include/asm-mips/bitops.h

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (c) 1994 - 1997, 99, 2000, 06, 07  Ralf Baechle (ralf@linux-mips.org)
   7  * Copyright (c) 1999, 2000  Silicon Graphics, Inc.
   8  */
   9 #ifndef _ASM_BITOPS_H
  10 #define _ASM_BITOPS_H
  11
  12 #include <linux/compiler.h>
  13 #include <linux/irqflags.h>
  14 #include <linux/types.h>
  15 #include <asm/barrier.h>
  16 #include <asm/bug.h>
  17 #include <asm/byteorder.h>              /* sigh ... */
  18 #include <asm/cpu-features.h>
  19 #include <asm/sgidefs.h>
  20 #include <asm/war.h>
  21
  22 #if (_MIPS_SZLONG == 32)
  23 #define SZLONG_LOG 5
  24 #define SZLONG_MASK 31UL
  25 #define __LL            "ll     "
  26 #define __SC            "sc     "
  27 #define __INS           "ins    "
  28 #define __EXT           "ext    "
  29 #elif (_MIPS_SZLONG == 64)
  30 #define SZLONG_LOG 6
  31 #define SZLONG_MASK 63UL
  32 #define __LL            "lld    "
  33 #define __SC            "scd    "
  34 #define __INS           "dins    "
  35 #define __EXT           "dext    "
  36 #endif
  37
  38 /*
  39  * clear_bit() doesn't provide any barrier for the compiler.
  40  */
  41 #define smp_mb__before_clear_bit()      smp_mb()
  42 #define smp_mb__after_clear_bit()       smp_mb()
  43
  44 /*
  45  * set_bit - Atomically set a bit in memory
  46  * @nr: the bit to set
  47  * @addr: the address to start counting from
  48  *
  49  * This function is atomic and may not be reordered.  See __set_bit()
  50  * if you do not require the atomic guarantees.
  51  * Note that @nr may be almost arbitrarily large; this function is not
  52  * restricted to acting on a single-word quantity.
  53  */
  54 static inline void set_bit(unsigned long nr, volatile unsigned long *addr)
  55 {
  56         unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
  57         unsigned short bit = nr & SZLONG_MASK;
  58         unsigned long temp;
  59
  60         if (cpu_has_llsc && R10000_LLSC_WAR) {
  61                 __asm__ __volatile__(
  62                 "       .set    mips3                                   \n"
  63                 "1:     " __LL "%0, %1                  # set_bit       \n"
  64                 "       or      %0, %2                                  \n"
  65                 "       " __SC  "%0, %1                                 \n"
  66                 "       beqzl   %0, 1b                                  \n"
  67                 "       .set    mips0                                   \n"
  68                 : "=&r" (temp), "=m" (*m)
  69                 : "ir" (1UL << bit), "m" (*m));
  70 #ifdef CONFIG_CPU_MIPSR2
  71         } else if (__builtin_constant_p(bit)) {
  72                 __asm__ __volatile__(
  73                 "1:     " __LL "%0, %1                  # set_bit       \n"
  74                 "       " __INS "%0, %4, %2, 1                          \n"
  75                 "       " __SC "%0, %1                                  \n"
  76                 "       beqz    %0, 2f                                  \n"
  77                 "       .subsection 2                                   \n"
  78                 "2:     b       1b                                      \n"
  79                 "       .previous                                       \n"
  80                 : "=&r" (temp), "=m" (*m)
  81                 : "ir" (bit), "m" (*m), "r" (~0));
  82 #endif /* CONFIG_CPU_MIPSR2 */
  83         } else if (cpu_has_llsc) {
  84                 __asm__ __volatile__(
  85                 "       .set    mips3                                   \n"
  86                 "1:     " __LL "%0, %1                  # set_bit       \n"
  87                 "       or      %0, %2                                  \n"
  88                 "       " __SC  "%0, %1                                 \n"
  89                 "       beqz    %0, 2f                                  \n"
  90                 "       .subsection 2                                   \n"
  91                 "2:     b       1b                                      \n"
  92                 "       .previous                                       \n"
  93                 "       .set    mips0                                   \n"
  94                 : "=&r" (temp), "=m" (*m)
  95                 : "ir" (1UL << bit), "m" (*m));
  96         } else {
  97                 volatile unsigned long *a = addr;
  98                 unsigned long mask;
  99                 unsigned long flags;
 100
 101                 a += nr >> SZLONG_LOG;
 102                 mask = 1UL << bit;
 103                 raw_local_irq_save(flags);
 104                 *a |= mask;
 105                 raw_local_irq_restore(flags);
 106         }
 107 }
 108
 109 /*
 110  * clear_bit - Clears a bit in memory
 111  * @nr: Bit to clear
 112  * @addr: Address to start counting from
 113  *
 114  * clear_bit() is atomic and may not be reordered.  However, it does
 115  * not contain a memory barrier, so if it is used for locking purposes,
 116  * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
 117  * in order to ensure changes are visible on other processors.
