Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 1 | #ifndef _ASM_X86_BITOPS_H |
| 2 | #define _ASM_X86_BITOPS_H |
| 3 | |
| 4 | /* |
| 5 | * Copyright 1992, Linus Torvalds. |
| 6 | */ |
| 7 | |
| 8 | #ifndef _LINUX_BITOPS_H |
| 9 | #error only <linux/bitops.h> can be included directly |
| 10 | #endif |
| 11 | |
| 12 | #include <linux/compiler.h> |
| 13 | #include <asm/alternative.h> |
| 14 | |
| 15 | /* |
| 16 | * These have to be done with inline assembly: that way the bit-setting |
| 17 | * is guaranteed to be atomic. All bit operations return 0 if the bit |
| 18 | * was cleared before the operation and != 0 if it was not. |
| 19 | * |
| 20 | * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1). |
| 21 | */ |
| 22 | |
| 23 | #if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 1) |
| 24 | /* Technically wrong, but this avoids compilation errors on some gcc |
| 25 | versions. */ |
Linus Torvalds | 1a750e0 | 2008-06-18 21:03:26 -0700 | [diff] [blame^] | 26 | #define BITOP_ADDR(x) "=m" (*(volatile long *) (x)) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 27 | #else |
Linus Torvalds | 1a750e0 | 2008-06-18 21:03:26 -0700 | [diff] [blame^] | 28 | #define BITOP_ADDR(x) "+m" (*(volatile long *) (x)) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 29 | #endif |
| 30 | |
Linus Torvalds | 1a750e0 | 2008-06-18 21:03:26 -0700 | [diff] [blame^] | 31 | #define ADDR BITOP_ADDR(addr) |
| 32 | |
| 33 | /* |
| 34 | * We do the locked ops that don't return the old value as |
| 35 | * a mask operation on a byte. |
| 36 | */ |
| 37 | #define IS_IMMEDIATE(nr) \ |
| 38 | (__builtin_constant_p(nr)) |
| 39 | #define CONST_MASK_ADDR BITOP_ADDR(addr + (nr>>3)) |
| 40 | #define CONST_MASK (1 << (nr & 7)) |
| 41 | |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 42 | /** |
| 43 | * set_bit - Atomically set a bit in memory |
| 44 | * @nr: the bit to set |
| 45 | * @addr: the address to start counting from |
| 46 | * |
| 47 | * This function is atomic and may not be reordered. See __set_bit() |
| 48 | * if you do not require the atomic guarantees. |
| 49 | * |
| 50 | * Note: there are no guarantees that this function will not be reordered |
| 51 | * on non x86 architectures, so if you are writing portable code, |
| 52 | * make sure not to rely on its reordering guarantees. |
| 53 | * |
| 54 | * Note that @nr may be almost arbitrarily large; this function is not |
| 55 | * restricted to acting on a single-word quantity. |
| 56 | */ |
Linus Torvalds | 1a750e0 | 2008-06-18 21:03:26 -0700 | [diff] [blame^] | 57 | static inline void set_bit(unsigned int nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 58 | { |
Linus Torvalds | 1a750e0 | 2008-06-18 21:03:26 -0700 | [diff] [blame^] | 59 | if (IS_IMMEDIATE(nr)) |
| 60 | asm volatile(LOCK_PREFIX "orb %1,%0" : CONST_MASK_ADDR : "i" (CONST_MASK) : "memory"); |
| 61 | else |
| 62 | asm volatile(LOCK_PREFIX "bts %1,%0" : ADDR : "Ir" (nr) : "memory"); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 63 | } |
| 64 | |
Linus Torvalds | 1a750e0 | 2008-06-18 21:03:26 -0700 | [diff] [blame^] | 65 | |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 66 | /** |
| 67 | * __set_bit - Set a bit in memory |
| 68 | * @nr: the bit to set |
| 69 | * @addr: the address to start counting from |
| 70 | * |
| 71 | * Unlike set_bit(), this function is non-atomic and may be reordered. |
| 72 | * If it's called on the same region of memory simultaneously, the effect |
