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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 Baron346e15b2008-08-12 16:46:19 -040019#include <linux/dynamic_printk.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
Ingo Molnar47492522007-10-16 23:30:29 -0700100/*
101 * Annotation for a "continued" line of log printout (only done after a
102 * line that had no enclosing \n). Only to be used by core/arch code
103 * during early bootup (a continued line is not SMP-safe otherwise).
104 */
105#define KERN_CONT ""
106
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107extern int console_printk[];
108
109#define console_loglevel (console_printk[0])
110#define default_message_loglevel (console_printk[1])
111#define minimum_console_loglevel (console_printk[2])
112#define default_console_loglevel (console_printk[3])
113
114struct completion;
akpm@osdl.orgdf2e71f2006-01-09 20:51:37 -0800115struct pt_regs;
116struct user;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117
Uwe Kleine-König070cb062008-08-12 15:08:59 -0700118#ifdef CONFIG_PREEMPT_VOLUNTARY
119extern int _cond_resched(void);
120# define might_resched() _cond_resched()
121#else
122# define might_resched() do { } while (0)
123#endif
124
Randy Dunlap7106a272008-10-29 14:01:15 -0700125#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
126 void __might_sleep(char *file, int line);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127/**
128 * might_sleep - annotation for functions that can sleep
129 *
130 * this macro will print a stack trace if it is executed in an atomic
131 * context (spinlock, irq-handler, ...).
132 *
133 * This is a useful debugging help to be able to catch problems early and not
Jim Cromiee20ec992006-11-30 04:46:13 +0100134 * be bitten later when the calling function happens to sleep when it is not
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 * supposed to.
136 */
Ingo Molnarf8cbd992005-06-25 14:57:39 -0700137# define might_sleep() \
138 do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
139#else
140# define might_sleep() do { might_resched(); } while (0)
141#endif
142
Hua Zhong368a5fa2006-06-23 02:05:42 -0700143#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
Ingo Molnarf8cbd992005-06-25 14:57:39 -0700144
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145#define abs(x) ({ \
146 int __x = (x); \
147 (__x < 0) ? -__x : __x; \
148 })
149
Nick Piggin3ee1afa2008-09-10 13:37:17 +0200150#ifdef CONFIG_PROVE_LOCKING
151void might_fault(void);
152#else
153static inline void might_fault(void)
154{
155 might_sleep();
156}
157#endif
158
Alan Sterne041c682006-03-27 01:16:30 -0800159extern struct atomic_notifier_head panic_notifier_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160extern long (*panic_blink)(long time);
161NORET_TYPE void panic(const char * fmt, ...)
Andi Kleena586df02007-07-21 17:10:00 +0200162 __attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
Andrew Mortondd287792006-03-23 03:00:57 -0800163extern void oops_enter(void);
164extern void oops_exit(void);
165extern int oops_may_print(void);
Harvey Harrisonec701582008-02-08 04:19:55 -0800166NORET_TYPE void do_exit(long error_code)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 ATTRIB_NORET;
168NORET_TYPE void complete_and_exit(struct completion *, long)
169 ATTRIB_NORET;
170extern unsigned long simple_strtoul(const char *,char **,unsigned int);
171extern long simple_strtol(const char *,char **,unsigned int);
172extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
173extern long long simple_strtoll(const char *,char **,unsigned int);
Yi Yang06b2a762008-02-08 04:21:57 -0800174extern int strict_strtoul(const char *, unsigned int, unsigned long *);
175extern int strict_strtol(const char *, unsigned int, long *);
176extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
177extern int strict_strtoll(const char *, unsigned int, long long *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178extern int sprintf(char * buf, const char * fmt, ...)
179 __attribute__ ((format (printf, 2, 3)));
180extern int vsprintf(char *buf, const char *, va_list)
181 __attribute__ ((format (printf, 2, 0)));
182extern int snprintf(char * buf, size_t size, const char * fmt, ...)
