forked from mirrors/linux
		
	lib/bitmap.c:bitmap_parse() is a library function that received as input a user buffer. This seemed to have originated from the way the write_proc function of the /proc filesystem operates. This has been reworked to not use kmalloc and eliminates a lot of get_user() overhead by performing one access_ok before using __get_user(). We need to test if we are in kernel or user space (is_user) and access the buffer differently. We cannot use __get_user() to access kernel addresses in all cases, for example in architectures with separate address space for kernel and user. This function will be useful for other uses as well; for example, taking input for /sysfs instead of /proc, so it was changed to accept kernel buffers. We have this use for the Linux UWB project, as part as the upcoming bandwidth allocator code. Only a few routines used this function and they were changed too. Signed-off-by: Reinette Chatre <reinette.chatre@linux.intel.com> Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com> Cc: Paul Jackson <pj@sgi.com> Cc: Joe Korty <joe.korty@ccur.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
		
			
				
	
	
		
			284 lines
		
	
	
	
		
			9.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			284 lines
		
	
	
	
		
			9.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
#ifndef __LINUX_BITMAP_H
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#define __LINUX_BITMAP_H
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#ifndef __ASSEMBLY__
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#include <linux/types.h>
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#include <linux/bitops.h>
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#include <linux/string.h>
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/*
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 * bitmaps provide bit arrays that consume one or more unsigned
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 * longs.  The bitmap interface and available operations are listed
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 * here, in bitmap.h
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 *
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 * Function implementations generic to all architectures are in
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 * lib/bitmap.c.  Functions implementations that are architecture
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 * specific are in various include/asm-<arch>/bitops.h headers
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 * and other arch/<arch> specific files.
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 *
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 * See lib/bitmap.c for more details.
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 */
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/*
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 * The available bitmap operations and their rough meaning in the
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 * case that the bitmap is a single unsigned long are thus:
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 *
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 * Note that nbits should be always a compile time evaluable constant.
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 * Otherwise many inlines will generate horrible code.
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 *
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 * bitmap_zero(dst, nbits)			*dst = 0UL
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 * bitmap_fill(dst, nbits)			*dst = ~0UL
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 * bitmap_copy(dst, src, nbits)			*dst = *src
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 * bitmap_and(dst, src1, src2, nbits)		*dst = *src1 & *src2
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 * bitmap_or(dst, src1, src2, nbits)		*dst = *src1 | *src2
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 * bitmap_xor(dst, src1, src2, nbits)		*dst = *src1 ^ *src2
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 * bitmap_andnot(dst, src1, src2, nbits)	*dst = *src1 & ~(*src2)
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 * bitmap_complement(dst, src, nbits)		*dst = ~(*src)
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 * bitmap_equal(src1, src2, nbits)		Are *src1 and *src2 equal?
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 * bitmap_intersects(src1, src2, nbits) 	Do *src1 and *src2 overlap?
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 * bitmap_subset(src1, src2, nbits)		Is *src1 a subset of *src2?
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 * bitmap_empty(src, nbits)			Are all bits zero in *src?
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 * bitmap_full(src, nbits)			Are all bits set in *src?
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 * bitmap_weight(src, nbits)			Hamming Weight: number set bits
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 * bitmap_shift_right(dst, src, n, nbits)	*dst = *src >> n
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 * bitmap_shift_left(dst, src, n, nbits)	*dst = *src << n
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 * bitmap_remap(dst, src, old, new, nbits)	*dst = map(old, new)(src)
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 * bitmap_bitremap(oldbit, old, new, nbits)	newbit = map(old, new)(oldbit)
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 * bitmap_scnprintf(buf, len, src, nbits)	Print bitmap src to buf
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 * bitmap_parse(buf, buflen, dst, nbits)	Parse bitmap dst from kernel buf
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 * bitmap_parse_user(ubuf, ulen, dst, nbits)	Parse bitmap dst from user buf
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 * bitmap_scnlistprintf(buf, len, src, nbits)	Print bitmap src as list to buf
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 * bitmap_parselist(buf, dst, nbits)		Parse bitmap dst from list
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 * bitmap_find_free_region(bitmap, bits, order)	Find and allocate bit region
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 * bitmap_release_region(bitmap, pos, order)	Free specified bit region
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 * bitmap_allocate_region(bitmap, pos, order)	Allocate specified bit region
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 */
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/*
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 * Also the following operations in asm/bitops.h apply to bitmaps.
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 *
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 * set_bit(bit, addr)			*addr |= bit
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 * clear_bit(bit, addr)			*addr &= ~bit
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 * change_bit(bit, addr)		*addr ^= bit
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 * test_bit(bit, addr)			Is bit set in *addr?
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 * test_and_set_bit(bit, addr)		Set bit and return old value
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 * test_and_clear_bit(bit, addr)	Clear bit and return old value
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 * test_and_change_bit(bit, addr)	Change bit and return old value
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 * find_first_zero_bit(addr, nbits)	Position first zero bit in *addr
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 * find_first_bit(addr, nbits)		Position first set bit in *addr
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 * find_next_zero_bit(addr, nbits, bit)	Position next zero bit in *addr >= bit
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 * find_next_bit(addr, nbits, bit)	Position next set bit in *addr >= bit
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 */
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/*
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 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
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 * to declare an array named 'name' of just enough unsigned longs to
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 * contain all bit positions from 0 to 'bits' - 1.
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 */
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/*
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 * lib/bitmap.c provides these functions:
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 */
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extern int __bitmap_empty(const unsigned long *bitmap, int bits);
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extern int __bitmap_full(const unsigned long *bitmap, int bits);
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extern int __bitmap_equal(const unsigned long *bitmap1,
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                	const unsigned long *bitmap2, int bits);
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extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
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			int bits);
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extern void __bitmap_shift_right(unsigned long *dst,
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                        const unsigned long *src, int shift, int bits);
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extern void __bitmap_shift_left(unsigned long *dst,
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                        const unsigned long *src, int shift, int bits);
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extern void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
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			const unsigned long *bitmap2, int bits);
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extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
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			const unsigned long *bitmap2, int bits);
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extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
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			const unsigned long *bitmap2, int bits);
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extern void __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
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			const unsigned long *bitmap2, int bits);
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extern int __bitmap_intersects(const unsigned long *bitmap1,
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			const unsigned long *bitmap2, int bits);
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extern int __bitmap_subset(const unsigned long *bitmap1,
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			const unsigned long *bitmap2, int bits);
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extern int __bitmap_weight(const unsigned long *bitmap, int bits);
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extern int bitmap_scnprintf(char *buf, unsigned int len,
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			const unsigned long *src, int nbits);
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extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
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			unsigned long *dst, int nbits);
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extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
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			unsigned long *dst, int nbits);
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extern int bitmap_scnlistprintf(char *buf, unsigned int len,
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			const unsigned long *src, int nbits);
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extern int bitmap_parselist(const char *buf, unsigned long *maskp,
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			int nmaskbits);
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extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
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		const unsigned long *old, const unsigned long *new, int bits);
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extern int bitmap_bitremap(int oldbit,
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		const unsigned long *old, const unsigned long *new, int bits);
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extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
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extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
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extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
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#define BITMAP_LAST_WORD_MASK(nbits)					\
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(									\
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	((nbits) % BITS_PER_LONG) ?					\
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		(1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL		\
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)
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static inline void bitmap_zero(unsigned long *dst, int nbits)
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{
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	if (nbits <= BITS_PER_LONG)
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		*dst = 0UL;
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	else {
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		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
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		memset(dst, 0, len);
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	}
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}
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static inline void bitmap_fill(unsigned long *dst, int nbits)
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{
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	size_t nlongs = BITS_TO_LONGS(nbits);
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	if (nlongs > 1) {
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		int len = (nlongs - 1) * sizeof(unsigned long);
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		memset(dst, 0xff,  len);
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	}
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	dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
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}
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static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
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			int nbits)
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{
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	if (nbits <= BITS_PER_LONG)
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		*dst = *src;
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	else {
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		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
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		memcpy(dst, src, len);
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	}
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}
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static inline void bitmap_and(unsigned long *dst, const unsigned long *src1,
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			const unsigned long *src2, int nbits)
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{
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	if (nbits <= BITS_PER_LONG)
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		*dst = *src1 & *src2;
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	else
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		__bitmap_and(dst, src1, src2, nbits);
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}
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static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
