thp: remove assumptions on pgtable_t type
[deliverable/linux.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)
a3860c1c 38#define SIZE_MAX (~(size_t)0)
1da177e4
LT
39
40#define STACK_MAGIC 0xdeadbeef
41
44696908
DM
42#define REPEAT_BYTE(x) ((~0ul / 0xff) * (x))
43
a79ff731 44#define ALIGN(x, a) __ALIGN_KERNEL((x), (a))
9f93ff5b 45#define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask))
a83308e6 46#define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
f10db627 47#define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
2ea58144 48
c5e631cf
RR
49#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
50
9b3be9f9
YL
51/*
52 * This looks more complex than it should be. But we need to
53 * get the type for the ~ right in round_down (it needs to be
54 * as wide as the result!), and we want to evaluate the macro
55 * arguments just once each.
56 */
57#define __round_mask(x, y) ((__typeof__(x))((y)-1))
58#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
59#define round_down(x, y) ((x) & ~__round_mask(x, y))
60
4552d5dc 61#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
930631ed 62#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
36a26c69
NB
63#define DIV_ROUND_UP_ULL(ll,d) \
64 ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; })
65
66#if BITS_PER_LONG == 32
67# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
68#else
69# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
70#endif
074e61ec
JM
71
72/* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
b28efd54
EP
73#define roundup(x, y) ( \
74{ \
6070bf35 75 const typeof(y) __y = y; \
b28efd54
EP
76 (((x) + (__y - 1)) / __y) * __y; \
77} \
78)
686a0f3d
EP
79#define rounddown(x, y) ( \
80{ \
81 typeof(x) __x = (x); \
82 __x - (__x % (y)); \
83} \
84)
b6d86d3d
GR
85
86/*
87 * Divide positive or negative dividend by positive divisor and round
88 * to closest integer. Result is undefined for negative divisors.
89 */
9fe06081
DW
90#define DIV_ROUND_CLOSEST(x, divisor)( \
91{ \
b6d86d3d
GR
92 typeof(x) __x = x; \
93 typeof(divisor) __d = divisor; \
263a523d 94 (((typeof(x))-1) > 0 || (__x) > 0) ? \
b6d86d3d
GR
95 (((__x) + ((__d) / 2)) / (__d)) : \
96 (((__x) - ((__d) / 2)) / (__d)); \
9fe06081
DW
97} \
98)
1da177e4 99
9993bc63
SQ
100/*
101 * Multiplies an integer by a fraction, while avoiding unnecessary
102 * overflow or loss of precision.
103 */
104#define mult_frac(x, numer, denom)( \
105{ \
106 typeof(x) quot = (x) / (denom); \
107 typeof(x) rem = (x) % (denom); \
108 (quot * (numer)) + ((rem * (numer)) / (denom)); \
109} \
110)
111
112
ca31e146
EGM
113#define _RET_IP_ (unsigned long)__builtin_return_address(0)
114#define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
115
90c699a9 116#ifdef CONFIG_LBDAF
2da96acd
JA
117# include <asm/div64.h>
118# define sector_div(a, b) do_div(a, b)
119#else
120# define sector_div(n, b)( \
121{ \
122 int _res; \
123 _res = (n) % (b); \
124 (n) /= (b); \
125 _res; \
126} \
127)
128#endif
129
218e180e
AM
130/**
131 * upper_32_bits - return bits 32-63 of a number
132 * @n: the number we're accessing
133 *
134 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
135 * the "right shift count >= width of type" warning when that quantity is
136 * 32-bits.
137 */
138#define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
139
204b885e
JR
140/**
141 * lower_32_bits - return bits 0-31 of a number
142 * @n: the number we're accessing
143 */
144#define lower_32_bits(n) ((u32)(n))
145
1da177e4 146struct completion;
df2e71fb 147struct pt_regs;
148struct user;
1da177e4 149
070cb065
UKK
150#ifdef CONFIG_PREEMPT_VOLUNTARY
151extern int _cond_resched(void);
152# define might_resched() _cond_resched()
153#else
154# define might_resched() do { } while (0)
155#endif
156
d902db1e 157#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
d894837f 158 void __might_sleep(const char *file, int line, int preempt_offset);
1da177e4
LT
159/**
160 * might_sleep - annotation for functions that can sleep
161 *
162 * this macro will print a stack trace if it is executed in an atomic
163 * context (spinlock, irq-handler, ...).
