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...........196|
  17  * and on s390:
  18  *   |31.....0|63....31|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|31....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
  51 #ifndef CONFIG_64BIT
  52
  53 #define __BITOPS_OR             "or"
  54 #define __BITOPS_AND            "nr"
  55 #define __BITOPS_XOR            "xr"
  56
  57 #define __BITOPS_LOOP(__addr, __val, __op_string)               \
  58 ({                                                              \
  59         unsigned long __old, __new;                             \
  60                                                                 \
  61         typecheck(unsigned long *, (__addr));                   \
  62         asm volatile(                                           \
  63                 "       l       %0,%2\n"                        \
  64                 "0:     lr      %1,%0\n"                        \
  65                 __op_string "   %1,%3\n"                        \
  66                 "       cs      %0,%1,%2\n"                     \
  67                 "       jl      0b"                             \
  68                 : "=&d" (__old), "=&d" (__new), "+Q" (*(__addr))\
  69                 : "d" (__val)                                   \
  70                 : "cc");                                        \
  71         __old;                                                  \
  72 })
  73
  74 #else /* CONFIG_64BIT */
  75
  76 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
  77
  78 #define __BITOPS_OR             "laog"
  79 #define __BITOPS_AND            "lang"
  80 #define __BITOPS_XOR            "laxg"
  81
  82 #define __BITOPS_LOOP(__addr, __val, __op_string)               \
  83 ({                                                              \
  84         unsigned long __old;                                    \
  85                                                                 \
  86         typecheck(unsigned long *, (__addr));                   \
  87         asm volatile(                                           \
  88                 __op_string "   %0,%2,%1\n"                     \
  89                 : "=d" (__old), "+Q" (*(__addr))                \
  90                 : "d" (__val)                                   \
  91                 : "cc");                                        \
  92         __old;                                                  \
  93 })
  94
  95 #else /* CONFIG_HAVE_MARCH_Z196_FEATURES */
  96
  97 #define __BITOPS_OR             "ogr"
  98 #define __BITOPS_AND            "ngr"
  99 #define __BITOPS_XOR            "xgr"
 100
 101 #define __BITOPS_LOOP(__addr, __val, __op_string)               \
 102 ({                                                              \
 103         unsigned long __old, __new;                             \
 104                                                                 \
 105         typecheck(unsigned long *, (__addr));                   \
 106         asm volatile(                                           \
 107                 "       lg      %0,%2\n"                        \
 108                 "0:     lgr     %1,%0\n"                        \
 109                 __op_string "   %1,%3\n"                        \
 110                 "       csg     %0,%1,%2\n"                     \
 111                 "       jl      0b"                             \
 112                 : "=&d" (__old), "=&d" (__new), "+Q" (*(__addr))\
 113                 : "d" (__val)                                   \
 114                 : "cc");                                        \
 115         __old;                                                  \
 116 })
 117
 118 #endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */
 119
 120 #endif /* CONFIG_64BIT */
 121
 122 #define __BITOPS_WORDS(bits) (((bits) + BITS_PER_LONG - 1) / BITS_PER_LONG)
 123
 124 static inline unsigned long *
 125 __bitops_word(unsigned long nr, volatile unsigned long *ptr)
 126 {
 127         unsigned long addr;
 128
 129         addr = (unsigned long)ptr + ((nr ^ (nr & (BITS_PER_LONG - 1))) >> 3);
 130         return (unsigned long *)addr;
 131 }
 132
 133 static inline unsigned char *
 134 __bitops_byte(unsigned long nr, volatile unsigned long *ptr)
 135 {
 136         return ((unsigned char *)ptr) + ((nr ^ (BITS_PER_LONG - 8)) >> 3);
 137 }
 138
 139 static inline void set_bit(unsigned long nr, volatile unsigned long *ptr)
 140 {
 141         unsigned long *addr = __bitops_word(nr, ptr);
 142         unsigned long mask;
 143
 144 #ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
 145         if (__builtin_constant_p(nr)) {
 146                 unsigned char *caddr = __bitops_byte(nr, ptr);
 147
 148                 asm volatile(
 149                         "oi     %0,%b1\n"
 150                         : "+Q" (*caddr)