 118  */
 119 static inline void clear_bit(unsigned long nr, volatile unsigned long *addr)
 120 {
 121         unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
 122         unsigned short bit = nr & SZLONG_MASK;
 123         unsigned long temp;
 124
 125         if (cpu_has_llsc && R10000_LLSC_WAR) {
 126                 __asm__ __volatile__(
 127                 "       .set    mips3                                   \n"
 128                 "1:     " __LL "%0, %1                  # clear_bit     \n"
 129                 "       and     %0, %2                                  \n"
 130                 "       " __SC "%0, %1                                  \n"
 131                 "       beqzl   %0, 1b                                  \n"
 132                 "       .set    mips0                                   \n"
 133                 : "=&r" (temp), "=m" (*m)
 134                 : "ir" (~(1UL << bit)), "m" (*m));
 135 #ifdef CONFIG_CPU_MIPSR2
 136         } else if (__builtin_constant_p(bit)) {
 137                 __asm__ __volatile__(
 138                 "1:     " __LL "%0, %1                  # clear_bit     \n"
 139                 "       " __INS "%0, $0, %2, 1                          \n"
 140                 "       " __SC "%0, %1                                  \n"
 141                 "       beqz    %0, 2f                                  \n"
 142                 "       .subsection 2                                   \n"
 143                 "2:     b       1b                                      \n"
 144                 "       .previous                                       \n"
 145                 : "=&r" (temp), "=m" (*m)
 146                 : "ir" (bit), "m" (*m));
 147 #endif /* CONFIG_CPU_MIPSR2 */
 148         } else if (cpu_has_llsc) {
 149                 __asm__ __volatile__(
 150                 "       .set    mips3                                   \n"
 151                 "1:     " __LL "%0, %1                  # clear_bit     \n"
 152                 "       and     %0, %2                                  \n"
 153                 "       " __SC "%0, %1                                  \n"
 154                 "       beqz    %0, 2f                                  \n"
 155                 "       .subsection 2                                   \n"
 156                 "2:     b       1b                                      \n"
 157                 "       .previous                                       \n"
 158                 "       .set    mips0                                   \n"
 159                 : "=&r" (temp), "=m" (*m)
 160                 : "ir" (~(1UL << bit)), "m" (*m));
 161         } else {
 162                 volatile unsigned long *a = addr;
 163                 unsigned long mask;
 164                 unsigned long flags;
 165
 166                 a += nr >> SZLONG_LOG;
 167                 mask = 1UL << bit;
 168                 raw_local_irq_save(flags);
 169                 *a &= ~mask;
 170                 raw_local_irq_restore(flags);
 171         }
 172 }
 173
 174 /*
 175  * change_bit - Toggle a bit in memory
 176  * @nr: Bit to change
 177  * @addr: Address to start counting from
 178  *
 179  * change_bit() is atomic and may not be reordered.
 180  * Note that @nr may be almost arbitrarily large; this function is not
 181  * restricted to acting on a single-word quantity.
 182  */
 183 static inline void change_bit(unsigned long nr, volatile unsigned long *addr)
 184 {
 185         unsigned short bit = nr & SZLONG_MASK;
 186
 187         if (cpu_has_llsc && R10000_LLSC_WAR) {
 188                 unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
 189                 unsigned long temp;
 190
 191                 __asm__ __volatile__(
 192                 "       .set    mips3                           \n"
 193                 "1:     " __LL "%0, %1          # change_bit    \n"
 194                 "       xor     %0, %2                          \n"
 195                 "       " __SC  "%0, %1                         \n"
 196                 "       beqzl   %0, 1b                          \n"
 197                 "       .set    mips0                           \n"
 198                 : "=&r" (temp), "=m" (*m)
 199                 : "ir" (1UL << bit), "m" (*m));
 200         } else if (cpu_has_llsc) {
 201                 unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
 202                 unsigned long temp;
 203
 204                 __asm__ __volatile__(
 205                 "       .set    mips3                           \n"
 206                 "1:     " __LL "%0, %1          # change_bit    \n"
 207                 "       xor     %0, %2                          \n"
 208                 "       " __SC  "%0, %1                         \n"
 209                 "       beqz    %0, 2f                          \n"
 210                 "       .subsection 2                           \n"
 211                 "2:     b       1b                              \n"
 212                 "       .previous                               \n"
 213                 "       .set    mips0                           \n"
 214                 : "=&r" (temp), "=m" (*m)
 215                 : "ir" (1UL << bit), "m" (*m));
 216         } else {
 217                 volatile unsigned long *a = addr;
 218                 unsigned long mask;
 219                 unsigned long flags;
 220
 221                 a += nr >> SZLONG_LOG;
 222                 mask = 1UL << bit;
 223                 raw_local_irq_save(flags);
 224                 *a ^= mask;
 225                 raw_local_irq_restore(flags);
 226         }
 227 }
 228
 229 /*
 230  * test_and_set_bit - Set a bit and return its old value
 231  * @nr: Bit to set
 232  * @addr: Address to count from
 233  *
 234  * This operation is atomic and cannot be reordered.
