4.14-stable review patch. If anyone has any objections, please let me know.
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From: Martin Schwidefsky schwidefsky@de.ibm.com
[ Upstream commit cf1489984641369611556bf00c48f945c77bcf02 ]
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 david@redhat.com Reviewed-by: Cornelia Huck cohuck@redhat.com Signed-off-by: Martin Schwidefsky schwidefsky@de.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/s390/include/asm/facility.h | 18 ++++++++++++++++++ arch/s390/include/asm/lowcore.h | 3 ++- arch/s390/kernel/alternative.c | 3 ++- arch/s390/kernel/early.c | 3 +++ arch/s390/kernel/setup.c | 4 +++- arch/s390/kernel/smp.c | 4 +++- 6 files changed, 31 insertions(+), 4 deletions(-)
--- 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; --- a/arch/s390/include/asm/lowcore.h +++ b/arch/s390/include/asm/lowcore.h @@ -155,7 +155,8 @@ struct lowcore { __u8 pad_0x0e20[0x0f00-0x0e20]; /* 0x0e20 */
/* Extended facility list */ - __u64 stfle_fac_list[32]; /* 0x0f00 */ + __u64 stfle_fac_list[16]; /* 0x0f00 */ + __u64 alt_stfle_fac_list[16]; /* 0x0f80 */ __u8 pad_0x1000[0x11b0-0x1000]; /* 0x1000 */
/* Pointer to the machine check extended save area */ --- a/arch/s390/kernel/alternative.c +++ b/arch/s390/kernel/alternative.c @@ -74,7 +74,8 @@ static void __init_or_module __apply_alt instr = (u8 *)&a->instr_offset + a->instr_offset; replacement = (u8 *)&a->repl_offset + a->repl_offset;
- if (!test_facility(a->facility)) + if (!__test_facility(a->facility, + S390_lowcore.alt_stfle_fac_list)) continue;
if (unlikely(a->instrlen % 2 || a->replacementlen % 2)) { --- a/arch/s390/kernel/early.c +++ b/arch/s390/kernel/early.c @@ -329,6 +329,9 @@ static noinline __init void setup_facili { stfle(S390_lowcore.stfle_fac_list, ARRAY_SIZE(S390_lowcore.stfle_fac_list)); + memcpy(S390_lowcore.alt_stfle_fac_list, + S390_lowcore.stfle_fac_list, + sizeof(S390_lowcore.alt_stfle_fac_list)); }
static __init void detect_diag9c(void) --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -339,7 +339,9 @@ static void __init setup_lowcore(void) lc->preempt_count = S390_lowcore.preempt_count; lc->stfl_fac_list = S390_lowcore.stfl_fac_list; memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list, - MAX_FACILITY_BIT/8); + sizeof(lc->stfle_fac_list)); + memcpy(lc->alt_stfle_fac_list, S390_lowcore.alt_stfle_fac_list, + sizeof(lc->alt_stfle_fac_list)); if (MACHINE_HAS_VX || MACHINE_HAS_GS) { unsigned long bits, size;
--- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -282,7 +282,9 @@ static void pcpu_prepare_secondary(struc __ctl_store(lc->cregs_save_area, 0, 15); save_access_regs((unsigned int *) lc->access_regs_save_area); memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list, - MAX_FACILITY_BIT/8); + sizeof(lc->stfle_fac_list)); + memcpy(lc->alt_stfle_fac_list, S390_lowcore.alt_stfle_fac_list, + sizeof(lc->alt_stfle_fac_list)); }
static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)