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