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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 Mortone0deaff42008-07-25 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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
Alexey Dobriyan4be929b2010-05-24 14:33:03 -070026#define USHRT_MAX ((u16)(~0U))
27#define SHRT_MAX ((s16)(USHRT_MAX>>1))
28#define SHRT_MIN ((s16)(-SHRT_MAX - 1))
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#define INT_MAX ((int)(~0U>>1))
30#define INT_MIN (-INT_MAX - 1)
31#define UINT_MAX (~0U)
32#define LONG_MAX ((long)(~0UL>>1))
33#define LONG_MIN (-LONG_MAX - 1)
34#define ULONG_MAX (~0UL)
OGAWA Hirofumi111ebb62006-06-23 02:03:26 -070035#define LLONG_MAX ((long long)(~0ULL>>1))
36#define LLONG_MIN (-LLONG_MAX - 1)
37#define ULLONG_MAX (~0ULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
39#define STACK_MAGIC 0xdeadbeef
40
David S. Miller44696902012-05-23 20:12:50 -070041#define REPEAT_BYTE(x) ((~0ul / 0xff) * (x))
42
Alexey Dobriyana79ff732010-04-13 11:21:46 +020043#define ALIGN(x, a) __ALIGN_KERNEL((x), (a))
Alexey Dobriyan9f93ff52010-04-13 14:09:15 +020044#define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask))
Matthew Wilcoxa83308e2007-09-11 15:23:47 -070045#define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
Herbert Xuf10db622008-02-06 01:37:05 -080046#define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
Linus Torvalds2ea58142006-11-26 19:05:22 -080047
Rusty Russellc5e631cf2007-05-06 14:51:05 -070048#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
49
Yinghai Lu9b3be9f2010-02-10 01:20:29 -080050/*
51 * This looks more complex than it should be. But we need to
52 * get the type for the ~ right in round_down (it needs to be
53 * as wide as the result!), and we want to evaluate the macro
54 * arguments just once each.
55 */
56#define __round_mask(x, y) ((__typeof__(x))((y)-1))
57#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
58#define round_down(x, y) ((x) & ~__round_mask(x, y))
59
Jan Beulich4552d5d2006-06-26 13:57:28 +020060#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
Steven Whitehouse930631e2006-09-25 23:32:40 -070061#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
Nicholas Bellinger36a26c62011-07-26 00:35:26 -070062#define DIV_ROUND_UP_ULL(ll,d) \
63 ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; })
64
65#if BITS_PER_LONG == 32
66# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
67#else
68# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
69#endif
James Morris074e61e2010-11-10 09:01:31 +110070
71/* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
Eric Parisb28efd52010-10-13 17:50:08 -040072#define roundup(x, y) ( \
73{ \
Tetsuo Handa6070bf32010-11-08 11:20:49 +090074 const typeof(y) __y = y; \
Eric Parisb28efd52010-10-13 17:50:08 -040075 (((x) + (__y - 1)) / __y) * __y; \
76} \
77)
Eric Paris686a0f32010-10-13 17:50:02 -040078#define rounddown(x, y) ( \
79{ \
80 typeof(x) __x = (x); \
81 __x - (__x % (y)); \
82} \
83)
Darrick J. Wong9fe06082009-01-06 14:40:51 -080084#define DIV_ROUND_CLOSEST(x, divisor)( \
85{ \
86 typeof(divisor) __divisor = divisor; \
87 (((x) + ((__divisor) / 2)) / (__divisor)); \
88} \
89)
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
Salman Qazi9993bc632012-03-09 16:41:01 -080091/*
92 * Multiplies an integer by a fraction, while avoiding unnecessary
93 * overflow or loss of precision.
94 */
95#define mult_frac(x, numer, denom)( \
96{ \
97 typeof(x) quot = (x) / (denom); \
98 typeof(x) rem = (x) % (denom); \
99 (quot * (numer)) + ((rem * (numer)) / (denom)); \
100} \
101)
102
103
Eduard - Gabriel Munteanuca31e142008-07-05 12:14:23 +0300104#define _RET_IP_ (unsigned long)__builtin_return_address(0)
105#define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
106
Bartlomiej Zolnierkiewicz90c699a2009-06-19 08:08:50 +0200107#ifdef CONFIG_LBDAF
Jens Axboe2da96ac2007-10-12 12:40:38 +0200108# include <asm/div64.h>
109# define sector_div(a, b) do_div(a, b)
110#else
111# define sector_div(n, b)( \
112{ \
113 int _res; \
114 _res = (n) % (b); \
115 (n) /= (b); \
116 _res; \
117} \
118)
119#endif
120
Andrew Morton218e1802007-05-10 03:15:18 -0700121/**
122 * upper_32_bits - return bits 32-63 of a number
123 * @n: the number we're accessing
124 *
125 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
126 * the "right shift count >= width of type" warning when that quantity is
127 * 32-bits.
