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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_KERNEL_H
2#define _LINUX_KERNEL_H
3
4/*
5 * 'kernel.h' contains some often-used function prototypes etc
6 */
7
8#ifdef __KERNEL__
9
10#include <stdarg.h>
11#include <linux/linkage.h>
12#include <linux/stddef.h>
13#include <linux/types.h>
14#include <linux/compiler.h>
15#include <linux/bitops.h>
David Howellsf0d1b0b2006-12-08 02:37:49 -080016#include <linux/log2.h>
Andrew Mortone0deaff42008-07-25 01:45:24 -070017#include <linux/typecheck.h>
Dave Young717115e2008-07-25 01:45:58 -070018#include <linux/ratelimit.h>
Jason Barone9d376f2009-02-05 11:51:38 -050019#include <linux/dynamic_debug.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <asm/byteorder.h>
21#include <asm/bug.h>
22
Roman Zippel3eb3c742007-01-10 14:45:28 +010023extern const char linux_banner[];
24extern const char linux_proc_banner[];
25
Zhang, Yanmin44f564a2008-04-29 01:00:55 -070026#define USHORT_MAX ((u16)(~0U))
27#define SHORT_MAX ((s16)(USHORT_MAX>>1))
28#define SHORT_MIN (-SHORT_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
Linus Torvalds2ea58142006-11-26 19:05:22 -080041#define ALIGN(x,a) __ALIGN_MASK(x,(typeof(x))(a)-1)
42#define __ALIGN_MASK(x,mask) (((x)+(mask))&~(mask))
Matthew Wilcoxa83308e2007-09-11 15:23:47 -070043#define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
Herbert Xuf10db622008-02-06 01:37:05 -080044#define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
Linus Torvalds2ea58142006-11-26 19:05:22 -080045
Rusty Russellc5e631cf2007-05-06 14:51:05 -070046#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
47
Jan Beulich4552d5d2006-06-26 13:57:28 +020048#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
Steven Whitehouse930631e2006-09-25 23:32:40 -070049#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
David Howellsb4cac1a2006-07-10 04:44:54 -070050#define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
Darrick J. Wong9fe06082009-01-06 14:40:51 -080051#define DIV_ROUND_CLOSEST(x, divisor)( \
52{ \
53 typeof(divisor) __divisor = divisor; \
54 (((x) + ((__divisor) / 2)) / (__divisor)); \
55} \
56)
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
Eduard - Gabriel Munteanuca31e142008-07-05 12:14:23 +030058#define _RET_IP_ (unsigned long)__builtin_return_address(0)
59#define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
60
Jens Axboe2da96ac2007-10-12 12:40:38 +020061#ifdef CONFIG_LBD
62# include <asm/div64.h>
63# define sector_div(a, b) do_div(a, b)
64#else
65# define sector_div(n, b)( \
66{ \
67 int _res; \
68 _res = (n) % (b); \
69 (n) /= (b); \
70 _res; \
71} \
72)
73#endif
74
Andrew Morton218e1802007-05-10 03:15:18 -070075/**
76 * upper_32_bits - return bits 32-63 of a number
77 * @n: the number we're accessing
78 *
79 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
80 * the "right shift count >= width of type" warning when that quantity is
81 * 32-bits.
82 */
83#define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
84
Joerg Roedel204b8852008-07-29 22:33:42 -070085/**
86 * lower_32_bits - return bits 0-31 of a number
87 * @n: the number we're accessing
88 */
89#define lower_32_bits(n) ((u32)(n))
90
Linus Torvalds1da177e2005-04-16 15:20:36 -070091#define KERN_EMERG "<0>" /* system is unusable */
92#define KERN_ALERT "<1>" /* action must be taken immediately */
93#define KERN_CRIT "<2>" /* critical conditions */
94#define KERN_ERR "<3>" /* error conditions */
95#define KERN_WARNING "<4>" /* warning conditions */
96#define KERN_NOTICE "<5>" /* normal but significant condition */
97#define KERN_INFO "<6>" /* informational */
98#define KERN_DEBUG "<7>" /* debug-level messages */
99
Linus Torvaldse28d7132009-06-16 11:02:28 -0700100/* Use the default kernel loglevel */
101#define KERN_DEFAULT "<d>"
Ingo Molnar47492522007-10-16 23:30:29 -0700102/*
103 * Annotation for a "continued" line of log printout (only done after a
104 * line that had no enclosing \n). Only to be used by core/arch code
105 * during early bootup (a continued line is not SMP-safe otherwise).
