diff options
| author | Kumar Sanghvi <kumaras@chelsio.com> | 2011-10-24 21:20:21 +0530 |
|---|---|---|
| committer | Roland Dreier <roland@purestorage.com> | 2011-10-31 11:34:53 -0700 |
| commit | 581bbe2cd0694a935e0c3ccd7f011e10094f1df6 (patch) | |
| tree | 38e536efa0d05d76964b09836def2210a00b41b5 /drivers/infiniband/hw/cxgb4/qp.c | |
| parent | e14d62c05c0b8eff61c6fd46b4a78fb27c8cf38b (diff) | |
RDMA/cxgb4: Serialize calls to CQ's comp_handler
Commit 01e7da6ba53c ("RDMA/cxgb4: Make sure flush CQ entries are
collected on connection close") introduced a potential problem where a
CQ's comp_handler can get called simultaneously from different places
in the iw_cxgb4 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.
This problem was reported by Parav Pandit <Parav.Pandit@Emulex.Com>.
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.
Reported-by: Parav Pandit <Parav.Pandit@Emulex.Com>
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/cxgb4/qp.c')
| -rw-r--r-- | drivers/infiniband/hw/cxgb4/qp.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/infiniband/hw/cxgb4/qp.c b/drivers/infiniband/hw/cxgb4/qp.c index 892fa7c6d310..62c7262a9eb3 100644 --- a/drivers/infiniband/hw/cxgb4/qp.c +++ b/drivers/infiniband/hw/cxgb4/qp.c @@ -941,8 +941,11 @@ static void __flush_qp(struct c4iw_qp *qhp, struct c4iw_cq *rchp, flushed = c4iw_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); @@ -952,13 +955,17 @@ static void __flush_qp(struct c4iw_qp *qhp, struct c4iw_cq *rchp, flushed = c4iw_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); + } } static void flush_qp(struct c4iw_qp *qhp) { struct c4iw_cq *rchp, *schp; + unsigned long flag; rchp = get_chp(qhp->rhp, qhp->attr.rcq); schp = get_chp(qhp->rhp, qhp->attr.scq); @@ -966,11 +973,15 @@ static void flush_qp(struct c4iw_qp *qhp) if (qhp->ibqp.uobject) { t4_set_wq_in_error(&qhp->wq); t4_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) { t4_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; } |