blob: cb09238f6d32be355a9b7e2347e48746de7eae77 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_KERNEL_H
2#define _LINUX_KERNEL_H
3
Linus Torvalds1da177e2005-04-16 15:20:36 -07004
5#include <stdarg.h>
6#include <linux/linkage.h>
7#include <linux/stddef.h>
8#include <linux/types.h>
9#include <linux/compiler.h>
10#include <linux/bitops.h>
David Howellsf0d1b0b2006-12-08 02:37:49 -080011#include <linux/log2.h>
Andrew Mortone0deaff42008-07-25 01:45:24 -070012#include <linux/typecheck.h>
Linus Torvalds968ab182010-11-15 13:37:37 -080013#include <linux/printk.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <asm/byteorder.h>
David Howells607ca462012-10-13 10:46:48 +010015#include <uapi/linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016
Alexey Dobriyan4be929b2010-05-24 14:33:03 -070017#define USHRT_MAX ((u16)(~0U))
18#define SHRT_MAX ((s16)(USHRT_MAX>>1))
19#define SHRT_MIN ((s16)(-SHRT_MAX - 1))
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#define INT_MAX ((int)(~0U>>1))
21#define INT_MIN (-INT_MAX - 1)
22#define UINT_MAX (~0U)
23#define LONG_MAX ((long)(~0UL>>1))
24#define LONG_MIN (-LONG_MAX - 1)
25#define ULONG_MAX (~0UL)
OGAWA Hirofumi111ebb62006-06-23 02:03:26 -070026#define LLONG_MAX ((long long)(~0ULL>>1))
27#define LLONG_MIN (-LLONG_MAX - 1)
28#define ULLONG_MAX (~0ULL)
Xi Wanga3860c12012-05-31 16:26:04 -070029#define SIZE_MAX (~(size_t)0)
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
Alex Elder89a07142014-01-23 15:54:00 -080031#define U8_MAX ((u8)~0U)
32#define S8_MAX ((s8)(U8_MAX>>1))
33#define S8_MIN ((s8)(-S8_MAX - 1))
34#define U16_MAX ((u16)~0U)
35#define S16_MAX ((s16)(U16_MAX>>1))
36#define S16_MIN ((s16)(-S16_MAX - 1))
37#define U32_MAX ((u32)~0U)
38#define S32_MAX ((s32)(U32_MAX>>1))
39#define S32_MIN ((s32)(-S32_MAX - 1))
40#define U64_MAX ((u64)~0ULL)
41#define S64_MAX ((s64)(U64_MAX>>1))
42#define S64_MIN ((s64)(-S64_MAX - 1))
43
Linus Torvalds1da177e2005-04-16 15:20:36 -070044#define STACK_MAGIC 0xdeadbeef
45
David S. Miller44696902012-05-23 20:12:50 -070046#define REPEAT_BYTE(x) ((~0ul / 0xff) * (x))
47
zijun_hu3ca45a42016-10-14 15:12:54 +080048/* @a is a power of 2 value */
Alexey Dobriyana79ff732010-04-13 11:21:46 +020049#define ALIGN(x, a) __ALIGN_KERNEL((x), (a))
Alexey Dobriyan9f93ff52010-04-13 14:09:15 +020050#define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask))
Matthew Wilcoxa83308e2007-09-11 15:23:47 -070051#define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
Herbert Xuf10db622008-02-06 01:37:05 -080052#define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
Linus Torvalds2ea58142006-11-26 19:05:22 -080053
Christoph Hellwigd3849952016-11-01 07:40:11 -060054/* generic data direction definitions */
55#define READ 0
56#define WRITE 1
57
Rusty Russellc5e631cf2007-05-06 14:51:05 -070058#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
59
Gustavo Padovan3ed605b2016-04-26 12:32:27 -030060#define u64_to_user_ptr(x) ( \
61{ \
62 typecheck(u64, x); \
63 (void __user *)(uintptr_t)x; \
64} \
65)
66
Yinghai Lu9b3be9f2010-02-10 01:20:29 -080067/*
68 * This looks more complex than it should be. But we need to
69 * get the type for the ~ right in round_down (it needs to be
70 * as wide as the result!), and we want to evaluate the macro
71 * arguments just once each.
72 */
73#define __round_mask(x, y) ((__typeof__(x))((y)-1))
74#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
75#define round_down(x, y) ((x) & ~__round_mask(x, y))
76
Jan Beulich4552d5d2006-06-26 13:57:28 +020077#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
Nicolas Dichtelb5d37552016-03-04 11:52:16 +010078#define DIV_ROUND_UP __KERNEL_DIV_ROUND_UP
Nicholas Bellinger36a26c62011-07-26 00:35:26 -070079#define DIV_ROUND_UP_ULL(ll,d) \
80 ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; })
81
82#if BITS_PER_LONG == 32
83# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
84#else
85# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
86#endif
James Morris074e61e2010-11-10 09:01:31 +110087
88/* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
Eric Parisb28efd52010-10-13 17:50:08 -040089#define roundup(x, y) ( \
90{ \
Tetsuo Handa6070bf32010-11-08 11:20:49 +090091 const typeof(y) __y = y; \
Eric Parisb28efd52010-10-13 17:50:08 -040092 (((x) + (__y - 1)) / __y) * __y; \
93} \
94)
Eric Paris686a0f32010-10-13 17:50:02 -040095#define rounddown(x, y) ( \
96{ \
97 typeof(x) __x = (x); \
98 __x - (__x % (y)); \
99} \
100)
Guenter Roeckb6d86d32012-08-24 17:25:01 -0700101
102/*
103 * Divide positive or negative dividend by positive divisor and round
Guenter Roeckc4e18492012-12-20 15:05:42 -0800104 * to closest integer. Result is undefined for negative divisors and
105 * for negative dividends if the divisor variable type is unsigned.
