1 #ifndef _LINUX_KERNEL_H 2 #define _LINUX_KERNEL_H 3 4 /* 5 * 'kernel.h' contains some often-used function prototypes etc 6 */ 7 #define __ALIGN_KERNEL(x, a) __ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1) 8 #define __ALIGN_KERNEL_MASK(x, mask) (((x) + (mask)) & ~(mask)) 9 10 #ifdef __KERNEL__ 11 12 #include <stdarg.h> 13 #include <linux/linkage.h> 14 #include <linux/stddef.h> 15 #include <linux/types.h> 16 #include <linux/compiler.h> 17 #include <linux/bitops.h> 18 #include <linux/log2.h> 19 #include <linux/typecheck.h> 20 #include <linux/printk.h> 21 #include <linux/dynamic_debug.h> 22 #include <asm/byteorder.h> 23 #include <asm/bug.h> 24 25 #define USHRT_MAX ((u16)(~0U)) 26 #define SHRT_MAX ((s16)(USHRT_MAX>>1)) 27 #define SHRT_MIN ((s16)(-SHRT_MAX - 1)) 28 #define INT_MAX ((int)(~0U>>1)) 29 #define INT_MIN (-INT_MAX - 1) 30 #define UINT_MAX (~0U) 31 #define LONG_MAX ((long)(~0UL>>1)) 32 #define LONG_MIN (-LONG_MAX - 1) 33 #define ULONG_MAX (~0UL) 34 #define LLONG_MAX ((long long)(~0ULL>>1)) 35 #define LLONG_MIN (-LLONG_MAX - 1) 36 #define ULLONG_MAX (~0ULL) 37 38 #define STACK_MAGIC 0xdeadbeef 39 40 #define ALIGN(x, a) __ALIGN_KERNEL((x), (a)) 41 #define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask)) 42 #define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a))) 43 #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0) 44 45 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr)) 46 47 /* 48 * This looks more complex than it should be. But we need to 49 * get the type for the ~ right in round_down (it needs to be 50 * as wide as the result!), and we want to evaluate the macro 51 * arguments just once each. 52 */ 53 #define __round_mask(x, y) ((__typeof__(x))((y)-1)) 54 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1) 55 #define round_down(x, y) ((x) & ~__round_mask(x, y)) 56 57 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f)) 58 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d)) 59 #define DIV_ROUND_UP_ULL(ll,d) \ 60 ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; }) 61 62 #if BITS_PER_LONG == 32 63 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d) 64 #else 65 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d) 66 #endif 67 68 /* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */ 69 #define roundup(x, y) ( \ 70 { \ 71 const typeof(y) __y = y; \ 72 (((x) + (__y - 1)) / __y) * __y; \ 73 } \ 74 ) 75 #define rounddown(x, y) ( \ 76 { \ 77 typeof(x) __x = (x); \ 78 __x - (__x % (y)); \ 79 } \ 80 ) 81 #define DIV_ROUND_CLOSEST(x, divisor)( \ 82 { \ 83 typeof(divisor) __divisor = divisor; \ 84 (((x) + ((__divisor) / 2)) / (__divisor)); \ 85 } \ 86 ) 87 88 /* 89 * Multiplies an integer by a fraction, while avoiding unnecessary 90 * overflow or loss of precision. 91 */ 92 #define mult_frac(x, numer, denom)( \ 93 { \ 94 typeof(x) quot = (x) / (denom); \ 95 typeof(x) rem = (x) % (denom); \ 96 (quot * (numer)) + ((rem * (numer)) / (denom)); \ 97 } \ 98 ) 99 100 101 #define _RET_IP_ (unsigned long)__builtin_return_address(0) 102 #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; }) 103 104 #ifdef CONFIG_LBDAF 105 # include <asm/div64.h> 106 # define sector_div(a, b) do_div(a, b) 107 #else 108 # define sector_div(n, b)( \ 109 { \ 110 int _res; \ 111 _res = (n) % (b); \ 112 (n) /= (b); \ 113 _res; \ 114 } \ 115 ) 116 #endif 117 118 /** 119 * upper_32_bits - return bits 32-63 of a number 120 * @n: the number we're accessing 121 * 122 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress 123 * the "right shift count >= width of type" warning when that quantity is 124 * 32-bits. 125 */ 126 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16)) 127 128 /** 129 * lower_32_bits - return bits 0-31 of a number 130 * @n: the number we're accessing 131 */ 132 #define lower_32_bits(n) ((u32)(n)) 133 134 struct completion; 135 struct pt_regs; 136 struct user; 137 138 #ifdef CONFIG_PREEMPT_VOLUNTARY 139 extern int _cond_resched(void); 140 # define might_resched() _cond_resched() 141 #else 142 # define might_resched() do { } while (0) 143 #endif 144 145 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 146 void __might_sleep(const char *file, int line, int preempt_offset); 147 /** 148 * might_sleep - annotation for functions that can sleep 149 * 150 * this macro will print a stack trace if it is executed in an atomic 151 * context (spinlock, irq-handler, ...). 152 * 153 * This is a useful debugging help to be able to catch problems early and not 154 * be bitten later when the calling function happens to sleep when it is not 155 * supposed to. 156 */ 157 # define might_sleep() \ 158 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0) 159 #else 160 static inline void __might_sleep(const char *file, int line, 161 int preempt_offset) { } 162 # define might_sleep() do { might_resched(); } while (0) 163 #endif 164 165 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0) 166 167 /* 168 * abs() handles unsigned and signed longs, ints, shorts and chars. For all 169 * input types abs() returns a signed long. 170 * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64() 171 * for those. 172 */ 173 #define abs(x) ({ \ 174 long ret; \ 175 if (sizeof(x) == sizeof(long)) { \ 176 long __x = (x); \ 177 ret = (__x < 0) ? -__x : __x; \ 178 } else { \ 179 int __x = (x); \ 180 ret = (__x < 0) ? -__x : __x; \ 181 } \ 182 ret; \ 183 }) 184 185 #define abs64(x) ({ \ 186 s64 __x = (x); \ 187 (__x < 0) ? -__x : __x; \ 188 }) 189 190 #ifdef CONFIG_PROVE_LOCKING 191 void might_fault(void); 192 #else 193 static inline void might_fault(void) 194 { 195 might_sleep(); 196 } 197 #endif 198 199 extern struct atomic_notifier_head panic_notifier_list; 200 extern long (*panic_blink)(int state); 201 __printf(1, 2) 202 void panic(const char *fmt, ...) 203 __noreturn __cold; 204 extern void oops_enter(void); 205 extern void oops_exit(void); 206 void print_oops_end_marker(void); 207 extern int oops_may_print(void); 208 void do_exit(long error_code) 209 __noreturn; 210 void complete_and_exit(struct completion *, long) 211 __noreturn; 212 213 /* Internal, do not use. */ 214 int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res); 215 int __must_check _kstrtol(const char *s, unsigned int base, long *res); 216 217 int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res); 218 int __must_check kstrtoll(const char *s, unsigned int base, long long *res); 219 static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res) 220 { 221 /* 222 * We want to shortcut function call, but 223 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0. 224 */ 225 if (sizeof(unsigned long) == sizeof(unsigned long long) && 226 __alignof__(unsigned long) == __alignof__(unsigned long long)) 227 return kstrtoull(s, base, (unsigned long long *)res); 228 else 229 return _kstrtoul(s, base, res); 230 } 231 232 static inline int __must_check kstrtol(const char *s, unsigned int base, long *res) 233 { 234 /* 235 * We want to shortcut function call, but 236 * __builtin_types_compatible_p(long, long long) = 0. 