kernel.h 21 KB

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  1. #ifndef _LINUX_KERNEL_H
  2. #define _LINUX_KERNEL_H
  3. #include <linux/sysinfo.h>
  4. /*
  5. * 'kernel.h' contains some often-used function prototypes etc
  6. */
  7. #define __ALIGN_KERNEL(x, a) __ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
  8. #define __ALIGN_KERNEL_MASK(x, mask) (((x) + (mask)) & ~(mask))
  9. #ifdef __KERNEL__
  10. #include <stdarg.h>
  11. #include <linux/linkage.h>
  12. #include <linux/stddef.h>
  13. #include <linux/types.h>
  14. #include <linux/compiler.h>
  15. #include <linux/bitops.h>
  16. #include <linux/log2.h>
  17. #include <linux/typecheck.h>
  18. #include <linux/printk.h>
  19. #include <linux/dynamic_debug.h>
  20. #include <asm/byteorder.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. /*
  77. * Multiplies an integer by a fraction, while avoiding unnecessary
  78. * overflow or loss of precision.
  79. */
  80. #define mult_frac(x, numer, denom)( \
  81. { \
  82. typeof(x) quot = (x) / (denom); \
  83. typeof(x) rem = (x) % (denom); \
  84. (quot * (numer)) + ((rem * (numer)) / (denom)); \
  85. } \
  86. )
  87. #define _RET_IP_ (unsigned long)__builtin_return_address(0)
  88. #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
  89. #ifdef CONFIG_LBDAF
  90. # include <asm/div64.h>
  91. # define sector_div(a, b) do_div(a, b)
  92. #else
  93. # define sector_div(n, b)( \
  94. { \
  95. int _res; \
  96. _res = (n) % (b); \
  97. (n) /= (b); \
  98. _res; \
  99. } \
  100. )
  101. #endif
  102. /**
  103. * upper_32_bits - return bits 32-63 of a number
  104. * @n: the number we're accessing
  105. *
  106. * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
  107. * the "right shift count >= width of type" warning when that quantity is
  108. * 32-bits.
  109. */
  110. #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
  111. /**
  112. * lower_32_bits - return bits 0-31 of a number
  113. * @n: the number we're accessing
  114. */
  115. #define lower_32_bits(n) ((u32)(n))
  116. struct completion;
  117. struct pt_regs;
  118. struct user;
  119. #ifdef CONFIG_PREEMPT_VOLUNTARY
  120. extern int _cond_resched(void);
  121. # define might_resched() _cond_resched()
  122. #else
  123. # define might_resched() do { } while (0)
  124. #endif
  125. #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
  126. void __might_sleep(const char *file, int line, int preempt_offset);
  127. /**
  128. * might_sleep - annotation for functions that can sleep
  129. *
  130. * this macro will print a stack trace if it is executed in an atomic
  131. * context (spinlock, irq-handler, ...).
  132. *
  133. * This is a useful debugging help to be able to catch problems early and not
  134. * be bitten later when the calling function happens to sleep when it is not
  135. * supposed to.
  136. */
  137. # define might_sleep() \
  138. do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
  139. #else
  140. static inline void __might_sleep(const char *file, int line,
  141. int preempt_offset) { }
  142. # define might_sleep() do { might_resched(); } while (0)
  143. #endif
  144. #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
  145. /*
  146. * abs() handles unsigned and signed longs, ints, shorts and chars. For all
  147. * input types abs() returns a signed long.
  148. * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64()
  149. * for those.
  150. */
  151. #define abs(x) ({ \
  152. long ret; \
  153. if (sizeof(x) == sizeof(long)) { \
  154. long __x = (x); \
  155. ret = (__x < 0) ? -__x : __x; \
  156. } else { \
  157. int __x = (x); \
  158. ret = (__x < 0) ? -__x : __x; \
  159. } \
  160. ret; \
  161. })
  162. #define abs64(x) ({ \
  163. s64 __x = (x); \
  164. (__x < 0) ? -__x : __x; \
  165. })
  166. #ifdef CONFIG_PROVE_LOCKING
  167. void might_fault(void);
  168. #else
  169. static inline void might_fault(void)
  170. {
  171. might_sleep();
  172. }
  173. #endif
  174. extern struct atomic_notifier_head panic_notifier_list;
  175. extern long (*panic_blink)(int state);
  176. __printf(1, 2)
  177. void panic(const char *fmt, ...)
