1 /* 2 * Bitmap Module 3 * 4 * Copyright (C) 2010 Corentin Chary <corentin.chary@gmail.com> 5 * 6 * Mostly inspired by (stolen from) linux/bitmap.h and linux/bitops.h 7 * 8 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later. 9 * See the COPYING.LIB file in the top-level directory. 10 */ 11 12 #ifndef BITMAP_H 13 #define BITMAP_H 14 15 16 #include "qemu/bitops.h" 17 18 /* 19 * The available bitmap operations and their rough meaning in the 20 * case that the bitmap is a single unsigned long are thus: 21 * 22 * Note that nbits should be always a compile time evaluable constant. 23 * Otherwise many inlines will generate horrible code. 24 * 25 * bitmap_zero(dst, nbits) *dst = 0UL 26 * bitmap_fill(dst, nbits) *dst = ~0UL 27 * bitmap_copy(dst, src, nbits) *dst = *src 28 * bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2 29 * bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2 30 * bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2 31 * bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 & ~(*src2) 32 * bitmap_complement(dst, src, nbits) *dst = ~(*src) 33 * bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal? 34 * bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap? 35 * bitmap_empty(src, nbits) Are all bits zero in *src? 36 * bitmap_full(src, nbits) Are all bits set in *src? 37 * bitmap_set(dst, pos, nbits) Set specified bit area 38 * bitmap_set_atomic(dst, pos, nbits) Set specified bit area with atomic ops 39 * bitmap_clear(dst, pos, nbits) Clear specified bit area 40 * bitmap_test_and_clear_atomic(dst, pos, nbits) Test and clear area 41 * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area 42 * bitmap_to_le(dst, src, nbits) Convert bitmap to little endian 43 * bitmap_from_le(dst, src, nbits) Convert bitmap from little endian 44 */ 45 46 /* 47 * Also the following operations apply to bitmaps. 48 * 49 * set_bit(bit, addr) *addr |= bit 50 * clear_bit(bit, addr) *addr &= ~bit 51 * change_bit(bit, addr) *addr ^= bit 52 * test_bit(bit, addr) Is bit set in *addr? 53 * test_and_set_bit(bit, addr) Set bit and return old value 54 * test_and_clear_bit(bit, addr) Clear bit and return old value 55 * test_and_change_bit(bit, addr) Change bit and return old value 56 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr 57 * find_first_bit(addr, nbits) Position first set bit in *addr 58 * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit 59 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit 60 */ 61 62 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) 63 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) 64 65 #define DECLARE_BITMAP(name,bits) \ 66 unsigned long name[BITS_TO_LONGS(bits)] 67 68 #define small_nbits(nbits) \ 69 ((nbits) <= BITS_PER_LONG) 70 71 int slow_bitmap_empty(const unsigned long *bitmap, long bits); 72 int slow_bitmap_full(const unsigned long *bitmap, long bits); 73 int slow_bitmap_equal(const unsigned long *bitmap1, 74 const unsigned long *bitmap2, long bits); 75 void slow_bitmap_complement(unsigned long *dst, const unsigned long *src, 76 long bits); 77 int slow_bitmap_and(unsigned long *dst, const unsigned long *bitmap1, 78 const unsigned long *bitmap2, long bits); 79 void slow_bitmap_or(unsigned long *dst, const unsigned long *bitmap1, 80 const unsigned long *bitmap2, long bits); 81 void slow_bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, 82 const unsigned long *bitmap2, long bits); 83 int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, 84 const unsigned long *bitmap2, long bits); 85 int slow_bitmap_intersects(const unsigned long *bitmap1, 86 const unsigned long *bitmap2, long bits); 87 long slow_bitmap_count_one(const unsigned long *bitmap, long nbits); 88 89 static inline unsigned long *bitmap_try_new(long nbits) 90 { 91 long len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 92 return g_try_malloc0(len); 93 } 94 95 static inline unsigned long *bitmap_new(long nbits) 96 { 97 unsigned long *ptr = bitmap_try_new(nbits); 98 if (ptr == NULL) { 99 abort(); 100 } 101 return ptr; 102 } 103 104 static inline void bitmap_zero(unsigned long *dst, long nbits) 105 { 106 if (small_nbits(nbits)) { 107 *dst = 0UL; 108 } else { 109 long len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 110 memset(dst, 0, len); 111 } 112 } 113 114 static inline void bitmap_fill(unsigned long *dst, long nbits) 115 { 116 size_t nlongs = BITS_TO_LONGS(nbits); 117 if (!small_nbits(nbits)) { 118 long len = (nlongs - 1) * sizeof(unsigned long); 119 memset(dst, 