183 __attribute__ ((format (printf, 3, 4)));
184extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
185 __attribute__ ((format (printf, 3, 0)));
186extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
187 __attribute__ ((format (printf, 3, 4)));
188extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
189 __attribute__ ((format (printf, 3, 0)));
Jeremy Fitzhardingee9059142006-06-25 05:49:17 -0700190extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
191 __attribute__ ((format (printf, 2, 3)));
Jeremy Fitzhardinge11443ec2007-04-30 15:09:56 -0700192extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193
194extern int sscanf(const char *, const char *, ...)
195 __attribute__ ((format (scanf, 2, 3)));
196extern int vsscanf(const char *, const char *, va_list)
197 __attribute__ ((format (scanf, 2, 0)));
198
199extern int get_option(char **str, int *pint);
200extern char *get_options(const char *str, int nints, int *ints);
Jeremy Fitzhardinged974ae32008-07-24 16:27:46 -0700201extern unsigned long long memparse(const char *ptr, char **retptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202
Trent Piepho5e376612006-05-15 09:44:06 -0700203extern int core_kernel_text(unsigned long addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204extern int __kernel_text_address(unsigned long addr);
205extern int kernel_text_address(unsigned long addr);
Arjan van de Venab7476c2008-08-15 15:29:38 -0700206extern int func_ptr_is_kernel_text(void *ptr);
Arjan van de Venab7476c2008-08-15 15:29:38 -0700207
Eric W. Biederman04a2e6a2007-02-12 00:52:56 -0800208struct pid;
209extern struct pid *session_of_pgrp(struct pid *pgrp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210
Thomas Renningera0ad05c2008-09-01 14:27:02 +0200211/*
212 * FW_BUG
213 * Add this to a message where you are sure the firmware is buggy or behaves
214 * really stupid or out of spec. Be aware that the responsible BIOS developer
215 * should be able to fix this issue or at least get a concrete idea of the
216 * problem by reading your message without the need of looking at the kernel
217 * code.
218 *
219 * Use it for definite and high priority BIOS bugs.
220 *
221 * FW_WARN
222 * Use it for not that clear (e.g. could the kernel messed up things already?)
223 * and medium priority BIOS bugs.
224 *
225 * FW_INFO
226 * Use this one if you want to tell the user or vendor about something
227 * suspicious, but generally harmless related to the firmware.
228 *
229 * Use it for information or very low priority BIOS bugs.
230 */
231#define FW_BUG "[Firmware Bug]: "
232#define FW_WARN "[Firmware Warn]: "
233#define FW_INFO "[Firmware Info]: "
234
Matt Mackalld59745c2005-05-01 08:59:02 -0700235#ifdef CONFIG_PRINTK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236asmlinkage int vprintk(const char *fmt, va_list args)
237 __attribute__ ((format (printf, 1, 0)));
238asmlinkage int printk(const char * fmt, ...)
Andi Kleena586df02007-07-21 17:10:00 +0200239 __attribute__ ((format (printf, 1, 2))) __cold;
Joe Perches7ef3d2f2008-02-08 04:21:25 -0800240
Dave Young717115e2008-07-25 01:45:58 -0700241extern struct ratelimit_state printk_ratelimit_state;
Joe Perches7ef3d2f2008-02-08 04:21:25 -0800242extern int printk_ratelimit(void);
Joe Perches7ef3d2f2008-02-08 04:21:25 -0800243extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
244 unsigned int interval_msec);
Matt Mackalld59745c2005-05-01 08:59:02 -0700245#else
246static inline int vprintk(const char *s, va_list args)
247 __attribute__ ((format (printf, 1, 0)));
248static inline int vprintk(const char *s, va_list args) { return 0; }
249static inline int printk(const char *s, ...)