106 */
Linus Torvalds5fd29d62009-06-16 10:57:02 -0700107#define KERN_CONT "<c>"
Ingo Molnar47492522007-10-16 23:30:29 -0700108
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109extern int console_printk[];
110
111#define console_loglevel (console_printk[0])
112#define default_message_loglevel (console_printk[1])
113#define minimum_console_loglevel (console_printk[2])
114#define default_console_loglevel (console_printk[3])
115
116struct completion;
akpm@osdl.orgdf2e71f2006-01-09 20:51:37 -0800117struct pt_regs;
118struct user;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119
Uwe Kleine-König070cb062008-08-12 15:08:59 -0700120#ifdef CONFIG_PREEMPT_VOLUNTARY
121extern int _cond_resched(void);
122# define might_resched() _cond_resched()
123#else
124# define might_resched() do { } while (0)
125#endif
126
Randy Dunlap7106a272008-10-29 14:01:15 -0700127#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
128 void __might_sleep(char *file, int line);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129/**
130 * might_sleep - annotation for functions that can sleep
131 *
132 * this macro will print a stack trace if it is executed in an atomic
133 * context (spinlock, irq-handler, ...).
134 *
135 * This is a useful debugging help to be able to catch problems early and not
Jim Cromiee20ec992006-11-30 04:46:13 +0100136 * be bitten later when the calling function happens to sleep when it is not
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 * supposed to.
138 */
Ingo Molnarf8cbd992005-06-25 14:57:39 -0700139# define might_sleep() \
140 do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
141#else
142# define might_sleep() do { might_resched(); } while (0)
143#endif
144
Hua Zhong368a5fa2006-06-23 02:05:42 -0700145#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
Ingo Molnarf8cbd992005-06-25 14:57:39 -0700146
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147#define abs(x) ({ \
148 int __x = (x); \
149 (__x < 0) ? -__x : __x; \
150 })
151
Nick Piggin3ee1afa2008-09-10 13:37:17 +0200152#ifdef CONFIG_PROVE_LOCKING
153void might_fault(void);
154#else
155static inline void might_fault(void)
156{
157 might_sleep();
158}
159#endif
160
Alan Sterne041c682006-03-27 01:16:30 -0800161extern struct atomic_notifier_head panic_notifier_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162extern long (*panic_blink)(long time);
163NORET_TYPE void panic(const char * fmt, ...)
Andi Kleena586df02007-07-21 17:10:00 +0200164 __attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
Andrew Mortondd287792006-03-23 03:00:57 -0800165extern void oops_enter(void);
166extern void oops_exit(void);
167extern int oops_may_print(void);
Harvey Harrisonec701582008-02-08 04:19:55 -0800168NORET_TYPE void do_exit(long error_code)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 ATTRIB_NORET;
170NORET_TYPE void complete_and_exit(struct completion *, long)
171 ATTRIB_NORET;
172extern unsigned long simple_strtoul(const char *,char **,unsigned int);
173extern long simple_strtol(const char *,char **,unsigned int);
174extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
175extern long long simple_strtoll(const char *,char **,unsigned int);
Yi Yang06b2a762008-02-08 04:21:57 -0800176extern int strict_strtoul(const char *, unsigned int, unsigned long *);
177extern int strict_strtol(const char *, unsigned int, long *);
178extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
179extern int strict_strtoll(const char *, unsigned int, long long *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180extern int sprintf(char * buf, const char * fmt, ...)
181 __attribute__ ((format (printf, 2, 3)));
182extern int vsprintf(char *buf, const char *, va_list)
183 __attribute__ ((format (printf, 2, 0)));
184extern int snprintf(char * buf, size_t size, const char * fmt, ...)
185 __attribute__ ((format (printf, 3, 4)));
186extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
187 __attribute__ ((format (printf, 3, 0)));
188extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
189 __attribute__ ((format (printf, 3, 4)));
190extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
191 __attribute__ ((format (printf, 3, 0)));
Jeremy Fitzhardingee9059142006-06-25 05:49:17 -0700192extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
193 __attribute__ ((format (printf, 2, 3)));
Jeremy Fitzhardinge11443ec2007-04-30 15:09:56 -0700194extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195
196extern int sscanf(const char *, const char *, ...)
