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 #define arch_test_bit generic_test_bit 180 #define arch_test_bit_acquire generic_test_bit_acquire 181 182 static inline bool arch_test_and_set_bit_lock(unsigned long nr, 183 volatile unsigned long *ptr) 184 { 185 if (arch_test_bit(nr, ptr)) 186 return true; 187 return arch_test_and_set_bit(nr, ptr); 188 } 189 190 static inline void arch_clear_bit_unlock(unsigned long nr, 191 volatile unsigned long *ptr) 192 { 193 smp_mb__before_atomic(); 194 arch_clear_bit(nr, ptr); 195 } 196 197 static inline void arch___clear_bit_unlock(unsigned long nr, 198 volatile unsigned long *ptr) 199 { 200 smp_mb(); 201 arch___clear_bit(nr, ptr); 202 } 203 204 #include <asm-generic/bitops/instrumented-atomic.h> 205 #include <asm-generic/bitops/instrumented-non-atomic.h> 206 #include <asm-generic/bitops/instrumented-lock.h> 207 208 /* 209 * Functions which use MSB0 bit numbering. 210 * The bits are numbered: 211 * |0..............63|64............127|128...........191|192...........255| 212 */ 213 unsigned long find_first_bit_inv(const unsigned long *addr, unsigned long size); 214 unsigned long find_next_bit_inv(const unsigned long *addr, unsigned long size, 215 unsigned long offset); 216 217 #define for_each_set_bit_inv(bit, addr, size) \ 218 for ((bit) = find_first_bit_inv((addr), (size)); \ 219 (bit) < (size); \ 220 (bit) = find_next_bit_inv((addr), (size), (bit) + 1)) 221 222 static inline void set_bit_inv(unsigned long nr, volatile unsigned long *ptr) 223 { 224 return set_bit(nr ^ (BITS_PER_LONG - 1), ptr); 225 } 226 227 static inline void clear_bit_inv(unsigned long nr, volatile unsigned long *ptr) 228 { 229 return clear_bit(nr ^ (BITS_PER_LONG - 1), ptr); 230 } 231 232 static inline bool test_and_clear_bit_inv(unsigned long nr, 233 volatile unsigned long *ptr) 234 { 235 return test_and_clear_bit(nr ^ (BITS_PER_LONG - 1), ptr); 236 } 237 238 static inline void __set_bit_inv(unsigned long nr, volatile unsigned long *ptr) 239 { 240 return __set_bit(nr ^ (BITS_PER_LONG - 1), ptr); 241 } 242 243 static inline void __clear_bit_inv(unsigned long nr, volatile unsigned long *ptr) 244 { 245 return __clear_bit(nr ^ (BITS_PER_LONG - 1), ptr); 246 } 247 248 static inline bool test_bit_inv(unsigned long nr, 249 const volatile unsigned long *ptr) 250 { 251 return test_bit(nr ^ (BITS_PER_LONG - 1), ptr); 252 } 253 254 /** 255 * __flogr - find leftmost one 256 * @word - The word to search 257 * 258 * Returns the bit number of the most significant bit set, 259 * where the most significant bit has bit number 0. 260 * If no bit is set this function returns 64. 261 */ 262 static inline unsigned char __flogr(unsigned long word) 263 { 264 if (__builtin_constant_p(word)) { 265 unsigned long bit = 0; 266 267 if (!word) 268 return 64; 269 if (!(word & 0xffffffff00000000UL)) { 270 word <<= 32; 271 bit += 32; 272 } 273 if (!(word & 0xffff000000000000UL)) { 274 word <<= 16; 275 bit += 16; 276 } 277 if (!(word & 0xff00000000000000UL)) { 278 word <<= 8; 279 bit += 8; 280 } 281 if (!(word & 0xf000000000000000UL)) { 282 word <<= 4; 283 bit += 4; 284 } 285 if (!(word & 0xc000000000000000UL)) { 286 word <<= 2; 287 bit += 2; 288 } 289 if (!(word & 0x8000000000000000UL)) { 290 word <<= 1; 291 bit += 1; 292 } 293 return bit; 294 } else { 295 union register_pair rp; 296 297 rp.even = word; 298 asm volatile( 299 " flogr %[rp],%[rp]\n" 300 : [rp] "+d" (rp.pair) : : "cc"); 301 return rp.even; 302 } 303 } 304 305 /** 306 * __ffs - find first bit in word. 307 * @word: The word to search 308 * 309 * Undefined if no bit exists, so code should check against 0 first. 310 */ 311 static inline unsigned long __ffs(unsigned long word) 312 { 313 return __flogr(-word & word) ^ (BITS_PER_LONG - 1); 314 } 315 316 /** 317 * ffs - find first bit set 318 * @word: the word to search 319 * 320 * This is defined the same way as the libc and 321 * compiler builtin ffs routines (man ffs). 322 */ 323 static inline int ffs(int word) 324 { 325 unsigned long mask = 2 * BITS_PER_LONG - 1; 326 unsigned int val = (unsigned int)word; 327 328 return (1 + (__flogr(-val & val) ^ (BITS_PER_LONG - 1))) & mask; 329 } 330 331 /** 332 * __fls - find last (most-significant) set bit in a long word 333 * @word: the word to search 334 * 335 * Undefined if no set bit exists, so code should check against 0 first. 336 */ 337 static inline unsigned long __fls(unsigned long word) 338 { 339 return __flogr(word) ^ (BITS_PER_LONG - 1); 340 } 341 342 /** 343 * fls64 - find last set bit in a 64-bit word 344 * @word: the word to search 345 * 346 * This is defined in a similar way as the libc and compiler builtin 347 * ffsll, but returns the position of the most significant set bit. 348 * 349 * fls64(value) returns 0 if value is 0 or the position of the last 350 * set bit if value is nonzero. The last (most significant) bit is 351 * at position 64. 352 */ 353 static inline int fls64(unsigned long word) 354 { 355 unsigned long mask = 2 * BITS_PER_LONG - 1; 356 357 return (1 + (__flogr(word) ^ (BITS_PER_LONG - 1))) & mask; 358 } 359 360 /** 361 * fls - find last (most-significant) bit set 362 * @word: the word to search 363 * 364 * This is defined the same way as ffs. 365 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. 366 */ 367 static inline int fls(unsigned int word) 368 { 369 return fls64(word); 370 } 371 372 #include <asm-generic/bitops/ffz.h> 373 #include <asm-generic/bitops/hweight.h> 374 #include <asm-generic/bitops/sched.h> 375 #include <asm-generic/bitops/le.h> 376 #include <asm-generic/bitops/ext2-atomic-setbit.h> 377 378 #endif /* _S390_BITOPS_H */ 379