diff options
Diffstat (limited to 'include/linux/bitmap.h')
| -rw-r--r-- | include/linux/bitmap.h | 171 |
1 files changed, 106 insertions, 65 deletions
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 19748a5b0e77..5f11fbdc27f8 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -22,65 +22,83 @@ * 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: * * Note that nbits should be always a compile time evaluable constant. * Otherwise many inlines will generate horrible code. * - * 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_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) as above - * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n - * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n - * 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_u32array(dst, nbits, buf, nwords) *dst = *buf (nwords 32b words) - * bitmap_to_u32array(buf, nwords, src, nbits) *buf = *dst (nwords 32b words) + * :: + * + * 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_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) as above + * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n + * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n + * 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_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst + * + * 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. */ -/* - * Also the following operations in asm/bitops.h apply to bitmaps. +/** + * 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) * - * 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 */ -/* +/** + * 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. @@ -165,14 +183,7 @@ extern void bitmap_fold(unsigned long *dst, const unsigned long *orig, extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order); extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order); extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order); -extern unsigned int bitmap_from_u32array(unsigned long *bitmap, - unsigned int nbits, - const u32 *buf, - unsigned int nwords); -extern unsigned int bitmap_to_u32array(u32 *buf, - unsigned int nwords, - const unsigned long *bitmap, - unsigned int nbits); + #ifdef __BIG_ENDIAN extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits); #else @@ -200,12 +211,12 @@ static inline void bitmap_zero(unsigned long *dst, unsigned int nbits) static inline void bitmap_fill(unsigned long *dst, unsigned int nbits) { - unsigned int nlongs = BITS_TO_LONGS(nbits); - if (!small_const_nbits(nbits)) { - unsigned int len = (nlongs - 1) * sizeof(unsigned long); - memset(dst, 0xff, len); + if (small_const_nbits(nbits)) + *dst = ~0UL; + else { + unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); + memset(dst, 0xff, len); } - dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits); } static inline void bitmap_copy(unsigned long *dst, const unsigned long *src, @@ -219,6 +230,35 @@ static inline void bitmap_copy(unsigned long *dst, const unsigned long *src, } } +/* + * 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, and + * therefore conversion is not needed when copying data from/to arrays of u32. + */ +#if BITS_PER_LONG == 64 +extern void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, + unsigned int nbits); +extern 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 + static inline int bitmap_and(unsigned long *dst, const unsigned long *src1, const unsigned long *src2, unsigned int nbits) { @@ -361,8 +401,9 @@ static inline int bitmap_parse(const char *buf, unsigned int buflen, return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits); } -/* +/** * 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. @@ -393,14 +434,14 @@ static inline int bitmap_parse(const char *buf, unsigned int buflen, ((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)[*] + * 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, + * 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) |