kernel.h 21 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680
  1. #ifndef _LINUX_KERNEL_H
  2. #define _LINUX_KERNEL_H
  3. /*
  4. * 'kernel.h' contains some often-used function prototypes etc
  5. */
  6. #ifdef __KERNEL__
  7. #include <stdarg.h>
  8. #include <linux/linkage.h>
  9. #include <linux/stddef.h>
  10. #include <linux/types.h>
  11. #include <linux/compiler.h>
  12. #include <linux/bitops.h>
  13. #include <linux/log2.h>
  14. #include <linux/typecheck.h>
  15. #include <linux/ratelimit.h>
  16. #include <linux/dynamic_printk.h>
  17. #include <asm/byteorder.h>
  18. #include <asm/bug.h>
  19. extern const char linux_banner[];
  20. extern const char linux_proc_banner[];
  21. #define USHORT_MAX ((u16)(~0U))
  22. #define SHORT_MAX ((s16)(USHORT_MAX>>1))
  23. #define SHORT_MIN (-SHORT_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_MASK(x,(typeof(x))(a)-1)
  35. #define __ALIGN_MASK(x,mask) (((x)+(mask))&~(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. #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
  40. #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
  41. #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
  42. #define DIV_ROUND_CLOSEST(x, divisor)( \
  43. { \
  44. typeof(divisor) __divisor = divisor; \
  45. (((x) + ((__divisor) / 2)) / (__divisor)); \
  46. } \
  47. )
  48. #define _RET_IP_ (unsigned long)__builtin_return_address(0)
  49. #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
  50. #ifdef CONFIG_LBD
  51. # include <asm/div64.h>
  52. # define sector_div(a, b) do_div(a, b)
  53. #else
  54. # define sector_div(n, b)( \
  55. { \
  56. int _res; \
  57. _res = (n) % (b); \
  58. (n) /= (b); \
  59. _res; \
  60. } \
  61. )
  62. #endif
  63. /**
  64. * upper_32_bits - return bits 32-63 of a number
  65. * @n: the number we're accessing
  66. *
  67. * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
  68. * the "right shift count >= width of type" warning when that quantity is
  69. * 32-bits.
  70. */
  71. #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
  72. /**
  73. * lower_32_bits - return bits 0-31 of a number
  74. * @n: the number we're accessing
  75. */
  76. #define lower_32_bits(n) ((u32)(n))
  77. #define KERN_EMERG "<0>" /* system is unusable */
  78. #define KERN_ALERT "<1>" /* action must be taken immediately */
  79. #define KERN_CRIT "<2>" /* critical conditions */
  80. #define KERN_ERR "<3>" /* error conditions */
  81. #define KERN_WARNING "<4>" /* warning conditions */
  82. #define KERN_NOTICE "<5>" /* normal but significant condition */
  83. #define KERN_INFO "<6>" /* informational */
  84. #define KERN_DEBUG "<7>" /* debug-level messages */
  85. /*
  86. * Annotation for a "continued" line of log printout (only done after a
  87. * line that had no enclosing \n). Only to be used by core/arch code
  88. * during early bootup (a continued line is not SMP-safe otherwise).
  89. */
  90. #define KERN_CONT ""
  91. extern int console_printk[];
  92. #define console_loglevel (console_printk[0])
  93. #define default_message_loglevel (console_printk[1])
  94. #define minimum_console_loglevel (console_printk[2])
  95. #define default_console_loglevel (console_printk[3])
  96. struct completion;
  97. struct pt_regs;
  98. struct user;
  99. #ifdef CONFIG_PREEMPT_VOLUNTARY
  100. extern int _cond_resched(void);
  101. # define might_resched() _cond_resched()
  102. #else
  103. # define might_resched() do { } while (0)
  104. #endif
  105. #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
  106. void __might_sleep(char *file, int line);
  107. /**
  108. * might_sleep - annotation for functions that can sleep
  109. *
  110. * this macro will print a stack trace if it is executed in an atomic
  111. * context (spinlock, irq-handler, ...).
