From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrea Parri Subject: [PATCH 5/5] IB/hfi1: Fix improper uses of smp_mb__before_atomic() Date: Mon, 29 Apr 2019 22:15:01 +0200 Message-ID: <1556568902-12464-6-git-send-email-andrea.parri@amarulasolutions.com> References: <1556568902-12464-1-git-send-email-andrea.parri@amarulasolutions.com> Return-path: In-Reply-To: <1556568902-12464-1-git-send-email-andrea.parri@amarulasolutions.com> Sender: stable-owner@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: Andrea Parri , stable@vger.kernel.org, Dennis Dalessandro , Mike Marciniszyn , Doug Ledford , Jason Gunthorpe , linux-rdma@vger.kernel.org List-Id: linux-rdma@vger.kernel.org This barrier only applies to the read-modify-write operations; in particular, it does not apply to the atomic_read() primitive. Replace the barrier with an smp_mb(). Fixes: 856cc4c237add ("IB/hfi1: Add the capability for reserved operations") Cc: stable@vger.kernel.org Reported-by: "Paul E. McKenney" Reported-by: Peter Zijlstra Signed-off-by: Andrea Parri Cc: Dennis Dalessandro Cc: Mike Marciniszyn Cc: Doug Ledford Cc: Jason Gunthorpe Cc: linux-rdma@vger.kernel.org --- drivers/infiniband/sw/rdmavt/qp.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/infiniband/sw/rdmavt/qp.c b/drivers/infiniband/sw/rdmavt/qp.c index a34b9a2a32b60..b64fd151d31fb 100644 --- a/drivers/infiniband/sw/rdmavt/qp.c +++ b/drivers/infiniband/sw/rdmavt/qp.c @@ -1863,11 +1863,11 @@ static inline int rvt_qp_is_avail( u32 reserved_used; /* see rvt_qp_wqe_unreserve() */ - smp_mb__before_atomic(); + smp_mb(); reserved_used = atomic_read(&qp->s_reserved_used); if (unlikely(reserved_op)) { /* see rvt_qp_wqe_unreserve() */ - smp_mb__before_atomic(); + smp_mb(); if (reserved_used >= rdi->dparms.reserved_operations) return -ENOMEM; return 0; @@ -1882,7 +1882,7 @@ static inline int rvt_qp_is_avail( avail = slast - qp->s_head; /* see rvt_qp_wqe_unreserve() */ - smp_mb__before_atomic(); + smp_mb(); reserved_used = atomic_read(&qp->s_reserved_used); avail = avail - 1 - (rdi->dparms.reserved_operations - reserved_used); -- 2.7.4