Guenter Roeckb6d86d32012-08-24 17:25:01 -0700106 */
Darrick J. Wong9fe06082009-01-06 14:40:51 -0800107#define DIV_ROUND_CLOSEST(x, divisor)( \
108{ \
Guenter Roeckb6d86d32012-08-24 17:25:01 -0700109 typeof(x) __x = x; \
110 typeof(divisor) __d = divisor; \
Guenter Roeckc4e18492012-12-20 15:05:42 -0800111 (((typeof(x))-1) > 0 || \
112 ((typeof(divisor))-1) > 0 || (__x) > 0) ? \
Guenter Roeckb6d86d32012-08-24 17:25:01 -0700113 (((__x) + ((__d) / 2)) / (__d)) : \
114 (((__x) - ((__d) / 2)) / (__d)); \
Darrick J. Wong9fe06082009-01-06 14:40:51 -0800115} \
116)
Javi Merinof7660932015-04-16 12:43:45 -0700117/*
118 * Same as above but for u64 dividends. divisor must be a 32-bit
119 * number.
120 */
121#define DIV_ROUND_CLOSEST_ULL(x, divisor)( \
122{ \
123 typeof(divisor) __d = divisor; \
124 unsigned long long _tmp = (x) + (__d) / 2; \
125 do_div(_tmp, __d); \
126 _tmp; \
127} \
128)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129
Salman Qazi9993bc632012-03-09 16:41:01 -0800130/*
131 * Multiplies an integer by a fraction, while avoiding unnecessary
132 * overflow or loss of precision.
133 */
134#define mult_frac(x, numer, denom)( \
135{ \
136 typeof(x) quot = (x) / (denom); \
137 typeof(x) rem = (x) % (denom); \
138 (quot * (numer)) + ((rem * (numer)) / (denom)); \
139} \
140)
141
142
Eduard - Gabriel Munteanuca31e142008-07-05 12:14:23 +0300143#define _RET_IP_ (unsigned long)__builtin_return_address(0)
144#define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
145
Bartlomiej Zolnierkiewicz90c699a2009-06-19 08:08:50 +0200146#ifdef CONFIG_LBDAF
Jens Axboe2da96ac2007-10-12 12:40:38 +0200147# include <asm/div64.h>
148# define sector_div(a, b) do_div(a, b)
149#else
150# define sector_div(n, b)( \
151{ \
152 int _res; \
153 _res = (n) % (b); \
154 (n) /= (b); \
155 _res; \
156} \
157)
158#endif
159
Andrew Morton218e1802007-05-10 03:15:18 -0700160/**
161 * upper_32_bits - return bits 32-63 of a number
162 * @n: the number we're accessing
163 *
164 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
165 * the "right shift count >= width of type" warning when that quantity is
166 * 32-bits.
167 */
168#define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
169
Joerg Roedel204b8852008-07-29 22:33:42 -0700170/**
171 * lower_32_bits - return bits 0-31 of a number
172 * @n: the number we're accessing
173 */
174#define lower_32_bits(n) ((u32)(n))
175
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176struct completion;
akpm@osdl.orgdf2e71f2006-01-09 20:51:37 -0800177struct pt_regs;
178struct user;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179
Uwe Kleine-König070cb062008-08-12 15:08:59 -0700180#ifdef CONFIG_PREEMPT_VOLUNTARY
181extern int _cond_resched(void);
182# define might_resched() _cond_resched()
183#else
184# define might_resched() do { } while (0)
185#endif
186
Frederic Weisbeckerd902db12011-06-08 19:31:56 +0200187#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
Peter Zijlstra34274452014-09-24 10:18:56 +0200188 void ___might_sleep(const char *file, int line, int preempt_offset);
Simon Kagstromd8948372009-12-23 11:08:18 +0100189 void __might_sleep(const char *file, int line, int preempt_offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190/**
191 * might_sleep - annotation for functions that can sleep
192 *
193 * this macro will print a stack trace if it is executed in an atomic
194 * context (spinlock, irq-handler, ...).
195 *
196 * This is a useful debugging help to be able to catch problems early and not
Jim Cromiee20ec992006-11-30 04:46:13 +0100197 * be bitten later when the calling function happens to sleep when it is not
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 * supposed to.
199 */
Ingo Molnarf8cbd992005-06-25 14:57:39 -0700200# define might_sleep() \
Frederic Weisbeckere4aafea2009-07-16 15:44:29 +0200201 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
Linus Torvalds00845eb2015-02-01 12:23:32 -0800202# define sched_annotate_sleep() (current->task_state_change = 0)
Ingo Molnarf8cbd992005-06-25 14:57:39 -0700203#else
Peter Zijlstra34274452014-09-24 10:18:56 +0200204 static inline void ___might_sleep(const char *file, int line,
205 int preempt_offset) { }
Simon Kagstromd8948372009-12-23 11:08:18 +0100206 static inline void __might_sleep(const char *file, int line,
207 int preempt_offset) { }
Ingo Molnarf8cbd992005-06-25 14:57:39 -0700208# define might_sleep() do { might_resched(); } while (0)
Peter Zijlstra1029a2b2014-09-24 10:18:49 +0200209# define sched_annotate_sleep() do { } while (0)
Ingo Molnarf8cbd992005-06-25 14:57:39 -0700210#endif
211
Hua Zhong368a5fa2006-06-23 02:05:42 -0700212#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
Ingo Molnarf8cbd992005-06-25 14:57:39 -0700213
Michal Nazarewiczc8299cb2015-11-09 14:58:10 -0800214/**
215 * abs - return absolute value of an argument
Michal Nazarewicz8f57e4d2016-01-15 16:57:58 -0800216 * @x: the value. If it is unsigned type, it is converted to signed type first.