| 73 | * may be that only one operation succeeds. |
| 74 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 75 | static inline void __set_bit(int nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 76 | { |
Joe Perches | f19dcf4 | 2008-03-23 01:03:07 -0700 | [diff] [blame] | 77 | asm volatile("bts %1,%0" : ADDR : "Ir" (nr) : "memory"); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 78 | } |
| 79 | |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 80 | /** |
| 81 | * clear_bit - Clears a bit in memory |
| 82 | * @nr: Bit to clear |
| 83 | * @addr: Address to start counting from |
| 84 | * |
| 85 | * clear_bit() is atomic and may not be reordered. However, it does |
| 86 | * not contain a memory barrier, so if it is used for locking purposes, |
| 87 | * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit() |
| 88 | * in order to ensure changes are visible on other processors. |
| 89 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 90 | static inline void clear_bit(int nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 91 | { |
Linus Torvalds | 1a750e0 | 2008-06-18 21:03:26 -0700 | [diff] [blame^] | 92 | if (IS_IMMEDIATE(nr)) |
| 93 | asm volatile(LOCK_PREFIX "andb %1,%0" : CONST_MASK_ADDR : "i" (~CONST_MASK)); |
| 94 | else |
| 95 | asm volatile(LOCK_PREFIX "btr %1,%0" : ADDR : "Ir" (nr)); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 96 | } |
| 97 | |
| 98 | /* |
| 99 | * clear_bit_unlock - Clears a bit in memory |
| 100 | * @nr: Bit to clear |
| 101 | * @addr: Address to start counting from |
| 102 | * |
| 103 | * clear_bit() is atomic and implies release semantics before the memory |
| 104 | * operation. It can be used for an unlock. |
| 105 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 106 | static inline void clear_bit_unlock(unsigned nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 107 | { |
| 108 | barrier(); |
| 109 | clear_bit(nr, addr); |
| 110 | } |
| 111 | |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 112 | static inline void __clear_bit(int nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 113 | { |
Simon Holm Thøgersen | eb2b4e6 | 2008-05-05 15:45:28 +0200 | [diff] [blame] | 114 | asm volatile("btr %1,%0" : ADDR : "Ir" (nr)); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 115 | } |
| 116 | |
| 117 | /* |
| 118 | * __clear_bit_unlock - Clears a bit in memory |
| 119 | * @nr: Bit to clear |
| 120 | * @addr: Address to start counting from |
| 121 | * |
| 122 | * __clear_bit() is non-atomic and implies release semantics before the memory |
| 123 | * operation. It can be used for an unlock if no other CPUs can concurrently |
| 124 | * modify other bits in the word. |
| 125 | * |
| 126 | * No memory barrier is required here, because x86 cannot reorder stores past |
| 127 | * older loads. Same principle as spin_unlock. |
| 128 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 129 | static inline void __clear_bit_unlock(unsigned nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 130 | { |
| 131 | barrier(); |
| 132 | __clear_bit(nr, addr); |
| 133 | } |
| 134 | |
| 135 | #define smp_mb__before_clear_bit() barrier() |
| 136 | #define smp_mb__after_clear_bit() barrier() |
| 137 | |
| 138 | /** |
| 139 | * __change_bit - Toggle a bit in memory |
| 140 | * @nr: the bit to change |
| 141 | * @addr: the address to start counting from |
| 142 | * |
| 143 | * Unlike change_bit(), this function is non-atomic and may be reordered. |