250 __attribute__ ((format (printf, 1, 2)));
Andi Kleena586df02007-07-21 17:10:00 +0200251static inline int __cold printk(const char *s, ...) { return 0; }
Joe Perches7ef3d2f2008-02-08 04:21:25 -0800252static inline int printk_ratelimit(void) { return 0; }
Joe Perches7ef3d2f2008-02-08 04:21:25 -0800253static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
254 unsigned int interval_msec) \
255 { return false; }
Matt Mackalld59745c2005-05-01 08:59:02 -0700256#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
Ingo Molnarced9cd42008-08-11 14:38:12 +0200258extern int printk_needs_cpu(int cpu);
259extern void printk_tick(void);
260
Jiri Slabye17ba732008-05-12 15:44:40 +0200261extern void asmlinkage __attribute__((format(printf, 1, 2)))
Ingo Molnar076f9772008-01-30 13:33:06 +0100262 early_printk(const char *fmt, ...);
263
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264unsigned long int_sqrt(unsigned long);
265
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266static inline void console_silent(void)
267{
268 console_loglevel = 0;
269}
270
271static inline void console_verbose(void)
272{
273 if (console_loglevel)
274 console_loglevel = 15;
275}
276
277extern void bust_spinlocks(int yes);
Kirill Korotaeve3e8a752007-02-10 01:46:19 -0800278extern void wake_up_klogd(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
Adrian Bunkaa727102006-04-10 22:53:59 -0700280extern int panic_timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281extern int panic_on_oops;
Don Zickus8da5add2006-09-26 10:52:27 +0200282extern int panic_on_unrecovered_nmi;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283extern const char *print_tainted(void);
Andi Kleen25ddbb12008-10-15 22:01:41 -0700284extern void add_taint(unsigned flag);
285extern int test_taint(unsigned flag);
286extern unsigned long get_taint(void);
David Howellsb920de12008-02-08 04:19:31 -0800287extern int root_mountflags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288
289/* Values used for system_state */
290extern enum system_states {
291 SYSTEM_BOOTING,
292 SYSTEM_RUNNING,
293 SYSTEM_HALT,
294 SYSTEM_POWER_OFF,
295 SYSTEM_RESTART,
Alexey Starikovskiy729b4d42005-12-01 04:29:00 -0500296 SYSTEM_SUSPEND_DISK,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297} system_state;
298
Andi Kleen25ddbb12008-10-15 22:01:41 -0700299#define TAINT_PROPRIETARY_MODULE 0
300#define TAINT_FORCED_MODULE 1
301#define TAINT_UNSAFE_SMP 2
302#define TAINT_FORCED_RMMOD 3
303#define TAINT_MACHINE_CHECK 4
304#define TAINT_BAD_PAGE 5
305#define TAINT_USER 6
306#define TAINT_DIE 7
307#define TAINT_OVERRIDDEN_ACPI_TABLE 8
308#define TAINT_WARN 9
Linus Torvalds26e9a392008-10-17 09:50:12 -0700309#define TAINT_CRAP 10
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310
Andi Kleena586df02007-07-21 17:10:00 +0200311extern void dump_stack(void) __cold;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312
Randy Dunlap99eaf3c2007-05-10 22:22:39 -0700313enum {
314 DUMP_PREFIX_NONE,
315 DUMP_PREFIX_ADDRESS,
316 DUMP_PREFIX_OFFSET
317};
Randy Dunlapc7909232007-06-08 13:47:04 -0700318extern void hex_dump_to_buffer(const void *buf, size_t len,
319 int rowsize, int groupsize,
320 char *linebuf, size_t linebuflen, bool ascii);
321extern void print_hex_dump(const char *level, const char *prefix_str,
322 int prefix_type, int rowsize, int groupsize,
Artem Bityutskiy6a0ed912007-08-07 23:43:14 +0300323 const void *buf, size_t len, bool ascii);
Randy Dunlapc7909232007-06-08 13:47:04 -0700324extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
Alan Sterneb9a9a52007-08-10 13:01:07 -0700325 const void *buf, size_t len);
Harvey Harrison3fc95772008-05-14 16:05:49 -0700326
327extern const char hex_asc[];
328#define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
329#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
330
331static inline char *pack_hex_byte(char *buf, u8 byte)
332{
333 *buf++ = hex_asc_hi(byte);
334 *buf++ = hex_asc_lo(byte);
335 return buf;
336}
Randy Dunlap99eaf3c2007-05-10 22:22:39 -0700337
Martin Schwidefskyd091c2f2008-11-12 21:16:43 +0100338#ifndef pr_fmt
339#define pr_fmt(fmt) fmt
340#endif
341
342#define pr_emerg(fmt, ...) \
343 printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
344#define pr_alert(fmt, ...) \
345 printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
346#define pr_crit(fmt, ...) \
