kernel.h 23 KB

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