| 144 | * If it's called on the same region of memory simultaneously, the effect |
| 145 | * may be that only one operation succeeds. |
| 146 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 147 | static inline void __change_bit(int nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 148 | { |
Simon Holm Thøgersen | eb2b4e6 | 2008-05-05 15:45:28 +0200 | [diff] [blame] | 149 | asm volatile("btc %1,%0" : ADDR : "Ir" (nr)); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 150 | } |
| 151 | |
| 152 | /** |
| 153 | * change_bit - Toggle a bit in memory |
| 154 | * @nr: Bit to change |
| 155 | * @addr: Address to start counting from |
| 156 | * |
| 157 | * change_bit() is atomic and may not be reordered. |
| 158 | * Note that @nr may be almost arbitrarily large; this function is not |
| 159 | * restricted to acting on a single-word quantity. |
| 160 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 161 | static inline void change_bit(int nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 162 | { |
Simon Holm Thøgersen | eb2b4e6 | 2008-05-05 15:45:28 +0200 | [diff] [blame] | 163 | asm volatile(LOCK_PREFIX "btc %1,%0" : ADDR : "Ir" (nr)); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 164 | } |
| 165 | |
| 166 | /** |
| 167 | * test_and_set_bit - Set a bit and return its old value |
| 168 | * @nr: Bit to set |
| 169 | * @addr: Address to count from |
| 170 | * |
| 171 | * This operation is atomic and cannot be reordered. |
| 172 | * It also implies a memory barrier. |
| 173 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 174 | static inline int test_and_set_bit(int nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 175 | { |
| 176 | int oldbit; |
| 177 | |
| 178 | asm volatile(LOCK_PREFIX "bts %2,%1\n\t" |
Joe Perches | 286275c | 2008-03-23 01:01:45 -0700 | [diff] [blame] | 179 | "sbb %0,%0" : "=r" (oldbit), ADDR : "Ir" (nr) : "memory"); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 180 | |
| 181 | return oldbit; |
| 182 | } |
| 183 | |
| 184 | /** |
| 185 | * test_and_set_bit_lock - Set a bit and return its old value for lock |
| 186 | * @nr: Bit to set |
| 187 | * @addr: Address to count from |
| 188 | * |
| 189 | * This is the same as test_and_set_bit on x86. |
| 190 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 191 | static inline int test_and_set_bit_lock(int nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 192 | { |
| 193 | return test_and_set_bit(nr, addr); |
| 194 | } |
| 195 | |
| 196 | /** |
| 197 | * __test_and_set_bit - Set a bit and return its old value |
| 198 | * @nr: Bit to set |
| 199 | * @addr: Address to count from |
| 200 | * |
| 201 | * This operation is non-atomic and can be reordered. |
| 202 | * If two examples of this operation race, one can appear to succeed |
| 203 | * but actually fail. You must protect multiple accesses with a lock. |
| 204 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 205 | static inline int __test_and_set_bit(int nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 206 | { |
| 207 | int oldbit; |
| 208 | |
Simon Holm Thøgersen | eb2b4e6 | 2008-05-05 15:45:28 +0200 | [diff] [blame] | 209 | asm("bts %2,%1\n\t" |
| 210 | "sbb %0,%0" |
| 211 | : "=r" (oldbit), ADDR |
| 212 | : "Ir" (nr)); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 213 | return oldbit; |
| 214 | } |
| 215 | |
| 216 | /** |
| 217 | * test_and_clear_bit - Clear a bit and return its old value |