128 */
129#define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
130
Joerg Roedel204b8852008-07-29 22:33:42 -0700131/**
132 * lower_32_bits - return bits 0-31 of a number
133 * @n: the number we're accessing
134 */
135#define lower_32_bits(n) ((u32)(n))
136
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137struct completion;
akpm@osdl.orgdf2e71f2006-01-09 20:51:37 -0800138struct pt_regs;
139struct user;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140
Uwe Kleine-König070cb062008-08-12 15:08:59 -0700141#ifdef CONFIG_PREEMPT_VOLUNTARY
142extern int _cond_resched(void);
143# define might_resched() _cond_resched()
144#else
145# define might_resched() do { } while (0)
146#endif
147
Frederic Weisbeckerd902db12011-06-08 19:31:56 +0200148#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
Simon Kagstromd8948372009-12-23 11:08:18 +0100149 void __might_sleep(const char *file, int line, int preempt_offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150/**
151 * might_sleep - annotation for functions that can sleep
152 *
153 * this macro will print a stack trace if it is executed in an atomic
154 * context (spinlock, irq-handler, ...).
155 *
156 * This is a useful debugging help to be able to catch problems early and not
Jim Cromiee20ec992006-11-30 04:46:13 +0100157 * be bitten later when the calling function happens to sleep when it is not
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 * supposed to.
159 */
Ingo Molnarf8cbd992005-06-25 14:57:39 -0700160# define might_sleep() \
Frederic Weisbeckere4aafea2009-07-16 15:44:29 +0200161 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
Ingo Molnarf8cbd992005-06-25 14:57:39 -0700162#else
Simon Kagstromd8948372009-12-23 11:08:18 +0100163 static inline void __might_sleep(const char *file, int line,
164 int preempt_offset) { }
Ingo Molnarf8cbd992005-06-25 14:57:39 -0700165# define might_sleep() do { might_resched(); } while (0)
166#endif
167
Hua Zhong368a5fa2006-06-23 02:05:42 -0700168#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
Ingo Molnarf8cbd992005-06-25 14:57:39 -0700169
Andrew Morton71a90482011-01-12 16:59:35 -0800170/*
171 * abs() handles unsigned and signed longs, ints, shorts and chars. For all
172 * input types abs() returns a signed long.
173 * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64()
174 * for those.
175 */
176#define abs(x) ({ \
177 long ret; \
178 if (sizeof(x) == sizeof(long)) { \
179 long __x = (x); \
180 ret = (__x < 0) ? -__x : __x; \
181 } else { \
182 int __x = (x); \
183 ret = (__x < 0) ? -__x : __x; \
184 } \
185 ret; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 })
187
Brian Behlendorf658716d2010-10-26 14:23:10 -0700188#define abs64(x) ({ \
189 s64 __x = (x); \
190 (__x < 0) ? -__x : __x; \
191 })
192
Nick Piggin3ee1afa2008-09-10 13:37:17 +0200193#ifdef CONFIG_PROVE_LOCKING
194void might_fault(void);
195#else
196static inline void might_fault(void)
197{
198 might_sleep();
199}
200#endif
201
Alan Sterne041c682006-03-27 01:16:30 -0800202extern struct atomic_notifier_head panic_notifier_list;
TAMUKI Shoichic7ff0d92010-08-10 18:03:28 -0700203extern long (*panic_blink)(int state);
Joe Perches9402c952012-01-12 17:17:17 -0800204__printf(1, 2)
Joe Perches4da47852012-01-12 17:17:13 -0800205void panic(const char *fmt, ...)