 151                         : "i" (1 << (nr & 7))
 152                         : "cc");
 153                 return;
 154         }
 155 #endif
 156         mask = 1UL << (nr & (BITS_PER_LONG - 1));
 157         __BITOPS_LOOP(addr, mask, __BITOPS_OR);
 158 }
 159
 160 static inline void clear_bit(unsigned long nr, volatile unsigned long *ptr)
 161 {
 162         unsigned long *addr = __bitops_word(nr, ptr);
 163         unsigned long mask;
 164
 165 #ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
 166         if (__builtin_constant_p(nr)) {
 167                 unsigned char *caddr = __bitops_byte(nr, ptr);
 168
 169                 asm volatile(
 170                         "ni     %0,%b1\n"
 171                         : "+Q" (*caddr)
 172                         : "i" (~(1 << (nr & 7)))
 173                         : "cc");
 174                 return;
 175         }
 176 #endif
 177         mask = ~(1UL << (nr & (BITS_PER_LONG - 1)));
 178         __BITOPS_LOOP(addr, mask, __BITOPS_AND);
 179 }
 180
 181 static inline void change_bit(unsigned long nr, volatile unsigned long *ptr)
 182 {
 183         unsigned long *addr = __bitops_word(nr, ptr);
 184         unsigned long mask;
 185
 186 #ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
 187         if (__builtin_constant_p(nr)) {
 188                 unsigned char *caddr = __bitops_byte(nr, ptr);
 189
 190                 asm volatile(
 191                         "xi     %0,%b1\n"
 192                         : "+Q" (*caddr)
 193                         : "i" (1 << (nr & 7))
 194                         : "cc");
 195                 return;
 196         }
 197 #endif
 198         mask = 1UL << (nr & (BITS_PER_LONG - 1));
 199         __BITOPS_LOOP(addr, mask, __BITOPS_XOR);
 200 }
 201
 202 static inline int
 203 test_and_set_bit(unsigned long nr, volatile unsigned long *ptr)
 204 {
 205         unsigned long *addr = __bitops_word(nr, ptr);
 206         unsigned long old, mask;
 207
 208         mask = 1UL << (nr & (BITS_PER_LONG - 1));
 209         old = __BITOPS_LOOP(addr, mask, __BITOPS_OR);
 210         barrier();
 211         return (old & mask) != 0;
 212 }
 213
 214 static inline int
 215 test_and_clear_bit(unsigned long nr, volatile unsigned long *ptr)
 216 {
 217         unsigned long *addr = __bitops_word(nr, ptr);
 218         unsigned long old, mask;
 219
 220         mask = ~(1UL << (nr & (BITS_PER_LONG - 1)));
 221         old = __BITOPS_LOOP(addr, mask, __BITOPS_AND);
 222         barrier();
 223         return (old & ~mask) != 0;
 224 }
 225
 226 static inline int
 227 test_and_change_bit(unsigned long nr, volatile unsigned long *ptr)
 228 {
 229         unsigned long *addr = __bitops_word(nr, ptr);
 230         unsigned long old, mask;
 231
 232         mask = 1UL << (nr & (BITS_PER_LONG - 1));
 233         old = __BITOPS_LOOP(addr, mask, __BITOPS_XOR);
 234         barrier();
 235         return (old & mask) != 0;
 236 }
 237
 238 static inline void __set_bit(unsigned long nr, volatile unsigned long *ptr)
 239 {
 240         unsigned char *addr = __bitops_byte(nr, ptr);
 241
 242         *addr |= 1 << (nr & 7);
 243 }
 244
 245 static inline void
 246 __clear_bit(unsigned long nr, volatile unsigned long *ptr)
 247 {
 248         unsigned char *addr = __bitops_byte(nr, ptr);
 249
 250         *addr &= ~(1 << (nr & 7));
 251 }
 252
 253 static inline void __change_bit(unsigned long nr, volatile unsigned long *ptr)
 254 {
 255         unsigned char *addr = __bitops_byte(nr, ptr);
 256
 257         *addr ^= 1 << (nr & 7);
 258 }
 259
 260 static inline int
 261 __test_and_set_bit(unsigned long nr, volatile unsigned long *ptr)
 262 {
 263         unsigned char *addr = __bitops_byte(nr, ptr);
 264         unsigned char ch;
 265
 266         ch = *addr;
 267         *addr |= 1 << (nr & 7);
 268         return (ch >> (nr & 7)) & 1;
 269 }
 270
 271 static inline int
 272 __test_and_clear_bit(unsigned long nr, volatile unsigned long *ptr)
 273 {
 274         unsigned char *addr = __bitops_byte(nr, ptr);
 275         unsigned char ch;
 276
 277         ch = *addr;
 278         *addr &= ~(1 << (nr & 7));
 279         return (ch >> (nr & 7)) & 1;
 280 }
 281
 282 static inline int
 283 __test_and_change_bit(unsigned long nr, volatile unsigned long *ptr)
 284 {
 285         unsigned char *addr = __bitops_byte(nr, ptr);
 286         unsigned char ch;
 287
 288         ch = *addr;
 289         *addr ^= 1 << (nr & 7);
 290         return (ch >> (nr & 7)) & 1;
 291 }
 292
 293 static inline int test_bit(unsigned long nr, const volatile unsigned long *ptr)
 294 {
 295         const volatile unsigned char *addr;
 296
 297         addr = ((const volatile unsigned char *)ptr);
 298         addr += (nr ^ (BITS_PER_LONG - 8)) >> 3;
 299         return (*addr >> (nr & 7)) & 1;
 300 }
 301
 302 /*
 303  * ATTENTION:
 304  * find_first_bit_left() and find_next_bit_left() use MSB0 encoding.