 235  * It also implies a memory barrier.
 236  */
 237 static inline int test_and_set_bit(unsigned long nr,
 238         volatile unsigned long *addr)
 239 {
 240         unsigned short bit = nr & SZLONG_MASK;
 241
 242         if (cpu_has_llsc && R10000_LLSC_WAR) {
 243                 unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
 244                 unsigned long temp, res;
 245
 246                 __asm__ __volatile__(
 247                 "       .set    mips3                                   \n"
 248                 "1:     " __LL "%0, %1          # test_and_set_bit      \n"
 249                 "       or      %2, %0, %3                              \n"
 250                 "       " __SC  "%2, %1                                 \n"
 251                 "       beqzl   %2, 1b                                  \n"
 252                 "       and     %2, %0, %3                              \n"
 253                 "       .set    mips0                                   \n"
 254                 : "=&r" (temp), "=m" (*m), "=&r" (res)
 255                 : "r" (1UL << bit), "m" (*m)
 256                 : "memory");
 257
 258                 return res != 0;
 259         } else if (cpu_has_llsc) {
 260                 unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
 261                 unsigned long temp, res;
 262
 263                 __asm__ __volatile__(
 264                 "       .set    push                                    \n"
 265                 "       .set    noreorder                               \n"
 266                 "       .set    mips3                                   \n"
 267                 "1:     " __LL "%0, %1          # test_and_set_bit      \n"
 268                 "       or      %2, %0, %3                              \n"
 269                 "       " __SC  "%2, %1                                 \n"
 270                 "       beqz    %2, 2f                                  \n"
 271                 "        and    %2, %0, %3                              \n"
 272                 "       .subsection 2                                   \n"
 273                 "2:     b       1b                                      \n"
 274                 "        nop                                            \n"
 275                 "       .previous                                       \n"
 276                 "       .set    pop                                     \n"
 277                 : "=&r" (temp), "=m" (*m), "=&r" (res)
 278                 : "r" (1UL << bit), "m" (*m)
 279                 : "memory");
 280
 281                 return res != 0;
 282         } else {
 283                 volatile unsigned long *a = addr;
 284                 unsigned long mask;
 285                 int retval;
 286                 unsigned long flags;
 287
 288                 a += nr >> SZLONG_LOG;
 289                 mask = 1UL << bit;
 290                 raw_local_irq_save(flags);
 291                 retval = (mask & *a) != 0;
 292                 *a |= mask;
 293                 raw_local_irq_restore(flags);
 294
 295                 return retval;
 296         }
 297
 298         smp_mb();
 299 }
 300
 301 /*
 302  * test_and_clear_bit - Clear a bit and return its old value
 303  * @nr: Bit to clear
 304  * @addr: Address to count from
 305  *
 306  * This operation is atomic and cannot be reordered.
 307  * It also implies a memory barrier.