  112. *
  113. * This is a useful debugging help to be able to catch problems early and not
  114. * be bitten later when the calling function happens to sleep when it is not
  115. * supposed to.
  116. */
  117. # define might_sleep() \
  118. do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
  119. #else
  120. # define might_sleep() do { might_resched(); } while (0)
  121. #endif
  122. #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
  123. #define abs(x) ({ \
  124. int __x = (x); \
  125. (__x < 0) ? -__x : __x; \
  126. })
  127. #ifdef CONFIG_PROVE_LOCKING
  128. void might_fault(void);
  129. #else
  130. static inline void might_fault(void)
  131. {
  132. might_sleep();
  133. }
  134. #endif
  135. extern struct atomic_notifier_head panic_notifier_list;
  136. extern long (*panic_blink)(long time);
  137. NORET_TYPE void panic(const char * fmt, ...)
  138. __attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
  139. extern void oops_enter(void);
  140. extern void oops_exit(void);
  141. extern int oops_may_print(void);
  142. NORET_TYPE void do_exit(long error_code)
  143. ATTRIB_NORET;
  144. NORET_TYPE void complete_and_exit(struct completion *, long)
  145. ATTRIB_NORET;
  146. extern unsigned long simple_strtoul(const char *,char **,unsigned int);
  147. extern long simple_strtol(const char *,char **,unsigned int);
  148. extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
  149. extern long long simple_strtoll(const char *,char **,unsigned int);
  150. extern int strict_strtoul(const char *, unsigned int, unsigned long *);
  151. extern int strict_strtol(const char *, unsigned int, long *);
  152. extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
  153. extern int strict_strtoll(const char *, unsigned int, long long *);
  154. extern int sprintf(char * buf, const char * fmt, ...)
  155. __attribute__ ((format (printf, 2, 3)));
  156. extern int vsprintf(char *buf, const char *, va_list)
  157. __attribute__ ((format (printf, 2, 0)));
  158. extern int snprintf(char * buf, size_t size, const char * fmt, ...)
  159. __attribute__ ((format (printf, 3, 4)));
  160. extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
  161. __attribute__ ((format (printf, 3, 0)));
  162. extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
  163. __attribute__ ((format (printf, 3, 4)));
  164. extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
  165. __attribute__ ((format (printf, 3, 0)));
  166. extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
  167. __attribute__ ((format (printf, 2, 3)));
  168. extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
  169. extern int sscanf(const char *, const char *, ...)
  170. __attribute__ ((format (scanf, 2, 3)));
  171. extern int vsscanf(const char *, const char *, va_list)
  172. __attribute__ ((format (scanf, 2, 0)));
  173. extern int get_option(char **str, int *pint);
  174. extern char *get_options(const char *str, int nints, int *ints);
  175. extern unsigned long long memparse(const char *ptr, char **retptr);
  176. extern int core_kernel_text(unsigned long addr);
  177. extern int __kernel_text_address(unsigned long addr);
  178. extern int kernel_text_address(unsigned long addr);
  179. extern int func_ptr_is_kernel_text(void *ptr);
  180. struct pid;
  181. extern struct pid *session_of_pgrp(struct pid *pgrp);
  182. /*
  183. * FW_BUG
  184. * Add this to a message where you are sure the firmware is buggy or behaves
  185. * really stupid or out of spec. Be aware that the responsible BIOS developer
  186. * should be able to fix this issue or at least get a concrete idea of the
  187. * problem by reading your message without the need of looking at the kernel
  188. * code.
  189. *
  190. * Use it for definite and high priority BIOS bugs.
  191. *
  192. * FW_WARN
  193. * Use it for not that clear (e.g. could the kernel messed up things already?)
  194. * and medium priority BIOS bugs.
  195. *
  196. * FW_INFO
  197. * Use this one if you want to tell the user or vendor about something
  198. * suspicious, but generally harmless related to the firmware.
  199. *
  200. * Use it for information or very low priority BIOS bugs.
