RDMA/cxgb4: Support variable sized work requests
T4 EQ entries are in multiples of 64 bytes. Currently the RDMA SQ and
RQ use fixed sized entries composed of 4 EQ entries for the SQ and 2
EQ entries for the RQ. For optimial latency with small IO, we need to
change this so the HW only needs to DMA the EQ entries actually used
by a given work request.
Implementation:
- add wq_pidx counter to track where we are in the EQ. cidx/pidx are
used for the sw sq/rq tracking and flow control.
- the variable part of work requests is the SGL. Add new functions to
build the SGL and/or immediate data directly in the EQ memory
wrapping when needed.
- adjust the min burst size for the EQ contexts to 64B.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/hw/cxgb4/qp.c b/drivers/infiniband/hw/cxgb4/qp.c
index b88b1af..657a5b3 100644
--- a/drivers/infiniband/hw/cxgb4/qp.c
+++ b/drivers/infiniband/hw/cxgb4/qp.c
@@ -162,7 +162,7 @@
res->u.sqrq.dcaen_to_eqsize = cpu_to_be32(
V_FW_RI_RES_WR_DCAEN(0) |
V_FW_RI_RES_WR_DCACPU(0) |
- V_FW_RI_RES_WR_FBMIN(3) |
+ V_FW_RI_RES_WR_FBMIN(2) |
V_FW_RI_RES_WR_FBMAX(3) |
V_FW_RI_RES_WR_CIDXFTHRESHO(0) |
V_FW_RI_RES_WR_CIDXFTHRESH(0) |
@@ -185,7 +185,7 @@
res->u.sqrq.dcaen_to_eqsize = cpu_to_be32(
V_FW_RI_RES_WR_DCAEN(0) |
V_FW_RI_RES_WR_DCACPU(0) |
- V_FW_RI_RES_WR_FBMIN(3) |
+ V_FW_RI_RES_WR_FBMIN(2) |
V_FW_RI_RES_WR_FBMAX(3) |
V_FW_RI_RES_WR_CIDXFTHRESHO(0) |
V_FW_RI_RES_WR_CIDXFTHRESH(0) |
@@ -235,12 +235,78 @@
return -ENOMEM;
}
-static int build_rdma_send(union t4_wr *wqe, struct ib_send_wr *wr, u8 *len16)
+static int build_immd(struct t4_sq *sq, struct fw_ri_immd *immdp,
+ struct ib_send_wr *wr, int max, u32 *plenp)
+{
+ u8 *dstp, *srcp;
+ u32 plen = 0;
+ int i;
+ int rem, len;
+
+ dstp = (u8 *)immdp->data;
+ for (i = 0; i < wr->num_sge; i++) {
+ if ((plen + wr->sg_list[i].length) > max)
+ return -EMSGSIZE;
+ srcp = (u8 *)(unsigned long)wr->sg_list[i].addr;
+ plen += wr->sg_list[i].length;
+ rem = wr->sg_list[i].length;
+ while (rem) {
+ if (dstp == (u8 *)&sq->queue[sq->size])
+ dstp = (u8 *)sq->queue;
+ if (rem <= (u8 *)&sq->queue[sq->size] - dstp)
+ len = rem;
+ else
+ len = (u8 *)&sq->queue[sq->size] - dstp;
+ memcpy(dstp, srcp, len);
+ dstp += len;
+ srcp += len;
+ rem -= len;
+ }
+ }
+ immdp->op = FW_RI_DATA_IMMD;
+ immdp->r1 = 0;
+ immdp->r2 = 0;
+ immdp->immdlen = cpu_to_be32(plen);
+ *plenp = plen;
+ return 0;
+}
+
+static int build_isgl(__be64 *queue_start, __be64 *queue_end,
+ struct fw_ri_isgl *isglp, struct ib_sge *sg_list,
+ int num_sge, u32 *plenp)