197 __attribute__ ((format (scanf, 2, 3)));
198extern int vsscanf(const char *, const char *, va_list)
199 __attribute__ ((format (scanf, 2, 0)));
200
201extern int get_option(char **str, int *pint);
202extern char *get_options(const char *str, int nints, int *ints);
Jeremy Fitzhardinged974ae32008-07-24 16:27:46 -0700203extern unsigned long long memparse(const char *ptr, char **retptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204
Trent Piepho5e376612006-05-15 09:44:06 -0700205extern int core_kernel_text(unsigned long addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206extern int __kernel_text_address(unsigned long addr);
207extern int kernel_text_address(unsigned long addr);
Arjan van de Venab7476c2008-08-15 15:29:38 -0700208extern int func_ptr_is_kernel_text(void *ptr);
Arjan van de Venab7476c2008-08-15 15:29:38 -0700209
Eric W. Biederman04a2e6a2007-02-12 00:52:56 -0800210struct pid;
211extern struct pid *session_of_pgrp(struct pid *pgrp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212
Thomas Renningera0ad05c2008-09-01 14:27:02 +0200213/*
214 * FW_BUG
215 * Add this to a message where you are sure the firmware is buggy or behaves
216 * really stupid or out of spec. Be aware that the responsible BIOS developer
217 * should be able to fix this issue or at least get a concrete idea of the
218 * problem by reading your message without the need of looking at the kernel
219 * code.
220 *
221 * Use it for definite and high priority BIOS bugs.
222 *
223 * FW_WARN
224 * Use it for not that clear (e.g. could the kernel messed up things already?)
225 * and medium priority BIOS bugs.
226 *
227 * FW_INFO
228 * Use this one if you want to tell the user or vendor about something
229 * suspicious, but generally harmless related to the firmware.
230 *
231 * Use it for information or very low priority BIOS bugs.
232 */
233#define FW_BUG "[Firmware Bug]: "
234#define FW_WARN "[Firmware Warn]: "
235#define FW_INFO "[Firmware Info]: "
236
Matt Mackalld59745c2005-05-01 08:59:02 -0700237#ifdef CONFIG_PRINTK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238asmlinkage int vprintk(const char *fmt, va_list args)
239 __attribute__ ((format (printf, 1, 0)));
240asmlinkage int printk(const char * fmt, ...)
Andi Kleena586df02007-07-21 17:10:00 +0200241 __attribute__ ((format (printf, 1, 2))) __cold;
Joe Perches7ef3d2f2008-02-08 04:21:25 -0800242
Dave Young717115e2008-07-25 01:45:58 -0700243extern struct ratelimit_state printk_ratelimit_state;
Joe Perches7ef3d2f2008-02-08 04:21:25 -0800244extern int printk_ratelimit(void);
Joe Perches7ef3d2f2008-02-08 04:21:25 -0800245extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
246 unsigned int interval_msec);
Ingo Molnarf036be92009-02-05 13:45:43 +0100247
248/*
249 * Print a one-time message (analogous to WARN_ONCE() et al):
250 */
251#define printk_once(x...) ({ \
252 static int __print_once = 1; \
253 \
254 if (__print_once) { \
255 __print_once = 0; \
256 printk(x); \
257 } \
258})
259
Neil Horman04d491a2009-04-02 16:58:57 -0700260void log_buf_kexec_setup(void);
Matt Mackalld59745c2005-05-01 08:59:02 -0700261#else
262static inline int vprintk(const char *s, va_list args)
263 __attribute__ ((format (printf, 1, 0)));
264static inline int vprintk(const char *s, va_list args) { return 0; }
265static inline int printk(const char *s, ...)
