From 7b0b01aa8f48cd237322cbffa05662a9c6b156f8 Mon Sep 17 00:00:00 2001 From: Dean Luick Date: Wed, 3 Feb 2016 14:35:49 -0800 Subject: [PATCH] staging/rdma/hfi1: Split last 8 bytes of copy to user buffer Copy the last 8 bytes of user mode RC WRITE_ONLY and WRITE_LAST opcodes separately from the rest of the data. It is a de-facto standard for some MPI implementations to use a poll on the last few bytes of a verbs message to indicate that the message has been received rather than follow the required function method. The driver uses the kernel memcpy routine, which becomes "rep movsb" on modern machines. This copy, while very fast, does not guarantee in-order copy completion and the result is an occasional perceived corrupted packet. Avoid the issue by splitting the last 8 bytes to copy from the verbs opcodes where it matters and performing an in-order byte copy. Reviewed-by: Mike Marciniszyn Signed-off-by: Dean Luick Signed-off-by: Jubin John Signed-off-by: Doug Ledford --- drivers/staging/rdma/hfi1/rc.c | 17 +++++++++++------ drivers/staging/rdma/hfi1/ruc.c | 8 ++++++-- drivers/staging/rdma/hfi1/uc.c | 10 +++++----- drivers/staging/rdma/hfi1/ud.c | 9 +++++---- drivers/staging/rdma/hfi1/verbs.c | 31 +++++++++++++++++++++++++++++-- drivers/staging/rdma/hfi1/verbs.h | 2 +- 6 files changed, 57 insertions(+), 20 deletions(-) diff --git a/drivers/staging/rdma/hfi1/rc.c b/drivers/staging/rdma/hfi1/rc.c index 50559fd14a70..371edc3dd4f6 100644 --- a/drivers/staging/rdma/hfi1/rc.c +++ b/drivers/staging/rdma/hfi1/rc.c @@ -1539,7 +1539,7 @@ read_middle: qp->s_rdma_read_len -= pmtu; update_last_psn(qp, psn); spin_unlock_irqrestore(&qp->s_lock, flags); - hfi1_copy_sge(&qp->s_rdma_read_sge, data, pmtu, 0); + hfi1_copy_sge(&qp->s_rdma_read_sge, data, pmtu, 0, 0); goto bail; case OP(RDMA_READ_RESPONSE_ONLY): @@ -1583,7 +1583,7 @@ read_last: if (unlikely(tlen != qp->s_rdma_read_len)) goto ack_len_err; aeth = be32_to_cpu(ohdr->u.aeth); - hfi1_copy_sge(&qp->s_rdma_read_sge, data, tlen, 0); + hfi1_copy_sge(&qp->s_rdma_read_sge, data, tlen, 0, 0); WARN_ON(qp->s_rdma_read_sge.num_sge); (void) do_rc_ack(qp, aeth, psn, OP(RDMA_READ_RESPONSE_LAST), 0, rcd); @@ -1977,6 +1977,7 @@ void hfi1_rc_rcv(struct hfi1_packet *packet) unsigned long flags; u32 bth1; int ret, is_fecn = 0; + int copy_last = 0; bth0 = be32_to_cpu(ohdr->bth[0]); if (hfi1_ruc_check_hdr(ibp, hdr, rcv_flags & HFI1_HAS_GRH, qp, bth0)) @@ -2081,7 +2082,7 @@ send_middle: qp->r_rcv_len += pmtu; if (unlikely(qp->r_rcv_len > qp->r_len)) goto nack_inv; - hfi1_copy_sge(&qp->r_sge, data, pmtu, 1); + hfi1_copy_sge(&qp->r_sge, data, pmtu, 1, 0); break; case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE): @@ -2109,8 +2110,10 @@ send_last_imm: wc.ex.imm_data = ohdr->u.imm_data; wc.wc_flags = IB_WC_WITH_IMM; goto send_last; - case OP(SEND_LAST): case OP(RDMA_WRITE_LAST): + copy_last = ibpd_to_rvtpd(qp->ibqp.pd)->user; + /* fall through */ + case OP(SEND_LAST): no_immediate_data: wc.wc_flags = 0; wc.ex.imm_data = 0; @@ -2126,7 +2129,7 @@ send_last: wc.byte_len = tlen + qp->r_rcv_len; if (unlikely(wc.byte_len > qp->r_len)) goto