+
{
int i;
+ u32 plen = 0;
+ __be64 *flitp = (__be64 *)isglp->sge;
+
+ for (i = 0; i < num_sge; i++) {
+ if ((plen + sg_list[i].length) < plen)
+ return -EMSGSIZE;
+ plen += sg_list[i].length;
+ *flitp = cpu_to_be64(((u64)sg_list[i].lkey << 32) |
+ sg_list[i].length);
+ if (++flitp == queue_end)
+ flitp = queue_start;
+ *flitp = cpu_to_be64(sg_list[i].addr);
+ if (++flitp == queue_end)
+ flitp = queue_start;
+ }
+ isglp->op = FW_RI_DATA_ISGL;
+ isglp->r1 = 0;
+ isglp->nsge = cpu_to_be16(num_sge);
+ isglp->r2 = 0;
+ if (plenp)
+ *plenp = plen;
+ return 0;
+}
+
+static int build_rdma_send(struct t4_sq *sq, union t4_wr *wqe,
+ struct ib_send_wr *wr, u8 *len16)
+{
u32 plen;
int size;
- u8 *datap;
+ int ret;
if (wr->num_sge > T4_MAX_SEND_SGE)
return -EINVAL;
@@ -267,43 +333,23 @@
default:
return -EINVAL;
}
+
plen = 0;
if (wr->num_sge) {
if (wr->send_flags & IB_SEND_INLINE) {
- datap = (u8 *)wqe->send.u.immd_src[0].data;
- for (i = 0; i < wr->num_sge; i++) {
- if ((plen + wr->sg_list[i].length) >
- T4_MAX_SEND_INLINE) {
- return -EMSGSIZE;
- }
- plen += wr->sg_list[i].length;
- memcpy(datap,
- (void *)(unsigned long)wr->sg_list[i].addr,
- wr->sg_list[i].length);
- datap += wr->sg_list[i].length;
- }
- wqe->send.u.immd_src[0].op = FW_RI_DATA_IMMD;
- wqe->send.u.immd_src[0].r1 = 0;
- wqe->send.u.immd_src[0].r2 = 0;
- wqe->send.u.immd_src[0].immdlen = cpu_to_be32(plen);
+ ret = build_immd(sq, wqe->send.u.immd_src, wr,
+ T4_MAX_SEND_INLINE, &plen);
+ if (ret)
+ return ret;
size = sizeof wqe->send + sizeof(struct fw_ri_immd) +
plen;
} else {
- for (i = 0; i < wr->num_sge; i++) {
- if ((plen + wr->sg_list[i].length) < plen)
- return -EMSGSIZE;
- plen += wr->sg_list[i].length;
- wqe->send.u.isgl_src[0].sge[i].stag =
- cpu_to_be32(wr->sg_list[i].lkey);
- wqe->send.u.isgl_src[0].sge[i].len =
- cpu_to_be32(wr->sg_list[i].length);
- wqe->send.u.isgl_src[0].sge[i].to =
- cpu_to_be64(wr->sg_list[i].addr);
- }
- wqe->send.u.isgl_src[0].op = FW_RI_DATA_ISGL;
- wqe->send.u.isgl_src[0].r1 = 0;
- wqe->send.u.isgl_src[0].nsge = cpu_to_be16(wr->num_sge);
- wqe->send.u.isgl_src[0].r2 = 0;
+ ret = build_isgl((__be64 *)sq->queue,
+ (__be64 *)&sq->queue[sq->size],
+ wqe->send.u.isgl_src,
+ wr->sg_list, wr->num_sge, &plen);
+ if (ret)
+ return ret;
size = sizeof wqe->send + sizeof(struct fw_ri_isgl) +
wr->num_sge * sizeof(struct fw_ri_sge);
}
@@ -313,62 +359,40 @@
wqe->send.u.immd_src[0].r2 = 0;
wqe->send.u.immd_src[0].immdlen = 0;
size = sizeof wqe->send + sizeof(struct fw_ri_immd);
+ plen = 0;
}