217 * char is treated as if it was signed (regardless of whether it really is)
218 * but the macro's return type is preserved as char.
Michal Nazarewiczc8299cb2015-11-09 14:58:10 -0800219 *
Michal Nazarewicz8f57e4d2016-01-15 16:57:58 -0800220 * Return: an absolute value of x.
Andrew Morton71a90482011-01-12 16:59:35 -0800221 */
Michal Nazarewicz8f57e4d2016-01-15 16:57:58 -0800222#define abs(x) __abs_choose_expr(x, long long, \
223 __abs_choose_expr(x, long, \
224 __abs_choose_expr(x, int, \
225 __abs_choose_expr(x, short, \
226 __abs_choose_expr(x, char, \
227 __builtin_choose_expr( \
228 __builtin_types_compatible_p(typeof(x), char), \
229 (char)({ signed char __x = (x); __x<0?-__x:__x; }), \
230 ((void)0)))))))
231
232#define __abs_choose_expr(x, type, other) __builtin_choose_expr( \
233 __builtin_types_compatible_p(typeof(x), signed type) || \
234 __builtin_types_compatible_p(typeof(x), unsigned type), \
235 ({ signed type __x = (x); __x < 0 ? -__x : __x; }), other)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236
Daniel Borkmann89770b02014-01-22 02:29:40 +0100237/**
238 * reciprocal_scale - "scale" a value into range [0, ep_ro)
239 * @val: value
240 * @ep_ro: right open interval endpoint
241 *
242 * Perform a "reciprocal multiplication" in order to "scale" a value into
243 * range [0, ep_ro), where the upper interval endpoint is right-open.
244 * This is useful, e.g. for accessing a index of an array containing
245 * ep_ro elements, for example. Think of it as sort of modulus, only that
246 * the result isn't that of modulo. ;) Note that if initial input is a
247 * small value, then result will return 0.
248 *
249 * Return: a result based on val in interval [0, ep_ro).
250 */
251static inline u32 reciprocal_scale(u32 val, u32 ep_ro)
252{
253 return (u32)(((u64) val * ep_ro) >> 32);
254}
255
Axel Lin386e7902013-12-12 17:12:24 -0800256#if defined(CONFIG_MMU) && \
257 (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP))
David Hildenbrand9ec23532015-05-11 17:52:07 +0200258#define might_fault() __might_fault(__FILE__, __LINE__)
259void __might_fault(const char *file, int line);
Nick Piggin3ee1afa2008-09-10 13:37:17 +0200260#else
Michael S. Tsirkin662bbcb2013-05-26 17:32:23 +0300261static inline void might_fault(void) { }
Nick Piggin3ee1afa2008-09-10 13:37:17 +0200262#endif
263
Alan Sterne041c682006-03-27 01:16:30 -0800264extern struct atomic_notifier_head panic_notifier_list;
TAMUKI Shoichic7ff0d92010-08-10 18:03:28 -0700265extern long (*panic_blink)(int state);
Joe Perches9402c952012-01-12 17:17:17 -0800266__printf(1, 2)
Peter Zijlstra9af65282016-09-13 18:37:29 +0200267void panic(const char *fmt, ...) __noreturn __cold;
Hidehiro Kawaiebc41f22016-03-22 14:27:17 -0700268void nmi_panic(struct pt_regs *regs, const char *msg);
Andrew Mortondd287792006-03-23 03:00:57 -0800269extern void oops_enter(void);
270extern void oops_exit(void);
Anton Blanchard863a6042010-08-10 18:03:30 -0700271void print_oops_end_marker(void);
Andrew Mortondd287792006-03-23 03:00:57 -0800272extern int oops_may_print(void);
Peter Zijlstra9af65282016-09-13 18:37:29 +0200273void do_exit(long error_code) __noreturn;
274void complete_and_exit(struct completion *, long) __noreturn;
Alexey Dobriyan33ee3b22011-03-22 16:34:40 -0700275
276/* Internal, do not use. */
277int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
278int __must_check _kstrtol(const char *s, unsigned int base, long *res);
279
280int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
281int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
Eldad Zack4c925d62012-12-17 16:03:04 -0800282
283/**
284 * kstrtoul - convert a string to an unsigned long
285 * @s: The start of the string. The string must be null-terminated, and may also
286 * include a single newline before its terminating null. The first character
287 * may also be a plus sign, but not a minus sign.
288 * @base: The number base to use. The maximum supported base is 16. If base is
289 * given as 0, then the base of the string is automatically detected with the
290 * conventional semantics - If it begins with 0x the number will be parsed as a
291 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
292 * parsed as an octal number. Otherwise it will be parsed as a decimal.
293 * @res: Where to write the result of the conversion on success.
294 *
295 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
296 * Used as a replacement for the obsolete simple_strtoull. Return code must
297 * be checked.
298*/
Alexey Dobriyan33ee3b22011-03-22 16:34:40 -0700299static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
300{
301 /*
302 * We want to shortcut function call, but
303 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
304 */
305 if (sizeof(unsigned long) == sizeof(unsigned long long) &&
306 __alignof__(unsigned long) == __alignof__(unsigned long long))
307 return kstrtoull(s, base, (unsigned long long *)res);
308 else
309 return _kstrtoul(s, base, res);
310}
311
Eldad Zack4c925d62012-12-17 16:03:04 -0800312/**
313 * kstrtol - convert a string to a long
314 * @s: The start of the string. The string must be null-terminated, and may also
315 * include a single newline before its terminating null. The first character
316 * may also be a plus sign or a minus sign.
