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