forked from KolibriOS/kolibrios
275 lines
7.9 KiB
C
275 lines
7.9 KiB
C
#ifndef _ASM_X86_CMPXCHG_32_H
|
|
#define _ASM_X86_CMPXCHG_32_H
|
|
|
|
#include <linux/bitops.h> /* for LOCK_PREFIX */
|
|
|
|
/*
|
|
* Note: if you use set64_bit(), __cmpxchg64(), or their variants, you
|
|
* you need to test for the feature in boot_cpu_data.
|
|
*/
|
|
|
|
extern void __xchg_wrong_size(void);
|
|
|
|
/*
|
|
* Note: no "lock" prefix even on SMP: xchg always implies lock anyway
|
|
* Note 2: xchg has side effect, so that attribute volatile is necessary,
|
|
* but generally the primitive is invalid, *ptr is output argument. --ANK
|
|
*/
|
|
|
|
struct __xchg_dummy {
|
|
unsigned long a[100];
|
|
};
|
|
#define __xg(x) ((struct __xchg_dummy *)(x))
|
|
|
|
#define __xchg(x, ptr, size) \
|
|
({ \
|
|
__typeof(*(ptr)) __x = (x); \
|
|
switch (size) { \
|
|
case 1: \
|
|
asm volatile("xchgb %b0,%1" \
|
|
: "=q" (__x) \
|
|
: "m" (*__xg(ptr)), "0" (__x) \
|
|
: "memory"); \
|
|
break; \
|
|
case 2: \
|
|
asm volatile("xchgw %w0,%1" \
|
|
: "=r" (__x) \
|
|
: "m" (*__xg(ptr)), "0" (__x) \
|
|
: "memory"); \
|
|
break; \
|
|
case 4: \
|
|
asm volatile("xchgl %0,%1" \
|
|
: "=r" (__x) \
|
|
: "m" (*__xg(ptr)), "0" (__x) \
|
|
: "memory"); \
|
|
break; \
|
|
default: \
|
|
__xchg_wrong_size(); \
|
|
} \
|
|
__x; \
|
|
})
|
|
|
|
#define xchg(ptr, v) \
|
|
__xchg((v), (ptr), sizeof(*ptr))
|
|
|
|
/*
|
|
* The semantics of XCHGCMP8B are a bit strange, this is why
|
|
* there is a loop and the loading of %%eax and %%edx has to
|
|
* be inside. This inlines well in most cases, the cached
|
|
* cost is around ~38 cycles. (in the future we might want
|
|
* to do an SIMD/3DNOW!/MMX/FPU 64-bit store here, but that
|
|
* might have an implicit FPU-save as a cost, so it's not
|
|
* clear which path to go.)
|
|
*
|
|
* cmpxchg8b must be used with the lock prefix here to allow
|
|
* the instruction to be executed atomically, see page 3-102
|
|
* of the instruction set reference 24319102.pdf. We need
|
|
* the reader side to see the coherent 64bit value.
