From 6ab6c31a5450b73133e04c3976469d6d72f55df3 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Tue, 24 Nov 2015 13:48:27 +0100 Subject: [PATCH] s390/facilities: optimize test_facility() test_facility() can be optimized for bits which must be set anyway, due to the check in head.S. This removes a couple of superfluous runtime checks. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/facility.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/s390/include/asm/facility.h b/arch/s390/include/asm/facility.h index 007163f91856..09b406db7529 100644 --- a/arch/s390/include/asm/facility.h +++ b/arch/s390/include/asm/facility.h @@ -34,6 +34,12 @@ static inline int __test_facility(unsigned long nr, void *facilities) */ static inline int test_facility(unsigned long nr) { + unsigned long facilities_als[] = { FACILITIES_ALS }; + + if (__builtin_constant_p(nr) && nr < sizeof(facilities_als) * 8) { + if (__test_facility(nr, &facilities_als)) + return 1; + } return __test_facility(nr, &S390_lowcore.stfle_fac_list); } -- 2.20.1