projects/linux·blob v3.15 · refs

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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
153struct completion;
154struct pt_regs;
155struct user;
156
157#ifdef CONFIG_PREEMPT_VOLUNTARY
158extern 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 */
223static 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))
230void might_fault(void);
231#else
232static inline void might_fault(void) { }
233#endif
234
235extern struct atomic_notifier_head panic_notifier_list;
236extern long (*panic_blink)(int state);
237__printf(1, 2)
238void panic(const char *fmt, ...)
239 __noreturn __cold;
240extern void oops_enter(void);
241extern void oops_exit(void);
242void print_oops_end_marker(void);
243extern int oops_may_print(void);
244void do_exit(long error_code)
245 __noreturn;
246void complete_and_exit(struct completion *, long)
247 __noreturn;
248
249/* Internal, do not use. */
250int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
251int __must_check _kstrtol(const char *s, unsigned int base, long *res);
252
253int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
254int __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*/
272static 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 */
301static 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
314int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
315int __must_check kstrtoint(const char *s, unsigned int base, int *res);
316
317static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
318{
319 return kstrtoull(s, base, res);
320}
321
322static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
323{
324 return kstrtoll(s, base, res);
325}
326
327static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
328{
329 return kstrtouint(s, base, res);
330}
331
332static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
333{
334 return kstrtoint(s, base, res);
335}
336
337int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
338int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
339int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
340int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
341
342int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
343int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
344int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
345int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
346int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
347int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
348int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
349int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
350int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
351int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
352
353static 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
358static 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
363static 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
368static 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
375extern unsigned long simple_strtoul(const char *,char **,unsigned int);
376extern long simple_strtol(const char *,char **,unsigned int);
377extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
378extern long long simple_strtoll(const char *,char **,unsigned int);
379#define strict_strtoul kstrtoul
380#define strict_strtol kstrtol
381#define strict_strtoull kstrtoull
382#define strict_strtoll kstrtoll
383
384extern int num_to_str(char *buf, int size, unsigned long long num);
385
386/* lib/printf utilities */
387
388extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
389extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
390extern __printf(3, 4)
391int snprintf(char *buf, size_t size, const char *fmt, ...);
392extern __printf(3, 0)
393int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
394extern __printf(3, 4)
395int scnprintf(char *buf, size_t size, const char *fmt, ...);
396extern __printf(3, 0)
397int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
398extern __printf(2, 3)
399char *kasprintf(gfp_t gfp, const char *fmt, ...);
400extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
401
402extern __scanf(2, 3)
403int sscanf(const char *, const char *, ...);
404extern __scanf(2, 0)
405int vsscanf(const char *, const char *, va_list);
406
407extern int get_option(char **str, int *pint);
408extern char *get_options(const char *str, int nints, int *ints);
409extern unsigned long long memparse(const char *ptr, char **retptr);
410
411extern int core_kernel_text(unsigned long addr);
412extern int core_kernel_data(unsigned long addr);
413extern int __kernel_text_address(unsigned long addr);
414extern int kernel_text_address(unsigned long addr);
415extern int func_ptr_is_kernel_text(void *ptr);
416
417struct pid;
418extern struct pid *session_of_pgrp(struct pid *pgrp);
419
420unsigned long int_sqrt(unsigned long);
421
422extern void bust_spinlocks(int yes);
423extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
424extern int panic_timeout;
425extern int panic_on_oops;
426extern int panic_on_unrecovered_nmi;
427extern int panic_on_io_nmi;
428extern int sysctl_panic_on_stackoverflow;
429/*
430 * Only to be used by arch init code. If the user over-wrote the default
431 * CONFIG_PANIC_TIMEOUT, honor it.
