arch/s390/include/asm/bitops.h

   1 /*
   2  *    Copyright IBM Corp. 1999,2013
   3  *
   4  *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
   5  *
   6  * The description below was taken in large parts from the powerpc
   7  * bitops header file:
   8  * Within a word, bits are numbered LSB first.  Lot's of places make
   9  * this assumption by directly testing bits with (val & (1<<nr)).
  10  * This can cause confusion for large (> 1 word) bitmaps on a
  11  * big-endian system because, unlike little endian, the number of each
  12  * bit depends on the word size.
  13  *
  14  * The bitop functions are defined to work on unsigned longs, so the bits
  15  * end up numbered:
  16  *   |63..............0|127............64|191...........128|255...........192|
  17  *
  18  * We also have special functions which work with an MSB0 encoding.
  19  * The bits are numbered:
  20  *   |0..............63|64............127|128...........191|192...........255|
  21  *
  22  * The main difference is that bit 0-63 in the bit number field needs to be
  23  * reversed compared to the LSB0 encoded bit fields. This can be achieved by
  24  * XOR with 0x3f.
  25  *
  26  */
  27
  28 #ifndef _S390_BITOPS_H
  29 #define _S390_BITOPS_H
  30
  31 #ifndef _LINUX_BITOPS_H
  32 #error only <linux/bitops.h> can be included directly
  33 #endif
  34
  35 #include <linux/typecheck.h>
  36 #include <linux/compiler.h>
  37 #include <asm/atomic_ops.h>
  38 #include <asm/barrier.h>
  39
  40 #define __BITOPS_WORDS(bits) (((bits) + BITS_PER_LONG - 1) / BITS_PER_LONG)
  41
  42 static inline unsigned long *
  43 __bitops_word(unsigned long nr, volatile unsigned long *ptr)
  44 {
  45         unsigned long addr;
  46
  47         addr = (unsigned long)ptr + ((nr ^ (nr & (BITS_PER_LONG - 1))) >> 3);
  48         return (unsigned long *)addr;
  49 }
  50
  51 static inline unsigned char *
  52 __bitops_byte(unsigned long nr, volatile unsigned long *ptr)
  53 {
  54         return ((unsigned char *)ptr) + ((nr ^ (BITS_PER_LONG - 8)) >> 3);
  55 }
  56
  57 static inline void set_bit(unsigned long nr, volatile unsigned long *ptr)
  58 {
  59         unsigned long *addr = __bitops_word(nr, ptr);
  60         unsigned long mask;
  61
  62 #ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
  63         if (__builtin_constant_p(nr)) {
  64                 unsigned char *caddr = __bitops_byte(nr, ptr);
  65
  66                 asm volatile(
  67                         "oi     %0,%b1\n"
  68                         : "+Q" (*caddr)
  69                         : "i" (1 << (nr & 7))
  70                         : "cc", "memory");
  71                 return;
  72         }
  73 #endif
  74         mask = 1UL << (nr & (BITS_PER_LONG - 1));
  75         __atomic64_or(mask, addr);
  76 }
  77
  78 static inline void clear_bit(unsigned long nr, volatile unsigned long *ptr)
  79 {
  80         unsigned long *addr = __bitops_word(nr, ptr);
  81         unsigned long mask;
  82
  83 #ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
  84         if (__builtin_constant_p(nr)) {
  85                 unsigned char *caddr = __bitops_byte(nr, ptr);
  86
  87                 asm volatile(
  88                         "ni     %0,%b1\n"
  89                         : "+Q" (*caddr)
  90                         : "i" (~(1 << (nr & 7)))
  91                         : "cc", "memory");
  92                 return;
  93         }
  94 #endif
  95         mask = ~(1UL << (nr & (BITS_PER_LONG - 1)));
  96         __atomic64_and(mask, addr);
  97 }
  98
  99 static inline void change_bit(unsigned long nr, volatile unsigned long *ptr)
 100 {
 101         unsigned long *addr = __bitops_word(nr, ptr);
 102         unsigned long mask;
 103
 104 #ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
 105         if (__builtin_constant_p(nr)) {
 106                 unsigned char *caddr = __bitops_byte(nr, ptr);
 107
 108                 asm volatile(
 109                         "xi     %0,%b1\n"
 110                         : "+Q" (*caddr)
 111                         : "i" (1 << (nr & 7))
 112                         : "cc", "memory");
 113                 return;
 114         }
 115 #endif
 116         mask = 1UL << (nr & (BITS_PER_LONG - 1));
 117         __atomic64_xor(mask, addr);
 118 }
 119
 120 static inline int
 121 test_and_set_bit(unsigned long nr, volatile unsigned long *ptr)
 122 {
 123         unsigned long *addr = __bitops_word(nr, ptr);
 124         unsigned long old, mask;
 125
 126         mask = 1UL << (nr & (BITS_PER_LONG - 1));
 127         old = __atomic64_or_barrier(mask, addr);
 128         return (old & mask) != 0;
 129 }
 130
 131 static inline int
 132 test_and_clear_bit(unsigned long nr, volatile unsigned long *ptr)
 133 {
 134         unsigned long *addr = __bitops_word(nr, ptr);
 135         unsigned long old, mask;
 136
 137         mask = ~(1UL << (nr & (BITS_PER_LONG - 1)));
