arch/s390/include/asm/bitops.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  *    Copyright IBM Corp. 1999,2013
   4  *
   5  *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
   6  *
   7  * The description below was taken in large parts from the powerpc
   8  * bitops header file:
   9  * Within a word, bits are numbered LSB first.  Lot's of places make
  10  * this assumption by directly testing bits with (val & (1<<nr)).
  11  * This can cause confusion for large (> 1 word) bitmaps on a
  12  * big-endian system because, unlike little endian, the number of each
  13  * bit depends on the word size.
  14  *
  15  * The bitop functions are defined to work on unsigned longs, so the bits
  16  * end up numbered:
  17  *   |63..............0|127............64|191...........128|255...........192|
  18  *
  19  * We also have special functions which work with an MSB0 encoding.
  20  * The bits are numbered:
  21  *   |0..............63|64............127|128...........191|192...........255|
  22  *
  23  * The main difference is that bit 0-63 in the bit number field needs to be
  24  * reversed compared to the LSB0 encoded bit fields. This can be achieved by
  25  * XOR with 0x3f.
  26  *
  27  */
  28
  29 #ifndef _S390_BITOPS_H
  30 #define _S390_BITOPS_H
  31
  32 #ifndef _LINUX_BITOPS_H
  33 #error only <linux/bitops.h> can be included directly
  34 #endif
  35
  36 #include <linux/typecheck.h>
  37 #include <linux/compiler.h>
  38 #include <linux/types.h>
  39 #include <asm/atomic_ops.h>
  40 #include <asm/barrier.h>
  41
  42 #define __BITOPS_WORDS(bits) (((bits) + BITS_PER_LONG - 1) / BITS_PER_LONG)
  43
  44 static inline unsigned long *
  45 __bitops_word(unsigned long nr, volatile unsigned long *ptr)
  46 {
  47         unsigned long addr;
  48
  49         addr = (unsigned long)ptr + ((nr ^ (nr & (BITS_PER_LONG - 1))) >> 3);
  50         return (unsigned long *)addr;
  51 }
  52
  53 static inline unsigned char *
  54 __bitops_byte(unsigned long nr, volatile unsigned long *ptr)
  55 {
  56         return ((unsigned char *)ptr) + ((nr ^ (BITS_PER_LONG - 8)) >> 3);
  57 }
  58
  59 static __always_inline void arch_set_bit(unsigned long nr, volatile unsigned long *ptr)
  60 {
  61         unsigned long *addr = __bitops_word(nr, ptr);
  62         unsigned long mask;
  63
  64 #ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
  65         if (__builtin_constant_p(nr)) {
  66                 unsigned char *caddr = __bitops_byte(nr, ptr);
  67
  68                 asm volatile(
  69                         "oi     %0,%b1\n"
  70                         : "+Q" (*caddr)
  71                         : "i" (1 << (nr & 7))
  72                         : "cc", "memory");
  73                 return;
  74         }
  75 #endif
  76         mask = 1UL << (nr & (BITS_PER_LONG - 1));
  77         __atomic64_or(mask, (long *)addr);
  78 }
  79
  80 static __always_inline void arch_clear_bit(unsigned long nr, volatile unsigned long *ptr)
  81 {
  82         unsigned long *addr = __bitops_word(nr, ptr);
  83         unsigned long mask;
  84
  85 #ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
  86         if (__builtin_constant_p(nr)) {
  87                 unsigned char *caddr = __bitops_byte(nr, ptr);
  88
  89                 asm volatile(
  90                         "ni     %0,%b1\n"
  91                         : "+Q" (*caddr)
  92                         : "i" (~(1 << (nr & 7)))
  93                         : "cc", "memory");
  94                 return;
  95         }
  96 #endif
  97         mask = ~(1UL << (nr & (BITS_PER_LONG - 1)));
  98         __atomic64_and(mask, (long *)addr);
  99 }
 100
