[PATCH 3.16 242/366] iw_cxgb4: Atomically flush per QP HW CQEs

Ben Hutchings
2018-10-14T15:25:41Z

From: Bharat Potnuri <bharat@chelsio.com>

commit 2df19e19ae90d94fd8724083f161f368a2797537 upstream.

When a CQ is shared by multiple QPs, c4iw_flush_hw_cq() needs to acquire
corresponding QP lock before moving the CQEs into its corresponding SW
queue and accessing the SQ contents for completing a WR.
Ignore CQEs if corresponding QP is already flushed.

Signed-off-by: Potnuri Bharat Teja <bharat@chelsio.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/infiniband/hw/cxgb4/cq.c | 11 ++++++++++-
drivers/infiniband/hw/cxgb4/iw_cxgb4.h | 2 +-
drivers/infiniband/hw/cxgb4/qp.c | 4 ++--
3 files changed, 13 insertions(+), 4 deletions(-)

--- a/drivers/infiniband/hw/cxgb4/cq.c
+++ b/drivers/infiniband/hw/cxgb4/cq.c
@@ -331,7 +331,7 @@ static void advance_oldest_read(struct t
* Deal with out-of-order and/or completions that complete
* prior unsignalled WRs.
*/
-void c4iw_flush_hw_cq(struct c4iw_cq *chp)
+void c4iw_flush_hw_cq(struct c4iw_cq *chp, struct c4iw_qp *flush_qhp)
{
struct t4_cqe *hw_cqe, *swcqe, read_cqe;
struct c4iw_qp *qhp;
@@ -355,6 +355,13 @@ void c4iw_flush_hw_cq(struct c4iw_cq *ch
if (qhp == NULL)
goto next_cqe;

+ if (flush_qhp != qhp) {
+ spin_lock(&qhp->lock);
+
+ if (qhp->wq.flushed == 1)
+ goto next_cqe;
+ }
+
if (CQE_OPCODE(hw_cqe) == FW_RI_TERMINATE)
goto next_cqe;

@@ -406,6 +413,8 @@ void c4iw_flush_hw_cq(struct c4iw_cq *ch
next_cqe:
t4_hwcq_consume(&chp->cq);
ret = t4_next_hw_cqe(&chp->cq, &hw_cqe);
+ if (qhp && flush_qhp != qhp)
+ spin_unlock(&qhp->lock);
}
}

--- a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
+++ b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
@@ -977,7 +977,7 @@ void c4iw_pblpool_free(struct c4iw_rdev
u32 c4iw_ocqp_pool_alloc(struct c4iw_rdev *rdev, int size);
void c4iw_ocqp_pool_free(struct c4iw_rdev *rdev, u32 addr, int size);
int c4iw_ofld_send(struct c4iw_rdev *rdev, struct sk_buff *skb);
-void c4iw_flush_hw_cq(struct c4iw_cq *chp);
+void c4iw_flush_hw_cq(struct c4iw_cq *chp, struct c4iw_qp *flush_qhp);
void c4iw_count_rcqes(struct t4_cq *cq, struct t4_wq *wq, int *count);
int c4iw_ep_disconnect(struct c4iw_ep *ep, int abrupt, gfp_t gfp);
int c4iw_flush_rq(struct t4_wq *wq, struct t4_cq *cq, int count);
--- a/drivers/infiniband/hw/cxgb4/qp.c
+++ b/drivers/infiniband/hw/cxgb4/qp.c
@@ -1082,7 +1082,7 @@ static void __flush_qp(struct c4iw_qp *q
}
qhp->wq.flushed = 1;

- c4iw_flush_hw_cq(rchp);
+ c4iw_flush_hw_cq(rchp, qhp);
c4iw_count_rcqes(&rchp->cq, &qhp->wq, &count);
flushed = c4iw_flush_rq(&qhp->wq, &rchp->cq, count);
spin_unlock(&qhp->lock);
@@ -1097,7 +1097,7 @@ static void __flush_qp(struct c4iw_qp *q
spin_lock_irqsave(&schp->lock, flag);
spin_lock(&qhp->lock);
if (schp != rchp)
- c4iw_flush_hw_cq(schp);
+ c4iw_flush_hw_cq(schp, qhp);
flushed = c4iw_flush_sq(qhp);
spin_unlock(&qhp->lock);
spin_unlock_irqrestore(&schp->lock, flag);