347 printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
348#define pr_err(fmt, ...) \
349 printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
350#define pr_warning(fmt, ...) \
351 printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
352#define pr_notice(fmt, ...) \
353 printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
354#define pr_info(fmt, ...) \
355 printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
Emil Medve1f7c8232007-10-16 23:29:48 -0700356
Pavel Machek1cc6daf2006-08-08 01:37:15 +0200357/* If you are writing a driver, please use dev_dbg instead */
Cornelia Huckd0d85ff2008-12-04 16:55:47 +0100358#if defined(DEBUG)
359#define pr_debug(fmt, ...) \
360 printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
361#elif defined(CONFIG_DYNAMIC_PRINTK_DEBUG)
Jason Baron346e15b2008-08-12 16:46:19 -0400362#define pr_debug(fmt, ...) do { \
Martin Schwidefskyd091c2f2008-11-12 21:16:43 +0100363 dynamic_pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
Jason Baron346e15b2008-08-12 16:46:19 -0400364 } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365#else
Martin Schwidefskyd091c2f2008-11-12 21:16:43 +0100366#define pr_debug(fmt, ...) \
367 ({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368#endif
369
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370/*
371 * Display an IP address in readable format.
372 */
373
374#define NIPQUAD(addr) \
375 ((unsigned char *)&addr)[0], \
376 ((unsigned char *)&addr)[1], \
377 ((unsigned char *)&addr)[2], \
378 ((unsigned char *)&addr)[3]
Joe Perches46b86a22006-01-13 14:29:07 -0800379#define NIPQUAD_FMT "%u.%u.%u.%u"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381#if defined(__LITTLE_ENDIAN)
382#define HIPQUAD(addr) \
383 ((unsigned char *)&addr)[3], \
384 ((unsigned char *)&addr)[2], \
385 ((unsigned char *)&addr)[1], \
386 ((unsigned char *)&addr)[0]
387#elif defined(__BIG_ENDIAN)
388#define HIPQUAD NIPQUAD
389#else
390#error "Please fix asm/byteorder.h"
391#endif /* __LITTLE_ENDIAN */
392
393/*
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700394 * min()/max()/clamp() macros that also do
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 * strict type-checking.. See the
396 * "unnecessary" pointer comparison.
397 */
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700398#define min(x, y) ({ \
399 typeof(x) _min1 = (x); \
400 typeof(y) _min2 = (y); \
401 (void) (&_min1 == &_min2); \
402 _min1 < _min2 ? _min1 : _min2; })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700404#define max(x, y) ({ \
405 typeof(x) _max1 = (x); \
406 typeof(y) _max2 = (y); \
407 (void) (&_max1 == &_max2); \
408 _max1 > _max2 ? _max1 : _max2; })
409
410/**
411 * clamp - return a value clamped to a given range with strict typechecking
412 * @val: current value
413 * @min: minimum allowable value
414 * @max: maximum allowable value
415 *
416 * This macro does strict typechecking of min/max to make sure they are of the
417 * same type as val. See the unnecessary pointer comparisons.
418 */
419#define clamp(val, min, max) ({ \
420 typeof(val) __val = (val); \
421 typeof(min) __min = (min); \
422 typeof(max) __max = (max); \
423 (void) (&__val == &__min); \
424 (void) (&__val == &__max); \
425 __val = __val < __min ? __min: __val; \
426 __val > __max ? __max: __val; })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427
428/*
429 * ..and if you can't take the strict
430 * types, you can specify one yourself.
431 *
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700432 * Or not use min/max/clamp at all, of course.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 */
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700434#define min_t(type, x, y) ({ \
435 type __min1 = (x); \
436 type __min2 = (y); \
437 __min1 < __min2 ? __min1: __min2; })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700439#define max_t(type, x, y) ({ \
440 type __max1 = (x); \
441 type __max2 = (y); \
442 __max1 > __max2 ? __max1: __max2; })
443
444/**
445 * clamp_t - return a value clamped to a given range using a given type
446 * @type: the type of variable to use
447 * @val: current value
448 * @min: minimum allowable value
449 * @max: maximum allowable value
450 *
451 * This macro does no typechecking and uses temporary variables of type
452 * 'type' to make all the comparisons.