 101 static __always_inline void arch_change_bit(unsigned long nr,
 102                                             volatile unsigned long *ptr)
 103 {
 104         unsigned long *addr = __bitops_word(nr, ptr);
 105         unsigned long mask;
 106
 107 #ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
 108         if (__builtin_constant_p(nr)) {
 109                 unsigned char *caddr = __bitops_byte(nr, ptr);
 110
 111                 asm volatile(
 112                         "xi     %0,%b1\n"
 113                         : "+Q" (*caddr)
 114                         : "i" (1 << (nr & 7))
 115                         : "cc", "memory");
 116                 return;
 117         }
 118 #endif
 119         mask = 1UL << (nr & (BITS_PER_LONG - 1));
 120         __atomic64_xor(mask, (long *)addr);
 121 }
 122
 123 static inline bool arch_test_and_set_bit(unsigned long nr,
 124                                          volatile unsigned long *ptr)
 125 {
 126         unsigned long *addr = __bitops_word(nr, ptr);
 127         unsigned long old, mask;
 128
 129         mask = 1UL << (nr & (BITS_PER_LONG - 1));
 130         old = __atomic64_or_barrier(mask, (long *)addr);
 131         return (old & mask) != 0;
 132 }
 133
 134 static inline bool arch_test_and_clear_bit(unsigned long nr,
 135                                            volatile unsigned long *ptr)
 136 {
 137         unsigned long *addr = __bitops_word(nr, ptr);
 138         unsigned long old, mask;
 139
 140         mask = ~(1UL << (nr & (BITS_PER_LONG - 1)));
 141         old = __atomic64_and_barrier(mask, (long *)addr);
 142         return (old & ~mask) != 0;
 143 }
 144
 145 static inline bool arch_test_and_change_bit(unsigned long nr,
 146                                             volatile unsigned long *ptr)
 147 {
 148         unsigned long *addr = __bitops_word(nr, ptr);
 149         unsigned long old, mask;
 150
 151         mask = 1UL << (nr & (BITS_PER_LONG - 1));
 152         old = __atomic64_xor_barrier(mask, (long *)addr);
 153         return (old & mask) != 0;
 154 }
 155
 156 static inline void arch___set_bit(unsigned long nr, volatile unsigned long *ptr)
 157 {
 158         unsigned char *addr = __bitops_byte(nr, ptr);
 159
 160         *addr |= 1 << (nr & 7);
 161 }
 162
 163 static inline void arch___clear_bit(unsigned long nr,
 164                                     volatile unsigned long *ptr)
 165 {
 166         unsigned char *addr = __bitops_byte(nr, ptr);
 167
 168         *addr &= ~(1 << (nr & 7));
 169 }
 170
 171 static inline void arch___change_bit(unsigned long nr,
 172                                      volatile unsigned long *ptr)
 173 {
 174         unsigned char *addr = __bitops_byte(nr, ptr);
 175
 176         *addr ^= 1 << (nr & 7);
 177 }
 178
 179 static inline bool arch___test_and_set_bit(unsigned long nr,
 180                                            volatile unsigned long *ptr)
 181 {
 182         unsigned char *addr = __bitops_byte(nr, ptr);
 183         unsigned char ch;
 184
 185         ch = *addr;
 186         *addr |= 1 << (nr & 7);
 187         return (ch >> (nr & 7)) & 1;
 188 }
 189
 190 static inline bool arch___test_and_clear_bit(unsigned long nr,
 191                                              volatile unsigned long *ptr)
 192 {
 193         unsigned char *addr = __bitops_byte(nr, ptr);
 194         unsigned char ch;
 195
 196         ch = *addr;
 197         *addr &= ~(1 << (nr & 7));
 198         return (ch >> (nr & 7)) & 1;
 199 }
 200
 201 static inline bool arch___test_and_change_bit(unsigned long nr,
 202                                               volatile unsigned long *ptr)
 203 {
 204         unsigned char *addr = __bitops_byte(nr, ptr);
