kernel.h 21 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. #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_debug.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. void log_buf_kexec_setup(void);
  226. #else
  227. static inline int vprintk(const char *s, va_list args)
  228. __attribute__ ((format (printf, 1, 0)));
  229. static inline int vprintk(const char *s, va_list args) { return 0; }
  230. static inline int printk(const char *s, ...)
  231. __attribute__ ((format (printf, 1, 2)));
  232. static inline int __cold printk(const char *s, ...) { return 0; }
  233. static inline int printk_ratelimit(void) { return 0; }
  234. static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
  235. unsigned int interval_msec) \
  236. { return false; }
  237. /* No effect, but we still get type checking even in the !PRINTK case: */
  238. #define printk_once(x...) printk(x)
  239. static inline void log_buf_kexec_setup(void)
  240. {
  241. }
  242. #endif
  243. extern int printk_needs_cpu(int cpu);
  244. extern void printk_tick(void);
  245. extern void asmlinkage __attribute__((format(printf, 1, 2)))
  246. early_printk(const char *fmt, ...);
  247. unsigned long int_sqrt(unsigned long);
  248. static inline void console_silent(void)
  249. {
  250. console_loglevel = 0;
  251. }
  252. static inline void console_verbose(void)
  253. {
  254. if (console_loglevel)
  255. console_loglevel = 15;
  256. }
  257. extern void bust_spinlocks(int yes);
  258. extern void wake_up_klogd(void);
  259. extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
  260. extern int panic_timeout;
  261. extern int panic_on_oops;
  262. extern int panic_on_unrecovered_nmi;
  263. extern const char *print_tainted(void);
  264. extern void add_taint(unsigned flag);
  265. extern int test_taint(unsigned flag);
  266. extern unsigned long get_taint(void);
  267. extern int root_mountflags;
  268. /* Values used for system_state */
  269. extern enum system_states {
  270. SYSTEM_BOOTING,
  271. SYSTEM_RUNNING,
  272. SYSTEM_HALT,
  273. SYSTEM_POWER_OFF,
  274. SYSTEM_RESTART,
  275. SYSTEM_SUSPEND_DISK,
  276. } system_state;
  277. #define TAINT_PROPRIETARY_MODULE 0
  278. #define TAINT_FORCED_MODULE 1
  279. #define TAINT_UNSAFE_SMP 2
  280. #define TAINT_FORCED_RMMOD 3
  281. #define TAINT_MACHINE_CHECK 4
  282. #define TAINT_BAD_PAGE 5
  283. #define TAINT_USER 6
  284. #define TAINT_DIE 7
  285. #define TAINT_OVERRIDDEN_ACPI_TABLE 8
  286. #define TAINT_WARN 9
  287. #define TAINT_CRAP 10
  288. extern void dump_stack(void) __cold;
  289. enum {
  290. DUMP_PREFIX_NONE,
  291. DUMP_PREFIX_ADDRESS,
  292. DUMP_PREFIX_OFFSET
  293. };
  294. extern void hex_dump_to_buffer(const void *buf, size_t len,
  295. int rowsize, int groupsize,
  296. char *linebuf, size_t linebuflen, bool ascii);
  297. extern void print_hex_dump(const char *level, const char *prefix_str,
  298. int prefix_type, int rowsize, int groupsize,
  299. const void *buf, size_t len, bool ascii);
  300. extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
  301. const void *buf, size_t len);
  302. extern const char hex_asc[];
  303. #define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
  304. #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
  305. static inline char *pack_hex_byte(char *buf, u8 byte)
  306. {
  307. *buf++ = hex_asc_hi(byte);
  308. *buf++ = hex_asc_lo(byte);
  309. return buf;
  310. }
  311. #ifndef pr_fmt
  312. #define pr_fmt(fmt) fmt
  313. #endif
  314. #define pr_emerg(fmt, ...) \
  315. printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
  316. #define pr_alert(fmt, ...) \
  317. printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
  318. #define pr_crit(fmt, ...) \
  319. printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