| 218 | * @nr: Bit to clear |
| 219 | * @addr: Address to count from |
| 220 | * |
| 221 | * This operation is atomic and cannot be reordered. |
| 222 | * It also implies a memory barrier. |
| 223 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 224 | static inline int test_and_clear_bit(int nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 225 | { |
| 226 | int oldbit; |
| 227 | |
| 228 | asm volatile(LOCK_PREFIX "btr %2,%1\n\t" |
| 229 | "sbb %0,%0" |
Joe Perches | 286275c | 2008-03-23 01:01:45 -0700 | [diff] [blame] | 230 | : "=r" (oldbit), ADDR : "Ir" (nr) : "memory"); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 231 | |
| 232 | return oldbit; |
| 233 | } |
| 234 | |
| 235 | /** |
| 236 | * __test_and_clear_bit - Clear a bit and return its old value |
| 237 | * @nr: Bit to clear |
| 238 | * @addr: Address to count from |
| 239 | * |
| 240 | * This operation is non-atomic and can be reordered. |
| 241 | * If two examples of this operation race, one can appear to succeed |
| 242 | * but actually fail. You must protect multiple accesses with a lock. |
| 243 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 244 | static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 245 | { |
| 246 | int oldbit; |
| 247 | |
Simon Holm Thøgersen | eb2b4e6 | 2008-05-05 15:45:28 +0200 | [diff] [blame] | 248 | asm volatile("btr %2,%1\n\t" |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 249 | "sbb %0,%0" |
Simon Holm Thøgersen | eb2b4e6 | 2008-05-05 15:45:28 +0200 | [diff] [blame] | 250 | : "=r" (oldbit), ADDR |
| 251 | : "Ir" (nr)); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 252 | return oldbit; |
| 253 | } |
| 254 | |
| 255 | /* WARNING: non atomic and it can be reordered! */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 256 | static inline int __test_and_change_bit(int nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 257 | { |
| 258 | int oldbit; |
| 259 | |
Simon Holm Thøgersen | eb2b4e6 | 2008-05-05 15:45:28 +0200 | [diff] [blame] | 260 | asm volatile("btc %2,%1\n\t" |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 261 | "sbb %0,%0" |
Simon Holm Thøgersen | eb2b4e6 | 2008-05-05 15:45:28 +0200 | [diff] [blame] | 262 | : "=r" (oldbit), ADDR |
| 263 | : "Ir" (nr) : "memory"); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 264 | |
| 265 | return oldbit; |
| 266 | } |
| 267 | |
| 268 | /** |
| 269 | * test_and_change_bit - Change a bit and return its old value |
| 270 | * @nr: Bit to change |
| 271 | * @addr: Address to count from |
| 272 | * |
| 273 | * This operation is atomic and cannot be reordered. |
| 274 | * It also implies a memory barrier. |
| 275 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 276 | static inline int test_and_change_bit(int nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 277 | { |
| 278 | int oldbit; |
| 279 | |
| 280 | asm volatile(LOCK_PREFIX "btc %2,%1\n\t" |
| 281 | "sbb %0,%0" |
Joe Perches | 286275c | 2008-03-23 01:01:45 -0700 | [diff] [blame] | 282 | : "=r" (oldbit), ADDR : "Ir" (nr) : "memory"); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 283 | |
| 284 | return oldbit; |
| 285 | } |
| 286 | |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 287 | static inline int constant_test_bit(int nr, const volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 288 | { |
Glauber de Oliveira Costa | 26996dd | 2008-01-30 13:31:31 +0100 | [diff] [blame] | 289 | return ((1UL << (nr % BITS_PER_LONG)) & |
