From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755050AbeDMOFO (ORCPT ); Fri, 13 Apr 2018 10:05:14 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:60766 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754086AbeDMOFN (ORCPT ); Fri, 13 Apr 2018 10:05:13 -0400 From: Cornelia Huck To: Dong Jia Shi , Halil Pasic Cc: linux-s390@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Cornelia Huck Subject: [PATCH] vfio-ccw: process ssch with interrupts disabled Date: Fri, 13 Apr 2018 16:05:09 +0200 Message-Id: <20180413140509.9042-1-cohuck@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When we call ssch, an interrupt might already be pending once we return from the START SUBCHANNEL instruction. Therefore we need to make sure interrupts are disabled until after we're done with our processing. Note that the subchannel lock is the same as the ccwdevice lock that is mentioned in the documentation for ccw_device_start() and friends. Signed-off-by: Cornelia Huck --- drivers/s390/cio/vfio_ccw_fsm.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c index ff6963ad6e39..3c800642134e 100644 --- a/drivers/s390/cio/vfio_ccw_fsm.c +++ b/drivers/s390/cio/vfio_ccw_fsm.c @@ -20,12 +20,12 @@ static int fsm_io_helper(struct vfio_ccw_private *private) int ccode; __u8 lpm; unsigned long flags; + int ret; sch = private->sch; spin_lock_irqsave(sch->lock, flags); private->state = VFIO_CCW_STATE_BUSY; - spin_unlock_irqrestore(sch->lock, flags); orb = cp_get_orb(&private->cp, (u32)(addr_t)sch, sch->lpm); @@ -38,10 +38,12 @@ static int fsm_io_helper(struct vfio_ccw_private *private) * Initialize device status information */ sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND; - return 0; + ret = 0; + break; case 1: /* Status pending */ case 2: /* Busy */ - return -EBUSY; + ret = -EBUSY; + break; case 3: /* Device/path not operational */ { lpm = orb->cmd.lpm; @@ -51,13 +53,16 @@ static int fsm_io_helper(struct vfio_ccw_private *private) sch->lpm = 0; if (cio_update_schib(sch)) - return -ENODEV; - - return sch->lpm ? -EACCES : -ENODEV; + ret = -ENODEV; + else + ret = sch->lpm ? -EACCES : -ENODEV; + break; } default: - return ccode; + ret = ccode; } + spin_unlock_irqrestore(sch->lock, flags); + return ret; } static void fsm_notoper(struct vfio_ccw_private *private, -- 2.14.3