arch/sparc: Introduce cmpxchg_u8 SPARC

	return new;

}

/*

 * Use 4 byte cas instruction to achieve 1 byte cmpxchg. Main logic

 * here is to get the bit shift of the byte we are interested in.

 * The XOR is handy for reversing the bits for big-endian byte order

 */

static inline unsigned long

__cmpxchg_u8(volatile unsigned char *m, unsigned char old, unsigned char new)

{

	unsigned long maddr = (unsigned long)m;

	int bit_shift = (((unsigned long)m & 3) ^ 3) << 3;

	unsigned int mask = 0xff << bit_shift;

	unsigned int *ptr = (unsigned int *) (maddr & ~3);

	unsigned int old32, new32, load;

	unsigned int load32 = *ptr;

	do {

		new32 = (load32 & ~mask) | (new << bit_shift);

		old32 = (load32 & ~mask) | (old << bit_shift);

		load32 = __cmpxchg_u32(ptr, old32, new32);

		if (load32 == old32)

			return old;

		load = (load32 & mask) >> bit_shift;

	} while (load == old);

	return load;

}

/* This function doesn't exist, so you'll get a linker error

   if something tries to do an invalid cmpxchg().  */

void __cmpxchg_called_with_bad_pointer(void);

__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)

{

	switch (size) {

		case 1:

			return __cmpxchg_u8(ptr, old, new);

		case 4:

			return __cmpxchg_u32(ptr, old, new);

		case 8: