01bc530fbfcbe146a3395aa488d89b4b944d64b8
[deliverable/linux.git] / include / linux / kernel.h
1 #ifndef _LINUX_KERNEL_H
2 #define _LINUX_KERNEL_H
3
4
5 #include <stdarg.h>
6 #include <linux/linkage.h>
7 #include <linux/stddef.h>
8 #include <linux/types.h>
9 #include <linux/compiler.h>
10 #include <linux/bitops.h>
11 #include <linux/log2.h>
12 #include <linux/typecheck.h>
13 #include <linux/printk.h>
14 #include <linux/dynamic_debug.h>
15 #include <asm/byteorder.h>
16 #include <uapi/linux/kernel.h>
17
18 #define USHRT_MAX ((u16)(~0U))
19 #define SHRT_MAX ((s16)(USHRT_MAX>>1))
20 #define SHRT_MIN ((s16)(-SHRT_MAX - 1))
21 #define INT_MAX ((int)(~0U>>1))
22 #define INT_MIN (-INT_MAX - 1)
23 #define UINT_MAX (~0U)
24 #define LONG_MAX ((long)(~0UL>>1))
25 #define LONG_MIN (-LONG_MAX - 1)
26 #define ULONG_MAX (~0UL)
27 #define LLONG_MAX ((long long)(~0ULL>>1))
28 #define LLONG_MIN (-LLONG_MAX - 1)
29 #define ULLONG_MAX (~0ULL)
30 #define SIZE_MAX (~(size_t)0)
31
32 #define U8_MAX ((u8)~0U)
33 #define S8_MAX ((s8)(U8_MAX>>1))
34 #define S8_MIN ((s8)(-S8_MAX - 1))
35 #define U16_MAX ((u16)~0U)
36 #define S16_MAX ((s16)(U16_MAX>>1))
37 #define S16_MIN ((s16)(-S16_MAX - 1))
38 #define U32_MAX ((u32)~0U)
39 #define S32_MAX ((s32)(U32_MAX>>1))
40 #define S32_MIN ((s32)(-S32_MAX - 1))
41 #define U64_MAX ((u64)~0ULL)
42 #define S64_MAX ((s64)(U64_MAX>>1))
43 #define S64_MIN ((s64)(-S64_MAX - 1))
44
45 #define STACK_MAGIC 0xdeadbeef
46
47 #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x))
48
49 #define ALIGN(x, a) __ALIGN_KERNEL((x), (a))
50 #define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask))
51 #define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
52 #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
53
54 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
55
56 /*
57 * This looks more complex than it should be. But we need to
58 * get the type for the ~ right in round_down (it needs to be
59 * as wide as the result!), and we want to evaluate the macro
60 * arguments just once each.
61 */
62 #define __round_mask(x, y) ((__typeof__(x))((y)-1))
63 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
64 #define round_down(x, y) ((x) & ~__round_mask(x, y))
65
66 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
67 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
68 #define DIV_ROUND_UP_ULL(ll,d) \
69 ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; })
70
71 #if BITS_PER_LONG == 32
72 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
73 #else
74 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
75 #endif
76
77 /* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
78 #define roundup(x, y) ( \
79 { \
80 const typeof(y) __y = y; \
81 (((x) + (__y - 1)) / __y) * __y; \
82 } \
83 )
84 #define rounddown(x, y) ( \
85 { \
86 typeof(x) __x = (x); \
87 __x - (__x % (y)); \
88 } \
89 )
90
91 /*
92 * Divide positive or negative dividend by positive divisor and round
93 * to closest integer. Result is undefined for negative divisors and
94 * for negative dividends if the divisor variable type is unsigned.
95 */
96 #define DIV_ROUND_CLOSEST(x, divisor)( \
97 { \
98 typeof(x) __x = x; \
99 typeof(divisor) __d = divisor; \
100 (((typeof(x))-1) > 0 || \
101 ((typeof(divisor))-1) > 0 || (__x) > 0) ? \
102 (((__x) + ((__d) / 2)) / (__d)) : \
103 (((__x) - ((__d) / 2)) / (__d)); \
104 } \
105 )
106
107 /*
108 * Multiplies an integer by a fraction, while avoiding unnecessary
109 * overflow or loss of precision.
110 */
111 #define mult_frac(x, numer, denom)( \
112 { \
113 typeof(x) quot = (x) / (denom); \
114 typeof(x) rem = (x) % (denom); \
115 (quot * (numer)) + ((rem * (numer)) / (denom)); \
116 } \
117 )
118
119
120 #define _RET_IP_ (unsigned long)__builtin_return_address(0)
121 #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
122
123 #ifdef CONFIG_LBDAF
124 # include <asm/div64.h>
125 # define sector_div(a, b) do_div(a, b)
126 #else
127 # define sector_div(n, b)( \
128 { \
129 int _res; \
130 _res = (n) % (b); \
131 (n) /= (b); \
132 _res; \
133 } \
134 )
135 #endif
136
137 /**
138 * upper_32_bits - return bits 32-63 of a number
139 * @n: the number we're accessing
140 *
141 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
142 * the "right shift count >= width of type" warning when that quantity is
143 * 32-bits.
144 */
145 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
146
147 /**
148 * lower_32_bits - return bits 0-31 of a number
149 * @n: the number we're accessing
150 */
151 #define lower_32_bits(n) ((u32)(n))
152
153 struct completion;
154 struct pt_regs;
155 struct user;
156
157 #ifdef CONFIG_PREEMPT_VOLUNTARY
158 extern int _cond_resched(void);
159 # define might_resched() _cond_resched()
160 #else
161 # define might_resched() do { } while (0)
162 #endif
163
164 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
165 void __might_sleep(const char *file, int line, int preempt_offset);
166 /**
167 * might_sleep - annotation for functions that can sleep
168 *
169 * this macro will print a stack trace if it is executed in an atomic
170 * context (spinlock, irq-handler, ...).
171 *
172 * This is a useful debugging help to be able to catch problems early and not
173 * be bitten later when the calling function happens to sleep when it is not
174 * supposed to.
175 */
176 # define might_sleep() \
177 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
178 #else
179 static inline void __might_sleep(const char *file, int line,
180 int preempt_offset) { }
181 # define might_sleep() do { might_resched(); } while (0)
182 #endif
183
184 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
185
186 /*
187 * abs() handles unsigned and signed longs, ints, shorts and chars. For all
188 * input types abs() returns a signed long.
189 * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64()
190 * for those.
191 */
192 #define abs(x) ({ \
193 long ret; \
194 if (sizeof(x) == sizeof(long)) { \
195 long __x = (x); \
196 ret = (__x < 0) ? -__x : __x; \
197 } else { \
198 int __x = (x); \
199 ret = (__x < 0) ? -__x : __x; \
200 } \
201 ret; \
202 })
203
204 #define abs64(x) ({ \
205 s64 __x = (x); \
206 (__x < 0) ? -__x : __x; \
207 })
208
209 /**
210 * reciprocal_scale - "scale" a value into range [0, ep_ro)
211 * @val: value
212 * @ep_ro: right open interval endpoint
213 *
214 * Perform a "reciprocal multiplication" in order to "scale" a value into
215 * range [0, ep_ro), where the upper interval endpoint is right-open.
216 * This is useful, e.g. for accessing a index of an array containing
217 * ep_ro elements, for example. Think of it as sort of modulus, only that
218 * the result isn't that of modulo. ;) Note that if initial input is a
219 * small value, then result will return 0.
220 *
221 * Return: a result based on val in interval [0, ep_ro).