Joe Perchesff2d8b12012-01-12 17:17:21 -0800206 __noreturn __cold;
Andrew Mortondd287792006-03-23 03:00:57 -0800207extern void oops_enter(void);
208extern void oops_exit(void);
Anton Blanchard863a6042010-08-10 18:03:30 -0700209void print_oops_end_marker(void);
Andrew Mortondd287792006-03-23 03:00:57 -0800210extern int oops_may_print(void);
Joe Perches9402c952012-01-12 17:17:17 -0800211void do_exit(long error_code)
Joe Perchesff2d8b12012-01-12 17:17:21 -0800212 __noreturn;
Joe Perches9402c952012-01-12 17:17:17 -0800213void complete_and_exit(struct completion *, long)
Joe Perchesff2d8b12012-01-12 17:17:21 -0800214 __noreturn;
Alexey Dobriyan33ee3b22011-03-22 16:34:40 -0700215
216/* Internal, do not use. */
217int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
218int __must_check _kstrtol(const char *s, unsigned int base, long *res);
219
220int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
221int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
222static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
223{
224 /*
225 * We want to shortcut function call, but
226 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
227 */
228 if (sizeof(unsigned long) == sizeof(unsigned long long) &&
229 __alignof__(unsigned long) == __alignof__(unsigned long long))
230 return kstrtoull(s, base, (unsigned long long *)res);
231 else
232 return _kstrtoul(s, base, res);
233}
234
235static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
236{
237 /*
238 * We want to shortcut function call, but
239 * __builtin_types_compatible_p(long, long long) = 0.
240 */
241 if (sizeof(long) == sizeof(long long) &&
242 __alignof__(long) == __alignof__(long long))
243 return kstrtoll(s, base, (long long *)res);
244 else
245 return _kstrtol(s, base, res);
246}
247
248int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
249int __must_check kstrtoint(const char *s, unsigned int base, int *res);
250
251static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
252{
253 return kstrtoull(s, base, res);
254}
255
256static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
257{
258 return kstrtoll(s, base, res);
259}
260
261static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
262{
263 return kstrtouint(s, base, res);
264}
265
266static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
267{
268 return kstrtoint(s, base, res);
269}
270
271int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
272int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
273int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
274int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
275
Alexey Dobriyanc196e322011-05-24 17:13:31 -0700276int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
277int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
278int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
279int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
280int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
281int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
282int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
283int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
284int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
285int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
286
287static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
288{
289 return kstrtoull_from_user(s, count, base, res);
290}
291
292static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
293{
294 return kstrtoll_from_user(s, count, base, res);
295}
296
297static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
298{
299 return kstrtouint_from_user(s, count, base, res);
300}
301
302static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
303{
304 return kstrtoint_from_user(s, count, base, res);
305}
306
Joe Perches67d0a072011-10-31 17:13:10 -0700307/* Obsolete, do not use. Use kstrto<foo> instead */
308
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309extern unsigned long simple_strtoul(const char *,char **,unsigned int);
310extern long simple_strtol(const char *,char **,unsigned int);
311extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
312extern long long simple_strtoll(const char *,char **,unsigned int);
Alexey Dobriyan33ee3b22011-03-22 16:34:40 -0700313#define strict_strtoul kstrtoul
314#define strict_strtol kstrtol
315#define strict_strtoull kstrtoull
316#define strict_strtoll kstrtoll
317
KAMEZAWA Hiroyuki1ac101a2012-03-23 15:02:54 -0700318extern int num_to_str(char *buf, int size, unsigned long long num);
319
Joe Perches67d0a072011-10-31 17:13:10 -0700320/* lib/printf utilities */
321
Joe Perchesb9075fa2011-10-31 17:11:33 -0700322extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
323extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
324extern __printf(3, 4)
325int snprintf(char *buf, size_t size, const char *fmt, ...);
326extern __printf(3, 0)
327int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
328extern __printf(3, 4)
