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sparc: Increase portability of strncpy_from_user() implementation.
[mirror_ubuntu-bionic-kernel.git] / include / linux / kernel.h
CommitLineData
1da177e4
LT
1#ifndef _LINUX_KERNEL_H
2#define _LINUX_KERNEL_H
3
d8e5ddef
PA
4#include <linux/sysinfo.h>
5
1da177e4
LT
6/*
7 * 'kernel.h' contains some often-used function prototypes etc
8 */
a79ff731
AD
9#define __ALIGN_KERNEL(x, a) __ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
10#define __ALIGN_KERNEL_MASK(x, mask) (((x) + (mask)) & ~(mask))
1da177e4
LT
11
12#ifdef __KERNEL__
13
14#include <stdarg.h>
15#include <linux/linkage.h>
16#include <linux/stddef.h>
17#include <linux/types.h>
18#include <linux/compiler.h>
19#include <linux/bitops.h>
f0d1b0b3 20#include <linux/log2.h>
e0deaff4 21#include <linux/typecheck.h>
968ab183 22#include <linux/printk.h>
e9d376f0 23#include <linux/dynamic_debug.h>
1da177e4 24#include <asm/byteorder.h>
1da177e4 25
4be929be
AD
26#define USHRT_MAX ((u16)(~0U))
27#define SHRT_MAX ((s16)(USHRT_MAX>>1))
28#define SHRT_MIN ((s16)(-SHRT_MAX - 1))
1da177e4
LT
29#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)
111ebb6e
OH
35#define LLONG_MAX ((long long)(~0ULL>>1))
36#define LLONG_MIN (-LLONG_MAX - 1)
37#define ULLONG_MAX (~0ULL)
1da177e4
LT
38
39#define STACK_MAGIC 0xdeadbeef
40
a79ff731 41#define ALIGN(x, a) __ALIGN_KERNEL((x), (a))
9f93ff5b 42#define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask))
a83308e6 43#define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
f10db627 44#define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
2ea58144 45
c5e631cf
RR
46#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
47
9b3be9f9
YL
48/*
49 * This looks more complex than it should be. But we need to
50 * get the type for the ~ right in round_down (it needs to be
51 * as wide as the result!), and we want to evaluate the macro
52 * arguments just once each.
53 */
54#define __round_mask(x, y) ((__typeof__(x))((y)-1))
55#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
56#define round_down(x, y) ((x) & ~__round_mask(x, y))
57
4552d5dc 58#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
930631ed 59#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
36a26c69
NB
60#define DIV_ROUND_UP_ULL(ll,d) \
61 ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; })
62
63#if BITS_PER_LONG == 32
64# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
65#else
66# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
67#endif
074e61ec
JM
68
69/* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
b28efd54
EP
70#define roundup(x, y) ( \
71{ \
6070bf35 72 const typeof(y) __y = y; \
b28efd54
EP
73 (((x) + (__y - 1)) / __y) * __y; \
74} \
75)
686a0f3d
EP
76#define rounddown(x, y) ( \
77{ \
78 typeof(x) __x = (x); \
79 __x - (__x % (y)); \
80} \
81)
9fe06081
DW
82#define DIV_ROUND_CLOSEST(x, divisor)( \
83{ \
84 typeof(divisor) __divisor = divisor; \
85 (((x) + ((__divisor) / 2)) / (__divisor)); \
86} \
87)
1da177e4 88
9993bc63
SQ
89/*
90 * Multiplies an integer by a fraction, while avoiding unnecessary
91 * overflow or loss of precision.
92 */
93#define mult_frac(x, numer, denom)( \
94{ \
95 typeof(x) quot = (x) / (denom); \
96 typeof(x) rem = (x) % (denom); \
97 (quot * (numer)) + ((rem * (numer)) / (denom)); \
98} \
99)
100
101
ca31e146
EGM
102#define _RET_IP_ (unsigned long)__builtin_return_address(0)
103#define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
104
90c699a9 105#ifdef CONFIG_LBDAF
2da96acd
JA
106# include <asm/div64.h>
107# define sector_div(a, b) do_div(a, b)
108#else
109# define sector_div(n, b)( \
110{ \
111 int _res; \
112 _res = (n) % (b); \
113 (n) /= (b); \
114 _res; \
115} \
116)
117#endif
118
218e180e
AM
119/**
120 * upper_32_bits - return bits 32-63 of a number
121 * @n: the number we're accessing
122 *
123 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
124 * the "right shift count >= width of type" warning when that quantity is
125 * 32-bits.