317 * @base: The number base to use. The maximum supported base is 16. If base is
318 * given as 0, then the base of the string is automatically detected with the
319 * conventional semantics - If it begins with 0x the number will be parsed as a
320 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
321 * parsed as an octal number. Otherwise it will be parsed as a decimal.
322 * @res: Where to write the result of the conversion on success.
323 *
324 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
325 * Used as a replacement for the obsolete simple_strtoull. Return code must
326 * be checked.
327 */
Alexey Dobriyan33ee3b22011-03-22 16:34:40 -0700328static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
329{
330 /*
331 * We want to shortcut function call, but
332 * __builtin_types_compatible_p(long, long long) = 0.
333 */
334 if (sizeof(long) == sizeof(long long) &&
335 __alignof__(long) == __alignof__(long long))
336 return kstrtoll(s, base, (long long *)res);
337 else
338 return _kstrtol(s, base, res);
339}
340
341int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
342int __must_check kstrtoint(const char *s, unsigned int base, int *res);
343
344static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
345{
346 return kstrtoull(s, base, res);
347}
348
349static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
350{
351 return kstrtoll(s, base, res);
352}
353
354static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
355{
356 return kstrtouint(s, base, res);
357}
358
359static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
360{
361 return kstrtoint(s, base, res);
362}
363
364int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
365int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
366int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
367int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
Kees Cookef951592016-03-17 14:22:50 -0700368int __must_check kstrtobool(const char *s, bool *res);
Alexey Dobriyan33ee3b22011-03-22 16:34:40 -0700369
Alexey Dobriyanc196e322011-05-24 17:13:31 -0700370int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
371int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
372int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
373int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
374int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
375int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
376int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
377int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
378int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
379int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
Kees Cookef951592016-03-17 14:22:50 -0700380int __must_check kstrtobool_from_user(const char __user *s, size_t count, bool *res);
Alexey Dobriyanc196e322011-05-24 17:13:31 -0700381
382static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
383{
384 return kstrtoull_from_user(s, count, base, res);
385}
386
387static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
388{
389 return kstrtoll_from_user(s, count, base, res);
390}
391
392static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
393{
394 return kstrtouint_from_user(s, count, base, res);
395}
396
397static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
398{
399 return kstrtoint_from_user(s, count, base, res);
400}
401
Joe Perches67d0a072011-10-31 17:13:10 -0700402/* Obsolete, do not use. Use kstrto<foo> instead */
403
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404extern unsigned long simple_strtoul(const char *,char **,unsigned int);
405extern long simple_strtol(const char *,char **,unsigned int);
406extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
407extern long long simple_strtoll(const char *,char **,unsigned int);
Alexey Dobriyan33ee3b22011-03-22 16:34:40 -0700408
KAMEZAWA Hiroyuki1ac101a2012-03-23 15:02:54 -0700409extern int num_to_str(char *buf, int size, unsigned long long num);
410
Joe Perches67d0a072011-10-31 17:13:10 -0700411/* lib/printf utilities */
412
Joe Perchesb9075fa2011-10-31 17:11:33 -0700413extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
414extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
415extern __printf(3, 4)
416int snprintf(char *buf, size_t size, const char *fmt, ...);
417extern __printf(3, 0)
418int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
419extern __printf(3, 4)
420int scnprintf(char *buf, size_t size, const char *fmt, ...);
421extern __printf(3, 0)
422int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
Rasmus Villemoes48a27052016-05-19 17:10:55 -0700423extern __printf(2, 3) __malloc
Joe Perchesb9075fa2011-10-31 17:11:33 -0700424char *kasprintf(gfp_t gfp, const char *fmt, ...);
Rasmus Villemoes48a27052016-05-19 17:10:55 -0700425extern __printf(2, 0) __malloc
Nicolas Iooss8db14862015-07-17 16:23:42 -0700426char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
Rasmus Villemoes0a9df782015-11-06 16:31:20 -0800427extern __printf(2, 0)
428const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list args);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429
Joe Perches6061d942012-03-23 15:02:16 -0700430extern __scanf(2, 3)
431int sscanf(const char *, const char *, ...);
432extern __scanf(2, 0)
433int vsscanf(const char *, const char *, va_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434
435extern int get_option(char **str, int *pint);
436extern char *get_options(const char *str, int nints, int *ints);
Jeremy Fitzhardinged974ae32008-07-24 16:27:46 -0700437extern unsigned long long memparse(const char *ptr, char **retptr);
Dave Young6ccc72b2014-08-14 17:15:27 +0800438extern bool parse_option_str(const char *str, const char *option);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439
Trent Piepho5e376612006-05-15 09:44:06 -0700440extern int core_kernel_text(unsigned long addr);
Steven Rostedtcdbe61b2011-05-05 21:14:55 -0400441extern int core_kernel_data(unsigned long addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442extern int __kernel_text_address(unsigned long addr);
443extern int kernel_text_address(unsigned long addr);
Arjan van de Venab7476c2008-08-15 15:29:38 -0700444extern int func_ptr_is_kernel_text(void *ptr);
Arjan van de Venab7476c2008-08-15 15:29:38 -0700445
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446unsigned long int_sqrt(unsigned long);
447
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448extern void bust_spinlocks(int yes);
449extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
Adrian Bunkaa727102006-04-10 22:53:59 -0700450extern int panic_timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451extern int panic_on_oops;
Don Zickus8da5add2006-09-26 10:52:27 +0200452extern int panic_on_unrecovered_nmi;
Kurt Garloff5211a242009-06-24 14:32:11 -0700453extern int panic_on_io_nmi;
Prarit Bhargava9e3961a2014-12-10 15:45:50 -0800454extern int panic_on_warn;
Daniel Bristot de Oliveira088e9d22016-06-02 13:51:41 -0300455extern int sysctl_panic_on_rcu_stall;
Mitsuo Hayasaka55af7792011-11-29 15:08:36 +0900456extern int sysctl_panic_on_stackoverflow;
HATAYAMA Daisuke5375b702015-06-30 14:57:46 -0700457
458extern bool crash_kexec_post_notifiers;
459
Jason Baron5800dc32013-11-25 23:23:04 +0000460/*
Hidehiro Kawai1717f202015-12-14 11:19:09 +0100461 * panic_cpu is used for synchronizing panic() and crash_kexec() execution. It
462 * holds a CPU number which is executing panic() currently. A value of
463 * PANIC_CPU_INVALID means no CPU has entered panic() or crash_kexec().