329int scnprintf(char *buf, size_t size, const char *fmt, ...);
330extern __printf(3, 0)
331int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
332extern __printf(2, 3)
333char *kasprintf(gfp_t gfp, const char *fmt, ...);
Jeremy Fitzhardinge11443ec2007-04-30 15:09:56 -0700334extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335
Joe Perches6061d942012-03-23 15:02:16 -0700336extern __scanf(2, 3)
337int sscanf(const char *, const char *, ...);
338extern __scanf(2, 0)
339int vsscanf(const char *, const char *, va_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340
341extern int get_option(char **str, int *pint);
342extern char *get_options(const char *str, int nints, int *ints);
Jeremy Fitzhardinged974ae32008-07-24 16:27:46 -0700343extern unsigned long long memparse(const char *ptr, char **retptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344
Trent Piepho5e376612006-05-15 09:44:06 -0700345extern int core_kernel_text(unsigned long addr);
Steven Rostedtcdbe61b2011-05-05 21:14:55 -0400346extern int core_kernel_data(unsigned long addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347extern int __kernel_text_address(unsigned long addr);
348extern int kernel_text_address(unsigned long addr);
Arjan van de Venab7476c2008-08-15 15:29:38 -0700349extern int func_ptr_is_kernel_text(void *ptr);
Arjan van de Venab7476c2008-08-15 15:29:38 -0700350
Eric W. Biederman04a2e6a2007-02-12 00:52:56 -0800351struct pid;
352extern struct pid *session_of_pgrp(struct pid *pgrp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354unsigned long int_sqrt(unsigned long);
355
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356extern void bust_spinlocks(int yes);
Kirill Korotaeve3e8a752007-02-10 01:46:19 -0800357extern void wake_up_klogd(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
Adrian Bunkaa727102006-04-10 22:53:59 -0700359extern int panic_timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360extern int panic_on_oops;
Don Zickus8da5add2006-09-26 10:52:27 +0200361extern int panic_on_unrecovered_nmi;
Kurt Garloff5211a242009-06-24 14:32:11 -0700362extern int panic_on_io_nmi;
Mitsuo Hayasaka55af7792011-11-29 15:08:36 +0900363extern int sysctl_panic_on_stackoverflow;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364extern const char *print_tainted(void);
Andi Kleen25ddbb12008-10-15 22:01:41 -0700365extern void add_taint(unsigned flag);
366extern int test_taint(unsigned flag);
367extern unsigned long get_taint(void);
David Howellsb920de12008-02-08 04:19:31 -0800368extern int root_mountflags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369
Tejun Heo2ce802f2011-01-20 12:06:35 +0100370extern bool early_boot_irqs_disabled;
371
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372/* Values used for system_state */
373extern enum system_states {
374 SYSTEM_BOOTING,
375 SYSTEM_RUNNING,
376 SYSTEM_HALT,
377 SYSTEM_POWER_OFF,
378 SYSTEM_RESTART,
Alexey Starikovskiy729b4d42005-12-01 04:29:00 -0500379 SYSTEM_SUSPEND_DISK,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380} system_state;
381
Andi Kleen25ddbb12008-10-15 22:01:41 -0700382#define TAINT_PROPRIETARY_MODULE 0
383#define TAINT_FORCED_MODULE 1
384#define TAINT_UNSAFE_SMP 2
385#define TAINT_FORCED_RMMOD 3
386#define TAINT_MACHINE_CHECK 4
387#define TAINT_BAD_PAGE 5
388#define TAINT_USER 6
389#define TAINT_DIE 7
390#define TAINT_OVERRIDDEN_ACPI_TABLE 8
391#define TAINT_WARN 9
Linus Torvalds26e9a392008-10-17 09:50:12 -0700392#define TAINT_CRAP 10
Ben Hutchings92946bc2010-04-03 19:36:42 +0100393#define TAINT_FIRMWARE_WORKAROUND 11
Ben Hutchings2449b8b2011-10-24 15:12:28 +0200394#define TAINT_OOT_MODULE 12
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395
Harvey Harrison3fc95772008-05-14 16:05:49 -0700396extern const char hex_asc[];
397#define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
398#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
399
Andy Shevchenko55036ba2011-10-31 17:12:41 -0700400static inline char *hex_byte_pack(char *buf, u8 byte)
Harvey Harrison3fc95772008-05-14 16:05:49 -0700401{
402 *buf++ = hex_asc_hi(byte);
403 *buf++ = hex_asc_lo(byte);
404 return buf;
405}
Randy Dunlap99eaf3c2007-05-10 22:22:39 -0700406
Andy Shevchenko55036ba2011-10-31 17:12:41 -0700407static inline char * __deprecated pack_hex_byte(char *buf, u8 byte)
408{
409 return hex_byte_pack(buf, byte);
410}
411
Andy Shevchenko903788892010-05-24 14:33:23 -0700412extern int hex_to_bin(char ch);
Mimi Zoharb7804982011-09-20 11:23:49 -0400413extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
Andy Shevchenko903788892010-05-24 14:33:23 -0700414
Joe Perches8a64f332009-12-14 18:00:25 -0800415/*
Ingo Molnar526211b2009-03-05 10:28:45 +0100416 * General tracing related utility functions - trace_printk(),
Steven Rostedt2002c252009-03-05 10:35:56 -0500417 * tracing_on/tracing_off and tracing_start()/tracing_stop
418 *
419 * Use tracing_on/tracing_off when you want to quickly turn on or off
420 * tracing. It simply enables or disables the recording of the trace events.
