1 #ifndef _LINUX_KERNEL_H 2 #define _LINUX_KERNEL_H 3 4 5 #include <stdarg.h> 6 #include <linux/linkage.h> 7 #include <linux/stddef.h> 8 #include <linux/types.h> 9 #include <linux/compiler.h> 10 #include <linux/bitops.h> 11 #include <linux/log2.h> 12 #include <linux/typecheck.h> 13 #include <linux/printk.h> 14 #include <linux/dynamic_debug.h> 15 #include <asm/byteorder.h> 16 #include <uapi/linux/kernel.h> 17 18 #define USHRT_MAX ((u16)(~0U)) 19 #define SHRT_MAX ((s16)(USHRT_MAX>>1)) 20 #define SHRT_MIN ((s16)(-SHRT_MAX - 1)) 21 #define INT_MAX ((int)(~0U>>1)) 22 #define INT_MIN (-INT_MAX - 1) 23 #define UINT_MAX (~0U) 24 #define LONG_MAX ((long)(~0UL>>1)) 25 #define LONG_MIN (-LONG_MAX - 1) 26 #define ULONG_MAX (~0UL) 27 #define LLONG_MAX ((long long)(~0ULL>>1)) 28 #define LLONG_MIN (-LLONG_MAX - 1) 29 #define ULLONG_MAX (~0ULL) 30 #define SIZE_MAX (~(size_t)0) 31 32 #define STACK_MAGIC 0xdeadbeef 33 34 #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x)) 35 36 #define ALIGN(x, a) __ALIGN_KERNEL((x), (a)) 37 #define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask)) 38 #define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a))) 39 #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0) 40 41 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr)) 42 43 /* 44 * This looks more complex than it should be. But we need to 45 * get the type for the ~ right in round_down (it needs to be 46 * as wide as the result!), and we want to evaluate the macro 47 * arguments just once each. 48 */ 49 #define __round_mask(x, y) ((__typeof__(x))((y)-1)) 50 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1) 51 #define round_down(x, y) ((x) & ~__round_mask(x, y)) 52 53 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f)) 54 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d)) 55 #define DIV_ROUND_UP_ULL(ll,d) \ 56 ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; }) 57 58 #if BITS_PER_LONG == 32 59 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d) 60 #else 61 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d) 62 #endif 63 64 /* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */ 65 #define roundup(x, y) ( \ 66 { \ 67 const typeof(y) __y = y; \ 68 (((x) + (__y - 1)) / __y) * __y; \ 69 } \ 70 ) 71 #define rounddown(x, y) ( \ 72 { \ 73 typeof(x) __x = (x); \ 74 __x - (__x % (y)); \ 75 } \ 76 ) 77 78 /* 79 * Divide positive or negative dividend by positive divisor and round 80 * to closest integer. Result is undefined for negative divisors and 81 * for negative dividends if the divisor variable type is unsigned. 82 */ 83 #define DIV_ROUND_CLOSEST(x, divisor)( \ 84 { \ 85 typeof(x) __x = x; \ 86 typeof(divisor) __d = divisor; \ 87 (((typeof(x))-1) > 0 || \ 88 ((typeof(divisor))-1) > 0 || (__x) > 0) ? \ 89 (((__x) + ((__d) / 2)) / (__d)) : \ 90 (((__x) - ((__d) / 2)) / (__d)); \ 91 } \ 92 ) 93 94 /* 95 * Multiplies an integer by a fraction, while avoiding unnecessary 96 * overflow or loss of precision. 97 */ 98 #define mult_frac(x, numer, denom)( \ 99 { \ 100 typeof(x) quot = (x) / (denom); \ 101 typeof(x) rem = (x) % (denom); \ 102 (quot * (numer)) + ((rem * (numer)) / (denom)); \ 103 } \ 104 ) 105 106 107 #define _RET_IP_ (unsigned long)__builtin_return_address(0) 108 #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; }) 109 110 #ifdef CONFIG_LBDAF 111 # include <asm/div64.h> 112 # define sector_div(a, b) do_div(a, b) 113 #else 114 # define sector_div(n, b)( \ 115 { \ 116 int _res; \ 117 _res = (n) % (b); \ 118 (n) /= (b); \ 119 _res; \ 120 } \ 121 ) 122 #endif 123 124 /** 125 * upper_32_bits - return bits 32-63 of a number 126 * @n: the number we're accessing 127 * 128 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress 129 * the "right shift count >= width of type" warning when that quantity is 130 * 32-bits. 131 */ 132 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16)) 133 134 /** 135 * lower_32_bits - return bits 0-31 of a number 136 * @n: the number we're accessing 137 */ 138 #define lower_32_bits(n) ((u32)(n)) 139 140 struct completion; 141 struct pt_regs; 142 struct user; 143 144 #ifdef CONFIG_PREEMPT_VOLUNTARY 145 extern int _cond_resched(void); 146 # define might_resched() _cond_resched() 147 #else 148 # define might_resched() do { } while (0) 149 #endif 150 151 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 152 void __might_sleep(const char *file, int line, int preempt_offset); 153 /** 154 * might_sleep - annotation for functions that can sleep 155 * 156 * this macro will print a stack trace if it is executed in an atomic 157 * context (spinlock, irq-handler, ...). 