237 */ 238 if (sizeof(long) == sizeof(long long) && 239 __alignof__(long) == __alignof__(long long)) 240 return kstrtoll(s, base, (long long *)res); 241 else 242 return _kstrtol(s, base, res); 243 } 244 245 int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res); 246 int __must_check kstrtoint(const char *s, unsigned int base, int *res); 247 248 static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res) 249 { 250 return kstrtoull(s, base, res); 251 } 252 253 static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res) 254 { 255 return kstrtoll(s, base, res); 256 } 257 258 static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res) 259 { 260 return kstrtouint(s, base, res); 261 } 262 263 static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res) 264 { 265 return kstrtoint(s, base, res); 266 } 267 268 int __must_check kstrtou16(const char *s, unsigned int base, u16 *res); 269 int __must_check kstrtos16(const char *s, unsigned int base, s16 *res); 270 int __must_check kstrtou8(const char *s, unsigned int base, u8 *res); 271 int __must_check kstrtos8(const char *s, unsigned int base, s8 *res); 272 273 int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res); 274 int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res); 275 int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res); 276 int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res); 277 int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res); 278 int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res); 279 int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res); 280 int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res); 281 int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res); 282 int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res); 283 284 static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res) 285 { 286 return kstrtoull_from_user(s, count, base, res); 287 } 288 289 static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res) 290 { 291 return kstrtoll_from_user(s, count, base, res); 292 } 293 294 static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res) 295 { 296 return kstrtouint_from_user(s, count, base, res); 297 } 298 299 static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res) 300 { 301 return kstrtoint_from_user(s, count, base, res); 302 } 303 304 /* Obsolete, do not use. Use kstrto<foo> instead */ 305 306 extern unsigned long simple_strtoul(const char *,char **,unsigned int); 307 extern long simple_strtol(const char *,char **,unsigned int); 308 extern unsigned long long simple_strtoull(const char *,char **,unsigned int); 309 extern long long simple_strtoll(const char *,char **,unsigned int); 310 #define strict_strtoul kstrtoul 311 #define strict_strtol kstrtol 312 #define strict_strtoull kstrtoull 313 #define strict_strtoll kstrtoll 314 315 /* lib/printf utilities */ 316 317 extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...); 318 extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list); 319 extern __printf(3, 4) 320 int snprintf(char *buf, size_t size, const char *fmt, ...); 321 extern __printf(3, 0) 322 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args); 323 extern __printf(3, 4) 324 int scnprintf(char *buf, size_t size, const char *fmt, ...); 325 extern __printf(3, 0) 326 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args); 327 extern __printf(2, 3) 328 char *kasprintf(gfp_t gfp, const char *fmt, ...); 329 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args); 330 331 extern int sscanf(const char *, const char *, ...) 