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/*
* Based on arch/arm/include/asm/cmpxchg.h
*
* Copyright (C) 2012 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ASM_CMPXCHG_H
#define __ASM_CMPXCHG_H
#include <linux/bug.h>
#include <linux/mmdebug.h>
#include <asm/atomic.h>
#include <asm/barrier.h>
#include <asm/lse.h>
static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size)
{
unsigned long ret, tmp;
switch (size) {
case 1:
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
" prfm pstl1strm, %2\n"
"1: ldxrb %w0, %2\n"
" stlxrb %w1, %w3, %2\n"
" cbnz %w1, 1b\n"
" dmb ish",
/* LSE atomics */
" nop\n"
" nop\n"
" swpalb %w3, %w0, %2\n"
" nop\n"
" nop")
: "=&r" (ret), "=&r" (tmp), "+Q" (*(u8 *)ptr)
: "r" (x)
: "memory");
break;
case 2:
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
" prfm pstl1strm, %2\n"
"1: ldxrh %w0, %2\n"
" stlxrh %w1, %w3, %2\n"
" cbnz %w1, 1b\n"
" dmb ish",
/* LSE atomics */
" nop\n"
" nop\n"
" swpalh %w3, %w0, %2\n"
" nop\n"
" nop")
: "=&r" (ret), "=&r" (tmp), "+Q" (*(u16 *)ptr)
: "r" (x)
: "memory");
break;
case 4:
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
" prfm pstl1strm, %2\n"
"1: ldxr %w0, %2\n"
" stlxr %w1, %w3, %2\n"
" cbnz %w1, 1b\n"
" dmb ish",
/* LSE atomics */
" nop\n"
" nop\n"
" swpal %w3, %w0, %2\n"
" nop\n"
" nop")
: "=&r" (ret), "=&r" (tmp), "+Q" (*(u32 *)ptr)
: "r" (x)
: "memory");
break;
case 8:
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
" prfm pstl1strm, %2\n"
"1: ldxr %0, %2\n"
" stlxr %w1, %3, %2\n"
" cbnz %w1, 1b\n"
" dmb ish",
/* LSE atomics */
" nop\n"
" nop\n"
" swpal %3, %0, %2\n"
" nop\n"
" nop")
: "=&r" (ret), "=&r" (tmp), "+Q" (*(u64 *)ptr)
: "r" (x)
: "memory");
break;
default:
BUILD_BUG();
}
return ret;
}
#define xchg(ptr,x) \
({ \
__typeof__(*(ptr)) __ret; \
__ret = (__typeof__(*(ptr))) \
__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))); \
__ret; \
})
static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
unsigned long new, int size)
{
switch (size) {
case 1:
return __cmpxchg_case_1(ptr, (u8)old, new);
case 2:
return __cmpxchg_case_2(ptr, (u16)old, new);
case 4:
return __cmpxchg_case_4(ptr, old, new);
case 8:
return __cmpxchg_case_8(ptr, old, new);
default:
BUILD_BUG();
}
unreachable();
}
static inline unsigned long __cmpxchg_mb(volatile void *ptr, unsigned long old,
unsigned long new, int size)
{
switch (size) {
case 1:
return __cmpxchg_case_mb_1(ptr, (u8)old, new);
case 2:
return __cmpxchg_case_mb_2(ptr, (u16)old, new);
case 4:
return __cmpxchg_case_mb_4(ptr, old, new);
case 8:
return __cmpxchg_case_mb_8(ptr, old, new);
default:
BUILD_BUG();
}
unreachable();
}
#define cmpxchg(ptr, o, n) \
({ \
__typeof__(*(ptr)) __ret; \
__ret = (__typeof__(*(ptr))) \
__cmpxchg_mb((ptr), (unsigned long)(o), (unsigned long)(n), \
sizeof(*(ptr))); \
__ret; \
})
#define cmpxchg_local(ptr, o, n) \
({ \
__typeof__(*(ptr)) __ret; \
__ret = (__typeof__(*(ptr))) \
__cmpxchg((ptr), (unsigned long)(o), \
(unsigned long)(n), sizeof(*(ptr))); \
__ret; \
})
#define system_has_cmpxchg_double() 1
#define __cmpxchg_double_check(ptr1, ptr2) \
({ \
if (sizeof(*(ptr1)) != 8) \
BUILD_BUG(); \
VM_BUG_ON((unsigned long *)(ptr2) - (unsigned long *)(ptr1) != 1); \
})
#define cmpxchg_double(ptr1, ptr2, o1, o2, n1, n2) \
({\
int __ret;\
__cmpxchg_double_check(ptr1, ptr2); \
__ret = !__cmpxchg_double_mb((unsigned long)(o1), (unsigned long)(o2), \
(unsigned long)(n1), (unsigned long)(n2), \
ptr1); \
__ret; \
})
#define cmpxchg_double_local(ptr1, ptr2, o1, o2, n1, n2) \
({\
int __ret;\
__cmpxchg_double_check(ptr1, ptr2); \
__ret = !__cmpxchg_double((unsigned long)(o1), (unsigned long)(o2), \
(unsigned long)(n1), (unsigned long)(n2), \
ptr1); \
__ret; \
})
#define _protect_cmpxchg_local(pcp, o, n) \
({ \
typeof(*raw_cpu_ptr(&(pcp))) __ret; \
preempt_disable(); \
__ret = cmpxchg_local(raw_cpu_ptr(&(pcp)), o, n); \
preempt_enable(); \
__ret; \
})
#define this_cpu_cmpxchg_1(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
#define this_cpu_cmpxchg_2(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
#define this_cpu_cmpxchg_4(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
#define this_cpu_cmpxchg_8(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
#define this_cpu_cmpxchg_double_8(ptr1, ptr2, o1, o2, n1, n2) \
({ \
int __ret; \
preempt_disable(); \
__ret = cmpxchg_double_local( raw_cpu_ptr(&(ptr1)), \
raw_cpu_ptr(&(ptr2)), \
o1, o2, n1, n2); \
preempt_enable(); \
__ret; \
})
#define cmpxchg64(ptr,o,n) cmpxchg((ptr),(o),(n))
#define cmpxchg64_local(ptr,o,n) cmpxchg_local((ptr),(o),(n))
#define cmpxchg64_relaxed(ptr,o,n) cmpxchg_local((ptr),(o),(n))
#endif /* __ASM_CMPXCHG_H */
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