H. Peter Anvin | 1965aae | 2008-10-22 22:26:29 -0700 | [diff] [blame^] | 1 | #ifndef _ASM_X86_BITOPS_H |
| 2 | #define _ASM_X86_BITOPS_H |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 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 | |
Ingo Molnar | 7dbceaf | 2008-06-20 07:28:24 +0200 | [diff] [blame] | 31 | #define ADDR BITOP_ADDR(addr) |
Linus Torvalds | 1a750e0 | 2008-06-18 21:03:26 -0700 | [diff] [blame] | 32 | |
| 33 | /* |
| 34 | * We do the locked ops that don't return the old value as |
| 35 | * a mask operation on a byte. |
| 36 | */ |
Ingo Molnar | 7dbceaf | 2008-06-20 07:28:24 +0200 | [diff] [blame] | 37 | #define IS_IMMEDIATE(nr) (__builtin_constant_p(nr)) |
| 38 | #define CONST_MASK_ADDR(nr, addr) BITOP_ADDR((void *)(addr) + ((nr)>>3)) |
| 39 | #define CONST_MASK(nr) (1 << ((nr) & 7)) |
Linus Torvalds | 1a750e0 | 2008-06-18 21:03:26 -0700 | [diff] [blame] | 40 | |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 41 | /** |
| 42 | * set_bit - Atomically set a bit in memory |
| 43 | * @nr: the bit to set |
| 44 | * @addr: the address to start counting from |
| 45 | * |
| 46 | * This function is atomic and may not be reordered. See __set_bit() |
| 47 | * if you do not require the atomic guarantees. |
| 48 | * |
| 49 | * Note: there are no guarantees that this function will not be reordered |
| 50 | * on non x86 architectures, so if you are writing portable code, |
| 51 | * make sure not to rely on its reordering guarantees. |
| 52 | * |
| 53 | * Note that @nr may be almost arbitrarily large; this function is not |
| 54 | * restricted to acting on a single-word quantity. |
| 55 | */ |
Linus Torvalds | 1a750e0 | 2008-06-18 21:03:26 -0700 | [diff] [blame] | 56 | static inline void set_bit(unsigned int nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 57 | { |
Ingo Molnar | 7dbceaf | 2008-06-20 07:28:24 +0200 | [diff] [blame] | 58 | if (IS_IMMEDIATE(nr)) { |
| 59 | asm volatile(LOCK_PREFIX "orb %1,%0" |
| 60 | : CONST_MASK_ADDR(nr, addr) |
Ingo Molnar | 437a0a5 | 2008-06-20 21:50:20 +0200 | [diff] [blame] | 61 | : "iq" ((u8)CONST_MASK(nr)) |
Ingo Molnar | 7dbceaf | 2008-06-20 07:28:24 +0200 | [diff] [blame] | 62 | : "memory"); |
| 63 | } else { |
| 64 | asm volatile(LOCK_PREFIX "bts %1,%0" |
| 65 | : BITOP_ADDR(addr) : "Ir" (nr) : "memory"); |
| 66 | } |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 67 | } |
| 68 | |
| 69 | /** |
| 70 | * __set_bit - Set a bit in memory |
| 71 | * @nr: the bit to set |
| 72 | * @addr: the address to start counting from |
| 73 | * |
| 74 | * Unlike set_bit(), this function is non-atomic and may be reordered. |
| 75 | * If it's called on the same region of memory simultaneously, the effect |
| 76 | * may be that only one operation succeeds. |
| 77 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 78 | static inline void __set_bit(int nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 79 | { |
Joe Perches | f19dcf4 | 2008-03-23 01:03:07 -0700 | [diff] [blame] | 80 | asm volatile("bts %1,%0" : ADDR : "Ir" (nr) : "memory"); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 81 | } |
| 82 | |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 83 | /** |
| 84 | * clear_bit - Clears a bit in memory |
| 85 | * @nr: Bit to clear |
| 86 | * @addr: Address to start counting from |