  201. */
  202. #define FW_BUG "[Firmware Bug]: "
  203. #define FW_WARN "[Firmware Warn]: "
  204. #define FW_INFO "[Firmware Info]: "
  205. #ifdef CONFIG_PRINTK
  206. asmlinkage int vprintk(const char *fmt, va_list args)
  207. __attribute__ ((format (printf, 1, 0)));
  208. asmlinkage int printk(const char * fmt, ...)
  209. __attribute__ ((format (printf, 1, 2))) __cold;
  210. extern struct ratelimit_state printk_ratelimit_state;
  211. extern int printk_ratelimit(void);
  212. extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
  213. unsigned int interval_msec);
  214. /*
  215. * Print a one-time message (analogous to WARN_ONCE() et al):
  216. */
  217. #define printk_once(x...) ({ \
  218. static int __print_once = 1; \
  219. \
  220. if (__print_once) { \
  221. __print_once = 0; \
  222. printk(x); \
  223. } \
  224. })
  225. #else
  226. static inline int vprintk(const char *s, va_list args)
  227. __attribute__ ((format (printf, 1, 0)));
  228. static inline int vprintk(const char *s, va_list args) { return 0; }
  229. static inline int printk(const char *s, ...)
  230. __attribute__ ((format (printf, 1, 2)));
  231. static inline int __cold printk(const char *s, ...) { return 0; }
  232. static inline int printk_ratelimit(void) { return 0; }
  233. static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
  234. unsigned int interval_msec) \
  235. { return false; }
  236. /* No effect, but we still get type checking even in the !PRINTK case: */
  237. #define printk_once(x...) printk(x)
  238. #endif
  239. extern int printk_needs_cpu(int cpu);
  240. extern void printk_tick(void);
  241. extern void asmlinkage __attribute__((format(printf, 1, 2)))
  242. early_printk(const char *fmt, ...);
  243. unsigned long int_sqrt(unsigned long);
  244. static inline void console_silent(void)
  245. {
  246. console_loglevel = 0;
  247. }
  248. static inline void console_verbose(void)
  249. {
  250. if (console_loglevel)
  251. console_loglevel = 15;
  252. }
  253. extern void bust_spinlocks(int yes);
  254. extern void wake_up_klogd(void);
  255. extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
  256. extern int panic_timeout;
  257. extern int panic_on_oops;
  258. extern int panic_on_unrecovered_nmi;
  259. extern const char *print_tainted(void);
  260. extern void add_taint(unsigned flag);
  261. extern int test_taint(unsigned flag);
  262. extern unsigned long get_taint(void);
  263. extern int root_mountflags;
  264. /* Values used for system_state */
  265. extern enum system_states {
  266. SYSTEM_BOOTING,
  267. SYSTEM_RUNNING,
  268. SYSTEM_HALT,
  269. SYSTEM_POWER_OFF,
  270. SYSTEM_RESTART,
  271. SYSTEM_SUSPEND_DISK,
  272. } system_state;
  273. #define TAINT_PROPRIETARY_MODULE 0
  274. #define TAINT_FORCED_MODULE 1
  275. #define TAINT_UNSAFE_SMP 2
  276. #define TAINT_FORCED_RMMOD 3
  277. #define TAINT_MACHINE_CHECK 4
  278. #define TAINT_BAD_PAGE 5
  279. #define TAINT_USER 6
  280. #define TAINT_DIE 7
  281. #define TAINT_OVERRIDDEN_ACPI_TABLE 8
  282. #define TAINT_WARN 9
  283. #define TAINT_CRAP 10
  284. extern void dump_stack(void) __cold;
  285. enum {
  286. DUMP_PREFIX_NONE,
  287. DUMP_PREFIX_ADDRESS,
  288. DUMP_PREFIX_OFFSET
  289. };
  290. extern void hex_dump_to_buffer(const void *buf, size_t len,
  291. int rowsize, int groupsize,
  292. char *linebuf, size_t linebuflen, bool ascii);
  293. extern void print_hex_dump(const char *level, const char *prefix_str,
  294. int prefix_type, int rowsize, int groupsize,
  295. const void *buf, size_t len, bool ascii);
  296. extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
  297. const void *buf, size_t len);
  298. extern const char hex_asc[];
  299. #define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
  300. #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
  301. static inline char *pack_hex_byte(char *buf, u8 byte)
  302. {
  303. *buf++ = hex_asc_hi(byte);
  304. *buf++ = hex_asc_lo(byte);
  305. return buf;
  306. }