432 */
433static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout)
434{
435 if (panic_timeout == arch_default_timeout)
436 panic_timeout = timeout;
437}
438extern const char *print_tainted(void);
439enum lockdep_ok {
440 LOCKDEP_STILL_OK,
441 LOCKDEP_NOW_UNRELIABLE
442};
443extern void add_taint(unsigned flag, enum lockdep_ok);
444extern int test_taint(unsigned flag);
445extern unsigned long get_taint(void);
446extern int root_mountflags;
447
448extern bool early_boot_irqs_disabled;
449
450/* Values used for system_state */
451extern enum system_states {
452 SYSTEM_BOOTING,
453 SYSTEM_RUNNING,
454 SYSTEM_HALT,
455 SYSTEM_POWER_OFF,
456 SYSTEM_RESTART,
457} system_state;
458
459#define TAINT_PROPRIETARY_MODULE 0
460#define TAINT_FORCED_MODULE 1
461#define TAINT_CPU_OUT_OF_SPEC 2
462#define TAINT_FORCED_RMMOD 3
463#define TAINT_MACHINE_CHECK 4
464#define TAINT_BAD_PAGE 5
465#define TAINT_USER 6
466#define TAINT_DIE 7
467#define TAINT_OVERRIDDEN_ACPI_TABLE 8
468#define TAINT_WARN 9
469#define TAINT_CRAP 10
470#define TAINT_FIRMWARE_WORKAROUND 11
471#define TAINT_OOT_MODULE 12
472#define TAINT_UNSIGNED_MODULE 13
473
474extern const char hex_asc[];
475#define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
476#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
477
478static inline char *hex_byte_pack(char *buf, u8 byte)
479{
480 *buf++ = hex_asc_hi(byte);
481 *buf++ = hex_asc_lo(byte);
482 return buf;
483}
484
485extern const char hex_asc_upper[];
486#define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)]
487#define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4]
488
489static inline char *hex_byte_pack_upper(char *buf, u8 byte)
490{
491 *buf++ = hex_asc_upper_hi(byte);
492 *buf++ = hex_asc_upper_lo(byte);
493 return buf;
494}
495
496static inline char * __deprecated pack_hex_byte(char *buf, u8 byte)
497{
498 return hex_byte_pack(buf, byte);
499}
500
501extern int hex_to_bin(char ch);
502extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
503
504int mac_pton(const char *s, u8 *mac);
505
506/*
507 * General tracing related utility functions - trace_printk(),
508 * tracing_on/tracing_off and tracing_start()/tracing_stop
509 *
510 * Use tracing_on/tracing_off when you want to quickly turn on or off
511 * tracing. It simply enables or disables the recording of the trace events.
512 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
513 * file, which gives a means for the kernel and userspace to interact.
514 * Place a tracing_off() in the kernel where you want tracing to end.
515 * From user space, examine the trace, and then echo 1 > tracing_on
516 * to continue tracing.
517 *
518 * tracing_stop/tracing_start has slightly more overhead. It is used
519 * by things like suspend to ram where disabling the recording of the
520 * trace is not enough, but tracing must actually stop because things
521 * like calling smp_processor_id() may crash the system.
522 *
523 * Most likely, you want to use tracing_on/tracing_off.
524 */
525#ifdef CONFIG_RING_BUFFER
526/* trace_off_permanent stops recording with no way to bring it back */
527void tracing_off_permanent(void);
528#else
529static inline void tracing_off_permanent(void) { }
530#endif
531
532enum ftrace_dump_mode {
533 DUMP_NONE,
534 DUMP_ALL,
535 DUMP_ORIG,
536};
537
538#ifdef CONFIG_TRACING
539void tracing_on(void);
540void tracing_off(void);
541int tracing_is_on(void);
542void tracing_snapshot(void);
543void tracing_snapshot_alloc(void);
544
545extern void tracing_start(void);
546extern void tracing_stop(void);
547
548static inline __printf(1, 2)
549void ____trace_printk_check_format(const char *fmt, ...)
550{
551}
552#define __trace_printk_check_format(fmt, args...) \
553do { \
554 if (0) \
555 ____trace_printk_check_format(fmt, ##args); \
556} while (0)
557
558/**
559 * trace_printk - printf formatting in the ftrace buffer
560 * @fmt: the printf format for printing
561 *
562 * Note: __trace_printk is an internal function for trace_printk and
563 * the @ip is passed in via the trace_printk macro.
564 *
565 * This function allows a kernel developer to debug fast path sections
566 * that printk is not appropriate for. By scattering in various
567 * printk like tracing in the code, a developer can quickly see
568 * where problems are occurring.
569 *
570 * This is intended as a debugging tool for the developer only.
571 * Please refrain from leaving trace_printks scattered around in
572 * your code. (Extra memory is used for special buffers that are
573 * allocated when trace_printk() is used)
574 *
575 * A little optization trick is done here. If there's only one
576 * argument, there's no need to scan the string for printf formats.
577 * The trace_puts() will suffice. But how can we take advantage of
578 * using trace_puts() when trace_printk() has only one argument?
579 * By stringifying the args and checking the size we can tell
580 * whether or not there are args. __stringify((__VA_ARGS__)) will
581 * turn into "()\0" with a size of 3 when there are no args, anything
582 * else will be bigger. All we need to do is define a string to this,
583 * and then take its size and compare to 3. If it's bigger, use
584 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just
585 * let gcc optimize the rest.