 305  */
 306 unsigned long find_first_bit_left(const unsigned long *addr, unsigned long size);
 307 unsigned long find_next_bit_left(const unsigned long *addr, unsigned long size,
 308                                  unsigned long offset);
 309
 310 #ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
 311
 312 /**
 313  * __flogr - find leftmost one
 314  * @word - The word to search
 315  *
 316  * Returns the bit number of the most significant bit set,
 317  * where the most significant bit has bit number 0.
 318  * If no bit is set this function returns 64.
 319  */
 320 static inline unsigned char __flogr(unsigned long word)
 321 {
 322         if (__builtin_constant_p(word)) {
 323                 unsigned long bit = 0;
 324
 325                 if (!word)
 326                         return 64;
 327                 if (!(word & 0xffffffff00000000UL)) {
 328                         word <<= 32;
 329                         bit += 32;
 330                 }
 331                 if (!(word & 0xffff000000000000UL)) {
 332                         word <<= 16;
 333                         bit += 16;
 334                 }
 335                 if (!(word & 0xff00000000000000UL)) {
 336                         word <<= 8;
 337                         bit += 8;
 338                 }
 339                 if (!(word & 0xf000000000000000UL)) {
 340                         word <<= 4;
 341                         bit += 4;
 342                 }
 343                 if (!(word & 0xc000000000000000UL)) {
 344                         word <<= 2;
 345                         bit += 2;
 346                 }
 347                 if (!(word & 0x8000000000000000UL)) {
 348                         word <<= 1;
 349                         bit += 1;
 350                 }
 351                 return bit;
 352         } else {
 353                 register unsigned long bit asm("4") = word;
 354                 register unsigned long out asm("5");
 355
 356                 asm volatile(
 357                         "       flogr   %[bit],%[bit]\n"
 358                         : [bit] "+d" (bit), [out] "=d" (out) : : "cc");
 359                 return bit;
 360         }
 361 }
 362
 363 /**
 364  * __ffs - find first bit in word.
 365  * @word: The word to search
 366  *
 367  * Undefined if no bit exists, so code should check against 0 first.
 368  */
 369 static inline unsigned long __ffs(unsigned long word)
 370 {
 371         return __flogr(-word & word) ^ (BITS_PER_LONG - 1);
 372 }
 373
 374 /**
 375  * ffs - find first bit set
 376  * @word: the word to search
 377  *
 378  * This is defined the same way as the libc and
 379  * compiler builtin ffs routines (man ffs).
 380  */
 381 static inline int ffs(int word)
 382 {
 383         unsigned long mask = 2 * BITS_PER_LONG - 1;
 384         unsigned int val = (unsigned int)word;
 385
 386         return (1 + (__flogr(-val & val) ^ (BITS_PER_LONG - 1))) & mask;
 387 }
 388
 389 /**
 390  * __fls - find last (most-significant) set bit in a long word
 391  * @word: the word to search
 392  *
 393  * Undefined if no set bit exists, so code should check against 0 first.
 394  */
 395 static inline unsigned long __fls(unsigned long word)
 396 {
 397         return __flogr(word) ^ (BITS_PER_LONG - 1);
 398 }
 399
 400 /**
 401  * fls64 - find last set bit in a 64-bit word
 402  * @word: the word to search
 403  *
 404  * This is defined in a similar way as the libc and compiler builtin
 405  * ffsll, but returns the position of the most significant set bit.
 406  *
 407  * fls64(value) returns 0 if value is 0 or the position of the last
 408  * set bit if value is nonzero. The last (most significant) bit is
 409  * at position 64.
 410  */
 411 static inline int fls64(unsigned long word)
 412 {
 413         unsigned long mask = 2 * BITS_PER_LONG - 1;
 414
 415         return (1 + (__flogr(word) ^ (BITS_PER_LONG - 1))) & mask;
 416 }
 417
 418 /**
 419  * fls - find last (most-significant) bit set
 420  * @word: the word to search
 421  *
 422  * This is defined the same way as ffs.
 423  * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
 424  */
 425 static inline int fls(int word)
 426 {
 427         return fls64((unsigned int)word);
 428 }
 429
 430 #else /* CONFIG_HAVE_MARCH_Z9_109_FEATURES */
 431
 432 #include <asm-generic/bitops/__ffs.h>
 433 #include <asm-generic/bitops/ffs.h>
 434 #include <asm-generic/bitops/__fls.h>
 435 #include <asm-generic/bitops/fls.h>
 436 #include <asm-generic/bitops/fls64.h>
 437
 438 #endif /* CONFIG_HAVE_MARCH_Z9_109_FEATURES */
 439
 440 #include <asm-generic/bitops/ffz.h>
 441 #include <asm-generic/bitops/find.h>
 442 #include <asm-generic/bitops/hweight.h>
 443 #include <asm-generic/bitops/lock.h>
 444 #include <asm-generic/bitops/sched.h>
 445 #include <asm-generic/bitops/le.h>
 446 #include <asm-generic/bitops/ext2-atomic-setbit.h>
 447
 448 #endif /* _S390_BITOPS_H */