126 */
127#define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
128
204b885e
JR
129/**
130 * lower_32_bits - return bits 0-31 of a number
131 * @n: the number we're accessing
132 */
133#define lower_32_bits(n) ((u32)(n))
134
1da177e4 135struct completion;
df2e71fb 136struct pt_regs;
137struct user;
1da177e4 138
070cb065
UKK
139#ifdef CONFIG_PREEMPT_VOLUNTARY
140extern int _cond_resched(void);
141# define might_resched() _cond_resched()
142#else
143# define might_resched() do { } while (0)
144#endif
145
d902db1e 146#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
d894837f 147 void __might_sleep(const char *file, int line, int preempt_offset);
1da177e4
LT
148/**
149 * might_sleep - annotation for functions that can sleep
150 *
151 * this macro will print a stack trace if it is executed in an atomic
152 * context (spinlock, irq-handler, ...).
153 *
154 * This is a useful debugging help to be able to catch problems early and not
e20ec991 155 * be bitten later when the calling function happens to sleep when it is not
1da177e4
LT
156 * supposed to.
157 */
f8cbd99b 158# define might_sleep() \
e4aafea2 159 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
1da177e4 160#else
d894837f
SK
161 static inline void __might_sleep(const char *file, int line,
162 int preempt_offset) { }
f8cbd99b 163# define might_sleep() do { might_resched(); } while (0)
1da177e4
LT
164#endif
165
368a5fa1 166#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
f8cbd99b 167
71a90484
AM
168/*
169 * abs() handles unsigned and signed longs, ints, shorts and chars. For all
170 * input types abs() returns a signed long.
171 * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64()
172 * for those.
173 */
174#define abs(x) ({ \
175 long ret; \
176 if (sizeof(x) == sizeof(long)) { \
177 long __x = (x); \
178 ret = (__x < 0) ? -__x : __x; \
179 } else { \
180 int __x = (x); \
181 ret = (__x < 0) ? -__x : __x; \
182 } \
183 ret; \
1da177e4
LT
184 })
185
658716d1
BB
186#define abs64(x) ({ \
187 s64 __x = (x); \
188 (__x < 0) ? -__x : __x; \
189 })
190
3ee1afa3
NP
191#ifdef CONFIG_PROVE_LOCKING
192void might_fault(void);
193#else
194static inline void might_fault(void)
195{
196 might_sleep();
197}
198#endif
199
e041c683 200extern struct atomic_notifier_head panic_notifier_list;
c7ff0d9c 201extern long (*panic_blink)(int state);
9402c95f 202__printf(1, 2)
4da47859 203void panic(const char *fmt, ...)
ff2d8b19 204 __noreturn __cold;
dd287796
AM
205extern void oops_enter(void);
206extern void oops_exit(void);
863a6049 207void print_oops_end_marker(void);
dd287796 208extern int oops_may_print(void);
9402c95f 209void do_exit(long error_code)
ff2d8b19 210 __noreturn;
9402c95f 211void complete_and_exit(struct completion *, long)
ff2d8b19 212 __noreturn;
33ee3b2e
AD
213
214/* Internal, do not use. */
215int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
216int __must_check _kstrtol(const char *s, unsigned int base, long *res);
217
218int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
219int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
220static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
221{
222 /*
223 * We want to shortcut function call, but
224 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
225 */
226 if (sizeof(unsigned long) == sizeof(unsigned long long) &&
227 __alignof__(unsigned long) == __alignof__(unsigned long long))
228 return kstrtoull(s, base, (unsigned long long *)res);
229 else
230 return _kstrtoul(s, base, res);
231}
232
233static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
234{
235 /*
236 * We want to shortcut function call, but
237 * __builtin_types_compatible_p(long, long long) = 0.
