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 * bitmap_copy_with_src_offset(dst, src, offset, nbits) 45 * *dst = *src (with an offset into src) 46 * bitmap_copy_with_dst_offset(dst, src, offset, nbits) 47 * *dst = *src (with an offset into dst) 48 */ 49 50 /* 51 * Also the following operations apply to bitmaps. 52 * 53 * set_bit(bit, addr) *addr |= bit 54 * clear_bit(bit, addr) *addr &= ~bit 55 * change_bit(bit, addr) *addr ^= bit 56 * test_bit(bit, addr) Is bit set in *addr? 57 * test_and_set_bit(bit, addr) Set bit and return old value 58 * test_and_clear_bit(bit, addr) Clear bit and return old value 59 * test_and_change_bit(bit, addr) Change bit and return old value 60 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr 61 * find_first_bit(addr, nbits) Position first set bit in *addr 62 * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit 63 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit 64 */ 65 66 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) 67 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) 68 69 #define DECLARE_BITMAP(name,bits) \ 70 unsigned long name[BITS_TO_LONGS(bits)] 71 72 #define small_nbits(nbits) \ 73 ((nbits) <= BITS_PER_LONG) 74 75 int slow_bitmap_empty(const unsigned long *bitmap, long bits); 76 int slow_bitmap_full(const unsigned long *bitmap, long bits); 77 int slow_bitmap_equal(const unsigned long *bitmap1, 78 const unsigned long *bitmap2, long bits); 79 void slow_bitmap_complement(unsigned long *dst, const unsigned long *src, 80 long bits); 81 int slow_bitmap_and(unsigned long *dst, const unsigned long *bitmap1, 82 const unsigned long *bitmap2, long bits); 83 void slow_bitmap_or(unsigned long *dst, const unsigned long *bitmap1, 84 const unsigned long *bitmap2, long bits); 85 void slow_bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, 86 const unsigned long *bitmap2, long bits); 87 int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, 88 const unsigned long *bitmap2, long bits); 89 int slow_bitmap_intersects(const unsigned long *bitmap1, 90 const unsigned long *bitmap2, long bits); 91 long slow_bitmap_count_one(const unsigned long *bitmap, long nbits); 92 93 static inline unsigned long *bitmap_try_new(long nbits) 94 { 95 long len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 96 return g_try_malloc0(len); 97 } 98 99 static inline unsigned long *bitmap_new(long nbits) 100 { 101 unsigned long *ptr = bitmap_try_new(nbits); 102 if (ptr == NULL) { 103 abort(); 104 } 105 return ptr; 106 } 107 108 static inline void bitmap_zero(unsigned long *dst, long nbits) 109 { 110 if (small_nbits(nbits)) { 111 *dst = 0UL; 112 } else { 113 long len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 114 memset(dst, 0, len); 115 } 116 } 117 118 static inline void bitmap_fill(unsigned long *dst, long nbits) 119 { 120 size_t nlongs = BITS_TO_LONGS(nbits); 121 if (!small_nbits(nbits)) { 122 long len = (nlongs - 1) * sizeof(unsigned long); 123 memset(dst, 0xff, len); 124 } 125 dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits); 126 } 127 128 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src, 129 long nbits) 130 { 131 if (small_nbits(nbits)) { 132 *dst = *src; 133 } else { 134 long len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 135 memcpy(dst, src, len); 136 } 137 } 138 139 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1, 140 const unsigned long *src2, long nbits) 141 { 142 if (small_nbits(nbits)) { 143 return (*dst = *src1 & *src2) != 0; 144 } 145 return slow_bitmap_and(dst, src1, src2, nbits); 146 } 147 148 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1, 149 const unsigned long *src2, long nbits) 150 { 151 if (small_nbits(nbits)) { 152 *dst = *src1 | *src2; 153 } else { 154 slow_bitmap_or(dst, src1, src2, nbits); 155 } 156 } 157 158 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1, 159 const unsigned long *src2, long nbits) 160 { 