kernel.h 22 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_LBDAF
  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. /* Use the default kernel loglevel */
  86. #define KERN_DEFAULT "<d>"
  87. /*
  88. * Annotation for a "continued" line of log printout (only done after a
  89. * line that had no enclosing \n). Only to be used by core/arch code
  90. * during early bootup (a continued line is not SMP-safe otherwise).
  91. */
  92. #define KERN_CONT "<c>"
  93. extern int console_printk[];
  94. #define console_loglevel (console_printk[0])
  95. #define default_message_loglevel (console_printk[1])
  96. #define minimum_console_loglevel (console_printk[2])
  97. #define default_console_loglevel (console_printk[3])
  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(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(char *file, int line, int preempt_offset) { }
  123. # define might_sleep() do { might_resched(); } while (0)
  124. #endif
  125. #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
  126. #define abs(x) ({ \
  127. int __x = (x); \
  128. (__x < 0) ? -__x : __x; \
  129. })
  130. #ifdef CONFIG_PROVE_LOCKING
  131. void might_fault(void);
  132. #else
  133. static inline void might_fault(void)
  134. {
  135. might_sleep();
  136. }
  137. #endif
  138. extern struct atomic_notifier_head panic_notifier_list;
  139. extern long (*panic_blink)(long time);
  140. NORET_TYPE void panic(const char * fmt, ...)
  141. __attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
  142. extern void oops_enter(void);
  143. extern void oops_exit(void);
  144. extern int oops_may_print(void);
  145. NORET_TYPE void do_exit(long error_code)
  146. ATTRIB_NORET;
  147. NORET_TYPE void complete_and_exit(struct completion *, long)
  148. ATTRIB_NORET;
  149. extern unsigned long simple_strtoul(const char *,char **,unsigned int);
  150. extern long simple_strtol(const char *,char **,unsigned int);
  151. extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
  152. extern long long simple_strtoll(const char *,char **,unsigned int);
  153. extern int strict_strtoul(const char *, unsigned int, unsigned long *);
  154. extern int strict_strtol(const char *, unsigned int, long *);
  155. extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
  156. extern int strict_strtoll(const char *, unsigned int, long long *);
  157. extern int sprintf(char * buf, const char * fmt, ...)
  158. __attribute__ ((format (printf, 2, 3)));
  159. extern int vsprintf(char *buf, const char *, va_list)
  160. __attribute__ ((format (printf, 2, 0)));
  161. extern int snprintf(char * buf, size_t size, const char * fmt, ...)
  162. __attribute__ ((format (printf, 3, 4)));
  163. extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
  164. __attribute__ ((format (printf, 3, 0)));
  165. extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
  166. __attribute__ ((format (printf, 3, 4)));
  167. extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
  168. __attribute__ ((format (printf, 3, 0)));
  169. extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
  170. __attribute__ ((format (printf, 2, 3)));
  171. extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
  172. extern int sscanf(const char *, const char *, ...)
  173. __attribute__ ((format (scanf, 2, 3)));
  174. extern int vsscanf(const char *, const char *, va_list)
  175. __attribute__ ((format (scanf, 2, 0)));
  176. extern int get_option(char **str, int *pint);
  177. extern char *get_options(const char *str, int nints, int *ints);
  178. extern unsigned long long memparse(const char *ptr, char **retptr);
  179. extern int core_kernel_text(unsigned long addr);
  180. extern int __kernel_text_address(unsigned long addr);
  181. extern int kernel_text_address(unsigned long addr);
  182. extern int func_ptr_is_kernel_text(void *ptr);
  183. struct pid;
  184. extern struct pid *session_of_pgrp(struct pid *pgrp);
  185. /*
  186. * FW_BUG
  187. * Add this to a message where you are sure the firmware is buggy or behaves
  188. * really stupid or out of spec. Be aware that the responsible BIOS developer
  189. * should be able to fix this issue or at least get a concrete idea of the
  190. * problem by reading your message without the need of looking at the kernel
  191. * code.
  192. *
  193. * Use it for definite and high priority BIOS bugs.
  194. *
  195. * FW_WARN
  196. * Use it for not that clear (e.g. could the kernel messed up things already?)
  197. * and medium priority BIOS bugs.