222 */
223 static inline u32 reciprocal_scale(u32 val, u32 ep_ro)
224 {
225 return (u32)(((u64) val * ep_ro) >> 32);
226 }
227
228 #if defined(CONFIG_MMU) && \
229 (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP))
230 void might_fault(void);
231 #else
232 static inline void might_fault(void) { }
233 #endif
234
235 extern struct atomic_notifier_head panic_notifier_list;
236 extern long (*panic_blink)(int state);
237 __printf(1, 2)
238 void panic(const char *fmt, ...)
239 __noreturn __cold;
240 extern void oops_enter(void);
241 extern void oops_exit(void);
242 void print_oops_end_marker(void);
243 extern int oops_may_print(void);
244 void do_exit(long error_code)
245 __noreturn;
246 void complete_and_exit(struct completion *, long)
247 __noreturn;
248
249 /* Internal, do not use. */
250 int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
251 int __must_check _kstrtol(const char *s, unsigned int base, long *res);
252
253 int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
254 int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
255
256 /**
257 * kstrtoul - convert a string to an unsigned long
258 * @s: The start of the string. The string must be null-terminated, and may also
259 * include a single newline before its terminating null. The first character
260 * may also be a plus sign, but not a minus sign.
261 * @base: The number base to use. The maximum supported base is 16. If base is
262 * given as 0, then the base of the string is automatically detected with the
263 * conventional semantics - If it begins with 0x the number will be parsed as a
264 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
265 * parsed as an octal number. Otherwise it will be parsed as a decimal.
266 * @res: Where to write the result of the conversion on success.
267 *
268 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
269 * Used as a replacement for the obsolete simple_strtoull. Return code must
270 * be checked.
271 */
272 static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
273 {
274 /*
275 * We want to shortcut function call, but
276 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
277 */
278 if (sizeof(unsigned long) == sizeof(unsigned long long) &&
279 __alignof__(unsigned long) == __alignof__(unsigned long long))
280 return kstrtoull(s, base, (unsigned long long *)res);
281 else
282 return _kstrtoul(s, base, res);
283 }
284
285 /**
286 * kstrtol - convert a string to a long
287 * @s: The start of the string. The string must be null-terminated, and may also
288 * include a single newline before its terminating null. The first character
289 * may also be a plus sign or a minus sign.
290 * @base: The number base to use. The maximum supported base is 16. If base is
291 * given as 0, then the base of the string is automatically detected with the
292 * conventional semantics - If it begins with 0x the number will be parsed as a
293 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
294 * parsed as an octal number. Otherwise it will be parsed as a decimal.
295 * @res: Where to write the result of the conversion on success.
296 *
297 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
298 * Used as a replacement for the obsolete simple_strtoull. Return code must
299 * be checked.
300 */
301 static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
302 {
303 /*
304 * We want to shortcut function call, but
305 * __builtin_types_compatible_p(long, long long) = 0.
306 */
307 if (sizeof(long) == sizeof(long long) &&
308 __alignof__(long) == __alignof__(long long))
309 return kstrtoll(s, base, (long long *)res);
310 else
311 return _kstrtol(s, base, res);
312 }
313
314 int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
315 int __must_check kstrtoint(const char *s, unsigned int base, int *res);
316
317 static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
318 {
319 return kstrtoull(s, base, res);
320 }
321
322 static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
323 {
324 return kstrtoll(s, base, res);
325 }
326
327 static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
328 {
329 return kstrtouint(s, base, res);
330 }
331
332 static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
333 {
334 return kstrtoint(s, base, res);
335 }
336
337 int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
338 int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
339 int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
340 int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
341
342 int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
343 int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
344 int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
345 int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
346 int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
347 int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
348 int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
349 int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
350 int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
351 int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