 138         old = __atomic64_and_barrier(mask, addr);
 139         return (old & ~mask) != 0;
 140 }
 141
 142 static inline int
 143 test_and_change_bit(unsigned long nr, volatile unsigned long *ptr)
 144 {
 145         unsigned long *addr = __bitops_word(nr, ptr);
 146         unsigned long old, mask;
 147
 148         mask = 1UL << (nr & (BITS_PER_LONG - 1));
 149         old = __atomic64_xor_barrier(mask, addr);
 150         return (old & mask) != 0;
 151 }
 152
 153 static inline void __set_bit(unsigned long nr, volatile unsigned long *ptr)
 154 {
 155         unsigned char *addr = __bitops_byte(nr, ptr);
 156
 157         *addr |= 1 << (nr & 7);
 158 }
 159
 160 static inline void
 161 __clear_bit(unsigned long nr, volatile unsigned long *ptr)
 162 {
 163         unsigned char *addr = __bitops_byte(nr, ptr);
 164
 165         *addr &= ~(1 << (nr & 7));
 166 }
 167
 168 static inline void __change_bit(unsigned long nr, volatile unsigned long *ptr)
 169 {
 170         unsigned char *addr = __bitops_byte(nr, ptr);
 171
 172         *addr ^= 1 << (nr & 7);
 173 }
 174
 175 static inline int
 176 __test_and_set_bit(unsigned long nr, volatile unsigned long *ptr)
 177 {
 178         unsigned char *addr = __bitops_byte(nr, ptr);
 179         unsigned char ch;
 180
 181         ch = *addr;
 182         *addr |= 1 << (nr & 7);
 183         return (ch >> (nr & 7)) & 1;
 184 }
 185
 186 static inline int
 187 __test_and_clear_bit(unsigned long nr, volatile unsigned long *ptr)
 188 {
 189         unsigned char *addr = __bitops_byte(nr, ptr);
 190         unsigned char ch;
 191
 192         ch = *addr;
 193         *addr &= ~(1 << (nr & 7));
 194         return (ch >> (nr & 7)) & 1;
 195 }
 196
 197 static inline int
 198 __test_and_change_bit(unsigned long nr, volatile unsigned long *ptr)
 199 {
 200         unsigned char *addr = __bitops_byte(nr, ptr);
 201         unsigned char ch;
 202
 203         ch = *addr;
 204         *addr ^= 1 << (nr & 7);
 205         return (ch >> (nr & 7)) & 1;
 206 }
 207
 208 static inline int test_bit(unsigned long nr, const volatile unsigned long *ptr)
 209 {
 210         const volatile unsigned char *addr;
 211
 212         addr = ((const volatile unsigned char *)ptr);
 213         addr += (nr ^ (BITS_PER_LONG - 8)) >> 3;
 214         return (*addr >> (nr & 7)) & 1;
 215 }
 216
 217 static inline int test_and_set_bit_lock(unsigned long nr,
 218                                         volatile unsigned long *ptr)
 219 {
 220         if (test_bit(nr, ptr))
 221                 return 1;
 222         return test_and_set_bit(nr, ptr);
 223 }
 224
 225 static inline void clear_bit_unlock(unsigned long nr,
 226                                     volatile unsigned long *ptr)
 227 {
 228         smp_mb__before_atomic();
 229         clear_bit(nr, ptr);
 230 }
 231
 232 static inline void __clear_bit_unlock(unsigned long nr,
 233                                       volatile unsigned long *ptr)
 234 {
 235         smp_mb();
 236         __clear_bit(nr, ptr);
 237 }
 238
 239 /*
 240  * Functions which use MSB0 bit numbering.
 241  * The bits are numbered:
 242  *   |0..............63|64............127|128...........191|192...........255|
 243  */
 244 unsigned long find_first_bit_inv(const unsigned long *addr, unsigned long size);
 245 unsigned long find_next_bit_inv(const unsigned long *addr, unsigned long size,
 246                                 unsigned long offset);
 247
 248 #define for_each_set_bit_inv(bit, addr, size)                           \
 249         for ((bit) = find_first_bit_inv((addr), (size));                \
 250              (bit) < (size);                                            \
 251              (bit) = find_next_bit_inv((addr), (size), (bit) + 1))
 252
 253 static inline void set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
 254 {
 255         return set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 256 }
 257
 258 static inline void clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
 259 {
 260         return clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 261 }
 262
 263 static inline void __set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
 264 {
 265         return __set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 266 }
 267
 268 static inline void __clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
 269 {
 270         return __clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 271 }
 272
 273 static inline int test_bit_inv(unsigned long nr,
 274                                const volatile unsigned long *ptr)
 275 {
 276         return test_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 277 }
 278
 279 #ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
 280
 281 /**
 282  * __flogr - find leftmost one
 283  * @word - The word to search
 284  *
 285  * Returns the bit number of the most significant bit set,
 286  * where the most significant bit has bit number 0.
