kernel.h 18 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. /* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
  51. #define roundup(x, y) ( \
  52. { \
  53. const typeof(y) __y = y; \
  54. (((x) + (__y - 1)) / __y) * __y; \
  55. } \
  56. )
  57. #define rounddown(x, y) ( \
  58. { \
  59. typeof(x) __x = (x); \
  60. __x - (__x % (y)); \
  61. } \
  62. )
  63. #define DIV_ROUND_CLOSEST(x, divisor)( \
  64. { \
  65. typeof(divisor) __divisor = divisor; \
  66. (((x) + ((__divisor) / 2)) / (__divisor)); \
  67. } \
  68. )
  69. #define _RET_IP_ (unsigned long)__builtin_return_address(0)
  70. #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
  71. #ifdef CONFIG_LBDAF
  72. # include <asm/div64.h>
  73. # define sector_div(a, b) do_div(a, b)
  74. #else
  75. # define sector_div(n, b)( \
  76. { \
  77. int _res; \
  78. _res = (n) % (b); \
  79. (n) /= (b); \
  80. _res; \
  81. } \
  82. )
  83. #endif
  84. /**
  85. * upper_32_bits - return bits 32-63 of a number
  86. * @n: the number we're accessing
  87. *
  88. * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
  89. * the "right shift count >= width of type" warning when that quantity is
  90. * 32-bits.
  91. */
  92. #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
  93. /**
  94. * lower_32_bits - return bits 0-31 of a number
  95. * @n: the number we're accessing
  96. */
  97. #define lower_32_bits(n) ((u32)(n))
  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(const 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(const char *file, int line,
  123. int preempt_offset) { }
  124. # define might_sleep() do { might_resched(); } while (0)
  125. #endif
  126. #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
  127. #define abs(x) ({ \
  128. long __x = (x); \
  129. (__x < 0) ? -__x : __x; \
  130. })
  131. #define abs64(x) ({ \
  132. s64 __x = (x); \
  133. (__x < 0) ? -__x : __x; \
  134. })
  135. #ifdef CONFIG_PROVE_LOCKING
  136. void might_fault(void);
  137. #else
  138. static inline void might_fault(void)
  139. {
  140. might_sleep();
  141. }
  142. #endif
  143. extern struct atomic_notifier_head panic_notifier_list;
  144. extern long (*panic_blink)(int state);
  145. NORET_TYPE void panic(const char * fmt, ...)
  146. __attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
  147. extern void oops_enter(void);
  148. extern void oops_exit(void);
  149. void print_oops_end_marker(void);
  150. extern int oops_may_print(void);
  151. NORET_TYPE void do_exit(long error_code)
  152. ATTRIB_NORET;
  153. NORET_TYPE void complete_and_exit(struct completion *, long)
  154. ATTRIB_NORET;
  155. extern unsigned long simple_strtoul(const char *,char **,unsigned int);
  156. extern long simple_strtol(const char *,char **,unsigned int);
  157. extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
  158. extern long long simple_strtoll(const char *,char **,unsigned int);
  159. extern int __must_check strict_strtoul(const char *, unsigned int, unsigned long *);
  160. extern int __must_check strict_strtol(const char *, unsigned int, long *);
  161. extern int __must_check strict_strtoull(const char *, unsigned int, unsigned long long *);
  162. extern int __must_check strict_strtoll(const char *, unsigned int, long long *);
  163. extern int sprintf(char * buf, const char * fmt, ...)
  164. __attribute__ ((format (printf, 2, 3)));
  165. extern int vsprintf(char *buf, const char *, va_list)
  166. __attribute__ ((format (printf, 2, 0)));
  167. extern int snprintf(char * buf, size_t size, const char * fmt, ...)
  168. __attribute__ ((format (printf, 3, 4)));
  169. extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
  170. __attribute__ ((format (printf, 3, 0)));
  171. extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
  172. __attribute__ ((format (printf, 3, 4)));
  173. extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
  174. __attribute__ ((format (printf, 3, 0)));
  175. extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
  176. __attribute__ ((format (printf, 2, 3)));
  177. extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
  178. extern int sscanf(const char *, const char *, ...)
