include/asm-x86/bitops_64.h

   1 #ifndef _X86_64_BITOPS_H
   2 #define _X86_64_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 <asm/alternative.h>
  13
  14 #if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 1)
  15 /* Technically wrong, but this avoids compilation errors on some gcc
  16    versions. */
  17 #define ADDR "=m" (*(volatile long *) addr)
  18 #else
  19 #define ADDR "+m" (*(volatile long *) addr)
  20 #endif
  21
  22 /**
  23  * set_bit - Atomically set a bit in memory
  24  * @nr: the bit to set
  25  * @addr: the address to start counting from
  26  *
  27  * This function is atomic and may not be reordered.  See __set_bit()
  28  * if you do not require the atomic guarantees.
  29  * Note that @nr may be almost arbitrarily large; this function is not
  30  * restricted to acting on a single-word quantity.
  31  */
  32 static __inline__ void set_bit(int nr, volatile void * addr)
  33 {
  34         __asm__ __volatile__( LOCK_PREFIX
  35                 "btsl %1,%0"
  36                 :ADDR
  37                 :"dIr" (nr) : "memory");
  38 }
  39
  40 /**
  41  * __set_bit - Set a bit in memory
  42  * @nr: the bit to set
  43  * @addr: the address to start counting from
  44  *
  45  * Unlike set_bit(), this function is non-atomic and may be reordered.
  46  * If it's called on the same region of memory simultaneously, the effect
  47  * may be that only one operation succeeds.
  48  */
  49 static __inline__ void __set_bit(int nr, volatile void * addr)
  50 {
  51         __asm__ volatile(
  52                 "btsl %1,%0"
  53                 :ADDR
  54                 :"dIr" (nr) : "memory");
  55 }
  56
  57 /**
  58  * clear_bit - Clears a bit in memory
  59  * @nr: Bit to clear
  60  * @addr: Address to start counting from
  61  *
  62  * clear_bit() is atomic and may not be reordered.  However, it does
  63  * not contain a memory barrier, so if it is used for locking purposes,
  64  * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
  65  * in order to ensure changes are visible on other processors.
  66  */
  67 static __inline__ void clear_bit(int nr, volatile void * addr)
  68 {
  69         __asm__ __volatile__( LOCK_PREFIX
  70                 "btrl %1,%0"
  71                 :ADDR
  72                 :"dIr" (nr));
  73 }
  74
  75 static __inline__ void __clear_bit(int nr, volatile void * addr)
  76 {
  77         __asm__ __volatile__(
  78                 "btrl %1,%0"
  79                 :ADDR
  80                 :"dIr" (nr));
  81 }
  82
  83 #define smp_mb__before_clear_bit()      barrier()
  84 #define smp_mb__after_clear_bit()       barrier()
  85
  86 /**
  87  * __change_bit - Toggle a bit in memory
  88  * @nr: the bit to change
  89  * @addr: the address to start counting from
  90  *
  91  * Unlike change_bit(), this function is non-atomic and may be reordered.
  92  * If it's called on the same region of memory simultaneously, the effect
  93  * may be that only one operation succeeds.
  94  */
  95 static __inline__ void __change_bit(int nr, volatile void * addr)
  96 {
  97         __asm__ __volatile__(
  98                 "btcl %1,%0"
  99                 :ADDR
 100                 :"dIr" (nr));
 101 }
 102
 103 /**
 104  * change_bit - Toggle a bit in memory
 105  * @nr: Bit to change
 106  * @addr: Address to start counting from
 107  *
 108  * change_bit() is atomic and may not be reordered.
 109  * Note that @nr may be almost arbitrarily large; this function is not
 110  * restricted to acting on a single-word quantity.
 111  */
 112 static __inline__ void change_bit(int nr, volatile void * addr)
 113 {
 114         __asm__ __volatile__( LOCK_PREFIX
 115                 "btcl %1,%0"
 116                 :ADDR
 117                 :"dIr" (nr));
 118 }
 119
 120 /**
 121  * test_and_set_bit - Set a bit and return its old value
 122  * @nr: Bit to set
 123  * @addr: Address to count from
 124  *
 125  * This operation is atomic and cannot be reordered.
 126  * It also implies a memory barrier.
 127  */
 128 static __inline__ int test_and_set_bit(int nr, volatile void * addr)
 129 {
 130         int oldbit;
 131
 132         __asm__ __volatile__( LOCK_PREFIX
 133                 "btsl %2,%1\n\tsbbl %0,%0"
 134                 :"=r" (oldbit),ADDR
 135                 :"dIr" (nr) : "memory");
 136         return oldbit;
 137 }
 138
 139 /**
 140  * __test_and_set_bit - Set a bit and return its old value
 141  * @nr: Bit to set
 142  * @addr: Address to count from
 143  *
 144  * This operation is non-atomic and can be reordered.
 145  * If two examples of this operation race, one can appear to succeed
 146  * but actually fail.  You must protect multiple accesses with a lock.
