blob: dc6a50f88ca7ba1deb18fe9a47bff3dad9af1977 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_KERNEL_H
2#define _LINUX_KERNEL_H
3
H. Peter Anvind8e5dde2012-02-06 16:36:48 -08004#include <linux/sysinfo.h>
5
Linus Torvalds1da177e2005-04-16 15:20:36 -07006/*
7 * 'kernel.h' contains some often-used function prototypes etc
8 */
Alexey Dobriyana79ff732010-04-13 11:21:46 +02009#define __ALIGN_KERNEL(x, a) __ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
10#define __ALIGN_KERNEL_MASK(x, mask) (((x) + (mask)) & ~(mask))
Linus Torvalds1da177e2005-04-16 15:20:36 -070011
12#ifdef __KERNEL__
13
14#include <stdarg.h>
15#include <linux/linkage.h>
16#include <linux/stddef.h>
17#include <linux/types.h>
18#include <linux/compiler.h>
19#include <linux/bitops.h>
David Howellsf0d1b0b2006-12-08 02:37:49 -080020#include <linux/log2.h>
Andrew Mortone0deaff2008-07-25 01:45:24 -070021#include <linux/typecheck.h>
Linus Torvalds968ab182010-11-15 13:37:37 -080022#include <linux/printk.h>
Jason Barone9d376f2009-02-05 11:51:38 -050023#include <linux/dynamic_debug.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <asm/byteorder.h>
25#include <asm/bug.h>
26
Alexey Dobriyan4be929b2010-05-24 14:33:03 -070027#define USHRT_MAX ((u16)(~0U))
28#define SHRT_MAX ((s16)(USHRT_MAX>>1))
29#define SHRT_MIN ((s16)(-SHRT_MAX - 1))
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#define INT_MAX ((int)(~0U>>1))
31#define INT_MIN (-INT_MAX - 1)
32#define UINT_MAX (~0U)
33#define LONG_MAX ((long)(~0UL>>1))
34#define LONG_MIN (-LONG_MAX - 1)
35#define ULONG_MAX (~0UL)
OGAWA Hirofumi111ebb62006-06-23 02:03:26 -070036#define LLONG_MAX ((long long)(~0ULL>>1))
37#define LLONG_MIN (-LLONG_MAX - 1)
38#define ULLONG_MAX (~0ULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
40#define STACK_MAGIC 0xdeadbeef
41
Alexey Dobriyana79ff732010-04-13 11:21:46 +020042#define ALIGN(x, a) __ALIGN_KERNEL((x), (a))
Alexey Dobriyan9f93ff52010-04-13 14:09:15 +020043#define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask))
Matthew Wilcoxa83308e2007-09-11 15:23:47 -070044#define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
Herbert Xuf10db622008-02-06 01:37:05 -080045#define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
Linus Torvalds2ea58142006-11-26 19:05:22 -080046
Rusty Russellc5e631c2007-05-06 14:51:05 -070047#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
48
Yinghai Lu9b3be9f2010-02-10 01:20:29 -080049/*
50 * This looks more complex than it should be. But we need to
51 * get the type for the ~ right in round_down (it needs to be
52 * as wide as the result!), and we want to evaluate the macro
53 * arguments just once each.