  179. __attribute__ ((format (scanf, 2, 3)));
  180. extern int vsscanf(const char *, const char *, va_list)
  181. __attribute__ ((format (scanf, 2, 0)));
  182. extern int get_option(char **str, int *pint);
  183. extern char *get_options(const char *str, int nints, int *ints);
  184. extern unsigned long long memparse(const char *ptr, char **retptr);
  185. extern int core_kernel_text(unsigned long addr);
  186. extern int __kernel_text_address(unsigned long addr);
  187. extern int kernel_text_address(unsigned long addr);
  188. extern int func_ptr_is_kernel_text(void *ptr);
  189. struct pid;
  190. extern struct pid *session_of_pgrp(struct pid *pgrp);
  191. unsigned long int_sqrt(unsigned long);
  192. extern void bust_spinlocks(int yes);
  193. extern void wake_up_klogd(void);
  194. extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
  195. extern int panic_timeout;
  196. extern int panic_on_oops;
  197. extern int panic_on_unrecovered_nmi;
  198. extern int panic_on_io_nmi;
  199. extern const char *print_tainted(void);
  200. extern void add_taint(unsigned flag);
  201. extern int test_taint(unsigned flag);
  202. extern unsigned long get_taint(void);
  203. extern int root_mountflags;
  204. /* Values used for system_state */
  205. extern enum system_states {
  206. SYSTEM_BOOTING,
  207. SYSTEM_RUNNING,
  208. SYSTEM_HALT,
  209. SYSTEM_POWER_OFF,
  210. SYSTEM_RESTART,
  211. SYSTEM_SUSPEND_DISK,
  212. } system_state;
  213. #define TAINT_PROPRIETARY_MODULE 0
  214. #define TAINT_FORCED_MODULE 1
  215. #define TAINT_UNSAFE_SMP 2
  216. #define TAINT_FORCED_RMMOD 3
  217. #define TAINT_MACHINE_CHECK 4
  218. #define TAINT_BAD_PAGE 5
  219. #define TAINT_USER 6
  220. #define TAINT_DIE 7
  221. #define TAINT_OVERRIDDEN_ACPI_TABLE 8
  222. #define TAINT_WARN 9
  223. #define TAINT_CRAP 10
  224. #define TAINT_FIRMWARE_WORKAROUND 11
  225. extern const char hex_asc[];
  226. #define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
  227. #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
  228. static inline char *pack_hex_byte(char *buf, u8 byte)
  229. {
  230. *buf++ = hex_asc_hi(byte);
  231. *buf++ = hex_asc_lo(byte);
  232. return buf;
  233. }
  234. extern int hex_to_bin(char ch);
  235. extern void hex2bin(u8 *dst, const char *src, size_t count);
  236. /*
  237. * General tracing related utility functions - trace_printk(),
  238. * tracing_on/tracing_off and tracing_start()/tracing_stop
  239. *
  240. * Use tracing_on/tracing_off when you want to quickly turn on or off
  241. * tracing. It simply enables or disables the recording of the trace events.
  242. * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
  243. * file, which gives a means for the kernel and userspace to interact.
  244. * Place a tracing_off() in the kernel where you want tracing to end.
  245. * From user space, examine the trace, and then echo 1 > tracing_on
  246. * to continue tracing.
  247. *
  248. * tracing_stop/tracing_start has slightly more overhead. It is used
  249. * by things like suspend to ram where disabling the recording of the
  250. * trace is not enough, but tracing must actually stop because things
  251. * like calling smp_processor_id() may crash the system.
  252. *
  253. * Most likely, you want to use tracing_on/tracing_off.
  254. */
  255. #ifdef CONFIG_RING_BUFFER
  256. void tracing_on(void);
  257. void tracing_off(void);
  258. /* trace_off_permanent stops recording with no way to bring it back */
  259. void tracing_off_permanent(void);
  260. int tracing_is_on(void);
  261. #else
  262. static inline void tracing_on(void) { }
  263. static inline void tracing_off(void) { }
  264. static inline void tracing_off_permanent(void) { }
  265. static inline int tracing_is_on(void) { return 0; }
  266. #endif
  267. enum ftrace_dump_mode {
  268. DUMP_NONE,
  269. DUMP_ALL,
  270. DUMP_ORIG,
  271. };
  272. #ifdef CONFIG_TRACING
  273. extern void tracing_start(void);
  274. extern void tracing_stop(void);
  275. extern void ftrace_off_permanent(void);
  276. static inline void __attribute__ ((format (printf, 1, 2)))
  277. ____trace_printk_check_format(const char *fmt, ...)
  278. {
  279. }
  280. #define __trace_printk_check_format(fmt, args...) \
  281. do { \
  282. if (0) \
  283. ____trace_printk_check_format(fmt, ##args); \
  284. } while (0)
  285. /**
  286. * trace_printk - printf formatting in the ftrace buffer
  287. * @fmt: the printf format for printing
  288. *
  289. * Note: __trace_printk is an internal function for trace_printk and
  290. * the @ip is passed in via the trace_printk macro.
  291. *
  292. * This function allows a kernel developer to debug fast path sections
  293. * that printk is not appropriate for. By scattering in various
  294. * printk like tracing in the code, a developer can quickly see
  295. * where problems are occurring.
