4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Martin Schwidefsky <schwidef...@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 <da...@redhat.com>
Reviewed-by: Cornelia Huck <coh...@redhat.com>
Signed-off-by: Martin Schwidefsky <schwidef...@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gre...@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
@@ -17,6 +17,24 @@
#define MAX_FACILITY_BIT (256*8) /* stfle_fac_list has 256 bytes */
+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
@@ -150,7 +150,8 @@ 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 vector register 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
@@ -299,6 +299,9 @@ 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
@@ -336,7 +336,9 @@ static void __init setup_lowcore(void)
lc->machine_flags = S390_lowcore.machine_flags;
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)
lc->vector_save_area_addr =
(unsigned long) &lc->vector_save_area;
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -253,7 +253,9 @@ 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)
