2007-01-07 10:43:30

by Martin Schwidefsky

[permalink] [raw]
Subject: [S390] cio: use barrier() in stsch_reset.

From: Heiko Carstens <[email protected]>

[S390] cio: use barrier() in stsch_reset.

Use barrier() in stsch_reset() instead of duplicating the stsch()
inline assembly and adding "memory" to the clobberlist.
Pointed out by Chuck Ebbert.

Real fix would be to add a fixup section to the stsch() and extend the
basic program check handler so it searches the exception tables in case
of a program check.

Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>
---

drivers/s390/cio/cio.c | 12 ++++--------
1 files changed, 4 insertions(+), 8 deletions(-)

diff -urpN linux-2.6/drivers/s390/cio/cio.c linux-2.6-patched/drivers/s390/cio/cio.c
--- linux-2.6/drivers/s390/cio/cio.c 2007-01-06 15:20:12.000000000 +0100
+++ linux-2.6-patched/drivers/s390/cio/cio.c 2007-01-06 15:20:31.000000000 +0100
@@ -880,19 +880,15 @@ static void cio_reset_pgm_check_handler(
static int stsch_reset(struct subchannel_id schid, volatile struct schib *addr)
{
int rc;
- register struct subchannel_id reg1 asm ("1") = schid;

pgm_check_occured = 0;
s390_reset_pgm_handler = cio_reset_pgm_check_handler;
+ rc = stsch(schid, addr);
+ s390_reset_pgm_handler = NULL;

- asm volatile(
- " stsch 0(%2)\n"
- " ipm %0\n"
- " srl %0,28"
- : "=d" (rc)
- : "d" (reg1), "a" (addr), "m" (*addr) : "memory", "cc");
+ /* The program check handler could have changed pgm_check_occured */
+ barrier();

- s390_reset_pgm_handler = NULL;
if (pgm_check_occured)
return -EIO;
else