system.h

linux 内核源代码

}

/* This function doesn't exist, so you'll get a linker error
   if something tries to do an invalid xchg().  */
extern void __xchg_called_with_bad_pointer(void);

#define __xchg(ptr, x, size) \
({ \
	unsigned long __xchg__res; \
	volatile void *__xchg__ptr = (ptr); \
	switch (size) { \
		case 1: __xchg__res = __xchg_u8(__xchg__ptr, x); break; \
		case 2: __xchg__res = __xchg_u16(__xchg__ptr, x); break; \
		case 4: __xchg__res = __xchg_u32(__xchg__ptr, x); break; \
		case 8: __xchg__res = __xchg_u64(__xchg__ptr, x); break; \
		default: __xchg_called_with_bad_pointer(); __xchg__res = x; \
	} \
	__xchg__res; \
})

#define xchg(ptr,x)							     \
  ({									     \
     __typeof__(*(ptr)) _x_ = (x);					     \
     (__typeof__(*(ptr))) __xchg((ptr), (unsigned long)_x_, sizeof(*(ptr))); \
  })

static inline unsigned long
__xchg_u8_local(volatile char *m, unsigned long val)
{
	unsigned long ret, tmp, addr64;

	__asm__ __volatile__(
	"	andnot	%4,7,%3\n"
	"	insbl	%1,%4,%1\n"
	"1:	ldq_l	%2,0(%3)\n"
	"	extbl	%2,%4,%0\n"
	"	mskbl	%2,%4,%2\n"
	"	or	%1,%2,%2\n"
	"	stq_c	%2,0(%3)\n"
	"	beq	%2,2f\n"
	".subsection 2\n"
	"2:	br	1b\n"
	".previous"
	: "=&r" (ret), "=&r" (val), "=&r" (tmp), "=&r" (addr64)
	: "r" ((long)m), "1" (val) : "memory");

	return ret;
}

static inline unsigned long
__xchg_u16_local(volatile short *m, unsigned long val)
{
	unsigned long ret, tmp, addr64;

	__asm__ __volatile__(
	"	andnot	%4,7,%3\n"
	"	inswl	%1,%4,%1\n"
	"1:	ldq_l	%2,0(%3)\n"
	"	extwl	%2,%4,%0\n"
	"	mskwl	%2,%4,%2\n"
	"	or	%1,%2,%2\n"
	"	stq_c	%2,0(%3)\n"
	"	beq	%2,2f\n"
	".subsection 2\n"
	"2:	br	1b\n"
	".previous"
	: "=&r" (ret), "=&r" (val), "=&r" (tmp), "=&r" (addr64)
	: "r" ((long)m), "1" (val) : "memory");

	return ret;
}

static inline unsigned long
__xchg_u32_local(volatile int *m, unsigned long val)
{
	unsigned long dummy;

	__asm__ __volatile__(
	"1:	ldl_l %0,%4\n"
	"	bis $31,%3,%1\n"
	"	stl_c %1,%2\n"
	"	beq %1,2f\n"
	".subsection 2\n"
	"2:	br 1b\n"
	".previous"
	: "=&r" (val), "=&r" (dummy), "=m" (*m)
	: "rI" (val), "m" (*m) : "memory");

	return val;
}

static inline unsigned long
__xchg_u64_local(volatile long *m, unsigned long val)
{
	unsigned long dummy;

	__asm__ __volatile__(
	"1:	ldq_l %0,%4\n"
	"	bis $31,%3,%1\n"
	"	stq_c %1,%2\n"
	"	beq %1,2f\n"
	".subsection 2\n"
	"2:	br 1b\n"
	".previous"
	: "=&r" (val), "=&r" (dummy), "=m" (*m)
	: "rI" (val), "m" (*m) : "memory");

	return val;
}

#define __xchg_local(ptr, x, size) \
({ \
	unsigned long __xchg__res; \
	volatile void *__xchg__ptr = (ptr); \
	switch (size) { \
		case 1: __xchg__res = __xchg_u8_local(__xchg__ptr, x); break; \
		case 2: __xchg__res = __xchg_u16_local(__xchg__ptr, x); break; \
		case 4: __xchg__res = __xchg_u32_local(__xchg__ptr, x); break; \
		case 8: __xchg__res = __xchg_u64_local(__xchg__ptr, x); break; \
		default: __xchg_called_with_bad_pointer(); __xchg__res = x; \
	} \
	__xchg__res; \
})

#define xchg_local(ptr,x)						     \
  ({									     \
     __typeof__(*(ptr)) _x_ = (x);					     \
     (__typeof__(*(ptr))) __xchg_local((ptr), (unsigned long)_x_,	     \
     		sizeof(*(ptr))); \
  })

