linux/arch/riscv/include/asm/cmpxchg.h

135 lines
3.3 KiB
C

/*
* Copyright (C) 2014 Regents of the University of California
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* 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.
*/
#ifndef _ASM_RISCV_CMPXCHG_H
#define _ASM_RISCV_CMPXCHG_H
#include <linux/bug.h>
#include <asm/barrier.h>
#define __xchg(new, ptr, size, asm_or) \
({ \
__typeof__(ptr) __ptr = (ptr); \
__typeof__(new) __new = (new); \
__typeof__(*(ptr)) __ret; \
switch (size) { \
case 4: \
__asm__ __volatile__ ( \
"amoswap.w" #asm_or " %0, %2, %1" \
: "=r" (__ret), "+A" (*__ptr) \
: "r" (__new) \
: "memory"); \
break; \
case 8: \
__asm__ __volatile__ ( \
"amoswap.d" #asm_or " %0, %2, %1" \
: "=r" (__ret), "+A" (*__ptr) \
: "r" (__new) \
: "memory"); \
break; \
default: \
BUILD_BUG(); \
} \
__ret; \
})
#define xchg(ptr, x) (__xchg((x), (ptr), sizeof(*(ptr)), .aqrl))
#define xchg32(ptr, x) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 4); \
xchg((ptr), (x)); \
})
#define xchg64(ptr, x) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
xchg((ptr), (x)); \
})
/*
* Atomic compare and exchange. Compare OLD with MEM, if identical,
* store NEW in MEM. Return the initial value in MEM. Success is
* indicated by comparing RETURN with OLD.
*/
#define __cmpxchg(ptr, old, new, size, lrb, scb) \
({ \
__typeof__(ptr) __ptr = (ptr); \
__typeof__(*(ptr)) __old = (old); \
__typeof__(*(ptr)) __new = (new); \
__typeof__(*(ptr)) __ret; \
register unsigned int __rc; \
switch (size) { \
case 4: \
__asm__ __volatile__ ( \
"0:" \
"lr.w" #scb " %0, %2\n" \
"bne %0, %z3, 1f\n" \
"sc.w" #lrb " %1, %z4, %2\n" \
"bnez %1, 0b\n" \
"1:" \
: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
: "rJ" (__old), "rJ" (__new) \
: "memory"); \
break; \
case 8: \
__asm__ __volatile__ ( \
"0:" \
"lr.d" #scb " %0, %2\n" \
"bne %0, %z3, 1f\n" \
"sc.d" #lrb " %1, %z4, %2\n" \
"bnez %1, 0b\n" \
"1:" \
: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
: "rJ" (__old), "rJ" (__new) \
: "memory"); \
break; \
default: \
BUILD_BUG(); \
} \
__ret; \
})
#define cmpxchg(ptr, o, n) \
(__cmpxchg((ptr), (o), (n), sizeof(*(ptr)), .aqrl, .aqrl))
#define cmpxchg_local(ptr, o, n) \
(__cmpxchg((ptr), (o), (n), sizeof(*(ptr)), , ))
#define cmpxchg32(ptr, o, n) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 4); \
cmpxchg((ptr), (o), (n)); \
})
#define cmpxchg32_local(ptr, o, n) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 4); \
cmpxchg_local((ptr), (o), (n)); \
})
#define cmpxchg64(ptr, o, n) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
cmpxchg((ptr), (o), (n)); \
})
#define cmpxchg64_local(ptr, o, n) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
cmpxchg_local((ptr), (o), (n)); \
})
#endif /* _ASM_RISCV_CMPXCHG_H */