464 */
465extern atomic_t panic_cpu;
466#define PANIC_CPU_INVALID -1
467
468/*
Jason Baron5800dc32013-11-25 23:23:04 +0000469 * Only to be used by arch init code. If the user over-wrote the default
470 * CONFIG_PANIC_TIMEOUT, honor it.
471 */
472static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout)
473{
474 if (panic_timeout == arch_default_timeout)
475 panic_timeout = timeout;
476}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477extern const char *print_tainted(void);
Rusty Russell373d4d02013-01-21 17:17:39 +1030478enum lockdep_ok {
479 LOCKDEP_STILL_OK,
480 LOCKDEP_NOW_UNRELIABLE
481};
482extern void add_taint(unsigned flag, enum lockdep_ok);
Andi Kleen25ddbb12008-10-15 22:01:41 -0700483extern int test_taint(unsigned flag);
484extern unsigned long get_taint(void);
David Howellsb920de12008-02-08 04:19:31 -0800485extern int root_mountflags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486
Tejun Heo2ce802f2011-01-20 12:06:35 +0100487extern bool early_boot_irqs_disabled;
488
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489/* Values used for system_state */
490extern enum system_states {
491 SYSTEM_BOOTING,
492 SYSTEM_RUNNING,
493 SYSTEM_HALT,
494 SYSTEM_POWER_OFF,
495 SYSTEM_RESTART,
496} system_state;
497
Andi Kleen25ddbb12008-10-15 22:01:41 -0700498#define TAINT_PROPRIETARY_MODULE 0
499#define TAINT_FORCED_MODULE 1
Dave Jones8c904872014-02-26 10:49:49 -0500500#define TAINT_CPU_OUT_OF_SPEC 2
Andi Kleen25ddbb12008-10-15 22:01:41 -0700501#define TAINT_FORCED_RMMOD 3
502#define TAINT_MACHINE_CHECK 4
503#define TAINT_BAD_PAGE 5
504#define TAINT_USER 6
505#define TAINT_DIE 7
506#define TAINT_OVERRIDDEN_ACPI_TABLE 8
507#define TAINT_WARN 9
Linus Torvalds26e9a392008-10-17 09:50:12 -0700508#define TAINT_CRAP 10
Ben Hutchings92946bc2010-04-03 19:36:42 +0100509#define TAINT_FIRMWARE_WORKAROUND 11
Ben Hutchings2449b8b2011-10-24 15:12:28 +0200510#define TAINT_OOT_MODULE 12
Mathieu Desnoyers66cc69e2014-03-13 12:11:30 +1030511#define TAINT_UNSIGNED_MODULE 13
Josh Hunt69361ee2014-08-08 14:22:31 -0700512#define TAINT_SOFTLOCKUP 14
Seth Jenningsc5f45462014-12-16 11:58:18 -0600513#define TAINT_LIVEPATCH 15
Petr Mladek7fd83292016-09-21 13:47:22 +0200514#define TAINT_FLAGS_COUNT 16
515
516struct taint_flag {
Larry Finger5eb7c0d2017-01-01 20:25:25 -0600517 char c_true; /* character printed when tainted */
518 char c_false; /* character printed when not tainted */
Petr Mladek7fd83292016-09-21 13:47:22 +0200519 bool module; /* also show as a per-module taint flag */
520};
521
522extern const struct taint_flag taint_flags[TAINT_FLAGS_COUNT];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523
Harvey Harrison3fc95772008-05-14 16:05:49 -0700524extern const char hex_asc[];
525#define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
526#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
527
Andy Shevchenko55036ba2011-10-31 17:12:41 -0700528static inline char *hex_byte_pack(char *buf, u8 byte)
Harvey Harrison3fc95772008-05-14 16:05:49 -0700529{
530 *buf++ = hex_asc_hi(byte);
531 *buf++ = hex_asc_lo(byte);
532 return buf;
533}
Randy Dunlap99eaf3c2007-05-10 22:22:39 -0700534
Andre Naujoksc26d4362013-09-13 19:37:12 +0200535extern const char hex_asc_upper[];
536#define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)]
537#define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4]
538
539static inline char *hex_byte_pack_upper(char *buf, u8 byte)
540{
541 *buf++ = hex_asc_upper_hi(byte);
542 *buf++ = hex_asc_upper_lo(byte);
543 return buf;
544}
545
Andy Shevchenko903788892010-05-24 14:33:23 -0700546extern int hex_to_bin(char ch);
Mimi Zoharb7804982011-09-20 11:23:49 -0400547extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
David Howells53d91c52014-09-16 17:36:01 +0100548extern char *bin2hex(char *dst, const void *src, size_t count);
Andy Shevchenko903788892010-05-24 14:33:23 -0700549
Joe Perchesa69f5ed2014-06-24 11:20:48 -0700550bool mac_pton(const char *s, u8 *mac);
Andy Shevchenko4cd57732013-06-04 19:46:26 +0300551
Joe Perches8a64f332009-12-14 18:00:25 -0800552/*
Ingo Molnar526211b2009-03-05 10:28:45 +0100553 * General tracing related utility functions - trace_printk(),
Steven Rostedt2002c252009-03-05 10:35:56 -0500554 * tracing_on/tracing_off and tracing_start()/tracing_stop
555 *
556 * Use tracing_on/tracing_off when you want to quickly turn on or off
557 * tracing. It simply enables or disables the recording of the trace events.