  178. __noreturn __cold;
  179. extern void oops_enter(void);
  180. extern void oops_exit(void);
  181. void print_oops_end_marker(void);
  182. extern int oops_may_print(void);
  183. void do_exit(long error_code)
  184. __noreturn;
  185. void complete_and_exit(struct completion *, long)
  186. __noreturn;
  187. /* Internal, do not use. */
  188. int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
  189. int __must_check _kstrtol(const char *s, unsigned int base, long *res);
  190. int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
  191. int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
  192. static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
  193. {
  194. /*
  195. * We want to shortcut function call, but
  196. * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
  197. */
  198. if (sizeof(unsigned long) == sizeof(unsigned long long) &&
  199. __alignof__(unsigned long) == __alignof__(unsigned long long))
  200. return kstrtoull(s, base, (unsigned long long *)res);
  201. else
  202. return _kstrtoul(s, base, res);
  203. }
  204. static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
  205. {
  206. /*
  207. * We want to shortcut function call, but
  208. * __builtin_types_compatible_p(long, long long) = 0.
  209. */
  210. if (sizeof(long) == sizeof(long long) &&
  211. __alignof__(long) == __alignof__(long long))
  212. return kstrtoll(s, base, (long long *)res);
  213. else
  214. return _kstrtol(s, base, res);
  215. }
  216. int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
  217. int __must_check kstrtoint(const char *s, unsigned int base, int *res);
  218. static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
  219. {
  220. return kstrtoull(s, base, res);
  221. }
  222. static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
  223. {
  224. return kstrtoll(s, base, res);
  225. }
  226. static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
  227. {
  228. return kstrtouint(s, base, res);
  229. }
  230. static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
  231. {
  232. return kstrtoint(s, base, res);
  233. }
  234. int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
  235. int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
  236. int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
  237. int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
  238. int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
  239. int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
  240. int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
  241. int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
  242. int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
  243. int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
  244. int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
  245. int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
  246. int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
  247. int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
  248. static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
  249. {
  250. return kstrtoull_from_user(s, count, base, res);
  251. }
  252. static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
  253. {
  254. return kstrtoll_from_user(s, count, base, res);
  255. }
  256. static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
  257. {
  258. return kstrtouint_from_user(s, count, base, res);
  259. }
  260. static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
  261. {
  262. return kstrtoint_from_user(s, count, base, res);
  263. }
  264. /* Obsolete, do not use. Use kstrto<foo> instead */
  265. extern unsigned long simple_strtoul(const char *,char **,unsigned int);
  266. extern long simple_strtol(const char *,char **,unsigned int);
  267. extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
  268. extern long long simple_strtoll(const char *,char **,unsigned int);
  269. #define strict_strtoul kstrtoul
  270. #define strict_strtol kstrtol
  271. #define strict_strtoull kstrtoull
  272. #define strict_strtoll kstrtoll
  273. extern int num_to_str(char *buf, int size, unsigned long long num);
  274. /* lib/printf utilities */
  275. extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
  276. extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
  277. extern __printf(3, 4)
  278. int snprintf(char *buf, size_t size, const char *fmt, ...);
  279. extern __printf(3, 0)
  280. int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
  281. extern __printf(3, 4)
  282. int scnprintf(char *buf, size_t size, const char *fmt, ...);
