include/linux/bitmap.h

Source file repositories/reference/linux-study-clean/include/linux/bitmap.h

File Facts

System
Linux kernel
Corpus path
include/linux/bitmap.h
Extension
.h
Size
31975 bytes
Lines
900
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef __LINUX_BITMAP_H
#define __LINUX_BITMAP_H

#ifndef __ASSEMBLY__

#include <linux/align.h>
#include <linux/bitops.h>
#include <linux/cleanup.h>
#include <linux/errno.h>
#include <linux/find.h>
#include <linux/limits.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/bitmap-str.h>

struct device;

/*
 * bitmaps provide bit arrays that consume one or more unsigned
 * longs.  The bitmap interface and available operations are listed
 * here, in bitmap.h
 *
 * Function implementations generic to all architectures are in
 * lib/bitmap.c.  Functions implementations that are architecture
 * specific are in various arch/<arch>/include/asm/bitops.h headers
 * and other arch/<arch> specific files.
 *
 * See lib/bitmap.c for more details.
 */

/**
 * DOC: bitmap overview
 *
 * The available bitmap operations and their rough meaning in the
 * case that the bitmap is a single unsigned long are thus:
 *
 * The generated code is more efficient when nbits is known at
 * compile-time and at most BITS_PER_LONG.
 *
 * ::
 *
 *  bitmap_zero(dst, nbits)                     *dst = 0UL
 *  bitmap_fill(dst, nbits)                     *dst = ~0UL
 *  bitmap_copy(dst, src, nbits)                *dst = *src
 *  bitmap_and(dst, src1, src2, nbits)          *dst = *src1 & *src2
 *  bitmap_or(dst, src1, src2, nbits)           *dst = *src1 | *src2
 *  bitmap_weighted_or(dst, src1, src2, nbits)	*dst = *src1 | *src2. Returns Hamming Weight of dst
 *  bitmap_weighted_xor(dst, src1, src2, nbits)	*dst = *src1 ^ *src2. Returns Hamming Weight of dst
 *  bitmap_xor(dst, src1, src2, nbits)          *dst = *src1 ^ *src2
 *  bitmap_andnot(dst, src1, src2, nbits)       *dst = *src1 & ~(*src2)
 *  bitmap_complement(dst, src, nbits)          *dst = ~(*src)
 *  bitmap_equal(src1, src2, nbits)             Are *src1 and *src2 equal?
 *  bitmap_intersects(src1, src2, nbits)        Do *src1 and *src2 overlap?
 *  bitmap_subset(src1, src2, nbits)            Is *src1 a subset of *src2?
 *  bitmap_empty(src, nbits)                    Are all bits zero in *src?
 *  bitmap_full(src, nbits)                     Are all bits set in *src?
 *  bitmap_weight(src, nbits)                   Hamming Weight: number set bits
 *  bitmap_weight_and(src1, src2, nbits)        Hamming Weight of and'ed bitmap
 *  bitmap_weight_andnot(src1, src2, nbits)     Hamming Weight of andnot'ed bitmap
 *  bitmap_weight_from(src, start, end)         Hamming Weight starting from @start
 *  bitmap_set(dst, pos, nbits)                 Set specified bit area
 *  bitmap_clear(dst, pos, nbits)               Clear specified bit area
 *  bitmap_find_next_zero_area(buf, len, pos, n, mask)  Find bit free area
 *  bitmap_find_next_zero_area_off(buf, len, pos, n, mask, mask_off)  as above
 *  bitmap_shift_right(dst, src, n, nbits)      *dst = *src >> n
 *  bitmap_shift_left(dst, src, n, nbits)       *dst = *src << n
 *  bitmap_cut(dst, src, first, n, nbits)       Cut n bits from first, copy rest
 *  bitmap_replace(dst, old, new, mask, nbits)  *dst = (*old & ~(*mask)) | (*new & *mask)
 *  bitmap_scatter(dst, src, mask, nbits)	*dst = map(dense, sparse)(src)
 *  bitmap_gather(dst, src, mask, nbits)	*dst = map(sparse, dense)(src)
 *  bitmap_remap(dst, src, old, new, nbits)     *dst = map(old, new)(src)
 *  bitmap_bitremap(oldbit, old, new, nbits)    newbit = map(old, new)(oldbit)
 *  bitmap_onto(dst, orig, relmap, nbits)       *dst = orig relative to relmap
 *  bitmap_fold(dst, orig, sz, nbits)           dst bits = orig bits mod sz
 *  bitmap_parse(buf, buflen, dst, nbits)       Parse bitmap dst from kernel buf
 *  bitmap_parse_user(ubuf, ulen, dst, nbits)   Parse bitmap dst from user buf
 *  bitmap_parselist(buf, dst, nbits)           Parse bitmap dst from kernel buf
 *  bitmap_parselist_user(buf, dst, nbits)      Parse bitmap dst from user buf
 *  bitmap_find_free_region(bitmap, bits, order)  Find and allocate bit region
 *  bitmap_release_region(bitmap, pos, order)   Free specified bit region
 *  bitmap_allocate_region(bitmap, pos, order)  Allocate specified bit region
 *  bitmap_from_arr32(dst, buf, nbits)          Copy nbits from u32[] buf to dst
 *  bitmap_from_arr64(dst, buf, nbits)          Copy nbits from u64[] buf to dst
 *  bitmap_to_arr32(buf, src, nbits)            Copy nbits from buf to u32[] dst
 *  bitmap_to_arr64(buf, src, nbits)            Copy nbits from buf to u64[] dst
 *  bitmap_get_value8(map, start)               Get 8bit value from map at start
 *  bitmap_set_value8(map, value, start)        Set 8bit value to map at start
 *  bitmap_read(map, start, nbits)              Read an nbits-sized value from
 *                                              map at start
 *  bitmap_write(map, value, start, nbits)      Write an nbits-sized value to

Annotation

Implementation Notes