RDMA/cxgb4: Use DSGLs for fastreg and adapter memory writes for T5.

It enables direct DMA by HW to memory region PBL arrays and fast register PBL
arrays from host memory, vs the T4 way of passing these arrays in the WR itself.
The result is lower latency for memory registration, and larger PBL array
support for fast register operations.

This patch also updates ULP_TX_MEM_WRITE command fields for T5. Ordering bit of
ULP_TX_MEM_WRITE is at bit position 22 in T5 and at 23 in T4.

Signed-off-by: Vipul Pandya <vipul@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 53 insertions, 23 deletions

diff --git a/drivers/infiniband/hw/cxgb4/qp.c b/drivers/infiniband/hw/cxgb4/qp.c
index 28592d45809b..90833d701631 100644
--- a/drivers/infiniband/hw/cxgb4/qp.c
+++ b/drivers/infiniband/hw/cxgb4/qp.c
@@ -54,6 +54,10 @@ MODULE_PARM_DESC(db_coalescing_threshold,
 		 "QP count/threshold that triggers"
 		 " disabling db coalescing (default = 0)");
 
+static int max_fr_immd = T4_MAX_FR_IMMD;
+module_param(max_fr_immd, int, 0644);
+MODULE_PARM_DESC(max_fr_immd, "fastreg threshold for using DSGL instead of immedate");
+
 static void set_state(struct c4iw_qp *qhp, enum c4iw_qp_state state)
 {
 	unsigned long flag;
@@ -539,7 +543,7 @@ static int build_rdma_recv(struct c4iw_qp *qhp, union t4_recv_wr *wqe,
 }
 
 static int build_fastreg(struct t4_sq *sq, union t4_wr *wqe,
-			 struct ib_send_wr *wr, u8 *len16)
+			 struct ib_send_wr *wr, u8 *len16, u8 t5dev)
 {
 
 	struct fw_ri_immd *imdp;
@@ -561,28 +565,51 @@ static int build_fastreg(struct t4_sq *sq, union t4_wr *wqe,
 	wqe->fr.va_hi = cpu_to_be32(wr->wr.fast_reg.iova_start >> 32);
 	wqe->fr.va_lo_fbo = cpu_to_be32(wr->wr.fast_reg.iova_start &
 					0xffffffff);
-	WARN_ON(pbllen > T4_MAX_FR_IMMD);
-	imdp = (struct fw_ri_immd *)(&wqe->fr + 1);
-	imdp->op = FW_RI_DATA_IMMD;
-	imdp->r1 = 0;
-	imdp->r2 = 0;
-	imdp->immdlen = cpu_to_be32(pbllen);
-	p = (__be64 *)(imdp + 1);
-	rem = pbllen;
-	for (i = 0; i < wr->wr.fast_reg.page_list_len; i++) {
-		*p = cpu_to_be64((u64)wr->wr.fast_reg.page_list->page_list[i]);
-		rem -= sizeof *p;
-		if (++p == (__be64 *)&sq->queue[sq->size])
-			p = (__be64 *)sq->queue;
-	}
-	BUG_ON(rem < 0);
-	while (rem) {
-		*p = 0;
-		rem -= sizeof *p;
-		if (++p == (__be64 *)&sq->queue[sq->size])
-			p = (__be64 *)sq->queue;
+
+	if (t5dev && use_dsgl && (pbllen > max_fr_immd)) {
+		struct c4iw_fr_page_list *c4pl =
+			to_c4iw_fr_page_list(wr->wr.fast_reg.page_list);
+		struct fw_ri_dsgl *sglp;
+
+		for (i = 0; i < wr->wr.fast_reg.page_list_len; i++) {
+			wr->wr.fast_reg.page_list->page_list[i] = (__force u64)
+				cpu_to_be64((u64)
+				wr->wr.fast_reg.page_list->page_list[i]);
+		}
+
+		sglp = (struct fw_ri_dsgl *)(&wqe->fr + 1);
+		sglp->op = FW_RI_DATA_DSGL;
+		sglp->r1 = 0;
+		sglp->nsge = cpu_to_be16(1);
+		sglp->addr0 = cpu_to_be64(c4pl->dma_addr);
+		sglp->len0 = cpu_to_be32(pbllen);
+
+		*len16 = DIV_ROUND_UP(sizeof(wqe->fr) + sizeof(*sglp), 16);
+	} else {
+		imdp = (struct fw_ri_immd *)(&wqe->fr + 1);
+		imdp->op = FW_RI_DATA_IMMD;
+		imdp->r1 = 0;
+		imdp->r2 = 0;
+		imdp->immdlen = cpu_to_be32(pbllen);
+		p = (__be64 *)(imdp + 1);
+		rem = pbllen;
+		for (i = 0; i < wr->wr.fast_reg.page_list_len; i++) {
+			*p = cpu_to_be64(
+				(u64)wr->wr.fast_reg.page_list->page_list[i]);
+			rem -= sizeof(*p);
+			if (++p == (__be64 *)&sq->queue[sq->size])
+				p = (__be64 *)sq->queue;
+		}
+		BUG_ON(rem < 0);
+		while (rem) {
+			*p = 0;
+			rem -= sizeof(*p);
+			if (++p == (__be64 *)&sq->queue[sq->size])
+				p = (__be64 *)sq->queue;
+		}
+		*len16 = DIV_ROUND_UP(sizeof(wqe->fr) + sizeof(*imdp)
+				      + pbllen, 16);
 	}
-	*len16 = DIV_ROUND_UP(sizeof wqe->fr + sizeof *imdp + pbllen, 16);
 	return 0;
 }
 
@@ -683,7 +710,10 @@ int c4iw_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
 		case IB_WR_FAST_REG_MR:
 			fw_opcode = FW_RI_FR_NSMR_WR;
 			swsqe->opcode = FW_RI_FAST_REGISTER;
-			err = build_fastreg(&qhp->wq.sq, wqe, wr, &len16);
+			err = build_fastreg(&qhp->wq.sq, wqe, wr, &len16,
+					    is_t5(
+					    qhp->rhp->rdev.lldi.adapter_type) ?
+					    1 : 0);
 			break;
 		case IB_WR_LOCAL_INV:
 			if (wr->send_flags & IB_SEND_FENCE)