164 *
165 * This is a useful debugging help to be able to catch problems early and not
e20ec991 166 * be bitten later when the calling function happens to sleep when it is not
1da177e4
LT
167 * supposed to.
168 */
f8cbd99b 169# define might_sleep() \
e4aafea2 170 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
1da177e4 171#else
d894837f
SK
172 static inline void __might_sleep(const char *file, int line,
173 int preempt_offset) { }
f8cbd99b 174# define might_sleep() do { might_resched(); } while (0)
1da177e4
LT
175#endif
176
368a5fa1 177#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
f8cbd99b 178
71a90484
AM
179/*
180 * abs() handles unsigned and signed longs, ints, shorts and chars. For all
181 * input types abs() returns a signed long.
182 * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64()
183 * for those.
184 */
185#define abs(x) ({ \
186 long ret; \
187 if (sizeof(x) == sizeof(long)) { \
188 long __x = (x); \
189 ret = (__x < 0) ? -__x : __x; \
190 } else { \
191 int __x = (x); \
192 ret = (__x < 0) ? -__x : __x; \
193 } \
194 ret; \
1da177e4
LT
195 })
196
658716d1
BB
197#define abs64(x) ({ \
198 s64 __x = (x); \
199 (__x < 0) ? -__x : __x; \
200 })
201
3ee1afa3
NP
202#ifdef CONFIG_PROVE_LOCKING
203void might_fault(void);
204#else
205static inline void might_fault(void)
206{
207 might_sleep();
208}
209#endif
210
e041c683 211extern struct atomic_notifier_head panic_notifier_list;
c7ff0d9c 212extern long (*panic_blink)(int state);
9402c95f 213__printf(1, 2)
4da47859 214void panic(const char *fmt, ...)
ff2d8b19 215 __noreturn __cold;
dd287796
AM
216extern void oops_enter(void);
217extern void oops_exit(void);
863a6049 218void print_oops_end_marker(void);
dd287796 219extern int oops_may_print(void);
9402c95f 220void do_exit(long error_code)
ff2d8b19 221 __noreturn;
9402c95f 222void complete_and_exit(struct completion *, long)
ff2d8b19 223 __noreturn;
33ee3b2e
AD
224
225/* Internal, do not use. */
226int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
227int __must_check _kstrtol(const char *s, unsigned int base, long *res);
228
229int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
230int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
231static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
232{
233 /*
234 * We want to shortcut function call, but
235 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
236 */
237 if (sizeof(unsigned long) == sizeof(unsigned long long) &&
238 __alignof__(unsigned long) == __alignof__(unsigned long long))
239 return kstrtoull(s, base, (unsigned long long *)res);
240 else
241 return _kstrtoul(s, base, res);
242}
243
244static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
245{
246 /*
247 * We want to shortcut function call, but
248 * __builtin_types_compatible_p(long, long long) = 0.
249 */
250 if (sizeof(long) == sizeof(long long) &&
251 __alignof__(long) == __alignof__(long long))
252 return kstrtoll(s, base, (long long *)res);
253 else
254 return _kstrtol(s, base, res);
255}
256
257int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
258int __must_check kstrtoint(const char *s, unsigned int base, int *res);
259
260static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
261{
262 return kstrtoull(s, base, res);
263}
264
265static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
266{
267 return kstrtoll(s, base, res);
268}
269
270static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
271{
272 return kstrtouint(s, base, res);
273}
274
275static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
276{
277 return kstrtoint(s, base, res);
278}
279
280int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
281int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
282int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
283int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
284
c196e32a
AD
285int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
286int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
287int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
288int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
289int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
290int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
291int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
292int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
293int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
294int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
295
296static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
297{
298 return kstrtoull_from_user(s, count, base, res);
299}
300
301static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
302{
303 return kstrtoll_from_user(s, count, base, res);
