seg;
-                *(uint32_t *)(seg + 8) = 0;
-                ctrl->imm = send_ieth(wr);
-                ctrl->fm_ce_se = qp->sq_signal_bits |
-                        (wr->send_flags & IB_SEND_SIGNALED ?
-                         MLX5_WQE_CTRL_CQ_UPDATE : 0) |
-                        (wr->send_flags & IB_SEND_SOLICITED ?
-                         MLX5_WQE_CTRL_SOLICITED : 0);
-
-                seg += sizeof(*ctrl);
-                size = sizeof(*ctrl) / 16;
-
                 switch (ibqp->qp_type) {
                 case IB_QPT_XRC_INI:
                         xrc = seg;
@@ -2244,22 +2282,9 @@ int mlx5_ib_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
                         }
                 }
 
-                mlx5_opcode = mlx5_ib_opcode[wr->opcode];
-                ctrl->opmod_idx_opcode = cpu_to_be32(((u32)(qp->sq.cur_post) << 8)      |
-                                                     mlx5_opcode                        |
-                                                     ((u32)opmod << 24));
-                ctrl->qpn_ds = cpu_to_be32(size | (qp->mqp.qpn << 8));
-                ctrl->fm_ce_se |= get_fence(fence, wr);
-                qp->fm_cache = next_fence;
-                if (unlikely(qp->wq_sig))
-                        ctrl->signature = wq_sig(ctrl);
-
-                qp->sq.wrid[idx] = wr->wr_id;
-                qp->sq.w_list[idx].opcode = mlx5_opcode;
-                qp->sq.wqe_head[idx] = qp->sq.head + nreq;
-                qp->sq.cur_post += DIV_ROUND_UP(size * 16, MLX5_SEND_WQE_BB);
-                qp->sq.w_list[idx].next = qp->sq.cur_post;
-
+                finish_wqe(qp, ctrl, size, idx, wr->wr_id, nreq,
+                           get_fence(fence, wr), next_fence,
+                           mlx5_ib_opcode[wr->opcode]);
                 if (0)
                         dump_wqe(qp, idx, size);
         }