332 __attribute__ ((format (scanf, 2, 3))); 333 extern int vsscanf(const char *, const char *, va_list) 334 __attribute__ ((format (scanf, 2, 0))); 335 336 extern int get_option(char **str, int *pint); 337 extern char *get_options(const char *str, int nints, int *ints); 338 extern unsigned long long memparse(const char *ptr, char **retptr); 339 340 extern int core_kernel_text(unsigned long addr); 341 extern int core_kernel_data(unsigned long addr); 342 extern int __kernel_text_address(unsigned long addr); 343 extern int kernel_text_address(unsigned long addr); 344 extern int func_ptr_is_kernel_text(void *ptr); 345 346 struct pid; 347 extern struct pid *session_of_pgrp(struct pid *pgrp); 348 349 unsigned long int_sqrt(unsigned long); 350 351 extern void bust_spinlocks(int yes); 352 extern void wake_up_klogd(void); 353 extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */ 354 extern int panic_timeout; 355 extern int panic_on_oops; 356 extern int panic_on_unrecovered_nmi; 357 extern int panic_on_io_nmi; 358 extern int sysctl_panic_on_stackoverflow; 359 extern const char *print_tainted(void); 360 extern void add_taint(unsigned flag); 361 extern int test_taint(unsigned flag); 362 extern unsigned long get_taint(void); 363 extern int root_mountflags; 364 365 extern bool early_boot_irqs_disabled; 366 367 /* Values used for system_state */ 368 extern enum system_states { 369 SYSTEM_BOOTING, 370 SYSTEM_RUNNING, 371 SYSTEM_HALT, 372 SYSTEM_POWER_OFF, 373 SYSTEM_RESTART, 374 SYSTEM_SUSPEND_DISK, 375 } system_state; 376 377 #define TAINT_PROPRIETARY_MODULE 0 378 #define TAINT_FORCED_MODULE 1 379 #define TAINT_UNSAFE_SMP 2 380 #define TAINT_FORCED_RMMOD 3 381 #define TAINT_MACHINE_CHECK 4 382 #define TAINT_BAD_PAGE 5 383 #define TAINT_USER 6 384 #define TAINT_DIE 7 385 #define TAINT_OVERRIDDEN_ACPI_TABLE 8 386 #define TAINT_WARN 9 387 #define TAINT_CRAP 10 388 #define TAINT_FIRMWARE_WORKAROUND 11 389 #define TAINT_OOT_MODULE 12 390 391 extern const char hex_asc[]; 392 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)] 393 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4] 394 395 static inline char *hex_byte_pack(char *buf, u8 byte) 396 { 397 *buf++ = hex_asc_hi(byte); 398 *buf++ = hex_asc_lo(byte); 399 return buf; 400 } 401 402 static inline char * __deprecated pack_hex_byte(char *buf, u8 byte) 403 { 404 return hex_byte_pack(buf, byte); 405 } 406 407 extern int hex_to_bin(char ch); 408 extern int __must_check hex2bin(u8 *dst, const char *src, size_t count); 409 410 /* 411 * General tracing related utility functions - trace_printk(), 412 * tracing_on/tracing_off and tracing_start()/tracing_stop 413 * 414 * Use tracing_on/tracing_off when you want to quickly turn on or off 415 * tracing. It simply enables or disables the recording of the trace events. 416 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on 417 * file, which gives a means for the kernel and userspace to interact. 418 * Place a tracing_off() in the kernel where you want tracing to end. 419 * From user space, examine the trace, and then echo 1 > tracing_on 420 * to continue tracing. 421 * 422 * tracing_stop/tracing_start has slightly more overhead. It is used 423 * by things like suspend to ram where disabling the recording of the 424 * trace is not enough, but tracing must actually stop because things 425 * like calling smp_processor_id() may crash the system. 426 * 427 * Most likely, you want to use tracing_on/tracing_off. 428 */ 429 #ifdef CONFIG_RING_BUFFER 430 void tracing_on(void); 431 void tracing_off(void); 432 /* trace_off_permanent stops recording with no way to bring it back */ 433 void tracing_off_permanent(void); 434 int tracing_is_on(void); 435 #else 436 static inline void tracing_on(void) { } 437 static inline void tracing_off(void) { } 438 static inline void tracing_off_permanent(void) { } 439 static inline int tracing_is_on(void) { return 0; } 440 #endif 441 442 enum ftrace_dump_mode { 443 DUMP_NONE, 444 DUMP_ALL, 445 DUMP_ORIG, 446 }; 447 448 #ifdef CONFIG_TRACING 449 extern void tracing_start(void); 450 extern void tracing_stop(void); 451 extern void ftrace_off_permanent(void); 452 453 static inline __printf(1, 2) 454 void ____trace_printk_check_format(const char *fmt, ...) 