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#ifndef __CR_ATOMIC_H__
#define __CR_ATOMIC_H__
#include "common/arch/arm/asm/processor.h"
typedef struct {
int counter;
} atomic_t;
/* Copied from the Linux kernel header arch/arm/include/asm/atomic.h */
#if defined(CONFIG_ARMV7)
#define smp_mb() __asm__ __volatile__("dmb" : : : "memory")
static inline int atomic_cmpxchg(atomic_t *ptr, int old, int new)
{
int oldval;
unsigned long res;
smp_mb();
prefetchw(&ptr->counter);
do {
__asm__ __volatile__("@ atomic_cmpxchg\n"
"ldrex %1, [%3]\n"
"mov %0, #0\n"
"teq %1, %4\n"
"it eq\n"
"strexeq %0, %5, [%3]\n"
: "=&r"(res), "=&r"(oldval), "+Qo"(ptr->counter)
: "r"(&ptr->counter), "Ir"(old), "r"(new)
: "cc");
} while (res);
smp_mb();
return oldval;
}
#elif defined(CONFIG_ARMV6)
/* SMP isn't supported for ARMv6 */
#define smp_mb() __asm__ __volatile__("mcr p15, 0, %0, c7, c10, 5" : : "r"(0) : "memory")
static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
{
int ret;
ret = v->counter;
if (ret == old)
v->counter = new;
return ret;
}
#else
#error ARM architecture version (CONFIG_ARMV*) not set or unsupported.
#endif
static inline int atomic_read(const atomic_t *v)
{
return (*(volatile int *)&(v)->counter);
}
static inline void atomic_set(atomic_t *v, int i)
{
v->counter = i;
}
#define atomic_get atomic_read
static inline int atomic_add_return(int i, atomic_t *v)
{
unsigned long tmp;
int result;
smp_mb();
__asm__ __volatile__("@ atomic_add_return\n"
"1: ldrex %0, [%3]\n"
" add %0, %0, %4\n"
" strex %1, %0, [%3]\n"
" teq %1, #0\n"
" bne 1b\n"
: "=&r"(result), "=&r"(tmp), "+Qo"(v->counter)
: "r"(&v->counter), "Ir"(i)
: "cc");
smp_mb();
return result;
}
static inline int atomic_sub_return(int i, atomic_t *v)
{
unsigned long tmp;
int result;
smp_mb();
__asm__ __volatile__("@ atomic_sub_return\n"
"1: ldrex %0, [%3]\n"
" sub %0, %0, %4\n"
" strex %1, %0, [%3]\n"
" teq %1, #0\n"
" bne 1b\n"
: "=&r"(result), "=&r"(tmp), "+Qo"(v->counter)
: "r"(&v->counter), "Ir"(i)
: "cc");
smp_mb();
return result;
}
static inline int atomic_inc(atomic_t *v)
{
return atomic_add_return(1, v) - 1;
}
static inline int atomic_add(int val, atomic_t *v)
{
return atomic_add_return(val, v) - val;
}
static inline int atomic_dec(atomic_t *v)
{
return atomic_sub_return(1, v) + 1;
}
/* true if the result is 0, or false for all other cases. */
#define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0)
#define atomic_dec_return(v) (atomic_sub_return(1, v))
#define atomic_inc_return(v) (atomic_add_return(1, v))
#endif /* __CR_ATOMIC_H__ */
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