 287  * If no bit is set this function returns 64.
 288  */
 289 static inline unsigned char __flogr(unsigned long word)
 290 {
 291         if (__builtin_constant_p(word)) {
 292                 unsigned long bit = 0;
 293
 294                 if (!word)
 295                         return 64;
 296                 if (!(word & 0xffffffff00000000UL)) {
 297                         word <<= 32;
 298                         bit += 32;
 299                 }
 300                 if (!(word & 0xffff000000000000UL)) {
 301                         word <<= 16;
 302                         bit += 16;
 303                 }
 304                 if (!(word & 0xff00000000000000UL)) {
 305                         word <<= 8;
 306                         bit += 8;
 307                 }
 308                 if (!(word & 0xf000000000000000UL)) {
 309                         word <<= 4;
 310                         bit += 4;
 311                 }
 312                 if (!(word & 0xc000000000000000UL)) {
 313                         word <<= 2;
 314                         bit += 2;
 315                 }
 316                 if (!(word & 0x8000000000000000UL)) {
 317                         word <<= 1;
 318                         bit += 1;
 319                 }
 320                 return bit;
 321         } else {
 322                 register unsigned long bit asm("4") = word;
 323                 register unsigned long out asm("5");
 324
 325                 asm volatile(
 326                         "       flogr   %[bit],%[bit]\n"
 327                         : [bit] "+d" (bit), [out] "=d" (out) : : "cc");
 328                 return bit;
 329         }
 330 }
 331
 332 /**
 333  * __ffs - find first bit in word.
 334  * @word: The word to search
 335  *
 336  * Undefined if no bit exists, so code should check against 0 first.
 337  */
 338 static inline unsigned long __ffs(unsigned long word)
 339 {
 340         return __flogr(-word & word) ^ (BITS_PER_LONG - 1);
 341 }
 342
 343 /**
 344  * ffs - find first bit set
 345  * @word: the word to search
 346  *
 347  * This is defined the same way as the libc and
 348  * compiler builtin ffs routines (man ffs).
 349  */
 350 static inline int ffs(int word)
 351 {
 352         unsigned long mask = 2 * BITS_PER_LONG - 1;
 353         unsigned int val = (unsigned int)word;
 354
 355         return (1 + (__flogr(-val & val) ^ (BITS_PER_LONG - 1))) & mask;
 356 }
 357
 358 /**
 359  * __fls - find last (most-significant) set bit in a long word
 360  * @word: the word to search
 361  *
 362  * Undefined if no set bit exists, so code should check against 0 first.
 363  */
 364 static inline unsigned long __fls(unsigned long word)
 365 {
 366         return __flogr(word) ^ (BITS_PER_LONG - 1);
 367 }
 368
 369 /**
 370  * fls64 - find last set bit in a 64-bit word
 371  * @word: the word to search
 372  *
 373  * This is defined in a similar way as the libc and compiler builtin
 374  * ffsll, but returns the position of the most significant set bit.
 375  *
 376  * fls64(value) returns 0 if value is 0 or the position of the last
 377  * set bit if value is nonzero. The last (most significant) bit is
 378  * at position 64.
 379  */
 380 static inline int fls64(unsigned long word)
 381 {
 382         unsigned long mask = 2 * BITS_PER_LONG - 1;
 383
 384         return (1 + (__flogr(word) ^ (BITS_PER_LONG - 1))) & mask;
 385 }
 386
 387 /**
 388  * fls - find last (most-significant) bit set
 389  * @word: the word to search
 390  *
 391  * This is defined the same way as ffs.
 392  * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
 393  */
 394 static inline int fls(int word)
 395 {
 396         return fls64((unsigned int)word);
 397 }
 398
 399 #else /* CONFIG_HAVE_MARCH_Z9_109_FEATURES */
 400
 401 #include <asm-generic/bitops/__ffs.h>
 402 #include <asm-generic/bitops/ffs.h>
 403 #include <asm-generic/bitops/__fls.h>
 404 #include <asm-generic/bitops/fls.h>
 405 #include <asm-generic/bitops/fls64.h>
 406
 407 #endif /* CONFIG_HAVE_MARCH_Z9_109_FEATURES */
 408
 409 #include <asm-generic/bitops/ffz.h>
 410 #include <asm-generic/bitops/find.h>
 411 #include <asm-generic/bitops/hweight.h>
 412 #include <asm-generic/bitops/sched.h>
 413 #include <asm-generic/bitops/le.h>
 414 #include <asm-generic/bitops/ext2-atomic-setbit.h>
 415
 416 #endif /* _S390_BITOPS_H */