GeunSik Lim156f5a72009-06-02 15:01:37 +0900558 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
Steven Rostedt2002c252009-03-05 10:35:56 -0500559 * file, which gives a means for the kernel and userspace to interact.
560 * Place a tracing_off() in the kernel where you want tracing to end.
561 * From user space, examine the trace, and then echo 1 > tracing_on
562 * to continue tracing.
563 *
564 * tracing_stop/tracing_start has slightly more overhead. It is used
565 * by things like suspend to ram where disabling the recording of the
566 * trace is not enough, but tracing must actually stop because things
567 * like calling smp_processor_id() may crash the system.
568 *
569 * Most likely, you want to use tracing_on/tracing_off.
Ingo Molnar526211b2009-03-05 10:28:45 +0100570 */
Frederic Weisbeckercecbca92010-04-18 19:08:41 +0200571
572enum ftrace_dump_mode {
573 DUMP_NONE,
574 DUMP_ALL,
575 DUMP_ORIG,
576};
577
Ingo Molnar526211b2009-03-05 10:28:45 +0100578#ifdef CONFIG_TRACING
Steven Rostedt93d68e52012-03-20 12:28:29 -0400579void tracing_on(void);
580void tracing_off(void);
581int tracing_is_on(void);
Steven Rostedt (Red Hat)ad909e22013-03-06 21:45:37 -0500582void tracing_snapshot(void);
583void tracing_snapshot_alloc(void);
Steven Rostedt93d68e52012-03-20 12:28:29 -0400584
Ingo Molnar526211b2009-03-05 10:28:45 +0100585extern void tracing_start(void);
586extern void tracing_stop(void);
Ingo Molnar526211b2009-03-05 10:28:45 +0100587
Joe Perchesb9075fa2011-10-31 17:11:33 -0700588static inline __printf(1, 2)
589void ____trace_printk_check_format(const char *fmt, ...)
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100590{
591}
592#define __trace_printk_check_format(fmt, args...) \
593do { \
594 if (0) \
595 ____trace_printk_check_format(fmt, ##args); \
596} while (0)
597
Ingo Molnar526211b2009-03-05 10:28:45 +0100598/**
599 * trace_printk - printf formatting in the ftrace buffer
600 * @fmt: the printf format for printing
601 *
602 * Note: __trace_printk is an internal function for trace_printk and
603 * the @ip is passed in via the trace_printk macro.
604 *
605 * This function allows a kernel developer to debug fast path sections
606 * that printk is not appropriate for. By scattering in various
607 * printk like tracing in the code, a developer can quickly see
608 * where problems are occurring.
609 *
610 * This is intended as a debugging tool for the developer only.
611 * Please refrain from leaving trace_printks scattered around in
Steven Rostedt (Red Hat)09ae7232013-03-08 21:02:34 -0500612 * your code. (Extra memory is used for special buffers that are
613 * allocated when trace_printk() is used)
Steven Rostedt (Red Hat)9d3c752c2013-03-08 22:11:57 -0500614 *
615 * A little optization trick is done here. If there's only one
616 * argument, there's no need to scan the string for printf formats.
617 * The trace_puts() will suffice. But how can we take advantage of
618 * using trace_puts() when trace_printk() has only one argument?
619 * By stringifying the args and checking the size we can tell
620 * whether or not there are args. __stringify((__VA_ARGS__)) will
621 * turn into "()\0" with a size of 3 when there are no args, anything
622 * else will be bigger. All we need to do is define a string to this,
623 * and then take its size and compare to 3. If it's bigger, use
624 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just
625 * let gcc optimize the rest.
Ingo Molnar526211b2009-03-05 10:28:45 +0100626 */
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100627
Steven Rostedt (Red Hat)9d3c752c2013-03-08 22:11:57 -0500628#define trace_printk(fmt, ...) \
629do { \
630 char _______STR[] = __stringify((__VA_ARGS__)); \
631 if (sizeof(_______STR) > 3) \
632 do_trace_printk(fmt, ##__VA_ARGS__); \
633 else \
634 trace_puts(fmt); \
635} while (0)
636
637#define do_trace_printk(fmt, args...) \
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100638do { \
Steven Rostedt (Red Hat)3debb0a2016-03-22 17:30:58 -0400639 static const char *trace_printk_fmt __used \
Steven Rostedt07d777f2011-09-22 14:01:55 -0400640 __attribute__((section("__trace_printk_fmt"))) = \
641 __builtin_constant_p(fmt) ? fmt : NULL; \
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100642 \
Steven Rostedt07d777f2011-09-22 14:01:55 -0400643 __trace_printk_check_format(fmt, ##args); \
644 \
645 if (__builtin_constant_p(fmt)) \
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100646 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
Steven Rostedt07d777f2011-09-22 14:01:55 -0400647 else \
648 __trace_printk(_THIS_IP_, fmt, ##args); \
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100649} while (0)
650
Joe Perchesb9075fa2011-10-31 17:11:33 -0700651extern __printf(2, 3)
652int __trace_bprintk(unsigned long ip, const char *fmt, ...);
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100653
Joe Perchesb9075fa2011-10-31 17:11:33 -0700654extern __printf(2, 3)
655int __trace_printk(unsigned long ip, const char *fmt, ...);
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100656
Steven Rostedt (Red Hat)09ae7232013-03-08 21:02:34 -0500657/**
658 * trace_puts - write a string into the ftrace buffer
659 * @str: the string to record
660 *
661 * Note: __trace_bputs is an internal function for trace_puts and
662 * the @ip is passed in via the trace_puts macro.
