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authorKumar Sanghvi <kumaras@chelsio.com>2011-10-24 21:20:22 +0530
committerRoland Dreier <roland@purestorage.com>2011-10-31 11:33:17 -0700
commitf7cc25d018f1e9af6767ee7774bbe83452e9fdf4 (patch)
tree43d10d7038f8295b4ad92e938b0c705db5ce58b3 /drivers/infiniband/hw/cxgb3/iwch_qp.c
parent976d167615b64e14bc1491ca51d424e2ba9a5e84 (diff)
downloadblackbird-op-linux-f7cc25d018f1e9af6767ee7774bbe83452e9fdf4.tar.gz
blackbird-op-linux-f7cc25d018f1e9af6767ee7774bbe83452e9fdf4.zip
RDMA/cxgb3: Serialize calls to CQ's comp_handler
iw_cxgb3 has a potential problem where a CQ's comp_handler can get called simultaneously from different places in iw_cxgb3 driver. This does not comply with Documentation/infiniband/core_locking.txt, which states that at a given point of time, there should be only one callback per CQ should be active. Such problem was reported by Parav Pandit <Parav.Pandit@Emulex.Com> for iw_cxgb4 driver. Based on discussion between Parav Pandit and Steve Wise, this patch fixes the above problem by serializing the calls to a CQ's comp_handler using a spin_lock. Signed-off-by: Kumar Sanghvi <kumaras@chelsio.com> Acked-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
Diffstat (limited to 'drivers/infiniband/hw/cxgb3/iwch_qp.c')
-rw-r--r--drivers/infiniband/hw/cxgb3/iwch_qp.c14
1 files changed, 12 insertions, 2 deletions
diff --git a/drivers/infiniband/hw/cxgb3/iwch_qp.c b/drivers/infiniband/hw/cxgb3/iwch_qp.c
index ecd313f359a4..bea5839d89ee 100644
--- a/drivers/infiniband/hw/cxgb3/iwch_qp.c
+++ b/drivers/infiniband/hw/cxgb3/iwch_qp.c
@@ -822,8 +822,11 @@ static void __flush_qp(struct iwch_qp *qhp, struct iwch_cq *rchp,
flushed = cxio_flush_rq(&qhp->wq, &rchp->cq, count);
spin_unlock(&qhp->lock);
spin_unlock_irqrestore(&rchp->lock, *flag);
- if (flushed)
+ if (flushed) {
+ spin_lock_irqsave(&rchp->comp_handler_lock, *flag);
(*rchp->ibcq.comp_handler)(&rchp->ibcq, rchp->ibcq.cq_context);
+ spin_unlock_irqrestore(&rchp->comp_handler_lock, *flag);
+ }
/* locking hierarchy: cq lock first, then qp lock. */
spin_lock_irqsave(&schp->lock, *flag);
@@ -833,8 +836,11 @@ static void __flush_qp(struct iwch_qp *qhp, struct iwch_cq *rchp,
flushed = cxio_flush_sq(&qhp->wq, &schp->cq, count);
spin_unlock(&qhp->lock);
spin_unlock_irqrestore(&schp->lock, *flag);
- if (flushed)
+ if (flushed) {
+ spin_lock_irqsave(&schp->comp_handler_lock, *flag);
(*schp->ibcq.comp_handler)(&schp->ibcq, schp->ibcq.cq_context);
+ spin_unlock_irqrestore(&schp->comp_handler_lock, *flag);
+ }
/* deref */
if (atomic_dec_and_test(&qhp->refcnt))
@@ -853,11 +859,15 @@ static void flush_qp(struct iwch_qp *qhp, unsigned long *flag)
if (qhp->ibqp.uobject) {
cxio_set_wq_in_error(&qhp->wq);
cxio_set_cq_in_error(&rchp->cq);
+ spin_lock_irqsave(&rchp->comp_handler_lock, *flag);
(*rchp->ibcq.comp_handler)(&rchp->ibcq, rchp->ibcq.cq_context);
+ spin_unlock_irqrestore(&rchp->comp_handler_lock, *flag);
if (schp != rchp) {
cxio_set_cq_in_error(&schp->cq);
+ spin_lock_irqsave(&schp->comp_handler_lock, *flag);
(*schp->ibcq.comp_handler)(&schp->ibcq,
schp->ibcq.cq_context);
+ spin_unlock_irqrestore(&schp->comp_handler_lock, *flag);
}
return;
}
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