linux_dsm_epyc7002/arch/s390/include/asm/facility.h
Vasily Gorbik cf3dbe5dac s390/kasan: support preemptible kernel build
When the kernel is built with:
CONFIG_PREEMPT=y
CONFIG_PREEMPT_COUNT=y
"stfle" function used by kasan initialization code makes additional
call to preempt_count_add/preempt_count_sub. To avoid removing kasan
instrumentation from sched code where those functions leave split stfle
function and provide __stfle variant without preemption handling to be
used by Kasan.

Reported-by: Benjamin Block <bblock@linux.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-10-22 08:37:45 +02:00

97 lines
2.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright IBM Corp. 1999, 2009
*
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
*/
#ifndef __ASM_FACILITY_H
#define __ASM_FACILITY_H
#include <asm/facility-defs.h>
#include <linux/string.h>
#include <linux/preempt.h>
#include <asm/lowcore.h>
#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;
if (nr >= MAX_FACILITY_BIT)
return 0;
ptr = (unsigned char *) facilities + (nr >> 3);
return (*ptr & (0x80 >> (nr & 7))) != 0;
}
/*
* The test_facility function uses the bit odering where the MSB is bit 0.
* That makes it easier to query facility bits with the bit number as
* documented in the Principles of Operation.
*/
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);
}
/**
* stfle - Store facility list extended
* @stfle_fac_list: array where facility list can be stored
* @size: size of passed in array in double words
*/
static inline void __stfle(u64 *stfle_fac_list, int size)
{
unsigned long nr;
asm volatile(
" stfl 0(0)\n"
: "=m" (S390_lowcore.stfl_fac_list));
nr = 4; /* bytes stored by stfl */
memcpy(stfle_fac_list, &S390_lowcore.stfl_fac_list, 4);
if (S390_lowcore.stfl_fac_list & 0x01000000) {
/* More facility bits available with stfle */
register unsigned long reg0 asm("0") = size - 1;
asm volatile(".insn s,0xb2b00000,0(%1)" /* stfle */
: "+d" (reg0)
: "a" (stfle_fac_list)
: "memory", "cc");
nr = (reg0 + 1) * 8; /* # bytes stored by stfle */
}
memset((char *) stfle_fac_list + nr, 0, size * 8 - nr);
}
static inline void stfle(u64 *stfle_fac_list, int size)
{
preempt_disable();
__stfle(stfle_fac_list, size);
preempt_enable();
}
#endif /* __ASM_FACILITY_H */