  198. *
  199. * FW_INFO
  200. * Use this one if you want to tell the user or vendor about something
  201. * suspicious, but generally harmless related to the firmware.
  202. *
  203. * Use it for information or very low priority BIOS bugs.
  204. */
  205. #define FW_BUG "[Firmware Bug]: "
  206. #define FW_WARN "[Firmware Warn]: "
  207. #define FW_INFO "[Firmware Info]: "
  208. #ifdef CONFIG_PRINTK
  209. asmlinkage int vprintk(const char *fmt, va_list args)
  210. __attribute__ ((format (printf, 1, 0)));
  211. asmlinkage int printk(const char * fmt, ...)
  212. __attribute__ ((format (printf, 1, 2))) __cold;
  213. extern struct ratelimit_state printk_ratelimit_state;
  214. extern int printk_ratelimit(void);
  215. extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
  216. unsigned int interval_msec);
  217. extern int printk_delay_msec;
  218. /*
  219. * Print a one-time message (analogous to WARN_ONCE() et al):
  220. */
  221. #define printk_once(x...) ({ \
  222. static int __print_once = 1; \
  223. \
  224. if (__print_once) { \
  225. __print_once = 0; \
  226. printk(x); \
  227. } \
  228. })
  229. void log_buf_kexec_setup(void);
  230. #else
  231. static inline int vprintk(const char *s, va_list args)
  232. __attribute__ ((format (printf, 1, 0)));
  233. static inline int vprintk(const char *s, va_list args) { return 0; }
  234. static inline int printk(const char *s, ...)
  235. __attribute__ ((format (printf, 1, 2)));
  236. static inline int __cold printk(const char *s, ...) { return 0; }
  237. static inline int printk_ratelimit(void) { return 0; }
  238. static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
  239. unsigned int interval_msec) \
  240. { return false; }
  241. /* No effect, but we still get type checking even in the !PRINTK case: */
  242. #define printk_once(x...) printk(x)
  243. static inline void log_buf_kexec_setup(void)
  244. {
  245. }
  246. #endif
  247. extern int printk_needs_cpu(int cpu);
  248. extern void printk_tick(void);
  249. extern void asmlinkage __attribute__((format(printf, 1, 2)))
  250. early_printk(const char *fmt, ...);
  251. unsigned long int_sqrt(unsigned long);
  252. static inline void console_silent(void)
  253. {
  254. console_loglevel = 0;
  255. }
  256. static inline void console_verbose(void)
  257. {
  258. if (console_loglevel)
  259. console_loglevel = 15;
  260. }
  261. extern void bust_spinlocks(int yes);
  262. extern void wake_up_klogd(void);
  263. extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
  264. extern int panic_timeout;
  265. extern int panic_on_oops;
  266. extern int panic_on_unrecovered_nmi;
  267. extern int panic_on_io_nmi;
  268. extern const char *print_tainted(void);
  269. extern void add_taint(unsigned flag);
  270. extern int test_taint(unsigned flag);
  271. extern unsigned long get_taint(void);
  272. extern int root_mountflags;
  273. /* Values used for system_state */
  274. extern enum system_states {
  275. SYSTEM_BOOTING,
  276. SYSTEM_RUNNING,
  277. SYSTEM_HALT,
  278. SYSTEM_POWER_OFF,
  279. SYSTEM_RESTART,
  280. SYSTEM_SUSPEND_DISK,
  281. } system_state;
  282. #define TAINT_PROPRIETARY_MODULE 0
  283. #define TAINT_FORCED_MODULE 1
  284. #define TAINT_UNSAFE_SMP 2
  285. #define TAINT_FORCED_RMMOD 3
  286. #define TAINT_MACHINE_CHECK 4
  287. #define TAINT_BAD_PAGE 5
  288. #define TAINT_USER 6
  289. #define TAINT_DIE 7
  290. #define TAINT_OVERRIDDEN_ACPI_TABLE 8
  291. #define TAINT_WARN 9
  292. #define TAINT_CRAP 10
  293. extern void dump_stack(void) __cold;
  294. enum {
  295. DUMP_PREFIX_NONE,
  296. DUMP_PREFIX_ADDRESS,
  297. DUMP_PREFIX_OFFSET
  298. };
  299. extern void hex_dump_to_buffer(const void *buf, size_t len,
  300. int rowsize, int groupsize,
  301. char *linebuf, size_t linebuflen, bool ascii);
  302. extern void print_hex_dump(const char *level, const char *prefix_str,
  303. int prefix_type, int rowsize, int groupsize,
  304. const void *buf, size_t len, bool ascii);
  305. extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
  306. const void *buf, size_t len);
  307. extern const char hex_asc[];
  308. #define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
