RDMA/nes: Clean out CQ completions when QP is destroyed

When a QP is destroyed, unprocessed CQ entries could still reference
the QP.  This change zeroes the context value at QP destroy time.  By
skipping over cqe's with a zero context, poll_cq no longer processes a
cqe for a destroyed QP.

Signed-off-by: Don Wood <donald.e.wood@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 80 insertions, 39 deletions

diff --git a/drivers/infiniband/hw/nes/nes_verbs.c b/drivers/infiniband/hw/nes/nes_verbs.c
index 21e0fd336cf7..c6b5873416eb 100644
--- a/drivers/infiniband/hw/nes/nes_verbs.c
+++ b/drivers/infiniband/hw/nes/nes_verbs.c
@@ -1506,12 +1506,45 @@ static struct ib_qp *nes_create_qp(struct ib_pd *ibpd,
 
 
 /**
+ * nes_clean_cq
+ */
+static void nes_clean_cq(struct nes_qp *nesqp, struct nes_cq *nescq)
+{
+        u32 cq_head;
+        u32 lo;
+        u32 hi;
+        u64 u64temp;
+        unsigned long flags = 0;
+
+        spin_lock_irqsave(&nescq->lock, flags);
+
+        cq_head = nescq->hw_cq.cq_head;
+        while (le32_to_cpu(nescq->hw_cq.cq_vbase[cq_head].cqe_words[NES_CQE_OPCODE_IDX]) & NES_CQE_VALID) {
+                rmb();
+                lo = le32_to_cpu(nescq->hw_cq.cq_vbase[cq_head].cqe_words[NES_CQE_COMP_COMP_CTX_LOW_IDX]);
+                hi = le32_to_cpu(nescq->hw_cq.cq_vbase[cq_head].cqe_words[NES_CQE_COMP_COMP_CTX_HIGH_IDX]);
+                u64temp = (((u64)hi) << 32) | ((u64)lo);
+                u64temp &= ~(NES_SW_CONTEXT_ALIGN-1);
+                if (u64temp == (u64)(unsigned long)nesqp) {
+                        /* Zero the context value so cqe will be ignored */
+                        nescq->hw_cq.cq_vbase[cq_head].cqe_words[NES_CQE_COMP_COMP_CTX_LOW_IDX] = 0;
+                        nescq->hw_cq.cq_vbase[cq_head].cqe_words[NES_CQE_COMP_COMP_CTX_HIGH_IDX] = 0;
+                }
+
+                if (++cq_head >= nescq->hw_cq.cq_size)
+                        cq_head = 0;
+        }
+
+        spin_unlock_irqrestore(&nescq->lock, flags);
+}
+
+
+/**
  * nes_destroy_qp
  */
 static int nes_destroy_qp(struct ib_qp *ibqp)
 {
         struct nes_qp *nesqp = to_nesqp(ibqp);
-        /* struct nes_vnic *nesvnic = to_nesvnic(ibqp->device); */
         struct nes_ucontext *nes_ucontext;
         struct ib_qp_attr attr;
         struct iw_cm_id *cm_id;
@@ -1548,7 +1581,6 @@ static int nes_destroy_qp(struct ib_qp *ibqp)
                         nes_debug(NES_DBG_QP, "OFA CM event_handler returned, ret=%d\n", ret);
         }
 
-
         if (nesqp->user_mode) {
                 if ((ibqp->uobject)&&(ibqp->uobject->context)) {
                         nes_ucontext = to_nesucontext(ibqp->uobject->context);
@@ -1560,6 +1592,13 @@ static int nes_destroy_qp(struct ib_qp *ibqp)
                 }
                 if (nesqp->pbl_pbase)
                         kunmap(nesqp->page);
+        } else {
+                /* Clean any pending completions from the cq(s) */
+                if (nesqp->nesscq)
+                        nes_clean_cq(nesqp, nesqp->nesscq);
+
+                if ((nesqp->nesrcq) && (nesqp->nesrcq != nesqp->nesscq))
+                        nes_clean_cq(nesqp, nesqp->nesrcq);
         }
 
         nes_rem_ref(&nesqp->ibqp);
@@ -3547,7 +3586,6 @@ static int nes_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *entry)
 {
         u64 u64temp;
         u64 wrid;
-        /* u64 u64temp; */
         unsigned long flags = 0;
         struct nes_vnic *nesvnic = to_nesvnic(ibcq->device);
         struct nes_device *nesdev = nesvnic->nesdev;
@@ -3560,7 +3598,6 @@ static int nes_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *entry)
         u32 cqe_count = 0;
         u32 wqe_index;
         u32 u32temp;
-        /* u32 counter; */
 
         nes_debug(NES_DBG_CQ, "\n");
 