455 { 456 } 457 #define __trace_printk_check_format(fmt, args...) \ 458 do { \ 459 if (0) \ 460 ____trace_printk_check_format(fmt, ##args); \ 461 } while (0) 462 463 /** 464 * trace_printk - printf formatting in the ftrace buffer 465 * @fmt: the printf format for printing 466 * 467 * Note: __trace_printk is an internal function for trace_printk and 468 * the @ip is passed in via the trace_printk macro. 469 * 470 * This function allows a kernel developer to debug fast path sections 471 * that printk is not appropriate for. By scattering in various 472 * printk like tracing in the code, a developer can quickly see 473 * where problems are occurring. 474 * 475 * This is intended as a debugging tool for the developer only. 476 * Please refrain from leaving trace_printks scattered around in 477 * your code. 478 */ 479 480 #define trace_printk(fmt, args...) \ 481 do { \ 482 __trace_printk_check_format(fmt, ##args); \ 483 if (__builtin_constant_p(fmt)) { \ 484 static const char *trace_printk_fmt \ 485 __attribute__((section("__trace_printk_fmt"))) = \ 486 __builtin_constant_p(fmt) ? fmt : NULL; \ 487 \ 488 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \ 489 } else \ 490 __trace_printk(_THIS_IP_, fmt, ##args); \ 491 } while (0) 492 493 extern __printf(2, 3) 494 int __trace_bprintk(unsigned long ip, const char *fmt, ...); 495 496 extern __printf(2, 3) 497 int __trace_printk(unsigned long ip, const char *fmt, ...); 498 499 extern void trace_dump_stack(void); 500 501 /* 502 * The double __builtin_constant_p is because gcc will give us an error 503 * if we try to allocate the static variable to fmt if it is not a 504 * constant. Even with the outer if statement. 505 */ 506 #define ftrace_vprintk(fmt, vargs) \ 507 do { \ 508 if (__builtin_constant_p(fmt)) { \ 509 static const char *trace_printk_fmt \ 510 __attribute__((section("__trace_printk_fmt"))) = \ 511 __builtin_constant_p(fmt) ? fmt : NULL; \ 512 \ 513 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \ 514 } else \ 515 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \ 516 } while (0) 517 518 extern int 519 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap); 520 521 extern int 522 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap); 523 524 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode); 525 #else 526 static inline __printf(1, 2) 527 int trace_printk(const char *fmt, ...); 528 529 static inline void tracing_start(void) { } 530 static inline void tracing_stop(void) { } 531 static inline void ftrace_off_permanent(void) { } 532 static inline void trace_dump_stack(void) { } 533 static inline int 534 trace_printk(const char *fmt, ...) 535 { 536 return 0; 537 } 538 static inline int 539 ftrace_vprintk(const char *fmt, va_list ap) 540 { 541 return 0; 542 } 543 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } 544 #endif /* CONFIG_TRACING */ 545 546 /* 547 * min()/max()/clamp() macros that also do 548 * strict type-checking.. See the 549 * "unnecessary" pointer comparison. 550 */ 551 #define min(x, y) ({ \ 552 typeof(x) _min1 = (x); \ 553 typeof(y) _min2 = (y); \ 554 (void) (&_min1 == &_min2); \ 555 _min1 < _min2 ? _min1 : _min2; }) 556 557 #define max(x, y) ({ \ 558 typeof(x) _max1 = (x); \ 559 typeof(y) _max2 = (y); \ 560 (void) (&_max1 == &_max2); \ 561 _max1 > _max2 ? _max1 : _max2; }) 562 563 #define min3(x, y, z) ({ \ 564 typeof(x) _min1 = (x); \ 565 typeof(y) _min2 = (y); \ 566 typeof(z) _min3 = (z); \ 567 (void) (&_min1 == &_min2); \ 568 (void) (&_min1 == &_min3); \ 569 _min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \ 570 (_min2 < _min3 ? _min2 : _min3); }) 571 572 #define max3(x, y, z) ({ \ 573 typeof(x) _max1 = (x); \ 574 typeof(y) _max2 = (y); \ 575 typeof(z) _max3 = (z); \ 576 (void) (&_max1 == &_max2); \ 577 (void) (&_max1 == &_max3); \ 578 _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \ 579 (_max2 > _max3 ? _max2 : _max3); }) 580 581 /** 582 * min_not_zero - return the minimum that is _not_ zero, unless both are zero 583 * @x: value1 584 * @y: value2 585 */ 586 #define min_not_zero(x, y) ({ \ 587 typeof(x) __x = (x); \ 588 typeof(y) __y = (y); \ 589 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); }) 590 591 /** 592 * clamp - return a value clamped to a given range with strict typechecking 593 * @val: current value 594 * @min: minimum allowable value 595 * @max: maximum allowable value 596 * 597 * This macro does strict typechecking of min/max to make sure they are of the 598 * same type as val. See the unnecessary pointer comparisons. 599 */ 600 #define clamp(val, min, max) ({ \ 601 typeof(val) __val = (val); \ 602 typeof(min) __min = (min); \ 603 typeof(max) __max = (max); \ 604 (void) (&__val == &__min); \ 605 (void) (&__val == &__max); \ 606 __val = __val < __min ? __min: __val; \ 607 __val > __max ? __max: __val; }) 608 609 /* 610 * ..and if you can't take the strict 611 * types, you can specify one yourself. 612 * 613 * Or not use min/max/clamp at all, of course. 614 */ 615 #define min_t(type, x, y) ({ \ 616 type __min1 = (x); \ 617 type __min2 = (y); \ 618 __min1 < __min2 ? __min1: __min2; }) 619 620 #define max_t(type, x, y) ({ \ 621 type __max1 = (x); \ 622 type __max2 = (y); \ 623 __max1 > __max2 ? __max1: __max2; }) 624 625 /** 626 * clamp_t - return a value clamped to a given range using a given type 627 * @type: the type of variable to use 628 * @val: current value 629 * @min: minimum allowable value 630 * @max: maximum allowable value 631 * 632 * This macro does no typechecking and uses temporary variables of type 633 * 'type' to make all the comparisons. 634 */ 635 #define clamp_t(type, val, min, max) ({ \ 636 type __val = (val); \ 637 type __min = (min); \ 638 type __max = (max); \ 639 __val = __val < __min ? __min: __val; \ 640 __val > __max ? __max: __val; }) 641 642 /** 643 * clamp_val - return a value clamped to a given range using val's type 644 * @val: current value 645 * @min: minimum allowable value 646 * @max: maximum allowable value 647 * 648 * This macro does no typechecking and uses temporary variables of whatever 649 * type the input argument 'val' is. This is useful when val is an unsigned 650 * type and min and max are literals that will otherwise be assigned a signed 651 * integer type. 652 */ 653 #define clamp_val(val, min, max) ({ \ 654 typeof(val) __val = (val); \ 655 typeof(val) __min = (min); \ 656 typeof(val) __max = (max); \ 657 __val = __val < __min ? __min: __val; \ 658 __val > __max ? __max: __val; }) 659 660 661 /* 662 * swap - swap value of @a and @b 663 */ 664 #define swap(a, b) \ 665 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0) 666 667 /** 668 * container_of - cast a member of a structure out to the containing structure 669 * @ptr: the pointer to the member. 670 * @type: the type of the container struct this is embedded in. 671 * @member: the name of the member within the struct. 