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