| 290 | (((unsigned long *)addr)[nr / BITS_PER_LONG])) != 0; |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 291 | } |
| 292 | |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 293 | static inline int variable_test_bit(int nr, volatile const unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 294 | { |
| 295 | int oldbit; |
| 296 | |
Simon Holm Thøgersen | eb2b4e6 | 2008-05-05 15:45:28 +0200 | [diff] [blame] | 297 | asm volatile("bt %2,%1\n\t" |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 298 | "sbb %0,%0" |
| 299 | : "=r" (oldbit) |
Simon Holm Thøgersen | eb2b4e6 | 2008-05-05 15:45:28 +0200 | [diff] [blame] | 300 | : "m" (*(unsigned long *)addr), "Ir" (nr)); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 301 | |
| 302 | return oldbit; |
| 303 | } |
| 304 | |
| 305 | #if 0 /* Fool kernel-doc since it doesn't do macros yet */ |
| 306 | /** |
| 307 | * test_bit - Determine whether a bit is set |
| 308 | * @nr: bit number to test |
| 309 | * @addr: Address to start counting from |
| 310 | */ |
| 311 | static int test_bit(int nr, const volatile unsigned long *addr); |
| 312 | #endif |
| 313 | |
Joe Perches | f19dcf4 | 2008-03-23 01:03:07 -0700 | [diff] [blame] | 314 | #define test_bit(nr, addr) \ |
| 315 | (__builtin_constant_p((nr)) \ |
| 316 | ? constant_test_bit((nr), (addr)) \ |
| 317 | : variable_test_bit((nr), (addr))) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 318 | |
Alexander van Heukelum | 12d9c84 | 2008-03-15 13:04:42 +0100 | [diff] [blame] | 319 | /** |
| 320 | * __ffs - find first set bit in word |
| 321 | * @word: The word to search |
| 322 | * |
| 323 | * Undefined if no bit exists, so code should check against 0 first. |
| 324 | */ |
| 325 | static inline unsigned long __ffs(unsigned long word) |
| 326 | { |
Joe Perches | f19dcf4 | 2008-03-23 01:03:07 -0700 | [diff] [blame] | 327 | asm("bsf %1,%0" |
| 328 | : "=r" (word) |
| 329 | : "rm" (word)); |
Alexander van Heukelum | 12d9c84 | 2008-03-15 13:04:42 +0100 | [diff] [blame] | 330 | return word; |
| 331 | } |
| 332 | |
| 333 | /** |
| 334 | * ffz - find first zero bit in word |
| 335 | * @word: The word to search |
| 336 | * |
| 337 | * Undefined if no zero exists, so code should check against ~0UL first. |
| 338 | */ |
| 339 | static inline unsigned long ffz(unsigned long word) |
| 340 | { |
Joe Perches | f19dcf4 | 2008-03-23 01:03:07 -0700 | [diff] [blame] | 341 | asm("bsf %1,%0" |
| 342 | : "=r" (word) |
| 343 | : "r" (~word)); |
Alexander van Heukelum | 12d9c84 | 2008-03-15 13:04:42 +0100 | [diff] [blame] | 344 | return word; |
| 345 | } |
| 346 | |
| 347 | /* |
| 348 | * __fls: find last set bit in word |
| 349 | * @word: The word to search |
| 350 | * |
| 351 | * Undefined if no zero exists, so code should check against ~0UL first. |
| 352 | */ |
| 353 | static inline unsigned long __fls(unsigned long word) |
| 354 | { |
Joe Perches | f19dcf4 | 2008-03-23 01:03:07 -0700 | [diff] [blame] | 355 | asm("bsr %1,%0" |
| 356 | : "=r" (word) |
| 357 | : "rm" (word)); |
Alexander van Heukelum | 12d9c84 | 2008-03-15 13:04:42 +0100 | [diff] [blame] | 358 | return word; |
| 359 | } |
| 360 | |
| 361 | #ifdef __KERNEL__ |
| 362 | /** |
| 363 | * ffs - find first set bit in word |
| 364 | * @x: the word to search |
| 365 | * |
| 366 | * This is defined the same way as the libc and compiler builtin ffs |
| 367 | * routines, therefore differs in spirit from the other bitops. |
| 368 | * |