  307. #ifndef pr_fmt
  308. #define pr_fmt(fmt) fmt
  309. #endif
  310. #define pr_emerg(fmt, ...) \
  311. printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
  312. #define pr_alert(fmt, ...) \
  313. printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
  314. #define pr_crit(fmt, ...) \
  315. printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
  316. #define pr_err(fmt, ...) \
  317. printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
  318. #define pr_warning(fmt, ...) \
  319. printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
  320. #define pr_notice(fmt, ...) \
  321. printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
  322. #define pr_info(fmt, ...) \
  323. printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
  324. /* If you are writing a driver, please use dev_dbg instead */
  325. #if defined(DEBUG)
  326. #define pr_debug(fmt, ...) \
  327. printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
  328. #elif defined(CONFIG_DYNAMIC_PRINTK_DEBUG)
  329. #define pr_debug(fmt, ...) do { \
  330. dynamic_pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
  331. } while (0)
  332. #else
  333. #define pr_debug(fmt, ...) \
  334. ({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
  335. #endif
  336. /*
  337. * General tracing related utility functions - trace_printk(),
  338. * tracing_on/tracing_off and tracing_start()/tracing_stop
  339. *
  340. * Use tracing_on/tracing_off when you want to quickly turn on or off
  341. * tracing. It simply enables or disables the recording of the trace events.
  342. * This also corresponds to the user space debugfs/tracing/tracing_on
  343. * file, which gives a means for the kernel and userspace to interact.
  344. * Place a tracing_off() in the kernel where you want tracing to end.
  345. * From user space, examine the trace, and then echo 1 > tracing_on
  346. * to continue tracing.
  347. *
  348. * tracing_stop/tracing_start has slightly more overhead. It is used
  349. * by things like suspend to ram where disabling the recording of the
  350. * trace is not enough, but tracing must actually stop because things
  351. * like calling smp_processor_id() may crash the system.
  352. *
  353. * Most likely, you want to use tracing_on/tracing_off.
  354. */
  355. #ifdef CONFIG_RING_BUFFER
  356. void tracing_on(void);
  357. void tracing_off(void);
  358. /* trace_off_permanent stops recording with no way to bring it back */
  359. void tracing_off_permanent(void);
  360. int tracing_is_on(void);
  361. #else
  362. static inline void tracing_on(void) { }
  363. static inline void tracing_off(void) { }
  364. static inline void tracing_off_permanent(void) { }
  365. static inline int tracing_is_on(void) { return 0; }
  366. #endif
  367. #ifdef CONFIG_TRACING
  368. extern void tracing_start(void);
  369. extern void tracing_stop(void);
  370. extern void ftrace_off_permanent(void);
  371. extern void
  372. ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
  373. static inline void __attribute__ ((format (printf, 1, 2)))
  374. ____trace_printk_check_format(const char *fmt, ...)
  375. {
  376. }
  377. #define __trace_printk_check_format(fmt, args...) \
  378. do { \
  379. if (0) \
  380. ____trace_printk_check_format(fmt, ##args); \
  381. } while (0)
  382. /**
  383. * trace_printk - printf formatting in the ftrace buffer
  384. * @fmt: the printf format for printing
  385. *
  386. * Note: __trace_printk is an internal function for trace_printk and
  387. * the @ip is passed in via the trace_printk macro.
  388. *
  389. * This function allows a kernel developer to debug fast path sections
  390. * that printk is not appropriate for. By scattering in various
  391. * printk like tracing in the code, a developer can quickly see
  392. * where problems are occurring.
  393. *
  394. * This is intended as a debugging tool for the developer only.
  395. * Please refrain from leaving trace_printks scattered around in
  396. * your code.
