musl/arch/arm/atomic.h

148 lines
2.6 KiB
C

#ifndef _INTERNAL_ATOMIC_H
#define _INTERNAL_ATOMIC_H
#include <stdint.h>
static inline int a_ctz_l(unsigned long x)
{
static const char debruijn32[32] = {
0, 1, 23, 2, 29, 24, 19, 3, 30, 27, 25, 11, 20, 8, 4, 13,
31, 22, 28, 18, 26, 10, 7, 12, 21, 17, 9, 6, 16, 5, 15, 14
};
return debruijn32[(x&-x)*0x076be629 >> 27];
}
static inline int a_ctz_64(uint64_t x)
{
uint32_t y = x;
if (!y) {
y = x>>32;
return 32 + a_ctz_l(y);
}
return a_ctz_l(y);
}
#if ((__ARM_ARCH_6__ || __ARM_ARCH_6K__ || __ARM_ARCH_6ZK__) && !__thumb__) \
|| __ARM_ARCH_7A__ || __ARM_ARCH_7R__ || __ARM_ARCH >= 7
#if __ARM_ARCH_7A__ || __ARM_ARCH_7R__ || __ARM_ARCH >= 7
#define MEM_BARRIER "dmb ish"
#else
#define MEM_BARRIER "mcr p15,0,r0,c7,c10,5"
#endif
static inline int __k_cas(int t, int s, volatile int *p)
{
int ret;
__asm__(
" " MEM_BARRIER "\n"
"1: ldrex %0,%3\n"
" subs %0,%0,%1\n"
#ifdef __thumb__
" itt eq\n"
#endif
" strexeq %0,%2,%3\n"
" teqeq %0,#1\n"
" beq 1b\n"
" " MEM_BARRIER "\n"
: "=&r"(ret)
: "r"(t), "r"(s), "Q"(*p)
: "memory", "cc" );
return ret;
}
#else
#define __k_cas ((int (*)(int, int, volatile int *))0xffff0fc0)
#endif
static inline int a_cas(volatile int *p, int t, int s)
{
int old;
for (;;) {
if (!__k_cas(t, s, p))
return t;
if ((old=*p) != t)
return old;
}
}
static inline void *a_cas_p(volatile void *p, void *t, void *s)
{
return (void *)a_cas(p, (int)t, (int)s);
}
static inline int a_swap(volatile int *x, int v)
{
int old;
do old = *x;
while (__k_cas(old, v, x));
return old;
}
static inline int a_fetch_add(volatile int *x, int v)
{
int old;
do old = *x;
while (__k_cas(old, old+v, x));
return old;
}
static inline void a_inc(volatile int *x)
{
a_fetch_add(x, 1);
}
static inline void a_dec(volatile int *x)
{
a_fetch_add(x, -1);
}
static inline void a_store(volatile int *p, int x)
{
while (__k_cas(*p, x, p));
}
static inline void a_spin()
{
__k_cas(0, 0, &(int){0});
}
static inline void a_crash()
{
*(volatile char *)0=0;
}
static inline void a_and(volatile int *p, int v)
{
int old;
do old = *p;
while (__k_cas(old, old&v, p));
}
static inline void a_or(volatile int *p, int v)
{
int old;
do old = *p;
while (__k_cas(old, old|v, p));
}
static inline void a_or_l(volatile void *p, long v)
{
a_or(p, v);
}
static inline void a_and_64(volatile uint64_t *p, uint64_t v)
{
union { uint64_t v; uint32_t r[2]; } u = { v };
a_and((int *)p, u.r[0]);
a_and((int *)p+1, u.r[1]);
}
static inline void a_or_64(volatile uint64_t *p, uint64_t v)
{
union { uint64_t v; uint32_t r[2]; } u = { v };
a_or((int *)p, u.r[0]);
a_or((int *)p+1, u.r[1]);
}
#endif