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authorKumar Sanghvi <kumaras@chelsio.com>2011-10-24 19:50:22 +0400
committerRoland Dreier <roland@purestorage.com>2011-10-31 22:33:17 +0400
commitf7cc25d018f1e9af6767ee7774bbe83452e9fdf4 (patch)
tree43d10d7038f8295b4ad92e938b0c705db5ce58b3 /drivers/infiniband/hw
parent976d167615b64e14bc1491ca51d424e2ba9a5e84 (diff)
downloadlinux-f7cc25d018f1e9af6767ee7774bbe83452e9fdf4.tar.xz
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')
-rw-r--r--drivers/infiniband/hw/cxgb3/iwch_ev.c6
-rw-r--r--drivers/infiniband/hw/cxgb3/iwch_provider.c1
-rw-r--r--drivers/infiniband/hw/cxgb3/iwch_provider.h1
-rw-r--r--drivers/infiniband/hw/cxgb3/iwch_qp.c14
4 files changed, 20 insertions, 2 deletions
diff --git a/drivers/infiniband/hw/cxgb3/iwch_ev.c b/drivers/infiniband/hw/cxgb3/iwch_ev.c
index 71e0d845da3d..abcc9e76962b 100644
--- a/drivers/infiniband/hw/cxgb3/iwch_ev.c
+++ b/drivers/infiniband/hw/cxgb3/iwch_ev.c
@@ -46,6 +46,7 @@ static void post_qp_event(struct iwch_dev *rnicp, struct iwch_cq *chp,
struct ib_event event;
struct iwch_qp_attributes attrs;
struct iwch_qp *qhp;
+ unsigned long flag;
spin_lock(&rnicp->lock);
qhp = get_qhp(rnicp, CQE_QPID(rsp_msg->cqe));
@@ -94,7 +95,9 @@ static void post_qp_event(struct iwch_dev *rnicp, struct iwch_cq *chp,
if (qhp->ibqp.event_handler)
(*qhp->ibqp.event_handler)(&event, qhp->ibqp.qp_context);
+ spin_lock_irqsave(&chp->comp_handler_lock, flag);
(*chp->ibcq.comp_handler)(&chp->ibcq, chp->ibcq.cq_context);
+ spin_unlock_irqrestore(&chp->comp_handler_lock, flag);
if (atomic_dec_and_test(&qhp->refcnt))
wake_up(&qhp->wait);
@@ -107,6 +110,7 @@ void iwch_ev_dispatch(struct cxio_rdev *rdev_p, struct sk_buff *skb)
struct iwch_cq *chp;
struct iwch_qp *qhp;
u32 cqid = RSPQ_CQID(rsp_msg);
+ unsigned long flag;
rnicp = (struct iwch_dev *) rdev_p->ulp;
spin_lock(&rnicp->lock);
@@ -170,7 +174,9 @@ void iwch_ev_dispatch(struct cxio_rdev *rdev_p, struct sk_buff *skb)
*/
if (qhp->ep && SQ_TYPE(rsp_msg->cqe))
dst_confirm(qhp->ep->dst);
+ spin_lock_irqsave(&chp->comp_handler_lock, flag);
(*chp->ibcq.comp_handler)(&chp->ibcq, chp->ibcq.cq_context);
+ spin_unlock_irqrestore(&chp->comp_handler_lock, flag);
break;
case TPT_ERR_STAG:
diff --git a/drivers/infiniband/hw/cxgb3/iwch_provider.c b/drivers/infiniband/hw/cxgb3/iwch_provider.c
index c7d9411f2954..37c224fc3ad9 100644
--- a/drivers/infiniband/hw/cxgb3/iwch_provider.c
+++ b/drivers/infiniband/hw/cxgb3/iwch_provider.c
@@ -190,6 +190,7 @@ static struct ib_cq *iwch_create_cq(struct ib_device *ibdev, int entries, int ve
chp->rhp = rhp;
chp->ibcq.cqe = 1 << chp->cq.size_log2;
spin_lock_init(&chp->lock);
+ spin_lock_init(&chp->comp_handler_lock);
atomic_set(&chp->refcnt, 1);
init_waitqueue_head(&chp->wait);
if (insert_handle(rhp, &rhp->cqidr, chp, chp->cq.cqid)) {
diff --git a/drivers/infiniband/hw/cxgb3/iwch_provider.h b/drivers/infiniband/hw/cxgb3/iwch_provider.h
index 9a342c9b220d..87c14b0c5ac0 100644
--- a/drivers/infiniband/hw/cxgb3/iwch_provider.h
+++ b/drivers/infiniband/hw/cxgb3/iwch_provider.h
@@ -103,6 +103,7 @@ struct iwch_cq {
struct iwch_dev *rhp;
struct t3_cq cq;
spinlock_t lock;
+ spinlock_t comp_handler_lock;
atomic_t refcnt;
wait_queue_head_t wait;
u32 __user *user_rptr_addr;
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;
}