| 87 | * |
| 88 | * clear_bit() is atomic and may not be reordered. However, it does |
| 89 | * not contain a memory barrier, so if it is used for locking purposes, |
| 90 | * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit() |
| 91 | * in order to ensure changes are visible on other processors. |
| 92 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 93 | static inline void clear_bit(int nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 94 | { |
Ingo Molnar | 7dbceaf | 2008-06-20 07:28:24 +0200 | [diff] [blame] | 95 | if (IS_IMMEDIATE(nr)) { |
| 96 | asm volatile(LOCK_PREFIX "andb %1,%0" |
| 97 | : CONST_MASK_ADDR(nr, addr) |
Ingo Molnar | 437a0a5 | 2008-06-20 21:50:20 +0200 | [diff] [blame] | 98 | : "iq" ((u8)~CONST_MASK(nr))); |
Ingo Molnar | 7dbceaf | 2008-06-20 07:28:24 +0200 | [diff] [blame] | 99 | } else { |
| 100 | asm volatile(LOCK_PREFIX "btr %1,%0" |
| 101 | : BITOP_ADDR(addr) |
| 102 | : "Ir" (nr)); |
| 103 | } |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 104 | } |
| 105 | |
| 106 | /* |
| 107 | * clear_bit_unlock - Clears a bit in memory |
| 108 | * @nr: Bit to clear |
| 109 | * @addr: Address to start counting from |
| 110 | * |
| 111 | * clear_bit() is atomic and implies release semantics before the memory |
| 112 | * operation. It can be used for an unlock. |
| 113 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 114 | static inline void clear_bit_unlock(unsigned nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 115 | { |
| 116 | barrier(); |
| 117 | clear_bit(nr, addr); |
| 118 | } |
| 119 | |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 120 | static inline void __clear_bit(int nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 121 | { |
Simon Holm Thøgersen | eb2b4e6 | 2008-05-05 15:45:28 +0200 | [diff] [blame] | 122 | asm volatile("btr %1,%0" : ADDR : "Ir" (nr)); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 123 | } |
| 124 | |
| 125 | /* |
| 126 | * __clear_bit_unlock - Clears a bit in memory |
| 127 | * @nr: Bit to clear |
| 128 | * @addr: Address to start counting from |
| 129 | * |
| 130 | * __clear_bit() is non-atomic and implies release semantics before the memory |
| 131 | * operation. It can be used for an unlock if no other CPUs can concurrently |
| 132 | * modify other bits in the word. |
| 133 | * |
| 134 | * No memory barrier is required here, because x86 cannot reorder stores past |
| 135 | * older loads. Same principle as spin_unlock. |
| 136 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 137 | static inline void __clear_bit_unlock(unsigned nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 138 | { |
| 139 | barrier(); |
| 140 | __clear_bit(nr, addr); |
| 141 | } |
| 142 | |
| 143 | #define smp_mb__before_clear_bit() barrier() |
| 144 | #define smp_mb__after_clear_bit() barrier() |
| 145 | |
| 146 | /** |
| 147 | * __change_bit - Toggle a bit in memory |
| 148 | * @nr: the bit to change |
| 149 | * @addr: the address to start counting from |
| 150 | * |
| 151 | * Unlike change_bit(), this function is non-atomic and may be reordered. |
| 152 | * If it's called on the same region of memory simultaneously, the effect |
| 153 | * may be that only one operation succeeds. |