nack_inv; - hfi1_copy_sge(&qp->r_sge, data, tlen, 1); + hfi1_copy_sge(&qp->r_sge, data, tlen, 1, copy_last); rvt_put_ss(&qp->r_sge); qp->r_msn++; if (!test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags)) @@ -2163,8 +2166,10 @@ send_last: (bth0 & IB_BTH_SOLICITED) != 0); break; - case OP(RDMA_WRITE_FIRST): case OP(RDMA_WRITE_ONLY): + copy_last = 1; + /* fall through */ + case OP(RDMA_WRITE_FIRST): case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE): if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE))) goto nack_inv; diff --git a/drivers/staging/rdma/hfi1/ruc.c b/drivers/staging/rdma/hfi1/ruc.c index f09badbfa51c..6aeea6c4b236 100644 --- a/drivers/staging/rdma/hfi1/ruc.c +++ b/drivers/staging/rdma/hfi1/ruc.c @@ -370,6 +370,7 @@ static void ruc_loopback(struct rvt_qp *sqp) enum ib_wc_status send_status; int release; int ret; + int copy_last = 0; rcu_read_lock(); @@ -459,10 +460,13 @@ again: goto op_err; if (!ret) goto rnr_nak; - /* FALLTHROUGH */ + /* skip copy_last set and qp_access_flags recheck */ + goto do_write; case IB_WR_RDMA_WRITE: + copy_last = ibpd_to_rvtpd(qp->ibqp.pd)->user; if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE))) goto inv_err; +do_write: if (wqe->length == 0) if (unlikely(!rvt_rkey_ok(qp, &qp->r_sge.sge, wqe->length, wqe->rdma_wr.remote_addr, @@ -526,7 +530,7 @@ again: if (len > sge->sge_length) len = sge->sge_length; WARN_ON_ONCE(len == 0); - hfi1_copy_sge(&qp->r_sge, sge->vaddr, len, release); + hfi1_copy_sge(&qp->r_sge, sge->vaddr, len, release, copy_last); sge->vaddr += len; sge->length -= len; sge->sge_length -= len; diff --git a/drivers/staging/rdma/hfi1/uc.c b/drivers/staging/rdma/hfi1/uc.c index 1e50d303c024..0aa604b7557b 100644 --- a/drivers/staging/rdma/hfi1/uc.c +++ b/drivers/staging/rdma/hfi1/uc.c @@ -418,7 +418,7 @@ send_first: qp->r_rcv_len += pmtu; if (unlikely(qp->r_rcv_len > qp->r_len)) goto rewind; - hfi1_copy_sge(&qp->r_sge, data, pmtu, 0); + hfi1_copy_sge(&qp->r_sge, data, pmtu, 0, 0); break; case OP(SEND_LAST_WITH_IMMEDIATE): @@ -443,7 +443,7 @@ send_last: if (unlikely(wc.byte_len > qp->r_len)) goto rewind; wc.opcode = IB_WC_RECV; - hfi1_copy_sge(&qp->r_sge, data, tlen, 0); + hfi1_copy_sge(&qp->r_sge, data, tlen, 0, 0); rvt_put_ss(&qp->s_rdma_read_sge); last_imm: wc.wr_id = qp->r_wr_id; @@ -518,7 +518,7 @@ rdma_first: qp->r_rcv_len += pmtu; if (unlikely(qp->r_rcv_len > qp->r_len)) goto drop; - hfi1_copy_sge(&qp->r_sge, data, pmtu, 1); + hfi1_copy_sge(&qp->r_sge, data, pmtu, 1, 0); break; case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE): @@ -547,7 +547,7 @@ rdma_last_imm: } wc.byte_len = qp->r_len; wc.opcode = IB_WC_RECV_RDMA_WITH_IMM; - hfi1_copy_sge(&qp->r_sge, data, tlen, 1); + hfi1_copy_sge(&qp->r_sge, data, tlen, 1, 0); rvt_put_ss(&qp->r_sge); goto last_imm; @@ -563,7 +563,7 @@ rdma_last: tlen -= (hdrsize + pad + 4); if (unlikely(tlen + qp->r_rcv_len != qp->r_len)) goto drop; - hfi1_copy_sge(&qp->r_sge, data, tlen, 1); + hfi1_copy_sge(&qp->r_sge, data, tlen, 1, 0); rvt_put_ss(&qp->r_sge); break; diff --git a/drivers/staging/rdma/hfi1/ud.c