238 */
239 if (sizeof(long) == sizeof(long long) &&
240 __alignof__(long) == __alignof__(long long))
241 return kstrtoll(s, base, (long long *)res);
242 else
243 return _kstrtol(s, base, res);
244}
245
246int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
247int __must_check kstrtoint(const char *s, unsigned int base, int *res);
248
249static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
250{
251 return kstrtoull(s, base, res);
252}
253
254static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
255{
256 return kstrtoll(s, base, res);
257}
258
259static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
260{
261 return kstrtouint(s, base, res);
262}
263
264static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
265{
266 return kstrtoint(s, base, res);
267}
268
269int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
270int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
271int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
272int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
273
c196e32a
AD
274int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
275int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
276int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
277int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
278int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
279int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
280int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
281int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
282int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
283int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
284
285static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
286{
287 return kstrtoull_from_user(s, count, base, res);
288}
289
290static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
291{
292 return kstrtoll_from_user(s, count, base, res);
293}
294
295static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
296{
297 return kstrtouint_from_user(s, count, base, res);
298}
299
300static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
301{
302 return kstrtoint_from_user(s, count, base, res);
303}
304
67d0a075
JP
305/* Obsolete, do not use. Use kstrto<foo> instead */
306
1da177e4
LT
307extern unsigned long simple_strtoul(const char *,char **,unsigned int);
308extern long simple_strtol(const char *,char **,unsigned int);
309extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
310extern long long simple_strtoll(const char *,char **,unsigned int);
33ee3b2e
AD
311#define strict_strtoul kstrtoul
312#define strict_strtol kstrtol
313#define strict_strtoull kstrtoull
314#define strict_strtoll kstrtoll
315
1ac101a5
KH
316extern int num_to_str(char *buf, int size, unsigned long long num);
317
67d0a075
JP
318/* lib/printf utilities */
319
b9075fa9
JP
320extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
321extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
322extern __printf(3, 4)
323int snprintf(char *buf, size_t size, const char *fmt, ...);
324extern __printf(3, 0)
325int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
326extern __printf(3, 4)
327int scnprintf(char *buf, size_t size, const char *fmt, ...);
328extern __printf(3, 0)
329int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
330extern __printf(2, 3)
331char *kasprintf(gfp_t gfp, const char *fmt, ...);
11443ec7 332extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
1da177e4 333
6061d949
JP
334extern __scanf(2, 3)
335int sscanf(const char *, const char *, ...);
336extern __scanf(2, 0)
337int vsscanf(const char *, const char *, va_list);
1da177e4
LT
338
339extern int get_option(char **str, int *pint);
340extern char *get_options(const char *str, int nints, int *ints);
d974ae37 341extern unsigned long long memparse(const char *ptr, char **retptr);
1da177e4 342
5e376613 343extern int core_kernel_text(unsigned long addr);
cdbe61bf 344extern int core_kernel_data(unsigned long addr);
1da177e4
LT
345extern int __kernel_text_address(unsigned long addr);
346extern int kernel_text_address(unsigned long addr);
ab7476cf 347extern int func_ptr_is_kernel_text(void *ptr);
ab7476cf 348
04a2e6a5
EB
349struct pid;
350extern struct pid *session_of_pgrp(struct pid *pgrp);
1da177e4 351
1da177e4
LT
352unsigned long int_sqrt(unsigned long);
353
1da177e4 354extern void bust_spinlocks(int yes);
e3e8a75d 355extern void wake_up_klogd(void);