| 154 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 155 | static inline void __change_bit(int nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 156 | { |
Simon Holm Thøgersen | eb2b4e6 | 2008-05-05 15:45:28 +0200 | [diff] [blame] | 157 | asm volatile("btc %1,%0" : ADDR : "Ir" (nr)); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 158 | } |
| 159 | |
| 160 | /** |
| 161 | * change_bit - Toggle a bit in memory |
| 162 | * @nr: Bit to change |
| 163 | * @addr: Address to start counting from |
| 164 | * |
| 165 | * change_bit() is atomic and may not be reordered. |
| 166 | * Note that @nr may be almost arbitrarily large; this function is not |
| 167 | * restricted to acting on a single-word quantity. |
| 168 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 169 | static inline void change_bit(int nr, volatile unsigned long *addr) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 170 | { |
Simon Holm Thøgersen | eb2b4e6 | 2008-05-05 15:45:28 +0200 | [diff] [blame] | 171 | asm volatile(LOCK_PREFIX "btc %1,%0" : ADDR : "Ir" (nr)); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 172 | } |
| 173 | |
| 174 | /** |
| 175 | * test_and_set_bit - Set a bit and return its old value |
| 176 | * @nr: Bit to set |
| 177 | * @addr: Address to count from |
| 178 | * |
| 179 | * This operation is atomic and cannot be reordered. |
| 180 | * It also implies a memory barrier. |
| 181 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 182 | 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] | 183 | { |
| 184 | int oldbit; |
| 185 | |
| 186 | asm volatile(LOCK_PREFIX "bts %2,%1\n\t" |
Joe Perches | 286275c | 2008-03-23 01:01:45 -0700 | [diff] [blame] | 187 | "sbb %0,%0" : "=r" (oldbit), ADDR : "Ir" (nr) : "memory"); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 188 | |
| 189 | return oldbit; |
| 190 | } |
| 191 | |
| 192 | /** |
| 193 | * test_and_set_bit_lock - Set a bit and return its old value for lock |
| 194 | * @nr: Bit to set |
| 195 | * @addr: Address to count from |
| 196 | * |
| 197 | * This is the same as test_and_set_bit on x86. |
| 198 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 199 | 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] | 200 | { |
| 201 | return test_and_set_bit(nr, addr); |
| 202 | } |
| 203 | |
| 204 | /** |
| 205 | * __test_and_set_bit - Set a bit and return its old value |
| 206 | * @nr: Bit to set |
| 207 | * @addr: Address to count from |
| 208 | * |
| 209 | * This operation is non-atomic and can be reordered. |
| 210 | * If two examples of this operation race, one can appear to succeed |
| 211 | * but actually fail. You must protect multiple accesses with a lock. |
| 212 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 213 | 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] | 214 | { |
| 215 | int oldbit; |
| 216 | |
Simon Holm Thøgersen | eb2b4e6 | 2008-05-05 15:45:28 +0200 | [diff] [blame] | 217 | asm("bts %2,%1\n\t" |
| 218 | "sbb %0,%0" |
| 219 | : "=r" (oldbit), ADDR |
| 220 | : "Ir" (nr)); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 221 | return oldbit; |
| 222 | } |
| 223 | |
| 224 | /** |
| 225 | * test_and_clear_bit - Clear a bit and return its old value |
| 226 | * @nr: Bit to clear |
| 227 | * @addr: Address to count from |
| 228 | * |
| 229 | * This operation is atomic and cannot be reordered. |