158 * 159 * This is a useful debugging help to be able to catch problems early and not 160 * be bitten later when the calling function happens to sleep when it is not 161 * supposed to. 162 */ 163 # define might_sleep() \ 164 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0) 165 #else 166 static inline void __might_sleep(const char *file, int line, 167 int preempt_offset) { } 168 # define might_sleep() do { might_resched(); } while (0) 169 #endif 170 171 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0) 172 173 /* 174 * abs() handles unsigned and signed longs, ints, shorts and chars. For all 175 * input types abs() returns a signed long. 176 * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64() 177 * for those. 178 */ 179 #define abs(x) ({ \ 180 long ret; \ 181 if (sizeof(x) == sizeof(long)) { \ 182 long __x = (x); \ 183 ret = (__x < 0) ? -__x : __x; \ 184 } else { \ 185 int __x = (x); \ 186 ret = (__x < 0) ? -__x : __x; \ 187 } \ 188 ret; \ 189 }) 190 191 #define abs64(x) ({ \ 192 s64 __x = (x); \ 193 (__x < 0) ? -__x : __x; \ 194 }) 195 196 #ifdef CONFIG_PROVE_LOCKING 197 void might_fault(void); 198 #else 199 static inline void might_fault(void) 200 { 201 might_sleep(); 202 } 203 #endif 204 205 extern struct atomic_notifier_head panic_notifier_list; 206 extern long (*panic_blink)(int state); 207 __printf(1, 2) 208 void panic(const char *fmt, ...) 209 __noreturn __cold; 210 extern void oops_enter(void); 211 extern void oops_exit(void); 212 void print_oops_end_marker(void); 213 extern int oops_may_print(void); 214 void do_exit(long error_code) 215 __noreturn; 216 void complete_and_exit(struct completion *, long) 217 __noreturn; 218 219 /* Internal, do not use. */ 220 int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res); 221 int __must_check _kstrtol(const char *s, unsigned int base, long *res); 222 223 int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res); 224 int __must_check kstrtoll(const char *s, unsigned int base, long long *res); 225 226 /** 227 * kstrtoul - convert a string to an unsigned long 228 * @s: The start of the string. The string must be null-terminated, and may also 229 * include a single newline before its terminating null. The first character 230 * may also be a plus sign, but not a minus sign. 231 * @base: The number base to use. The maximum supported base is 16. If base is 232 * given as 0, then the base of the string is automatically detected with the 233 * conventional semantics - If it begins with 0x the number will be parsed as a 234 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 235 * parsed as an octal number. Otherwise it will be parsed as a decimal. 236 * @res: Where to write the result of the conversion on success. 237 * 238 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 239 * Used as a replacement for the obsolete simple_strtoull. Return code must 240 * be checked. 241 */ 242 static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res) 243 { 244 /* 245 * We want to shortcut function call, but 246 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0. 247 */ 248 if (sizeof(unsigned long) == sizeof(unsigned long long) && 249 __alignof__(unsigned long) == __alignof__(unsigned long long)) 250 return kstrtoull(s, base, (unsigned long long *)res); 251 else 252 return _kstrtoul(s, base, res); 253 } 254 255 /** 256 * kstrtol - convert a string to a long 257 * @s: The start of the string. The string must be null-terminated, and may also 258 * include a single newline before its terminating null. The first character 259 * may also be a plus sign or a minus sign. 260 * @base: The number base to use. The maximum supported base is 16. If base is 261 * given as 0, then the base of the string is automatically detected with the 262 * conventional semantics - If it begins with 0x the number will be parsed as a 263 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 264 * parsed as an octal number. Otherwise it will be parsed as a decimal. 