266 __attribute__ ((format (printf, 1, 2)));
Andi Kleena586df02007-07-21 17:10:00 +0200267static inline int __cold printk(const char *s, ...) { return 0; }
Joe Perches7ef3d2f2008-02-08 04:21:25 -0800268static inline int printk_ratelimit(void) { return 0; }
Joe Perches7ef3d2f2008-02-08 04:21:25 -0800269static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
270 unsigned int interval_msec) \
271 { return false; }
Ingo Molnarf036be92009-02-05 13:45:43 +0100272
273/* No effect, but we still get type checking even in the !PRINTK case: */
274#define printk_once(x...) printk(x)
275
Neil Horman04d491a2009-04-02 16:58:57 -0700276static inline void log_buf_kexec_setup(void)
277{
278}
Matt Mackalld59745c2005-05-01 08:59:02 -0700279#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280
Ingo Molnarced9cd42008-08-11 14:38:12 +0200281extern int printk_needs_cpu(int cpu);
282extern void printk_tick(void);
283
Jiri Slabye17ba732008-05-12 15:44:40 +0200284extern void asmlinkage __attribute__((format(printf, 1, 2)))
Ingo Molnar076f9772008-01-30 13:33:06 +0100285 early_printk(const char *fmt, ...);
286
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287unsigned long int_sqrt(unsigned long);
288
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289static inline void console_silent(void)
290{
291 console_loglevel = 0;
292}
293
294static inline void console_verbose(void)
295{
296 if (console_loglevel)
297 console_loglevel = 15;
298}
299
300extern void bust_spinlocks(int yes);
Kirill Korotaeve3e8a752007-02-10 01:46:19 -0800301extern void wake_up_klogd(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
Adrian Bunkaa727102006-04-10 22:53:59 -0700303extern int panic_timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304extern int panic_on_oops;
Don Zickus8da5add2006-09-26 10:52:27 +0200305extern int panic_on_unrecovered_nmi;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306extern const char *print_tainted(void);
Andi Kleen25ddbb12008-10-15 22:01:41 -0700307extern void add_taint(unsigned flag);
308extern int test_taint(unsigned flag);
309extern unsigned long get_taint(void);
David Howellsb920de12008-02-08 04:19:31 -0800310extern int root_mountflags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311
312/* Values used for system_state */
313extern enum system_states {
314 SYSTEM_BOOTING,
315 SYSTEM_RUNNING,
316 SYSTEM_HALT,
317 SYSTEM_POWER_OFF,
318 SYSTEM_RESTART,
Alexey Starikovskiy729b4d42005-12-01 04:29:00 -0500319 SYSTEM_SUSPEND_DISK,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320} system_state;
321
Andi Kleen25ddbb12008-10-15 22:01:41 -0700322#define TAINT_PROPRIETARY_MODULE 0
323#define TAINT_FORCED_MODULE 1
324#define TAINT_UNSAFE_SMP 2
325#define TAINT_FORCED_RMMOD 3
326#define TAINT_MACHINE_CHECK 4
327#define TAINT_BAD_PAGE 5
328#define TAINT_USER 6
329#define TAINT_DIE 7
330#define TAINT_OVERRIDDEN_ACPI_TABLE 8
331#define TAINT_WARN 9
Linus Torvalds26e9a392008-10-17 09:50:12 -0700332#define TAINT_CRAP 10
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333
Andi Kleena586df02007-07-21 17:10:00 +0200334extern void dump_stack(void) __cold;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335
Randy Dunlap99eaf3c2007-05-10 22:22:39 -0700336enum {
337 DUMP_PREFIX_NONE,
338 DUMP_PREFIX_ADDRESS,
339 DUMP_PREFIX_OFFSET
340};
Randy Dunlapc7909232007-06-08 13:47:04 -0700341extern void hex_dump_to_buffer(const void *buf, size_t len,
342 int rowsize, int groupsize,
343 char *linebuf, size_t linebuflen, bool ascii);
344extern void print_hex_dump(const char *level, const char *prefix_str,
345 int prefix_type, int rowsize, int groupsize,
Artem Bityutskiy6a0ed912007-08-07 23:43:14 +0300346 const void *buf, size_t len, bool ascii);
Randy Dunlapc7909232007-06-08 13:47:04 -0700347extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
Alan Sterneb9a9a52007-08-10 13:01:07 -0700348 const void *buf, size_t len);
Harvey Harrison3fc95772008-05-14 16:05:49 -0700349
350extern const char hex_asc[];
351#define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
352#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
353
354static inline char *pack_hex_byte(char *buf, u8 byte)
355{
356 *buf++ = hex_asc_hi(byte);
357 *buf++ = hex_asc_lo(byte);
358 return buf;
359}
Randy Dunlap99eaf3c2007-05-10 22:22:39 -0700360
Martin Schwidefskyd091c2f2008-11-12 21:16:43 +0100361#ifndef pr_fmt
362#define pr_fmt(fmt) fmt
363#endif
364
365#define pr_emerg(fmt, ...) \
366 printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
367#define pr_alert(fmt, ...) \
368 printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
369#define pr_crit(fmt, ...) \