663 *
664 * This is similar to trace_printk() but is made for those really fast
665 * paths that a developer wants the least amount of "Heisenbug" affects,
666 * where the processing of the print format is still too much.
667 *
668 * This function allows a kernel developer to debug fast path sections
669 * that printk is not appropriate for. By scattering in various
670 * printk like tracing in the code, a developer can quickly see
671 * where problems are occurring.
672 *
673 * This is intended as a debugging tool for the developer only.
674 * Please refrain from leaving trace_puts scattered around in
675 * your code. (Extra memory is used for special buffers that are
676 * allocated when trace_puts() is used)
677 *
678 * Returns: 0 if nothing was written, positive # if string was.
679 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used)
680 */
681
Steven Rostedt (Red Hat)09ae7232013-03-08 21:02:34 -0500682#define trace_puts(str) ({ \
Steven Rostedt (Red Hat)3debb0a2016-03-22 17:30:58 -0400683 static const char *trace_printk_fmt __used \
Steven Rostedt (Red Hat)09ae7232013-03-08 21:02:34 -0500684 __attribute__((section("__trace_printk_fmt"))) = \
685 __builtin_constant_p(str) ? str : NULL; \
686 \
687 if (__builtin_constant_p(str)) \
688 __trace_bputs(_THIS_IP_, trace_printk_fmt); \
689 else \
690 __trace_puts(_THIS_IP_, str, strlen(str)); \
691})
Steven Rostedtbcf312c2013-05-02 11:26:13 -0400692extern int __trace_bputs(unsigned long ip, const char *str);
693extern int __trace_puts(unsigned long ip, const char *str, int size);
Steven Rostedt (Red Hat)09ae7232013-03-08 21:02:34 -0500694
Steven Rostedt (Red Hat)c142be82013-03-13 09:55:57 -0400695extern void trace_dump_stack(int skip);
Steven Rostedt03889382009-12-11 09:48:22 -0500696
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100697/*
698 * The double __builtin_constant_p is because gcc will give us an error
699 * if we try to allocate the static variable to fmt if it is not a
700 * constant. Even with the outer if statement.
701 */
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100702#define ftrace_vprintk(fmt, vargs) \
703do { \
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100704 if (__builtin_constant_p(fmt)) { \
Steven Rostedt (Red Hat)3debb0a2016-03-22 17:30:58 -0400705 static const char *trace_printk_fmt __used \
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100706 __attribute__((section("__trace_printk_fmt"))) = \
707 __builtin_constant_p(fmt) ? fmt : NULL; \
Ingo Molnar7bffc232009-03-09 10:11:36 +0100708 \
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100709 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
710 } else \
711 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100712} while (0)
713
Nicolas Iooss8db14862015-07-17 16:23:42 -0700714extern __printf(2, 0) int
Frederic Weisbecker48ead022009-03-12 18:24:49 +0100715__ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
716
Nicolas Iooss8db14862015-07-17 16:23:42 -0700717extern __printf(2, 0) int
Ingo Molnar526211b2009-03-05 10:28:45 +0100718__ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100719
Frederic Weisbeckercecbca92010-04-18 19:08:41 +0200720extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
Ingo Molnar526211b2009-03-05 10:28:45 +0100721#else
Ingo Molnar526211b2009-03-05 10:28:45 +0100722static inline void tracing_start(void) { }
723static inline void tracing_stop(void) { }
Dhaval Gianie67bc512013-08-02 14:47:29 -0400724static inline void trace_dump_stack(int skip) { }
Steven Rostedt93d68e52012-03-20 12:28:29 -0400725
726static inline void tracing_on(void) { }
727static inline void tracing_off(void) { }
728static inline int tracing_is_on(void) { return 0; }
Steven Rostedt (Red Hat)ad909e22013-03-06 21:45:37 -0500729static inline void tracing_snapshot(void) { }
730static inline void tracing_snapshot_alloc(void) { }
Steven Rostedt93d68e52012-03-20 12:28:29 -0400731
Michal Hocko60efc152012-10-25 15:41:51 +0200732static inline __printf(1, 2)
733int trace_printk(const char *fmt, ...)
Ingo Molnar526211b2009-03-05 10:28:45 +0100734{
735 return 0;
736}
Nicolas Iooss8db14862015-07-17 16:23:42 -0700737static __printf(1, 0) inline int
Ingo Molnar526211b2009-03-05 10:28:45 +0100738ftrace_vprintk(const char *fmt, va_list ap)
739{
740 return 0;
741}
Frederic Weisbeckercecbca92010-04-18 19:08:41 +0200742static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
Frederic Weisbecker769b0442009-03-06 17:21:49 +0100743#endif /* CONFIG_TRACING */
Ingo Molnar526211b2009-03-05 10:28:45 +0100744
745/*
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700746 * min()/max()/clamp() macros that also do
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747 * strict type-checking.. See the
748 * "unnecessary" pointer comparison.
