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>

1 files changed, 58 insertions, 55 deletions

diff --git a/net/rds/iw_send.c b/net/rds/iw_send.c
index 86152ec3b887..f6e23c515b44 100644
--- a/net/rds/iw_send.c
+++ b/net/rds/iw_send.c
@@ -137,13 +137,13 @@ void rds_iw_send_init_ring(struct rds_iw_connection *ic)
 		send->s_op = NULL;
 		send->s_mapping = NULL;
 
-		send->s_wr.next = NULL;
-		send->s_wr.wr_id = i;
-		send->s_wr.sg_list = send->s_sge;
-		send->s_wr.num_sge = 1;
-		send->s_wr.opcode = IB_WR_SEND;
-		send->s_wr.send_flags = 0;
-		send->s_wr.ex.imm_data = 0;
+		send->s_send_wr.next = NULL;
+		send->s_send_wr.wr_id = i;
+		send->s_send_wr.sg_list = send->s_sge;
+		send->s_send_wr.num_sge = 1;
+		send->s_send_wr.opcode = IB_WR_SEND;
+		send->s_send_wr.send_flags = 0;
+		send->s_send_wr.ex.imm_data = 0;
 
 		sge = rds_iw_data_sge(ic, send->s_sge);
 		sge->lkey = 0;
@@ -179,7 +179,7 @@ void rds_iw_send_clear_ring(struct rds_iw_connection *ic)
 		ib_dereg_mr(send->s_mr);
 		BUG_ON(!send->s_page_list);
 		ib_free_fast_reg_page_list(send->s_page_list);
-		if (send->s_wr.opcode == 0xdead)
+		if (send->s_send_wr.opcode == 0xdead)
 			continue;
 		if (send->s_rm)
 			rds_iw_send_unmap_rm(ic, send, IB_WC_WR_FLUSH_ERR);
@@ -247,7 +247,7 @@ void rds_iw_send_cq_comp_handler(struct ib_cq *cq, void *context)
 			send = &ic->i_sends[oldest];
 
 			/* In the error case, wc.opcode sometimes contains garbage */
-			switch (send->s_wr.opcode) {
+			switch (send->s_send_wr.opcode) {
 			case IB_WR_SEND:
 				if (send->s_rm)
 					rds_iw_send_unmap_rm(ic, send, wc.status);
@@ -262,12 +262,12 @@ void rds_iw_send_cq_comp_handler(struct ib_cq *cq, void *context)
 			default:
 				printk_ratelimited(KERN_NOTICE
 						"RDS/IW: %s: unexpected opcode 0x%x in WR!\n",
-						__func__, send->s_wr.opcode);
+						__func__, send->s_send_wr.opcode);
 				break;
 			}
 
-			send->s_wr.opcode = 0xdead;
-			send->s_wr.num_sge = 1;
+			send->s_send_wr.opcode = 0xdead;
+			send->s_send_wr.num_sge = 1;
 			if (time_after(jiffies, send->s_queued + HZ/2))
 				rds_iw_stats_inc(s_iw_tx_stalled);
 
@@ -455,10 +455,10 @@ rds_iw_xmit_populate_wr(struct rds_iw_connection *ic,
 
 	WARN_ON(pos != send - ic->i_sends);
 
-	send->s_wr.send_flags = send_flags;
-	send->s_wr.opcode = IB_WR_SEND;
-	send->s_wr.num_sge = 2;
-	send->s_wr.next = NULL;
+	send->s_send_wr.send_flags = send_flags;
+	send->s_send_wr.opcode = IB_WR_SEND;
+	send->s_send_wr.num_sge = 2;
+	send->s_send_wr.next = NULL;
 	send->s_queued = jiffies;
 	send->s_op = NULL;
 
@@ -472,7 +472,7 @@ rds_iw_xmit_populate_wr(struct rds_iw_connection *ic,
 	} else {
 		/* We're sending a packet with no payload. There is only
 		 * one SGE */
-		send->s_wr.num_sge = 1;
+		send->s_send_wr.num_sge = 1;
 		sge = &send->s_sge[0];
 	}
 
@@ -672,23 +672,23 @@ int rds_iw_xmit(struct rds_connection *conn, struct rds_message *rm,
 		 */
 		if (ic->i_unsignaled_wrs-- == 0) {
 			ic->i_unsignaled_wrs = rds_iw_sysctl_max_unsig_wrs;
-			send->s_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED;
+			send->s_send_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED;
 		}
 
 		ic->i_unsignaled_bytes -= len;
 		if (ic->i_unsignaled_bytes <= 0) {
 			ic->i_unsignaled_bytes = rds_iw_sysctl_max_unsig_bytes;
-			send->s_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED;
+			send->s_send_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED;
 		}
 
