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 for an
  15  * s390x system the bits end up numbered:
  16  *   |63..............0|127............64|191...........128|255...........192|
  17  * and on s390:
  18  *   |31.....0|63....32|95....64|127...96|159..128|191..160|223..192|255..224|
  19  *
  20  * There are a few little-endian macros used mostly for filesystem
  21  * bitmaps, these work on similar bit arrays layouts, but
  22  * byte-oriented:
  23  *   |7...0|15...8|23...16|31...24|39...32|47...40|55...48|63...56|
  24  *
  25  * The main difference is that bit 3-5 (64b) or 3-4 (32b) in the bit
  26  * number field needs to be reversed compared to the big-endian bit
  27  * fields. This can be achieved by XOR with 0x38 (64b) or 0x18 (32b).
  28  *
  29  * We also have special functions which work with an MSB0 encoding:
  30  * on an s390x system the bits are numbered:
  31  *   |0..............63|64............127|128...........191|192...........255|
  32  * and on s390:
  33  *   |0.....31|32....63|64....95|96...127|128..159|160..191|192..223|224..255|
  34  *
  35  * The main difference is that bit 0-63 (64b) or 0-31 (32b) in the bit
  36  * number field needs to be reversed compared to the LSB0 encoded bit
  37  * fields. This can be achieved by XOR with 0x3f (64b) or 0x1f (32b).
  38  *
  39  */
  40
  41 #ifndef _S390_BITOPS_H
  42 #define _S390_BITOPS_H
  43
  44 #ifndef _LINUX_BITOPS_H
  45 #error only <linux/bitops.h> can be included directly
  46 #endif
  47
  48 #include <linux/typecheck.h>
  49 #include <linux/compiler.h>
  50 #include <asm/barrier.h>
  51
  52 #define __BITOPS_NO_BARRIER     "\n"
  53
  54 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
  55
  56 #define __BITOPS_OR             "laog"
  57 #define __BITOPS_AND            "lang"
  58 #define __BITOPS_XOR            "laxg"
  59 #define __BITOPS_BARRIER        "bcr    14,0\n"
  60
  61 #define __BITOPS_LOOP(__addr, __val, __op_string, __barrier)    \
  62 ({                                                              \
  63         unsigned long __old;                                    \
  64                                                                 \
  65         typecheck(unsigned long *, (__addr));                   \
  66         asm volatile(                                           \
  67                 __barrier                                       \
  68                 __op_string "   %0,%2,%1\n"                     \
  69                 __barrier                                       \
  70                 : "=d" (__old), "+Q" (*(__addr))                \
  71                 : "d" (__val)                                   \
  72                 : "cc", "memory");                              \
  73         __old;                                                  \
  74 })
  75
  76 #else /* CONFIG_HAVE_MARCH_Z196_FEATURES */
  77
  78 #define __BITOPS_OR             "ogr"
  79 #define __BITOPS_AND            "ngr"
  80 #define __BITOPS_XOR            "xgr"
  81 #define __BITOPS_BARRIER        "\n"
  82
  83 #define __BITOPS_LOOP(__addr, __val, __op_string, __barrier)    \
  84 ({                                                              \
  85         unsigned long __old, __new;                             \
  86                                                                 \
  87         typecheck(unsigned long *, (__addr));                   \
  88         asm volatile(                                           \
  89                 "       lg      %0,%2\n"                        \
  90                 "0:     lgr     %1,%0\n"                        \
  91                 __op_string "   %1,%3\n"                        \
  92                 "       csg     %0,%1,%2\n"                     \
  93                 "       jl      0b"                             \
  94                 : "=&d" (__old), "=&d" (__new), "+Q" (*(__addr))\
  95                 : "d" (__val)                                   \
  96                 : "cc", "memory");                              \
  97         __old;                                                  \
  98 })
  99
 100 #endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */
 101