| 230 | * It also implies a memory barrier. |
| 231 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 232 | 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] | 233 | { |
| 234 | int oldbit; |
| 235 | |
| 236 | asm volatile(LOCK_PREFIX "btr %2,%1\n\t" |
| 237 | "sbb %0,%0" |
Joe Perches | 286275c | 2008-03-23 01:01:45 -0700 | [diff] [blame] | 238 | : "=r" (oldbit), ADDR : "Ir" (nr) : "memory"); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 239 | |
| 240 | return oldbit; |
| 241 | } |
| 242 | |
| 243 | /** |
| 244 | * __test_and_clear_bit - Clear a bit and return its old value |
| 245 | * @nr: Bit to clear |
| 246 | * @addr: Address to count from |
| 247 | * |
| 248 | * This operation is non-atomic and can be reordered. |
| 249 | * If two examples of this operation race, one can appear to succeed |
| 250 | * but actually fail. You must protect multiple accesses with a lock. |
| 251 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 252 | 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] | 253 | { |
| 254 | int oldbit; |
| 255 | |
Simon Holm Thøgersen | eb2b4e6 | 2008-05-05 15:45:28 +0200 | [diff] [blame] | 256 | asm volatile("btr %2,%1\n\t" |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 257 | "sbb %0,%0" |
Simon Holm Thøgersen | eb2b4e6 | 2008-05-05 15:45:28 +0200 | [diff] [blame] | 258 | : "=r" (oldbit), ADDR |
| 259 | : "Ir" (nr)); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 260 | return oldbit; |
| 261 | } |
| 262 | |
| 263 | /* WARNING: non atomic and it can be reordered! */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 264 | 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] | 265 | { |
| 266 | int oldbit; |
| 267 | |
Simon Holm Thøgersen | eb2b4e6 | 2008-05-05 15:45:28 +0200 | [diff] [blame] | 268 | asm volatile("btc %2,%1\n\t" |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 269 | "sbb %0,%0" |
Simon Holm Thøgersen | eb2b4e6 | 2008-05-05 15:45:28 +0200 | [diff] [blame] | 270 | : "=r" (oldbit), ADDR |
| 271 | : "Ir" (nr) : "memory"); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 272 | |
| 273 | return oldbit; |
| 274 | } |
| 275 | |
| 276 | /** |
| 277 | * test_and_change_bit - Change a bit and return its old value |
| 278 | * @nr: Bit to change |
| 279 | * @addr: Address to count from |
| 280 | * |
| 281 | * This operation is atomic and cannot be reordered. |
| 282 | * It also implies a memory barrier. |
| 283 | */ |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 284 | 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] | 285 | { |
| 286 | int oldbit; |
| 287 | |
| 288 | asm volatile(LOCK_PREFIX "btc %2,%1\n\t" |
| 289 | "sbb %0,%0" |
Joe Perches | 286275c | 2008-03-23 01:01:45 -0700 | [diff] [blame] | 290 | : "=r" (oldbit), ADDR : "Ir" (nr) : "memory"); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 291 | |
| 292 | return oldbit; |
| 293 | } |
| 294 | |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 295 | 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] | 296 | { |
Glauber de Oliveira Costa | 26996dd | 2008-01-30 13:31:31 +0100 | [diff] [blame] | 297 | return ((1UL << (nr % BITS_PER_LONG)) & |
| 298 | (((unsigned long *)addr)[nr / BITS_PER_LONG])) != 0; |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 299 | } |