*len16 = DIV_ROUND_UP(size, 16);
wqe->send.plen = cpu_to_be32(plen);
return 0;
}
-static int build_rdma_write(union t4_wr *wqe, struct ib_send_wr *wr, u8 *len16)
+static int build_rdma_write(struct t4_sq *sq, union t4_wr *wqe,
+ struct ib_send_wr *wr, u8 *len16)
{
- int i;
u32 plen;
int size;
- u8 *datap;
+ int ret;
- if (wr->num_sge > T4_MAX_WRITE_SGE)
+ if (wr->num_sge > T4_MAX_SEND_SGE)
return -EINVAL;
wqe->write.r2 = 0;
wqe->write.stag_sink = cpu_to_be32(wr->wr.rdma.rkey);
wqe->write.to_sink = cpu_to_be64(wr->wr.rdma.remote_addr);
- plen = 0;
if (wr->num_sge) {
if (wr->send_flags & IB_SEND_INLINE) {
- datap = (u8 *)wqe->write.u.immd_src[0].data;
- for (i = 0; i < wr->num_sge; i++) {
- if ((plen + wr->sg_list[i].length) >
- T4_MAX_WRITE_INLINE) {
- return -EMSGSIZE;
- }
- plen += wr->sg_list[i].length;
- memcpy(datap,
- (void *)(unsigned long)wr->sg_list[i].addr,
- wr->sg_list[i].length);
- datap += wr->sg_list[i].length;
- }
- wqe->write.u.immd_src[0].op = FW_RI_DATA_IMMD;
- wqe->write.u.immd_src[0].r1 = 0;
- wqe->write.u.immd_src[0].r2 = 0;
- wqe->write.u.immd_src[0].immdlen = cpu_to_be32(plen);
+ ret = build_immd(sq, wqe->write.u.immd_src, wr,
+ T4_MAX_WRITE_INLINE, &plen);
+ if (ret)
+ return ret;
size = sizeof wqe->write + sizeof(struct fw_ri_immd) +
plen;
} else {
- for (i = 0; i < wr->num_sge; i++) {
- if ((plen + wr->sg_list[i].length) < plen)
- return -EMSGSIZE;
- plen += wr->sg_list[i].length;
- wqe->write.u.isgl_src[0].sge[i].stag =
- cpu_to_be32(wr->sg_list[i].lkey);
- wqe->write.u.isgl_src[0].sge[i].len =
- cpu_to_be32(wr->sg_list[i].length);
- wqe->write.u.isgl_src[0].sge[i].to =
- cpu_to_be64(wr->sg_list[i].addr);
- }
- wqe->write.u.isgl_src[0].op = FW_RI_DATA_ISGL;
- wqe->write.u.isgl_src[0].r1 = 0;
- wqe->write.u.isgl_src[0].nsge =
- cpu_to_be16(wr->num_sge);
- wqe->write.u.isgl_src[0].r2 = 0;
+ ret = build_isgl((__be64 *)sq->queue,
+ (__be64 *)&sq->queue[sq->size],
+ wqe->write.u.isgl_src,
+ wr->sg_list, wr->num_sge, &plen);
+ if (ret)
+ return ret;
size = sizeof wqe->write + sizeof(struct fw_ri_isgl) +
wr->num_sge * sizeof(struct fw_ri_sge);
}
@@ -378,6 +402,7 @@
wqe->write.u.immd_src[0].r2 = 0;
wqe->write.u.immd_src[0].immdlen = 0;
size = sizeof wqe->write + sizeof(struct fw_ri_immd);
+ plen = 0;
}
*len16 = DIV_ROUND_UP(size, 16);
wqe->write.plen = cpu_to_be32(plen);
@@ -416,29 +441,13 @@
static int build_rdma_recv(struct c4iw_qp *qhp, union t4_recv_wr *wqe,
struct ib_recv_wr *wr, u8 *len16)
{
- int i;
- int plen = 0;
+ int ret;
- for (i = 0; i < wr->num_sge; i++) {
