atomic64_32.h

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#ifndef _ASM_X86_ATOMIC64_32_H
#define _ASM_X86_ATOMIC64_32_H

#include <linux/compiler.h>
#include <linux/types.h>
#include <asm/processor.h>
//#include <asm/cmpxchg.h>

/* An 64bit atomic type */

typedef struct {
    u64 __aligned(8) counter;
} atomic64_t;

#define ATOMIC64_INIT(val)  { (val) }

#define __ATOMIC64_DECL(sym) void atomic64_##sym(atomic64_t *, ...)
#ifndef ATOMIC64_EXPORT
#define ATOMIC64_DECL_ONE __ATOMIC64_DECL
#else
#define ATOMIC64_DECL_ONE(sym) __ATOMIC64_DECL(sym); \
    ATOMIC64_EXPORT(atomic64_##sym)
#endif

#ifdef CONFIG_X86_CMPXCHG64
#define __alternative_atomic64(f, g, out, in...) \
    asm volatile("call %P[func]" \
             : out : [func] "i" (atomic64_##g##_cx8), ## in)

#define ATOMIC64_DECL(sym) ATOMIC64_DECL_ONE(sym##_cx8)
#else
#define __alternative_atomic64(f, g, out, in...) \
    alternative_call(atomic64_##f##_386, atomic64_##g##_cx8, \
             X86_FEATURE_CX8, ASM_OUTPUT2(out), ## in)

#define ATOMIC64_DECL(sym) ATOMIC64_DECL_ONE(sym##_cx8); \
    ATOMIC64_DECL_ONE(sym##_386)

ATOMIC64_DECL_ONE(add_386);
ATOMIC64_DECL_ONE(sub_386);
ATOMIC64_DECL_ONE(inc_386);
ATOMIC64_DECL_ONE(dec_386);
#endif

#define alternative_atomic64(f, out, in...) \
    __alternative_atomic64(f, f, ASM_OUTPUT2(out), ## in)

ATOMIC64_DECL(read);
ATOMIC64_DECL(set);
ATOMIC64_DECL(xchg);
ATOMIC64_DECL(add_return);
ATOMIC64_DECL(sub_return);
ATOMIC64_DECL(inc_return);
ATOMIC64_DECL(dec_return);
ATOMIC64_DECL(dec_if_positive);
ATOMIC64_DECL(inc_not_zero);
ATOMIC64_DECL(add_unless);

#undef ATOMIC64_DECL
#undef ATOMIC64_DECL_ONE
#undef __ATOMIC64_DECL
#undef ATOMIC64_EXPORT

static inline long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n)
{
    return cmpxchg64(&v->counter, o, n);
}

static inline long long atomic64_xchg(atomic64_t *v, long long n)
{
    long long o;
    unsigned high = (unsigned)(n >> 32);
    unsigned low = (unsigned)n;
    alternative_atomic64(xchg, "=&A" (o),
                 "S" (v), "b" (low), "c" (high)
                 : "memory");
    return o;
}

static inline void atomic64_set(atomic64_t *v, long long i)
{
    unsigned high = (unsigned)(i >> 32);
    unsigned low = (unsigned)i;
    alternative_atomic64(set, /* no output */,
                 "S" (v), "b" (low), "c" (high)
                 : "eax", "edx", "memory");
}

static inline long long atomic64_read(const atomic64_t *v)
{
    long long r;
    alternative_atomic64(read, "=&A" (r), "c" (v) : "memory");
    return r;
 }

static inline long long atomic64_add_return(long long i, atomic64_t *v)
{
    alternative_atomic64(add_return,
                 ASM_OUTPUT2("+A" (i), "+c" (v)),
                 ASM_NO_INPUT_CLOBBER("memory"));
    return i;
}

/*
 * Other variants with different arithmetic operators:
 */
static inline long long atomic64_sub_return(long long i, atomic64_t *v)
{
    alternative_atomic64(sub_return,
                 ASM_OUTPUT2("+A" (i), "+c" (v)),
                 ASM_NO_INPUT_CLOBBER("memory"));
    return i;
}

static inline long long atomic64_inc_return(atomic64_t *v)
{
    long long a;
    alternative_atomic64(inc_return, "=&A" (a),
                 "S" (v) : "memory", "ecx");
    return a;
}

static inline long long atomic64_dec_return(atomic64_t *v)
{
    long long a;
    alternative_atomic64(dec_return, "=&A" (a),
                 "S" (v) : "memory", "ecx");
    return a;
}

static inline long long atomic64_add(long long i, atomic64_t *v)
{
    __alternative_atomic64(add, add_return,
                   ASM_OUTPUT2("+A" (i), "+c" (v)),
                   ASM_NO_INPUT_CLOBBER("memory"));
    return i;
}

static inline long long atomic64_sub(long long i, atomic64_t *v)
{
    __alternative_atomic64(sub, sub_return,
                   ASM_OUTPUT2("+A" (i), "+c" (v)),
                   ASM_NO_INPUT_CLOBBER("memory"));
    return i;
}

static inline int atomic64_sub_and_test(long long i, atomic64_t *v)
{
    return atomic64_sub_return(i, v) == 0;
}

static inline void atomic64_inc(atomic64_t *v)
{
    __alternative_atomic64(inc, inc_return, /* no output */,
                   "S" (v) : "memory", "eax", "ecx", "edx");
}

static inline void atomic64_dec(atomic64_t *v)
{
    __alternative_atomic64(dec, dec_return, /* no output */,
                   "S" (v) : "memory", "eax", "ecx", "edx");
}

static inline int atomic64_dec_and_test(atomic64_t *v)
{
    return atomic64_dec_return(v) == 0;
}

static inline int atomic64_inc_and_test(atomic64_t *v)
{
    return atomic64_inc_return(v) == 0;
}

static inline int atomic64_add_negative(long long i, atomic64_t *v)
{
    return atomic64_add_return(i, v) < 0;
}

static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u)
{
    unsigned low = (unsigned)u;
    unsigned high = (unsigned)(u >> 32);
    alternative_atomic64(add_unless,
                 ASM_OUTPUT2("+A" (a), "+c" (low), "+D" (high)),
                 "S" (v) : "memory");
    return (int)a;
}


static inline int atomic64_inc_not_zero(atomic64_t *v)
{
    int r;
    alternative_atomic64(inc_not_zero, "=&a" (r),
                 "S" (v) : "ecx", "edx", "memory");
    return r;
}

static inline long long atomic64_dec_if_positive(atomic64_t *v)
{
    long long r;
    alternative_atomic64(dec_if_positive, "=&A" (r),
                 "S" (v) : "ecx", "memory");
    return r;
}

#undef alternative_atomic64
#undef __alternative_atomic64

#endif /* _ASM_X86_ATOMIC64_32_H */