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    /*
     * bitops.h: Bit string operations on the ppc
     */
    
    #ifndef _PPC_BITOPS_H
    #define _PPC_BITOPS_H
    
    #include <linux/config.h>
    #include <asm/byteorder.h>
    
    extern void set_bit(int nr, volatile void *addr);
    extern void clear_bit(int nr, volatile void *addr);
    extern void change_bit(int nr, volatile void *addr);
    extern int test_and_set_bit(int nr, volatile void *addr);
    extern int test_and_clear_bit(int nr, volatile void *addr);
    extern int test_and_change_bit(int nr, volatile void *addr);
    
    /*
     * Arguably these bit operations don't imply any memory barrier or
     * SMP ordering, but in fact a lot of drivers expect them to imply
     * both, since they do on x86 cpus.
     */
    #ifdef CONFIG_SMP
    #define SMP_WMB		"eieio\n"
    #define SMP_MB		"\nsync"
    #else
    #define SMP_WMB
    #define SMP_MB
    #endif /* CONFIG_SMP */
    
    #define __INLINE_BITOPS	1
    
    #if __INLINE_BITOPS
    /*
     * These used to be if'd out here because using : "cc" as a constraint
     * resulted in errors from egcs.  Things may be OK with gcc-2.95.
     */
    extern __inline__ void set_bit(int nr, volatile void * addr)
    {
    	unsigned long old;
    	unsigned long mask = 1 << (nr & 0x1f);
    	unsigned long *p = ((unsigned long *)addr) + (nr >> 5);
    
    	__asm__ __volatile__(SMP_WMB "\
    1:	lwarx	%0,0,%3\n\
    	or	%0,%0,%2\n\
    	stwcx.	%0,0,%3\n\
    	bne	1b"
    	SMP_MB
    	: "=&r" (old), "=m" (*p)
    	: "r" (mask), "r" (p), "m" (*p)
    	: "cc" );
    }
    
    extern __inline__ void clear_bit(int nr, volatile void *addr)
    {
    	unsigned long old;
    	unsigned long mask = 1 << (nr & 0x1f);
    	unsigned long *p = ((unsigned long *)addr) + (nr >> 5);
    
    	__asm__ __volatile__(SMP_WMB "\
    1:	lwarx	%0,0,%3\n\
    	andc	%0,%0,%2\n\
    	stwcx.	%0,0,%3\n\
    	bne	1b"
    	SMP_MB
    	: "=&r" (old), "=m" (*p)
    	: "r" (mask), "r" (p), "m" (*p)
    	: "cc");
    }
    
    extern __inline__ void change_bit(int nr, volatile void *addr)
    {
    	unsigned long old;
    	unsigned long mask = 1 << (nr & 0x1f);
    	unsigned long *p = ((unsigned long *)addr) + (nr >> 5);
    
    	__asm__ __volatile__(SMP_WMB "\
    1:	lwarx	%0,0,%3\n\
    	xor	%0,%0,%2\n\
    	stwcx.	%0,0,%3\n\
    	bne	1b"
    	SMP_MB
    	: "=&r" (old), "=m" (*p)
    	: "r" (mask), "r" (p), "m" (*p)
    	: "cc");
    }
    
    extern __inline__ int test_and_set_bit(int nr, volatile void *addr)
    {
    	unsigned int old, t;
    	unsigned int mask = 1 << (nr & 0x1f);
    	volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5);
    
    	__asm__ __volatile__(SMP_WMB "\
    1:	lwarx	%0,0,%4\n\
    	or	%1,%0,%3\n\
    	stwcx.	%1,0,%4\n\
    	bne	1b"
    	SMP_MB
    	: "=&r" (old), "=&r" (t), "=m" (*p)
    	: "r" (mask), "r" (p), "m" (*p)
    	: "cc");
    
    	return (old & mask) != 0;
    }
    
    extern __inline__ int test_and_clear_bit(int nr, volatile void *addr)
    {
    	unsigned int old, t;
    	unsigned int mask = 1 << (nr & 0x1f);
    	volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5);
    
