458 lines
17 KiB
C
458 lines
17 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#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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#include <linux/kernel.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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* DOC: bitmap overview
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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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* ::
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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_set(dst, pos, nbits) Set specified bit area
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* bitmap_clear(dst, pos, nbits) Clear specified bit area
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* bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area
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* bitmap_find_next_zero_area_off(buf, len, pos, n, mask) as above
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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_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap
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* bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz
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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_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf
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* bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf
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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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* bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst
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* bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst
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*
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* Note, bitmap_zero() and bitmap_fill() operate over the region of
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* unsigned longs, that is, bits behind bitmap till the unsigned long
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* boundary will be zeroed or filled as well. Consider to use
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* bitmap_clear() or bitmap_set() to make explicit zeroing or filling
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* respectively.
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*/
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/**
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* DOC: bitmap bitops
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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)
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* 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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* find_next_and_bit(addr1, addr2, nbits, bit)
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* Same as find_next_bit, but in
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* (*addr1 & *addr2)
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*
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*/
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/**
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* DOC: declare bitmap
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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, unsigned int nbits);
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extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
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extern int __bitmap_equal(const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int nbits);
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extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
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unsigned int nbits);
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extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
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unsigned int shift, unsigned int nbits);
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extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
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unsigned int shift, unsigned int nbits);
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extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int nbits);
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extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int nbits);
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extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int nbits);
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extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int nbits);
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extern int __bitmap_intersects(const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int nbits);
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extern int __bitmap_subset(const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int nbits);
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extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
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extern void __bitmap_set(unsigned long *map, unsigned int start, int len);
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extern void __bitmap_clear(unsigned long *map, unsigned int start, int len);
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extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
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unsigned long size,
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unsigned long start,
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unsigned int nr,
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unsigned long align_mask,
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unsigned long align_offset);
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/**
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* bitmap_find_next_zero_area - find a contiguous aligned zero area
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* @map: The address to base the search on
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* @size: The bitmap size in bits
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* @start: The bitnumber to start searching at
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* @nr: The number of zeroed bits we're looking for
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* @align_mask: Alignment mask for zero area
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*
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* The @align_mask should be one less than a power of 2; the effect is that
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* the bit offset of all zero areas this function finds is multiples of that
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* power of 2. A @align_mask of 0 means no alignment is required.
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*/
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static inline unsigned long
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bitmap_find_next_zero_area(unsigned long *map,
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unsigned long size,
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unsigned long start,
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unsigned int nr,
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unsigned long align_mask)
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{
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return bitmap_find_next_zero_area_off(map, size, start, nr,
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align_mask, 0);
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}
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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_parselist(const char *buf, unsigned long *maskp,
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int nmaskbits);
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extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
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unsigned long *dst, int nbits);
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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, unsigned int nbits);
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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 void bitmap_onto(unsigned long *dst, const unsigned long *orig,
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const unsigned long *relmap, unsigned int bits);
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extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
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unsigned int sz, unsigned int nbits);
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extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
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extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
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extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
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#ifdef __BIG_ENDIAN
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extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
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#else
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#define bitmap_copy_le bitmap_copy
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#endif
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extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
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extern int bitmap_print_to_pagebuf(bool list, char *buf,
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const unsigned long *maskp, int nmaskbits);
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#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
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#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
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#define small_const_nbits(nbits) \
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(__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
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static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
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{
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if (small_const_nbits(nbits))
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*dst = 0UL;
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else {
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unsigned 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, unsigned int nbits)
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{
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if (small_const_nbits(nbits))
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*dst = ~0UL;
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else {
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unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
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memset(dst, 0xff, len);
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}
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}
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static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
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unsigned int nbits)
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{
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if (small_const_nbits(nbits))
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*dst = *src;
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else {
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unsigned 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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/*
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* Copy bitmap and clear tail bits in last word.
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*/
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static inline void bitmap_copy_clear_tail(unsigned long *dst,
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const unsigned long *src, unsigned int nbits)
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{
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bitmap_copy(dst, src, nbits);
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if (nbits % BITS_PER_LONG)
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dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits);
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}
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/*
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* On 32-bit systems bitmaps are represented as u32 arrays internally, and
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* therefore conversion is not needed when copying data from/to arrays of u32.