0xff, len); 120 } 121 dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits); 122 } 123 124 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src, 125 long nbits) 126 { 127 if (small_nbits(nbits)) { 128 *dst = *src; 129 } else { 130 long len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 131 memcpy(dst, src, len); 132 } 133 } 134 135 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1, 136 const unsigned long *src2, long nbits) 137 { 138 if (small_nbits(nbits)) { 139 return (*dst = *src1 & *src2) != 0; 140 } 141 return slow_bitmap_and(dst, src1, src2, nbits); 142 } 143 144 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1, 145 const unsigned long *src2, long nbits) 146 { 147 if (small_nbits(nbits)) { 148 *dst = *src1 | *src2; 149 } else { 150 slow_bitmap_or(dst, src1, src2, nbits); 151 } 152 } 153 154 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1, 155 const unsigned long *src2, long nbits) 156 { 157 if (small_nbits(nbits)) { 158 *dst = *src1 ^ *src2; 159 } else { 160 slow_bitmap_xor(dst, src1, src2, nbits); 161 } 162 } 163 164 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1, 165 const unsigned long *src2, long nbits) 166 { 167 if (small_nbits(nbits)) { 168 return (*dst = *src1 & ~(*src2)) != 0; 169 } 170 return slow_bitmap_andnot(dst, src1, src2, nbits); 171 } 172 173 static inline void bitmap_complement(unsigned long *dst, 174 const unsigned long *src, 175 long nbits) 176 { 177 if (small_nbits(nbits)) { 178 *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits); 179 } else { 180 slow_bitmap_complement(dst, src, nbits); 181 } 182 } 183 184 static inline int bitmap_equal(const unsigned long *src1, 185 const unsigned long *src2, long nbits) 186 { 187 if (small_nbits(nbits)) { 188 return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits)); 189 } else { 190 return slow_bitmap_equal(src1, src2, nbits); 191 } 192 } 193 194 static inline int bitmap_empty(const unsigned long *src, long nbits) 195 { 196 if (small_nbits(nbits)) { 197 return ! (*src & BITMAP_LAST_WORD_MASK(nbits)); 198 } else { 199 return slow_bitmap_empty(src, nbits); 200 } 201 } 202 203 static inline int bitmap_full(const unsigned long *src, long nbits) 204 { 205 if (small_nbits(nbits)) { 206 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits)); 207 } else { 208 return slow_bitmap_full(src, nbits); 209 } 210 } 211 212 static inline int bitmap_intersects(const unsigned long *src1, 213 const unsigned long *src2, long nbits) 214 { 215 if (small_nbits(nbits)) { 216 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; 217 } else { 218 return slow_bitmap_intersects(src1, src2, nbits); 219 } 220 } 221 222 static inline long bitmap_count_one(const unsigned long *bitmap, long nbits) 223 { 224 if (unlikely(!nbits)) { 225 return 0; 226 } 227 228 if (small_nbits(nbits)) { 229 return ctpopl(*bitmap & BITMAP_LAST_WORD_MASK(nbits)); 230 } else { 231 return slow_bitmap_count_one(bitmap, nbits); 232 } 233 } 234 235 static inline long bitmap_count_one_with_offset(const unsigned long *bitmap, 236 long offset, long nbits) 237 { 238 long aligned_offset = QEMU_ALIGN_DOWN(offset, BITS_PER_LONG); 239 long redundant_bits = offset - aligned_offset; 240 long bits_to_count = nbits + redundant_bits; 241 const unsigned long *bitmap_start = bitmap + 242 aligned_offset / BITS_PER_LONG; 243 244 return bitmap_count_one(bitmap_start, bits_to_count) - 245 bitmap_count_one(bitmap_start, redundant_bits); 246 } 247 248 void bitmap_set(unsigned long *map, long i, long len); 249 void bitmap_set_atomic(unsigned long *map, long i, long len); 250 void bitmap_clear(unsigned long *map, long start, long nr); 251 bool bitmap_test_and_clear_atomic(unsigned long *map, long start, long nr); 252 void bitmap_copy_and_clear_atomic(unsigned long *dst, unsigned long *src, 253 long nr); 254 unsigned long bitmap_find_next_zero_area(unsigned long *map, 255 unsigned long size, 256 unsigned long start, 257 unsigned long nr, 258 unsigned long align_mask); 259 260 static inline unsigned long *bitmap_zero_extend(unsigned long *old, 261 long old_nbits, long new_nbits) 262 { 263 long new_len = BITS_TO_LONGS(new_nbits) * sizeof(unsigned long); 264 unsigned long *new = g_realloc(old, new_len); 265 bitmap_clear(new, old_nbits, new_nbits - old_nbits); 266 return new; 267 } 268 269 void bitmap_to_le(unsigned long *dst, const unsigned long *src, 270 long nbits); 271 void bitmap_from_le(unsigned long *dst, const unsigned long *src, 272 long nbits); 273 274 #endif /* BITMAP_H */ 275