352
353 static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
354 {
355 return kstrtoull_from_user(s, count, base, res);
356 }
357
358 static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
359 {
360 return kstrtoll_from_user(s, count, base, res);
361 }
362
363 static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
364 {
365 return kstrtouint_from_user(s, count, base, res);
366 }
367
368 static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
369 {
370 return kstrtoint_from_user(s, count, base, res);
371 }
372
373 /* Obsolete, do not use. Use kstrto<foo> instead */
374
375 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
376 extern long simple_strtol(const char *,char **,unsigned int);
377 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
378 extern long long simple_strtoll(const char *,char **,unsigned int);
379
380 extern int num_to_str(char *buf, int size, unsigned long long num);
381
382 /* lib/printf utilities */
383
384 extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
385 extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
386 extern __printf(3, 4)
387 int snprintf(char *buf, size_t size, const char *fmt, ...);
388 extern __printf(3, 0)
389 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
390 extern __printf(3, 4)
391 int scnprintf(char *buf, size_t size, const char *fmt, ...);
392 extern __printf(3, 0)
393 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
394 extern __printf(2, 3)
395 char *kasprintf(gfp_t gfp, const char *fmt, ...);
396 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
397
398 extern __scanf(2, 3)
399 int sscanf(const char *, const char *, ...);
400 extern __scanf(2, 0)
401 int vsscanf(const char *, const char *, va_list);
402
403 extern int get_option(char **str, int *pint);
404 extern char *get_options(const char *str, int nints, int *ints);
405 extern unsigned long long memparse(const char *ptr, char **retptr);
406 extern bool parse_option_str(const char *str, const char *option);
407
408 extern int core_kernel_text(unsigned long addr);
409 extern int core_kernel_data(unsigned long addr);
410 extern int __kernel_text_address(unsigned long addr);
411 extern int kernel_text_address(unsigned long addr);
412 extern int func_ptr_is_kernel_text(void *ptr);
413
414 unsigned long int_sqrt(unsigned long);
415
416 extern void bust_spinlocks(int yes);
417 extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
418 extern int panic_timeout;
419 extern int panic_on_oops;
420 extern int panic_on_unrecovered_nmi;
421 extern int panic_on_io_nmi;
422 extern int sysctl_panic_on_stackoverflow;
423 /*
424 * Only to be used by arch init code. If the user over-wrote the default
425 * CONFIG_PANIC_TIMEOUT, honor it.
426 */
427 static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout)
428 {
429 if (panic_timeout == arch_default_timeout)
430 panic_timeout = timeout;
431 }
432 extern const char *print_tainted(void);
433 enum lockdep_ok {
434 LOCKDEP_STILL_OK,
435 LOCKDEP_NOW_UNRELIABLE
436 };
437 extern void add_taint(unsigned flag, enum lockdep_ok);
438 extern int test_taint(unsigned flag);
439 extern unsigned long get_taint(void);
440 extern int root_mountflags;
441
442 extern bool early_boot_irqs_disabled;
443
444 /* Values used for system_state */
445 extern enum system_states {
446 SYSTEM_BOOTING,
447 SYSTEM_RUNNING,
448 SYSTEM_HALT,
449 SYSTEM_POWER_OFF,
450 SYSTEM_RESTART,
451 } system_state;
452
453 #define TAINT_PROPRIETARY_MODULE 0
454 #define TAINT_FORCED_MODULE 1
455 #define TAINT_CPU_OUT_OF_SPEC 2
456 #define TAINT_FORCED_RMMOD 3
457 #define TAINT_MACHINE_CHECK 4
458 #define TAINT_BAD_PAGE 5
459 #define TAINT_USER 6
460 #define TAINT_DIE 7
461 #define TAINT_OVERRIDDEN_ACPI_TABLE 8
462 #define TAINT_WARN 9
463 #define TAINT_CRAP 10
464 #define TAINT_FIRMWARE_WORKAROUND 11
465 #define TAINT_OOT_MODULE 12
466 #define TAINT_UNSIGNED_MODULE 13
467 #define TAINT_SOFTLOCKUP 14
468
469 extern const char hex_asc[];
470 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
471 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
472
473 static inline char *hex_byte_pack(char *buf, u8 byte)
474 {
475 *buf++ = hex_asc_hi(byte);
476 *buf++ = hex_asc_lo(byte);
477 return buf;
478 }
479
480 extern const char hex_asc_upper[];
481 #define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)]
482 #define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4]
483
484 static inline char *hex_byte_pack_upper(char *buf, u8 byte)
485 {
486 *buf++ = hex_asc_upper_hi(byte);
487 *buf++ = hex_asc_upper_lo(byte);
488 return buf;
489 }
490
491 extern int hex_to_bin(char ch);
492 extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
493 extern char *bin2hex(char *dst, const void *src, size_t count);
494
495 bool mac_pton(const char *s, u8 *mac);
496
497 /*
498 * General tracing related utility functions - trace_printk(),
499 * tracing_on/tracing_off and tracing_start()/tracing_stop
500 *
501 * Use tracing_on/tracing_off when you want to quickly turn on or off
502 * tracing. It simply enables or disables the recording of the trace events.