  397. */
  398. #define trace_printk(fmt, args...) \
  399. do { \
  400. static const char *trace_printk_fmt \
  401. __attribute__((section("__trace_printk_fmt"))); \
  402. \
  403. if (!trace_printk_fmt) \
  404. trace_printk_fmt = fmt; \
  405. \
  406. __trace_printk_check_format(fmt, ##args); \
  407. __trace_printk(_THIS_IP_, trace_printk_fmt, ##args); \
  408. } while (0)
  409. extern int
  410. __trace_printk(unsigned long ip, const char *fmt, ...)
  411. __attribute__ ((format (printf, 2, 3)));
  412. #define ftrace_vprintk(fmt, vargs) \
  413. do { \
  414. static const char *trace_printk_fmt \
  415. __attribute__((section("__trace_printk_fmt"))); \
  416. \
  417. if (!trace_printk_fmt) \
  418. trace_printk_fmt = fmt; \
  419. \
  420. __ftrace_vprintk(_THIS_IP_, trace_printk_fmt, vargs); \
  421. } while (0)
  422. extern int
  423. __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
  424. extern void ftrace_dump(void);
  425. #else
  426. static inline void
  427. ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
  428. static inline int
  429. trace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
  430. static inline void tracing_start(void) { }
  431. static inline void tracing_stop(void) { }
  432. static inline void ftrace_off_permanent(void) { }
  433. static inline int
  434. trace_printk(const char *fmt, ...)
  435. {
  436. return 0;
  437. }
  438. static inline int
  439. ftrace_vprintk(const char *fmt, va_list ap)
  440. {
  441. return 0;
  442. }
  443. static inline void ftrace_dump(void) { }
  444. #endif /* CONFIG_TRACING */
  445. /*
  446. * Display an IP address in readable format.
  447. */
  448. #define NIPQUAD(addr) \
  449. ((unsigned char *)&addr)[0], \
  450. ((unsigned char *)&addr)[1], \
  451. ((unsigned char *)&addr)[2], \
  452. ((unsigned char *)&addr)[3]
  453. #define NIPQUAD_FMT "%u.%u.%u.%u"
  454. #if defined(__LITTLE_ENDIAN)
  455. #define HIPQUAD(addr) \
  456. ((unsigned char *)&addr)[3], \
  457. ((unsigned char *)&addr)[2], \
  458. ((unsigned char *)&addr)[1], \
  459. ((unsigned char *)&addr)[0]
  460. #elif defined(__BIG_ENDIAN)
  461. #define HIPQUAD NIPQUAD
  462. #else
  463. #error "Please fix asm/byteorder.h"
  464. #endif /* __LITTLE_ENDIAN */
  465. /*
  466. * min()/max()/clamp() macros that also do
  467. * strict type-checking.. See the
  468. * "unnecessary" pointer comparison.
  469. */
  470. #define min(x, y) ({ \
  471. typeof(x) _min1 = (x); \
  472. typeof(y) _min2 = (y); \
  473. (void) (&_min1 == &_min2); \
  474. _min1 < _min2 ? _min1 : _min2; })
  475. #define max(x, y) ({ \
  476. typeof(x) _max1 = (x); \
  477. typeof(y) _max2 = (y); \
  478. (void) (&_max1 == &_max2); \
  479. _max1 > _max2 ? _max1 : _max2; })
  480. /**
  481. * clamp - return a value clamped to a given range with strict typechecking
  482. * @val: current value
  483. * @min: minimum allowable value
  484. * @max: maximum allowable value
  485. *
  486. * This macro does strict typechecking of min/max to make sure they are of the
  487. * same type as val. See the unnecessary pointer comparisons.
  488. */
  489. #define clamp(val, min, max) ({ \
  490. typeof(val) __val = (val); \
  491. typeof(min) __min = (min); \
  492. typeof(max) __max = (max); \
  493. (void) (&__val == &__min); \
  494. (void) (&__val == &__max); \
  495. __val = __val < __min ? __min: __val; \
  496. __val > __max ? __max: __val; })
  497. /*
  498. * ..and if you can't take the strict
  499. * types, you can specify one yourself.
  500. *
  501. * Or not use min/max/clamp at all, of course.