 		/*
 		 * Always signal the last one if we're stopping due to flow control.
 		 */
 		if (flow_controlled && i == (work_alloc-1))
-			send->s_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED;
+			send->s_send_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED;
 
 		rdsdebug("send %p wr %p num_sge %u next %p\n", send,
-			 &send->s_wr, send->s_wr.num_sge, send->s_wr.next);
+			 &send->s_send_wr, send->s_send_wr.num_sge, send->s_send_wr.next);
 
 		sent += len;
 		rm->data.op_dmaoff += len;
@@ -722,7 +722,7 @@ add_header:
 		}
 
 		if (prev)
-			prev->s_wr.next = &send->s_wr;
+			prev->s_send_wr.next = &send->s_send_wr;
 		prev = send;
 
 		pos = (pos + 1) % ic->i_send_ring.w_nr;
@@ -736,7 +736,7 @@ add_header:
 	/* if we finished the message then send completion owns it */
 	if (scat == &rm->data.op_sg[rm->data.op_count]) {
 		prev->s_rm = ic->i_rm;
-		prev->s_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED;
+		prev->s_send_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED;
 		ic->i_rm = NULL;
 	}
 
@@ -748,11 +748,11 @@ add_header:
 		rds_iw_send_add_credits(conn, credit_alloc - i);
 
 	/* XXX need to worry about failed_wr and partial sends. */
-	failed_wr = &first->s_wr;
-	ret = ib_post_send(ic->i_cm_id->qp, &first->s_wr, &failed_wr);
+	failed_wr = &first->s_send_wr;
+	ret = ib_post_send(ic->i_cm_id->qp, &first->s_send_wr, &failed_wr);
 	rdsdebug("ic %p first %p (wr %p) ret %d wr %p\n", ic,
-		 first, &first->s_wr, ret, failed_wr);
-	BUG_ON(failed_wr != &first->s_wr);
+		 first, &first->s_send_wr, ret, failed_wr);
+	BUG_ON(failed_wr != &first->s_send_wr);
 	if (ret) {
 		printk(KERN_WARNING "RDS/IW: ib_post_send to %pI4 "
 		       "returned %d\n", &conn->c_faddr, ret);
@@ -778,14 +778,14 @@ static void rds_iw_build_send_fastreg(struct rds_iw_device *rds_iwdev, struct rd
 	 * in the sg list is added to the fast reg page list and placed
 	 * inside the fast_reg_mr WR.
 	 */
-	send->s_wr.opcode = IB_WR_FAST_REG_MR;
-	send->s_wr.wr.fast_reg.length = len;
-	send->s_wr.wr.fast_reg.rkey = send->s_mr->rkey;
-	send->s_wr.wr.fast_reg.page_list = send->s_page_list;
-	send->s_wr.wr.fast_reg.page_list_len = nent;
-	send->s_wr.wr.fast_reg.page_shift = PAGE_SHIFT;
-	send->s_wr.wr.fast_reg.access_flags = IB_ACCESS_REMOTE_WRITE;
-	send->s_wr.wr.fast_reg.iova_start = sg_addr;
+	send->s_fast_reg_wr.wr.opcode = IB_WR_FAST_REG_MR;
+	send->s_fast_reg_wr.length = len;
+	send->s_fast_reg_wr.rkey = send->s_mr->rkey;
+	send->s_fast_reg_wr.page_list = send->s_page_list;
+	send->s_fast_reg_wr.page_list_len = nent;
+	send->s_fast_reg_wr.page_shift = PAGE_SHIFT;
+	send->s_fast_reg_wr.access_flags = IB_ACCESS_REMOTE_WRITE;
+	send->s_fast_reg_wr.iova_start = sg_addr;
 
 	ib_update_fast_reg_key(send->s_mr, send->s_remap_count++);
 }
@@ -863,7 +863,7 @@ int rds_iw_xmit_rdma(struct rds_connection *conn, struct rm_rdma_op *op)
 	num_sge = op->op_count;
 
 	for (i = 0; i < work_alloc && scat != &op->op_sg[op->op_count]; i++) {
-		send->s_wr.send_flags = 0;
+		send->s_rdma_wr.wr.send_flags = 0;
 		send->s_queued = jiffies;
 
 		/*
@@ -872,7 +872,7 @@ int rds_iw_xmit_rdma(struct rds_connection *conn, struct rm_rdma_op *op)
 		 */
 		if (ic->i_unsignaled_wrs-- == 0) {
 			ic->i_unsignaled_wrs = rds_iw_sysctl_max_unsig_wrs;
-			send->s_wr.send_flags = IB_SEND_SIGNALED;
+			send->s_rdma_wr.wr.send_flags = IB_SEND_SIGNALED;
 		}
 
