[S390] cio: fix stsch_reset.

Copy inline assembly of stsch and add "memory" to clobber list in order
to prevent gcc from optimizing away the checking of the global variable
"pgm_check_occured".

Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 10 insertions, 3 deletions

diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index 3a403f195cf8..b471ac4a1bf6 100644
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -2,8 +2,7 @@
  *  drivers/s390/cio/cio.c
  *   S/390 common I/O routines -- low level i/o calls
  *
- *    Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,
- *                            IBM Corporation
+ *    Copyright (C) IBM Corp. 1999,2006
  *    Author(s): Ingo Adlung (adlung@de.ibm.com)
  *               Cornelia Huck (cornelia.huck@de.ibm.com)
  *               Arnd Bergmann (arndb@de.ibm.com)
@@ -881,10 +880,18 @@ static void cio_reset_pgm_check_handler(void)
 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);
+
+        asm volatile(
+                "       stsch   0(%2)\n"
+                "       ipm     %0\n"
+                "       srl     %0,28"
+                : "=d" (rc)
+                : "d" (reg1), "a" (addr), "m" (*addr) : "memory", "cc");
+
         s390_reset_pgm_handler = NULL;
         if (pgm_check_occured)
                 return -EIO;