  309. #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
  310. static inline char *pack_hex_byte(char *buf, u8 byte)
  311. {
  312. *buf++ = hex_asc_hi(byte);
  313. *buf++ = hex_asc_lo(byte);
  314. return buf;
  315. }
  316. #ifndef pr_fmt
  317. #define pr_fmt(fmt) fmt
  318. #endif
  319. #define pr_emerg(fmt, ...) \
  320. printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
  321. #define pr_alert(fmt, ...) \
  322. printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
  323. #define pr_crit(fmt, ...) \
  324. printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
  325. #define pr_err(fmt, ...) \
  326. printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
  327. #define pr_warning(fmt, ...) \
  328. printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
  329. #define pr_notice(fmt, ...) \
  330. printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
  331. #define pr_info(fmt, ...) \
  332. printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
  333. #define pr_cont(fmt, ...) \
  334. printk(KERN_CONT fmt, ##__VA_ARGS__)
  335. /* pr_devel() should produce zero code unless DEBUG is defined */
  336. #ifdef DEBUG
  337. #define pr_devel(fmt, ...) \
  338. printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
  339. #else
  340. #define pr_devel(fmt, ...) \
  341. ({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
  342. #endif
  343. /* If you are writing a driver, please use dev_dbg instead */
  344. #if defined(DEBUG)
  345. #define pr_debug(fmt, ...) \
  346. printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
  347. #elif defined(CONFIG_DYNAMIC_DEBUG)
  348. /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
  349. #define pr_debug(fmt, ...) do { \
  350. dynamic_pr_debug(fmt, ##__VA_ARGS__); \
  351. } while (0)
  352. #else
  353. #define pr_debug(fmt, ...) \
  354. ({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
  355. #endif
  356. /*
  357. * General tracing related utility functions - trace_printk(),
  358. * tracing_on/tracing_off and tracing_start()/tracing_stop
  359. *
  360. * Use tracing_on/tracing_off when you want to quickly turn on or off
  361. * tracing. It simply enables or disables the recording of the trace events.
  362. * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
  363. * file, which gives a means for the kernel and userspace to interact.
  364. * Place a tracing_off() in the kernel where you want tracing to end.
  365. * From user space, examine the trace, and then echo 1 > tracing_on
  366. * to continue tracing.
  367. *
  368. * tracing_stop/tracing_start has slightly more overhead. It is used
  369. * by things like suspend to ram where disabling the recording of the
  370. * trace is not enough, but tracing must actually stop because things
  371. * like calling smp_processor_id() may crash the system.
  372. *
  373. * Most likely, you want to use tracing_on/tracing_off.
  374. */
  375. #ifdef CONFIG_RING_BUFFER
  376. void tracing_on(void);
  377. void tracing_off(void);
  378. /* trace_off_permanent stops recording with no way to bring it back */
  379. void tracing_off_permanent(void);
  380. int tracing_is_on(void);
  381. #else
  382. static inline void tracing_on(void) { }
  383. static inline void tracing_off(void) { }
  384. static inline void tracing_off_permanent(void) { }
  385. static inline int tracing_is_on(void) { return 0; }
  386. #endif
  387. #ifdef CONFIG_TRACING
  388. extern void tracing_start(void);
  389. extern void tracing_stop(void);
  390. extern void ftrace_off_permanent(void);
  391. extern void
  392. ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
  393. static inline void __attribute__ ((format (printf, 1, 2)))
  394. ____trace_printk_check_format(const char *fmt, ...)
  395. {
  396. }
  397. #define __trace_printk_check_format(fmt, args...) \
  398. do { \
  399. if (0) \
  400. ____trace_printk_check_format(fmt, ##args); \
  401. } while (0)
  402. /**
  403. * trace_printk - printf formatting in the ftrace buffer
  404. * @fmt: the printf format for printing
  405. *
  406. * Note: __trace_printk is an internal function for trace_printk and
  407. * the @ip is passed in via the trace_printk macro.