  320. #define pr_err(fmt, ...) \
  321. printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
  322. #define pr_warning(fmt, ...) \
  323. printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
  324. #define pr_notice(fmt, ...) \
  325. printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
  326. #define pr_info(fmt, ...) \
  327. printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
  328. #define pr_cont(fmt, ...) \
  329. printk(KERN_CONT fmt, ##__VA_ARGS__)
  330. /* If you are writing a driver, please use dev_dbg instead */
  331. #if defined(DEBUG)
  332. #define pr_debug(fmt, ...) \
  333. printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
  334. #elif defined(CONFIG_DYNAMIC_DEBUG)
  335. /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
  336. #define pr_debug(fmt, ...) do { \
  337. dynamic_pr_debug(fmt, ##__VA_ARGS__); \
  338. } while (0)
  339. #else
  340. #define pr_debug(fmt, ...) \
  341. ({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
  342. #endif
  343. /*
  344. * General tracing related utility functions - trace_printk(),
  345. * tracing_on/tracing_off and tracing_start()/tracing_stop
  346. *
  347. * Use tracing_on/tracing_off when you want to quickly turn on or off
  348. * tracing. It simply enables or disables the recording of the trace events.
  349. * This also corresponds to the user space debugfs/tracing/tracing_on
  350. * file, which gives a means for the kernel and userspace to interact.
  351. * Place a tracing_off() in the kernel where you want tracing to end.
  352. * From user space, examine the trace, and then echo 1 > tracing_on
  353. * to continue tracing.
  354. *
  355. * tracing_stop/tracing_start has slightly more overhead. It is used
  356. * by things like suspend to ram where disabling the recording of the
  357. * trace is not enough, but tracing must actually stop because things
  358. * like calling smp_processor_id() may crash the system.
  359. *
  360. * Most likely, you want to use tracing_on/tracing_off.
  361. */
  362. #ifdef CONFIG_RING_BUFFER
  363. void tracing_on(void);
  364. void tracing_off(void);
  365. /* trace_off_permanent stops recording with no way to bring it back */
  366. void tracing_off_permanent(void);
  367. int tracing_is_on(void);
  368. #else
  369. static inline void tracing_on(void) { }
  370. static inline void tracing_off(void) { }
  371. static inline void tracing_off_permanent(void) { }
  372. static inline int tracing_is_on(void) { return 0; }
  373. #endif
  374. #ifdef CONFIG_TRACING
  375. extern void tracing_start(void);
  376. extern void tracing_stop(void);
  377. extern void ftrace_off_permanent(void);
  378. extern void
  379. ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
  380. static inline void __attribute__ ((format (printf, 1, 2)))
  381. ____trace_printk_check_format(const char *fmt, ...)
  382. {
  383. }
  384. #define __trace_printk_check_format(fmt, args...) \
  385. do { \
  386. if (0) \
  387. ____trace_printk_check_format(fmt, ##args); \
  388. } while (0)
  389. /**
  390. * trace_printk - printf formatting in the ftrace buffer
  391. * @fmt: the printf format for printing
  392. *
  393. * Note: __trace_printk is an internal function for trace_printk and
  394. * the @ip is passed in via the trace_printk macro.
  395. *
  396. * This function allows a kernel developer to debug fast path sections
  397. * that printk is not appropriate for. By scattering in various
  398. * printk like tracing in the code, a developer can quickly see
  399. * where problems are occurring.
  400. *
  401. * This is intended as a debugging tool for the developer only.
  402. * Please refrain from leaving trace_printks scattered around in
  403. * your code.
