123 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * From lib/bitmap.c4 * Helper functions for bitmap.h.5 */6#include <linux/bitmap.h>7 8unsigned int __bitmap_weight(const unsigned long *bitmap, int bits)9{10 unsigned int k, w = 0, lim = bits/BITS_PER_LONG;11 12 for (k = 0; k < lim; k++)13 w += hweight_long(bitmap[k]);14 15 if (bits % BITS_PER_LONG)16 w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));17 18 return w;19}20 21void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,22 const unsigned long *bitmap2, int bits)23{24 int k;25 int nr = BITS_TO_LONGS(bits);26 27 for (k = 0; k < nr; k++)28 dst[k] = bitmap1[k] | bitmap2[k];29}30 31size_t bitmap_scnprintf(unsigned long *bitmap, unsigned int nbits,32 char *buf, size_t size)33{34 /* current bit is 'cur', most recently seen range is [rbot, rtop] */35 unsigned int cur, rbot, rtop;36 bool first = true;37 size_t ret = 0;38 39 rbot = cur = find_first_bit(bitmap, nbits);40 while (cur < nbits) {41 rtop = cur;42 cur = find_next_bit(bitmap, nbits, cur + 1);43 if (cur < nbits && cur <= rtop + 1)44 continue;45 46 if (!first)47 ret += scnprintf(buf + ret, size - ret, ",");48 49 first = false;50 51 ret += scnprintf(buf + ret, size - ret, "%d", rbot);52 if (rbot < rtop)53 ret += scnprintf(buf + ret, size - ret, "-%d", rtop);54 55 rbot = cur;56 }57 return ret;58}59 60bool __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,61 const unsigned long *bitmap2, unsigned int bits)62{63 unsigned int k;64 unsigned int lim = bits/BITS_PER_LONG;65 unsigned long result = 0;66 67 for (k = 0; k < lim; k++)68 result |= (dst[k] = bitmap1[k] & bitmap2[k]);69 if (bits % BITS_PER_LONG)70 result |= (dst[k] = bitmap1[k] & bitmap2[k] &71 BITMAP_LAST_WORD_MASK(bits));72 return result != 0;73}74 75bool __bitmap_equal(const unsigned long *bitmap1,76 const unsigned long *bitmap2, unsigned int bits)77{78 unsigned int k, lim = bits/BITS_PER_LONG;79 for (k = 0; k < lim; ++k)80 if (bitmap1[k] != bitmap2[k])81 return false;82 83 if (bits % BITS_PER_LONG)84 if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))85 return false;86 87 return true;88}89 90bool __bitmap_intersects(const unsigned long *bitmap1,91 const unsigned long *bitmap2, unsigned int bits)92{93 unsigned int k, lim = bits/BITS_PER_LONG;94 for (k = 0; k < lim; ++k)95 if (bitmap1[k] & bitmap2[k])96 return true;97 98 if (bits % BITS_PER_LONG)99 if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))100 return true;101 return false;102}103 104void __bitmap_clear(unsigned long *map, unsigned int start, int len)105{106 unsigned long *p = map + BIT_WORD(start);107 const unsigned int size = start + len;108 int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);109 unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);110 111 while (len - bits_to_clear >= 0) {112 *p &= ~mask_to_clear;113 len -= bits_to_clear;114 bits_to_clear = BITS_PER_LONG;115 mask_to_clear = ~0UL;116 p++;117 }118 if (len) {119 mask_to_clear &= BITMAP_LAST_WORD_MASK(size);120 *p &= ~mask_to_clear;121 }122}123