1da177e4 356extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
aa727107 357extern int panic_timeout;
1da177e4 358extern int panic_on_oops;
8da5adda 359extern int panic_on_unrecovered_nmi;
5211a242 360extern int panic_on_io_nmi;
55af7796 361extern int sysctl_panic_on_stackoverflow;
1da177e4 362extern const char *print_tainted(void);
25ddbb18
AK
363extern void add_taint(unsigned flag);
364extern int test_taint(unsigned flag);
365extern unsigned long get_taint(void);
b920de1b 366extern int root_mountflags;
1da177e4 367
2ce802f6
TH
368extern bool early_boot_irqs_disabled;
369
1da177e4
LT
370/* Values used for system_state */
371extern enum system_states {
372 SYSTEM_BOOTING,
373 SYSTEM_RUNNING,
374 SYSTEM_HALT,
375 SYSTEM_POWER_OFF,
376 SYSTEM_RESTART,
729b4d4c 377 SYSTEM_SUSPEND_DISK,
1da177e4
LT
378} system_state;
379
25ddbb18
AK
380#define TAINT_PROPRIETARY_MODULE 0
381#define TAINT_FORCED_MODULE 1
382#define TAINT_UNSAFE_SMP 2
383#define TAINT_FORCED_RMMOD 3
384#define TAINT_MACHINE_CHECK 4
385#define TAINT_BAD_PAGE 5
386#define TAINT_USER 6
387#define TAINT_DIE 7
388#define TAINT_OVERRIDDEN_ACPI_TABLE 8
389#define TAINT_WARN 9
26e9a397 390#define TAINT_CRAP 10
92946bc7 391#define TAINT_FIRMWARE_WORKAROUND 11
2449b8ba 392#define TAINT_OOT_MODULE 12
1da177e4 393
3fc95772
HH
394extern const char hex_asc[];
395#define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
396#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
397
55036ba7 398static inline char *hex_byte_pack(char *buf, u8 byte)
3fc95772
HH
399{
400 *buf++ = hex_asc_hi(byte);
401 *buf++ = hex_asc_lo(byte);
402 return buf;
403}
99eaf3c4 404
55036ba7
AS
405static inline char * __deprecated pack_hex_byte(char *buf, u8 byte)
406{
407 return hex_byte_pack(buf, byte);
408}
409
90378889 410extern int hex_to_bin(char ch);
b7804983 411extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
90378889 412
526211bc
IM
413/*
414 * General tracing related utility functions - trace_printk(),
2002c258
SR
415 * tracing_on/tracing_off and tracing_start()/tracing_stop
416 *
417 * Use tracing_on/tracing_off when you want to quickly turn on or off
418 * tracing. It simply enables or disables the recording of the trace events.
156f5a78 419 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
2002c258
SR
420 * file, which gives a means for the kernel and userspace to interact.
421 * Place a tracing_off() in the kernel where you want tracing to end.
422 * From user space, examine the trace, and then echo 1 > tracing_on
423 * to continue tracing.
424 *
425 * tracing_stop/tracing_start has slightly more overhead. It is used
426 * by things like suspend to ram where disabling the recording of the
427 * trace is not enough, but tracing must actually stop because things
428 * like calling smp_processor_id() may crash the system.
429 *
430 * Most likely, you want to use tracing_on/tracing_off.
526211bc 431 */
2002c258 432#ifdef CONFIG_RING_BUFFER
2002c258
SR
433/* trace_off_permanent stops recording with no way to bring it back */
434void tracing_off_permanent(void);
2002c258 435#else
2002c258 436static inline void tracing_off_permanent(void) { }
2002c258 437#endif
cecbca96
FW
438
439enum ftrace_dump_mode {
440 DUMP_NONE,
441 DUMP_ALL,
442 DUMP_ORIG,
443};
444
526211bc 445#ifdef CONFIG_TRACING
93d68e52
SR
446void tracing_on(void);
447void tracing_off(void);
448int tracing_is_on(void);
449
526211bc
IM
450extern void tracing_start(void);
451extern void tracing_stop(void);
452extern void ftrace_off_permanent(void);
453
b9075fa9
JP
454static inline __printf(1, 2)
455void ____trace_printk_check_format(const char *fmt, ...)
769b0441
FW
456{
457}
458#define __trace_printk_check_format(fmt, args...) \
459do { \
460 if (0) \
461 ____trace_printk_check_format(fmt, ##args); \
462} while (0)
463
526211bc
IM
464/**
465 * trace_printk - printf formatting in the ftrace buffer
466 * @fmt: the printf format for printing
467 *
468 * Note: __trace_printk is an internal function for trace_printk and
469 * the @ip is passed in via the trace_printk macro.
470 *
471 * This function allows a kernel developer to debug fast path sections
472 * that printk is not appropriate for. By scattering in various
473 * printk like tracing in the code, a developer can quickly see
474 * where problems are occurring.
475 *
476 * This is intended as a debugging tool for the developer only.
477 * Please refrain from leaving trace_printks scattered around in
478 * your code.