 147  */
 148 static __inline__ int __test_and_set_bit(int nr, volatile void * addr)
 149 {
 150         int oldbit;
 151
 152         __asm__(
 153                 "btsl %2,%1\n\tsbbl %0,%0"
 154                 :"=r" (oldbit),ADDR
 155                 :"dIr" (nr));
 156         return oldbit;
 157 }
 158
 159 /**
 160  * test_and_clear_bit - Clear a bit and return its old value
 161  * @nr: Bit to clear
 162  * @addr: Address to count from
 163  *
 164  * This operation is atomic and cannot be reordered.
 165  * It also implies a memory barrier.
 166  */
 167 static __inline__ int test_and_clear_bit(int nr, volatile void * addr)
 168 {
 169         int oldbit;
 170
 171         __asm__ __volatile__( LOCK_PREFIX
 172                 "btrl %2,%1\n\tsbbl %0,%0"
 173                 :"=r" (oldbit),ADDR
 174                 :"dIr" (nr) : "memory");
 175         return oldbit;
 176 }
 177
 178 /**
 179  * __test_and_clear_bit - Clear a bit and return its old value
 180  * @nr: Bit to clear
 181  * @addr: Address to count from
 182  *
 183  * This operation is non-atomic and can be reordered.
 184  * If two examples of this operation race, one can appear to succeed
 185  * but actually fail.  You must protect multiple accesses with a lock.
 186  */
 187 static __inline__ int __test_and_clear_bit(int nr, volatile void * addr)
 188 {
 189         int oldbit;
 190
 191         __asm__(
 192                 "btrl %2,%1\n\tsbbl %0,%0"
 193                 :"=r" (oldbit),ADDR
 194                 :"dIr" (nr));
 195         return oldbit;
 196 }
 197
 198 /* WARNING: non atomic and it can be reordered! */
 199 static __inline__ int __test_and_change_bit(int nr, volatile void * addr)
 200 {
 201         int oldbit;
 202
 203         __asm__ __volatile__(
 204                 "btcl %2,%1\n\tsbbl %0,%0"
 205                 :"=r" (oldbit),ADDR
 206                 :"dIr" (nr) : "memory");
 207         return oldbit;
 208 }
 209
 210 /**
 211  * test_and_change_bit - Change a bit and return its old value
 212  * @nr: Bit to change
 213  * @addr: Address to count from
 214  *
 215  * This operation is atomic and cannot be reordered.
 216  * It also implies a memory barrier.
 217  */
 218 static __inline__ int test_and_change_bit(int nr, volatile void * addr)
 219 {
 220         int oldbit;
 221
 222         __asm__ __volatile__( LOCK_PREFIX
 223                 "btcl %2,%1\n\tsbbl %0,%0"
 224                 :"=r" (oldbit),ADDR
 225                 :"dIr" (nr) : "memory");
 226         return oldbit;
 227 }
 228
 229 #if 0 /* Fool kernel-doc since it doesn't do macros yet */
 230 /**
 231  * test_bit - Determine whether a bit is set
 232  * @nr: bit number to test
 233  * @addr: Address to start counting from
 234  */
 235 static int test_bit(int nr, const volatile void * addr);
 236 #endif
 237
 238 static __inline__ int constant_test_bit(int nr, const volatile void * addr)
 239 {
 240         return ((1UL << (nr & 31)) & (((const volatile unsigned int *) addr)[nr >> 5])) != 0;
 241 }
 242
 243 static __inline__ int variable_test_bit(int nr, volatile const void * addr)
 244 {
 245         int oldbit;
 246
 247         __asm__ __volatile__(
 248                 "btl %2,%1\n\tsbbl %0,%0"
 249                 :"=r" (oldbit)
 250                 :"m" (*(volatile long *)addr),"dIr" (nr));
 251         return oldbit;
 252 }
 253
 254 #define test_bit(nr,addr) \
 255 (__builtin_constant_p(nr) ? \
 256  constant_test_bit((nr),(addr)) : \
 257  variable_test_bit((nr),(addr)))
 258
 259 #undef ADDR
 260
 261 extern long find_first_zero_bit(const unsigned long * addr, unsigned long size);
 262 extern long find_next_zero_bit (const unsigned long * addr, long size, long offset);
 263 extern long find_first_bit(const unsigned long * addr, unsigned long size);
 264 extern long find_next_bit(const unsigned long * addr, long size, long offset);
 265
 266 /* return index of first bet set in val or max when no bit is set */
 267 static inline long __scanbit(unsigned long val, unsigned long max)
 268 {
 269         asm("bsfq %1,%0 ; cmovz %2,%0" : "=&r" (val) : "r" (val), "r" (max));
 270         return val;
 271 }
 272
 273 #define find_first_bit(addr,size) \
 274 ((__builtin_constant_p(size) && (size) <= BITS_PER_LONG ? \
 275   (__scanbit(*(unsigned long *)addr,(size))) : \
 276   find_first_bit(addr,size)))
 277
 278 #define find_next_bit(addr,size,off) \
 279 ((__builtin_constant_p(size) && (size) <= BITS_PER_LONG ?         \
 280   ((off) + (__scanbit((*(unsigned long *)addr) >> (off),(size)-(off)))) : \
 281         find_next_bit(addr,size,off)))
 282
 283 #define find_first_zero_bit(addr,size) \
 284 ((__builtin_constant_p(size) && (size) <= BITS_PER_LONG ? \
 285   (__scanbit(~*(unsigned long *)addr,(size))) : \
 286         find_first_zero_bit(addr,size)))
 287
 288 #define find_next_zero_bit(addr,size,off) \
 289 ((__builtin_constant_p(size) && (size) <= BITS_PER_LONG ?         \
 290   ((off)+(__scanbit(~(((*(unsigned long *)addr)) >> (off)),(size)-(off)))) : \
 291         find_next_zero_bit(addr,size,off)))
 292
 293 /*
 294  * Find string of zero bits in a bitmap. -1 when not found.
