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 extern unsigned long simple_strtoul(const char *,char **,unsigned int); 291 extern long simple_strtol(const char *,char **,unsigned int); 292 extern unsigned long long simple_strtoull(const char *,char **,unsigned int); 293 extern long long simple_strtoll(const char *,char **,unsigned int); 294 #define strict_strtoul kstrtoul 295 #define strict_strtol kstrtol 296 #define strict_strtoull kstrtoull 297 #define strict_strtoll kstrtoll 298 299 extern int sprintf(char * buf, const char * fmt, ...) 300 __attribute__ ((format (printf, 2, 3))); 301 extern int vsprintf(char *buf, const char *, va_list) 302 __attribute__ ((format (printf, 2, 0))); 303 extern int snprintf(char * buf, size_t size, const char * fmt, ...) 304 __attribute__ ((format (printf, 3, 4))); 305 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) 306 __attribute__ ((format (printf, 3, 0))); 307 extern int scnprintf(char * buf, size_t size, const char * fmt, ...) 308 __attribute__ ((format (printf, 3, 4))); 309 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args) 310 __attribute__ ((format (printf, 3, 0))); 311 extern char *kasprintf(gfp_t gfp, const char *fmt, ...) 312 __attribute__ ((format (printf, 2, 3))); 313 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args); 314 315 extern int sscanf(const char *, const char *, ...) 316 __attribute__ ((format (scanf, 2, 3))); 317 extern int vsscanf(const char *, const char *, va_list) 318 __attribute__ ((format (scanf, 2, 0))); 319 320 extern int get_option(char **str, int *pint); 321 extern char *get_options(const char *str, int nints, int *ints); 322 extern unsigned long long memparse(const char *ptr, char **retptr); 323 324 extern int core_kernel_text(unsigned long addr); 325 extern int core_kernel_data(unsigned long addr); 326 extern int __kernel_text_address(unsigned long addr); 327 extern int kernel_text_address(unsigned long addr); 328 extern int func_ptr_is_kernel_text(void *ptr); 329 330 struct pid; 331 extern struct pid *session_of_pgrp(struct pid *pgrp); 332 333 unsigned long int_sqrt(unsigned long); 334 335 extern void bust_spinlocks(int yes); 336 extern void wake_up_klogd(void); 337 extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */ 338 extern int panic_timeout; 339 extern int panic_on_oops; 340 extern int panic_on_unrecovered_nmi; 341 extern int panic_on_io_nmi; 342 extern const char *print_tainted(void); 343 extern void add_taint(unsigned flag); 344 extern int test_taint(unsigned flag); 345 extern unsigned long get_taint(void); 346 extern int root_mountflags; 347 348 extern bool early_boot_irqs_disabled; 349 350 /* Values used for system_state */ 351 extern enum system_states { 352 SYSTEM_BOOTING, 353 SYSTEM_RUNNING, 354 SYSTEM_HALT, 355 SYSTEM_POWER_OFF, 356 SYSTEM_RESTART, 357 SYSTEM_SUSPEND_DISK, 358 } system_state; 359 360 #define TAINT_PROPRIETARY_MODULE 0 361 #define TAINT_FORCED_MODULE 1 362 #define TAINT_UNSAFE_SMP 2 363 #define TAINT_FORCED_RMMOD 3 364 #define TAINT_MACHINE_CHECK 4 365 #define TAINT_BAD_PAGE 5 366 #define TAINT_USER 6 367 #define TAINT_DIE 7 368 #define TAINT_OVERRIDDEN_ACPI_TABLE 8 369 #define TAINT_WARN 9 370 #define TAINT_CRAP 10 371 #define TAINT_FIRMWARE_WORKAROUND 11 372 373 extern const char hex_asc[]; 374 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)] 375 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4] 376 377 static inline char *pack_hex_byte(char *buf, u8 byte) 378 { 379 *buf++ = hex_asc_hi(byte); 380 *buf++ = hex_asc_lo(byte); 381 return buf; 382 } 383 384 extern int hex_to_bin(char ch); 385 extern void hex2bin(u8 *dst, const char *src, size_t count); 386 387 /* 388 * General tracing related utility functions - trace_printk(), 389 * tracing_on/tracing_off and tracing_start()/tracing_stop 390 * 391 * Use tracing_on/tracing_off when you want to quickly turn on or off 392 * tracing. It simply enables or disables the recording of the trace events. 