  296. *
  297. * This is intended as a debugging tool for the developer only.
  298. * Please refrain from leaving trace_printks scattered around in
  299. * your code.
  300. */
  301. #define trace_printk(fmt, args...) \
  302. do { \
  303. __trace_printk_check_format(fmt, ##args); \
  304. if (__builtin_constant_p(fmt)) { \
  305. static const char *trace_printk_fmt \
  306. __attribute__((section("__trace_printk_fmt"))) = \
  307. __builtin_constant_p(fmt) ? fmt : NULL; \
  308. \
  309. __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
  310. } else \
  311. __trace_printk(_THIS_IP_, fmt, ##args); \
  312. } while (0)
  313. extern int
  314. __trace_bprintk(unsigned long ip, const char *fmt, ...)
  315. __attribute__ ((format (printf, 2, 3)));
  316. extern int
  317. __trace_printk(unsigned long ip, const char *fmt, ...)
  318. __attribute__ ((format (printf, 2, 3)));
  319. extern void trace_dump_stack(void);
  320. /*
  321. * The double __builtin_constant_p is because gcc will give us an error
  322. * if we try to allocate the static variable to fmt if it is not a
  323. * constant. Even with the outer if statement.
  324. */
  325. #define ftrace_vprintk(fmt, vargs) \
  326. do { \
  327. if (__builtin_constant_p(fmt)) { \
  328. static const char *trace_printk_fmt \
  329. __attribute__((section("__trace_printk_fmt"))) = \
  330. __builtin_constant_p(fmt) ? fmt : NULL; \
  331. \
  332. __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
  333. } else \
  334. __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
  335. } while (0)
  336. extern int
  337. __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
  338. extern int
  339. __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
  340. extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
  341. #else
  342. static inline int
  343. trace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
  344. static inline void tracing_start(void) { }
  345. static inline void tracing_stop(void) { }
  346. static inline void ftrace_off_permanent(void) { }
  347. static inline void trace_dump_stack(void) { }
  348. static inline int
  349. trace_printk(const char *fmt, ...)
  350. {
  351. return 0;
  352. }
  353. static inline int
  354. ftrace_vprintk(const char *fmt, va_list ap)
  355. {
  356. return 0;
  357. }
  358. static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
  359. #endif /* CONFIG_TRACING */
  360. /*
  361. * min()/max()/clamp() macros that also do
  362. * strict type-checking.. See the
  363. * "unnecessary" pointer comparison.
  364. */
  365. #define min(x, y) ({ \
  366. typeof(x) _min1 = (x); \
  367. typeof(y) _min2 = (y); \
  368. (void) (&_min1 == &_min2); \
  369. _min1 < _min2 ? _min1 : _min2; })
  370. #define max(x, y) ({ \
  371. typeof(x) _max1 = (x); \
  372. typeof(y) _max2 = (y); \
  373. (void) (&_max1 == &_max2); \
  374. _max1 > _max2 ? _max1 : _max2; })
  375. #define min3(x, y, z) ({ \
  376. typeof(x) _min1 = (x); \
  377. typeof(y) _min2 = (y); \
  378. typeof(z) _min3 = (z); \
  379. (void) (&_min1 == &_min2); \
  380. (void) (&_min1 == &_min3); \
  381. _min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \
  382. (_min2 < _min3 ? _min2 : _min3); })
  383. #define max3(x, y, z) ({ \
  384. typeof(x) _max1 = (x); \
  385. typeof(y) _max2 = (y); \
  386. typeof(z) _max3 = (z); \
  387. (void) (&_max1 == &_max2); \
  388. (void) (&_max1 == &_max3); \
  389. _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \
  390. (_max2 > _max3 ? _max2 : _max3); })
  391. /**
  392. * min_not_zero - return the minimum that is _not_ zero, unless both are zero
  393. * @x: value1
  394. * @y: value2
  395. */
  396. #define min_not_zero(x, y) ({ \
  397. typeof(x) __x = (x); \
  398. typeof(y) __y = (y); \
  399. __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
  400. /**
  401. * clamp - return a value clamped to a given range with strict typechecking
  402. * @val: current value
  403. * @min: minimum allowable value
  404. * @max: maximum allowable value
  405. *
  406. * This macro does strict typechecking of min/max to make sure they are of the
  407. * same type as val. See the unnecessary pointer comparisons.
  408. */
  409. #define clamp(val, min, max) ({ \
  410. typeof(val) __val = (val); \
  411. typeof(min) __min = (min); \
  412. typeof(max) __max = (max); \
  413. (void) (&__val == &__min); \
  414. (void) (&__val == &__max); \
  415. __val = __val < __min ? __min: __val; \
  416. __val > __max ? __max: __val; })
  417. /*
  418. * ..and if you can't take the strict
  419. * types, you can specify one yourself.