  404. */
  405. #define trace_printk(fmt, args...) \
  406. do { \
  407. __trace_printk_check_format(fmt, ##args); \
  408. if (__builtin_constant_p(fmt)) { \
  409. static const char *trace_printk_fmt \
  410. __attribute__((section("__trace_printk_fmt"))) = \
  411. __builtin_constant_p(fmt) ? fmt : NULL; \
  412. \
  413. __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
  414. } else \
  415. __trace_printk(_THIS_IP_, fmt, ##args); \
  416. } while (0)
  417. extern int
  418. __trace_bprintk(unsigned long ip, const char *fmt, ...)
  419. __attribute__ ((format (printf, 2, 3)));
  420. extern int
  421. __trace_printk(unsigned long ip, const char *fmt, ...)
  422. __attribute__ ((format (printf, 2, 3)));
  423. /*
  424. * The double __builtin_constant_p is because gcc will give us an error
  425. * if we try to allocate the static variable to fmt if it is not a
  426. * constant. Even with the outer if statement.
  427. */
  428. #define ftrace_vprintk(fmt, vargs) \
  429. do { \
  430. if (__builtin_constant_p(fmt)) { \
  431. static const char *trace_printk_fmt \
  432. __attribute__((section("__trace_printk_fmt"))) = \
  433. __builtin_constant_p(fmt) ? fmt : NULL; \
  434. \
  435. __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
  436. } else \
  437. __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
  438. } while (0)
  439. extern int
  440. __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
  441. extern int
  442. __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
  443. extern void ftrace_dump(void);
  444. #else
  445. static inline void
  446. ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
  447. static inline int
  448. trace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
  449. static inline void tracing_start(void) { }
  450. static inline void tracing_stop(void) { }
  451. static inline void ftrace_off_permanent(void) { }
  452. static inline int
  453. trace_printk(const char *fmt, ...)
  454. {
  455. return 0;
  456. }
  457. static inline int
  458. ftrace_vprintk(const char *fmt, va_list ap)
  459. {
  460. return 0;
  461. }
  462. static inline void ftrace_dump(void) { }
  463. #endif /* CONFIG_TRACING */
  464. /*
  465. * Display an IP address in readable format.
  466. */
  467. #define NIPQUAD(addr) \
  468. ((unsigned char *)&addr)[0], \
  469. ((unsigned char *)&addr)[1], \
  470. ((unsigned char *)&addr)[2], \
  471. ((unsigned char *)&addr)[3]
  472. #define NIPQUAD_FMT "%u.%u.%u.%u"
  473. /*
  474. * min()/max()/clamp() macros that also do
  475. * strict type-checking.. See the
  476. * "unnecessary" pointer comparison.
  477. */
  478. #define min(x, y) ({ \
  479. typeof(x) _min1 = (x); \
  480. typeof(y) _min2 = (y); \
  481. (void) (&_min1 == &_min2); \
  482. _min1 < _min2 ? _min1 : _min2; })
  483. #define max(x, y) ({ \
  484. typeof(x) _max1 = (x); \
  485. typeof(y) _max2 = (y); \
  486. (void) (&_max1 == &_max2); \
  487. _max1 > _max2 ? _max1 : _max2; })
  488. /**
  489. * clamp - return a value clamped to a given range with strict typechecking
  490. * @val: current value
  491. * @min: minimum allowable value
  492. * @max: maximum allowable value
  493. *
  494. * This macro does strict typechecking of min/max to make sure they are of the
  495. * same type as val. See the unnecessary pointer comparisons.
  496. */
  497. #define clamp(val, min, max) ({ \
  498. typeof(val) __val = (val); \
  499. typeof(min) __min = (min); \
  500. typeof(max) __max = (max); \
  501. (void) (&__val == &__min); \
  502. (void) (&__val == &__max); \
  503. __val = __val < __min ? __min: __val; \
  504. __val > __max ? __max: __val; })
  505. /*
  506. * ..and if you can't take the strict
  507. * types, you can specify one yourself.
  508. *
  509. * Or not use min/max/clamp at all, of course.