54 */
55#define __round_mask(x, y) ((__typeof__(x))((y)-1))
56#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
57#define round_down(x, y) ((x) & ~__round_mask(x, y))
58
Jan Beulich4552d5d2006-06-26 13:57:28 +020059#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
Steven Whitehouse930631e2006-09-25 23:32:40 -070060#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
Nicholas Bellinger36a26c62011-07-26 00:35:26 -070061#define DIV_ROUND_UP_ULL(ll,d) \
62 ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; })
63
64#if BITS_PER_LONG == 32
65# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
66#else
67# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
68#endif
James Morris074e61e2010-11-10 09:01:31 +110069
70/* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
Eric Parisb28efd52010-10-13 17:50:08 -040071#define roundup(x, y) ( \
72{ \
Tetsuo Handa6070bf32010-11-08 11:20:49 +090073 const typeof(y) __y = y; \
Eric Parisb28efd52010-10-13 17:50:08 -040074 (((x) + (__y - 1)) / __y) * __y; \
75} \
76)
Eric Paris686a0f32010-10-13 17:50:02 -040077#define rounddown(x, y) ( \
78{ \
79 typeof(x) __x = (x); \
80 __x - (__x % (y)); \
81} \
82)
Darrick J. Wong9fe06082009-01-06 14:40:51 -080083#define DIV_ROUND_CLOSEST(x, divisor)( \
84{ \
85 typeof(divisor) __divisor = divisor; \
86 (((x) + ((__divisor) / 2)) / (__divisor)); \
87} \
88)
Linus Torvalds1da177e2005-04-16 15:20:36 -070089
Eduard - Gabriel Munteanuca31e142008-07-05 12:14:23 +030090#define _RET_IP_ (unsigned long)__builtin_return_address(0)
91#define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
92
Bartlomiej Zolnierkiewicz90c699a2009-06-19 08:08:50 +020093#ifdef CONFIG_LBDAF
Jens Axboe2da96ac2007-10-12 12:40:38 +020094# include <asm/div64.h>
95# define sector_div(a, b) do_div(a, b)
96#else
97# define sector_div(n, b)( \
98{ \
99 int _res; \
100 _res = (n) % (b); \
101 (n) /= (b); \
102 _res; \
103} \
104)
105#endif
106
Andrew Morton218e1802007-05-10 03:15:18 -0700107/**
108 * upper_32_bits - return bits 32-63 of a number
109 * @n: the number we're accessing
110 *
111 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
112 * the "right shift count >= width of type" warning when that quantity is
113 * 32-bits.
114 */
115#define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
116
Joerg Roedel204b8852008-07-29 22:33:42 -0700117/**
118 * lower_32_bits - return bits 0-31 of a number
119 * @n: the number we're accessing
120 */
121#define lower_32_bits(n) ((u32)(n))
122
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123struct completion;
akpm@osdl.orgdf2e71f2006-01-09 20:51:37 -0800124struct pt_regs;
125struct user;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126
Uwe Kleine-König070cb062008-08-12 15:08:59 -0700127#ifdef CONFIG_PREEMPT_VOLUNTARY
128extern int _cond_resched(void);
129# define might_resched() _cond_resched()
130#else
131# define might_resched() do { } while (0)
132#endif
133
Frederic Weisbeckerd902db12011-06-08 19:31:56 +0200134#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
Simon Kagstromd8948372009-12-23 11:08:18 +0100135 void __might_sleep(const char *file, int line, int preempt_offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136/**
137 * might_sleep - annotation for functions that can sleep
138 *
139 * this macro will print a stack trace if it is executed in an atomic
140 * context (spinlock, irq-handler, ...).
141 *
142 * This is a useful debugging help to be able to catch problems early and not
Jim Cromiee20ec992006-11-30 04:46:13 +0100143 * be bitten later when the calling function happens to sleep when it is not
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 * supposed to.
145 */
Ingo Molnarf8cbd992005-06-25 14:57:39 -0700146# define might_sleep() \
Frederic Weisbeckere4aafea2009-07-16 15:44:29 +0200147 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
Ingo Molnarf8cbd992005-06-25 14:57:39 -0700148#else
Simon Kagstromd8948372009-12-23 11:08:18 +0100149 static inline void __might_sleep(const char *file, int line,
150 int preempt_offset) { }
Ingo Molnarf8cbd992005-06-25 14:57:39 -0700151# define might_sleep() do { might_resched(); } while (0)
152#endif
153
Hua Zhong368a5fa2006-06-23 02:05:42 -0700154#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
Ingo Molnarf8cbd992005-06-25 14:57:39 -0700155
Andrew Morton71a90482011-01-12 16:59:35 -0800156/*
157 * abs() handles unsigned and signed longs, ints, shorts and chars. For all
158 * input types abs() returns a signed long.
159 * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64()
160 * for those.