393 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on 394 * file, which gives a means for the kernel and userspace to interact. 395 * Place a tracing_off() in the kernel where you want tracing to end. 396 * From user space, examine the trace, and then echo 1 > tracing_on 397 * to continue tracing. 398 * 399 * tracing_stop/tracing_start has slightly more overhead. It is used 400 * by things like suspend to ram where disabling the recording of the 401 * trace is not enough, but tracing must actually stop because things 402 * like calling smp_processor_id() may crash the system. 403 * 404 * Most likely, you want to use tracing_on/tracing_off. 405 */ 406 #ifdef CONFIG_RING_BUFFER 407 void tracing_on(void); 408 void tracing_off(void); 409 /* trace_off_permanent stops recording with no way to bring it back */ 410 void tracing_off_permanent(void); 411 int tracing_is_on(void); 412 #else 413 static inline void tracing_on(void) { } 414 static inline void tracing_off(void) { } 415 static inline void tracing_off_permanent(void) { } 416 static inline int tracing_is_on(void) { return 0; } 417 #endif 418 419 enum ftrace_dump_mode { 420 DUMP_NONE, 421 DUMP_ALL, 422 DUMP_ORIG, 423 }; 424 425 #ifdef CONFIG_TRACING 426 extern void tracing_start(void); 427 extern void tracing_stop(void); 428 extern void ftrace_off_permanent(void); 429 430 static inline void __attribute__ ((format (printf, 1, 2))) 431 ____trace_printk_check_format(const char *fmt, ...) 432 { 433 } 434 #define __trace_printk_check_format(fmt, args...) \ 435 do { \ 436 if (0) \ 437 ____trace_printk_check_format(fmt, ##args); \ 438 } while (0) 439 440 /** 441 * trace_printk - printf formatting in the ftrace buffer 442 * @fmt: the printf format for printing 443 * 444 * Note: __trace_printk is an internal function for trace_printk and 445 * the @ip is passed in via the trace_printk macro. 446 * 447 * This function allows a kernel developer to debug fast path sections 448 * that printk is not appropriate for. By scattering in various 449 * printk like tracing in the code, a developer can quickly see 450 * where problems are occurring. 451 * 452 * This is intended as a debugging tool for the developer only. 453 * Please refrain from leaving trace_printks scattered around in 454 * your code. 455 */ 456 457 #define trace_printk(fmt, args...) \ 458 do { \ 459 __trace_printk_check_format(fmt, ##args); \ 460 if (__builtin_constant_p(fmt)) { \ 461 static const char *trace_printk_fmt \ 462 __attribute__((section("__trace_printk_fmt"))) = \ 463 __builtin_constant_p(fmt) ? fmt : NULL; \ 464 \ 465 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \ 466 } else \ 467 __trace_printk(_THIS_IP_, fmt, ##args); \ 468 } while (0) 469 470 extern int 471 __trace_bprintk(unsigned long ip, const char *fmt, ...) 472 __attribute__ ((format (printf, 2, 3))); 473 474 extern int 475 __trace_printk(unsigned long ip, const char *fmt, ...) 476 __attribute__ ((format (printf, 2, 3))); 477 478 extern void trace_dump_stack(void); 479 480 /* 481 * The double __builtin_constant_p is because gcc will give us an error 482 * if we try to allocate the static variable to fmt if it is not a 483 * constant. Even with the outer if statement. 484 */ 485 #define ftrace_vprintk(fmt, vargs) \ 486 do { \ 487 if (__builtin_constant_p(fmt)) { \ 488 static const char *trace_printk_fmt \ 489 __attribute__((section("__trace_printk_fmt"))) = \ 490 __builtin_constant_p(fmt) ? fmt : NULL; \ 491 \ 492 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \ 493 } else \ 494 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \ 495 } while (0) 496 497 extern int 498 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap); 499 500 extern int 501 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap); 502 503 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode); 504 #else 505 static inline int 506 trace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2))); 507 508 static inline void tracing_start(void) { } 509 static inline void tracing_stop(void) { } 510 static inline void ftrace_off_permanent(void) { } 511 static inline void trace_dump_stack(void) { } 512 static inline int 513 trace_printk(const char *fmt, ...) 