GeunSik Lim156f5a72009-06-02 15:01:37 +0900421 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
Steven Rostedt2002c252009-03-05 10:35:56 -0500422 * file, which gives a means for the kernel and userspace to interact.
423 * Place a tracing_off() in the kernel where you want tracing to end.
424 * From user space, examine the trace, and then echo 1 > tracing_on
425 * to continue tracing.
426 *
427 * tracing_stop/tracing_start has slightly more overhead. It is used
428 * by things like suspend to ram where disabling the recording of the
429 * trace is not enough, but tracing must actually stop because things
430 * like calling smp_processor_id() may crash the system.
431 *
432 * Most likely, you want to use tracing_on/tracing_off.
Ingo Molnar526211b2009-03-05 10:28:45 +0100433 */
Steven Rostedt2002c252009-03-05 10:35:56 -0500434#ifdef CONFIG_RING_BUFFER
Steven Rostedt2002c252009-03-05 10:35:56 -0500435/* trace_off_permanent stops recording with no way to bring it back */
436void tracing_off_permanent(void);
Steven Rostedt2002c252009-03-05 10:35:56 -0500437#else
Steven Rostedt2002c252009-03-05 10:35:56 -0500438static inline void tracing_off_permanent(void) { }
Steven Rostedt2002c252009-03-05 10:35:56 -0500439#endif
Frederic Weisbeckercecbca92010-04-18 19:08:41 +0200440
441enum ftrace_dump_mode {
442 DUMP_NONE,
443 DUMP_ALL,
444 DUMP_ORIG,
445};
446
Ingo Molnar526211b2009-03-05 10:28:45 +0100447#ifdef CONFIG_TRACING
Steven Rostedt93d68e52012-03-20 12:28:29 -0400448void tracing_on(void);
449void tracing_off(void);
450int tracing_is_on(void);
451
Ingo Molnar526211b2009-03-05 10:28:45 +0100452extern void tracing_start(void);
453extern void tracing_stop(void);
454extern void ftrace_off_permanent(void);
455
Joe Perchesb9075fa2011-10-31 17:11:33 -0700456static inline __printf(1, 2)
457void ____trace_printk_check_format(const char *fmt, ...)
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100458{
459}
460#define __trace_printk_check_format(fmt, args...) \
461do { \
462 if (0) \
463 ____trace_printk_check_format(fmt, ##args); \
464} while (0)
465
Ingo Molnar526211b2009-03-05 10:28:45 +0100466/**
467 * trace_printk - printf formatting in the ftrace buffer
468 * @fmt: the printf format for printing
469 *
470 * Note: __trace_printk is an internal function for trace_printk and
471 * the @ip is passed in via the trace_printk macro.
472 *
473 * This function allows a kernel developer to debug fast path sections
474 * that printk is not appropriate for. By scattering in various
475 * printk like tracing in the code, a developer can quickly see
476 * where problems are occurring.
477 *
478 * This is intended as a debugging tool for the developer only.
479 * Please refrain from leaving trace_printks scattered around in
480 * your code.