453 */
454#define clamp_t(type, val, min, max) ({ \
455 type __val = (val); \
456 type __min = (min); \
457 type __max = (max); \
458 __val = __val < __min ? __min: __val; \
459 __val > __max ? __max: __val; })
460
461/**
462 * clamp_val - return a value clamped to a given range using val's type
463 * @val: current value
464 * @min: minimum allowable value
465 * @max: maximum allowable value
466 *
467 * This macro does no typechecking and uses temporary variables of whatever
468 * type the input argument 'val' is. This is useful when val is an unsigned
469 * type and min and max are literals that will otherwise be assigned a signed
470 * integer type.
471 */
472#define clamp_val(val, min, max) ({ \
473 typeof(val) __val = (val); \
474 typeof(val) __min = (min); \
475 typeof(val) __max = (max); \
476 __val = __val < __min ? __min: __val; \
477 __val > __max ? __max: __val; })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478
Wu Fengguang91f68b72009-01-07 18:09:12 -0800479
480/*
481 * swap - swap value of @a and @b
482 */
Peter Zijlstraac7b9002009-02-04 15:11:59 -0800483#define swap(a, b) \
484 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
Wu Fengguang91f68b72009-01-07 18:09:12 -0800485
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486/**
487 * container_of - cast a member of a structure out to the containing structure
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 * @ptr: the pointer to the member.
489 * @type: the type of the container struct this is embedded in.
490 * @member: the name of the member within the struct.
491 *
492 */
493#define container_of(ptr, type, member) ({ \
Daniel Walker78db2ad2007-05-12 16:28:35 -0700494 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
495 (type *)( (char *)__mptr - offsetof(type,member) );})
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496
Kyle McMartind4d23ad2007-02-10 01:46:00 -0800497struct sysinfo;
498extern int do_sysinfo(struct sysinfo *info);
499
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500#endif /* __KERNEL__ */
501
502#define SI_LOAD_SHIFT 16
503struct sysinfo {
504 long uptime; /* Seconds since boot */
505 unsigned long loads[3]; /* 1, 5, and 15 minute load averages */
506 unsigned long totalram; /* Total usable main memory size */
507 unsigned long freeram; /* Available memory size */
508 unsigned long sharedram; /* Amount of shared memory */
509 unsigned long bufferram; /* Memory used by buffers */
510 unsigned long totalswap; /* Total swap space size */
511 unsigned long freeswap; /* swap space still available */
512 unsigned short procs; /* Number of current processes */
513 unsigned short pad; /* explicit padding for m68k */
514 unsigned long totalhigh; /* Total high memory size */
515 unsigned long freehigh; /* Available high memory size */
516 unsigned int mem_unit; /* Memory unit size in bytes */
517 char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
518};
519
Nikita Danilovc0398ee2005-10-30 15:03:10 -0800520/* Force a compilation error if condition is true */
Andi Kleen921717a2005-09-13 01:25:13 -0700521#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522
Jan Beulich4552d5d2006-06-26 13:57:28 +0200523/* Force a compilation error if condition is true, but also produce a
524 result (of value 0 and type size_t), so the expression can be used
525 e.g. in a structure initializer (or where-ever else comma expressions
526 aren't permitted). */
527#define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
528
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529/* Trap pasters of __FUNCTION__ at compile-time */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530#define __FUNCTION__ (__func__)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531
Christoph Lameter08e0f6a2006-09-27 01:50:06 -0700532/* This helps us to avoid #ifdef CONFIG_NUMA */
533#ifdef CONFIG_NUMA
534#define NUMA_BUILD 1
535#else
536#define NUMA_BUILD 0
537#endif
538
Steven Rostedt29e71ab2008-08-14 15:45:10 -0400539/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
540#ifdef CONFIG_FTRACE_MCOUNT_RECORD
541# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
542#endif
543
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544#endif