 205         unsigned char ch;
 206
 207         ch = *addr;
 208         *addr ^= 1 << (nr & 7);
 209         return (ch >> (nr & 7)) & 1;
 210 }
 211
 212 static inline bool arch_test_bit(unsigned long nr,
 213                                  const volatile unsigned long *ptr)
 214 {
 215         const volatile unsigned char *addr;
 216
 217         addr = ((const volatile unsigned char *)ptr);
 218         addr += (nr ^ (BITS_PER_LONG - 8)) >> 3;
 219         return (*addr >> (nr & 7)) & 1;
 220 }
 221
 222 static inline bool arch_test_and_set_bit_lock(unsigned long nr,
 223                                               volatile unsigned long *ptr)
 224 {
 225         if (arch_test_bit(nr, ptr))
 226                 return 1;
 227         return arch_test_and_set_bit(nr, ptr);
 228 }
 229
 230 static inline void arch_clear_bit_unlock(unsigned long nr,
 231                                          volatile unsigned long *ptr)
 232 {
 233         smp_mb__before_atomic();
 234         arch_clear_bit(nr, ptr);
 235 }
 236
 237 static inline void arch___clear_bit_unlock(unsigned long nr,
 238                                            volatile unsigned long *ptr)
 239 {
 240         smp_mb();
 241         arch___clear_bit(nr, ptr);
 242 }
 243
 244 #include <asm-generic/bitops/instrumented-atomic.h>
 245 #include <asm-generic/bitops/instrumented-non-atomic.h>
 246 #include <asm-generic/bitops/instrumented-lock.h>
 247
 248 /*
 249  * Functions which use MSB0 bit numbering.
 250  * The bits are numbered:
 251  *   |0..............63|64............127|128...........191|192...........255|
 252  */
 253 unsigned long find_first_bit_inv(const unsigned long *addr, unsigned long size);
 254 unsigned long find_next_bit_inv(const unsigned long *addr, unsigned long size,
 255                                 unsigned long offset);
 256
 257 #define for_each_set_bit_inv(bit, addr, size)                           \
 258         for ((bit) = find_first_bit_inv((addr), (size));                \
 259              (bit) < (size);                                            \
 260              (bit) = find_next_bit_inv((addr), (size), (bit) + 1))
 261
 262 static inline void set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
 263 {
 264         return set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 265 }
 266
 267 static inline void clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
 268 {
 269         return clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 270 }
 271
 272 static inline bool test_and_clear_bit_inv(unsigned long nr,
 273                                           volatile unsigned long *ptr)
 274 {
 275         return test_and_clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 276 }
 277
 278 static inline void __set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
 279 {
 280         return __set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 281 }
 282
 283 static inline void __clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
 284 {
 285         return __clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 286 }
 287
 288 static inline bool test_bit_inv(unsigned long nr,
 289                                 const volatile unsigned long *ptr)
 290 {
 291         return test_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 292 }
 293
 294 #ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
 295
 296 /**
 297  * __flogr - find leftmost one
 298  * @word - The word to search
 299  *
 300  * Returns the bit number of the most significant bit set,
 301  * where the most significant bit has bit number 0.
 302  * If no bit is set this function returns 64.
