/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
#ifndef __ASM_CMPXCHG_H
#define __ASM_CMPXCHG_H
#include <asm/barrier.h>
#include <linux/build_bug.h>
#define __xchg_asm(amswap_db, m, val) \
({ \
__typeof(val) __ret; \
\
__asm__ __volatile__ ( \
" "amswap_db" %1, %z2, %0 \n" \
: "+ZB" (*m), "=&r" (__ret) \
: "Jr" (val) \
: "memory"); \
\
__ret; \
})
static inline unsigned long __xchg(volatile void *ptr, unsigned long x,
int size)
{
switch (size) {
case 4:
return __xchg_asm("amswap_db.w", (volatile u32 *)ptr, (u32)x);
case 8:
return __xchg_asm("amswap_db.d", (volatile u64 *)ptr, (u64)x);
default:
BUILD_BUG();
}
return 0;
}
#define arch_xchg(ptr, x) \
({ \
__typeof__(*(ptr)) __res; \
\
__res = (__typeof__(*(ptr))) \
__xchg((ptr), (unsigned long)(x), sizeof(*(ptr))); \
\
__res; \
})
#define __cmpxchg_asm(ld, st, m, old, new) \
({ \
__typeof(old) __ret; \
\
__asm__ __volatile__( \
"1: " ld " %0, %2 # __cmpxchg_asm \n" \
" bne %0, %z3, 2f \n" \
" or $t0, %z4, $zero \n" \
" " st " $t0, %1 \n" \
" beq $zero, $t0, 1b \n" \
"2: \n" \
__WEAK_LLSC_MB \
: "=&r" (__ret), "=ZB"(*m) \
: "ZB"(*m), "Jr" (old), "Jr" (new) \
: "t0", "memory"); \
\
__ret; \
})
static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
unsigned long new, unsigned int size)
{
switch (size) {
case 4:
return __cmpxchg_asm("ll.w", "sc.w", (volatile u32 *)ptr,
(u32)old, new);
case 8:
return __cmpxchg_asm("ll.d", "sc.d", (volatile u64 *)ptr,
(u64)old, new);
default:
BUILD_BUG();
}
return 0;
}
#define arch_cmpxchg_local(ptr, old, new) \
((__typeof__(*(ptr))) \
__cmpxchg((ptr), \
(unsigned long)(__typeof__(*(ptr)))(old), \
(unsigned long)(__typeof__(*(ptr)))(new), \
sizeof(*(ptr))))
#define arch_cmpxchg(ptr, old, new) \
({ \
__typeof__(*(ptr)) __res; \
\
__res = arch_cmpxchg_local((ptr), (old), (new)); \
\
__res; \
})
#ifdef CONFIG_64BIT
#define arch_cmpxchg64_local(ptr, o, n) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
arch_cmpxchg_local((ptr), (o), (n)); \
})
#define arch_cmpxchg64(ptr, o, n) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
arch_cmpxchg((ptr), (o), (n)); \
})
#else
#include <asm-generic/cmpxchg-local.h>
#define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n))
#define arch_cmpxchg64(ptr, o, n) arch_cmpxchg64_local((ptr), (o), (n))
#endif
#endif /* __ASM_CMPXCHG_H */