304}
305
306static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
307{
308 return kstrtouint_from_user(s, count, base, res);
309}
310
311static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
312{
313 return kstrtoint_from_user(s, count, base, res);
314}
315
67d0a075
JP
316/* Obsolete, do not use. Use kstrto<foo> instead */
317
1da177e4
LT
318extern unsigned long simple_strtoul(const char *,char **,unsigned int);
319extern long simple_strtol(const char *,char **,unsigned int);
320extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
321extern long long simple_strtoll(const char *,char **,unsigned int);
33ee3b2e
AD
322#define strict_strtoul kstrtoul
323#define strict_strtol kstrtol
324#define strict_strtoull kstrtoull
325#define strict_strtoll kstrtoll
326
1ac101a5
KH
327extern int num_to_str(char *buf, int size, unsigned long long num);
328
67d0a075
JP
329/* lib/printf utilities */
330
b9075fa9
JP
331extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
332extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
333extern __printf(3, 4)
334int snprintf(char *buf, size_t size, const char *fmt, ...);
335extern __printf(3, 0)
336int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
337extern __printf(3, 4)
338int scnprintf(char *buf, size_t size, const char *fmt, ...);
339extern __printf(3, 0)
340int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
341extern __printf(2, 3)
342char *kasprintf(gfp_t gfp, const char *fmt, ...);
11443ec7 343extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
1da177e4 344
6061d949
JP
345extern __scanf(2, 3)
346int sscanf(const char *, const char *, ...);
347extern __scanf(2, 0)
348int vsscanf(const char *, const char *, va_list);
1da177e4
LT
349
350extern int get_option(char **str, int *pint);
351extern char *get_options(const char *str, int nints, int *ints);
d974ae37 352extern unsigned long long memparse(const char *ptr, char **retptr);
1da177e4 353
5e376613 354extern int core_kernel_text(unsigned long addr);
cdbe61bf 355extern int core_kernel_data(unsigned long addr);
1da177e4
LT
356extern int __kernel_text_address(unsigned long addr);
357extern int kernel_text_address(unsigned long addr);
ab7476cf 358extern int func_ptr_is_kernel_text(void *ptr);
ab7476cf 359
04a2e6a5
EB
360struct pid;
361extern struct pid *session_of_pgrp(struct pid *pgrp);
1da177e4 362
1da177e4
LT
363unsigned long int_sqrt(unsigned long);
364
1da177e4 365extern void bust_spinlocks(int yes);
e3e8a75d 366extern void wake_up_klogd(void);
1da177e4 367extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
aa727107 368extern int panic_timeout;
1da177e4 369extern int panic_on_oops;
8da5adda 370extern int panic_on_unrecovered_nmi;
5211a242 371extern int panic_on_io_nmi;
55af7796 372extern int sysctl_panic_on_stackoverflow;
1da177e4 373extern const char *print_tainted(void);
25ddbb18
AK
374extern void add_taint(unsigned flag);
375extern int test_taint(unsigned flag);
376extern unsigned long get_taint(void);
b920de1b 377extern int root_mountflags;
1da177e4 378
2ce802f6
TH
379extern bool early_boot_irqs_disabled;
380
1da177e4
LT
381/* Values used for system_state */
382extern enum system_states {
383 SYSTEM_BOOTING,
384 SYSTEM_RUNNING,
385 SYSTEM_HALT,
386 SYSTEM_POWER_OFF,
387 SYSTEM_RESTART,
388} system_state;
389
25ddbb18
AK
390#define TAINT_PROPRIETARY_MODULE 0
391#define TAINT_FORCED_MODULE 1
392#define TAINT_UNSAFE_SMP 2
393#define TAINT_FORCED_RMMOD 3
394#define TAINT_MACHINE_CHECK 4
395#define TAINT_BAD_PAGE 5
396#define TAINT_USER 6
397#define TAINT_DIE 7
398#define TAINT_OVERRIDDEN_ACPI_TABLE 8
399#define TAINT_WARN 9
26e9a397 400#define TAINT_CRAP 10
92946bc7 401#define TAINT_FIRMWARE_WORKAROUND 11
2449b8ba 402#define TAINT_OOT_MODULE 12
1da177e4 403
3fc95772
HH
404extern const char hex_asc[];
405#define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
406#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
407
55036ba7 408static inline char *hex_byte_pack(char *buf, u8 byte)
3fc95772
HH
409{
410 *buf++ = hex_asc_hi(byte);
411 *buf++ = hex_asc_lo(byte);
412 return buf;
413}
99eaf3c4 414
55036ba7
AS
415static inline char * __deprecated pack_hex_byte(char *buf, u8 byte)
416{
417 return hex_byte_pack(buf, byte);
418}
419
90378889 420extern int hex_to_bin(char ch);
b7804983 421extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
90378889 422
526211bc
IM
423/*
424 * General tracing related utility functions - trace_printk(),
2002c258
SR
425 * tracing_on/tracing_off and tracing_start()/tracing_stop
426 *
427 * Use tracing_on/tracing_off when you want to quickly turn on or off
428 * tracing. It simply enables or disables the recording of the trace events.
