[PATCH] s390: fix detection of vector enhancements facility 1 vs. vector packed decimal facility

David Hildenbrand
2021-05-03T12:13:01Z

The PoP documents:
134: The vector packed decimal facility is installed in the
z/Architecture architectural mode. When bit 134 is
one, bit 129 is also one.
135: The vector enhancements facility 1 is installed in
the z/Architecture architectural mode. When bit 135
is one, bit 129 is also one.

Looks like we confuse the vector enhancements facility 1 ("EXT") with the
Vector packed decimal facility ("BCD"). Let's fix the facility checks.

Detected while working on QEMU/tcg z14 support and only unlocking
the vector enhancements facility 1, but not the vector packed decimal
facility.

Fixes: 2583b848cad0 ("s390: report new vector facilities")
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexander Egorenkov <egorenar@linux.ibm.com>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/s390/kernel/setup.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 72134f9f6ff5..5aab59ad5688 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -937,9 +937,9 @@ static int __init setup_hwcaps(void)
if (MACHINE_HAS_VX) {
elf_hwcap |= HWCAP_S390_VXRS;
if (test_facility(134))
- elf_hwcap |= HWCAP_S390_VXRS_EXT;
- if (test_facility(135))
elf_hwcap |= HWCAP_S390_VXRS_BCD;
+ if (test_facility(135))
+ elf_hwcap |= HWCAP_S390_VXRS_EXT;
if (test_facility(148))
elf_hwcap |= HWCAP_S390_VXRS_EXT2;
if (test_facility(152))
--
2.30.2