|
|
*/
|
|
static inline void __set_64bit(unsigned long long *ptr,
|
|
unsigned int low, unsigned int high)
|
|
{
|
|
asm volatile("\n1:\t"
|
|
"movl (%0), %%eax\n\t"
|
|
"movl 4(%0), %%edx\n\t"
|
|
LOCK_PREFIX "cmpxchg8b (%0)\n\t"
|
|
"jnz 1b"
|
|
: /* no outputs */
|
|
: "D"(ptr),
|
|
"b"(low),
|
|
"c"(high)
|
|
: "ax", "dx", "memory");
|
|
}
|
|
|
|
static inline void __set_64bit_constant(unsigned long long *ptr,
|
|
unsigned long long value)
|
|
{
|
|
__set_64bit(ptr, (unsigned int)value, (unsigned int)(value >> 32));
|
|
}
|
|
|
|
#define ll_low(x) *(((unsigned int *)&(x)) + 0)
|
|
#define ll_high(x) *(((unsigned int *)&(x)) + 1)
|
|
|
|
static inline void __set_64bit_var(unsigned long long *ptr,
|
|
unsigned long long value)
|
|
{
|
|
__set_64bit(ptr, ll_low(value), ll_high(value));
|
|
}
|
|
|
|
#define set_64bit(ptr, value) \
|
|
(__builtin_constant_p((value)) \
|
|
? __set_64bit_constant((ptr), (value)) \
|
|
: __set_64bit_var((ptr), (value)))
|
|
|
|
#define _set_64bit(ptr, value) \
|
|
(__builtin_constant_p(value) \
|
|
? __set_64bit(ptr, (unsigned int)(value), \
|
|
(unsigned int)((value) >> 32)) \
|
|
: __set_64bit(ptr, ll_low((value)), ll_high((value))))
|
|
|
|
extern void __cmpxchg_wrong_size(void);
|
|
|
|
/*
|
|
* 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 __raw_cmpxchg(ptr, old, new, size, lock) \
|
|
({ \
|
|
__typeof__(*(ptr)) __ret; \
|
|
__typeof__(*(ptr)) __old = (old); \
|
|
__typeof__(*(ptr)) __new = (new); \
|
|
switch (size) { \
|
|
case 1: \
|
|
asm volatile(lock "cmpxchgb %b1,%2" \
|
|
: "=a"(__ret) \
|
|
: "q"(__new), "m"(*__xg(ptr)), "0"(__old) \
|
|
: "memory"); \
|
|
break; \
|
|
case 2: \
|
|
asm volatile(lock "cmpxchgw %w1,%2" \
|
|
: "=a"(__ret) \
|
|
: "r"(__new), "m"(*__xg(ptr)), "0"(__old) \
|
|
: "memory"); \
|
|
break; \
|
|
case 4: \
|
|
asm volatile(lock "cmpxchgl %1,%2" \
|
|
: "=a"(__ret) \
|
|
: "r"(__new), "m"(*__xg(ptr)), "0"(__old) \
|
|
: "memory"); \
|
|
break; \
|
|
default: \
|
|
__cmpxchg_wrong_size(); \
|
|
} \
|
|
__ret; \
|
|
})
|
|
|
|
#define __cmpxchg(ptr, old, new, size) \
|
|
__raw_cmpxchg((ptr), (old), (new), (size), LOCK_PREFIX)
|
|
|
|
#define __sync_cmpxchg(ptr, old, new, size) \
|
|
__raw_cmpxchg((ptr), (old), (new), (size), "lock; ")
|
|
|
|
#define __cmpxchg_local(ptr, old, new, size) \
|
|
__raw_cmpxchg((ptr), (old), (new), (size), "")
|
|
|
|
#ifdef CONFIG_X86_CMPXCHG
|
|
#define __HAVE_ARCH_CMPXCHG 1
|
|
|
|
#define cmpxchg(ptr, old, new) \
|
|
__cmpxchg((ptr), (old), (new), sizeof(*ptr))
|
|
|
|
#define sync_cmpxchg(ptr, old, new) \
|
|
__sync_cmpxchg((ptr), (old), (new), sizeof(*ptr))
|
|
|
|
#define cmpxchg_local(ptr, old, new) \
|
|
__cmpxchg_local((ptr), (old), (new), sizeof(*ptr))
|
|
#endif
|
|
|
|
#ifdef CONFIG_X86_CMPXCHG64
|
|
#define cmpxchg64(ptr, o, n) \
|
|