503 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
504 * file, which gives a means for the kernel and userspace to interact.
505 * Place a tracing_off() in the kernel where you want tracing to end.
506 * From user space, examine the trace, and then echo 1 > tracing_on
507 * to continue tracing.
508 *
509 * tracing_stop/tracing_start has slightly more overhead. It is used
510 * by things like suspend to ram where disabling the recording of the
511 * trace is not enough, but tracing must actually stop because things
512 * like calling smp_processor_id() may crash the system.
513 *
514 * Most likely, you want to use tracing_on/tracing_off.
515 */
516 #ifdef CONFIG_RING_BUFFER
517 /* trace_off_permanent stops recording with no way to bring it back */
518 void tracing_off_permanent(void);
519 #else
520 static inline void tracing_off_permanent(void) { }
521 #endif
522
523 enum ftrace_dump_mode {
524 DUMP_NONE,
525 DUMP_ALL,
526 DUMP_ORIG,
527 };
528
529 #ifdef CONFIG_TRACING
530 void tracing_on(void);
531 void tracing_off(void);
532 int tracing_is_on(void);
533 void tracing_snapshot(void);
534 void tracing_snapshot_alloc(void);
535
536 extern void tracing_start(void);
537 extern void tracing_stop(void);
538
539 static inline __printf(1, 2)
540 void ____trace_printk_check_format(const char *fmt, ...)
541 {
542 }
543 #define __trace_printk_check_format(fmt, args...) \
544 do { \
545 if (0) \
546 ____trace_printk_check_format(fmt, ##args); \
547 } while (0)
548
549 /**
550 * trace_printk - printf formatting in the ftrace buffer
551 * @fmt: the printf format for printing
552 *
553 * Note: __trace_printk is an internal function for trace_printk and
554 * the @ip is passed in via the trace_printk macro.
555 *
556 * This function allows a kernel developer to debug fast path sections
557 * that printk is not appropriate for. By scattering in various
558 * printk like tracing in the code, a developer can quickly see
559 * where problems are occurring.
560 *
561 * This is intended as a debugging tool for the developer only.
562 * Please refrain from leaving trace_printks scattered around in
563 * your code. (Extra memory is used for special buffers that are
564 * allocated when trace_printk() is used)
565 *
566 * A little optization trick is done here. If there's only one
567 * argument, there's no need to scan the string for printf formats.
568 * The trace_puts() will suffice. But how can we take advantage of
569 * using trace_puts() when trace_printk() has only one argument?
570 * By stringifying the args and checking the size we can tell
571 * whether or not there are args. __stringify((__VA_ARGS__)) will
572 * turn into "()\0" with a size of 3 when there are no args, anything
573 * else will be bigger. All we need to do is define a string to this,
574 * and then take its size and compare to 3. If it's bigger, use
575 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just
576 * let gcc optimize the rest.