/* 
 * 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.
 *
 * The memory barrier should be placed in SMP only when we actually
 * make the change. If we don't change anything (so if the returned
 * prev is equal to old) then we aren't acquiring anything new and
 * we don't need any memory barrier as far I can tell.
 */

#define __HAVE_ARCH_CMPXCHG 1

static inline unsigned long
__cmpxchg_u8(volatile char *m, long old, long new)
{
	unsigned long prev, tmp, cmp, addr64;

	__asm__ __volatile__(
	"	andnot	%5,7,%4\n"
	"	insbl	%1,%5,%1\n"
	"1:	ldq_l	%2,0(%4)\n"
	"	extbl	%2,%5,%0\n"
	"	cmpeq	%0,%6,%3\n"
	"	beq	%3,2f\n"
	"	mskbl	%2,%5,%2\n"
	"	or	%1,%2,%2\n"
	"	stq_c	%2,0(%4)\n"
	"	beq	%2,3f\n"
#ifdef CONFIG_SMP
	"	mb\n"
#endif
	"2:\n"
	".subsection 2\n"
	"3:	br	1b\n"
	".previous"
	: "=&r" (prev), "=&r" (new), "=&r" (tmp), "=&r" (cmp), "=&r" (addr64)
	: "r" ((long)m), "Ir" (old), "1" (new) : "memory");

	return prev;
}

static inline unsigned long
__cmpxchg_u16(volatile short *m, long old, long new)
{
	unsigned long prev, tmp, cmp, addr64;

	__asm__ __volatile__(
	"	andnot	%5,7,%4\n"
	"	inswl	%1,%5,%1\n"
	"1:	ldq_l	%2,0(%4)\n"
	"	extwl	%2,%5,%0\n"
	"	cmpeq	%0,%6,%3\n"
	"	beq	%3,2f\n"
	"	mskwl	%2,%5,%2\n"
	"	or	%1,%2,%2\n"
	"	stq_c	%2,0(%4)\n"
	"	beq	%2,3f\n"
#ifdef CONFIG_SMP
	"	mb\n"
#endif
	"2:\n"
	".subsection 2\n"
	"3:	br	1b\n"
	".previous"
	: "=&r" (prev), "=&r" (new), "=&r" (tmp), "=&r" (cmp), "=&r" (addr64)
	: "r" ((long)m), "Ir" (old), "1" (new) : "memory");

	return prev;
}

static inline unsigned long
__cmpxchg_u32(volatile int *m, int old, int new)
{
	unsigned long prev, cmp;

	__asm__ __volatile__(
	"1:	ldl_l %0,%5\n"
	"	cmpeq %0,%3,%1\n"
	"	beq %1,2f\n"
	"	mov %4,%1\n"
	"	stl_c %1,%2\n"
	"	beq %1,3f\n"
#ifdef CONFIG_SMP
	"	mb\n"
#endif
	"2:\n"
	".subsection 2\n"
	"3:	br 1b\n"
	".previous"
	: "=&r"(prev), "=&r"(cmp), "=m"(*m)
	: "r"((long) old), "r"(new), "m"(*m) : "memory");

	return prev;
}

static inline unsigned long
__cmpxchg_u64(volatile long *m, unsigned long old, unsigned long new)
{
	unsigned long prev, cmp;

	__asm__ __volatile__(
	"1:	ldq_l %0,%5\n"
	"	cmpeq %0,%3,%1\n"
	"	beq %1,2f\n"
	"	mov %4,%1\n"
	"	stq_c %1,%2\n"
	"	beq %1,3f\n"
#ifdef CONFIG_SMP
	"	mb\n"
#endif
	"2:\n"
	".subsection 2\n"
	"3:	br 1b\n"
	".previous"
	: "=&r"(prev), "=&r"(cmp), "=m"(*m)
	: "r"((long) old), "r"(new), "m"(*m) : "memory");

	return prev;
}

/* This function doesn't exist, so you'll get a linker error
   if something tries to do an invalid cmpxchg().  */
extern void __cmpxchg_called_with_bad_pointer(void);

static __always_inline unsigned long
__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
{
	switch (size) {
		case 1:
			return __cmpxchg_u8(ptr, old, new);
		case 2:
			return __cmpxchg_u16(ptr, old, new);
		case 4:
			return __cmpxchg_u32(ptr, old, new);
		case 8:
			return __cmpxchg_u64(ptr, old, new);
	}
	__cmpxchg_called_with_bad_pointer();
	return old;
}