 102 #define __BITOPS_WORDS(bits) (((bits) + BITS_PER_LONG - 1) / BITS_PER_LONG)
 103
 104 static inline unsigned long *
 105 __bitops_word(unsigned long nr, volatile unsigned long *ptr)
 106 {
 107         unsigned long addr;
 108
 109         addr = (unsigned long)ptr + ((nr ^ (nr & (BITS_PER_LONG - 1))) >> 3);
 110         return (unsigned long *)addr;
 111 }
 112
 113 static inline unsigned char *
 114 __bitops_byte(unsigned long nr, volatile unsigned long *ptr)
 115 {
 116         return ((unsigned char *)ptr) + ((nr ^ (BITS_PER_LONG - 8)) >> 3);
 117 }
 118
 119 static inline void set_bit(unsigned long nr, volatile unsigned long *ptr)
 120 {
 121         unsigned long *addr = __bitops_word(nr, ptr);
 122         unsigned long mask;
 123
 124 #ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
 125         if (__builtin_constant_p(nr)) {
 126                 unsigned char *caddr = __bitops_byte(nr, ptr);
 127
 128                 asm volatile(
 129                         "oi     %0,%b1\n"
 130                         : "+Q" (*caddr)
 131                         : "i" (1 << (nr & 7))
 132                         : "cc", "memory");
 133                 return;
 134         }
 135 #endif
 136         mask = 1UL << (nr & (BITS_PER_LONG - 1));
 137         __BITOPS_LOOP(addr, mask, __BITOPS_OR, __BITOPS_NO_BARRIER);
 138 }
 139
 140 static inline void clear_bit(unsigned long nr, volatile unsigned long *ptr)
 141 {
 142         unsigned long *addr = __bitops_word(nr, ptr);
 143         unsigned long mask;
 144
 145 #ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
 146         if (__builtin_constant_p(nr)) {
 147                 unsigned char *caddr = __bitops_byte(nr, ptr);
 148
 149                 asm volatile(
 150                         "ni     %0,%b1\n"
 151                         : "+Q" (*caddr)
 152                         : "i" (~(1 << (nr & 7)))
 153                         : "cc", "memory");
 154                 return;
 155         }
 156 #endif
 157         mask = ~(1UL << (nr & (BITS_PER_LONG - 1)));
 158         __BITOPS_LOOP(addr, mask, __BITOPS_AND, __BITOPS_NO_BARRIER);
 159 }
 160
 161 static inline void change_bit(unsigned long nr, volatile unsigned long *ptr)
 162 {
 163         unsigned long *addr = __bitops_word(nr, ptr);
 164         unsigned long mask;
 165
 166 #ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
 167         if (__builtin_constant_p(nr)) {
 168                 unsigned char *caddr = __bitops_byte(nr, ptr);
 169
 170                 asm volatile(
 171                         "xi     %0,%b1\n"
 172                         : "+Q" (*caddr)
 173                         : "i" (1 << (nr & 7))
 174                         : "cc", "memory");
 175                 return;
 176         }
 177 #endif
 178         mask = 1UL << (nr & (BITS_PER_LONG - 1));
 179         __BITOPS_LOOP(addr, mask, __BITOPS_XOR, __BITOPS_NO_BARRIER);
 180 }
 181
 182 static inline int
 183 test_and_set_bit(unsigned long nr, volatile unsigned long *ptr)
 184 {
 185         unsigned long *addr = __bitops_word(nr, ptr);
 186         unsigned long old, mask;
 187
 188         mask = 1UL << (nr & (BITS_PER_LONG - 1));
 189         old = __BITOPS_LOOP(addr, mask, __BITOPS_OR, __BITOPS_BARRIER);
 190         return (old & mask) != 0;
 191 }
 192
 193 static inline int
 194 test_and_clear_bit(unsigned long nr, volatile unsigned long *ptr)
 195 {
 196         unsigned long *addr = __bitops_word(nr, ptr);
 197         unsigned long old, mask;
 198
 199         mask = ~(1UL << (nr & (BITS_PER_LONG - 1)));
 200         old = __BITOPS_LOOP(addr, mask, __BITOPS_AND, __BITOPS_BARRIER);
 201         return (old & ~mask) != 0;
 202 }
 203
 204 static inline int
 205 test_and_change_bit(unsigned long nr, volatile unsigned long *ptr)
 206 {
 207         unsigned long *addr = __bitops_word(nr, ptr);
 208         unsigned long old, mask;
 209
 210         mask = 1UL << (nr & (BITS_PER_LONG - 1));
 211         old = __BITOPS_LOOP(addr, mask, __BITOPS_XOR, __BITOPS_BARRIER);
 212         return (old & mask) != 0;
 213 }
 214
 215 static inline void __set_bit(unsigned long nr, volatile unsigned long *ptr)
 216 {
 217         unsigned char *addr = __bitops_byte(nr, ptr);