  283. extern __printf(3, 0)
  284. int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
  285. extern __printf(2, 3)
  286. char *kasprintf(gfp_t gfp, const char *fmt, ...);
  287. extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
  288. extern __scanf(2, 3)
  289. int sscanf(const char *, const char *, ...);
  290. extern __scanf(2, 0)
  291. int vsscanf(const char *, const char *, va_list);
  292. extern int get_option(char **str, int *pint);
  293. extern char *get_options(const char *str, int nints, int *ints);
  294. extern unsigned long long memparse(const char *ptr, char **retptr);
  295. extern int core_kernel_text(unsigned long addr);
  296. extern int core_kernel_data(unsigned long addr);
  297. extern int __kernel_text_address(unsigned long addr);
  298. extern int kernel_text_address(unsigned long addr);
  299. extern int func_ptr_is_kernel_text(void *ptr);
  300. struct pid;
  301. extern struct pid *session_of_pgrp(struct pid *pgrp);
  302. unsigned long int_sqrt(unsigned long);
  303. extern void bust_spinlocks(int yes);
  304. extern void wake_up_klogd(void);
  305. extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
  306. extern int panic_timeout;
  307. extern int panic_on_oops;
  308. extern int panic_on_unrecovered_nmi;
  309. extern int panic_on_io_nmi;
  310. extern int sysctl_panic_on_stackoverflow;
  311. extern const char *print_tainted(void);
  312. extern void add_taint(unsigned flag);
  313. extern int test_taint(unsigned flag);
  314. extern unsigned long get_taint(void);
  315. extern int root_mountflags;
  316. extern bool early_boot_irqs_disabled;
  317. /* Values used for system_state */
  318. extern enum system_states {
  319. SYSTEM_BOOTING,
  320. SYSTEM_RUNNING,
  321. SYSTEM_HALT,
  322. SYSTEM_POWER_OFF,
  323. SYSTEM_RESTART,
  324. SYSTEM_SUSPEND_DISK,
  325. } system_state;
  326. #define TAINT_PROPRIETARY_MODULE 0
  327. #define TAINT_FORCED_MODULE 1
  328. #define TAINT_UNSAFE_SMP 2
  329. #define TAINT_FORCED_RMMOD 3
  330. #define TAINT_MACHINE_CHECK 4
  331. #define TAINT_BAD_PAGE 5
  332. #define TAINT_USER 6
  333. #define TAINT_DIE 7
  334. #define TAINT_OVERRIDDEN_ACPI_TABLE 8
  335. #define TAINT_WARN 9
  336. #define TAINT_CRAP 10
  337. #define TAINT_FIRMWARE_WORKAROUND 11
  338. #define TAINT_OOT_MODULE 12
  339. extern const char hex_asc[];
  340. #define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
  341. #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
  342. static inline char *hex_byte_pack(char *buf, u8 byte)
  343. {
  344. *buf++ = hex_asc_hi(byte);
  345. *buf++ = hex_asc_lo(byte);
  346. return buf;
  347. }
  348. static inline char * __deprecated pack_hex_byte(char *buf, u8 byte)
  349. {
  350. return hex_byte_pack(buf, byte);
  351. }
  352. extern int hex_to_bin(char ch);
  353. extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
  354. /*
  355. * General tracing related utility functions - trace_printk(),
  356. * tracing_on/tracing_off and tracing_start()/tracing_stop
  357. *
  358. * Use tracing_on/tracing_off when you want to quickly turn on or off
  359. * tracing. It simply enables or disables the recording of the trace events.
  360. * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
  361. * file, which gives a means for the kernel and userspace to interact.
  362. * Place a tracing_off() in the kernel where you want tracing to end.
  363. * From user space, examine the trace, and then echo 1 > tracing_on
  364. * to continue tracing.
  365. *
  366. * tracing_stop/tracing_start has slightly more overhead. It is used
  367. * by things like suspend to ram where disabling the recording of the
  368. * trace is not enough, but tracing must actually stop because things
  369. * like calling smp_processor_id() may crash the system.
  370. *
  371. * Most likely, you want to use tracing_on/tracing_off.
  372. */
  373. #ifdef CONFIG_RING_BUFFER
  374. /* trace_off_permanent stops recording with no way to bring it back */
  375. void tracing_off_permanent(void);
  376. #else
  377. static inline void tracing_off_permanent(void) { }
  378. #endif
  379. enum ftrace_dump_mode {
  380. DUMP_NONE,
  381. DUMP_ALL,
  382. DUMP_ORIG,
  383. };
  384. #ifdef CONFIG_TRACING
  385. void tracing_on(void);
  386. void tracing_off(void);
  387. int tracing_is_on(void);
  388. extern void tracing_start(void);
  389. extern void tracing_stop(void);
  390. extern void ftrace_off_permanent(void);
  391. static inline __printf(1, 2)
  392. void ____trace_printk_check_format(const char *fmt, ...)