479 */
769b0441
FW
480
481#define trace_printk(fmt, args...) \
482do { \
769b0441 483 __trace_printk_check_format(fmt, ##args); \
48ead020
FW
484 if (__builtin_constant_p(fmt)) { \
485 static const char *trace_printk_fmt \
486 __attribute__((section("__trace_printk_fmt"))) = \
487 __builtin_constant_p(fmt) ? fmt : NULL; \
488 \
489 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
490 } else \
491 __trace_printk(_THIS_IP_, fmt, ##args); \
769b0441
FW
492} while (0)
493
b9075fa9
JP
494extern __printf(2, 3)
495int __trace_bprintk(unsigned long ip, const char *fmt, ...);
48ead020 496
b9075fa9
JP
497extern __printf(2, 3)
498int __trace_printk(unsigned long ip, const char *fmt, ...);
769b0441 499
03889384
SR
500extern void trace_dump_stack(void);
501
48ead020
FW
502/*
503 * The double __builtin_constant_p is because gcc will give us an error
504 * if we try to allocate the static variable to fmt if it is not a
505 * constant. Even with the outer if statement.
506 */
769b0441
FW
507#define ftrace_vprintk(fmt, vargs) \
508do { \
48ead020
FW
509 if (__builtin_constant_p(fmt)) { \
510 static const char *trace_printk_fmt \
511 __attribute__((section("__trace_printk_fmt"))) = \
512 __builtin_constant_p(fmt) ? fmt : NULL; \
7bffc23e 513 \
48ead020
FW
514 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
515 } else \
516 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
769b0441
FW
517} while (0)
518
48ead020
FW
519extern int
520__ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
521
526211bc
IM
522extern int
523__ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
769b0441 524
cecbca96 525extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
526211bc 526#else
b9075fa9
JP
527static inline __printf(1, 2)
528int trace_printk(const char *fmt, ...);
526211bc
IM
529
530static inline void tracing_start(void) { }
531static inline void tracing_stop(void) { }
532static inline void ftrace_off_permanent(void) { }
e36c5458 533static inline void trace_dump_stack(void) { }
93d68e52
SR
534
535static inline void tracing_on(void) { }
536static inline void tracing_off(void) { }
537static inline int tracing_is_on(void) { return 0; }
538
526211bc
IM
539static inline int
540trace_printk(const char *fmt, ...)
541{
542 return 0;
543}
544static inline int
545ftrace_vprintk(const char *fmt, va_list ap)
546{
547 return 0;
548}
cecbca96 549static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
769b0441 550#endif /* CONFIG_TRACING */
526211bc 551
1da177e4 552/*
bdf4bbaa 553 * min()/max()/clamp() macros that also do
1da177e4
LT
554 * strict type-checking.. See the
555 * "unnecessary" pointer comparison.
556 */
bdf4bbaa
HH
557#define min(x, y) ({ \
558 typeof(x) _min1 = (x); \
559 typeof(y) _min2 = (y); \
560 (void) (&_min1 == &_min2); \
561 _min1 < _min2 ? _min1 : _min2; })
562
563#define max(x, y) ({ \
564 typeof(x) _max1 = (x); \
565 typeof(y) _max2 = (y); \
566 (void) (&_max1 == &_max2); \
567 _max1 > _max2 ? _max1 : _max2; })
568
f27c85c5
HPP
569#define min3(x, y, z) ({ \
570 typeof(x) _min1 = (x); \
571 typeof(y) _min2 = (y); \
572 typeof(z) _min3 = (z); \
573 (void) (&_min1 == &_min2); \
574 (void) (&_min1 == &_min3); \
575 _min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \
576 (_min2 < _min3 ? _min2 : _min3); })
577
578#define max3(x, y, z) ({ \
579 typeof(x) _max1 = (x); \
580 typeof(y) _max2 = (y); \
581 typeof(z) _max3 = (z); \
582 (void) (&_max1 == &_max2); \
583 (void) (&_max1 == &_max3); \
584 _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \
585 (_max2 > _max3 ? _max2 : _max3); })
586
c8bf1336
MP
587/**
588 * min_not_zero - return the minimum that is _not_ zero, unless both are zero
589 * @x: value1
590 * @y: value2
591 */
592#define min_not_zero(x, y) ({ \
593 typeof(x) __x = (x); \
594 typeof(y) __y = (y); \
595 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
596
bdf4bbaa
HH
597/**
598 * clamp - return a value clamped to a given range with strict typechecking
599 * @val: current value
600 * @min: minimum allowable value
601 * @max: maximum allowable value
602 *
603 * This macro does strict typechecking of min/max to make sure they are of the
604 * same type as val. See the unnecessary pointer comparisons.
