From cf1489984641369611556bf00c48f945c77bcf02 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 16 Jan 2018 07:03:44 +0100 Subject: s390/alternative: use a copy of the facility bit mask To be able to switch off specific CPU alternatives with kernel parameters make a copy of the facility bit mask provided by STFLE and use the copy for the decision to apply an alternative. Reviewed-by: David Hildenbrand Reviewed-by: Cornelia Huck Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/facility.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'arch/s390/include/asm/facility.h') diff --git a/arch/s390/include/asm/facility.h b/arch/s390/include/asm/facility.h index fbe0c4be3cd8..99c8ce30b3cd 100644 --- a/arch/s390/include/asm/facility.h +++ b/arch/s390/include/asm/facility.h @@ -15,6 +15,24 @@ #define MAX_FACILITY_BIT (sizeof(((struct lowcore *)0)->stfle_fac_list) * 8) +static inline void __set_facility(unsigned long nr, void *facilities) +{ + unsigned char *ptr = (unsigned char *) facilities; + + if (nr >= MAX_FACILITY_BIT) + return; + ptr[nr >> 3] |= 0x80 >> (nr & 7); +} + +static inline void __clear_facility(unsigned long nr, void *facilities) +{ + unsigned char *ptr = (unsigned char *) facilities; + + if (nr >= MAX_FACILITY_BIT) + return; + ptr[nr >> 3] &= ~(0x80 >> (nr & 7)); +} + static inline int __test_facility(unsigned long nr, void *facilities) { unsigned char *ptr; -- cgit v1.2.3