577 */
578
579 #define trace_printk(fmt, ...) \
580 do { \
581 char _______STR[] = __stringify((__VA_ARGS__)); \
582 if (sizeof(_______STR) > 3) \
583 do_trace_printk(fmt, ##__VA_ARGS__); \
584 else \
585 trace_puts(fmt); \
586 } while (0)
587
588 #define do_trace_printk(fmt, args...) \
589 do { \
590 static const char *trace_printk_fmt \
591 __attribute__((section("__trace_printk_fmt"))) = \
592 __builtin_constant_p(fmt) ? fmt : NULL; \
593 \
594 __trace_printk_check_format(fmt, ##args); \
595 \
596 if (__builtin_constant_p(fmt)) \
597 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
598 else \
599 __trace_printk(_THIS_IP_, fmt, ##args); \
600 } while (0)
601
602 extern __printf(2, 3)
603 int __trace_bprintk(unsigned long ip, const char *fmt, ...);
604
605 extern __printf(2, 3)
606 int __trace_printk(unsigned long ip, const char *fmt, ...);
607
608 /**
609 * trace_puts - write a string into the ftrace buffer
610 * @str: the string to record
611 *
612 * Note: __trace_bputs is an internal function for trace_puts and
613 * the @ip is passed in via the trace_puts macro.
614 *
615 * This is similar to trace_printk() but is made for those really fast
616 * paths that a developer wants the least amount of "Heisenbug" affects,
617 * where the processing of the print format is still too much.
618 *
619 * This function allows a kernel developer to debug fast path sections
620 * that printk is not appropriate for. By scattering in various
621 * printk like tracing in the code, a developer can quickly see
622 * where problems are occurring.
623 *
624 * This is intended as a debugging tool for the developer only.
625 * Please refrain from leaving trace_puts scattered around in
626 * your code. (Extra memory is used for special buffers that are
627 * allocated when trace_puts() is used)
628 *
629 * Returns: 0 if nothing was written, positive # if string was.
630 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used)
631 */
632
633 #define trace_puts(str) ({ \
634 static const char *trace_printk_fmt \
635 __attribute__((section("__trace_printk_fmt"))) = \
636 __builtin_constant_p(str) ? str : NULL; \
637 \
638 if (__builtin_constant_p(str)) \
639 __trace_bputs(_THIS_IP_, trace_printk_fmt); \
640 else \
641 __trace_puts(_THIS_IP_, str, strlen(str)); \
642 })
643 extern int __trace_bputs(unsigned long ip, const char *str);
644 extern int __trace_puts(unsigned long ip, const char *str, int size);
645
646 extern void trace_dump_stack(int skip);
647
648 /*
649 * The double __builtin_constant_p is because gcc will give us an error
650 * if we try to allocate the static variable to fmt if it is not a
651 * constant. Even with the outer if statement.
652 */
653 #define ftrace_vprintk(fmt, vargs) \
654 do { \
655 if (__builtin_constant_p(fmt)) { \
656 static const char *trace_printk_fmt \
657 __attribute__((section("__trace_printk_fmt"))) = \
658 __builtin_constant_p(fmt) ? fmt : NULL; \
659 \
660 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
661 } else \
662 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
663 } while (0)
664
665 extern int
666 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
667
668 extern int
669 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
670
671 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
672 #else
673 static inline void tracing_start(void) { }
674 static inline void tracing_stop(void) { }
675 static inline void trace_dump_stack(int skip) { }
676
677 static inline void tracing_on(void) { }
678 static inline void tracing_off(void) { }
679 static inline int tracing_is_on(void) { return 0; }
680 static inline void tracing_snapshot(void) { }
681 static inline void tracing_snapshot_alloc(void) { }
682
683 static inline __printf(1, 2)
684 int trace_printk(const char *fmt, ...)
685 {
686 return 0;
687 }
688 static inline int
689 ftrace_vprintk(const char *fmt, va_list ap)
690 {
691 return 0;
692 }
693 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
694 #endif /* CONFIG_TRACING */
695
696 /*
697 * min()/max()/clamp() macros that also do
698 * strict type-checking.. See the
699 * "unnecessary" pointer comparison.
