Convert all completions to use the new completion routine that fixes a race between post send and completion where fields from a SWQE can be read after SWQE has been freed. This patch also addresses issues reported in https://marc.info/?l=linux-kernel&m=155656897409107&w=2. The reserved operation path has no need for any barrier. The barrier for the other path is addressed by the smp_load_acquire() barrier. Cc: Andrea Parri <andrea.parri@xxxxxxxxxxxxxxxxxxxx> Reviewed-by: Michael J. Ruhl <michael.j.ruhl@xxxxxxxxx> Signed-off-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx> Signed-off-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx> Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx> --- drivers/infiniband/hw/hfi1/rc.c | 26 ++++----------------- drivers/infiniband/hw/qib/qib_rc.c | 26 ++++----------------- drivers/infiniband/sw/rdmavt/qp.c | 31 ++++++++----------------- include/rdma/rdmavt_qp.h | 36 ------------------------------ 4 files changed, 17 insertions(+), 102 deletions(-) diff --git a/drivers/infiniband/hw/hfi1/rc.c b/drivers/infiniband/hw/hfi1/rc.c index 7c8cfb149da09..235bdbc706acc 100644 --- a/drivers/infiniband/hw/hfi1/rc.c +++ b/drivers/infiniband/hw/hfi1/rc.c @@ -1830,23 +1830,14 @@ void hfi1_rc_send_complete(struct rvt_qp *qp, struct hfi1_opa_header *opah) } while (qp->s_last != qp->s_acked) { - u32 s_last; - wqe = rvt_get_swqe_ptr(qp, qp->s_last); if (cmp_psn(wqe->lpsn, qp->s_sending_psn) >= 0 && cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0) break; trdma_clean_swqe(qp, wqe); rvt_qp_wqe_unreserve(qp, wqe); - s_last = qp->s_last; - trace_hfi1_qp_send_completion(qp, wqe, s_last); - if (++s_last >= qp->s_size) - s_last = 0; - qp->s_last = s_last; - /* see post_send() */ - barrier(); - rvt_put_qp_swqe(qp, wqe); - rvt_qp_swqe_complete(qp, + trace_hfi1_qp_send_completion(qp, wqe, qp->s_last); + rvt_qp_complete_swqe(qp, wqe, ib_hfi1_wc_opcode[wqe->wr.opcode], IB_WC_SUCCESS); @@ -1890,19 +1881,10 @@ struct rvt_swqe *do_rc_completion(struct rvt_qp *qp, trace_hfi1_rc_completion(qp, wqe->lpsn); if (cmp_psn(wqe->lpsn, qp->s_sending_psn) < 0 || cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) > 0) { - u32 s_last; - trdma_clean_swqe(qp, wqe); - rvt_put_qp_swqe(qp, wqe); rvt_qp_wqe_unreserve(qp, wqe); - s_last = qp->s_last; - trace_hfi1_qp_send_completion(qp, wqe, s_last); - if (++s_last >= qp->s_size) - s_last = 0; - qp->s_last = s_last; - /* see post_send() */ - barrier(); - rvt_qp_swqe_complete(qp, + trace_hfi1_qp_send_completion(qp, wqe, qp->s_last); + rvt_qp_complete_swqe(qp, wqe, ib_hfi1_wc_opcode[wqe->wr.opcode], IB_WC_SUCCESS); diff --git a/drivers/infiniband/hw/qib/qib_rc.c b/drivers/infiniband/hw/qib/qib_rc.c index 2ac4c67f5ba1a..8d9a94d6f6856 100644 --- a/drivers/infiniband/hw/qib/qib_rc.c +++ b/drivers/infiniband/hw/qib/qib_rc.c @@ -921,20 +921,11 @@ void qib_rc_send_complete(struct rvt_qp *qp, struct ib_header *hdr) rvt_add_retry_timer(qp); while (qp->s_last != qp->s_acked) { - u32 s_last; - wqe = rvt_get_swqe_ptr(qp, qp->s_last); if (qib_cmp24(wqe->lpsn, qp->s_sending_psn) >= 0 && qib_cmp24(qp->s_sending_psn, qp->s_sending_hpsn) <= 0) break; - s_last = qp->s_last; - if (++s_last >= qp->s_size) - s_last = 0; - qp->s_last = s_last; - /* see post_send() */ - barrier(); - rvt_put_qp_swqe(qp, wqe); - rvt_qp_swqe_complete(qp, + rvt_qp_complete_swqe(qp, wqe, ib_qib_wc_opcode[wqe->wr.opcode], IB_WC_SUCCESS); @@ -972,21 +963,12 @@ static struct rvt_swqe *do_rc_completion(struct rvt_qp *qp, * is finished. */ if (qib_cmp24(wqe->lpsn, qp->s_sending_psn) < 0 || - qib_cmp24(qp->s_sending_psn, qp->s_sending_hpsn) > 0) { - u32 s_last; - - rvt_put_qp_swqe(qp, wqe); - s_last = qp->s_last; - if (++s_last >= qp->s_size) - s_last = 0; - qp->s_last = s_last; - /* see post_send() */ - barrier(); - rvt_qp_swqe_complete(qp, + qib_cmp24(qp->s_sending_psn, qp->s_sending_hpsn) > 0) + rvt_qp_complete_swqe(qp, wqe, ib_qib_wc_opcode[wqe->wr.opcode], IB_WC_SUCCESS); - } else + else this_cpu_inc(*ibp->rvp.rc_delayed_comp); qp->s_retry = qp->s_retry_cnt; diff --git a/drivers/infiniband/sw/rdmavt/qp.c b/drivers/infiniband/sw/rdmavt/qp.c index c5a50614a6c63..cb9e171d7e7bf 100644 --- a/drivers/infiniband/sw/rdmavt/qp.c +++ b/drivers/infiniband/sw/rdmavt/qp.c @@ -1856,10 +1856,9 @@ static inline int rvt_qp_is_avail( /* see rvt_qp_wqe_unreserve() */ smp_mb__before_atomic(); - reserved_used = atomic_read(&qp->s_reserved_used); if (unlikely(reserved_op)) { /* see rvt_qp_wqe_unreserve() */ - smp_mb__before_atomic(); + reserved_used = atomic_read(&qp->s_reserved_used); if (reserved_used >= rdi->dparms.reserved_operations) return -ENOMEM; return 0; @@ -1867,14 +1866,13 @@ static inline int rvt_qp_is_avail( /* non-reserved operations */ if (likely(qp->s_avail)) return 0; - slast = READ_ONCE(qp->s_last); + /* See rvt_qp_complete_swqe() */ + slast = smp_load_acquire(&qp->s_last); if (qp->s_head >= slast) avail = qp->s_size - (qp->s_head - slast); else avail = slast - qp->s_head; - /* see rvt_qp_wqe_unreserve() */ - smp_mb__before_atomic(); reserved_used = atomic_read(&qp->s_reserved_used); avail = avail - 1 - (rdi->dparms.reserved_operations - reserved_used); @@ -2667,27 +2665,16 @@ void rvt_send_complete(struct rvt_qp *qp, struct rvt_swqe *wqe, enum ib_wc_status status) { u32 old_last, last; - struct rvt_dev_info *rdi = ib_to_rvt(qp->ibqp.device); + struct rvt_dev_info *rdi; if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_OR_FLUSH_SEND)) return; + rdi = ib_to_rvt(qp->ibqp.device); - last = qp->s_last; - old_last = last; - trace_rvt_qp_send_completion(qp, wqe, last); - if (++last >= qp->s_size) - last = 0; - trace_rvt_qp_send_completion(qp, wqe, last); - qp->s_last = last; - /* See post_send() */ - barrier(); - rvt_put_qp_swqe(qp, wqe); - - rvt_qp_swqe_complete(qp, - wqe, - rdi->wc_opcode[wqe->wr.opcode], - status); - + old_last = qp->s_last; + trace_rvt_qp_send_completion(qp, wqe, old_last); + last = rvt_qp_complete_swqe(qp, wqe, rdi->wc_opcode[wqe->wr.opcode], + status); if (qp->s_acked == old_last) qp->s_acked = last; if (qp->s_cur == old_last) diff --git a/include/rdma/rdmavt_qp.h b/include/rdma/rdmavt_qp.h index 6014f17669071..84d0f36afc2f7 100644 --- a/include/rdma/rdmavt_qp.h +++ b/include/rdma/rdmavt_qp.h @@ -565,42 +565,6 @@ static inline void rvt_qp_wqe_unreserve( extern const enum ib_wc_opcode ib_rvt_wc_opcode[]; -/** - * rvt_qp_swqe_complete() - insert send completion - * @qp - the qp - * @wqe - the send wqe - * @status - completion status - * - * Insert a send completion into the completion - * queue if the qp indicates it should be done. - * - * See IBTA 10.7.3.1 for info on completion - * control. - */ -static inline void rvt_qp_swqe_complete( - struct rvt_qp *qp, - struct rvt_swqe *wqe, - enum ib_wc_opcode opcode, - enum ib_wc_status status) -{ - if (unlikely(wqe->wr.send_flags & RVT_SEND_RESERVE_USED)) - return; - if (!(qp->s_flags & RVT_S_SIGNAL_REQ_WR) || - (wqe->wr.send_flags & IB_SEND_SIGNALED) || - status != IB_WC_SUCCESS) { - struct ib_wc wc; - - memset(&wc, 0, sizeof(wc)); - wc.wr_id = wqe->wr.wr_id; - wc.status = status; - wc.opcode = opcode; - wc.qp = &qp->ibqp; - wc.byte_len = wqe->length; - rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.send_cq), &wc, - status != IB_WC_SUCCESS); - } -} - /* * Compare the lower 24 bits of the msn values. * Returns an integer <, ==, or > than zero. -- 2.20.1