265 * @res: Where to write the result of the conversion on success. 266 * 267 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 268 * Used as a replacement for the obsolete simple_strtoull. Return code must 269 * be checked. 270 */ 271 static inline int __must_check kstrtol(const char *s, unsigned int base, long *res) 272 { 273 /* 274 * We want to shortcut function call, but 275 * __builtin_types_compatible_p(long, long long) = 0. 276 */ 277 if (sizeof(long) == sizeof(long long) && 278 __alignof__(long) == __alignof__(long long)) 279 return kstrtoll(s, base, (long long *)res); 280 else 281 return _kstrtol(s, base, res); 282 } 283 284 int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res); 285 int __must_check kstrtoint(const char *s, unsigned int base, int *res); 286 287 static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res) 288 { 289 return kstrtoull(s, base, res); 290 } 291 292 static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res) 293 { 294 return kstrtoll(s, base, res); 295 } 296 297 static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res) 298 { 299 return kstrtouint(s, base, res); 300 } 301 302 static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res) 303 { 304 return kstrtoint(s, base, res); 305 } 306 307 int __must_check kstrtou16(const char *s, unsigned int base, u16 *res); 308 int __must_check kstrtos16(const char *s, unsigned int base, s16 *res); 309 int __must_check kstrtou8(const char *s, unsigned int base, u8 *res); 310 int __must_check kstrtos8(const char *s, unsigned int base, s8 *res); 311 312 int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res); 313 int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res); 314 int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res); 315 int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res); 316 int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res); 317 int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res); 318 int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res); 319 int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res); 320 int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res); 321 int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res); 322 323 static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res) 324 { 325 return kstrtoull_from_user(s, count, base, res); 326 } 327 328 static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res) 329 { 330 return kstrtoll_from_user(s, count, base, res); 331 } 332 333 static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res) 334 { 335 return kstrtouint_from_user(s, count, base, res); 336 } 337 338 static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res) 339 { 340 return kstrtoint_from_user(s, count, base, res); 341 } 342 343 /* Obsolete, do not use. Use kstrto<foo> instead */ 344 345 extern unsigned long simple_strtoul(const char *,char **,unsigned int); 346 extern long simple_strtol(const char *,char **,unsigned int); 347 extern unsigned long long simple_strtoull(const char *,char **,unsigned int); 348 extern long long simple_strtoll(const char *,char **,unsigned int); 349 #define strict_strtoul kstrtoul 350 #define strict_strtol kstrtol 351 #define strict_strtoull kstrtoull 352 #define strict_strtoll kstrtoll 353 354 extern int num_to_str(char *buf, int size, unsigned long long num); 355 356 /* lib/printf utilities */ 357 358 extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...); 359 extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list); 360 extern __printf(3, 4) 361 int snprintf(char *buf, size_t size, const char *fmt, ...); 362 extern __printf(3, 0) 363 