586 */
587
588#define trace_printk(fmt, ...) \
589do { \
590 char _______STR[] = __stringify((__VA_ARGS__)); \
591 if (sizeof(_______STR) > 3) \
592 do_trace_printk(fmt, ##__VA_ARGS__); \
593 else \
594 trace_puts(fmt); \
595} while (0)
596
597#define do_trace_printk(fmt, args...) \
598do { \
599 static const char *trace_printk_fmt \
600 __attribute__((section("__trace_printk_fmt"))) = \
601 __builtin_constant_p(fmt) ? fmt : NULL; \
602 \
603 __trace_printk_check_format(fmt, ##args); \
604 \
605 if (__builtin_constant_p(fmt)) \
606 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
607 else \
608 __trace_printk(_THIS_IP_, fmt, ##args); \
609} while (0)
610
611extern __printf(2, 3)
612int __trace_bprintk(unsigned long ip, const char *fmt, ...);
613
614extern __printf(2, 3)
615int __trace_printk(unsigned long ip, const char *fmt, ...);
616
617/**
618 * trace_puts - write a string into the ftrace buffer
619 * @str: the string to record
620 *
621 * Note: __trace_bputs is an internal function for trace_puts and
622 * the @ip is passed in via the trace_puts macro.
623 *
624 * This is similar to trace_printk() but is made for those really fast
625 * paths that a developer wants the least amount of "Heisenbug" affects,
626 * where the processing of the print format is still too much.
627 *
628 * This function allows a kernel developer to debug fast path sections
629 * that printk is not appropriate for. By scattering in various
630 * printk like tracing in the code, a developer can quickly see
631 * where problems are occurring.
632 *
633 * This is intended as a debugging tool for the developer only.
634 * Please refrain from leaving trace_puts scattered around in
635 * your code. (Extra memory is used for special buffers that are
636 * allocated when trace_puts() is used)
637 *
638 * Returns: 0 if nothing was written, positive # if string was.
639 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used)
640 */
641
642#define trace_puts(str) ({ \
643 static const char *trace_printk_fmt \
644 __attribute__((section("__trace_printk_fmt"))) = \
645 __builtin_constant_p(str) ? str : NULL; \
646 \
647 if (__builtin_constant_p(str)) \
648 __trace_bputs(_THIS_IP_, trace_printk_fmt); \
649 else \
650 __trace_puts(_THIS_IP_, str, strlen(str)); \
651})
652extern int __trace_bputs(unsigned long ip, const char *str);
653extern int __trace_puts(unsigned long ip, const char *str, int size);
654
655extern void trace_dump_stack(int skip);
656
657/*
658 * The double __builtin_constant_p is because gcc will give us an error
659 * if we try to allocate the static variable to fmt if it is not a
660 * constant. Even with the outer if statement.
661 */
662#define ftrace_vprintk(fmt, vargs) \
663do { \
664 if (__builtin_constant_p(fmt)) { \
665 static const char *trace_printk_fmt \
666 __attribute__((section("__trace_printk_fmt"))) = \
667 __builtin_constant_p(fmt) ? fmt : NULL; \
668 \
669 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
670 } else \
671 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
672} while (0)
673
674extern int
675__ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
676
677extern int
678__ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
679
680extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
681#else
682static inline void tracing_start(void) { }
683static inline void tracing_stop(void) { }
684static inline void trace_dump_stack(int skip) { }
685
686static inline void tracing_on(void) { }
687static inline void tracing_off(void) { }
688static inline int tracing_is_on(void) { return 0; }
689static inline void tracing_snapshot(void) { }
690static inline void tracing_snapshot_alloc(void) { }
691
692static inline __printf(1, 2)
693int trace_printk(const char *fmt, ...)
694{
695 return 0;
696}
697static inline int
698ftrace_vprintk(const char *fmt, va_list ap)
699{
700 return 0;
701}
702static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
703#endif /* CONFIG_TRACING */
704
705/*
706 * min()/max()/clamp() macros that also do
707 * strict type-checking.. See the
708 * "unnecessary" pointer comparison.