 303  */
 304 static inline unsigned char __flogr(unsigned long word)
 305 {
 306         if (__builtin_constant_p(word)) {
 307                 unsigned long bit = 0;
 308
 309                 if (!word)
 310                         return 64;
 311                 if (!(word & 0xffffffff00000000UL)) {
 312                         word <<= 32;
 313                         bit += 32;
 314                 }
 315                 if (!(word & 0xffff000000000000UL)) {
 316                         word <<= 16;
 317                         bit += 16;
 318                 }
 319                 if (!(word & 0xff00000000000000UL)) {
 320                         word <<= 8;
 321                         bit += 8;
 322                 }
 323                 if (!(word & 0xf000000000000000UL)) {
 324                         word <<= 4;
 325                         bit += 4;
 326                 }
 327                 if (!(word & 0xc000000000000000UL)) {
 328                         word <<= 2;
 329                         bit += 2;
 330                 }
 331                 if (!(word & 0x8000000000000000UL)) {
 332                         word <<= 1;
 333                         bit += 1;
 334                 }
 335                 return bit;
 336         } else {
 337                 register unsigned long bit asm("4") = word;
 338                 register unsigned long out asm("5");
 339
 340                 asm volatile(
 341                         "       flogr   %[bit],%[bit]\n"
 342                         : [bit] "+d" (bit), [out] "=d" (out) : : "cc");
 343                 return bit;
 344         }
 345 }
 346
 347 /**
 348  * __ffs - find first bit in word.
 349  * @word: The word to search
 350  *
 351  * Undefined if no bit exists, so code should check against 0 first.
 352  */
 353 static inline unsigned long __ffs(unsigned long word)
 354 {
 355         return __flogr(-word & word) ^ (BITS_PER_LONG - 1);
 356 }
 357
 358 /**
 359  * ffs - find first bit set
 360  * @word: the word to search
 361  *
 362  * This is defined the same way as the libc and
 363  * compiler builtin ffs routines (man ffs).
 364  */
 365 static inline int ffs(int word)
 366 {
 367         unsigned long mask = 2 * BITS_PER_LONG - 1;
 368         unsigned int val = (unsigned int)word;
 369
 370         return (1 + (__flogr(-val & val) ^ (BITS_PER_LONG - 1))) & mask;
 371 }
 372
 373 /**
 374  * __fls - find last (most-significant) set bit in a long word
 375  * @word: the word to search
 376  *
 377  * Undefined if no set bit exists, so code should check against 0 first.
 378  */
 379 static inline unsigned long __fls(unsigned long word)
 380 {
 381         return __flogr(word) ^ (BITS_PER_LONG - 1);
 382 }
 383
 384 /**
 385  * fls64 - find last set bit in a 64-bit word
 386  * @word: the word to search
 387  *
 388  * This is defined in a similar way as the libc and compiler builtin
 389  * ffsll, but returns the position of the most significant set bit.
 390  *
 391  * fls64(value) returns 0 if value is 0 or the position of the last
 392  * set bit if value is nonzero. The last (most significant) bit is
 393  * at position 64.
 394  */
 395 static inline int fls64(unsigned long word)
 396 {
 397         unsigned long mask = 2 * BITS_PER_LONG - 1;
 398
 399         return (1 + (__flogr(word) ^ (BITS_PER_LONG - 1))) & mask;
 400 }
 401
 402 /**
 403  * fls - find last (most-significant) bit set
 404  * @word: the word to search
 405  *
 406  * This is defined the same way as ffs.
 407  * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
 408  */
 409 static inline int fls(unsigned int word)
 410 {
 411         return fls64(word);
 412 }
 413
 414 #else /* CONFIG_HAVE_MARCH_Z9_109_FEATURES */
 415
 416 #include <asm-generic/bitops/__ffs.h>
 417 #include <asm-generic/bitops/ffs.h>
 418 #include <asm-generic/bitops/__fls.h>
 419 #include <asm-generic/bitops/fls.h>
 420 #include <asm-generic/bitops/fls64.h>
 421
 422 #endif /* CONFIG_HAVE_MARCH_Z9_109_FEATURES */
 423
 424 #include <asm-generic/bitops/ffz.h>
 425 #include <asm-generic/bitops/find.h>
 426 #include <asm-generic/bitops/hweight.h>
 427 #include <asm-generic/bitops/sched.h>
 428 #include <asm-generic/bitops/le.h>
 429 #include <asm-generic/bitops/ext2-atomic-setbit.h>
 430
 431 #endif /* _S390_BITOPS_H */