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Commit cf148998 authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

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: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarCornelia Huck <cohuck@redhat.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent e2dd8333

arch/s390/include/asm/facility.h

+18 −0
Original line number Diff line number Diff line
@@ -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;

arch/s390/include/asm/lowcore.h

+2 −1
Original line number Diff line number Diff line
@@ -151,7 +151,8 @@ 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 */

arch/s390/kernel/alternative.c

+2 −1
Original line number Diff line number Diff line
@@ -75,7 +75,8 @@ static void __init_or_module __apply_alternatives(struct alt_instr *start, 
		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)) {

arch/s390/kernel/early.c

+3 −0
Original line number Diff line number Diff line
@@ -193,6 +193,9 @@ static noinline __init void setup_facility_list(void) 
{

	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)

arch/s390/kernel/setup.c

+3 −1
Original line number Diff line number Diff line
@@ -340,7 +340,9 @@ 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));

	nmi_alloc_boot_cpu(lc);

	vdso_alloc_boot_cpu(lc);

	lc->sync_enter_timer = S390_lowcore.sync_enter_timer;