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