370 printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
371#define pr_err(fmt, ...) \
372 printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
373#define pr_warning(fmt, ...) \
374 printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
375#define pr_notice(fmt, ...) \
376 printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
377#define pr_info(fmt, ...) \
378 printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
Cyrill Gorcunov311d0762009-03-31 15:23:51 -0700379#define pr_cont(fmt, ...) \
380 printk(KERN_CONT fmt, ##__VA_ARGS__)
Emil Medve1f7c8232007-10-16 23:29:48 -0700381
Michael Ellerman4ccb4572009-04-09 14:48:24 -0700382/* pr_devel() should produce zero code unless DEBUG is defined */
383#ifdef DEBUG
384#define pr_devel(fmt, ...) \
385 printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
386#else
387#define pr_devel(fmt, ...) \
388 ({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
389#endif
390
Pavel Machek1cc6daf2006-08-08 01:37:15 +0200391/* If you are writing a driver, please use dev_dbg instead */
Cornelia Huckd0d85ff2008-12-04 16:55:47 +0100392#if defined(DEBUG)
393#define pr_debug(fmt, ...) \
394 printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
Jason Barone9d376f2009-02-05 11:51:38 -0500395#elif defined(CONFIG_DYNAMIC_DEBUG)
Greg Bankse6e66b02009-03-11 21:07:28 +1100396/* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
Jason Baron346e15b2008-08-12 16:46:19 -0400397#define pr_debug(fmt, ...) do { \
Greg Bankse6e66b02009-03-11 21:07:28 +1100398 dynamic_pr_debug(fmt, ##__VA_ARGS__); \
Jason Baron346e15b2008-08-12 16:46:19 -0400399 } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400#else
Martin Schwidefskyd091c2f2008-11-12 21:16:43 +0100401#define pr_debug(fmt, ...) \
402 ({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403#endif
404
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405/*
Ingo Molnar526211b2009-03-05 10:28:45 +0100406 * General tracing related utility functions - trace_printk(),
Steven Rostedt2002c252009-03-05 10:35:56 -0500407 * tracing_on/tracing_off and tracing_start()/tracing_stop
408 *
409 * Use tracing_on/tracing_off when you want to quickly turn on or off
410 * tracing. It simply enables or disables the recording of the trace events.
411 * This also corresponds to the user space debugfs/tracing/tracing_on
412 * file, which gives a means for the kernel and userspace to interact.
413 * Place a tracing_off() in the kernel where you want tracing to end.
414 * From user space, examine the trace, and then echo 1 > tracing_on
415 * to continue tracing.
416 *
417 * tracing_stop/tracing_start has slightly more overhead. It is used
418 * by things like suspend to ram where disabling the recording of the
419 * trace is not enough, but tracing must actually stop because things
420 * like calling smp_processor_id() may crash the system.
421 *
422 * Most likely, you want to use tracing_on/tracing_off.
Ingo Molnar526211b2009-03-05 10:28:45 +0100423 */
Steven Rostedt2002c252009-03-05 10:35:56 -0500424#ifdef CONFIG_RING_BUFFER
425void tracing_on(void);
426void tracing_off(void);
427/* trace_off_permanent stops recording with no way to bring it back */
428void tracing_off_permanent(void);
429int tracing_is_on(void);
430#else
431static inline void tracing_on(void) { }
432static inline void tracing_off(void) { }
433static inline void tracing_off_permanent(void) { }
434static inline int tracing_is_on(void) { return 0; }
435#endif
Ingo Molnar526211b2009-03-05 10:28:45 +0100436#ifdef CONFIG_TRACING
437extern void tracing_start(void);
438extern void tracing_stop(void);
439extern void ftrace_off_permanent(void);
440
441extern void
442ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
443
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100444static inline void __attribute__ ((format (printf, 1, 2)))
445____trace_printk_check_format(const char *fmt, ...)
446{
447}
448#define __trace_printk_check_format(fmt, args...) \
449do { \
450 if (0) \
451 ____trace_printk_check_format(fmt, ##args); \
452} while (0)
453
Ingo Molnar526211b2009-03-05 10:28:45 +0100454/**
455 * trace_printk - printf formatting in the ftrace buffer
456 * @fmt: the printf format for printing
457 *
458 * Note: __trace_printk is an internal function for trace_printk and
459 * the @ip is passed in via the trace_printk macro.
460 *
461 * This function allows a kernel developer to debug fast path sections
462 * that printk is not appropriate for. By scattering in various
463 * printk like tracing in the code, a developer can quickly see
464 * where problems are occurring.