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args); 364 extern __printf(3, 4) 365 int scnprintf(char *buf, size_t size, const char *fmt, ...); 366 extern __printf(3, 0) 367 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args); 368 extern __printf(2, 3) 369 char *kasprintf(gfp_t gfp, const char *fmt, ...); 370 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args); 371 372 extern __scanf(2, 3) 373 int sscanf(const char *, const char *, ...); 374 extern __scanf(2, 0) 375 int vsscanf(const char *, const char *, va_list); 376 377 extern int get_option(char **str, int *pint); 378 extern char *get_options(const char *str, int nints, int *ints); 379 extern unsigned long long memparse(const char *ptr, char **retptr); 380 381 extern int core_kernel_text(unsigned long addr); 382 extern int core_kernel_data(unsigned long addr); 383 extern int __kernel_text_address(unsigned long addr); 384 extern int kernel_text_address(unsigned long addr); 385 extern int func_ptr_is_kernel_text(void *ptr); 386 387 struct pid; 388 extern struct pid *session_of_pgrp(struct pid *pgrp); 389 390 unsigned long int_sqrt(unsigned long); 391 392 extern void bust_spinlocks(int yes); 393 extern void wake_up_klogd(void); 394 extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */ 395 extern int panic_timeout; 396 extern int panic_on_oops; 397 extern int panic_on_unrecovered_nmi; 398 extern int panic_on_io_nmi; 399 extern int sysctl_panic_on_stackoverflow; 400 extern const char *print_tainted(void); 401 enum lockdep_ok { 402 LOCKDEP_STILL_OK, 403 LOCKDEP_NOW_UNRELIABLE 404 }; 405 extern void add_taint(unsigned flag, enum lockdep_ok); 406 extern int test_taint(unsigned flag); 407 extern unsigned long get_taint(void); 408 extern int root_mountflags; 409 410 extern bool early_boot_irqs_disabled; 411 412 /* Values used for system_state */ 413 extern enum system_states { 414 SYSTEM_BOOTING, 415 SYSTEM_RUNNING, 416 SYSTEM_HALT, 417 SYSTEM_POWER_OFF, 418 SYSTEM_RESTART, 419 } system_state; 420 421 #define TAINT_PROPRIETARY_MODULE 0 422 #define TAINT_FORCED_MODULE 1 423 #define TAINT_UNSAFE_SMP 2 424 #define TAINT_FORCED_RMMOD 3 425 #define TAINT_MACHINE_CHECK 4 426 #define TAINT_BAD_PAGE 5 427 #define TAINT_USER 6 428 #define TAINT_DIE 7 429 #define TAINT_OVERRIDDEN_ACPI_TABLE 8 430 #define TAINT_WARN 9 431 #define TAINT_CRAP 10 432 #define TAINT_FIRMWARE_WORKAROUND 11 433 #define TAINT_OOT_MODULE 12 434 435 extern const char hex_asc[]; 436 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)] 437 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4] 438 439 static inline char *hex_byte_pack(char *buf, u8 byte) 440 { 441 *buf++ = hex_asc_hi(byte); 442 *buf++ = hex_asc_lo(byte); 443 return buf; 444 } 445 446 static inline char * __deprecated pack_hex_byte(char *buf, u8 byte) 447 { 448 return hex_byte_pack(buf, byte); 449 } 450 451 extern int hex_to_bin(char ch); 452 extern int __must_check hex2bin(u8 *dst, const char *src, size_t count); 453 454 /* 455 * General tracing related utility functions - trace_printk(), 456 * tracing_on/tracing_off and tracing_start()/tracing_stop 457 * 458 * Use tracing_on/tracing_off when you want to quickly turn on or off 459 * tracing. It simply enables or disables the recording of the trace events. 460 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on 461 * file, which gives a means for the kernel and userspace to interact. 462 * Place a tracing_off() in the kernel where you want tracing to end. 463 * From user space, examine the trace, and then echo 1 > tracing_on 464 * to continue tracing. 465 * 466 * tracing_stop/tracing_start has slightly more overhead. It is used 467 * by things like suspend to ram where disabling the recording of the 468 * trace is not enough, but tracing must actually stop because things 469 * like calling smp_processor_id() may crash the system. 