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, const 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 long __bitops_mask(unsigned long nr) 54 { 55 return 1UL << (nr & (BITS_PER_LONG - 1)); 56 } 57 58 static __always_inline void arch_set_bit(unsigned long nr, volatile unsigned long *ptr) 59 { 60 unsigned long *addr = __bitops_word(nr, ptr); 61 unsigned long mask = __bitops_mask(nr); 62 63 __atomic64_or(mask, (long *)addr); 64 } 65 66 static __always_inline void arch_clear_bit(unsigned long nr, volatile unsigned long *ptr) 67 { 68 unsigned long *addr = __bitops_word(nr, ptr); 69 unsigned long mask = __bitops_mask(nr); 70 71 __atomic64_and(~mask, (long *)addr); 72 } 73 74 static __always_inline void arch_change_bit(unsigned long nr, 75 volatile unsigned long *ptr) 76 { 77 unsigned long *addr = __bitops_word(nr, ptr); 78 unsigned long mask = __bitops_mask(nr); 79 80 __atomic64_xor(mask, (long *)addr); 81 } 82 83 static inline bool arch_test_and_set_bit(unsigned long nr, 84 volatile unsigned long *ptr) 85 { 86 unsigned long *addr = __bitops_word(nr, ptr); 87 unsigned long mask = __bitops_mask(nr); 88 unsigned long old; 89 90 old = __atomic64_or_barrier(mask, (long *)addr); 91 return old & mask; 92 } 93 94 static inline bool arch_test_and_clear_bit(unsigned long nr, 95 volatile unsigned long *ptr) 96 { 97 unsigned long *addr = __bitops_word(nr, ptr); 98 unsigned long mask = __bitops_mask(nr); 99 unsigned long old; 100 101 old = __atomic64_and_barrier(~mask, (long *)addr); 102 return old & mask; 103 } 104 105 static inline bool arch_test_and_change_bit(unsigned long nr, 106 volatile unsigned long *ptr) 107 { 108 unsigned long *addr = __bitops_word(nr, ptr); 109 unsigned long mask = __bitops_mask(nr); 110 unsigned long old; 111 112 old = __atomic64_xor_barrier(mask, (long *)addr); 113 return old & mask; 114 } 115 116 static __always_inline void 117 arch___set_bit(unsigned long nr, volatile unsigned long *addr) 118 { 119 unsigned long *p = __bitops_word(nr, addr); 120 unsigned long mask = __bitops_mask(nr); 121 122 *p |= mask; 123 } 124 125 static __always_inline void 126 arch___clear_bit(unsigned long nr, volatile unsigned long *addr) 127 { 128 unsigned long *p = __bitops_word(nr, addr); 129 unsigned long mask = __bitops_mask(nr); 130 131 *p &= ~mask; 132 } 133 134 static __always_inline void 135 arch___change_bit(unsigned long nr, volatile unsigned long *addr) 136 { 137 unsigned long *p = __bitops_word(nr, addr); 138 unsigned long mask = __bitops_mask(nr); 139 140 *p ^= mask; 141 } 142 143 static __always_inline bool 144 arch___test_and_set_bit(unsigned long nr, volatile unsigned long *addr) 145 { 146 unsigned long *p = __bitops_word(nr, addr); 147 unsigned long mask = __bitops_mask(nr); 148 unsigned long old; 149 150 old = *p; 151 *p |= mask; 152 return old & mask; 153 } 154 155 static __always_inline bool 156 arch___test_and_clear_bit(unsigned long nr, volatile unsigned long *addr) 157 { 158 unsigned long *p = __bitops_word(nr, addr); 159 unsigned long mask = __bitops_mask(nr); 160 unsigned long old; 161 162 old = *p; 163 *p &= ~mask; 164 return old & mask; 165 } 166 167 static __always_inline bool 168 arch___test_and_change_bit(unsigned long nr, volatile unsigned long *addr) 169 { 170 unsigned long *p = __bitops_word(nr, addr); 171 unsigned long mask = __bitops_mask(nr); 172 unsigned long old; 173 174 old = *p; 175 *p ^= mask; 176 return old & mask; 177 } 178 179 static __always_inline bool 180 arch_test_bit(unsigned long nr, const volatile unsigned long *addr) 181 { 182 const volatile unsigned long *p = __bitops_word(nr, addr); 183 unsigned long mask = __bitops_mask(nr); 184 185 return *p & mask; 186 } 187 188 static inline bool arch_test_and_set_bit_lock(unsigned long nr, 189 volatile unsigned long *ptr) 190 { 191 if (arch_test_bit(nr, ptr)) 192 return true; 193 return arch_test_and_set_bit(nr, ptr); 194 } 195 196 static inline void arch_clear_bit_unlock(unsigned long nr, 197 volatile unsigned long *ptr) 198 { 199 smp_mb__before_atomic(); 200 arch_clear_bit(nr, ptr); 201 } 202 203 static inline void arch___clear_bit_unlock(unsigned long nr, 204 volatile unsigned long *ptr) 205 { 206 smp_mb(); 207 arch___clear_bit(nr, ptr); 208 } 209 210 #include <asm-generic/bitops/instrumented-atomic.h> 211 #include <asm-generic/bitops/instrumented-non-atomic.h> 212 #include <asm-generic/bitops/instrumented-lock.h> 213 214 /* 215 * Functions which use MSB0 bit numbering. 