514 { 515 return 0; 516 } 517 static inline int 518 ftrace_vprintk(const char *fmt, va_list ap) 519 { 520 return 0; 521 } 522 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } 523 #endif /* CONFIG_TRACING */ 524 525 /* 526 * min()/max()/clamp() macros that also do 527 * strict type-checking.. See the 528 * "unnecessary" pointer comparison. 529 */ 530 #define min(x, y) ({ \ 531 typeof(x) _min1 = (x); \ 532 typeof(y) _min2 = (y); \ 533 (void) (&_min1 == &_min2); \ 534 _min1 < _min2 ? _min1 : _min2; }) 535 536 #define max(x, y) ({ \ 537 typeof(x) _max1 = (x); \ 538 typeof(y) _max2 = (y); \ 539 (void) (&_max1 == &_max2); \ 540 _max1 > _max2 ? _max1 : _max2; }) 541 542 #define min3(x, y, z) ({ \ 543 typeof(x) _min1 = (x); \ 544 typeof(y) _min2 = (y); \ 545 typeof(z) _min3 = (z); \ 546 (void) (&_min1 == &_min2); \ 547 (void) (&_min1 == &_min3); \ 548 _min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \ 549 (_min2 < _min3 ? _min2 : _min3); }) 550 551 #define max3(x, y, z) ({ \ 552 typeof(x) _max1 = (x); \ 553 typeof(y) _max2 = (y); \ 554 typeof(z) _max3 = (z); \ 555 (void) (&_max1 == &_max2); \ 556 (void) (&_max1 == &_max3); \ 557 _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \ 558 (_max2 > _max3 ? _max2 : _max3); }) 559 560 /** 561 * min_not_zero - return the minimum that is _not_ zero, unless both are zero 562 * @x: value1 563 * @y: value2 564 */ 565 #define min_not_zero(x, y) ({ \ 566 typeof(x) __x = (x); \ 567 typeof(y) __y = (y); \ 568 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); }) 569 570 /** 571 * clamp - return a value clamped to a given range with strict typechecking 572 * @val: current value 573 * @min: minimum allowable value 574 * @max: maximum allowable value 575 * 576 * This macro does strict typechecking of min/max to make sure they are of the 577 * same type as val. See the unnecessary pointer comparisons. 578 */ 579 #define clamp(val, min, max) ({ \ 580 typeof(val) __val = (val); \ 581 typeof(min) __min = (min); \ 582 typeof(max) __max = (max); \ 583 (void) (&__val == &__min); \ 584 (void) (&__val == &__max); \ 585 __val = __val < __min ? __min: __val; \ 586 __val > __max ? __max: __val; }) 587 588 /* 589 * ..and if you can't take the strict 590 * types, you can specify one yourself. 591 * 592 * Or not use min/max/clamp at all, of course. 593 */ 594 #define min_t(type, x, y) ({ \ 595 type __min1 = (x); \ 596 type __min2 = (y); \ 597 __min1 < __min2 ? __min1: __min2; }) 598 599 #define max_t(type, x, y) ({ \ 600 type __max1 = (x); \ 601 type __max2 = (y); \ 602 __max1 > __max2 ? __max1: __max2; }) 603 604 /** 605 * clamp_t - return a value clamped to a given range using a given type 606 * @type: the type of variable to use 607 * @val: current value 608 * @min: minimum allowable value 609 * @max: maximum allowable value 610 * 611 * This macro does no typechecking and uses temporary variables of type 612 * 'type' to make all the comparisons. 613 */ 614 #define clamp_t(type, val, min, max) ({ \ 615 type __val = (val); \ 616 type __min = (min); \ 617 type __max = (max); \ 618 __val = __val < __min ? __min: __val; \ 619 __val > __max ? __max: __val; }) 620 621 /** 622 * clamp_val - return a value clamped to a given range using val's type 623 * @val: current value 624 * @min: minimum allowable value 625 * @max: maximum allowable value 626 * 627 * This macro does no typechecking and uses temporary variables of whatever 628 * type the input argument 'val' is. This is useful when val is an unsigned 629 * type and min and max are literals that will otherwise be assigned a signed 630 * integer type. 631 */ 632 #define clamp_val(val, min, max) ({ \ 633 typeof(val) __val = (val); \ 634 typeof(val) __min = (min); \ 635 typeof(val) __max = (max); \ 636 __val = __val < __min ? __min: __val; \ 637 __val > __max ? __max: __val; }) 638 639 640 /* 641 * swap - swap value of @a and @b 642 */ 643 #define swap(a, b) \ 644 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0) 645 646 /** 647 * container_of - cast a member of a structure out to the containing structure 648 * @ptr: the pointer to the member. 