  408. *
  409. * This function allows a kernel developer to debug fast path sections
  410. * that printk is not appropriate for. By scattering in various
  411. * printk like tracing in the code, a developer can quickly see
  412. * where problems are occurring.
  413. *
  414. * This is intended as a debugging tool for the developer only.
  415. * Please refrain from leaving trace_printks scattered around in
  416. * your code.
  417. */
  418. #define trace_printk(fmt, args...) \
  419. do { \
  420. __trace_printk_check_format(fmt, ##args); \
  421. if (__builtin_constant_p(fmt)) { \
  422. static const char *trace_printk_fmt \
  423. __attribute__((section("__trace_printk_fmt"))) = \
  424. __builtin_constant_p(fmt) ? fmt : NULL; \
  425. \
  426. __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
  427. } else \
  428. __trace_printk(_THIS_IP_, fmt, ##args); \
  429. } while (0)
  430. extern int
  431. __trace_bprintk(unsigned long ip, const char *fmt, ...)
  432. __attribute__ ((format (printf, 2, 3)));
  433. extern int
  434. __trace_printk(unsigned long ip, const char *fmt, ...)
  435. __attribute__ ((format (printf, 2, 3)));
  436. /*
  437. * The double __builtin_constant_p is because gcc will give us an error
  438. * if we try to allocate the static variable to fmt if it is not a
  439. * constant. Even with the outer if statement.
  440. */
  441. #define ftrace_vprintk(fmt, vargs) \
  442. do { \
  443. if (__builtin_constant_p(fmt)) { \
  444. static const char *trace_printk_fmt \
  445. __attribute__((section("__trace_printk_fmt"))) = \
  446. __builtin_constant_p(fmt) ? fmt : NULL; \
  447. \
  448. __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
  449. } else \
  450. __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
  451. } while (0)
  452. extern int
  453. __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
  454. extern int
  455. __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
  456. extern void ftrace_dump(void);
  457. #else
  458. static inline void
  459. ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
  460. static inline int
  461. trace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
  462. static inline void tracing_start(void) { }
  463. static inline void tracing_stop(void) { }
  464. static inline void ftrace_off_permanent(void) { }
  465. static inline int
  466. trace_printk(const char *fmt, ...)
  467. {
  468. return 0;
  469. }
  470. static inline int
  471. ftrace_vprintk(const char *fmt, va_list ap)
  472. {
  473. return 0;
  474. }
  475. static inline void ftrace_dump(void) { }
  476. #endif /* CONFIG_TRACING */
  477. /*
  478. * Display an IP address in readable format.
  479. */
  480. #define NIPQUAD(addr) \
  481. ((unsigned char *)&addr)[0], \
  482. ((unsigned char *)&addr)[1], \
  483. ((unsigned char *)&addr)[2], \
  484. ((unsigned char *)&addr)[3]
  485. #define NIPQUAD_FMT "%u.%u.%u.%u"
  486. /*
  487. * min()/max()/clamp() macros that also do
  488. * strict type-checking.. See the
  489. * "unnecessary" pointer comparison.
  490. */
  491. #define min(x, y) ({ \
  492. typeof(x) _min1 = (x); \
  493. typeof(y) _min2 = (y); \
  494. (void) (&_min1 == &_min2); \
  495. _min1 < _min2 ? _min1 : _min2; })
  496. #define max(x, y) ({ \
  497. typeof(x) _max1 = (x); \
  498. typeof(y) _max2 = (y); \
  499. (void) (&_max1 == &_max2); \
  500. _max1 > _max2 ? _max1 : _max2; })
  501. /**
  502. * clamp - return a value clamped to a given range with strict typechecking
  503. * @val: current value
  504. * @min: minimum allowable value
  505. * @max: maximum allowable value
  506. *
  507. * This macro does strict typechecking of min/max to make sure they are of the
  508. * same type as val. See the unnecessary pointer comparisons.
  509. */
  510. #define clamp(val, min, max) ({ \
  511. typeof(val) __val = (val); \
  512. typeof(min) __min = (min); \
  513. typeof(max) __max = (max); \
  514. (void) (&__val == &__min); \
  515. (void) (&__val == &__max); \
  516. __val = __val < __min ? __min: __val; \
  517. __val > __max ? __max: __val; })
  518. /*
  519. * ..and if you can't take the strict
  520. * types, you can specify one yourself.