470 * 471 * Most likely, you want to use tracing_on/tracing_off. 472 */ 473 #ifdef CONFIG_RING_BUFFER 474 /* trace_off_permanent stops recording with no way to bring it back */ 475 void tracing_off_permanent(void); 476 #else 477 static inline void tracing_off_permanent(void) { } 478 #endif 479 480 enum ftrace_dump_mode { 481 DUMP_NONE, 482 DUMP_ALL, 483 DUMP_ORIG, 484 }; 485 486 #ifdef CONFIG_TRACING 487 void tracing_on(void); 488 void tracing_off(void); 489 int tracing_is_on(void); 490 491 extern void tracing_start(void); 492 extern void tracing_stop(void); 493 extern void ftrace_off_permanent(void); 494 495 static inline __printf(1, 2) 496 void ____trace_printk_check_format(const char *fmt, ...) 497 { 498 } 499 #define __trace_printk_check_format(fmt, args...) \ 500 do { \ 501 if (0) \ 502 ____trace_printk_check_format(fmt, ##args); \ 503 } while (0) 504 505 /** 506 * trace_printk - printf formatting in the ftrace buffer 507 * @fmt: the printf format for printing 508 * 509 * Note: __trace_printk is an internal function for trace_printk and 510 * the @ip is passed in via the trace_printk macro. 511 * 512 * This function allows a kernel developer to debug fast path sections 513 * that printk is not appropriate for. By scattering in various 514 * printk like tracing in the code, a developer can quickly see 515 * where problems are occurring. 516 * 517 * This is intended as a debugging tool for the developer only. 518 * Please refrain from leaving trace_printks scattered around in 519 * your code. 520 */ 521 522 #define trace_printk(fmt, args...) \ 523 do { \ 524 static const char *trace_printk_fmt \ 525 __attribute__((section("__trace_printk_fmt"))) = \ 526 __builtin_constant_p(fmt) ? fmt : NULL; \ 527 \ 528 __trace_printk_check_format(fmt, ##args); \ 529 \ 530 if (__builtin_constant_p(fmt)) \ 531 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \ 532 else \ 533 __trace_printk(_THIS_IP_, fmt, ##args); \ 534 } while (0) 535 536 extern __printf(2, 3) 537 int __trace_bprintk(unsigned long ip, const char *fmt, ...); 538 539 extern __printf(2, 3) 540 int __trace_printk(unsigned long ip, const char *fmt, ...); 541 542 extern void trace_dump_stack(void); 543 544 /* 545 * The double __builtin_constant_p is because gcc will give us an error 546 * if we try to allocate the static variable to fmt if it is not a 547 * constant. Even with the outer if statement. 548 */ 549 #define ftrace_vprintk(fmt, vargs) \ 550 do { \ 551 if (__builtin_constant_p(fmt)) { \ 552 static const char *trace_printk_fmt \ 553 __attribute__((section("__trace_printk_fmt"))) = \ 554 __builtin_constant_p(fmt) ? fmt : NULL; \ 555 \ 556 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \ 557 } else \ 558 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \ 559 } while (0) 560 561 extern int 562 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap); 563 564 extern int 565 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap); 566 567 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode); 568 #else 569 static inline void tracing_start(void) { } 570 static inline void tracing_stop(void) { } 571 static inline void ftrace_off_permanent(void) { } 572 static inline void trace_dump_stack(void) { } 573 574 static inline void tracing_on(void) { } 575 static inline void tracing_off(void) { } 576 static inline int tracing_is_on(void) { return 0; } 577 578 static inline __printf(1, 2) 579 int trace_printk(const char *fmt, ...) 580 { 581 return 0; 582 } 583 static inline int 584 ftrace_vprintk(const char *fmt, va_list ap) 585 { 586 return 0; 587 } 588 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } 589 #endif /* CONFIG_TRACING */ 590 591 /* 592 * min()/max()/clamp() macros that also do 593 * strict type-checking.. See the 594 * "unnecessary" pointer comparison. 