 308  */
 309 static inline int test_and_clear_bit(unsigned long nr,
 310         volatile unsigned long *addr)
 311 {
 312         unsigned short bit = nr & SZLONG_MASK;
 313
 314         if (cpu_has_llsc && R10000_LLSC_WAR) {
 315                 unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
 316                 unsigned long temp, res;
 317
 318                 __asm__ __volatile__(
 319                 "       .set    mips3                                   \n"
 320                 "1:     " __LL  "%0, %1         # test_and_clear_bit    \n"
 321                 "       or      %2, %0, %3                              \n"
 322                 "       xor     %2, %3                                  \n"
 323                 "       " __SC  "%2, %1                                 \n"
 324                 "       beqzl   %2, 1b                                  \n"
 325                 "       and     %2, %0, %3                              \n"
 326                 "       .set    mips0                                   \n"
 327                 : "=&r" (temp), "=m" (*m), "=&r" (res)
 328                 : "r" (1UL << bit), "m" (*m)
 329                 : "memory");
 330
 331                 return res != 0;
 332 #ifdef CONFIG_CPU_MIPSR2
 333         } else if (__builtin_constant_p(nr)) {
 334                 unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
 335                 unsigned long temp, res;
 336
 337                 __asm__ __volatile__(
 338                 "1:     " __LL  "%0, %1         # test_and_clear_bit    \n"
 339                 "       " __EXT "%2, %0, %3, 1                          \n"
 340                 "       " __INS "%0, $0, %3, 1                          \n"
 341                 "       " __SC  "%0, %1                                 \n"
 342                 "       beqz    %0, 2f                                  \n"
 343                 "       .subsection 2                                   \n"
 344                 "2:     b       1b                                      \n"
 345                 "       .previous                                       \n"
 346                 : "=&r" (temp), "=m" (*m), "=&r" (res)
 347                 : "ri" (bit), "m" (*m)
 348                 : "memory");
 349
 350                 return res;
 351 #endif
 352         } else if (cpu_has_llsc) {
 353                 unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
 354                 unsigned long temp, res;
 355
 356                 __asm__ __volatile__(
 357                 "       .set    push                                    \n"
 358                 "       .set    noreorder                               \n"
 359                 "       .set    mips3                                   \n"
 360                 "1:     " __LL  "%0, %1         # test_and_clear_bit    \n"
 361                 "       or      %2, %0, %3                              \n"
 362                 "       xor     %2, %3                                  \n"
 363                 "       " __SC  "%2, %1                                 \n"
 364                 "       beqz    %2, 2f                                  \n"
 365                 "        and    %2, %0, %3                              \n"
 366                 "       .subsection 2                                   \n"
 367                 "2:     b       1b                                      \n"
 368                 "        nop                                            \n"
 369                 "       .previous                                       \n"
 370                 "       .set    pop                                     \n"
 371                 : "=&r" (temp), "=m" (*m), "=&r" (res)
 372                 : "r" (1UL << bit), "m" (*m)
 373                 : "memory");
 374
 375                 return res != 0;
 376         } else {
 377                 volatile unsigned long *a = addr;
 378                 unsigned long mask;
 379                 int retval;
 380                 unsigned long flags;
 381
 382                 a += nr >> SZLONG_LOG;
 383                 mask = 1UL << bit;
 384                 raw_local_irq_save(flags);
 385                 retval = (mask & *a) != 0;
 386                 *a &= ~mask;
 387                 raw_local_irq_restore(flags);
 388
 389                 return retval;
 390         }
 391
 392         smp_mb();
 393 }
 394
 395 /*
 396  * test_and_change_bit - Change a bit and return its old value
 397  * @nr: Bit to change
 398  * @addr: Address to count from
 399  *
 400  * This operation is atomic and cannot be reordered.
 401  * It also implies a memory barrier.
 402  */
 403 static inline int test_and_change_bit(unsigned long nr,
 404         volatile unsigned long *addr)
 405 {
 406         unsigned short bit = nr & SZLONG_MASK;
 407
 408         if (cpu_has_llsc && R10000_LLSC_WAR) {
 409                 unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
 410                 unsigned long temp, res;
 411
 412                 __asm__ __volatile__(
 413                 "       .set    mips3                                   \n"
 414                 "1:     " __LL  "%0, %1         # test_and_change_bit   \n"
 415                 "       xor     %2, %0, %3                              \n"
 416                 "       " __SC  "%2, %1                                 \n"
 417                 "       beqzl   %2, 1b                                  \n"
 418                 "       and     %2, %0, %3                              \n"
 419                 "       .set    mips0                                   \n"