  502. */
  503. #define min_t(type, x, y) ({ \
  504. type __min1 = (x); \
  505. type __min2 = (y); \
  506. __min1 < __min2 ? __min1: __min2; })
  507. #define max_t(type, x, y) ({ \
  508. type __max1 = (x); \
  509. type __max2 = (y); \
  510. __max1 > __max2 ? __max1: __max2; })
  511. /**
  512. * clamp_t - return a value clamped to a given range using a given type
  513. * @type: the type of variable to use
  514. * @val: current value
  515. * @min: minimum allowable value
  516. * @max: maximum allowable value
  517. *
  518. * This macro does no typechecking and uses temporary variables of type
  519. * 'type' to make all the comparisons.
  520. */
  521. #define clamp_t(type, val, min, max) ({ \
  522. type __val = (val); \
  523. type __min = (min); \
  524. type __max = (max); \
  525. __val = __val < __min ? __min: __val; \
  526. __val > __max ? __max: __val; })
  527. /**
  528. * clamp_val - return a value clamped to a given range using val's type
  529. * @val: current value
  530. * @min: minimum allowable value
  531. * @max: maximum allowable value
  532. *
  533. * This macro does no typechecking and uses temporary variables of whatever
  534. * type the input argument 'val' is. This is useful when val is an unsigned
  535. * type and min and max are literals that will otherwise be assigned a signed
  536. * integer type.
  537. */
  538. #define clamp_val(val, min, max) ({ \
  539. typeof(val) __val = (val); \
  540. typeof(val) __min = (min); \
  541. typeof(val) __max = (max); \
  542. __val = __val < __min ? __min: __val; \
  543. __val > __max ? __max: __val; })
  544. /*
  545. * swap - swap value of @a and @b
  546. */
  547. #define swap(a, b) \
  548. do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
  549. /**
  550. * container_of - cast a member of a structure out to the containing structure
  551. * @ptr: the pointer to the member.
  552. * @type: the type of the container struct this is embedded in.
  553. * @member: the name of the member within the struct.
  554. *
  555. */
  556. #define container_of(ptr, type, member) ({ \
  557. const typeof( ((type *)0)->member ) *__mptr = (ptr); \
  558. (type *)( (char *)__mptr - offsetof(type,member) );})
  559. struct sysinfo;
  560. extern int do_sysinfo(struct sysinfo *info);
  561. #endif /* __KERNEL__ */
  562. #define SI_LOAD_SHIFT 16
  563. struct sysinfo {
  564. long uptime; /* Seconds since boot */
  565. unsigned long loads[3]; /* 1, 5, and 15 minute load averages */
  566. unsigned long totalram; /* Total usable main memory size */
  567. unsigned long freeram; /* Available memory size */
  568. unsigned long sharedram; /* Amount of shared memory */
  569. unsigned long bufferram; /* Memory used by buffers */
  570. unsigned long totalswap; /* Total swap space size */
  571. unsigned long freeswap; /* swap space still available */
  572. unsigned short procs; /* Number of current processes */
  573. unsigned short pad; /* explicit padding for m68k */
  574. unsigned long totalhigh; /* Total high memory size */
  575. unsigned long freehigh; /* Available high memory size */
  576. unsigned int mem_unit; /* Memory unit size in bytes */
  577. char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
  578. };
  579. /* Force a compilation error if condition is true */
  580. #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
  581. /* Force a compilation error if condition is true, but also produce a
  582. result (of value 0 and type size_t), so the expression can be used
  583. e.g. in a structure initializer (or where-ever else comma expressions
  584. aren't permitted). */
  585. #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
  586. /* Trap pasters of __FUNCTION__ at compile-time */
  587. #define __FUNCTION__ (__func__)
  588. /* This helps us to avoid #ifdef CONFIG_NUMA */
  589. #ifdef CONFIG_NUMA
  590. #define NUMA_BUILD 1
  591. #else
  592. #define NUMA_BUILD 0
  593. #endif
  594. /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
  595. #ifdef CONFIG_FTRACE_MCOUNT_RECORD
  596. # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
  597. #endif
  598. #endif