IB: split struct ib_send_wr

This patch split up struct ib_send_wr so that all non-trivial verbs
use their own structure which embedds struct ib_send_wr.  This dramaticly
shrinks the size of a WR for most common operations:

sizeof(struct ib_send_wr) (old):	96

sizeof(struct ib_send_wr):		48
sizeof(struct ib_rdma_wr):		64
sizeof(struct ib_atomic_wr):		96
sizeof(struct ib_ud_wr):		88
sizeof(struct ib_fast_reg_wr):		88
sizeof(struct ib_bind_mw_wr):		96
sizeof(struct ib_sig_handover_wr):	80

And with Sagi's pending MR rework the fast registration WR will also be
down to a reasonable size:

sizeof(struct ib_fastreg_wr):		64

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> [srp, srpt]
Reviewed-by: Chuck Lever <chuck.lever@oracle.com> [sunrpc]
Tested-by: Haggai Eran <haggaie@mellanox.com>
Tested-by: Sagi Grimberg <sagig@mellanox.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>

3 files changed, 42 insertions, 42 deletions

diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.h b/drivers/infiniband/ulp/iser/iscsi_iser.h
index a5edd6ede692..2fab519dbd86 100644
--- a/drivers/infiniband/ulp/iser/iscsi_iser.h
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.h
@@ -300,7 +300,11 @@ struct iser_tx_desc {
 	int                          num_sge;
 	bool			     mapped;
 	u8                           wr_idx;
-	struct ib_send_wr            wrs[ISER_MAX_WRS];
+	union iser_wr {
+		struct ib_send_wr		send;
+		struct ib_fast_reg_wr		fast_reg;
+		struct ib_sig_handover_wr	sig;
+	} wrs[ISER_MAX_WRS];
 	struct iser_mem_reg          data_reg;
 	struct iser_mem_reg          prot_reg;
 	struct ib_sig_attrs          sig_attrs;
@@ -712,11 +716,11 @@ iser_reg_desc_put_fmr(struct ib_conn *ib_conn,
 static inline struct ib_send_wr *
 iser_tx_next_wr(struct iser_tx_desc *tx_desc)
 {
-	struct ib_send_wr *cur_wr = &tx_desc->wrs[tx_desc->wr_idx];
+	struct ib_send_wr *cur_wr = &tx_desc->wrs[tx_desc->wr_idx].send;
 	struct ib_send_wr *last_wr;
 
 	if (tx_desc->wr_idx) {
-		last_wr = &tx_desc->wrs[tx_desc->wr_idx - 1];
+		last_wr = &tx_desc->wrs[tx_desc->wr_idx - 1].send;
 		last_wr->next = cur_wr;
 	}
 	tx_desc->wr_idx++;
diff --git a/drivers/infiniband/ulp/iser/iser_memory.c b/drivers/infiniband/ulp/iser/iser_memory.c
index 4c46d67d37a1..f45e6a352173 100644
--- a/drivers/infiniband/ulp/iser/iser_memory.c
+++ b/drivers/infiniband/ulp/iser/iser_memory.c
@@ -683,7 +683,7 @@ iser_reg_sig_mr(struct iscsi_iser_task *iser_task,
 {
 	struct iser_tx_desc *tx_desc = &iser_task->desc;
 	struct ib_sig_attrs *sig_attrs = &tx_desc->sig_attrs;
-	struct ib_send_wr *wr;
+	struct ib_sig_handover_wr *wr;
 	int ret;
 
 	memset(sig_attrs, 0, sizeof(*sig_attrs));
@@ -693,26 +693,24 @@ iser_reg_sig_mr(struct iscsi_iser_task *iser_task,
 
 	iser_set_prot_checks(iser_task->sc, &sig_attrs->check_mask);
 
-	if (!pi_ctx->sig_mr_valid) {
-		wr = iser_tx_next_wr(tx_desc);
-		iser_inv_rkey(wr, pi_ctx->sig_mr);
-	}
-
-	wr = iser_tx_next_wr(tx_desc);
-	wr->opcode = IB_WR_REG_SIG_MR;
-	wr->wr_id = ISER_FASTREG_LI_WRID;
-	wr->sg_list = &data_reg->sge;
-	wr->num_sge = 1;
-	wr->send_flags = 0;
-	wr->wr.sig_handover.sig_attrs = sig_attrs;
-	wr->wr.sig_handover.sig_mr = pi_ctx->sig_mr;
+	if (!pi_ctx->sig_mr_valid)
+		iser_inv_rkey(iser_tx_next_wr(tx_desc), pi_ctx->sig_mr);
+
+	wr = sig_handover_wr(iser_tx_next_wr(tx_desc));
+	wr->wr.opcode = IB_WR_REG_SIG_MR;
+	wr->wr.wr_id = ISER_FASTREG_LI_WRID;
+	wr->wr.sg_list = &data_reg->sge;
+	wr->wr.num_sge = 1;
+	wr->wr.send_flags = 0;
+	wr->sig_attrs = sig_attrs;
+	wr->sig_mr = pi_ctx->sig_mr;
 	if (scsi_prot_sg_count(iser_task->sc))
-		wr->wr.sig_handover.prot = &prot_reg->sge;
+		wr->prot = &prot_reg->sge;
 	else
-		wr->wr.sig_handover.prot = NULL;
-	wr->wr.sig_handover.access_flags = IB_ACCESS_LOCAL_WRITE |
-					   IB_ACCESS_REMOTE_READ |
-					   IB_ACCESS_REMOTE_WRITE;
+		wr->prot = NULL;
+	wr->access_flags = IB_ACCESS_LOCAL_WRITE |
+			   IB_ACCESS_REMOTE_READ |
+			   IB_ACCESS_REMOTE_WRITE;
 	pi_ctx->sig_mr_valid = 0;
 