672 * 673 */ 674 #define container_of(ptr, type, member) ({ \ 675 const typeof( ((type *)0)->member ) *__mptr = (ptr); \ 676 (type *)( (char *)__mptr - offsetof(type,member) );}) 677 678 #ifdef __CHECKER__ 679 #define BUILD_BUG_ON_NOT_POWER_OF_2(n) 680 #define BUILD_BUG_ON_ZERO(e) (0) 681 #define BUILD_BUG_ON_NULL(e) ((void*)0) 682 #define BUILD_BUG_ON(condition) 683 #define BUILD_BUG() (0) 684 #else /* __CHECKER__ */ 685 686 /* Force a compilation error if a constant expression is not a power of 2 */ 687 #define BUILD_BUG_ON_NOT_POWER_OF_2(n) \ 688 BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0)) 689 690 /* Force a compilation error if condition is true, but also produce a 691 result (of value 0 and type size_t), so the expression can be used 692 e.g. in a structure initializer (or where-ever else comma expressions 693 aren't permitted). */ 694 #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); })) 695 #define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); })) 696 697 /** 698 * BUILD_BUG_ON - break compile if a condition is true. 699 * @condition: the condition which the compiler should know is false. 700 * 701 * If you have some code which relies on certain constants being equal, or 702 * other compile-time-evaluated condition, you should use BUILD_BUG_ON to 703 * detect if someone changes it. 704 * 705 * The implementation uses gcc's reluctance to create a negative array, but 706 * gcc (as of 4.4) only emits that error for obvious cases (eg. not arguments 707 * to inline functions). So as a fallback we use the optimizer; if it can't 708 * prove the condition is false, it will cause a link error on the undefined 709 * "__build_bug_on_failed". This error message can be harder to track down 710 * though, hence the two different methods. 711 */ 712 #ifndef __OPTIMIZE__ 713 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)])) 714 #else 715 extern int __build_bug_on_failed; 716 #define BUILD_BUG_ON(condition) \ 717 do { \ 718 ((void)sizeof(char[1 - 2*!!(condition)])); \ 719 if (condition) __build_bug_on_failed = 1; \ 720 } while(0) 721 #endif 722 723 /** 724 * BUILD_BUG - break compile if used. 725 * 726 * If you have some code that you expect the compiler to eliminate at 727 * build time, you should use BUILD_BUG to detect if it is 728 * unexpectedly used. 729 */ 730 #define BUILD_BUG() \ 731 do { \ 732 extern void __build_bug_failed(void) \ 733 __linktime_error("BUILD_BUG failed"); \ 734 __build_bug_failed(); \ 735 } while (0) 736 737 #endif /* __CHECKER__ */ 738 739 /* Trap pasters of __FUNCTION__ at compile-time */ 740 #define __FUNCTION__ (__func__) 741 742 /* This helps us to avoid #ifdef CONFIG_NUMA */ 743 #ifdef CONFIG_NUMA 744 #define NUMA_BUILD 1 745 #else 746 #define NUMA_BUILD 0 747 #endif 748 749 /* This helps us avoid #ifdef CONFIG_COMPACTION */ 750 #ifdef CONFIG_COMPACTION 751 #define COMPACTION_BUILD 1 752 #else 753 #define COMPACTION_BUILD 0 754 #endif 755 756 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ 757 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 758 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD 759 #endif 760 761 struct sysinfo; 762 extern int do_sysinfo(struct sysinfo *info); 763 764 #endif /* __KERNEL__ */ 765 766 #define SI_LOAD_SHIFT 16 767 struct sysinfo { 768 long uptime; /* Seconds since boot */ 769 unsigned long loads[3]; /* 1, 5, and 15 minute load averages */ 770 unsigned long totalram; /* Total usable main memory size */ 771 unsigned long freeram; /* Available memory size */ 772 unsigned long sharedram; /* Amount of shared memory */ 773 unsigned long bufferram; /* Memory used by buffers */ 774 unsigned long totalswap; /* Total swap space size */ 775 unsigned long freeswap; /* swap space still available */ 776 unsigned short procs; /* Number of current processes */ 777 unsigned short pad; /* explicit padding for m68k */ 778 unsigned long totalhigh; /* Total high memory size */ 779 unsigned long freehigh; /* Available high memory size */ 780 unsigned int mem_unit; /* Memory unit size in bytes */ 781 char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */ 782 }; 783 784 #endif 785