161 */
162#define abs(x) ({ \
163 long ret; \
164 if (sizeof(x) == sizeof(long)) { \
165 long __x = (x); \
166 ret = (__x < 0) ? -__x : __x; \
167 } else { \
168 int __x = (x); \
169 ret = (__x < 0) ? -__x : __x; \
170 } \
171 ret; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 })
173
Brian Behlendorf658716d2010-10-26 14:23:10 -0700174#define abs64(x) ({ \
175 s64 __x = (x); \
176 (__x < 0) ? -__x : __x; \
177 })
178
Nick Piggin3ee1afa2008-09-10 13:37:17 +0200179#ifdef CONFIG_PROVE_LOCKING
180void might_fault(void);
181#else
182static inline void might_fault(void)
183{
184 might_sleep();
185}
186#endif
187
Alan Sterne041c682006-03-27 01:16:30 -0800188extern struct atomic_notifier_head panic_notifier_list;
TAMUKI Shoichic7ff0d92010-08-10 18:03:28 -0700189extern long (*panic_blink)(int state);
Joe Perches9402c952012-01-12 17:17:17 -0800190__printf(1, 2)
Joe Perches4da47852012-01-12 17:17:13 -0800191void panic(const char *fmt, ...)
Joe Perchesff2d8b12012-01-12 17:17:21 -0800192 __noreturn __cold;
Andrew Mortondd287792006-03-23 03:00:57 -0800193extern void oops_enter(void);
194extern void oops_exit(void);
Anton Blanchard863a6042010-08-10 18:03:30 -0700195void print_oops_end_marker(void);
Andrew Mortondd287792006-03-23 03:00:57 -0800196extern int oops_may_print(void);
Joe Perches9402c952012-01-12 17:17:17 -0800197void do_exit(long error_code)
Joe Perchesff2d8b12012-01-12 17:17:21 -0800198 __noreturn;
Joe Perches9402c952012-01-12 17:17:17 -0800199void complete_and_exit(struct completion *, long)
Joe Perchesff2d8b12012-01-12 17:17:21 -0800200 __noreturn;
Alexey Dobriyan33ee3b22011-03-22 16:34:40 -0700201
202/* Internal, do not use. */
203int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
204int __must_check _kstrtol(const char *s, unsigned int base, long *res);
205
206int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
207int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
208static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
209{
210 /*
211 * We want to shortcut function call, but
212 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
213 */
214 if (sizeof(unsigned long) == sizeof(unsigned long long) &&
215 __alignof__(unsigned long) == __alignof__(unsigned long long))
216 return kstrtoull(s, base, (unsigned long long *)res);
217 else
218 return _kstrtoul(s, base, res);
219}
220
221static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
222{
223 /*
224 * We want to shortcut function call, but
225 * __builtin_types_compatible_p(long, long long) = 0.
226 */
227 if (sizeof(long) == sizeof(long long) &&
228 __alignof__(long) == __alignof__(long long))
229 return kstrtoll(s, base, (long long *)res);
230 else
231 return _kstrtol(s, base, res);
232}
233
234int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
235int __must_check kstrtoint(const char *s, unsigned int base, int *res);
236
237static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
238{
239 return kstrtoull(s, base, res);
240}
241
242static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
243{
244 return kstrtoll(s, base, res);
245}
246
247static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
248{
249 return kstrtouint(s, base, res);
250}
251
252static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
253{
254 return kstrtoint(s, base, res);
255}
256
257int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
258int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
259int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
260int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
261
Alexey Dobriyanc196e322011-05-24 17:13:31 -0700262int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
263int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
264int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
265int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
266int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
267int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
268int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
269int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
270int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
271int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
272
273static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
274{
275 return kstrtoull_from_user(s, count, base, res);
276}
277
278static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
279{
280 return kstrtoll_from_user(s, count, base, res);
281}
282
283static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
284{
285 return kstrtouint_from_user(s, count, base, res);
286}
287
288static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
289{
290 return kstrtoint_from_user(s, count, base, res);
291}
292
Joe Perches67d0a072011-10-31 17:13:10 -0700293/* Obsolete, do not use. Use kstrto<foo> instead */
294
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295extern unsigned long simple_strtoul(const char *,char **,unsigned int);
296extern long simple_strtol(const char *,char **,unsigned int);
297extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
298extern long long simple_strtoll(const char *,char **,unsigned int);
Alexey Dobriyan33ee3b22011-03-22 16:34:40 -0700299#define strict_strtoul kstrtoul
300#define strict_strtol kstrtol
301#define strict_strtoull kstrtoull
302#define strict_strtoll kstrtoll
303
Joe Perches67d0a072011-10-31 17:13:10 -0700304/* lib/printf utilities */
305
Joe Perchesb9075fa2011-10-31 17:11:33 -0700306extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
307extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
308extern __printf(3, 4)
309int snprintf(char *buf, size_t size, const char *fmt, ...);
310extern __printf(3, 0)
311int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
312extern __printf(3, 4)
313int scnprintf(char *buf, size_t size, const char *fmt, ...);
314extern __printf(3, 0)
315int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
316extern __printf(2, 3)
317char *kasprintf(gfp_t gfp, const char *fmt, ...);
Jeremy Fitzhardinge11443ec2007-04-30 15:09:56 -0700318extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319
320extern int sscanf(const char *, const char *, ...)