216 * The bits are numbered: 217 * |0..............63|64............127|128...........191|192...........255| 218 */ 219 unsigned long find_first_bit_inv(const unsigned long *addr, unsigned long size); 220 unsigned long find_next_bit_inv(const unsigned long *addr, unsigned long size, 221 unsigned long offset); 222 223 #define for_each_set_bit_inv(bit, addr, size) \ 224 for ((bit) = find_first_bit_inv((addr), (size)); \ 225 (bit) < (size); \ 226 (bit) = find_next_bit_inv((addr), (size), (bit) + 1)) 227 228 static inline void set_bit_inv(unsigned long nr, volatile unsigned long *ptr) 229 { 230 return set_bit(nr ^ (BITS_PER_LONG - 1), ptr); 231 } 232 233 static inline void clear_bit_inv(unsigned long nr, volatile unsigned long *ptr) 234 { 235 return clear_bit(nr ^ (BITS_PER_LONG - 1), ptr); 236 } 237 238 static inline bool test_and_clear_bit_inv(unsigned long nr, 239 volatile unsigned long *ptr) 240 { 241 return test_and_clear_bit(nr ^ (BITS_PER_LONG - 1), ptr); 242 } 243 244 static inline void __set_bit_inv(unsigned long nr, volatile unsigned long *ptr) 245 { 246 return __set_bit(nr ^ (BITS_PER_LONG - 1), ptr); 247 } 248 249 static inline void __clear_bit_inv(unsigned long nr, volatile unsigned long *ptr) 250 { 251 return __clear_bit(nr ^ (BITS_PER_LONG - 1), ptr); 252 } 253 254 static inline bool test_bit_inv(unsigned long nr, 255 const volatile unsigned long *ptr) 256 { 257 return test_bit(nr ^ (BITS_PER_LONG - 1), ptr); 258 } 259 260 /** 261 * __flogr - find leftmost one 262 * @word - The word to search 263 * 264 * Returns the bit number of the most significant bit set, 265 * where the most significant bit has bit number 0. 266 * If no bit is set this function returns 64. 267 */ 268 static inline unsigned char __flogr(unsigned long word) 269 { 270 if (__builtin_constant_p(word)) { 271 unsigned long bit = 0; 272 273 if (!word) 274 return 64; 275 if (!(word & 0xffffffff00000000UL)) { 276 word <<= 32; 277 bit += 32; 278 } 279 if (!(word & 0xffff000000000000UL)) { 280 word <<= 16; 281 bit += 16; 282 } 283 if (!(word & 0xff00000000000000UL)) { 284 word <<= 8; 285 bit += 8; 286 } 287 if (!(word & 0xf000000000000000UL)) { 288 word <<= 4; 289 bit += 4; 290 } 291 if (!(word & 0xc000000000000000UL)) { 292 word <<= 2; 293 bit += 2; 294 } 295 if (!(word & 0x8000000000000000UL)) { 296 word <<= 1; 297 bit += 1; 298 } 299 return bit; 300 } else { 301 union register_pair rp; 302 303 rp.even = word; 304 asm volatile( 305 " flogr %[rp],%[rp]\n" 306 : [rp] "+d" (rp.pair) : : "cc"); 307 return rp.even; 308 } 309 } 310 311 /** 312 * __ffs - find first bit in word. 313 * @word: The word to search 314 * 315 * Undefined if no bit exists, so code should check against 0 first. 316 */ 317 static inline unsigned long __ffs(unsigned long word) 318 { 319 return __flogr(-word & word) ^ (BITS_PER_LONG - 1); 320 } 321 322 /** 323 * ffs - find first bit set 324 * @word: the word to search 325 * 326 * This is defined the same way as the libc and 327 * compiler builtin ffs routines (man ffs). 328 */ 329 static inline int ffs(int word) 330 { 331 unsigned long mask = 2 * BITS_PER_LONG - 1; 332 unsigned int val = (unsigned int)word; 333 334 return (1 + (__flogr(-val & val) ^ (BITS_PER_LONG - 1))) & mask; 335 } 336 337 /** 338 * __fls - find last (most-significant) set bit in a long word 339 * @word: the word to search 340 * 341 * Undefined if no set bit exists, so code should check against 0 first. 342 */ 343 static inline unsigned long __fls(unsigned long word) 344 { 345 return __flogr(word) ^ (BITS_PER_LONG - 1); 346 } 347 348 /** 349 * fls64 - find last set bit in a 64-bit word 350 * @word: the word to search 351 * 352 * This is defined in a similar way as the libc and compiler builtin 353 * ffsll, but returns the position of the most significant set bit. 354 * 355 * fls64(value) returns 0 if value is 0 or the position of the last 356 * set bit if value is nonzero. The last (most significant) bit is 357 * at position 64. 358 */ 359 static inline int fls64(unsigned long word) 360 { 361 unsigned long mask = 2 * BITS_PER_LONG - 1; 362 363 return (1 + (__flogr(word) ^ (BITS_PER_LONG - 1))) & mask; 364 } 365 366 /** 367 * fls - find last (most-significant) bit set 368 * @word: the word to search 369 * 370 * This is defined the same way as ffs. 371 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. 372 */ 373 static inline int fls(unsigned int word) 374 { 375 return fls64(word); 376 } 377 378 #include <asm-generic/bitops/ffz.h> 379 #include <asm-generic/bitops/hweight.h> 380 #include <asm-generic/bitops/sched.h> 381 #include <asm-generic/bitops/le.h> 382 #include <asm-generic/bitops/ext2-atomic-setbit.h> 383 384 #endif /* _S390_BITOPS_H */ 385