156f5a78 429 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
2002c258
SR
430 * file, which gives a means for the kernel and userspace to interact.
431 * Place a tracing_off() in the kernel where you want tracing to end.
432 * From user space, examine the trace, and then echo 1 > tracing_on
433 * to continue tracing.
434 *
435 * tracing_stop/tracing_start has slightly more overhead. It is used
436 * by things like suspend to ram where disabling the recording of the
437 * trace is not enough, but tracing must actually stop because things
438 * like calling smp_processor_id() may crash the system.
439 *
440 * Most likely, you want to use tracing_on/tracing_off.
526211bc 441 */
2002c258 442#ifdef CONFIG_RING_BUFFER
2002c258
SR
443/* trace_off_permanent stops recording with no way to bring it back */
444void tracing_off_permanent(void);
2002c258 445#else
2002c258 446static inline void tracing_off_permanent(void) { }
2002c258 447#endif
cecbca96
FW
448
449enum ftrace_dump_mode {
450 DUMP_NONE,
451 DUMP_ALL,
452 DUMP_ORIG,
453};
454
526211bc 455#ifdef CONFIG_TRACING
93d68e52
SR
456void tracing_on(void);
457void tracing_off(void);
458int tracing_is_on(void);
459
526211bc
IM
460extern void tracing_start(void);
461extern void tracing_stop(void);
462extern void ftrace_off_permanent(void);
463
b9075fa9
JP
464static inline __printf(1, 2)
465void ____trace_printk_check_format(const char *fmt, ...)
769b0441
FW
466{
467}
468#define __trace_printk_check_format(fmt, args...) \
469do { \
470 if (0) \
471 ____trace_printk_check_format(fmt, ##args); \
472} while (0)
473
526211bc
IM
474/**
475 * trace_printk - printf formatting in the ftrace buffer
476 * @fmt: the printf format for printing
477 *
478 * Note: __trace_printk is an internal function for trace_printk and
479 * the @ip is passed in via the trace_printk macro.
480 *
481 * This function allows a kernel developer to debug fast path sections
482 * that printk is not appropriate for. By scattering in various
483 * printk like tracing in the code, a developer can quickly see
484 * where problems are occurring.
485 *
486 * This is intended as a debugging tool for the developer only.
487 * Please refrain from leaving trace_printks scattered around in
488 * your code.
489 */
769b0441
FW
490
491#define trace_printk(fmt, args...) \
492do { \
07d777fe
SR
493 static const char *trace_printk_fmt \
494 __attribute__((section("__trace_printk_fmt"))) = \
495 __builtin_constant_p(fmt) ? fmt : NULL; \
496 \
769b0441 497 __trace_printk_check_format(fmt, ##args); \
48ead020 498 \
07d777fe 499 if (__builtin_constant_p(fmt)) \
48ead020 500 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
07d777fe
SR
501 else \
502 __trace_printk(_THIS_IP_, fmt, ##args); \
769b0441
FW
503} while (0)
504
b9075fa9
JP
505extern __printf(2, 3)
506int __trace_bprintk(unsigned long ip, const char *fmt, ...);
48ead020 507
b9075fa9
JP
508extern __printf(2, 3)
509int __trace_printk(unsigned long ip, const char *fmt, ...);
769b0441 510
03889384
SR
511extern void trace_dump_stack(void);
512
48ead020
FW
513/*
514 * The double __builtin_constant_p is because gcc will give us an error
515 * if we try to allocate the static variable to fmt if it is not a
516 * constant. Even with the outer if statement.
517 */
769b0441
FW
518#define ftrace_vprintk(fmt, vargs) \
519do { \
48ead020
FW
520 if (__builtin_constant_p(fmt)) { \
521 static const char *trace_printk_fmt \
522 __attribute__((section("__trace_printk_fmt"))) = \
523 __builtin_constant_p(fmt) ? fmt : NULL; \
7bffc23e 524 \
48ead020
FW
525 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
526 } else \
527 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
769b0441
FW
528} while (0)
529
48ead020
FW
530extern int
531__ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
532
526211bc
IM
533extern int
534__ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
769b0441 535
cecbca96 536extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
526211bc 537#else
b9075fa9
JP
538static inline __printf(1, 2)
539int trace_printk(const char *fmt, ...);
526211bc
IM
540
541static inline void tracing_start(void) { }
542static inline void tracing_stop(void) { }
543static inline void ftrace_off_permanent(void) { }
e36c5458 544static inline void trace_dump_stack(void) { }
93d68e52
SR
545
546static inline void tracing_on(void) { }
547static inline void tracing_off(void) { }
548static inline int tracing_is_on(void) { return 0; }
549
526211bc
IM
550static inline int
551trace_printk(const char *fmt, ...)