321 __attribute__ ((format (scanf, 2, 3)));
322extern int vsscanf(const char *, const char *, va_list)
323 __attribute__ ((format (scanf, 2, 0)));
324
325extern int get_option(char **str, int *pint);
326extern char *get_options(const char *str, int nints, int *ints);
Jeremy Fitzhardinged974ae32008-07-24 16:27:46 -0700327extern unsigned long long memparse(const char *ptr, char **retptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328
Trent Piepho5e376612006-05-15 09:44:06 -0700329extern int core_kernel_text(unsigned long addr);
Steven Rostedtcdbe61b2011-05-05 21:14:55 -0400330extern int core_kernel_data(unsigned long addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331extern int __kernel_text_address(unsigned long addr);
332extern int kernel_text_address(unsigned long addr);
Arjan van de Venab7476c2008-08-15 15:29:38 -0700333extern int func_ptr_is_kernel_text(void *ptr);
Arjan van de Venab7476c2008-08-15 15:29:38 -0700334
Eric W. Biederman04a2e6a2007-02-12 00:52:56 -0800335struct pid;
336extern struct pid *session_of_pgrp(struct pid *pgrp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338unsigned long int_sqrt(unsigned long);
339
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340extern void bust_spinlocks(int yes);
Kirill Korotaeve3e8a752007-02-10 01:46:19 -0800341extern void wake_up_klogd(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
Adrian Bunkaa727102006-04-10 22:53:59 -0700343extern int panic_timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344extern int panic_on_oops;
Don Zickus8da5add2006-09-26 10:52:27 +0200345extern int panic_on_unrecovered_nmi;
Kurt Garloff5211a242009-06-24 14:32:11 -0700346extern int panic_on_io_nmi;
Mitsuo Hayasaka55af7792011-11-29 15:08:36 +0900347extern int sysctl_panic_on_stackoverflow;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348extern const char *print_tainted(void);
Andi Kleen25ddbb12008-10-15 22:01:41 -0700349extern void add_taint(unsigned flag);
350extern int test_taint(unsigned flag);
351extern unsigned long get_taint(void);
David Howellsb920de12008-02-08 04:19:31 -0800352extern int root_mountflags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353
Tejun Heo2ce802f2011-01-20 12:06:35 +0100354extern bool early_boot_irqs_disabled;
355
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356/* Values used for system_state */
357extern enum system_states {
358 SYSTEM_BOOTING,
359 SYSTEM_RUNNING,
360 SYSTEM_HALT,
361 SYSTEM_POWER_OFF,
362 SYSTEM_RESTART,
Alexey Starikovskiy729b4d42005-12-01 04:29:00 -0500363 SYSTEM_SUSPEND_DISK,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364} system_state;
365
Andi Kleen25ddbb12008-10-15 22:01:41 -0700366#define TAINT_PROPRIETARY_MODULE 0
367#define TAINT_FORCED_MODULE 1
368#define TAINT_UNSAFE_SMP 2
369#define TAINT_FORCED_RMMOD 3
370#define TAINT_MACHINE_CHECK 4
371#define TAINT_BAD_PAGE 5
372#define TAINT_USER 6
373#define TAINT_DIE 7
374#define TAINT_OVERRIDDEN_ACPI_TABLE 8
375#define TAINT_WARN 9
Linus Torvalds26e9a392008-10-17 09:50:12 -0700376#define TAINT_CRAP 10
Ben Hutchings92946bc2010-04-03 19:36:42 +0100377#define TAINT_FIRMWARE_WORKAROUND 11
Ben Hutchings2449b8b2011-10-24 15:12:28 +0200378#define TAINT_OOT_MODULE 12
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379
Harvey Harrison3fc95772008-05-14 16:05:49 -0700380extern const char hex_asc[];
381#define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