 218
 219         *addr |= 1 << (nr & 7);
 220 }
 221
 222 static inline void
 223 __clear_bit(unsigned long nr, volatile unsigned long *ptr)
 224 {
 225         unsigned char *addr = __bitops_byte(nr, ptr);
 226
 227         *addr &= ~(1 << (nr & 7));
 228 }
 229
 230 static inline void __change_bit(unsigned long nr, volatile unsigned long *ptr)
 231 {
 232         unsigned char *addr = __bitops_byte(nr, ptr);
 233
 234         *addr ^= 1 << (nr & 7);
 235 }
 236
 237 static inline int
 238 __test_and_set_bit(unsigned long nr, volatile unsigned long *ptr)
 239 {
 240         unsigned char *addr = __bitops_byte(nr, ptr);
 241         unsigned char ch;
 242
 243         ch = *addr;
 244         *addr |= 1 << (nr & 7);
 245         return (ch >> (nr & 7)) & 1;
 246 }
 247
 248 static inline int
 249 __test_and_clear_bit(unsigned long nr, volatile unsigned long *ptr)
 250 {
 251         unsigned char *addr = __bitops_byte(nr, ptr);
 252         unsigned char ch;
 253
 254         ch = *addr;
 255         *addr &= ~(1 << (nr & 7));
 256         return (ch >> (nr & 7)) & 1;
 257 }
 258
 259 static inline int
 260 __test_and_change_bit(unsigned long nr, volatile unsigned long *ptr)
 261 {
 262         unsigned char *addr = __bitops_byte(nr, ptr);
 263         unsigned char ch;
 264
 265         ch = *addr;
 266         *addr ^= 1 << (nr & 7);
 267         return (ch >> (nr & 7)) & 1;
 268 }
 269
 270 static inline int test_bit(unsigned long nr, const volatile unsigned long *ptr)
 271 {
 272         const volatile unsigned char *addr;
 273
 274         addr = ((const volatile unsigned char *)ptr);
 275         addr += (nr ^ (BITS_PER_LONG - 8)) >> 3;
 276         return (*addr >> (nr & 7)) & 1;
 277 }
 278
 279 static inline int test_and_set_bit_lock(unsigned long nr,
 280                                         volatile unsigned long *ptr)
 281 {
 282         if (test_bit(nr, ptr))
 283                 return 1;
 284         return test_and_set_bit(nr, ptr);
 285 }
 286
 287 static inline void clear_bit_unlock(unsigned long nr,
 288                                     volatile unsigned long *ptr)
 289 {
 290         smp_mb__before_atomic();
 291         clear_bit(nr, ptr);
 292 }
 293
 294 static inline void __clear_bit_unlock(unsigned long nr,
 295                                       volatile unsigned long *ptr)
 296 {
 297         smp_mb();
 298         __clear_bit(nr, ptr);
 299 }
 300
 301 /*
 302  * Functions which use MSB0 bit numbering.
 303  * On an s390x system the bits are numbered:
 304  *   |0..............63|64............127|128...........191|192...........255|
 305  * and on s390:
 306  *   |0.....31|32....63|64....95|96...127|128..159|160..191|192..223|224..255|
 307  */
 308 unsigned long find_first_bit_inv(const unsigned long *addr, unsigned long size);
 309 unsigned long find_next_bit_inv(const unsigned long *addr, unsigned long size,
 310                                 unsigned long offset);
 311
 312 static inline void set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
 313 {
 314         return set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 315 }
 316
 317 static inline void clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
 318 {
 319         return clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 320 }
 321
 322 static inline void __set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
 323 {
 324         return __set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 325 }
 326
 327 static inline void __clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
 328 {
 329         return __clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 330 }
 331
 332 static inline int test_bit_inv(unsigned long nr,
 333                                const volatile unsigned long *ptr)
 334 {
 335         return test_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 336 }
 337
 338 #ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
 339
 340 /**
 341  * __flogr - find leftmost one
 342  * @word - The word to search
 343  *
 344  * Returns the bit number of the most significant bit set,
 345  * where the most significant bit has bit number 0.
 346  * If no bit is set this function returns 64.