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			const unsigned long *src2, int nbits)
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{
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	if (nbits <= BITS_PER_LONG)
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		*dst = *src1 | *src2;
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	else
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		__bitmap_or(dst, src1, src2, nbits);
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}
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static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
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			const unsigned long *src2, int nbits)
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{
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	if (nbits <= BITS_PER_LONG)
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		*dst = *src1 ^ *src2;
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	else
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		__bitmap_xor(dst, src1, src2, nbits);
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}
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static inline void bitmap_andnot(unsigned long *dst, const unsigned long *src1,
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			const unsigned long *src2, int nbits)
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{
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	if (nbits <= BITS_PER_LONG)
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		*dst = *src1 & ~(*src2);
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	else
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		__bitmap_andnot(dst, src1, src2, nbits);
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}
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static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
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			int nbits)
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{
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	if (nbits <= BITS_PER_LONG)
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		*dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
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	else
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		__bitmap_complement(dst, src, nbits);
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}
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static inline int bitmap_equal(const unsigned long *src1,
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			const unsigned long *src2, int nbits)
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{
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	if (nbits <= BITS_PER_LONG)
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		return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
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	else
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		return __bitmap_equal(src1, src2, nbits);
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}
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static inline int bitmap_intersects(const unsigned long *src1,
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			const unsigned long *src2, int nbits)
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{
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	if (nbits <= BITS_PER_LONG)
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		return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
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	else
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		return __bitmap_intersects(src1, src2, nbits);
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}
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static inline int bitmap_subset(const unsigned long *src1,
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			const unsigned long *src2, int nbits)
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{
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	if (nbits <= BITS_PER_LONG)
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		return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
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	else
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		return __bitmap_subset(src1, src2, nbits);
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}
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static inline int bitmap_empty(const unsigned long *src, int nbits)
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{
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	if (nbits <= BITS_PER_LONG)
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		return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
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	else
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		return __bitmap_empty(src, nbits);
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}
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static inline int bitmap_full(const unsigned long *src, int nbits)
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{
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	if (nbits <= BITS_PER_LONG)
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		return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
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	else
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		return __bitmap_full(src, nbits);
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}
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static inline int bitmap_weight(const unsigned long *src, int nbits)
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{
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	if (nbits <= BITS_PER_LONG)
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		return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
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	return __bitmap_weight(src, nbits);
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}
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static inline void bitmap_shift_right(unsigned long *dst,
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			const unsigned long *src, int n, int nbits)
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{
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	if (nbits <= BITS_PER_LONG)
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		*dst = *src >> n;
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	else
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		__bitmap_shift_right(dst, src, n, nbits);
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}
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static inline void bitmap_shift_left(unsigned long *dst,
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			const unsigned long *src, int n, int nbits)
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{
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	if (nbits <= BITS_PER_LONG)
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		*dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
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	else
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		__bitmap_shift_left(dst, src, n, nbits);
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}
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static inline int bitmap_parse(const char *buf, unsigned int buflen,
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			unsigned long *maskp, int nmaskbits)
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{
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	return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
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}
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#endif /* __ASSEMBLY__ */
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#endif /* __LINUX_BITMAP_H */
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