605 */
606#define clamp(val, min, max) ({ \
607 typeof(val) __val = (val); \
608 typeof(min) __min = (min); \
609 typeof(max) __max = (max); \
610 (void) (&__val == &__min); \
611 (void) (&__val == &__max); \
612 __val = __val < __min ? __min: __val; \
613 __val > __max ? __max: __val; })
1da177e4
LT
614
615/*
616 * ..and if you can't take the strict
617 * types, you can specify one yourself.
618 *
bdf4bbaa
HH
619 * Or not use min/max/clamp at all, of course.
620 */
621#define min_t(type, x, y) ({ \
622 type __min1 = (x); \
623 type __min2 = (y); \
624 __min1 < __min2 ? __min1: __min2; })
625
626#define max_t(type, x, y) ({ \
627 type __max1 = (x); \
628 type __max2 = (y); \
629 __max1 > __max2 ? __max1: __max2; })
630
631/**
632 * clamp_t - return a value clamped to a given range using a given type
633 * @type: the type of variable to use
634 * @val: current value
635 * @min: minimum allowable value
636 * @max: maximum allowable value
637 *
638 * This macro does no typechecking and uses temporary variables of type
639 * 'type' to make all the comparisons.
1da177e4 640 */
bdf4bbaa
HH
641#define clamp_t(type, val, min, max) ({ \
642 type __val = (val); \
643 type __min = (min); \
644 type __max = (max); \
645 __val = __val < __min ? __min: __val; \
646 __val > __max ? __max: __val; })
1da177e4 647
bdf4bbaa
HH
648/**
649 * clamp_val - return a value clamped to a given range using val's type
650 * @val: current value
651 * @min: minimum allowable value
652 * @max: maximum allowable value
653 *
654 * This macro does no typechecking and uses temporary variables of whatever
655 * type the input argument 'val' is. This is useful when val is an unsigned
656 * type and min and max are literals that will otherwise be assigned a signed
657 * integer type.
658 */
659#define clamp_val(val, min, max) ({ \
660 typeof(val) __val = (val); \
661 typeof(val) __min = (min); \
662 typeof(val) __max = (max); \
663 __val = __val < __min ? __min: __val; \
664 __val > __max ? __max: __val; })
1da177e4 665
91f68b73
WF
666
667/*
668 * swap - swap value of @a and @b
669 */
ac7b9004
PZ
670#define swap(a, b) \
671 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
91f68b73 672
1da177e4
LT
673/**
674 * container_of - cast a member of a structure out to the containing structure
1da177e4
LT
675 * @ptr: the pointer to the member.
676 * @type: the type of the container struct this is embedded in.
677 * @member: the name of the member within the struct.
678 *
679 */
680#define container_of(ptr, type, member) ({ \
78db2ad6
DW
681 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
682 (type *)( (char *)__mptr - offsetof(type,member) );})
1da177e4 683
b9d4f426
AL
684/* Trap pasters of __FUNCTION__ at compile-time */
685#define __FUNCTION__ (__func__)
686
687/* This helps us to avoid #ifdef CONFIG_NUMA */
688#ifdef CONFIG_NUMA
689#define NUMA_BUILD 1
690#else
691#define NUMA_BUILD 0
692#endif
693
694/* This helps us avoid #ifdef CONFIG_COMPACTION */
695#ifdef CONFIG_COMPACTION
696#define COMPACTION_BUILD 1
697#else
698#define COMPACTION_BUILD 0
699#endif
700
701/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
702#ifdef CONFIG_FTRACE_MCOUNT_RECORD
703# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
704#endif
9d00f92f 705
9d00f92f
WC
706extern int do_sysinfo(struct sysinfo *info);
707
708#endif /* __KERNEL__ */
709
1da177e4 710#endif