    	__asm__ __volatile__(SMP_WMB "\
    1:	lwarx	%0,0,%4\n\
    	andc	%1,%0,%3\n\
    	stwcx.	%1,0,%4\n\
    	bne	1b"
    	SMP_MB
    	: "=&r" (old), "=&r" (t), "=m" (*p)
    	: "r" (mask), "r" (p), "m" (*p)
    	: "cc");
    
    	return (old & mask) != 0;
    }
    
    extern __inline__ int test_and_change_bit(int nr, volatile void *addr)
    {
    	unsigned int old, t;
    	unsigned int mask = 1 << (nr & 0x1f);
    	volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5);
    
    	__asm__ __volatile__(SMP_WMB "\
    1:	lwarx	%0,0,%4\n\
    	xor	%1,%0,%3\n\
    	stwcx.	%1,0,%4\n\
    	bne	1b"
    	SMP_MB
    	: "=&r" (old), "=&r" (t), "=m" (*p)
    	: "r" (mask), "r" (p), "m" (*p)
    	: "cc");
    
    	return (old & mask) != 0;
    }
    #endif /* __INLINE_BITOPS */
    
    extern __inline__ int test_bit(int nr, __const__ volatile void *addr)
    {
    	__const__ unsigned int *p = (__const__ unsigned int *) addr;
    
    	return ((p[nr >> 5] >> (nr & 0x1f)) & 1) != 0;
    }
    
    /* Return the bit position of the most significant 1 bit in a word */
    
    /* - the result is undefined when x == 0 */
    
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    extern __inline__ int __ilog2(unsigned int x)
    {
    	int lz;
    
    	asm ("cntlzw %0,%1" : "=r" (lz) : "r" (x));
    	return 31 - lz;
    }
    
    extern __inline__ int ffz(unsigned int x)
    {
    	if ((x = ~x) == 0)
    		return 32;
    	return __ilog2(x & -x);
    }
    
    
    /*
     * fls: find last (most-significant) bit set.
     * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
     *
     * On powerpc, __ilog2(0) returns -1, but this is not safe in general
     */
    static __inline__ int fls(unsigned int x)
    {
    	return __ilog2(x) + 1;
    }
    
    #define PLATFORM_FLS
    
    
    /**
     * fls64 - find last set bit in a 64-bit word
     * @x: the word to search
     *
     * This is defined in a similar way as the libc and compiler builtin
     * ffsll, but returns the position of the most significant set bit.
     *
     * fls64(value) returns 0 if value is 0 or the position of the last
     * set bit if value is nonzero. The last (most significant) bit is
     * at position 64.
     */
    #if BITS_PER_LONG == 32
    static inline int fls64(__u64 x)
    {
    	__u32 h = x >> 32;
    	if (h)
    		return fls(h) + 32;
    	return fls(x);
    }
    #elif BITS_PER_LONG == 64
    static inline int fls64(__u64 x)
    {
    	if (x == 0)
    		return 0;
    	return __ilog2(x) + 1;
    }
    #else
    #error BITS_PER_LONG not 32 or 64
    #endif
    
    static inline int __ilog2_u64(u64 n)
    {
    	return fls64(n) - 1;
    }
    
    static inline int ffs64(u64 x)
    {
    	return __ilog2_u64(x & -x) + 1ull;
    }
    
    
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    #ifdef __KERNEL__
    
    /*
     * ffs: find first bit set. This is defined the same way as
     * the libc and compiler builtin ffs routines, therefore
     * differs in spirit from the above ffz (man ffs).
     */
    extern __inline__ int ffs(int x)
    {
    	return __ilog2(x & -x) + 1;
    }
    
    #define PLATFORM_FFS
    
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    /*
     * hweightN: returns the hamming weight (i.e. the number
     * of bits set) of a N-bit word
     */
    
    #define hweight32(x) generic_hweight32(x)
    #define hweight16(x) generic_hweight16(x)
    #define hweight8(x) generic_hweight8(x)
    