  393. {
  394. }
  395. #define __trace_printk_check_format(fmt, args...) \
  396. do { \
  397. if (0) \
  398. ____trace_printk_check_format(fmt, ##args); \
  399. } while (0)
  400. /**
  401. * trace_printk - printf formatting in the ftrace buffer
  402. * @fmt: the printf format for printing
  403. *
  404. * Note: __trace_printk is an internal function for trace_printk and
  405. * the @ip is passed in via the trace_printk macro.
  406. *
  407. * This function allows a kernel developer to debug fast path sections
  408. * that printk is not appropriate for. By scattering in various
  409. * printk like tracing in the code, a developer can quickly see
  410. * where problems are occurring.
  411. *
  412. * This is intended as a debugging tool for the developer only.
  413. * Please refrain from leaving trace_printks scattered around in
  414. * your code.
  415. */
  416. #define trace_printk(fmt, args...) \
  417. do { \
  418. static const char *trace_printk_fmt \
  419. __attribute__((section("__trace_printk_fmt"))) = \
  420. __builtin_constant_p(fmt) ? fmt : NULL; \
  421. \
  422. __trace_printk_check_format(fmt, ##args); \
  423. \
  424. if (__builtin_constant_p(fmt)) \
  425. __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
  426. else \
  427. __trace_printk(_THIS_IP_, fmt, ##args); \
  428. } while (0)
  429. extern __printf(2, 3)
  430. int __trace_bprintk(unsigned long ip, const char *fmt, ...);
  431. extern __printf(2, 3)
  432. int __trace_printk(unsigned long ip, const char *fmt, ...);
  433. extern void trace_dump_stack(void);
  434. /*
  435. * The double __builtin_constant_p is because gcc will give us an error
  436. * if we try to allocate the static variable to fmt if it is not a
  437. * constant. Even with the outer if statement.
  438. */
  439. #define ftrace_vprintk(fmt, vargs) \
  440. do { \
  441. if (__builtin_constant_p(fmt)) { \
  442. static const char *trace_printk_fmt \
  443. __attribute__((section("__trace_printk_fmt"))) = \
  444. __builtin_constant_p(fmt) ? fmt : NULL; \
  445. \
  446. __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
  447. } else \
  448. __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
  449. } while (0)
  450. extern int
  451. __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
  452. extern int
  453. __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
  454. extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
  455. #else
  456. static inline __printf(1, 2)
  457. int trace_printk(const char *fmt, ...);
  458. static inline void tracing_start(void) { }
  459. static inline void tracing_stop(void) { }
  460. static inline void ftrace_off_permanent(void) { }
  461. static inline void trace_dump_stack(void) { }
  462. static inline void tracing_on(void) { }
  463. static inline void tracing_off(void) { }
  464. static inline int tracing_is_on(void) { return 0; }
  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(enum ftrace_dump_mode oops_dump_mode) { }
  476. #endif /* CONFIG_TRACING */
  477. /*
  478. * min()/max()/clamp() macros that also do
  479. * strict type-checking.. See the
  480. * "unnecessary" pointer comparison.
  481. */
  482. #define min(x, y) ({ \
  483. typeof(x) _min1 = (x); \
  484. typeof(y) _min2 = (y); \
  485. (void) (&_min1 == &_min2); \
  486. _min1 < _min2 ? _min1 : _min2; })
  487. #define max(x, y) ({ \
  488. typeof(x) _max1 = (x); \
  489. typeof(y) _max2 = (y); \
  490. (void) (&_max1 == &_max2); \
  491. _max1 > _max2 ? _max1 : _max2; })
  492. #define min3(x, y, z) ({ \
  493. typeof(x) _min1 = (x); \
  494. typeof(y) _min2 = (y); \
  495. typeof(z) _min3 = (z); \
  496. (void) (&_min1 == &_min2); \
  497. (void) (&_min1 == &_min3); \
  498. _min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \
  499. (_min2 < _min3 ? _min2 : _min3); })
  500. #define max3(x, y, z) ({ \
  501. typeof(x) _max1 = (x); \
  502. typeof(y) _max2 = (y); \
  503. typeof(z) _max3 = (z); \
  504. (void) (&_max1 == &_max2); \
  505. (void) (&_max1 == &_max3); \
  506. _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \
  507. (_max2 > _max3 ? _max2 : _max3); })
  508. /**
  509. * min_not_zero - return the minimum that is _not_ zero, unless both are zero
  510. * @x: value1
  511. * @y: value2
  512. */
  513. #define min_not_zero(x, y) ({ \
  514. typeof(x) __x = (x); \
  515. typeof(y) __y = (y); \
  516. __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
  517. /**
  518. * clamp - return a value clamped to a given range with strict typechecking
  519. * @val: current value
  520. * @min: minimum allowable value
  521. * @max: maximum allowable value
  522. *
  523. * This macro does strict typechecking of min/max to make sure they are of the
  524. * same type as val. See the unnecessary pointer comparisons.