- if ((plen + wr->sg_list[i].length) < plen)
- return -EMSGSIZE;
- plen += wr->sg_list[i].length;
- wqe->recv.isgl.sge[i].stag =
- cpu_to_be32(wr->sg_list[i].lkey);
- wqe->recv.isgl.sge[i].len =
- cpu_to_be32(wr->sg_list[i].length);
- wqe->recv.isgl.sge[i].to =
- cpu_to_be64(wr->sg_list[i].addr);
- }
- for (; i < T4_MAX_RECV_SGE; i++) {
- wqe->recv.isgl.sge[i].stag = 0;
- wqe->recv.isgl.sge[i].len = 0;
- wqe->recv.isgl.sge[i].to = 0;
- }
- wqe->recv.isgl.op = FW_RI_DATA_ISGL;
- wqe->recv.isgl.r1 = 0;
- wqe->recv.isgl.nsge = cpu_to_be16(wr->num_sge);
- wqe->recv.isgl.r2 = 0;
+ ret = build_isgl((__be64 *)qhp->wq.rq.queue,
+ (__be64 *)&qhp->wq.rq.queue[qhp->wq.rq.size],
+ &wqe->recv.isgl, wr->sg_list, wr->num_sge, NULL);
+ if (ret)
+ return ret;
*len16 = DIV_ROUND_UP(sizeof wqe->recv +
wr->num_sge * sizeof(struct fw_ri_sge), 16);
return 0;
@@ -547,7 +556,9 @@
*bad_wr = wr;
break;
}
- wqe = &qhp->wq.sq.queue[qhp->wq.sq.pidx];
+ wqe = (union t4_wr *)((u8 *)qhp->wq.sq.queue +
+ qhp->wq.sq.wq_pidx * T4_EQ_ENTRY_SIZE);
+
fw_flags = 0;
if (wr->send_flags & IB_SEND_SOLICITED)
fw_flags |= FW_RI_SOLICITED_EVENT_FLAG;
@@ -564,12 +575,12 @@
swsqe->opcode = FW_RI_SEND;
else
swsqe->opcode = FW_RI_SEND_WITH_INV;
- err = build_rdma_send(wqe, wr, &len16);
+ err = build_rdma_send(&qhp->wq.sq, wqe, wr, &len16);
break;
case IB_WR_RDMA_WRITE:
fw_opcode = FW_RI_RDMA_WRITE_WR;
swsqe->opcode = FW_RI_RDMA_WRITE;
- err = build_rdma_write(wqe, wr, &len16);
+ err = build_rdma_write(&qhp->wq.sq, wqe, wr, &len16);
break;
case IB_WR_RDMA_READ:
case IB_WR_RDMA_READ_WITH_INV:
@@ -619,8 +630,8 @@
swsqe->opcode, swsqe->read_len);
wr = wr->next;
num_wrs--;
- t4_sq_produce(&qhp->wq);
- idx++;
+ t4_sq_produce(&qhp->wq, len16);
+ idx += DIV_ROUND_UP(len16*16, T4_EQ_ENTRY_SIZE);
}
if (t4_wq_db_enabled(&qhp->wq))
t4_ring_sq_db(&qhp->wq, idx);
@@ -656,7 +667,9 @@
*bad_wr = wr;
break;
}
- wqe = &qhp->wq.rq.queue[qhp->wq.rq.pidx];
+ wqe = (union t4_recv_wr *)((u8 *)qhp->wq.rq.queue +
+ qhp->wq.rq.wq_pidx *
+ T4_EQ_ENTRY_SIZE);
if (num_wrs)
err = build_rdma_recv(qhp, wqe, wr, &len16);
else
@@ -675,15 +688,12 @@
wqe->recv.r2[1] = 0;
wqe->recv.r2[2] = 0;
wqe->recv.len16 = len16;
- if (len16 < 5)
- wqe->flits[8] = 0;
-
PDBG("%s cookie 0x%llx pidx %u\n", __func__,
(unsigned long long) wr->wr_id, qhp->wq.rq.pidx);
- t4_rq_produce(&qhp->wq);
+ t4_rq_produce(&qhp->wq, len16);
+ idx += DIV_ROUND_UP(len16*16, T4_EQ_ENTRY_SIZE);
wr = wr->next;
num_wrs--;
- idx++;
}
if (t4_wq_db_enabled(&qhp->wq))
t4_ring_rq_db(&qhp->wq, idx);