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Diffstat (limited to 'include/linux/bitmap.h')
| -rw-r--r-- | include/linux/bitmap.h | 604 |
1 files changed, 604 insertions, 0 deletions
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h new file mode 100644 index 000000000..03644237e --- /dev/null +++ b/include/linux/bitmap.h @@ -0,0 +1,604 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __LINUX_BITMAP_H +#define __LINUX_BITMAP_H + +#ifndef __ASSEMBLY__ + +#include <linux/align.h> +#include <linux/bitops.h> +#include <linux/find.h> +#include <linux/limits.h> +#include <linux/string.h> +#include <linux/types.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 include/asm-<arch>/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_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_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_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 + * + * Note, bitmap_zero() and bitmap_fill() operate over the region of + * unsigned longs, that is, bits behind bitmap till the unsigned long + * boundary will be zeroed or filled as well. Consider to use + * bitmap_clear() or bitmap_set() to make explicit zeroing or filling + * respectively. + */ + +/** + * DOC: bitmap bitops + * + * Also the following operations in asm/bitops.h apply to bitmaps.:: + * + * set_bit(bit, addr) *addr |= bit + * clear_bit(bit, addr) *addr &= ~bit + * change_bit(bit, addr) *addr ^= bit + * test_bit(bit, addr) Is bit set in *addr? + * test_and_set_bit(bit, addr) Set bit and return old value + * test_and_clear_bit(bit, addr) Clear bit and return old value + * test_and_change_bit(bit, addr) Change bit and return old value + * find_first_zero_bit(addr, nbits) Position first zero bit in *addr + * find_first_bit(addr, nbits) Position first set bit in *addr + * find_next_zero_bit(addr, nbits, bit) + * Position next zero bit in *addr >= bit + * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit + * find_next_and_bit(addr1, addr2, nbits, bit) + * Same as find_next_bit, but in + * (*addr1 & *addr2) + * + */ + +/** + * DOC: declare bitmap + * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used + * to declare an array named 'name' of just enough unsigned longs to + * contain all bit positions from 0 to 'bits' - 1. + */ + +/* + * Allocation and deallocation of bitmap. + * Provided in lib/bitmap.c to avoid circular dependency. + */ +unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags); +unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags); +unsigned long *bitmap_alloc_node(unsigned int nbits, gfp_t flags, int node); +unsigned long *bitmap_zalloc_node(unsigned int nbits, gfp_t flags, int node); +void bitmap_free(const unsigned long *bitmap); + +/* Managed variants of the above. */ +unsigned long *devm_bitmap_alloc(struct device *dev, + unsigned int nbits, gfp_t flags); +unsigned long *devm_bitmap_zalloc(struct device *dev, + unsigned int nbits, gfp_t flags); + +/* + * lib/bitmap.c provides these functions: + */ + +bool __bitmap_equal(const unsigned long *bitmap1, + const unsigned long *bitmap2, unsigned int nbits); +bool __pure __bitmap_or_equal(const unsigned long *src1, + const unsigned long *src2, + const unsigned long *src3, + unsigned int nbits); +void __bitmap_complement(unsigned long *dst, const unsigned long *src, + unsigned int nbits); +void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, + unsigned int shift, unsigned int nbits); +void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, + unsigned int shift, unsigned int nbits); +void bitmap_cut(unsigned long *dst, const unsigned long *src, + unsigned int first, unsigned int cut, unsigned int nbits); +bool __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, + const unsigned long *bitmap2, unsigned int nbits); +void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, + const unsigned long *bitmap2, unsigned int nbits); +void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, + const unsigned long *bitmap2, unsigned int nbits); +bool __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, + const unsigned long *bitmap2, unsigned int nbits); +void __bitmap_replace(unsigned long *dst, + const unsigned long *old, const unsigned long *new, + const unsigned long *mask, unsigned int nbits); +bool __bitmap_intersects(const unsigned long *bitmap1, + const unsigned long *bitmap2, unsigned int nbits); +bool __bitmap_subset(const unsigned long *bitmap1, + const unsigned long *bitmap2, unsigned int nbits); +unsigned int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits); +unsigned int __bitmap_weight_and(const unsigned long *bitmap1, + const unsigned long *bitmap2, unsigned int nbits); +void __bitmap_set(unsigned long *map, unsigned int start, int len); +void __bitmap_clear(unsigned long *map, unsigned