  521. *
  522. * Or not use min/max/clamp at all, of course.
  523. */
  524. #define min_t(type, x, y) ({ \
  525. type __min1 = (x); \
  526. type __min2 = (y); \
  527. __min1 < __min2 ? __min1: __min2; })
  528. #define max_t(type, x, y) ({ \
  529. type __max1 = (x); \
  530. type __max2 = (y); \
  531. __max1 > __max2 ? __max1: __max2; })
  532. /**
  533. * clamp_t - return a value clamped to a given range using a given type
  534. * @type: the type of variable to use
  535. * @val: current value
  536. * @min: minimum allowable value
  537. * @max: maximum allowable value
  538. *
  539. * This macro does no typechecking and uses temporary variables of type
  540. * 'type' to make all the comparisons.
  541. */
  542. #define clamp_t(type, val, min, max) ({ \
  543. type __val = (val); \
  544. type __min = (min); \
  545. type __max = (max); \
  546. __val = __val < __min ? __min: __val; \
  547. __val > __max ? __max: __val; })
  548. /**
  549. * clamp_val - return a value clamped to a given range using val's type
  550. * @val: current value
  551. * @min: minimum allowable value
  552. * @max: maximum allowable value
  553. *
  554. * This macro does no typechecking and uses temporary variables of whatever
  555. * type the input argument 'val' is. This is useful when val is an unsigned
  556. * type and min and max are literals that will otherwise be assigned a signed
  557. * integer type.
  558. */
  559. #define clamp_val(val, min, max) ({ \
  560. typeof(val) __val = (val); \
  561. typeof(val) __min = (min); \
  562. typeof(val) __max = (max); \
  563. __val = __val < __min ? __min: __val; \
  564. __val > __max ? __max: __val; })
  565. /*
  566. * swap - swap value of @a and @b
  567. */
  568. #define swap(a, b) \
  569. do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
  570. /**
  571. * container_of - cast a member of a structure out to the containing structure
  572. * @ptr: the pointer to the member.
  573. * @type: the type of the container struct this is embedded in.
  574. * @member: the name of the member within the struct.
  575. *
  576. */
  577. #define container_of(ptr, type, member) ({ \
  578. const typeof( ((type *)0)->member ) *__mptr = (ptr); \
  579. (type *)( (char *)__mptr - offsetof(type,member) );})
  580. struct sysinfo;
  581. extern int do_sysinfo(struct sysinfo *info);
  582. #endif /* __KERNEL__ */
  583. #define SI_LOAD_SHIFT 16
  584. struct sysinfo {
  585. long uptime; /* Seconds since boot */
  586. unsigned long loads[3]; /* 1, 5, and 15 minute load averages */
  587. unsigned long totalram; /* Total usable main memory size */
  588. unsigned long freeram; /* Available memory size */
  589. unsigned long sharedram; /* Amount of shared memory */
  590. unsigned long bufferram; /* Memory used by buffers */
  591. unsigned long totalswap; /* Total swap space size */
  592. unsigned long freeswap; /* swap space still available */
  593. unsigned short procs; /* Number of current processes */
  594. unsigned short pad; /* explicit padding for m68k */
  595. unsigned long totalhigh; /* Total high memory size */
  596. unsigned long freehigh; /* Available high memory size */
  597. unsigned int mem_unit; /* Memory unit size in bytes */
  598. char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
  599. };
  600. /* Force a compilation error if condition is true */
  601. #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
  602. /* Force a compilation error if condition is true, but also produce a
  603. result (of value 0 and type size_t), so the expression can be used
  604. e.g. in a structure initializer (or where-ever else comma expressions
  605. aren't permitted). */
  606. #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
  607. /* Trap pasters of __FUNCTION__ at compile-time */
  608. #define __FUNCTION__ (__func__)
  609. /* This helps us to avoid #ifdef CONFIG_NUMA */
  610. #ifdef CONFIG_NUMA
  611. #define NUMA_BUILD 1
  612. #else
  613. #define NUMA_BUILD 0
  614. #endif
  615. /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
  616. #ifdef CONFIG_FTRACE_MCOUNT_RECORD
  617. # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
  618. #endif
  619. #endif