709 */
710#define min(x, y) ({ \
711 typeof(x) _min1 = (x); \
712 typeof(y) _min2 = (y); \
713 (void) (&_min1 == &_min2); \
714 _min1 < _min2 ? _min1 : _min2; })
715
716#define max(x, y) ({ \
717 typeof(x) _max1 = (x); \
718 typeof(y) _max2 = (y); \
719 (void) (&_max1 == &_max2); \
720 _max1 > _max2 ? _max1 : _max2; })
721
722#define min3(x, y, z) ({ \
723 typeof(x) _min1 = (x); \
724 typeof(y) _min2 = (y); \
725 typeof(z) _min3 = (z); \
726 (void) (&_min1 == &_min2); \
727 (void) (&_min1 == &_min3); \
728 _min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \
729 (_min2 < _min3 ? _min2 : _min3); })
730
731#define max3(x, y, z) ({ \
732 typeof(x) _max1 = (x); \
733 typeof(y) _max2 = (y); \
734 typeof(z) _max3 = (z); \
735 (void) (&_max1 == &_max2); \
736 (void) (&_max1 == &_max3); \
737 _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \
738 (_max2 > _max3 ? _max2 : _max3); })
739
740/**
741 * min_not_zero - return the minimum that is _not_ zero, unless both are zero
742 * @x: value1
743 * @y: value2
744 */
745#define min_not_zero(x, y) ({ \
746 typeof(x) __x = (x); \
747 typeof(y) __y = (y); \
748 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
749
750/**
751 * clamp - return a value clamped to a given range with strict typechecking
752 * @val: current value
753 * @min: minimum allowable value
754 * @max: maximum allowable value
755 *
756 * This macro does strict typechecking of min/max to make sure they are of the
757 * same type as val. See the unnecessary pointer comparisons.
758 */
759#define clamp(val, min, max) ({ \
760 typeof(val) __val = (val); \
761 typeof(min) __min = (min); \
762 typeof(max) __max = (max); \
763 (void) (&__val == &__min); \
764 (void) (&__val == &__max); \
765 __val = __val < __min ? __min: __val; \
766 __val > __max ? __max: __val; })
767
768/*
769 * ..and if you can't take the strict
770 * types, you can specify one yourself.
771 *
772 * Or not use min/max/clamp at all, of course.
773 */
774#define min_t(type, x, y) ({ \
775 type __min1 = (x); \
776 type __min2 = (y); \
777 __min1 < __min2 ? __min1: __min2; })
778
779#define max_t(type, x, y) ({ \
780 type __max1 = (x); \
781 type __max2 = (y); \
782 __max1 > __max2 ? __max1: __max2; })
783
784/**
785 * clamp_t - return a value clamped to a given range using a given type
786 * @type: the type of variable to use
787 * @val: current value
788 * @min: minimum allowable value
789 * @max: maximum allowable value
790 *
791 * This macro does no typechecking and uses temporary variables of type
792 * 'type' to make all the comparisons.
793 */
794#define clamp_t(type, val, min, max) ({ \
795 type __val = (val); \
796 type __min = (min); \
797 type __max = (max); \
798 __val = __val < __min ? __min: __val; \
799 __val > __max ? __max: __val; })
800
801/**
802 * clamp_val - return a value clamped to a given range using val's type
803 * @val: current value
804 * @min: minimum allowable value
805 * @max: maximum allowable value
806 *
807 * This macro does no typechecking and uses temporary variables of whatever
808 * type the input argument 'val' is. This is useful when val is an unsigned
809 * type and min and max are literals that will otherwise be assigned a signed
810 * integer type.
811 */
812#define clamp_val(val, min, max) ({ \
813 typeof(val) __val = (val); \
814 typeof(val) __min = (min); \
815 typeof(val) __max = (max); \
816 __val = __val < __min ? __min: __val; \
817 __val > __max ? __max: __val; })
818
819
820/*
821 * swap - swap value of @a and @b
822 */
823#define swap(a, b) \
824 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
825
826/**
827 * container_of - cast a member of a structure out to the containing structure
828 * @ptr: the pointer to the member.
829 * @type: the type of the container struct this is embedded in.
830 * @member: the name of the member within the struct.
831 *
832 */
833#define container_of(ptr, type, member) ({ \
834 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
835 (type *)( (char *)__mptr - offsetof(type,member) );})
836
837/* Trap pasters of __FUNCTION__ at compile-time */
838#define __FUNCTION__ (__func__)
839
840/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
841#ifdef CONFIG_FTRACE_MCOUNT_RECORD
842# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
843#endif
844
845/* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */
846#define VERIFY_OCTAL_PERMISSIONS(perms) \
847 (BUILD_BUG_ON_ZERO((perms) < 0) + \
848 BUILD_BUG_ON_ZERO((perms) > 0777) + \
849 /* User perms >= group perms >= other perms */ \
850 BUILD_BUG_ON_ZERO(((perms) >> 6) < (((perms) >> 3) & 7)) + \
851 BUILD_BUG_ON_ZERO((((perms) >> 3) & 7) < ((perms) & 7)) + \
852 (perms))
853#endif