382#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
383
Andy Shevchenko55036ba2011-10-31 17:12:41 -0700384static inline char *hex_byte_pack(char *buf, u8 byte)
Harvey Harrison3fc95772008-05-14 16:05:49 -0700385{
386 *buf++ = hex_asc_hi(byte);
387 *buf++ = hex_asc_lo(byte);
388 return buf;
389}
Randy Dunlap99eaf3c2007-05-10 22:22:39 -0700390
Andy Shevchenko55036ba2011-10-31 17:12:41 -0700391static inline char * __deprecated pack_hex_byte(char *buf, u8 byte)
392{
393 return hex_byte_pack(buf, byte);
394}
395
Andy Shevchenko90378882010-05-24 14:33:23 -0700396extern int hex_to_bin(char ch);
Mimi Zoharb7804982011-09-20 11:23:49 -0400397extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
Andy Shevchenko90378882010-05-24 14:33:23 -0700398
Joe Perches8a64f332009-12-14 18:00:25 -0800399/*
Ingo Molnar526211b2009-03-05 10:28:45 +0100400 * General tracing related utility functions - trace_printk(),
Steven Rostedt2002c252009-03-05 10:35:56 -0500401 * tracing_on/tracing_off and tracing_start()/tracing_stop
402 *
403 * Use tracing_on/tracing_off when you want to quickly turn on or off
404 * tracing. It simply enables or disables the recording of the trace events.
GeunSik Lim156f5a72009-06-02 15:01:37 +0900405 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
Steven Rostedt2002c252009-03-05 10:35:56 -0500406 * file, which gives a means for the kernel and userspace to interact.
407 * Place a tracing_off() in the kernel where you want tracing to end.
408 * From user space, examine the trace, and then echo 1 > tracing_on
409 * to continue tracing.
410 *
411 * tracing_stop/tracing_start has slightly more overhead. It is used
412 * by things like suspend to ram where disabling the recording of the
413 * trace is not enough, but tracing must actually stop because things
414 * like calling smp_processor_id() may crash the system.
415 *
416 * Most likely, you want to use tracing_on/tracing_off.
Ingo Molnar526211b2009-03-05 10:28:45 +0100417 */
Steven Rostedt2002c252009-03-05 10:35:56 -0500418#ifdef CONFIG_RING_BUFFER
419void tracing_on(void);
420void tracing_off(void);
421/* trace_off_permanent stops recording with no way to bring it back */
422void tracing_off_permanent(void);
423int tracing_is_on(void);
424#else
425static inline void tracing_on(void) { }
426static inline void tracing_off(void) { }
427static inline void tracing_off_permanent(void) { }
428static inline int tracing_is_on(void) { return 0; }
429#endif
Frederic Weisbeckercecbca92010-04-18 19:08:41 +0200430
431enum ftrace_dump_mode {
432 DUMP_NONE,
433 DUMP_ALL,
434 DUMP_ORIG,
435};
436
Ingo Molnar526211b2009-03-05 10:28:45 +0100437#ifdef CONFIG_TRACING
438extern void tracing_start(void);
439extern void tracing_stop(void);
440extern void ftrace_off_permanent(void);
441
Joe Perchesb9075fa2011-10-31 17:11:33 -0700442static inline __printf(1, 2)
443void ____trace_printk_check_format(const char *fmt, ...)
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100444{
445}
446#define __trace_printk_check_format(fmt, args...) \
447do { \
448 if (0) \
449 ____trace_printk_check_format(fmt, ##args); \
450} while (0)
451
Ingo Molnar526211b2009-03-05 10:28:45 +0100452/**
453 * trace_printk - printf formatting in the ftrace buffer
454 * @fmt: the printf format for printing
455 *
456 * Note: __trace_printk is an internal function for trace_printk and
457 * the @ip is passed in via the trace_printk macro.
