IB/ipath: Fix many locking issues when switching to error state

The send DMA hardware queue voided a number of prior assumptions about
when a send is complete which led to completions being generated out of
order.  There were also a number of locking issues when switching the QP
to the error or reset states, and we implement the IB_QPS_SQD state.

Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 38 insertions, 19 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_uc.c b/drivers/infiniband/hw/ipath/ipath_uc.c
index bfe8926b551..7fd18e83390 100644
--- a/drivers/infiniband/hw/ipath/ipath_uc.c
+++ b/drivers/infiniband/hw/ipath/ipath_uc.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2006, 2007 QLogic Corporation. All rights reserved.
+ * Copyright (c) 2006, 2007, 2008 QLogic Corporation. All rights reserved.
  * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
  *
  * This software is available to you under a choice of one of two
@@ -47,14 +47,30 @@ int ipath_make_uc_req(struct ipath_qp *qp)
 {
         struct ipath_other_headers *ohdr;
         struct ipath_swqe *wqe;
+        unsigned long flags;
         u32 hwords;
         u32 bth0;
         u32 len;
         u32 pmtu = ib_mtu_enum_to_int(qp->path_mtu);
         int ret = 0;
 
-        if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_SEND_OK))
+        spin_lock_irqsave(&qp->s_lock, flags);
+
+        if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_SEND_OK)) {
+                if (!(ib_ipath_state_ops[qp->state] & IPATH_FLUSH_SEND))
+                        goto bail;
+                /* We are in the error state, flush the work request. */
+                if (qp->s_last == qp->s_head)
+                        goto bail;
+                /* If DMAs are in progress, we can't flush immediately. */
+                if (atomic_read(&qp->s_dma_busy)) {
+                        qp->s_flags |= IPATH_S_WAIT_DMA;
+                        goto bail;
+                }
+                wqe = get_swqe_ptr(qp, qp->s_last);
+                ipath_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR);
                 goto done;
+        }
 
         ohdr = &qp->s_hdr.u.oth;
         if (qp->remote_ah_attr.ah_flags & IB_AH_GRH)
@@ -69,9 +85,12 @@ int ipath_make_uc_req(struct ipath_qp *qp)
         qp->s_wqe = NULL;
         switch (qp->s_state) {
         default:
+                if (!(ib_ipath_state_ops[qp->state] &
+                    IPATH_PROCESS_NEXT_SEND_OK))
+                        goto bail;
                 /* Check if send work queue is empty. */
                 if (qp->s_cur == qp->s_head)
-                        goto done;
+                        goto bail;
                 /*
                  * Start a new request.
                  */
@@ -134,7 +153,7 @@ int ipath_make_uc_req(struct ipath_qp *qp)
                         break;
 
                 default:
-                        goto done;
+                        goto bail;
                 }
                 break;
 
@@ -194,9 +213,14 @@ int ipath_make_uc_req(struct ipath_qp *qp)
         ipath_make_ruc_header(to_idev(qp->ibqp.device),
                               qp, ohdr, bth0 | (qp->s_state << 24),
                               qp->s_next_psn++ & IPATH_PSN_MASK);
+done:
         ret = 1;
+        goto unlock;
 
-done:
+bail:
+        qp->s_flags &= ~IPATH_S_BUSY;
+unlock:
+        spin_unlock_irqrestore(&qp->s_lock, flags);
         return ret;
 }
 
@@ -258,8 +282,7 @@ void ipath_uc_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
          */
         opcode = be32_to_cpu(ohdr->bth[0]) >> 24;
 
-        wc.imm_data = 0;
-        wc.wc_flags = 0;
+        memset(&wc, 0, sizeof wc);
 
         /* Compare the PSN verses the expected PSN. */
         if (unlikely(ipath_cmp24(psn, qp->r_psn) != 0)) {
@@ -322,8 +345,8 @@ void ipath_uc_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
         case OP(SEND_ONLY):
         case OP(SEND_ONLY_WITH_IMMEDIATE):
         send_first:
-                if (qp->r_reuse_sge) {
-                        qp->r_reuse_sge = 0;
+                if (qp->r_flags & IPATH_R_REUSE_SGE) {
+                        qp->r_flags &= ~IPATH_R_REUSE_SGE;
                         qp->r_sge = qp->s_rdma_read_sge;
                 } else if (!ipath_get_rwqe(qp, 0)) {
                         dev->n_pkt_drops++;
@@ -340,13 +363,13 @@ void ipath_uc_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
         case OP(SEND_MIDDLE):
                 /* Check for invalid length PMTU or posted rwqe len. */
                 if (unlikely(tlen != (hdrsize + pmtu + 4))) {
-                        qp->r_reuse_sge = 1;
+                        qp->r_flags |= IPATH_R_REUSE_SGE;
                         dev->n_pkt_drops++;
                         goto done;
                 }
                 qp->r_rcv_len += pmtu;
                 if (unlikely(qp->r_rcv_len > qp->r_len)) {
-                        qp->r_reuse_sge = 1;
+                        qp->r_flags |= IPATH_R_REUSE_SGE;
                         dev->n_pkt_drops++;
                         goto done;
                 }
@@ -372,7 +395,7 @@ void ipath_uc_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
                 /* Check for invalid length. */
                 /* XXX LAST len should be >= 1 */
                 if (unlikely(tlen < (hdrsize + pad + 4))) {
-                        qp->r_reuse_sge = 1;
+                        qp->r_flags |= IPATH_R_REUSE_SGE;
                         dev->n_pkt_drops++;
                         goto done;
                 }
@@ -380,7 +403,7 @@ void ipath_uc_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
                 tlen -= (hdrsize + pad + 4);
                 wc.byte_len = tlen + qp->r_rcv_len;
                 if (unlikely(wc.byte_len > qp->r_len)) {
-                        qp->r_reuse_sge = 1;
+                        qp->r_flags |= IPATH_R_REUSE_SGE;
                         dev->n_pkt_drops++;
                         goto done;
                 }
@@ -390,14 +413,10 @@ void ipath_uc_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
                 wc.wr_id = qp->r_wr_id;
                 wc.status = IB_WC_SUCCESS;
                 wc.opcode = IB_WC_RECV;
-                wc.vendor_err = 0;
                 wc.qp = &qp->ibqp;
                 wc.src_qp = qp->remote_qpn;
-                wc.pkey_index = 0;
                 wc.slid = qp->remote_ah_attr.dlid;
                 wc.sl = qp->remote_ah_attr.sl;
-                wc.dlid_path_bits = 0;
-                wc.port_num = 0;
                 /* Signal completion event if the solicited bit is set. */
                 ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
                                (ohdr->bth[0] &
@@ -488,8 +507,8 @@ void ipath_uc_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
                         dev->n_pkt_drops++;
                         goto done;
                 }
-                if (qp->r_reuse_sge)
-                        qp->r_reuse_sge = 0;
+                if (qp->r_flags & IPATH_R_REUSE_SGE)
+                        qp->r_flags &= ~IPATH_R_REUSE_SGE;
                 else if (!ipath_get_rwqe(qp, 1)) {
                         dev->n_pkt_drops++;
                         goto done;