161 if (small_nbits(nbits)) { 162 *dst = *src1 ^ *src2; 163 } else { 164 slow_bitmap_xor(dst, src1, src2, nbits); 165 } 166 } 167 168 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1, 169 const unsigned long *src2, long nbits) 170 { 171 if (small_nbits(nbits)) { 172 return (*dst = *src1 & ~(*src2)) != 0; 173 } 174 return slow_bitmap_andnot(dst, src1, src2, nbits); 175 } 176 177 static inline void bitmap_complement(unsigned long *dst, 178 const unsigned long *src, 179 long nbits) 180 { 181 if (small_nbits(nbits)) { 182 *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits); 183 } else { 184 slow_bitmap_complement(dst, src, nbits); 185 } 186 } 187 188 static inline int bitmap_equal(const unsigned long *src1, 189 const unsigned long *src2, long nbits) 190 { 191 if (small_nbits(nbits)) { 192 return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits)); 193 } else { 194 return slow_bitmap_equal(src1, src2, nbits); 195 } 196 } 197 198 static inline int bitmap_empty(const unsigned long *src, long nbits) 199 { 200 if (small_nbits(nbits)) { 201 return ! (*src & BITMAP_LAST_WORD_MASK(nbits)); 202 } else { 203 return slow_bitmap_empty(src, nbits); 204 } 205 } 206 207 static inline int bitmap_full(const unsigned long *src, long nbits) 208 { 209 if (small_nbits(nbits)) { 210 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits)); 211 } else { 212 return slow_bitmap_full(src, nbits); 213 } 214 } 215 216 static inline int bitmap_intersects(const unsigned long *src1, 217 const unsigned long *src2, long nbits) 218 { 219 if (small_nbits(nbits)) { 220 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; 221 } else { 222 return slow_bitmap_intersects(src1, src2, nbits); 223 } 224 } 225 226 static inline long bitmap_count_one(const unsigned long *bitmap, long nbits) 227 { 228 if (unlikely(!nbits)) { 229 return 0; 230 } 231 232 if (small_nbits(nbits)) { 233 return ctpopl(*bitmap & BITMAP_LAST_WORD_MASK(nbits)); 234 } else { 235 return slow_bitmap_count_one(bitmap, nbits); 236 } 237 } 238 239 static inline long bitmap_count_one_with_offset(const unsigned long *bitmap, 240 long offset, long nbits) 241 { 242 long aligned_offset = QEMU_ALIGN_DOWN(offset, BITS_PER_LONG); 243 long redundant_bits = offset - aligned_offset; 244 long bits_to_count = nbits + redundant_bits; 245 const unsigned long *bitmap_start = bitmap + 246 aligned_offset / BITS_PER_LONG; 247 248 return bitmap_count_one(bitmap_start, bits_to_count) - 249 bitmap_count_one(bitmap_start, redundant_bits); 250 } 251 252 void bitmap_set(unsigned long *map, long i, long len); 253 void bitmap_set_atomic(unsigned long *map, long i, long len); 254 void bitmap_clear(unsigned long *map, long start, long nr); 255 bool bitmap_test_and_clear_atomic(unsigned long *map, long start, long nr); 256 bool bitmap_test_and_clear(unsigned long *map, long start, long nr); 257 void bitmap_copy_and_clear_atomic(unsigned long *dst, unsigned long *src, 258 long nr); 259 unsigned long bitmap_find_next_zero_area(unsigned long *map, 260 unsigned long size, 261 unsigned long start, 262 unsigned long nr, 263 unsigned long align_mask); 264 265 static inline unsigned long *bitmap_zero_extend(unsigned long *old, 266 long old_nbits, long new_nbits) 267 { 268 long new_len = BITS_TO_LONGS(new_nbits) * sizeof(unsigned long); 269 unsigned long *new = g_realloc(old, new_len); 270 bitmap_clear(new, old_nbits, new_nbits - old_nbits); 271 return new; 272 } 273 274 void bitmap_to_le(unsigned long *dst, const unsigned long *src, 275 long nbits); 276 void bitmap_from_le(unsigned long *dst, const unsigned long *src, 277 long nbits); 278 279 void bitmap_copy_with_src_offset(unsigned long *dst, const unsigned long *src, 280 unsigned long offset, unsigned long nbits); 281 void bitmap_copy_with_dst_offset(unsigned long *dst, const unsigned long *src, 282 unsigned long shift, unsigned long nbits); 283 284 #endif /* BITMAP_H */ 285