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

Janosch Frank
2021-05-03T14:11:44Z

On 5/3/21 2:12 PM, David Hildenbrand wrote:
> 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.

Reviewed-by: Janosch Frank <frankja@linux.ibm.com>

>
> 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))
>