| 300 | |
Andrew Morton | 5136dea | 2008-05-14 16:10:41 -0700 | [diff] [blame] | 301 | 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] | 302 | { |
| 303 | int oldbit; |
| 304 | |
Simon Holm Thøgersen | eb2b4e6 | 2008-05-05 15:45:28 +0200 | [diff] [blame] | 305 | asm volatile("bt %2,%1\n\t" |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 306 | "sbb %0,%0" |
| 307 | : "=r" (oldbit) |
Simon Holm Thøgersen | eb2b4e6 | 2008-05-05 15:45:28 +0200 | [diff] [blame] | 308 | : "m" (*(unsigned long *)addr), "Ir" (nr)); |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 309 | |
| 310 | return oldbit; |
| 311 | } |
| 312 | |
| 313 | #if 0 /* Fool kernel-doc since it doesn't do macros yet */ |
| 314 | /** |
| 315 | * test_bit - Determine whether a bit is set |
| 316 | * @nr: bit number to test |
| 317 | * @addr: Address to start counting from |
| 318 | */ |
| 319 | static int test_bit(int nr, const volatile unsigned long *addr); |
| 320 | #endif |
| 321 | |
Joe Perches | f19dcf4 | 2008-03-23 01:03:07 -0700 | [diff] [blame] | 322 | #define test_bit(nr, addr) \ |
| 323 | (__builtin_constant_p((nr)) \ |
| 324 | ? constant_test_bit((nr), (addr)) \ |
| 325 | : variable_test_bit((nr), (addr))) |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 326 | |
Alexander van Heukelum | 12d9c84 | 2008-03-15 13:04:42 +0100 | [diff] [blame] | 327 | /** |
| 328 | * __ffs - find first set bit in word |
| 329 | * @word: The word to search |
| 330 | * |
| 331 | * Undefined if no bit exists, so code should check against 0 first. |
| 332 | */ |
| 333 | static inline unsigned long __ffs(unsigned long word) |
| 334 | { |
Joe Perches | f19dcf4 | 2008-03-23 01:03:07 -0700 | [diff] [blame] | 335 | asm("bsf %1,%0" |
| 336 | : "=r" (word) |
| 337 | : "rm" (word)); |
Alexander van Heukelum | 12d9c84 | 2008-03-15 13:04:42 +0100 | [diff] [blame] | 338 | return word; |
| 339 | } |
| 340 | |
| 341 | /** |
| 342 | * ffz - find first zero bit in word |
| 343 | * @word: The word to search |
| 344 | * |
| 345 | * Undefined if no zero exists, so code should check against ~0UL first. |
| 346 | */ |
| 347 | static inline unsigned long ffz(unsigned long word) |
| 348 | { |
Joe Perches | f19dcf4 | 2008-03-23 01:03:07 -0700 | [diff] [blame] | 349 | asm("bsf %1,%0" |
| 350 | : "=r" (word) |
| 351 | : "r" (~word)); |
Alexander van Heukelum | 12d9c84 | 2008-03-15 13:04:42 +0100 | [diff] [blame] | 352 | return word; |
| 353 | } |
| 354 | |
| 355 | /* |
| 356 | * __fls: find last set bit in word |
| 357 | * @word: The word to search |
| 358 | * |
Alexander van Heukelum | 8450e85 | 2008-07-05 19:53:46 +0200 | [diff] [blame] | 359 | * Undefined if no set bit exists, so code should check against 0 first. |
Alexander van Heukelum | 12d9c84 | 2008-03-15 13:04:42 +0100 | [diff] [blame] | 360 | */ |
| 361 | static inline unsigned long __fls(unsigned long word) |
| 362 | { |
Joe Perches | f19dcf4 | 2008-03-23 01:03:07 -0700 | [diff] [blame] | 363 | asm("bsr %1,%0" |
| 364 | : "=r" (word) |
| 365 | : "rm" (word)); |
Alexander van Heukelum | 12d9c84 | 2008-03-15 13:04:42 +0100 | [diff] [blame] | 366 | return word; |
| 367 | } |
| 368 | |
| 369 | #ifdef __KERNEL__ |
| 370 | /** |
| 371 | * ffs - find first set bit in word |
| 372 | * @x: the word to search |
| 373 | * |