481 */
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100482
483#define trace_printk(fmt, args...) \
484do { \
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100485 __trace_printk_check_format(fmt, ##args); \
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100486 if (__builtin_constant_p(fmt)) { \
487 static const char *trace_printk_fmt \
488 __attribute__((section("__trace_printk_fmt"))) = \
489 __builtin_constant_p(fmt) ? fmt : NULL; \
490 \
491 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
492 } else \
493 __trace_printk(_THIS_IP_, fmt, ##args); \
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100494} while (0)
495
Joe Perchesb9075fa2011-10-31 17:11:33 -0700496extern __printf(2, 3)
497int __trace_bprintk(unsigned long ip, const char *fmt, ...);
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100498
Joe Perchesb9075fa2011-10-31 17:11:33 -0700499extern __printf(2, 3)
500int __trace_printk(unsigned long ip, const char *fmt, ...);
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100501
Steven Rostedt03889382009-12-11 09:48:22 -0500502extern void trace_dump_stack(void);
503
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100504/*
505 * The double __builtin_constant_p is because gcc will give us an error
506 * if we try to allocate the static variable to fmt if it is not a
507 * constant. Even with the outer if statement.
508 */
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100509#define ftrace_vprintk(fmt, vargs) \
510do { \
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100511 if (__builtin_constant_p(fmt)) { \
512 static const char *trace_printk_fmt \
513 __attribute__((section("__trace_printk_fmt"))) = \
514 __builtin_constant_p(fmt) ? fmt : NULL; \
Ingo Molnar7bffc232009-03-09 10:11:36 +0100515 \
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100516 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
517 } else \
518 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100519} while (0)
520
Ingo Molnar526211b2009-03-05 10:28:45 +0100521extern int
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100522__ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
523
524extern int
Ingo Molnar526211b2009-03-05 10:28:45 +0100525__ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100526
Frederic Weisbeckercecbca92010-04-18 19:08:41 +0200527extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
Ingo Molnar526211b2009-03-05 10:28:45 +0100528#else
Joe Perchesb9075fa2011-10-31 17:11:33 -0700529static inline __printf(1, 2)
530int trace_printk(const char *fmt, ...);
Ingo Molnar526211b2009-03-05 10:28:45 +0100531
532static inline void tracing_start(void) { }
533static inline void tracing_stop(void) { }
534static inline void ftrace_off_permanent(void) { }
Steven Rostedte36c5452009-12-14 15:58:33 -0500535static inline void trace_dump_stack(void) { }
Steven Rostedt93d68e52012-03-20 12:28:29 -0400536
537static inline void tracing_on(void) { }
538static inline void tracing_off(void) { }
539static inline int tracing_is_on(void) { return 0; }
540
Ingo Molnar526211b2009-03-05 10:28:45 +0100541static inline int
542trace_printk(const char *fmt, ...)
543{
544 return 0;
545}
546static inline int
547ftrace_vprintk(const char *fmt, va_list ap)
548{
549 return 0;
550}
Frederic Weisbeckercecbca92010-04-18 19:08:41 +0200551static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100552#endif /* CONFIG_TRACING */
Ingo Molnar526211b2009-03-05 10:28:45 +0100553
554/*
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700555 * min()/max()/clamp() macros that also do
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556 * strict type-checking.. See the
557 * "unnecessary" pointer comparison.
558 */
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700559#define min(x, y) ({ \
560 typeof(x) _min1 = (x); \
561 typeof(y) _min2 = (y); \
562 (void) (&_min1 == &_min2); \
563 _min1 < _min2 ? _min1 : _min2; })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700565#define max(x, y) ({ \
566 typeof(x) _max1 = (x); \
567 typeof(y) _max2 = (y); \
568 (void) (&_max1 == &_max2); \
569 _max1 > _max2 ? _max1 : _max2; })
570
Hagen Paul Pfeiferf27c85c2010-10-26 14:22:21 -0700571#define min3(x, y, z) ({ \
572 typeof(x) _min1 = (x); \
573 typeof(y) _min2 = (y); \
574 typeof(z) _min3 = (z); \
575 (void) (&_min1 == &_min2); \
576 (void) (&_min1 == &_min3); \
577 _min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \
578 (_min2 < _min3 ? _min2 : _min3); })
579
580#define max3(x, y, z) ({ \
581 typeof(x) _max1 = (x); \
582 typeof(y) _max2 = (y); \
583 typeof(z) _max3 = (z); \
584 (void) (&_max1 == &_max2); \
585 (void) (&_max1 == &_max3); \
586 _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \
587 (_max2 > _max3 ? _max2 : _max3); })
588
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700589/**
Martin K. Petersenc8bf1332010-09-10 20:07:38 +0200590 * min_not_zero - return the minimum that is _not_ zero, unless both are zero
591 * @x: value1
592 * @y: value2
593 */
594#define min_not_zero(x, y) ({ \
595 typeof(x) __x = (x); \
596 typeof(y) __y = (y); \
597 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
598
599/**
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700600 * clamp - return a value clamped to a given range with strict typechecking
601 * @val: current value
602 * @min: minimum allowable value
603 * @max: maximum allowable value
604 *
605 * This macro does strict typechecking of min/max to make sure they are of the
606 * same type as val. See the unnecessary pointer comparisons.