((__typeof__(*(ptr)))__cmpxchg64((ptr), (unsigned long long)(o), \
|
|
(unsigned long long)(n)))
|
|
#define cmpxchg64_local(ptr, o, n) \
|
|
((__typeof__(*(ptr)))__cmpxchg64_local((ptr), (unsigned long long)(o), \
|
|
(unsigned long long)(n)))
|
|
#endif
|
|
|
|
static inline unsigned long long __cmpxchg64(volatile void *ptr,
|
|
unsigned long long old,
|
|
unsigned long long new)
|
|
{
|
|
unsigned long long prev;
|
|
asm volatile(LOCK_PREFIX "cmpxchg8b %3"
|
|
: "=A"(prev)
|
|
: "b"((unsigned long)new),
|
|
"c"((unsigned long)(new >> 32)),
|
|
"m"(*__xg(ptr)),
|
|
"0"(old)
|
|
: "memory");
|
|
return prev;
|
|
}
|
|
|
|
static inline unsigned long long __cmpxchg64_local(volatile void *ptr,
|
|
unsigned long long old,
|
|
unsigned long long new)
|
|
{
|
|
unsigned long long prev;
|
|
asm volatile("cmpxchg8b %3"
|
|
: "=A"(prev)
|
|
: "b"((unsigned long)new),
|
|
"c"((unsigned long)(new >> 32)),
|
|
"m"(*__xg(ptr)),
|
|
"0"(old)
|
|
: "memory");
|
|
return prev;
|
|
}
|
|
|
|
#ifndef CONFIG_X86_CMPXCHG
|
|
/*
|
|
* Building a kernel capable running on 80386. It may be necessary to
|
|
* simulate the cmpxchg on the 80386 CPU. For that purpose we define
|
|
* a function for each of the sizes we support.
|
|
*/
|
|
|
|
#define cmpxchg(ptr, o, n) \
|
|
({ \
|
|
__typeof__(*(ptr)) __ret; \
|
|
__ret = (__typeof__(*(ptr)))__cmpxchg((ptr), \
|
|
(unsigned long)(o), (unsigned long)(n), \
|
|
sizeof(*(ptr))); \
|
|
__ret; \
|
|
})
|
|
#define cmpxchg_local(ptr, o, n) \
|
|
({ \
|
|
__typeof__(*(ptr)) __ret; \
|
|
__ret = (__typeof__(*(ptr)))__cmpxchg_local((ptr), \
|
|
(unsigned long)(o), (unsigned long)(n), \
|
|
sizeof(*(ptr))); \
|
|
__ret; \
|
|
})
|
|
#endif
|
|
|
|
#ifndef CONFIG_X86_CMPXCHG64
|
|
/*
|
|
* Building a kernel capable running on 80386 and 80486. It may be necessary
|
|
* to simulate the cmpxchg8b on the 80386 and 80486 CPU.
|
|
*/
|
|
|
|
extern unsigned long long cmpxchg_486_u64(volatile void *, u64, u64);
|
|
|
|
#define cmpxchg64(ptr, o, n) \
|
|
({ \
|
|
__typeof__(*(ptr)) __ret; \
|
|
__typeof__(*(ptr)) __old = (o); \
|
|
__typeof__(*(ptr)) __new = (n); \
|
|
alternative_io("call cmpxchg8b_emu", \
|
|
"lock; cmpxchg8b (%%esi)" , \
|
|
X86_FEATURE_CX8, \
|
|
"=A" (__ret), \
|
|
"S" ((ptr)), "0" (__old), \
|
|
"b" ((unsigned int)__new), \
|
|
"c" ((unsigned int)(__new>>32)) \
|
|
: "memory"); \
|
|
__ret; })
|
|
|
|
|
|
|
|
#define cmpxchg64_local(ptr, o, n) \
|
|
({ \
|
|
__typeof__(*(ptr)) __ret; \
|
|
if (likely(boot_cpu_data.x86 > 4)) \
|
|
__ret = (__typeof__(*(ptr)))__cmpxchg64_local((ptr), \
|
|
(unsigned long long)(o), \
|
|
(unsigned long long)(n)); \
|
|
else \
|
|
__ret = (__typeof__(*(ptr)))cmpxchg_486_u64((ptr), \
|
|
(unsigned long long)(o), \
|
|
(unsigned long long)(n)); \
|
|
__ret; \
|
|
})
|
|
|
|
#endif
|
|
|
|
#endif /* _ASM_X86_CMPXCHG_32_H */
|