595 */ 596 #define min(x, y) ({ \ 597 typeof(x) _min1 = (x); \ 598 typeof(y) _min2 = (y); \ 599 (void) (&_min1 == &_min2); \ 600 _min1 < _min2 ? _min1 : _min2; }) 601 602 #define max(x, y) ({ \ 603 typeof(x) _max1 = (x); \ 604 typeof(y) _max2 = (y); \ 605 (void) (&_max1 == &_max2); \ 606 _max1 > _max2 ? _max1 : _max2; }) 607 608 #define min3(x, y, z) ({ \ 609 typeof(x) _min1 = (x); \ 610 typeof(y) _min2 = (y); \ 611 typeof(z) _min3 = (z); \ 612 (void) (&_min1 == &_min2); \ 613 (void) (&_min1 == &_min3); \ 614 _min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \ 615 (_min2 < _min3 ? _min2 : _min3); }) 616 617 #define max3(x, y, z) ({ \ 618 typeof(x) _max1 = (x); \ 619 typeof(y) _max2 = (y); \ 620 typeof(z) _max3 = (z); \ 621 (void) (&_max1 == &_max2); \ 622 (void) (&_max1 == &_max3); \ 623 _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \ 624 (_max2 > _max3 ? _max2 : _max3); }) 625 626 /** 627 * min_not_zero - return the minimum that is _not_ zero, unless both are zero 628 * @x: value1 629 * @y: value2 630 */ 631 #define min_not_zero(x, y) ({ \ 632 typeof(x) __x = (x); \ 633 typeof(y) __y = (y); \ 634 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); }) 635 636 /** 637 * clamp - return a value clamped to a given range with strict typechecking 638 * @val: current value 639 * @min: minimum allowable value 640 * @max: maximum allowable value 641 * 642 * This macro does strict typechecking of min/max to make sure they are of the 643 * same type as val. See the unnecessary pointer comparisons. 644 */ 645 #define clamp(val, min, max) ({ \ 646 typeof(val) __val = (val); \ 647 typeof(min) __min = (min); \ 648 typeof(max) __max = (max); \ 649 (void) (&__val == &__min); \ 650 (void) (&__val == &__max); \ 651 __val = __val < __min ? __min: __val; \ 652 __val > __max ? __max: __val; }) 653 654 /* 655 * ..and if you can't take the strict 656 * types, you can specify one yourself. 657 * 658 * Or not use min/max/clamp at all, of course. 659 */ 660 #define min_t(type, x, y) ({ \ 661 type __min1 = (x); \ 662 type __min2 = (y); \ 663 __min1 < __min2 ? __min1: __min2; }) 664 665 #define max_t(type, x, y) ({ \ 666 type __max1 = (x); \ 667 type __max2 = (y); \ 668 __max1 > __max2 ? __max1: __max2; }) 669 670 /** 671 * clamp_t - return a value clamped to a given range using a given type 672 * @type: the type of variable to use 673 * @val: current value 674 * @min: minimum allowable value 675 * @max: maximum allowable value 676 * 677 * This macro does no typechecking and uses temporary variables of type 678 * 'type' to make all the comparisons. 679 */ 680 #define clamp_t(type, val, min, max) ({ \ 681 type __val = (val); \ 682 type __min = (min); \ 683 type __max = (max); \ 684 __val = __val < __min ? __min: __val; \ 685 __val > __max ? __max: __val; }) 686 687 /** 688 * clamp_val - return a value clamped to a given range using val's type 689 * @val: current value 690 * @min: minimum allowable value 691 * @max: maximum allowable value 692 * 693 * This macro does no typechecking and uses temporary variables of whatever 694 * type the input argument 'val' is. This is useful when val is an unsigned 695 * type and min and max are literals that will otherwise be assigned a signed 696 * integer type. 697 */ 698 #define clamp_val(val, min, max) ({ \ 699 typeof(val) __val = (val); \ 700 typeof(val) __min = (min); \ 701 typeof(val) __max = (max); \ 702 __val = __val < __min ? __min: __val; \ 703 __val > __max ? __max: __val; }) 704 705 706 /* 707 * swap - swap value of @a and @b 708 */ 709 #define swap(a, b) \ 710 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0) 711 712 /** 713 * container_of - cast a member of a structure out to the containing structure 714 * @ptr: the pointer to the member. 715 * @type: the type of the container struct this is embedded in. 716 * @member: the name of the member within the struct. 717 * 718 */ 719 #define container_of(ptr, type, member) ({ \ 720 const typeof( ((type *)0)->member ) *__mptr = (ptr); \ 721 (type *)( (char *)__mptr - offsetof(type,member) );}) 722 723 /* Trap pasters of __FUNCTION__ at compile-time */ 724 #define __FUNCTION__ (__func__) 725 726 /* This helps us to avoid #ifdef CONFIG_SYMBOL_PREFIX */ 727 #ifdef CONFIG_SYMBOL_PREFIX 728 #define SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX 729 #else 730 #define SYMBOL_PREFIX "" 731 #endif 732 733 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ 734 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 735 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD 736 #endif 737 738 extern int do_sysinfo(struct sysinfo *info); 739 740 #endif 741