 	sig_reg->sge.lkey = pi_ctx->sig_mr->lkey;
@@ -737,7 +735,7 @@ static int iser_fast_reg_mr(struct iscsi_iser_task *iser_task,
 	struct ib_mr *mr = rsc->mr;
 	struct ib_fast_reg_page_list *frpl = rsc->frpl;
 	struct iser_tx_desc *tx_desc = &iser_task->desc;
-	struct ib_send_wr *wr;
+	struct ib_fast_reg_wr *wr;
 	int offset, size, plen;
 
 	plen = iser_sg_to_page_vec(mem, device->ib_device, frpl->page_list,
@@ -747,24 +745,22 @@ static int iser_fast_reg_mr(struct iscsi_iser_task *iser_task,
 		return -EINVAL;
 	}
 
-	if (!rsc->mr_valid) {
-		wr = iser_tx_next_wr(tx_desc);
-		iser_inv_rkey(wr, mr);
-	}
-
-	wr = iser_tx_next_wr(tx_desc);
-	wr->opcode = IB_WR_FAST_REG_MR;
-	wr->wr_id = ISER_FASTREG_LI_WRID;
-	wr->send_flags = 0;
-	wr->wr.fast_reg.iova_start = frpl->page_list[0] + offset;
-	wr->wr.fast_reg.page_list = frpl;
-	wr->wr.fast_reg.page_list_len = plen;
-	wr->wr.fast_reg.page_shift = SHIFT_4K;
-	wr->wr.fast_reg.length = size;
-	wr->wr.fast_reg.rkey = mr->rkey;
-	wr->wr.fast_reg.access_flags = (IB_ACCESS_LOCAL_WRITE  |
-					IB_ACCESS_REMOTE_WRITE |
-					IB_ACCESS_REMOTE_READ);
+	if (!rsc->mr_valid)
+		iser_inv_rkey(iser_tx_next_wr(tx_desc), mr);
+
+	wr = fast_reg_wr(iser_tx_next_wr(tx_desc));
+	wr->wr.opcode = IB_WR_FAST_REG_MR;
+	wr->wr.wr_id = ISER_FASTREG_LI_WRID;
+	wr->wr.send_flags = 0;
+	wr->iova_start = frpl->page_list[0] + offset;
+	wr->page_list = frpl;
+	wr->page_list_len = plen;
+	wr->page_shift = SHIFT_4K;
+	wr->length = size;
+	wr->rkey = mr->rkey;
+	wr->access_flags = (IB_ACCESS_LOCAL_WRITE  |
+			    IB_ACCESS_REMOTE_WRITE |
+			    IB_ACCESS_REMOTE_READ);
 	rsc->mr_valid = 0;
 
 	reg->sge.lkey = mr->lkey;
diff --git a/drivers/infiniband/ulp/iser/iser_verbs.c b/drivers/infiniband/ulp/iser/iser_verbs.c
index 85132d867bc8..b26022e30af1 100644
--- a/drivers/infiniband/ulp/iser/iser_verbs.c
+++ b/drivers/infiniband/ulp/iser/iser_verbs.c
@@ -1135,7 +1135,7 @@ int iser_post_send(struct ib_conn *ib_conn, struct iser_tx_desc *tx_desc,
 	wr->opcode = IB_WR_SEND;
 	wr->send_flags = signal ? IB_SEND_SIGNALED : 0;
 
-	ib_ret = ib_post_send(ib_conn->qp, &tx_desc->wrs[0], &bad_wr);
+	ib_ret = ib_post_send(ib_conn->qp, &tx_desc->wrs[0].send, &bad_wr);
 	if (ib_ret)
 		iser_err("ib_post_send failed, ret:%d opcode:%d\n",
 			 ib_ret, bad_wr->opcode);