  525. */
  526. #define clamp(val, min, max) ({ \
  527. typeof(val) __val = (val); \
  528. typeof(min) __min = (min); \
  529. typeof(max) __max = (max); \
  530. (void) (&__val == &__min); \
  531. (void) (&__val == &__max); \
  532. __val = __val < __min ? __min: __val; \
  533. __val > __max ? __max: __val; })
  534. /*
  535. * ..and if you can't take the strict
  536. * types, you can specify one yourself.
  537. *
  538. * Or not use min/max/clamp at all, of course.
  539. */
  540. #define min_t(type, x, y) ({ \
  541. type __min1 = (x); \
  542. type __min2 = (y); \
  543. __min1 < __min2 ? __min1: __min2; })
  544. #define max_t(type, x, y) ({ \
  545. type __max1 = (x); \
  546. type __max2 = (y); \
  547. __max1 > __max2 ? __max1: __max2; })
  548. /**
  549. * clamp_t - return a value clamped to a given range using a given type
  550. * @type: the type of variable to use
  551. * @val: current value
  552. * @min: minimum allowable value
  553. * @max: maximum allowable value
  554. *
  555. * This macro does no typechecking and uses temporary variables of type
  556. * 'type' to make all the comparisons.
  557. */
  558. #define clamp_t(type, val, min, max) ({ \
  559. type __val = (val); \
  560. type __min = (min); \
  561. type __max = (max); \
  562. __val = __val < __min ? __min: __val; \
  563. __val > __max ? __max: __val; })
  564. /**
  565. * clamp_val - return a value clamped to a given range using val's type
  566. * @val: current value
  567. * @min: minimum allowable value
  568. * @max: maximum allowable value
  569. *
  570. * This macro does no typechecking and uses temporary variables of whatever
  571. * type the input argument 'val' is. This is useful when val is an unsigned
  572. * type and min and max are literals that will otherwise be assigned a signed
  573. * integer type.
  574. */
  575. #define clamp_val(val, min, max) ({ \
  576. typeof(val) __val = (val); \
  577. typeof(val) __min = (min); \
  578. typeof(val) __max = (max); \
  579. __val = __val < __min ? __min: __val; \
  580. __val > __max ? __max: __val; })
  581. /*
  582. * swap - swap value of @a and @b
  583. */
  584. #define swap(a, b) \
  585. do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
  586. /**
  587. * container_of - cast a member of a structure out to the containing structure
  588. * @ptr: the pointer to the member.
  589. * @type: the type of the container struct this is embedded in.
  590. * @member: the name of the member within the struct.
  591. *
  592. */
  593. #define container_of(ptr, type, member) ({ \
  594. const typeof( ((type *)0)->member ) *__mptr = (ptr); \
  595. (type *)( (char *)__mptr - offsetof(type,member) );})
  596. /* Trap pasters of __FUNCTION__ at compile-time */
  597. #define __FUNCTION__ (__func__)
  598. /* This helps us to avoid #ifdef CONFIG_NUMA */
  599. #ifdef CONFIG_NUMA
  600. #define NUMA_BUILD 1
  601. #else
  602. #define NUMA_BUILD 0
  603. #endif
  604. /* This helps us avoid #ifdef CONFIG_COMPACTION */
  605. #ifdef CONFIG_COMPACTION
  606. #define COMPACTION_BUILD 1
  607. #else
  608. #define COMPACTION_BUILD 0
  609. #endif
  610. /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
  611. #ifdef CONFIG_FTRACE_MCOUNT_RECORD
  612. # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
  613. #endif
  614. extern int do_sysinfo(struct sysinfo *info);
  615. #endif /* __KERNEL__ */
  616. #endif