649 * @type: the type of the container struct this is embedded in. 650 * @member: the name of the member within the struct. 651 * 652 */ 653 #define container_of(ptr, type, member) ({ \ 654 const typeof( ((type *)0)->member ) *__mptr = (ptr); \ 655 (type *)( (char *)__mptr - offsetof(type,member) );}) 656 657 #ifdef __CHECKER__ 658 #define BUILD_BUG_ON_NOT_POWER_OF_2(n) 659 #define BUILD_BUG_ON_ZERO(e) (0) 660 #define BUILD_BUG_ON_NULL(e) ((void*)0) 661 #define BUILD_BUG_ON(condition) 662 #else /* __CHECKER__ */ 663 664 /* Force a compilation error if a constant expression is not a power of 2 */ 665 #define BUILD_BUG_ON_NOT_POWER_OF_2(n) \ 666 BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0)) 667 668 /* Force a compilation error if condition is true, but also produce a 669 result (of value 0 and type size_t), so the expression can be used 670 e.g. in a structure initializer (or where-ever else comma expressions 671 aren't permitted). */ 672 #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); })) 673 #define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); })) 674 675 /** 676 * BUILD_BUG_ON - break compile if a condition is true. 677 * @condition: the condition which the compiler should know is false. 678 * 679 * If you have some code which relies on certain constants being equal, or 680 * other compile-time-evaluated condition, you should use BUILD_BUG_ON to 681 * detect if someone changes it. 682 * 683 * The implementation uses gcc's reluctance to create a negative array, but 684 * gcc (as of 4.4) only emits that error for obvious cases (eg. not arguments 685 * to inline functions). So as a fallback we use the optimizer; if it can't 686 * prove the condition is false, it will cause a link error on the undefined 687 * "__build_bug_on_failed". This error message can be harder to track down 688 * though, hence the two different methods. 689 */ 690 #ifndef __OPTIMIZE__ 691 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)])) 692 #else 693 extern int __build_bug_on_failed; 694 #define BUILD_BUG_ON(condition) \ 695 do { \ 696 ((void)sizeof(char[1 - 2*!!(condition)])); \ 697 if (condition) __build_bug_on_failed = 1; \ 698 } while(0) 699 #endif 700 #endif /* __CHECKER__ */ 701 702 /* Trap pasters of __FUNCTION__ at compile-time */ 703 #define __FUNCTION__ (__func__) 704 705 /* This helps us to avoid #ifdef CONFIG_NUMA */ 706 #ifdef CONFIG_NUMA 707 #define NUMA_BUILD 1 708 #else 709 #define NUMA_BUILD 0 710 #endif 711 712 /* This helps us avoid #ifdef CONFIG_COMPACTION */ 713 #ifdef CONFIG_COMPACTION 714 #define COMPACTION_BUILD 1 715 #else 716 #define COMPACTION_BUILD 0 717 #endif 718 719 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ 720 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 721 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD 722 #endif 723 724 struct sysinfo; 725 extern int do_sysinfo(struct sysinfo *info); 726 727 #endif /* __KERNEL__ */ 728 729 #define SI_LOAD_SHIFT 16 730 struct sysinfo { 731 long uptime; /* Seconds since boot */ 732 unsigned long loads[3]; /* 1, 5, and 15 minute load averages */ 733 unsigned long totalram; /* Total usable main memory size */ 734 unsigned long freeram; /* Available memory size */ 735 unsigned long sharedram; /* Amount of shared memory */ 736 unsigned long bufferram; /* Memory used by buffers */ 737 unsigned long totalswap; /* Total swap space size */ 738 unsigned long freeswap; /* swap space still available */ 739 unsigned short procs; /* Number of current processes */ 740 unsigned short pad; /* explicit padding for m68k */ 741 unsigned long totalhigh; /* Total high memory size */ 742 unsigned long freehigh; /* Available high memory size */ 743 unsigned int mem_unit; /* Memory unit size in bytes */ 744 char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */ 745 }; 746 747 #endif 748