  420. *
  421. * Or not use min/max/clamp at all, of course.
  422. */
  423. #define min_t(type, x, y) ({ \
  424. type __min1 = (x); \
  425. type __min2 = (y); \
  426. __min1 < __min2 ? __min1: __min2; })
  427. #define max_t(type, x, y) ({ \
  428. type __max1 = (x); \
  429. type __max2 = (y); \
  430. __max1 > __max2 ? __max1: __max2; })
  431. /**
  432. * clamp_t - return a value clamped to a given range using a given type
  433. * @type: the type of variable to use
  434. * @val: current value
  435. * @min: minimum allowable value
  436. * @max: maximum allowable value
  437. *
  438. * This macro does no typechecking and uses temporary variables of type
  439. * 'type' to make all the comparisons.
  440. */
  441. #define clamp_t(type, val, min, max) ({ \
  442. type __val = (val); \
  443. type __min = (min); \
  444. type __max = (max); \
  445. __val = __val < __min ? __min: __val; \
  446. __val > __max ? __max: __val; })
  447. /**
  448. * clamp_val - return a value clamped to a given range using val's type
  449. * @val: current value
  450. * @min: minimum allowable value
  451. * @max: maximum allowable value
  452. *
  453. * This macro does no typechecking and uses temporary variables of whatever
  454. * type the input argument 'val' is. This is useful when val is an unsigned
  455. * type and min and max are literals that will otherwise be assigned a signed
  456. * integer type.
  457. */
  458. #define clamp_val(val, min, max) ({ \
  459. typeof(val) __val = (val); \
  460. typeof(val) __min = (min); \
  461. typeof(val) __max = (max); \
  462. __val = __val < __min ? __min: __val; \
  463. __val > __max ? __max: __val; })
  464. /*
  465. * swap - swap value of @a and @b
  466. */
  467. #define swap(a, b) \
  468. do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
  469. /**
  470. * container_of - cast a member of a structure out to the containing structure
  471. * @ptr: the pointer to the member.
  472. * @type: the type of the container struct this is embedded in.
  473. * @member: the name of the member within the struct.
  474. *
  475. */
  476. #define container_of(ptr, type, member) ({ \
  477. const typeof( ((type *)0)->member ) *__mptr = (ptr); \
  478. (type *)( (char *)__mptr - offsetof(type,member) );})
  479. struct sysinfo;
  480. extern int do_sysinfo(struct sysinfo *info);
  481. #endif /* __KERNEL__ */
  482. #define SI_LOAD_SHIFT 16
  483. struct sysinfo {
  484. long uptime; /* Seconds since boot */
  485. unsigned long loads[3]; /* 1, 5, and 15 minute load averages */
  486. unsigned long totalram; /* Total usable main memory size */
  487. unsigned long freeram; /* Available memory size */
  488. unsigned long sharedram; /* Amount of shared memory */
  489. unsigned long bufferram; /* Memory used by buffers */
  490. unsigned long totalswap; /* Total swap space size */
  491. unsigned long freeswap; /* swap space still available */
  492. unsigned short procs; /* Number of current processes */
  493. unsigned short pad; /* explicit padding for m68k */
  494. unsigned long totalhigh; /* Total high memory size */
  495. unsigned long freehigh; /* Available high memory size */
  496. unsigned int mem_unit; /* Memory unit size in bytes */
  497. char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
  498. };
  499. /* Force a compilation error if condition is true */
  500. #define BUILD_BUG_ON(condition) ((void)BUILD_BUG_ON_ZERO(condition))
  501. /* Force a compilation error if condition is constant and true */
  502. #define MAYBE_BUILD_BUG_ON(cond) ((void)sizeof(char[1 - 2 * !!(cond)]))
  503. /* Force a compilation error if a constant expression is not a power of 2 */
  504. #define BUILD_BUG_ON_NOT_POWER_OF_2(n) \
  505. BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
  506. /* Force a compilation error if condition is true, but also produce a
  507. result (of value 0 and type size_t), so the expression can be used
  508. e.g. in a structure initializer (or where-ever else comma expressions
  509. aren't permitted). */
  510. #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
  511. #define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
  512. /* Trap pasters of __FUNCTION__ at compile-time */
  513. #define __FUNCTION__ (__func__)
  514. /* This helps us to avoid #ifdef CONFIG_NUMA */
  515. #ifdef CONFIG_NUMA
  516. #define NUMA_BUILD 1
  517. #else
  518. #define NUMA_BUILD 0
  519. #endif
  520. /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
  521. #ifdef CONFIG_FTRACE_MCOUNT_RECORD
  522. # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
  523. #endif
  524. #endif