 420                 : "=&r" (temp), "=m" (*m), "=&r" (res)
 421                 : "r" (1UL << bit), "m" (*m)
 422                 : "memory");
 423
 424                 return res != 0;
 425         } else if (cpu_has_llsc) {
 426                 unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
 427                 unsigned long temp, res;
 428
 429                 __asm__ __volatile__(
 430                 "       .set    push                                    \n"
 431                 "       .set    noreorder                               \n"
 432                 "       .set    mips3                                   \n"
 433                 "1:     " __LL  "%0, %1         # test_and_change_bit   \n"
 434                 "       xor     %2, %0, %3                              \n"
 435                 "       " __SC  "\t%2, %1                               \n"
 436                 "       beqz    %2, 2f                                  \n"
 437                 "        and    %2, %0, %3                              \n"
 438                 "       .subsection 2                                   \n"
 439                 "2:     b       1b                                      \n"
 440                 "        nop                                            \n"
 441                 "       .previous                                       \n"
 442                 "       .set    pop                                     \n"
 443                 : "=&r" (temp), "=m" (*m), "=&r" (res)
 444                 : "r" (1UL << bit), "m" (*m)
 445                 : "memory");
 446
 447                 return res != 0;
 448         } else {
 449                 volatile unsigned long *a = addr;
 450                 unsigned long mask, retval;
 451                 unsigned long flags;
 452
 453                 a += nr >> SZLONG_LOG;
 454                 mask = 1UL << bit;
 455                 raw_local_irq_save(flags);
 456                 retval = (mask & *a) != 0;
 457                 *a ^= mask;
 458                 raw_local_irq_restore(flags);
 459
 460                 return retval;
 461         }
 462
 463         smp_mb();
 464 }
 465
 466 #include <asm-generic/bitops/non-atomic.h>
 467
 468 /*
 469  * Return the bit position (0..63) of the most significant 1 bit in a word
 470  * Returns -1 if no 1 bit exists
 471  */
 472 static inline int __ilog2(unsigned long x)
 473 {
 474         int lz;
 475
 476         if (sizeof(x) == 4) {
 477                 __asm__ (
 478                 "       .set    push                                    \n"
 479                 "       .set    mips32                                  \n"
 480                 "       clz     %0, %1                                  \n"
 481                 "       .set    pop                                     \n"
 482                 : "=r" (lz)
 483                 : "r" (x));
 484
 485                 return 31 - lz;
 486         }
 487
 488         BUG_ON(sizeof(x) != 8);
 489
 490         __asm__ (
 491         "       .set    push                                            \n"
 492         "       .set    mips64                                          \n"
 493         "       dclz    %0, %1                                          \n"
 494         "       .set    pop                                             \n"
 495         : "=r" (lz)
 496         : "r" (x));
 497
 498         return 63 - lz;
 499 }
 500
 501 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
 502
 503 /*
 504  * __ffs - find first bit in word.
 505  * @word: The word to search
 506  *
 507  * Returns 0..SZLONG-1
 508  * Undefined if no bit exists, so code should check against 0 first.
 509  */
 510 static inline unsigned long __ffs(unsigned long word)
 511 {
 512         return __ilog2(word & -word);
 513 }
 514
 515 /*
 516  * fls - find last bit set.
 517  * @word: The word to search
 518  *
 519  * This is defined the same way as ffs.
 520  * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
 521  */
 522 static inline int fls(int word)
 523 {
 524         __asm__ ("clz %0, %1" : "=r" (word) : "r" (word));
 525
 526         return 32 - word;
 527 }
 528
 529 #if defined(CONFIG_64BIT) && defined(CONFIG_CPU_MIPS64)
 530 static inline int fls64(__u64 word)
 531 {
 532         __asm__ ("dclz %0, %1" : "=r" (word) : "r" (word));
 533
 534         return 64 - word;
 535 }
 536 #else
 537 #include <asm-generic/bitops/fls64.h>
 538 #endif
 539
 540 /*
 541  * ffs - find first bit set.
 542  * @word: The word to search
 543  *
 544  * This is defined the same way as
 545  * the libc and compiler builtin ffs routines, therefore
 546  * differs in spirit from the above ffz (man ffs).
 547  */
 548 static inline int ffs(int word)
 549 {
 550         if (!word)
 551                 return 0;
 552
 553         return fls(word & -word);
 554 }
 555
 556 #else
 557
 558 #include <asm-generic/bitops/__ffs.h>
 559 #include <asm-generic/bitops/ffs.h>
 560 #include <asm-generic/bitops/fls.h>
 561 #include <asm-generic/bitops/fls64.h>
 562
 563 #endif /*defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64) */
 564
 565 #include <asm-generic/bitops/ffz.h>
 566 #include <asm-generic/bitops/find.h>
 567
 568 #ifdef __KERNEL__
 569
 570 #include <asm-generic/bitops/sched.h>
 571 #include <asm-generic/bitops/hweight.h>
 572 #include <asm-generic/bitops/ext2-non-atomic.h>
 573 #include <asm-generic/bitops/ext2-atomic.h>
 574 #include <asm-generic/bitops/minix.h>
 575
 576 #endif /* __KERNEL__ */
 577
 578 #endif /* _ASM_BITOPS_H */