1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * From lib/bitmap.c 4 * Helper functions for bitmap.h. 5 */ 6 #include <linux/bitmap.h> 7 8 unsigned 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 21 void __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 31 size_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 60 bool __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 75 bool __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 90 bool __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 } 103 104 void __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