@@ -3570,24 +3607,27 @@ static int nes_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *entry)
         cq_size = nescq->hw_cq.cq_size;
 
         while (cqe_count < num_entries) {
-                if (le32_to_cpu(nescq->hw_cq.cq_vbase[head].cqe_words[NES_CQE_OPCODE_IDX]) &
-                                NES_CQE_VALID) {
-                        /*
-                         * Make sure we read CQ entry contents *after*
-                         * we've checked the valid bit.
-                         */
-                        rmb();
-
-                        cqe = nescq->hw_cq.cq_vbase[head];
-                        nescq->hw_cq.cq_vbase[head].cqe_words[NES_CQE_OPCODE_IDX] = 0;
-                        u32temp = le32_to_cpu(cqe.cqe_words[NES_CQE_COMP_COMP_CTX_LOW_IDX]);
-                        wqe_index = u32temp &
-                                        (nesdev->nesadapter->max_qp_wr - 1);
-                        u32temp &= ~(NES_SW_CONTEXT_ALIGN-1);
-                        /* parse CQE, get completion context from WQE (either rq or sq */
-                        u64temp = (((u64)(le32_to_cpu(cqe.cqe_words[NES_CQE_COMP_COMP_CTX_HIGH_IDX])))<<32) |
-                                        ((u64)u32temp);
-                        nesqp = *((struct nes_qp **)&u64temp);
+                if ((le32_to_cpu(nescq->hw_cq.cq_vbase[head].cqe_words[NES_CQE_OPCODE_IDX]) &
+                                NES_CQE_VALID) == 0)
+                        break;
+
+                /*
+                 * Make sure we read CQ entry contents *after*
+                 * we've checked the valid bit.
+                 */
+                rmb();
+
+                cqe = nescq->hw_cq.cq_vbase[head];
+                nescq->hw_cq.cq_vbase[head].cqe_words[NES_CQE_OPCODE_IDX] = 0;
+                u32temp = le32_to_cpu(cqe.cqe_words[NES_CQE_COMP_COMP_CTX_LOW_IDX]);
+                wqe_index = u32temp & (nesdev->nesadapter->max_qp_wr - 1);
+                u32temp &= ~(NES_SW_CONTEXT_ALIGN-1);
+                /* parse CQE, get completion context from WQE (either rq or sq) */
+                u64temp = (((u64)(le32_to_cpu(cqe.cqe_words[NES_CQE_COMP_COMP_CTX_HIGH_IDX])))<<32) |
+                                ((u64)u32temp);
+
+                if (u64temp) {
+                        nesqp = (struct nes_qp *)(unsigned long)u64temp;
                         memset(entry, 0, sizeof *entry);
                         if (cqe.cqe_words[NES_CQE_ERROR_CODE_IDX] == 0) {
                                 entry->status = IB_WC_SUCCESS;
@@ -3601,7 +3641,7 @@ static int nes_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *entry)
                         if (le32_to_cpu(cqe.cqe_words[NES_CQE_OPCODE_IDX]) & NES_CQE_SQ) {
                                 if (nesqp->skip_lsmm) {
                                         nesqp->skip_lsmm = 0;
-                                        wq_tail = nesqp->hwqp.sq_tail++;
+                                        nesqp->hwqp.sq_tail++;
                                 }
 
                                 /* Working on a SQ Completion*/
@@ -3643,24 +3683,25 @@ static int nes_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *entry)
                                         ((u64)(le32_to_cpu(nesqp->hwqp.rq_vbase[wq_tail].wqe_words[NES_IWARP_RQ_WQE_COMP_SCRATCH_HIGH_IDX]))<<32);
                                         entry->opcode = IB_WC_RECV;
                         }
-                        entry->wr_id = wrid;
 
-                        if (++head >= cq_size)
-                                head = 0;
-                        cqe_count++;
-                        nescq->polled_completions++;
-                        if ((nescq->polled_completions > (cq_size / 2)) ||
-                                        (nescq->polled_completions == 255)) {
-                                nes_debug(NES_DBG_CQ, "CQ%u Issuing CQE Allocate since more than half of cqes"
-                                                " are pending %u of %u.\n",
-                                                nescq->hw_cq.cq_number, nescq->polled_completions, cq_size);
-                                nes_write32(nesdev->regs+NES_CQE_ALLOC,
-                                                nescq->hw_cq.cq_number | (nescq->polled_completions << 16));
-                                nescq->polled_completions = 0;
-                        }
+                        entry->wr_id = wrid;
                         entry++;
-                } else
-                        break;
+                        cqe_count++;
+                }
+
+                if (++head >= cq_size)
+                        head = 0;
+                nescq->polled_completions++;
+
+                if ((nescq->polled_completions > (cq_size / 2)) ||
+                                (nescq->polled_completions == 255)) {
+                        nes_debug(NES_DBG_CQ, "CQ%u Issuing CQE Allocate since more than half of cqes"
+                                        " are pending %u of %u.\n",
+                                        nescq->hw_cq.cq_number, nescq->polled_completions, cq_size);
+                        nes_write32(nesdev->regs+NES_CQE_ALLOC,
+                                        nescq->hw_cq.cq_number | (nescq->polled_completions << 16));
+                        nescq->polled_completions = 0;
+                }
         }
 
         if (nescq->polled_completions) {