| 369 | * ffs(value) returns 0 if value is 0 or the position of the first |
| 370 | * set bit if value is nonzero. The first (least significant) bit |
| 371 | * is at position 1. |
| 372 | */ |
| 373 | static inline int ffs(int x) |
| 374 | { |
| 375 | int r; |
| 376 | #ifdef CONFIG_X86_CMOV |
Joe Perches | f19dcf4 | 2008-03-23 01:03:07 -0700 | [diff] [blame] | 377 | asm("bsfl %1,%0\n\t" |
| 378 | "cmovzl %2,%0" |
| 379 | : "=r" (r) : "rm" (x), "r" (-1)); |
Alexander van Heukelum | 12d9c84 | 2008-03-15 13:04:42 +0100 | [diff] [blame] | 380 | #else |
Joe Perches | f19dcf4 | 2008-03-23 01:03:07 -0700 | [diff] [blame] | 381 | asm("bsfl %1,%0\n\t" |
| 382 | "jnz 1f\n\t" |
| 383 | "movl $-1,%0\n" |
| 384 | "1:" : "=r" (r) : "rm" (x)); |
Alexander van Heukelum | 12d9c84 | 2008-03-15 13:04:42 +0100 | [diff] [blame] | 385 | #endif |
| 386 | return r + 1; |
| 387 | } |
| 388 | |
| 389 | /** |
| 390 | * fls - find last set bit in word |
| 391 | * @x: the word to search |
| 392 | * |
| 393 | * This is defined in a similar way as the libc and compiler builtin |
| 394 | * ffs, but returns the position of the most significant set bit. |
| 395 | * |
| 396 | * fls(value) returns 0 if value is 0 or the position of the last |
| 397 | * set bit if value is nonzero. The last (most significant) bit is |
| 398 | * at position 32. |
| 399 | */ |
| 400 | static inline int fls(int x) |
| 401 | { |
| 402 | int r; |
| 403 | #ifdef CONFIG_X86_CMOV |
Joe Perches | f19dcf4 | 2008-03-23 01:03:07 -0700 | [diff] [blame] | 404 | asm("bsrl %1,%0\n\t" |
| 405 | "cmovzl %2,%0" |
| 406 | : "=&r" (r) : "rm" (x), "rm" (-1)); |
Alexander van Heukelum | 12d9c84 | 2008-03-15 13:04:42 +0100 | [diff] [blame] | 407 | #else |
Joe Perches | f19dcf4 | 2008-03-23 01:03:07 -0700 | [diff] [blame] | 408 | asm("bsrl %1,%0\n\t" |
| 409 | "jnz 1f\n\t" |
| 410 | "movl $-1,%0\n" |
| 411 | "1:" : "=r" (r) : "rm" (x)); |
Alexander van Heukelum | 12d9c84 | 2008-03-15 13:04:42 +0100 | [diff] [blame] | 412 | #endif |
| 413 | return r + 1; |
| 414 | } |
| 415 | #endif /* __KERNEL__ */ |
| 416 | |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 417 | #undef ADDR |
| 418 | |
Alexander van Heukelum | d66462f | 2008-04-04 20:49:30 +0200 | [diff] [blame] | 419 | static inline void set_bit_string(unsigned long *bitmap, |
| 420 | unsigned long i, int len) |
| 421 | { |
| 422 | unsigned long end = i + len; |
| 423 | while (i < end) { |
| 424 | __set_bit(i, bitmap); |
| 425 | i++; |
| 426 | } |
| 427 | } |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 428 | |
Alexander van Heukelum | d66462f | 2008-04-04 20:49:30 +0200 | [diff] [blame] | 429 | #ifdef __KERNEL__ |
| 430 | |
| 431 | #include <asm-generic/bitops/sched.h> |
| 432 | |
| 433 | #define ARCH_HAS_FAST_MULTIPLIER 1 |
| 434 | |
| 435 | #include <asm-generic/bitops/hweight.h> |
| 436 | |
| 437 | #endif /* __KERNEL__ */ |
| 438 | |
| 439 | #include <asm-generic/bitops/fls64.h> |
| 440 | |
| 441 | #ifdef __KERNEL__ |
| 442 | |
| 443 | #include <asm-generic/bitops/ext2-non-atomic.h> |
| 444 | |
| 445 | #define ext2_set_bit_atomic(lock, nr, addr) \ |
| 446 | test_and_set_bit((nr), (unsigned long *)(addr)) |
| 447 | #define ext2_clear_bit_atomic(lock, nr, addr) \ |
| 448 | test_and_clear_bit((nr), (unsigned long *)(addr)) |
| 449 | |
| 450 | #include <asm-generic/bitops/minix.h> |
| 451 | |
| 452 | #endif /* __KERNEL__ */ |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 453 | #endif /* _ASM_X86_BITOPS_H */ |