458 *
459 * This function allows a kernel developer to debug fast path sections
460 * that printk is not appropriate for. By scattering in various
461 * printk like tracing in the code, a developer can quickly see
462 * where problems are occurring.
463 *
464 * This is intended as a debugging tool for the developer only.
465 * Please refrain from leaving trace_printks scattered around in
466 * your code.
467 */
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100468
469#define trace_printk(fmt, args...) \
470do { \
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100471 __trace_printk_check_format(fmt, ##args); \
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100472 if (__builtin_constant_p(fmt)) { \
473 static const char *trace_printk_fmt \
474 __attribute__((section("__trace_printk_fmt"))) = \
475 __builtin_constant_p(fmt) ? fmt : NULL; \
476 \
477 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
478 } else \
479 __trace_printk(_THIS_IP_, fmt, ##args); \
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100480} while (0)
481
Joe Perchesb9075fa2011-10-31 17:11:33 -0700482extern __printf(2, 3)
483int __trace_bprintk(unsigned long ip, const char *fmt, ...);
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100484
Joe Perchesb9075fa2011-10-31 17:11:33 -0700485extern __printf(2, 3)
486int __trace_printk(unsigned long ip, const char *fmt, ...);
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100487
Steven Rostedt03889382009-12-11 09:48:22 -0500488extern void trace_dump_stack(void);
489
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100490/*
491 * The double __builtin_constant_p is because gcc will give us an error
492 * if we try to allocate the static variable to fmt if it is not a
493 * constant. Even with the outer if statement.
494 */
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100495#define ftrace_vprintk(fmt, vargs) \
496do { \
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100497 if (__builtin_constant_p(fmt)) { \
498 static const char *trace_printk_fmt \
499 __attribute__((section("__trace_printk_fmt"))) = \
500 __builtin_constant_p(fmt) ? fmt : NULL; \
Ingo Molnar7bffc232009-03-09 10:11:36 +0100501 \
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100502 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
503 } else \
504 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100505} while (0)
506
Ingo Molnar526211b2009-03-05 10:28:45 +0100507extern int
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100508__ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
509
510extern int
Ingo Molnar526211b2009-03-05 10:28:45 +0100511__ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100512
Frederic Weisbeckercecbca92010-04-18 19:08:41 +0200513extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
Ingo Molnar526211b2009-03-05 10:28:45 +0100514#else
Joe Perchesb9075fa2011-10-31 17:11:33 -0700515static inline __printf(1, 2)
516int trace_printk(const char *fmt, ...);
Ingo Molnar526211b2009-03-05 10:28:45 +0100517
518static inline void tracing_start(void) { }
519static inline void tracing_stop(void) { }
520static inline void ftrace_off_permanent(void) { }
Steven Rostedte36c5452009-12-14 15:58:33 -0500521static inline void trace_dump_stack(void) { }
Ingo Molnar526211b2009-03-05 10:28:45 +0100522static inline int
523trace_printk(const char *fmt, ...)
524{
525 return 0;
526}
527static inline int
528ftrace_vprintk(const char *fmt, va_list ap)
529{
530 return 0;
531}
Frederic Weisbeckercecbca92010-04-18 19:08:41 +0200532static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100533#endif /* CONFIG_TRACING */
Ingo Molnar526211b2009-03-05 10:28:45 +0100534
535/*
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700536 * min()/max()/clamp() macros that also do
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 * strict type-checking.. See the
538 * "unnecessary" pointer comparison.