 295  */
 296 extern unsigned long
 297 find_next_zero_string(unsigned long *bitmap, long start, long nbits, int len);
 298
 299 static inline void set_bit_string(unsigned long *bitmap, unsigned long i,
 300                                   int len)
 301 {
 302         unsigned long end = i + len;
 303         while (i < end) {
 304                 __set_bit(i, bitmap);
 305                 i++;
 306         }
 307 }
 308
 309 static inline void __clear_bit_string(unsigned long *bitmap, unsigned long i,
 310                                     int len)
 311 {
 312         unsigned long end = i + len;
 313         while (i < end) {
 314                 __clear_bit(i, bitmap);
 315                 i++;
 316         }
 317 }
 318
 319 /**
 320  * ffz - find first zero in word.
 321  * @word: The word to search
 322  *
 323  * Undefined if no zero exists, so code should check against ~0UL first.
 324  */
 325 static __inline__ unsigned long ffz(unsigned long word)
 326 {
 327         __asm__("bsfq %1,%0"
 328                 :"=r" (word)
 329                 :"r" (~word));
 330         return word;
 331 }
 332
 333 /**
 334  * __ffs - find first bit in word.
 335  * @word: The word to search
 336  *
 337  * Undefined if no bit exists, so code should check against 0 first.
 338  */
 339 static __inline__ unsigned long __ffs(unsigned long word)
 340 {
 341         __asm__("bsfq %1,%0"
 342                 :"=r" (word)
 343                 :"rm" (word));
 344         return word;
 345 }
 346
 347 /*
 348  * __fls: find last bit set.
 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 {
 355         __asm__("bsrq %1,%0"
 356                 :"=r" (word)
 357                 :"rm" (word));
 358         return word;
 359 }
 360
 361 #ifdef __KERNEL__
 362
 363 #include <asm-generic/bitops/sched.h>
 364
 365 /**
 366  * ffs - find first bit set
 367  * @x: the word to search
 368  *
 369  * This is defined the same way as
 370  * the libc and compiler builtin ffs routines, therefore
 371  * differs in spirit from the above ffz (man ffs).
 372  */
 373 static __inline__ int ffs(int x)
 374 {
 375         int r;
 376
 377         __asm__("bsfl %1,%0\n\t"
 378                 "cmovzl %2,%0"
 379                 : "=r" (r) : "rm" (x), "r" (-1));
 380         return r+1;
 381 }
 382
 383 /**
 384  * fls64 - find last bit set in 64 bit word
 385  * @x: the word to search
 386  *
 387  * This is defined the same way as fls.
 388  */
 389 static __inline__ int fls64(__u64 x)
 390 {
 391         if (x == 0)
 392                 return 0;
 393         return __fls(x) + 1;
 394 }
 395
 396 /**
 397  * fls - find last bit set
 398  * @x: the word to search
 399  *
 400  * This is defined the same way as ffs.
 401  */
 402 static __inline__ int fls(int x)
 403 {
 404         int r;
 405
 406         __asm__("bsrl %1,%0\n\t"
 407                 "cmovzl %2,%0"
 408                 : "=&r" (r) : "rm" (x), "rm" (-1));
 409         return r+1;
 410 }
 411
 412 #define ARCH_HAS_FAST_MULTIPLIER 1
 413
 414 #include <asm-generic/bitops/hweight.h>
 415 #include <asm-generic/bitops/lock.h>
 416
 417 #endif /* __KERNEL__ */
 418
 419 #ifdef __KERNEL__
 420
 421 #include <asm-generic/bitops/ext2-non-atomic.h>
 422
 423 #define ext2_set_bit_atomic(lock,nr,addr) \
 424                 test_and_set_bit((nr),(unsigned long*)addr)
 425 #define ext2_clear_bit_atomic(lock,nr,addr) \
 426                 test_and_clear_bit((nr),(unsigned long*)addr)
 427
 428 #include <asm-generic/bitops/minix.h>
 429
 430 #endif /* __KERNEL__ */
 431
 432 #endif /* _X86_64_BITOPS_H */