700 */
701 #define min(x, y) ({ \
702 typeof(x) _min1 = (x); \
703 typeof(y) _min2 = (y); \
704 (void) (&_min1 == &_min2); \
705 _min1 < _min2 ? _min1 : _min2; })
706
707 #define max(x, y) ({ \
708 typeof(x) _max1 = (x); \
709 typeof(y) _max2 = (y); \
710 (void) (&_max1 == &_max2); \
711 _max1 > _max2 ? _max1 : _max2; })
712
713 #define min3(x, y, z) min((typeof(x))min(x, y), z)
714 #define max3(x, y, z) max((typeof(x))max(x, y), z)
715
716 /**
717 * min_not_zero - return the minimum that is _not_ zero, unless both are zero
718 * @x: value1
719 * @y: value2
720 */
721 #define min_not_zero(x, y) ({ \
722 typeof(x) __x = (x); \
723 typeof(y) __y = (y); \
724 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
725
726 /**
727 * clamp - return a value clamped to a given range with strict typechecking
728 * @val: current value
729 * @lo: lowest allowable value
730 * @hi: highest allowable value
731 *
732 * This macro does strict typechecking of lo/hi to make sure they are of the
733 * same type as val. See the unnecessary pointer comparisons.
734 */
735 #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
736
737 /*
738 * ..and if you can't take the strict
739 * types, you can specify one yourself.
740 *
741 * Or not use min/max/clamp at all, of course.
742 */
743 #define min_t(type, x, y) ({ \
744 type __min1 = (x); \
745 type __min2 = (y); \
746 __min1 < __min2 ? __min1: __min2; })
747
748 #define max_t(type, x, y) ({ \
749 type __max1 = (x); \
750 type __max2 = (y); \
751 __max1 > __max2 ? __max1: __max2; })
752
753 /**
754 * clamp_t - return a value clamped to a given range using a given type
755 * @type: the type of variable to use
756 * @val: current value
757 * @lo: minimum allowable value
758 * @hi: maximum allowable value
759 *
760 * This macro does no typechecking and uses temporary variables of type
761 * 'type' to make all the comparisons.
762 */
763 #define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi)
764
765 /**
766 * clamp_val - return a value clamped to a given range using val's type
767 * @val: current value
768 * @lo: minimum allowable value
769 * @hi: maximum allowable value
770 *
771 * This macro does no typechecking and uses temporary variables of whatever
772 * type the input argument 'val' is. This is useful when val is an unsigned
773 * type and min and max are literals that will otherwise be assigned a signed
774 * integer type.
775 */
776 #define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi)
777
778
779 /*
780 * swap - swap value of @a and @b
781 */
782 #define swap(a, b) \
783 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
784
785 /**
786 * container_of - cast a member of a structure out to the containing structure
787 * @ptr: the pointer to the member.
788 * @type: the type of the container struct this is embedded in.
789 * @member: the name of the member within the struct.
790 *
791 */
792 #define container_of(ptr, type, member) ({ \
793 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
794 (type *)( (char *)__mptr - offsetof(type,member) );})
795
796 /* Trap pasters of __FUNCTION__ at compile-time */
797 #define __FUNCTION__ (__func__)
798
799 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
800 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
801 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
802 #endif
803
804 /* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */
805 #define VERIFY_OCTAL_PERMISSIONS(perms) \
806 (BUILD_BUG_ON_ZERO((perms) < 0) + \
807 BUILD_BUG_ON_ZERO((perms) > 0777) + \
808 /* User perms >= group perms >= other perms */ \
809 BUILD_BUG_ON_ZERO(((perms) >> 6) < (((perms) >> 3) & 7)) + \
810 BUILD_BUG_ON_ZERO((((perms) >> 3) & 7) < ((perms) & 7)) + \
811 /* Other writable? Generally considered a bad idea. */ \
812 BUILD_BUG_ON_ZERO((perms) & 2) + \
813 (perms))
814 #endif
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