465 *
466 * This is intended as a debugging tool for the developer only.
467 * Please refrain from leaving trace_printks scattered around in
468 * your code.
469 */
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100470
471#define trace_printk(fmt, args...) \
472do { \
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100473 __trace_printk_check_format(fmt, ##args); \
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100474 if (__builtin_constant_p(fmt)) { \
475 static const char *trace_printk_fmt \
476 __attribute__((section("__trace_printk_fmt"))) = \
477 __builtin_constant_p(fmt) ? fmt : NULL; \
478 \
479 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
480 } else \
481 __trace_printk(_THIS_IP_, fmt, ##args); \
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100482} while (0)
483
Ingo Molnar526211b2009-03-05 10:28:45 +0100484extern int
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100485__trace_bprintk(unsigned long ip, const char *fmt, ...)
486 __attribute__ ((format (printf, 2, 3)));
487
488extern int
Ingo Molnar526211b2009-03-05 10:28:45 +0100489__trace_printk(unsigned long ip, const char *fmt, ...)
490 __attribute__ ((format (printf, 2, 3)));
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100491
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100492/*
493 * The double __builtin_constant_p is because gcc will give us an error
494 * if we try to allocate the static variable to fmt if it is not a
495 * constant. Even with the outer if statement.
496 */
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100497#define ftrace_vprintk(fmt, vargs) \
498do { \
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100499 if (__builtin_constant_p(fmt)) { \
500 static const char *trace_printk_fmt \
501 __attribute__((section("__trace_printk_fmt"))) = \
502 __builtin_constant_p(fmt) ? fmt : NULL; \
Ingo Molnar7bffc232009-03-09 10:11:36 +0100503 \
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100504 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
505 } else \
506 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100507} while (0)
508
Ingo Molnar526211b2009-03-05 10:28:45 +0100509extern int
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100510__ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
511
512extern int
Ingo Molnar526211b2009-03-05 10:28:45 +0100513__ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100514
Ingo Molnar526211b2009-03-05 10:28:45 +0100515extern void ftrace_dump(void);
516#else
517static inline void
518ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
519static inline int
520trace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
521
522static inline void tracing_start(void) { }
523static inline void tracing_stop(void) { }
524static inline void ftrace_off_permanent(void) { }
525static inline int
526trace_printk(const char *fmt, ...)
527{
528 return 0;
529}
530static inline int
531ftrace_vprintk(const char *fmt, va_list ap)
532{
533 return 0;
534}
535static inline void ftrace_dump(void) { }
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100536#endif /* CONFIG_TRACING */
Ingo Molnar526211b2009-03-05 10:28:45 +0100537
538/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 * Display an IP address in readable format.
540 */
541
542#define NIPQUAD(addr) \
543 ((unsigned char *)&addr)[0], \
544 ((unsigned char *)&addr)[1], \
545 ((unsigned char *)&addr)[2], \
546 ((unsigned char *)&addr)[3]
Joe Perches46b86a22006-01-13 14:29:07 -0800547#define NIPQUAD_FMT "%u.%u.%u.%u"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549/*
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700550 * min()/max()/clamp() macros that also do
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 * strict type-checking.. See the
552 * "unnecessary" pointer comparison.
553 */
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700554#define min(x, y) ({ \
555 typeof(x) _min1 = (x); \
556 typeof(y) _min2 = (y); \
557 (void) (&_min1 == &_min2); \
558 _min1 < _min2 ? _min1 : _min2; })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700560#define max(x, y) ({ \
561 typeof(x) _max1 = (x); \
562 typeof(y) _max2 = (y); \
563 (void) (&_max1 == &_max2); \
564 _max1 > _max2 ? _max1 : _max2; })
565
566/**
567 * clamp - return a value clamped to a given range with strict typechecking
568 * @val: current value
569 * @min: minimum allowable value
570 * @max: maximum allowable value
571 *
572 * This macro does strict typechecking of min/max to make sure they are of the
573 * same type as val. See the unnecessary pointer comparisons.
574 */
575#define clamp(val, min, max) ({ \
576 typeof(val) __val = (val); \
577 typeof(min) __min = (min); \
578 typeof(max) __max = (max); \
579 (void) (&__val == &__min); \
580 (void) (&__val == &__max); \
581 __val = __val < __min ? __min: __val; \
582 __val > __max ? __max: __val; })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583
584/*
585 * ..and if you can't take the strict
586 * types, you can specify one yourself.