607 */
608#define clamp(val, min, max) ({ \
609 typeof(val) __val = (val); \
610 typeof(min) __min = (min); \
611 typeof(max) __max = (max); \
612 (void) (&__val == &__min); \
613 (void) (&__val == &__max); \
614 __val = __val < __min ? __min: __val; \
615 __val > __max ? __max: __val; })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616
617/*
618 * ..and if you can't take the strict
619 * types, you can specify one yourself.
620 *
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700621 * Or not use min/max/clamp at all, of course.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 */
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700623#define min_t(type, x, y) ({ \
624 type __min1 = (x); \
625 type __min2 = (y); \
626 __min1 < __min2 ? __min1: __min2; })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700628#define max_t(type, x, y) ({ \
629 type __max1 = (x); \
630 type __max2 = (y); \
631 __max1 > __max2 ? __max1: __max2; })
632
633/**
634 * clamp_t - return a value clamped to a given range using a given type
635 * @type: the type of variable to use
636 * @val: current value
637 * @min: minimum allowable value
638 * @max: maximum allowable value
639 *
640 * This macro does no typechecking and uses temporary variables of type
641 * 'type' to make all the comparisons.
642 */
643#define clamp_t(type, val, min, max) ({ \
644 type __val = (val); \
645 type __min = (min); \
646 type __max = (max); \
647 __val = __val < __min ? __min: __val; \
648 __val > __max ? __max: __val; })
649
650/**
651 * clamp_val - return a value clamped to a given range using val's type
652 * @val: current value
653 * @min: minimum allowable value
654 * @max: maximum allowable value
655 *
656 * This macro does no typechecking and uses temporary variables of whatever
657 * type the input argument 'val' is. This is useful when val is an unsigned
658 * type and min and max are literals that will otherwise be assigned a signed
659 * integer type.
660 */
661#define clamp_val(val, min, max) ({ \
662 typeof(val) __val = (val); \
663 typeof(val) __min = (min); \
664 typeof(val) __max = (max); \
665 __val = __val < __min ? __min: __val; \
666 __val > __max ? __max: __val; })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667
Wu Fengguang91f68b72009-01-07 18:09:12 -0800668
669/*
670 * swap - swap value of @a and @b
671 */
Peter Zijlstraac7b9002009-02-04 15:11:59 -0800672#define swap(a, b) \
673 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
Wu Fengguang91f68b72009-01-07 18:09:12 -0800674
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675/**
676 * container_of - cast a member of a structure out to the containing structure
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 * @ptr: the pointer to the member.
678 * @type: the type of the container struct this is embedded in.
679 * @member: the name of the member within the struct.
680 *
681 */
682#define container_of(ptr, type, member) ({ \
Daniel Walker78db2ad2007-05-12 16:28:35 -0700683 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
684 (type *)( (char *)__mptr - offsetof(type,member) );})
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685
Arnaud Lacombeb9d4f422011-07-25 17:13:03 -0700686/* Trap pasters of __FUNCTION__ at compile-time */
687#define __FUNCTION__ (__func__)
688
689/* This helps us to avoid #ifdef CONFIG_NUMA */
690#ifdef CONFIG_NUMA
691#define NUMA_BUILD 1
692#else
693#define NUMA_BUILD 0
694#endif
695
696/* This helps us avoid #ifdef CONFIG_COMPACTION */
697#ifdef CONFIG_COMPACTION
698#define COMPACTION_BUILD 1
699#else
700#define COMPACTION_BUILD 0
701#endif
702
703/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
704#ifdef CONFIG_FTRACE_MCOUNT_RECORD
705# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
706#endif
WANG Cong9d00f922011-07-25 17:13:02 -0700707
WANG Cong9d00f922011-07-25 17:13:02 -0700708extern int do_sysinfo(struct sysinfo *info);
709
710#endif /* __KERNEL__ */
711
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712#endif