int start, int len); + +unsigned long bitmap_find_next_zero_area_off(unsigned long *map, + unsigned long size, + unsigned long start, + unsigned int nr, + unsigned long align_mask, + unsigned long align_offset); + +/** + * bitmap_find_next_zero_area - find a contiguous aligned zero area + * @map: The address to base the search on + * @size: The bitmap size in bits + * @start: The bitnumber to start searching at + * @nr: The number of zeroed bits we're looking for + * @align_mask: Alignment mask for zero area + * + * The @align_mask should be one less than a power of 2; the effect is that + * the bit offset of all zero areas this function finds is multiples of that + * power of 2. A @align_mask of 0 means no alignment is required. + */ +static inline unsigned long +bitmap_find_next_zero_area(unsigned long *map, + unsigned long size, + unsigned long start, + unsigned int nr, + unsigned long align_mask) +{ + return bitmap_find_next_zero_area_off(map, size, start, nr, + align_mask, 0); +} + +int bitmap_parse(const char *buf, unsigned int buflen, + unsigned long *dst, int nbits); +int bitmap_parse_user(const char __user *ubuf, unsigned int ulen, + unsigned long *dst, int nbits); +int bitmap_parselist(const char *buf, unsigned long *maskp, + int nmaskbits); +int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen, + unsigned long *dst, int nbits); +void bitmap_remap(unsigned long *dst, const unsigned long *src, + const unsigned long *old, const unsigned long *new, unsigned int nbits); +int bitmap_bitremap(int oldbit, + const unsigned long *old, const unsigned long *new, int bits); +void bitmap_onto(unsigned long *dst, const unsigned long *orig, + const unsigned long *relmap, unsigned int bits); +void bitmap_fold(unsigned long *dst, const unsigned long *orig, + unsigned int sz, unsigned int nbits); +int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order); +void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order); +int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order); + +#ifdef __BIG_ENDIAN +void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits); +#else +#define bitmap_copy_le bitmap_copy +#endif +int bitmap_print_to_pagebuf(bool list, char *buf, + const unsigned long *maskp, int nmaskbits); + +extern int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp, + int nmaskbits, loff_t off, size_t count); + +extern int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp, + int nmaskbits, loff_t off, size_t count); + +#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) +#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) + +static inline void bitmap_zero(unsigned long *dst, unsigned int nbits) +{ + unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); + + if (small_const_nbits(nbits)) + *dst = 0; + else + memset(dst, 0, len); +} + +static inline void bitmap_fill(unsigned long *dst, unsigned int nbits) +{ + unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); + + if (small_const_nbits(nbits)) + *dst = ~0UL; + else + memset(dst, 0xff, len); +} + +static inline void bitmap_copy(unsigned long *dst, const unsigned long *src, + unsigned int nbits) +{ + unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); + + if (small_const_nbits(nbits)) + *dst = *src; + else + memcpy(dst, src, len); +} + +/* + * Copy bitmap and clear tail bits in last word. + */ +static inline void bitmap_copy_clear_tail(unsigned long *dst, + const unsigned long *src, unsigned int nbits) +{ + bitmap_copy(dst, src, nbits); + if (nbits % BITS_PER_LONG) + dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits); +} + +/* + * On 32-bit systems bitmaps are represented as u32 arrays internally. On LE64 + * machines the order of hi and lo parts of numbers match the bitmap structure. + * In both cases conversion is not needed when copying data from/to arrays of + * u32. But in LE64 case, typecast in bitmap_copy_clear_tail() may lead + * to out-of-bound access. To avoid that, both LE and BE variants of 64-bit + * architectures are not using bitmap_copy_clear_tail(). + */ +#if BITS_PER_LONG == 64 +void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, + unsigned int nbits); +void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, + unsigned int nbits); +#else +#define bitmap_from_arr32(bitmap, buf, nbits) \ + bitmap_copy_clear_tail((unsigned long *) (bitmap), \ + (const unsigned long *) (buf), (nbits)) +#define bitmap_to_arr32(buf, bitmap, nbits) \ + bitmap_copy_clear_tail((unsigned long *) (buf), \ + (const unsigned long *) (bitmap), (nbits)) +#endif + +/* + * On 64-bit systems bitmaps are represented as u64 arrays internally. So, + * the conversion is not needed when copying data from/to arrays of u64. + */ +#if BITS_PER_LONG == 32 +void bitmap_from_arr64(unsigned long *bitmap, const u64 *buf, unsigned int