[kvm-unit-tests PATCH v2 2/5] lib: s390x: uv: Dirty CC before uvc execution

Janosch Frank
2024-01-31T07:44:58Z

Dirtying the CC allows us to find missing CC changes.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
lib/s390x/asm/uv.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/s390x/asm/uv.h b/lib/s390x/asm/uv.h
index e9fb19af..611dcd3f 100644
--- a/lib/s390x/asm/uv.h
+++ b/lib/s390x/asm/uv.h
@@ -216,14 +216,16 @@ struct uv_cb_ssc {

static inline int uv_call_once(unsigned long r1, unsigned long r2)
{
+ uint64_t bogus_cc = 1;
int cc;

asm volatile(
+ " tmll %[bogus_cc],3\n"
"0: .insn rrf,0xB9A40000,%[r1],%[r2],0,0\n"
" ipm %[cc]\n"
" srl %[cc],28\n"
: [cc] "=d" (cc)
- : [r1] "a" (r1), [r2] "a" (r2)
+ : [r1] "a" (r1), [r2] "a" (r2), [bogus_cc] "d" (bogus_cc)
: "memory", "cc");

if (UVC_ERR_DEBUG && cc == 1)
--
2.40.1