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*/
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#if BITS_PER_LONG == 64
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extern void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf,
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unsigned int nbits);
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extern void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap,
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unsigned int nbits);
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#else
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#define bitmap_from_arr32(bitmap, buf, nbits) \
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bitmap_copy_clear_tail((unsigned long *) (bitmap), \
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(const unsigned long *) (buf), (nbits))
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#define bitmap_to_arr32(buf, bitmap, nbits) \
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bitmap_copy_clear_tail((unsigned long *) (buf), \
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(const unsigned long *) (bitmap), (nbits))
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#endif
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static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
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const unsigned long *src2, unsigned int nbits)
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{
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if (small_const_nbits(nbits))
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return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
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return __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, unsigned int nbits)
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{
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if (small_const_nbits(nbits))
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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, unsigned int nbits)
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{
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if (small_const_nbits(nbits))
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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 int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
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const unsigned long *src2, unsigned int nbits)
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{
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if (small_const_nbits(nbits))
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return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
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return __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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unsigned int nbits)
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{
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if (small_const_nbits(nbits))
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*dst = ~(*src);
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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, unsigned int nbits)
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{
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if (small_const_nbits(nbits))
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return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
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if (__builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8))
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return !memcmp(src1, src2, nbits / 8);
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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, unsigned int nbits)
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{
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if (small_const_nbits(nbits))
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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, unsigned int nbits)
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{
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if (small_const_nbits(nbits))
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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, unsigned nbits)
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{
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if (small_const_nbits(nbits))
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return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
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return find_first_bit(src, nbits) == nbits;
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}
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static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
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{
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if (small_const_nbits(nbits))
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return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
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return find_first_zero_bit(src, nbits) == nbits;
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}
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static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
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{
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if (small_const_nbits(nbits))
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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 __always_inline void bitmap_set(unsigned long *map, unsigned int start,
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unsigned int nbits)
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{
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if (__builtin_constant_p(nbits) && nbits == 1)
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__set_bit(start, map);
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else if (__builtin_constant_p(start & 7) && IS_ALIGNED(start, 8) &&
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__builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8))
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memset((char *)map + start / 8, 0xff, nbits / 8);
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else
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__bitmap_set(map, start, nbits);
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}
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static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
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unsigned int nbits)
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{
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if (__builtin_constant_p(nbits) && nbits == 1)
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__clear_bit(start, map);
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else if (__builtin_constant_p(start & 7) && IS_ALIGNED(start, 8) &&
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__builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8))
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memset((char *)map + start / 8, 0, nbits / 8);
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else
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__bitmap_clear(map, start, nbits);
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}
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static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
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unsigned int shift, int nbits)
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{
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if (small_const_nbits(nbits))
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*dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
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else
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__bitmap_shift_right(dst, src, shift, nbits);
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}
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static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
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unsigned int shift, unsigned int nbits)
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{
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if (small_const_nbits(nbits))
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*dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
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else
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__bitmap_shift_left(dst, src, shift, 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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/**
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* BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
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* @n: u64 value
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*
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* Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
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* integers in 32-bit environment, and 64-bit integers in 64-bit one.
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*
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* There are four combinations of endianness and length of the word in linux
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* ABIs: LE64, BE64, LE32 and BE32.
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*
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* On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
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* bitmaps and therefore don't require any special handling.
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*
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* On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
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* prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
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* other hand is represented as an array of 32-bit words and the position of
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* bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
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* word. For example, bit #42 is located at 10th position of 2nd word.
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* It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
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* values in memory as it usually does. But for BE we need to swap hi and lo
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* words manually.
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*
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* With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
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* lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
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* hi and lo words, as is expected by bitmap.
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*/
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#if __BITS_PER_LONG == 64
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#define BITMAP_FROM_U64(n) (n)
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#else
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#define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
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((unsigned long) ((u64)(n) >> 32))
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#endif
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/**
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* bitmap_from_u64 - Check and swap words within u64.
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* @mask: source bitmap
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* @dst: destination bitmap
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*
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* In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]``
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* to read u64 mask, we will get the wrong word.
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* That is ``(u32 *)(&val)[0]`` gets the upper 32 bits,
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* but we expect the lower 32-bits of u64.
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*/
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static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
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{
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dst[0] = mask & ULONG_MAX;
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if (sizeof(mask) > sizeof(unsigned long))
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dst[1] = mask >> 32;
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}
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#endif /* __ASSEMBLY__ */
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#endif /* __LINUX_BITMAP_H */
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