b/drivers/staging/rdma/hfi1/ud.c index 2eae16769688..fdf6e3bee8f1 100644 --- a/drivers/staging/rdma/hfi1/ud.c +++ b/drivers/staging/rdma/hfi1/ud.c @@ -187,7 +187,7 @@ static void ud_loopback(struct rvt_qp *sqp, struct rvt_swqe *swqe) if (ah_attr->ah_flags & IB_AH_GRH) { hfi1_copy_sge(&qp->r_sge, &ah_attr->grh, - sizeof(struct ib_grh), 1); + sizeof(struct ib_grh), 1, 0); wc.wc_flags |= IB_WC_GRH; } else hfi1_skip_sge(&qp->r_sge, sizeof(struct ib_grh), 1); @@ -203,7 +203,7 @@ static void ud_loopback(struct rvt_qp *sqp, struct rvt_swqe *swqe) if (len > sge->sge_length) len = sge->sge_length; WARN_ON_ONCE(len == 0); - hfi1_copy_sge(&qp->r_sge, sge->vaddr, len, 1); + hfi1_copy_sge(&qp->r_sge, sge->vaddr, len, 1, 0); sge->vaddr += len; sge->length -= len; sge->sge_length -= len; @@ -836,11 +836,12 @@ void hfi1_ud_rcv(struct hfi1_packet *packet) } if (has_grh) { hfi1_copy_sge(&qp->r_sge, &hdr->u.l.grh, - sizeof(struct ib_grh), 1); + sizeof(struct ib_grh), 1, 0); wc.wc_flags |= IB_WC_GRH; } else hfi1_skip_sge(&qp->r_sge, sizeof(struct ib_grh), 1); - hfi1_copy_sge(&qp->r_sge, data, wc.byte_len - sizeof(struct ib_grh), 1); + hfi1_copy_sge(&qp->r_sge, data, wc.byte_len - sizeof(struct ib_grh), + 1, 0); rvt_put_ss(&qp->r_sge); if (!test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags)) return; diff --git a/drivers/staging/rdma/hfi1/verbs.c b/drivers/staging/rdma/hfi1/verbs.c index d617324e3c48..8f351bc157df 100644 --- a/drivers/staging/rdma/hfi1/verbs.c +++ b/drivers/staging/rdma/hfi1/verbs.c @@ -242,14 +242,28 @@ __be64 ib_hfi1_sys_image_guid; * @ss: the SGE state * @data: the data to copy * @length: the length of the data + * @copy_last: do a separate copy of the last 8 bytes */ void hfi1_copy_sge( struct rvt_sge_state *ss, void *data, u32 length, - int release) + int release, + int copy_last) { struct rvt_sge *sge = &ss->sge; + int in_last = 0; + int i; + + if (copy_last) { + if (length > 8) { + length -= 8; + } else { + copy_last = 0; + in_last = 1; + } + } +again: while (length) { u32 len = sge->length; @@ -258,7 +272,13 @@ void hfi1_copy_sge( if (len > sge->sge_length) len = sge->sge_length; WARN_ON_ONCE(len == 0); - memcpy(sge->vaddr, data, len); + if (in_last) { + /* enforce byte transer ordering */ + for (i = 0; i < len; i++) + ((u8 *)sge->vaddr)[i] = ((u8 *)data)[i]; + } else { + memcpy(sge->vaddr, data, len); + } sge->vaddr += len; sge->length -= len; sge->sge_length -= len; @@ -281,6 +301,13 @@ void hfi1_copy_sge( data += len; length -= len; } + + if (copy_last) { + copy_last = 0; + in_last = 1; + length = 8; + goto again; + } } /** diff --git a/drivers/staging/rdma/hfi1/verbs.h b/drivers/staging/rdma/hfi1/verbs.h index ac84dd70c6c7..afb2d7fd6ae6 100644 --- a/drivers/staging/rdma/hfi1/verbs.h +++ b/drivers/staging/rdma/hfi1/verbs.h @@ -398,7 +398,7 @@ void hfi1_put_txreq(struct verbs_txreq *tx); int hfi1_verbs_send(struct rvt_qp *qp, struct hfi1_pkt_state *ps); void hfi1_copy_sge(struct rvt_sge_state *ss, void *data, u32 length, - int release); + int release, int copy_last); void hfi1_skip_sge(struct rvt_sge_state *ss, u32 length, int release); -- 2.20.1