nbits); +void bitmap_to_arr64(u64 *buf, const unsigned long *bitmap, unsigned int nbits); +#else +#define bitmap_from_arr64(bitmap, buf, nbits) \ + bitmap_copy_clear_tail((unsigned long *)(bitmap), (const unsigned long *)(buf), (nbits)) +#define bitmap_to_arr64(buf, bitmap, nbits) \ + bitmap_copy_clear_tail((unsigned long *)(buf), (const unsigned long *)(bitmap), (nbits)) +#endif + +static inline bool bitmap_and(unsigned long *dst, const unsigned long *src1, + const unsigned long *src2, unsigned int nbits) +{ + if (small_const_nbits(nbits)) + return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0; + return __bitmap_and(dst, src1, src2, nbits); +} + +static inline void bitmap_or(unsigned long *dst, const unsigned long *src1, + const unsigned long *src2, unsigned int nbits) +{ + if (small_const_nbits(nbits)) + *dst = *src1 | *src2; + else + __bitmap_or(dst, src1, src2, nbits); +} + +static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1, + const unsigned long *src2, unsigned int nbits) +{ + if (small_const_nbits(nbits)) + *dst = *src1 ^ *src2; + else + __bitmap_xor(dst, src1, src2, nbits); +} + +static inline bool bitmap_andnot(unsigned long *dst, const unsigned long *src1, + const unsigned long *src2, unsigned int nbits) +{ + if (small_const_nbits(nbits)) + return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; + return __bitmap_andnot(dst, src1, src2, nbits); +} + +static inline void bitmap_complement(unsigned long *dst, const unsigned long *src, + unsigned int nbits) +{ + if (small_const_nbits(nbits)) + *dst = ~(*src); + else + __bitmap_complement(dst, src, nbits); +} + +#ifdef __LITTLE_ENDIAN +#define BITMAP_MEM_ALIGNMENT 8 +#else +#define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long)) +#endif +#define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1) + +static inline bool bitmap_equal(const unsigned long *src1, + const unsigned long *src2, unsigned int nbits) +{ + if (small_const_nbits(nbits)) + return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits)); + if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) && + IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT)) + return !memcmp(src1, src2, nbits / 8); + return __bitmap_equal(src1, src2, nbits); +} + +/** + * bitmap_or_equal - Check whether the or of two bitmaps is equal to a third + * @src1: Pointer to bitmap 1 + * @src2: Pointer to bitmap 2 will be or'ed with bitmap 1 + * @src3: Pointer to bitmap 3. Compare to the result of *@src1 | *@src2 + * @nbits: number of bits in each of these bitmaps + * + * Returns: True if (*@src1 | *@src2) == *@src3, false otherwise + */ +static inline bool bitmap_or_equal(const unsigned long *src1, + const unsigned long *src2, + const unsigned long *src3, + unsigned int nbits) +{ + if (!small_const_nbits(nbits)) + return __bitmap_or_equal(src1, src2, src3, nbits); + + return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits)); +} + +static inline bool bitmap_intersects(const unsigned long *src1, + const unsigned long *src2, + unsigned int nbits) +{ + if (small_const_nbits(nbits)) + return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; + else + return __bitmap_intersects(src1, src2, nbits); +} + +static inline bool bitmap_subset(const unsigned long *src1, + const unsigned long *src2, unsigned int nbits) +{ + if (small_const_nbits(nbits)) + return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits)); + else + return __bitmap_subset(src1, src2, nbits); +} + +static inline bool bitmap_empty(const unsigned long *src, unsigned nbits) +{ + if (small_const_nbits(nbits)) + return ! (*src & BITMAP_LAST_WORD_MASK(nbits)); + + return find_first_bit(src, nbits) == nbits; +} + +static inline bool bitmap_full(const unsigned long *src, unsigned int nbits) +{ + if (small_const_nbits(nbits)) + return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits)); + + return find_first_zero_bit(src, nbits) == nbits; +} + +static __always_inline +unsigned int bitmap_weight(const unsigned long *src, unsigned int nbits) +{ + if (small_const_nbits(nbits)) + return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits)); + return __bitmap_weight(src, nbits); +} + +static __always_inline +unsigned long bitmap_weight_and(const unsigned long *src1, + const unsigned long *src2, unsigned int nbits) +{ + if (small_const_nbits(nbits)) + return hweight_long(*src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)); + return __bitmap_weight_and(src1, src2, nbits); +} + +static __always_inline void bitmap_set(unsigned long *map, unsigned int start, + unsigned int nbits) +{ + if (__builtin_constant_p(nbits) && nbits == 1) + __set_bit(start, map); + else if (small_const_nbits(start + nbits)) + *map |= GENMASK(start + nbits - 1, start); + else if (__builtin_constant_p(start & BITMAP_MEM_MASK) && + IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) && + __builtin_constant_p(nbits & BITMAP_MEM_MASK) && + IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT)) + memset((char *)map + start / 8, 0xff, nbits / 8); + else + __bitmap_set(map, start, nbits); +} + +static __always_inline void bitmap_clear(unsigned long *map, unsigned int start, + unsigned int nbits) +{ + if (__builtin_constant_p(nbits) && nbits == 1) + __clear_bit(start, map); + else if (small_const_nbits(start + nbits)) + *map &= ~GENMASK(start + nbits - 1, start); + else if (__builtin_constant_p(start & BITMAP_MEM_MASK) && + IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) && + __builtin_constant_p(nbits & BITMAP_MEM_MASK) && + IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT)) + memset((char *)map + start / 8, 0, nbits / 8); + else + __bitmap_clear(map, start, nbits); +} + +static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src, + unsigned int shift, unsigned int nbits) +{ + if (small_const_nbits(nbits)) + *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift; + else + __bitmap_shift_right(dst, src, shift, nbits); +} + +static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src, + unsigned int shift, unsigned int nbits) +{ + if (small_const_nbits(nbits)) + *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits); + else + __bitmap_shift_left(dst, src, shift, nbits); +} + +static inline void bitmap_replace(unsigned long *dst, + const unsigned long *old, + const unsigned long *new, + const unsigned long *mask, + unsigned int nbits) +{ + if (small_const_nbits(nbits)) + *dst = (*old & ~(*mask)) | (*new & *mask); + else + __bitmap_replace(dst, old, new, mask, nbits); +} + +static inline void bitmap_next_set_region(unsigned long *bitmap, + unsigned int *rs, unsigned int *re, + unsigned int end) +{ + *rs = find_next_bit(bitmap, end, *rs); + *re = find_next_zero_bit(bitmap, end, *rs + 1); +} + +/** + * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap. + * @n: u64 value + * + * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit + * integers in 32-bit environment, and 64-bit integers in 64-bit one. + * + * There are four combinations of endianness and length of the word in linux + * ABIs: LE64, BE64, LE32 and BE32. + * + * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in + * bitmaps and therefore don't require any special handling. + * + * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory + * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the + * other hand is represented as an array of 32-bit words and the position of + * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that + * word. For example, bit #42 is located at 10th position of 2nd word. + * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit + * values in memory as it usually does. But for BE we need to swap hi and lo + * words manually. + * + * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and + * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps + * hi and lo words, as is expected by bitmap. + */ +#if __BITS_PER_LONG == 64 +#define BITMAP_FROM_U64(n) (n) +#else +#define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \ + ((unsigned long) ((u64)(n) >> 32)) +#endif + +/** + * bitmap_from_u64 - Check and swap words within u64. + * @mask: source bitmap + * @dst: destination bitmap + * + * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]`` + * to read u64 mask, we will get the wrong word. + * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits, + * but we expect the lower 32-bits of u64. + */ +static inline void bitmap_from_u64(unsigned long *dst, u64 mask) +{ + bitmap_from_arr64(dst, &mask, 64); +} + +/** + * bitmap_get_value8 - get an 8-bit value within a memory region + * @map: address to the bitmap memory region + * @start: bit offset of the 8-bit value; must be a multiple of 8 + * + * Returns the 8-bit value located at the @start bit offset within the @src + * memory region. + */ +static inline unsigned long bitmap_get_value8(const unsigned long *map, + unsigned long start) +{ + const size_t index = BIT_WORD(start); + const unsigned long offset = start % BITS_PER_LONG; + + return (map[index] >> offset) & 0xFF; +} + +/** + * bitmap_set_value8 - set an 8-bit value within a memory region + * @map: address to the bitmap memory region + * @value: the 8-bit value; values wider than 8 bits may clobber bitmap + * @start: bit offset of the 8-bit value; must be a multiple of 8 + */ +static inline void bitmap_set_value8(unsigned long *map, unsigned long value, + unsigned long start) +{ + const size_t index = BIT_WORD(start); + const unsigned long offset = start % BITS_PER_LONG; + + map[index] &= ~(0xFFUL << offset); + map[index] |= value << offset; +} + +#endif /* __ASSEMBLY__ */ + +#endif /* __LINUX_BITMAP_H */ |