[Qemu-devel] [PATCH] s390-ccw: force diag 308 subcode to unsigned long

From: Cornelia Huck <cohuck@redhat.com>
To: Christian Borntraeger <borntraeger@de.ibm.com>,
	Thomas Huth <thuth@redhat.com>
Cc: qemu-s390x@nongnu.org, qemu-devel@nongnu.org,
	Cornelia Huck <cohuck@redhat.com>,
	qemu-stable@nongnu.org
Subject: [Qemu-devel] [PATCH] s390-ccw: force diag 308 subcode to unsigned long
Date: Wed,  2 May 2018 14:52:21 +0200	[thread overview]
Message-ID: <20180502125221.4877-1-cohuck@redhat.com> (raw)

We currently pass an integer as the subcode parameter. However,
the upper bits of the register containing the subcode need to
be 0, which is not guaranteed unless we explicitly specify the
subcode to be an unsigned long value.

Fixes: d046c51dad3 ("pc-bios/s390-ccw: Get device address via diag 308/6")
Cc: qemu-stable@nongnu.org
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
 pc-bios/s390-ccw/iplb.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pc-bios/s390-ccw/iplb.h b/pc-bios/s390-ccw/iplb.h
index 5357a36d51..ded20c834e 100644
--- a/pc-bios/s390-ccw/iplb.h
+++ b/pc-bios/s390-ccw/iplb.h
@@ -101,10 +101,11 @@ static inline bool manage_iplb(IplParameterBlock *iplb, bool store)
 {
     register unsigned long addr asm("0") = (unsigned long) iplb;
     register unsigned long rc asm("1") = 0;
+    unsigned long subcode = store ? 6 : 5;
 
     asm volatile ("diag %0,%2,0x308\n"
                   : "+d" (addr), "+d" (rc)
-                  : "d" (store ? 6 : 5)
+                  : "d" (subcode)
                   : "memory", "cc");
     return rc == 0x01;
 }
-- 
2.14.3