#define cmpxchg(ptr,o,n)						 \
  ({									 \
     __typeof__(*(ptr)) _o_ = (o);					 \
     __typeof__(*(ptr)) _n_ = (n);					 \
     (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,		 \
				    (unsigned long)_n_, sizeof(*(ptr))); \
  })

static inline unsigned long
__cmpxchg_u8_local(volatile char *m, long old, long new)
{
	unsigned long prev, tmp, cmp, addr64;

	__asm__ __volatile__(
	"	andnot	%5,7,%4\n"
	"	insbl	%1,%5,%1\n"
	"1:	ldq_l	%2,0(%4)\n"
	"	extbl	%2,%5,%0\n"
	"	cmpeq	%0,%6,%3\n"
	"	beq	%3,2f\n"
	"	mskbl	%2,%5,%2\n"
	"	or	%1,%2,%2\n"
	"	stq_c	%2,0(%4)\n"
	"	beq	%2,3f\n"
	"2:\n"
	".subsection 2\n"
	"3:	br	1b\n"
	".previous"
	: "=&r" (prev), "=&r" (new), "=&r" (tmp), "=&r" (cmp), "=&r" (addr64)
	: "r" ((long)m), "Ir" (old), "1" (new) : "memory");

	return prev;
}

static inline unsigned long
__cmpxchg_u16_local(volatile short *m, long old, long new)
{
	unsigned long prev, tmp, cmp, addr64;

	__asm__ __volatile__(
	"	andnot	%5,7,%4\n"
	"	inswl	%1,%5,%1\n"
	"1:	ldq_l	%2,0(%4)\n"
	"	extwl	%2,%5,%0\n"
	"	cmpeq	%0,%6,%3\n"
	"	beq	%3,2f\n"
	"	mskwl	%2,%5,%2\n"
	"	or	%1,%2,%2\n"
	"	stq_c	%2,0(%4)\n"
	"	beq	%2,3f\n"
	"2:\n"
	".subsection 2\n"
	"3:	br	1b\n"
	".previous"
	: "=&r" (prev), "=&r" (new), "=&r" (tmp), "=&r" (cmp), "=&r" (addr64)
	: "r" ((long)m), "Ir" (old), "1" (new) : "memory");

	return prev;
}

static inline unsigned long
__cmpxchg_u32_local(volatile int *m, int old, int new)
{
	unsigned long prev, cmp;

	__asm__ __volatile__(
	"1:	ldl_l %0,%5\n"
	"	cmpeq %0,%3,%1\n"
	"	beq %1,2f\n"
	"	mov %4,%1\n"
	"	stl_c %1,%2\n"
	"	beq %1,3f\n"
	"2:\n"
	".subsection 2\n"
	"3:	br 1b\n"
	".previous"
	: "=&r"(prev), "=&r"(cmp), "=m"(*m)
	: "r"((long) old), "r"(new), "m"(*m) : "memory");

	return prev;
}

static inline unsigned long
__cmpxchg_u64_local(volatile long *m, unsigned long old, unsigned long new)
{
	unsigned long prev, cmp;

	__asm__ __volatile__(
	"1:	ldq_l %0,%5\n"
	"	cmpeq %0,%3,%1\n"
	"	beq %1,2f\n"
	"	mov %4,%1\n"
	"	stq_c %1,%2\n"
	"	beq %1,3f\n"
	"2:\n"
	".subsection 2\n"
	"3:	br 1b\n"
	".previous"
	: "=&r"(prev), "=&r"(cmp), "=m"(*m)
	: "r"((long) old), "r"(new), "m"(*m) : "memory");

	return prev;
}

static __always_inline unsigned long
__cmpxchg_local(volatile void *ptr, unsigned long old, unsigned long new,
		int size)
{
	switch (size) {
		case 1:
			return __cmpxchg_u8_local(ptr, old, new);
		case 2:
			return __cmpxchg_u16_local(ptr, old, new);
		case 4:
			return __cmpxchg_u32_local(ptr, old, new);
		case 8:
			return __cmpxchg_u64_local(ptr, old, new);
	}
	__cmpxchg_called_with_bad_pointer();
	return old;
}

#define cmpxchg_local(ptr,o,n)						 \
  ({									 \
     __typeof__(*(ptr)) _o_ = (o);					 \
     __typeof__(*(ptr)) _n_ = (n);					 \
     (__typeof__(*(ptr))) __cmpxchg_local((ptr), (unsigned long)_o_,	 \
				    (unsigned long)_n_, sizeof(*(ptr))); \
  })

#endif /* __ASSEMBLY__ */

#define arch_align_stack(x) (x)

#endif