    #endif /* __KERNEL__ */
    
    /*
     * This implementation of find_{first,next}_zero_bit was stolen from
     * Linus' asm-alpha/bitops.h.
     */
    #define find_first_zero_bit(addr, size) \
    	find_next_zero_bit((addr), (size), 0)
    
    extern __inline__ unsigned long find_next_zero_bit(void * addr,
    	unsigned long size, unsigned long offset)
    {
    	unsigned int * p = ((unsigned int *) addr) + (offset >> 5);
    	unsigned int result = offset & ~31UL;
    	unsigned int tmp;
    
    	if (offset >= size)
    		return size;
    	size -= result;
    	offset &= 31UL;
    	if (offset) {
    		tmp = *p++;
    		tmp |= ~0UL >> (32-offset);
    		if (size < 32)
    			goto found_first;
    		if (tmp != ~0U)
    			goto found_middle;
    		size -= 32;
    		result += 32;
    	}
    	while (size >= 32) {
    		if ((tmp = *p++) != ~0U)
    			goto found_middle;
    		result += 32;
    		size -= 32;
    	}
    	if (!size)
    		return result;
    	tmp = *p;
    found_first:
    	tmp |= ~0UL << size;
    found_middle:
    	return result + ffz(tmp);
    }
    
    
    #define _EXT2_HAVE_ASM_BITOPS_
    
    #ifdef __KERNEL__
    /*
     * test_and_{set,clear}_bit guarantee atomicity without
     * disabling interrupts.
     */
    #define ext2_set_bit(nr, addr)		test_and_set_bit((nr) ^ 0x18, addr)
    #define ext2_clear_bit(nr, addr)	test_and_clear_bit((nr) ^ 0x18, addr)
    
    #else
    extern __inline__ int ext2_set_bit(int nr, void * addr)
    {
    	int		mask;
    	unsigned char	*ADDR = (unsigned char *) addr;
    	int oldbit;
    
    	ADDR += nr >> 3;
    	mask = 1 << (nr & 0x07);
    	oldbit = (*ADDR & mask) ? 1 : 0;
    	*ADDR |= mask;
    	return oldbit;
    }
    
    extern __inline__ int ext2_clear_bit(int nr, void * addr)
    {
    	int		mask;
    	unsigned char	*ADDR = (unsigned char *) addr;
    	int oldbit;
    
    	ADDR += nr >> 3;
    	mask = 1 << (nr & 0x07);
    	oldbit = (*ADDR & mask) ? 1 : 0;
    	*ADDR = *ADDR & ~mask;
    	return oldbit;
    }
    #endif	/* __KERNEL__ */
    
    extern __inline__ int ext2_test_bit(int nr, __const__ void * addr)
    {
    	__const__ unsigned char	*ADDR = (__const__ unsigned char *) addr;
    
    	return (ADDR[nr >> 3] >> (nr & 7)) & 1;
    }
    
    /*
     * This implementation of ext2_find_{first,next}_zero_bit was stolen from
     * Linus' asm-alpha/bitops.h and modified for a big-endian machine.
     */
    
    #define ext2_find_first_zero_bit(addr, size) \
    
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    	ext2_find_next_zero_bit((addr), (size), 0)
    
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    static __inline__ unsigned long ext2_find_next_zero_bit(void *addr,
    
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    	unsigned long size, unsigned long offset)
    {
    	unsigned int *p = ((unsigned int *) addr) + (offset >> 5);
    	unsigned int result = offset & ~31UL;
    	unsigned int tmp;
    
    	if (offset >= size)
    		return size;
    	size -= result;
    	offset &= 31UL;
    	if (offset) {
    		tmp = cpu_to_le32p(p++);
    		tmp |= ~0UL >> (32-offset);
    		if (size < 32)
    			goto found_first;
    		if (tmp != ~0U)
    			goto found_middle;
    		size -= 32;
    		result += 32;
    	}
    	while (size >= 32) {
    		if ((tmp = cpu_to_le32p(p++)) != ~0U)
    			goto found_middle;
    		result += 32;
    		size -= 32;
    	}
    	if (!size)
    		return result;
    	tmp = cpu_to_le32p(p);
    found_first:
    	tmp |= ~0U << size;
    found_middle:
    	return result + ffz(tmp);
    }
    
    /* Bitmap functions for the minix filesystem.  */
    #define minix_test_and_set_bit(nr,addr) ext2_set_bit(nr,addr)
    #define minix_set_bit(nr,addr) ((void)ext2_set_bit(nr,addr))
    #define minix_test_and_clear_bit(nr,addr) ext2_clear_bit(nr,addr)
    #define minix_test_bit(nr,addr) ext2_test_bit(nr,addr)
    #define minix_find_first_zero_bit(addr,size) ext2_find_first_zero_bit(addr,size)
    
    #endif /* _PPC_BITOPS_H */