 		/* To avoid the need to have the plumbing to invalidate the fastreg_mr used
@@ -880,29 +880,30 @@ int rds_iw_xmit_rdma(struct rds_connection *conn, struct rm_rdma_op *op)
 		 * IB_WR_RDMA_READ_WITH_INV will invalidate it after the read has completed.
 		 */
 		if (op->op_write)
-			send->s_wr.opcode = IB_WR_RDMA_WRITE;
+			send->s_rdma_wr.wr.opcode = IB_WR_RDMA_WRITE;
 		else
-			send->s_wr.opcode = IB_WR_RDMA_READ_WITH_INV;
+			send->s_rdma_wr.wr.opcode = IB_WR_RDMA_READ_WITH_INV;
 
-		send->s_wr.wr.rdma.remote_addr = remote_addr;
-		send->s_wr.wr.rdma.rkey = op->op_rkey;
+		send->s_rdma_wr.remote_addr = remote_addr;
+		send->s_rdma_wr.rkey = op->op_rkey;
 		send->s_op = op;
 
 		if (num_sge > rds_iwdev->max_sge) {
-			send->s_wr.num_sge = rds_iwdev->max_sge;
+			send->s_rdma_wr.wr.num_sge = rds_iwdev->max_sge;
 			num_sge -= rds_iwdev->max_sge;
 		} else
-			send->s_wr.num_sge = num_sge;
+			send->s_rdma_wr.wr.num_sge = num_sge;
 
-		send->s_wr.next = NULL;
+		send->s_rdma_wr.wr.next = NULL;
 
 		if (prev)
-			prev->s_wr.next = &send->s_wr;
+			prev->s_send_wr.next = &send->s_rdma_wr.wr;
 
-		for (j = 0; j < send->s_wr.num_sge && scat != &op->op_sg[op->op_count]; j++) {
+		for (j = 0; j < send->s_rdma_wr.wr.num_sge &&
+		     scat != &op->op_sg[op->op_count]; j++) {
 			len = ib_sg_dma_len(ic->i_cm_id->device, scat);
 
-			if (send->s_wr.opcode == IB_WR_RDMA_READ_WITH_INV)
+			if (send->s_rdma_wr.wr.opcode == IB_WR_RDMA_READ_WITH_INV)
 				send->s_page_list->page_list[j] = ib_sg_dma_address(ic->i_cm_id->device, scat);
 			else {
 				send->s_sge[j].addr = ib_sg_dma_address(ic->i_cm_id->device, scat);
@@ -917,15 +918,17 @@ int rds_iw_xmit_rdma(struct rds_connection *conn, struct rm_rdma_op *op)
 			scat++;
 		}
 
-		if (send->s_wr.opcode == IB_WR_RDMA_READ_WITH_INV) {
-			send->s_wr.num_sge = 1;
+		if (send->s_rdma_wr.wr.opcode == IB_WR_RDMA_READ_WITH_INV) {
+			send->s_rdma_wr.wr.num_sge = 1;
 			send->s_sge[0].addr = conn->c_xmit_rm->m_rs->rs_user_addr;
 			send->s_sge[0].length = conn->c_xmit_rm->m_rs->rs_user_bytes;
 			send->s_sge[0].lkey = ic->i_sends[fr_pos].s_mr->lkey;
 		}
 
 		rdsdebug("send %p wr %p num_sge %u next %p\n", send,
-			&send->s_wr, send->s_wr.num_sge, send->s_wr.next);
+			&send->s_rdma_wr,
+			send->s_rdma_wr.wr.num_sge,
+			send->s_rdma_wr.wr.next);
 
 		prev = send;
 		if (++send == &ic->i_sends[ic->i_send_ring.w_nr])
@@ -934,7 +937,7 @@ int rds_iw_xmit_rdma(struct rds_connection *conn, struct rm_rdma_op *op)
 
 	/* if we finished the message then send completion owns it */
 	if (scat == &op->op_sg[op->op_count])
-		first->s_wr.send_flags = IB_SEND_SIGNALED;
+		first->s_rdma_wr.wr.send_flags = IB_SEND_SIGNALED;
 
 	if (i < work_alloc) {
 		rds_iw_ring_unalloc(&ic->i_send_ring, work_alloc - i);
@@ -953,11 +956,11 @@ int rds_iw_xmit_rdma(struct rds_connection *conn, struct rm_rdma_op *op)
 		work_alloc++;
 	}
 
-	failed_wr = &first->s_wr;
-	ret = ib_post_send(ic->i_cm_id->qp, &first->s_wr, &failed_wr);
+	failed_wr = &first->s_rdma_wr.wr;
+	ret = ib_post_send(ic->i_cm_id->qp, &first->s_rdma_wr.wr, &failed_wr);
 	rdsdebug("ic %p first %p (wr %p) ret %d wr %p\n", ic,
-		 first, &first->s_wr, ret, failed_wr);
-	BUG_ON(failed_wr != &first->s_wr);
+		 first, &first->s_rdma_wr, ret, failed_wr);
+	BUG_ON(failed_wr != &first->s_rdma_wr.wr);
 	if (ret) {
 		printk(KERN_WARNING "RDS/IW: rdma ib_post_send to %pI4 "
 		       "returned %d\n", &conn->c_faddr, ret);