587 *
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700588 * Or not use min/max/clamp at all, of course.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589 */
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700590#define min_t(type, x, y) ({ \
591 type __min1 = (x); \
592 type __min2 = (y); \
593 __min1 < __min2 ? __min1: __min2; })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700595#define max_t(type, x, y) ({ \
596 type __max1 = (x); \
597 type __max2 = (y); \
598 __max1 > __max2 ? __max1: __max2; })
599
600/**
601 * clamp_t - return a value clamped to a given range using a given type
602 * @type: the type of variable to use
603 * @val: current value
604 * @min: minimum allowable value
605 * @max: maximum allowable value
606 *
607 * This macro does no typechecking and uses temporary variables of type
608 * 'type' to make all the comparisons.
609 */
610#define clamp_t(type, val, min, max) ({ \
611 type __val = (val); \
612 type __min = (min); \
613 type __max = (max); \
614 __val = __val < __min ? __min: __val; \
615 __val > __max ? __max: __val; })
616
617/**
618 * clamp_val - return a value clamped to a given range using val's type
619 * @val: current value
620 * @min: minimum allowable value
621 * @max: maximum allowable value
622 *
623 * This macro does no typechecking and uses temporary variables of whatever
624 * type the input argument 'val' is. This is useful when val is an unsigned
625 * type and min and max are literals that will otherwise be assigned a signed
626 * integer type.
627 */
628#define clamp_val(val, min, max) ({ \
629 typeof(val) __val = (val); \
630 typeof(val) __min = (min); \
631 typeof(val) __max = (max); \
632 __val = __val < __min ? __min: __val; \
633 __val > __max ? __max: __val; })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634
Wu Fengguang91f68b72009-01-07 18:09:12 -0800635
636/*
637 * swap - swap value of @a and @b
638 */
Peter Zijlstraac7b9002009-02-04 15:11:59 -0800639#define swap(a, b) \
640 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
Wu Fengguang91f68b72009-01-07 18:09:12 -0800641
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642/**
643 * container_of - cast a member of a structure out to the containing structure
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 * @ptr: the pointer to the member.
645 * @type: the type of the container struct this is embedded in.
646 * @member: the name of the member within the struct.
647 *
648 */
649#define container_of(ptr, type, member) ({ \
Daniel Walker78db2ad2007-05-12 16:28:35 -0700650 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
651 (type *)( (char *)__mptr - offsetof(type,member) );})
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652
Kyle McMartind4d23ad2007-02-10 01:46:00 -0800653struct sysinfo;
654extern int do_sysinfo(struct sysinfo *info);
655
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656#endif /* __KERNEL__ */
657
658#define SI_LOAD_SHIFT 16
659struct sysinfo {
660 long uptime; /* Seconds since boot */
661 unsigned long loads[3]; /* 1, 5, and 15 minute load averages */
662 unsigned long totalram; /* Total usable main memory size */
663 unsigned long freeram; /* Available memory size */
664 unsigned long sharedram; /* Amount of shared memory */
665 unsigned long bufferram; /* Memory used by buffers */
666 unsigned long totalswap; /* Total swap space size */
667 unsigned long freeswap; /* swap space still available */
668 unsigned short procs; /* Number of current processes */
669 unsigned short pad; /* explicit padding for m68k */
670 unsigned long totalhigh; /* Total high memory size */
671 unsigned long freehigh; /* Available high memory size */
672 unsigned int mem_unit; /* Memory unit size in bytes */
673 char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
674};
675
Nikita Danilovc0398ee2005-10-30 15:03:10 -0800676/* Force a compilation error if condition is true */
Andi Kleen921717a2005-09-13 01:25:13 -0700677#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678
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). */
683#define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
684
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685/* Trap pasters of __FUNCTION__ at compile-time */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686#define __FUNCTION__ (__func__)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687
Christoph Lameter08e0f6a2006-09-27 01:50:06 -0700688/* This helps us to avoid #ifdef CONFIG_NUMA */
689#ifdef CONFIG_NUMA
690#define NUMA_BUILD 1
691#else
692#define NUMA_BUILD 0
693#endif
694
Steven Rostedt29e71ab2008-08-14 15:45:10 -0400695/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
696#ifdef CONFIG_FTRACE_MCOUNT_RECORD
697# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
698#endif
699
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700#endif