749 */
Johannes Berg589a9782016-10-07 17:02:42 -0700750#define __min(t1, t2, min1, min2, x, y) ({ \
751 t1 min1 = (x); \
752 t2 min2 = (y); \
753 (void) (&min1 == &min2); \
754 min1 < min2 ? min1 : min2; })
755#define min(x, y) \
756 __min(typeof(x), typeof(y), \
757 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \
758 x, y)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759
Johannes Berg589a9782016-10-07 17:02:42 -0700760#define __max(t1, t2, max1, max2, x, y) ({ \
761 t1 max1 = (x); \
762 t2 max2 = (y); \
763 (void) (&max1 == &max2); \
764 max1 > max2 ? max1 : max2; })
765#define max(x, y) \
766 __max(typeof(x), typeof(y), \
767 __UNIQUE_ID(max1_), __UNIQUE_ID(max2_), \
768 x, y)
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700769
Michal Nazarewicz2e1d06e2014-10-09 15:30:13 -0700770#define min3(x, y, z) min((typeof(x))min(x, y), z)
771#define max3(x, y, z) max((typeof(x))max(x, y), z)
Hagen Paul Pfeiferf27c85c2010-10-26 14:22:21 -0700772
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700773/**
Martin K. Petersenc8bf1332010-09-10 20:07:38 +0200774 * min_not_zero - return the minimum that is _not_ zero, unless both are zero
775 * @x: value1
776 * @y: value2
777 */
778#define min_not_zero(x, y) ({ \
779 typeof(x) __x = (x); \
780 typeof(y) __y = (y); \
781 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
782
783/**
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700784 * clamp - return a value clamped to a given range with strict typechecking
785 * @val: current value
Michal Nazarewicz2e1d06e2014-10-09 15:30:13 -0700786 * @lo: lowest allowable value
787 * @hi: highest allowable value
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700788 *
Michal Nazarewiczc185b072014-10-09 15:30:15 -0700789 * This macro does strict typechecking of lo/hi to make sure they are of the
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700790 * same type as val. See the unnecessary pointer comparisons.
791 */
Michal Nazarewicz2e1d06e2014-10-09 15:30:13 -0700792#define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793
794/*
795 * ..and if you can't take the strict
796 * types, you can specify one yourself.
797 *
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700798 * Or not use min/max/clamp at all, of course.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799 */
Johannes Berg589a9782016-10-07 17:02:42 -0700800#define min_t(type, x, y) \
801 __min(type, type, \
802 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \
803 x, y)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804
Johannes Berg589a9782016-10-07 17:02:42 -0700805#define max_t(type, x, y) \
806 __max(type, type, \
807 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \
808 x, y)
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700809
810/**
811 * clamp_t - return a value clamped to a given range using a given type
812 * @type: the type of variable to use
813 * @val: current value
Michal Nazarewiczc185b072014-10-09 15:30:15 -0700814 * @lo: minimum allowable value
815 * @hi: maximum allowable value
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700816 *
817 * This macro does no typechecking and uses temporary variables of type
818 * 'type' to make all the comparisons.
819 */
Michal Nazarewiczc185b072014-10-09 15:30:15 -0700820#define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi)
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700821
822/**
823 * clamp_val - return a value clamped to a given range using val's type
824 * @val: current value
Michal Nazarewiczc185b072014-10-09 15:30:15 -0700825 * @lo: minimum allowable value
826 * @hi: maximum allowable value
Harvey Harrisonbdf4bba2008-04-30 00:54:55 -0700827 *
828 * This macro does no typechecking and uses temporary variables of whatever
829 * type the input argument 'val' is. This is useful when val is an unsigned
830 * type and min and max are literals that will otherwise be assigned a signed
831 * integer type.
832 */
Michal Nazarewiczc185b072014-10-09 15:30:15 -0700833#define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834
Wu Fengguang91f68b72009-01-07 18:09:12 -0800835
836/*
837 * swap - swap value of @a and @b
838 */
Peter Zijlstraac7b9002009-02-04 15:11:59 -0800839#define swap(a, b) \
840 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
Wu Fengguang91f68b72009-01-07 18:09:12 -0800841
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842/**
843 * container_of - cast a member of a structure out to the containing structure
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844 * @ptr: the pointer to the member.
845 * @type: the type of the container struct this is embedded in.
846 * @member: the name of the member within the struct.
847 *
848 */
849#define container_of(ptr, type, member) ({ \
Daniel Walker78db2ad2007-05-12 16:28:35 -0700850 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
851 (type *)( (char *)__mptr - offsetof(type,member) );})
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852
Arnaud Lacombeb9d4f422011-07-25 17:13:03 -0700853/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
854#ifdef CONFIG_FTRACE_MCOUNT_RECORD
855# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
856#endif
WANG Cong9d00f922011-07-25 17:13:02 -0700857
Rusty Russell58f86cc2014-03-24 12:00:34 +1030858/* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */
Gobinda Charan Maji28b8d0c2015-05-27 11:09:38 +0930859#define VERIFY_OCTAL_PERMISSIONS(perms) \
860 (BUILD_BUG_ON_ZERO((perms) < 0) + \
861 BUILD_BUG_ON_ZERO((perms) > 0777) + \
862 /* USER_READABLE >= GROUP_READABLE >= OTHER_READABLE */ \
863 BUILD_BUG_ON_ZERO((((perms) >> 6) & 4) < (((perms) >> 3) & 4)) + \
864 BUILD_BUG_ON_ZERO((((perms) >> 3) & 4) < ((perms) & 4)) + \
865 /* USER_WRITABLE >= GROUP_WRITABLE */ \
866 BUILD_BUG_ON_ZERO((((perms) >> 6) & 2) < (((perms) >> 3) & 2)) + \
867 /* OTHER_WRITABLE? Generally considered a bad idea. */ \
868 BUILD_BUG_ON_ZERO((perms) & 2) + \
Rusty Russell58f86cc2014-03-24 12:00:34 +1030869 (perms))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870#endif