| 374 | * This is defined the same way as the libc and compiler builtin ffs |
| 375 | * routines, therefore differs in spirit from the other bitops. |
| 376 | * |
| 377 | * ffs(value) returns 0 if value is 0 or the position of the first |
| 378 | * set bit if value is nonzero. The first (least significant) bit |
| 379 | * is at position 1. |
| 380 | */ |
| 381 | static inline int ffs(int x) |
| 382 | { |
| 383 | int r; |
| 384 | #ifdef CONFIG_X86_CMOV |
Joe Perches | f19dcf4 | 2008-03-23 01:03:07 -0700 | [diff] [blame] | 385 | asm("bsfl %1,%0\n\t" |
| 386 | "cmovzl %2,%0" |
| 387 | : "=r" (r) : "rm" (x), "r" (-1)); |
Alexander van Heukelum | 12d9c84 | 2008-03-15 13:04:42 +0100 | [diff] [blame] | 388 | #else |
Joe Perches | f19dcf4 | 2008-03-23 01:03:07 -0700 | [diff] [blame] | 389 | asm("bsfl %1,%0\n\t" |
| 390 | "jnz 1f\n\t" |
| 391 | "movl $-1,%0\n" |
| 392 | "1:" : "=r" (r) : "rm" (x)); |
Alexander van Heukelum | 12d9c84 | 2008-03-15 13:04:42 +0100 | [diff] [blame] | 393 | #endif |
| 394 | return r + 1; |
| 395 | } |
| 396 | |
| 397 | /** |
| 398 | * fls - find last set bit in word |
| 399 | * @x: the word to search |
| 400 | * |
| 401 | * This is defined in a similar way as the libc and compiler builtin |
| 402 | * ffs, but returns the position of the most significant set bit. |
| 403 | * |
| 404 | * fls(value) returns 0 if value is 0 or the position of the last |
| 405 | * set bit if value is nonzero. The last (most significant) bit is |
| 406 | * at position 32. |
| 407 | */ |
| 408 | static inline int fls(int x) |
| 409 | { |
| 410 | int r; |
| 411 | #ifdef CONFIG_X86_CMOV |
Joe Perches | f19dcf4 | 2008-03-23 01:03:07 -0700 | [diff] [blame] | 412 | asm("bsrl %1,%0\n\t" |
| 413 | "cmovzl %2,%0" |
| 414 | : "=&r" (r) : "rm" (x), "rm" (-1)); |
Alexander van Heukelum | 12d9c84 | 2008-03-15 13:04:42 +0100 | [diff] [blame] | 415 | #else |
Joe Perches | f19dcf4 | 2008-03-23 01:03:07 -0700 | [diff] [blame] | 416 | asm("bsrl %1,%0\n\t" |
| 417 | "jnz 1f\n\t" |
| 418 | "movl $-1,%0\n" |
| 419 | "1:" : "=r" (r) : "rm" (x)); |
Alexander van Heukelum | 12d9c84 | 2008-03-15 13:04:42 +0100 | [diff] [blame] | 420 | #endif |
| 421 | return r + 1; |
| 422 | } |
| 423 | #endif /* __KERNEL__ */ |
| 424 | |
Jeremy Fitzhardinge | 1c54d77 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 425 | #undef ADDR |
| 426 | |
Alexander van Heukelum | d66462f | 2008-04-04 20:49:30 +0200 | [diff] [blame] | 427 | #ifdef __KERNEL__ |
| 428 | |
| 429 | #include <asm-generic/bitops/sched.h> |
| 430 | |
| 431 | #define ARCH_HAS_FAST_MULTIPLIER 1 |
| 432 | |
| 433 | #include <asm-generic/bitops/hweight.h> |
| 434 | |
| 435 | #endif /* __KERNEL__ */ |
| 436 | |
| 437 | #include <asm-generic/bitops/fls64.h> |
| 438 | |
| 439 | #ifdef __KERNEL__ |
| 440 | |
| 441 | #include <asm-generic/bitops/ext2-non-atomic.h> |
| 442 | |
| 443 | #define ext2_set_bit_atomic(lock, nr, addr) \ |
| 444 | test_and_set_bit((nr), (unsigned long *)(addr)) |
| 445 | #define ext2_clear_bit_atomic(lock, nr, addr) \ |
| 446 | test_and_clear_bit((nr), (unsigned long *)(addr)) |
| 447 | |
| 448 | #include <asm-generic/bitops/minix.h> |
| 449 | |
| 450 | #endif /* __KERNEL__ */ |
H. Peter Anvin | 1965aae | 2008-10-22 22:26:29 -0700 | [diff] [blame^] | 451 | #endif /* _ASM_X86_BITOPS_H */ |