 347  */
 348 static inline unsigned char __flogr(unsigned long word)
 349 {
 350         if (__builtin_constant_p(word)) {
 351                 unsigned long bit = 0;
 352
 353                 if (!word)
 354                         return 64;
 355                 if (!(word & 0xffffffff00000000UL)) {
 356                         word <<= 32;
 357                         bit += 32;
 358                 }
 359                 if (!(word & 0xffff000000000000UL)) {
 360                         word <<= 16;
 361                         bit += 16;
 362                 }
 363                 if (!(word & 0xff00000000000000UL)) {
 364                         word <<= 8;
 365                         bit += 8;
 366                 }
 367                 if (!(word & 0xf000000000000000UL)) {
 368                         word <<= 4;
 369                         bit += 4;
 370                 }
 371                 if (!(word & 0xc000000000000000UL)) {
 372                         word <<= 2;
 373                         bit += 2;
 374                 }
 375                 if (!(word & 0x8000000000000000UL)) {
 376                         word <<= 1;
 377                         bit += 1;
 378                 }
 379                 return bit;
 380         } else {
 381                 register unsigned long bit asm("4") = word;
 382                 register unsigned long out asm("5");
 383
 384                 asm volatile(
 385                         "       flogr   %[bit],%[bit]\n"
 386                         : [bit] "+d" (bit), [out] "=d" (out) : : "cc");
 387                 return bit;
 388         }
 389 }
 390
 391 /**
 392  * __ffs - find first bit in word.
 393  * @word: The word to search
 394  *
 395  * Undefined if no bit exists, so code should check against 0 first.
 396  */
 397 static inline unsigned long __ffs(unsigned long word)
 398 {
 399         return __flogr(-word & word) ^ (BITS_PER_LONG - 1);
 400 }
 401
 402 /**
 403  * ffs - find first bit set
 404  * @word: the word to search
 405  *
 406  * This is defined the same way as the libc and
 407  * compiler builtin ffs routines (man ffs).
 408  */
 409 static inline int ffs(int word)
 410 {
 411         unsigned long mask = 2 * BITS_PER_LONG - 1;
 412         unsigned int val = (unsigned int)word;
 413
 414         return (1 + (__flogr(-val & val) ^ (BITS_PER_LONG - 1))) & mask;
 415 }
 416
 417 /**
 418  * __fls - find last (most-significant) set bit in a long word
 419  * @word: the word to search
 420  *
 421  * Undefined if no set bit exists, so code should check against 0 first.
 422  */
 423 static inline unsigned long __fls(unsigned long word)
 424 {
 425         return __flogr(word) ^ (BITS_PER_LONG - 1);
 426 }
 427
 428 /**
 429  * fls64 - find last set bit in a 64-bit word
 430  * @word: the word to search
 431  *
 432  * This is defined in a similar way as the libc and compiler builtin
 433  * ffsll, but returns the position of the most significant set bit.
 434  *
 435  * fls64(value) returns 0 if value is 0 or the position of the last
 436  * set bit if value is nonzero. The last (most significant) bit is
 437  * at position 64.
 438  */
 439 static inline int fls64(unsigned long word)
 440 {
 441         unsigned long mask = 2 * BITS_PER_LONG - 1;
 442
 443         return (1 + (__flogr(word) ^ (BITS_PER_LONG - 1))) & mask;
 444 }
 445
 446 /**
 447  * fls - find last (most-significant) bit set
 448  * @word: the word to search
 449  *
 450  * This is defined the same way as ffs.
 451  * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
 452  */
 453 static inline int fls(int word)
 454 {
 455         return fls64((unsigned int)word);
 456 }
 457
 458 #else /* CONFIG_HAVE_MARCH_Z9_109_FEATURES */
 459
 460 #include <asm-generic/bitops/__ffs.h>
 461 #include <asm-generic/bitops/ffs.h>
 462 #include <asm-generic/bitops/__fls.h>
 463 #include <asm-generic/bitops/fls.h>
 464 #include <asm-generic/bitops/fls64.h>
 465
 466 #endif /* CONFIG_HAVE_MARCH_Z9_109_FEATURES */
 467
 468 #include <asm-generic/bitops/ffz.h>
 469 #include <asm-generic/bitops/find.h>
 470 #include <asm-generic/bitops/hweight.h>
 471 #include <asm-generic/bitops/sched.h>
 472 #include <asm-generic/bitops/le.h>
 473 #include <asm-generic/bitops/ext2-atomic-setbit.h>
 474
 475 #endif /* _S390_BITOPS_H */