diff options
Diffstat (limited to 'arch/riscv/include/asm/cmpxchg.h')
| -rw-r--r-- | arch/riscv/include/asm/cmpxchg.h | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/cmpxchg.h b/arch/riscv/include/asm/cmpxchg.h new file mode 100644 index 000000000000..db249dbc7b97 --- /dev/null +++ b/arch/riscv/include/asm/cmpxchg.h @@ -0,0 +1,134 @@ +/* + * 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 */ |