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authorCornelia Huck <cohuck@redhat.com>2018-04-20 10:24:04 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2018-04-23 07:57:17 +0200
commit3368e547c52b96586f0edf9657ca12b94d8e61a7 (patch)
tree24c6dc9eb7f07f66e293000237751639548a2833 /drivers/s390
parent2317b07d05d2b136eb4dc9609807c9111bda3b2a (diff)
downloadlinux-3368e547c52b96586f0edf9657ca12b94d8e61a7.tar.bz2
vfio: ccw: process ssch with interrupts disabled
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 while holding the subchannel lock until after we're done with our processing. Cc: stable@vger.kernel.org #v4.12+ Reviewed-by: Dong Jia Shi <bjsdjshi@linux.ibm.com> Acked-by: Halil Pasic <pasic@linux.vnet.ibm.com> Acked-by: Pierre Morel <pmorel@linux.vnet.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390')
-rw-r--r--drivers/s390/cio/vfio_ccw_fsm.c19
1 files 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,