539 */
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700540#define min(x, y) ({ \
541 typeof(x) _min1 = (x); \
542 typeof(y) _min2 = (y); \
543 (void) (&_min1 == &_min2); \
544 _min1 < _min2 ? _min1 : _min2; })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700546#define max(x, y) ({ \
547 typeof(x) _max1 = (x); \
548 typeof(y) _max2 = (y); \
549 (void) (&_max1 == &_max2); \
550 _max1 > _max2 ? _max1 : _max2; })
551
Hagen Paul Pfeiferf27c85c2010-10-26 14:22:21 -0700552#define min3(x, y, z) ({ \
553 typeof(x) _min1 = (x); \
554 typeof(y) _min2 = (y); \
555 typeof(z) _min3 = (z); \
556 (void) (&_min1 == &_min2); \
557 (void) (&_min1 == &_min3); \
558 _min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \
559 (_min2 < _min3 ? _min2 : _min3); })
560
561#define max3(x, y, z) ({ \
562 typeof(x) _max1 = (x); \
563 typeof(y) _max2 = (y); \
564 typeof(z) _max3 = (z); \
565 (void) (&_max1 == &_max2); \
566 (void) (&_max1 == &_max3); \
567 _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \
568 (_max2 > _max3 ? _max2 : _max3); })
569
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700570/**
Martin K. Petersenc8bf1332010-09-10 20:07:38 +0200571 * min_not_zero - return the minimum that is _not_ zero, unless both are zero
572 * @x: value1
573 * @y: value2
574 */
575#define min_not_zero(x, y) ({ \
576 typeof(x) __x = (x); \
577 typeof(y) __y = (y); \
578 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
579
580/**
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700581 * clamp - return a value clamped to a given range with strict typechecking
582 * @val: current value
583 * @min: minimum allowable value
584 * @max: maximum allowable value
585 *
586 * This macro does strict typechecking of min/max to make sure they are of the
587 * same type as val. See the unnecessary pointer comparisons.
588 */
589#define clamp(val, min, max) ({ \
590 typeof(val) __val = (val); \
591 typeof(min) __min = (min); \
592 typeof(max) __max = (max); \
593 (void) (&__val == &__min); \
594 (void) (&__val == &__max); \
595 __val = __val < __min ? __min: __val; \
596 __val > __max ? __max: __val; })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597
598/*
599 * ..and if you can't take the strict
600 * types, you can specify one yourself.
601 *
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700602 * Or not use min/max/clamp at all, of course.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 */
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700604#define min_t(type, x, y) ({ \
605 type __min1 = (x); \
606 type __min2 = (y); \
607 __min1 < __min2 ? __min1: __min2; })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700609#define max_t(type, x, y) ({ \
610 type __max1 = (x); \
611 type __max2 = (y); \
612 __max1 > __max2 ? __max1: __max2; })
613
614/**
615 * clamp_t - return a value clamped to a given range using a given type
616 * @type: the type of variable to use
617 * @val: current value
618 * @min: minimum allowable value
619 * @max: maximum allowable value
620 *
621 * This macro does no typechecking and uses temporary variables of type
622 * 'type' to make all the comparisons.
623 */
624#define clamp_t(type, val, min, max) ({ \
625 type __val = (val); \
626 type __min = (min); \
627 type __max = (max); \
628 __val = __val < __min ? __min: __val; \
629 __val > __max ? __max: __val; })
630
631/**
632 * clamp_val - return a value clamped to a given range using val's type
633 * @val: current value
634 * @min: minimum allowable value
635 * @max: maximum allowable value
636 *
637 * This macro does no typechecking and uses temporary variables of whatever
638 * type the input argument 'val' is. This is useful when val is an unsigned
639 * type and min and max are literals that will otherwise be assigned a signed
640 * integer type.
641 */
642#define clamp_val(val, min, max) ({ \
643 typeof(val) __val = (val); \
644 typeof(val) __min = (min); \
645 typeof(val) __max = (max); \
646 __val = __val < __min ? __min: __val; \
647 __val > __max ? __max: __val; })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648
Wu Fengguang91f68b72009-01-07 18:09:12 -0800649
650/*
651 * swap - swap value of @a and @b
652 */
Peter Zijlstraac7b9002009-02-04 15:11:59 -0800653#define swap(a, b) \
654 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
Wu Fengguang91f68b72009-01-07 18:09:12 -0800655
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656/**
657 * container_of - cast a member of a structure out to the containing structure
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658 * @ptr: the pointer to the member.
659 * @type: the type of the container struct this is embedded in.
660 * @member: the name of the member within the struct.