  510. */
  511. #define min_t(type, x, y) ({ \
  512. type __min1 = (x); \
  513. type __min2 = (y); \
  514. __min1 < __min2 ? __min1: __min2; })
  515. #define max_t(type, x, y) ({ \
  516. type __max1 = (x); \
  517. type __max2 = (y); \
  518. __max1 > __max2 ? __max1: __max2; })
  519. /**
  520. * clamp_t - return a value clamped to a given range using a given type
  521. * @type: the type of variable to use
  522. * @val: current value
  523. * @min: minimum allowable value
  524. * @max: maximum allowable value
  525. *
  526. * This macro does no typechecking and uses temporary variables of type
  527. * 'type' to make all the comparisons.
  528. */
  529. #define clamp_t(type, val, min, max) ({ \
  530. type __val = (val); \
  531. type __min = (min); \
  532. type __max = (max); \
  533. __val = __val < __min ? __min: __val; \
  534. __val > __max ? __max: __val; })
  535. /**
  536. * clamp_val - return a value clamped to a given range using val's type
  537. * @val: current value
  538. * @min: minimum allowable value
  539. * @max: maximum allowable value
  540. *
  541. * This macro does no typechecking and uses temporary variables of whatever
  542. * type the input argument 'val' is. This is useful when val is an unsigned
  543. * type and min and max are literals that will otherwise be assigned a signed
  544. * integer type.
  545. */
  546. #define clamp_val(val, min, max) ({ \
  547. typeof(val) __val = (val); \
  548. typeof(val) __min = (min); \
  549. typeof(val) __max = (max); \
  550. __val = __val < __min ? __min: __val; \
  551. __val > __max ? __max: __val; })
  552. /*
  553. * swap - swap value of @a and @b
  554. */
  555. #define swap(a, b) \
  556. do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
  557. /**
  558. * container_of - cast a member of a structure out to the containing structure
  559. * @ptr: the pointer to the member.
  560. * @type: the type of the container struct this is embedded in.
  561. * @member: the name of the member within the struct.
  562. *
  563. */
  564. #define container_of(ptr, type, member) ({ \
  565. const typeof( ((type *)0)->member ) *__mptr = (ptr); \
  566. (type *)( (char *)__mptr - offsetof(type,member) );})
  567. struct sysinfo;
  568. extern int do_sysinfo(struct sysinfo *info);
  569. #endif /* __KERNEL__ */
  570. #define SI_LOAD_SHIFT 16
  571. struct sysinfo {
  572. long uptime; /* Seconds since boot */
  573. unsigned long loads[3]; /* 1, 5, and 15 minute load averages */
  574. unsigned long totalram; /* Total usable main memory size */
  575. unsigned long freeram; /* Available memory size */
  576. unsigned long sharedram; /* Amount of shared memory */
  577. unsigned long bufferram; /* Memory used by buffers */
  578. unsigned long totalswap; /* Total swap space size */
  579. unsigned long freeswap; /* swap space still available */
  580. unsigned short procs; /* Number of current processes */
  581. unsigned short pad; /* explicit padding for m68k */
  582. unsigned long totalhigh; /* Total high memory size */
  583. unsigned long freehigh; /* Available high memory size */
  584. unsigned int mem_unit; /* Memory unit size in bytes */
  585. char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
  586. };
  587. /* Force a compilation error if condition is true */
  588. #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
  589. /* Force a compilation error if condition is true, but also produce a
  590. result (of value 0 and type size_t), so the expression can be used
  591. e.g. in a structure initializer (or where-ever else comma expressions
  592. aren't permitted). */
  593. #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
  594. /* Trap pasters of __FUNCTION__ at compile-time */
  595. #define __FUNCTION__ (__func__)
  596. /* This helps us to avoid #ifdef CONFIG_NUMA */
  597. #ifdef CONFIG_NUMA
  598. #define NUMA_BUILD 1
  599. #else
  600. #define NUMA_BUILD 0
  601. #endif
  602. /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
  603. #ifdef CONFIG_FTRACE_MCOUNT_RECORD
  604. # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
  605. #endif
  606. #endif