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 /*
 280  * Functions which use MSB0 bit numbering.
 281  * On an s390x system the bits are numbered:
 282  *   |0..............63|64............127|128...........191|192...........255|
 283  * and on s390:
 284  *   |0.....31|32....63|64....95|96...127|128..159|160..191|192..223|224..255|
 285  */
 286 unsigned long find_first_bit_inv(const unsigned long *addr, unsigned long size);
 287 unsigned long find_next_bit_inv(const unsigned long *addr, unsigned long size,
 288                                 unsigned long offset);
 289
 290 static inline void set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
 291 {
 292         return set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 293 }
 294
 295 static inline void clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
 296 {
 297         return clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 298 }
 299
 300 static inline void __set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
 301 {
 302         return __set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 303 }
 304
 305 static inline void __clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
 306 {
 307         return __clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 308 }
 309
 310 static inline int test_bit_inv(unsigned long nr,
 311                                const volatile unsigned long *ptr)
 312 {
 313         return test_bit(nr ^ (BITS_PER_LONG - 1), ptr);
 314 }
 315
 316 #ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
 317
 318 /**
 319  * __flogr - find leftmost one
 320  * @word - The word to search
 321  *
 322  * Returns the bit number of the most significant bit set,
 323  * where the most significant bit has bit number 0.
 324  * If no bit is set this function returns 64.
 325  */
 326 static inline unsigned char __flogr(unsigned long word)
 327 {
 328         if (__builtin_constant_p(word)) {
 329                 unsigned long bit = 0;
 330
 331                 if (!word)
 332                         return 64;
 333                 if (!(word & 0xffffffff00000000UL)) {
 334                         word <<= 32;
 335                         bit += 32;
 336                 }
 337                 if (!(word & 0xffff000000000000UL)) {
 338                         word <<= 16;
 339                         bit += 16;
 340                 }
 341                 if (!(word & 0xff00000000000000UL)) {
 342                         word <<= 8;
 343                         bit += 8;
 344                 }
 345                 if (!(word & 0xf000000000000000UL)) {
 346                         word <<= 4;
 347                         bit += 4;
 348                 }
 349                 if (!(word & 0xc000000000000000UL)) {
 350                         word <<= 2;
 351                         bit += 2;
 352                 }
 353                 if (!(word & 0x8000000000000000UL)) {
 354                         word <<= 1;
 355                         bit += 1;
 356                 }
 357                 return bit;
 358         } else {
 359                 register unsigned long bit asm("4") = word;
 360                 register unsigned long out asm("5");
 361
 362                 asm volatile(
 363                         "       flogr   %[bit],%[bit]\n"
 364                         : [bit] "+d" (bit), [out] "=d" (out) : : "cc");
 365                 return bit;
 366         }
 367 }
 368
 369 /**
 370  * __ffs - find first bit in word.
 371  * @word: The word to search
 372  *
 373  * Undefined if no bit exists, so code should check against 0 first.
 374  */
 375 static inline unsigned long __ffs(unsigned long word)
 376 {
 377         return __flogr(-word & word) ^ (BITS_PER_LONG - 1);
 378 }
 379
 380 /**
 381  * ffs - find first bit set
 382  * @word: the word to search
 383  *
 384  * This is defined the same way as the libc and
 385  * compiler builtin ffs routines (man ffs).
 386  */
 387 static inline int ffs(int word)
 388 {
 389         unsigned long mask = 2 * BITS_PER_LONG - 1;
 390         unsigned int val = (unsigned int)word;
 391
 392         return (1 + (__flogr(-val & val) ^ (BITS_PER_LONG - 1))) & mask;
 393 }
 394
 395 /**
 396  * __fls - find last (most-significant) set bit in a long word
 397  * @word: the word to search
 398  *
 399  * Undefined if no set bit exists, so code should check against 0 first.
 400  */
 401 static inline unsigned long __fls(unsigned long word)
 402 {
 403         return __flogr(word) ^ (BITS_PER_LONG - 1);
 404 }
 405
 406 /**
 407  * fls64 - find last set bit in a 64-bit word
 408  * @word: the word to search
 409  *
 410  * This is defined in a similar way as the libc and compiler builtin
 411  * ffsll, but returns the position of the most significant set bit.
 412  *
 413  * fls64(value) returns 0 if value is 0 or the position of the last
 414  * set bit if value is nonzero. The last (most significant) bit is
 415  * at position 64.
 416  */
 417 static inline int fls64(unsigned long word)
 418 {
 419         unsigned long mask = 2 * BITS_PER_LONG - 1;
 420
 421         return (1 + (__flogr(word) ^ (BITS_PER_LONG - 1))) & mask;
 422 }
 423
 424 /**
 425  * fls - find last (most-significant) bit set
 426  * @word: the word to search
 427  *
 428  * This is defined the same way as ffs.
 429  * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
 430  */
 431 static inline int fls(int word)
 432 {
 433         return fls64((unsigned int)word);
 434 }
 435
 436 #else /* CONFIG_HAVE_MARCH_Z9_109_FEATURES */
 437
 438 #include <asm-generic/bitops/__ffs.h>
 439 #include <asm-generic/bitops/ffs.h>
 440 #include <asm-generic/bitops/__fls.h>
 441 #include <asm-generic/bitops/fls.h>
 442 #include <asm-generic/bitops/fls64.h>
 443
 444 #endif /* CONFIG_HAVE_MARCH_Z9_109_FEATURES */
 445
 446 #include <asm-generic/bitops/ffz.h>
 447 #include <asm-generic/bitops/find.h>
 448 #include <asm-generic/bitops/hweight.h>
 449 #include <asm-generic/bitops/lock.h>
 450 #include <asm-generic/bitops/sched.h>
 451 #include <asm-generic/bitops/le.h>
 452 #include <asm-generic/bitops/ext2-atomic-setbit.h>
 453
 454 #endif /* _S390_BITOPS_H */