661 *
662 */
663#define container_of(ptr, type, member) ({ \
Daniel Walker78db2ad2007-05-12 16:28:35 -0700664 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
665 (type *)( (char *)__mptr - offsetof(type,member) );})
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666
KOSAKI Motohiro903c0c72011-05-24 17:13:16 -0700667#ifdef __CHECKER__
668#define BUILD_BUG_ON_NOT_POWER_OF_2(n)
Dr. David Alan Gilbertca395992011-06-15 15:08:27 -0700669#define BUILD_BUG_ON_ZERO(e) (0)
670#define BUILD_BUG_ON_NULL(e) ((void*)0)
KOSAKI Motohiro903c0c72011-05-24 17:13:16 -0700671#define BUILD_BUG_ON(condition)
David Daney1399ff82012-01-10 15:07:25 -0800672#define BUILD_BUG() (0)
KOSAKI Motohiro903c0c72011-05-24 17:13:16 -0700673#else /* __CHECKER__ */
674
Roland Dreiercc8ef6e2010-01-15 17:01:22 -0800675/* Force a compilation error if a constant expression is not a power of 2 */
676#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \
677 BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
678
Jan Beulich4552d5d2006-06-26 13:57:28 +0200679/* Force a compilation error if condition is true, but also produce a
680 result (of value 0 and type size_t), so the expression can be used
681 e.g. in a structure initializer (or where-ever else comma expressions
682 aren't permitted). */
Jan Beulich8c87df42009-09-22 16:43:52 -0700683#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
684#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
Jan Beulich4552d5d2006-06-26 13:57:28 +0200685
Rusty Russell7ef88ad2011-01-24 14:45:10 -0600686/**
687 * BUILD_BUG_ON - break compile if a condition is true.
Randy Dunlapffbbf2d2011-01-31 09:29:14 -0800688 * @condition: the condition which the compiler should know is false.
Rusty Russell7ef88ad2011-01-24 14:45:10 -0600689 *
690 * If you have some code which relies on certain constants being equal, or
691 * other compile-time-evaluated condition, you should use BUILD_BUG_ON to
692 * detect if someone changes it.
693 *
694 * The implementation uses gcc's reluctance to create a negative array, but
695 * gcc (as of 4.4) only emits that error for obvious cases (eg. not arguments
696 * to inline functions). So as a fallback we use the optimizer; if it can't
697 * prove the condition is false, it will cause a link error on the undefined
698 * "__build_bug_on_failed". This error message can be harder to track down
699 * though, hence the two different methods.
700 */
701#ifndef __OPTIMIZE__
702#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
703#else
704extern int __build_bug_on_failed;
705#define BUILD_BUG_ON(condition) \
706 do { \
707 ((void)sizeof(char[1 - 2*!!(condition)])); \
708 if (condition) __build_bug_on_failed = 1; \
709 } while(0)
710#endif
David Daney1399ff82012-01-10 15:07:25 -0800711
712/**
713 * BUILD_BUG - break compile if used.
714 *
715 * If you have some code that you expect the compiler to eliminate at
716 * build time, you should use BUILD_BUG to detect if it is
717 * unexpectedly used.
718 */
719#define BUILD_BUG() \
720 do { \
721 extern void __build_bug_failed(void) \
722 __linktime_error("BUILD_BUG failed"); \
723 __build_bug_failed(); \
724 } while (0)
725
KOSAKI Motohiro903c0c72011-05-24 17:13:16 -0700726#endif /* __CHECKER__ */
Rusty Russell7ef88ad2011-01-24 14:45:10 -0600727
Arnaud Lacombeb9d4f422011-07-25 17:13:03 -0700728/* Trap pasters of __FUNCTION__ at compile-time */
729#define __FUNCTION__ (__func__)
730
731/* This helps us to avoid #ifdef CONFIG_NUMA */
732#ifdef CONFIG_NUMA
733#define NUMA_BUILD 1
734#else
735#define NUMA_BUILD 0
736#endif
737
738/* This helps us avoid #ifdef CONFIG_COMPACTION */
739#ifdef CONFIG_COMPACTION
740#define COMPACTION_BUILD 1
741#else
742#define COMPACTION_BUILD 0
743#endif
744
745/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
746#ifdef CONFIG_FTRACE_MCOUNT_RECORD
747# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
748#endif
WANG Cong9d00f922011-07-25 17:13:02 -0700749
WANG Cong9d00f922011-07-25 17:13:02 -0700750extern int do_sysinfo(struct sysinfo *info);
751
752#endif /* __KERNEL__ */
753
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754#endif