552{
553 return 0;
554}
555static inline int
556ftrace_vprintk(const char *fmt, va_list ap)
557{
558 return 0;
559}
cecbca96 560static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
769b0441 561#endif /* CONFIG_TRACING */
526211bc 562
1da177e4 563/*
bdf4bbaa 564 * min()/max()/clamp() macros that also do
1da177e4
LT
565 * strict type-checking.. See the
566 * "unnecessary" pointer comparison.
567 */
bdf4bbaa
HH
568#define min(x, y) ({ \
569 typeof(x) _min1 = (x); \
570 typeof(y) _min2 = (y); \
571 (void) (&_min1 == &_min2); \
572 _min1 < _min2 ? _min1 : _min2; })
573
574#define max(x, y) ({ \
575 typeof(x) _max1 = (x); \
576 typeof(y) _max2 = (y); \
577 (void) (&_max1 == &_max2); \
578 _max1 > _max2 ? _max1 : _max2; })
579
f27c85c5
HPP
580#define min3(x, y, z) ({ \
581 typeof(x) _min1 = (x); \
582 typeof(y) _min2 = (y); \
583 typeof(z) _min3 = (z); \
584 (void) (&_min1 == &_min2); \
585 (void) (&_min1 == &_min3); \
586 _min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \
587 (_min2 < _min3 ? _min2 : _min3); })
588
589#define max3(x, y, z) ({ \
590 typeof(x) _max1 = (x); \
591 typeof(y) _max2 = (y); \
592 typeof(z) _max3 = (z); \
593 (void) (&_max1 == &_max2); \
594 (void) (&_max1 == &_max3); \
595 _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \
596 (_max2 > _max3 ? _max2 : _max3); })
597
c8bf1336
MP
598/**
599 * min_not_zero - return the minimum that is _not_ zero, unless both are zero
600 * @x: value1
601 * @y: value2
602 */
603#define min_not_zero(x, y) ({ \
604 typeof(x) __x = (x); \
605 typeof(y) __y = (y); \
606 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
607
bdf4bbaa
HH
608/**
609 * clamp - return a value clamped to a given range with strict typechecking
610 * @val: current value
611 * @min: minimum allowable value
612 * @max: maximum allowable value
613 *
614 * This macro does strict typechecking of min/max to make sure they are of the
615 * same type as val. See the unnecessary pointer comparisons.
616 */
617#define clamp(val, min, max) ({ \
618 typeof(val) __val = (val); \
619 typeof(min) __min = (min); \
620 typeof(max) __max = (max); \
621 (void) (&__val == &__min); \
622 (void) (&__val == &__max); \
623 __val = __val < __min ? __min: __val; \
624 __val > __max ? __max: __val; })
1da177e4
LT
625
626/*
627 * ..and if you can't take the strict
628 * types, you can specify one yourself.
629 *
bdf4bbaa
HH
630 * Or not use min/max/clamp at all, of course.
631 */
632#define min_t(type, x, y) ({ \
633 type __min1 = (x); \
634 type __min2 = (y); \
635 __min1 < __min2 ? __min1: __min2; })
636
637#define max_t(type, x, y) ({ \
638 type __max1 = (x); \
639 type __max2 = (y); \
640 __max1 > __max2 ? __max1: __max2; })
641
642/**
643 * clamp_t - return a value clamped to a given range using a given type
644 * @type: the type of variable to use
645 * @val: current value
646 * @min: minimum allowable value
647 * @max: maximum allowable value
648 *
649 * This macro does no typechecking and uses temporary variables of type
650 * 'type' to make all the comparisons.
1da177e4 651 */
bdf4bbaa
HH
652#define clamp_t(type, val, min, max) ({ \
653 type __val = (val); \
654 type __min = (min); \
655 type __max = (max); \
656 __val = __val < __min ? __min: __val; \
657 __val > __max ? __max: __val; })
1da177e4 658
bdf4bbaa
HH
659/**
660 * clamp_val - return a value clamped to a given range using val's type
661 * @val: current value
662 * @min: minimum allowable value
663 * @max: maximum allowable value
664 *
665 * This macro does no typechecking and uses temporary variables of whatever
666 * type the input argument 'val' is. This is useful when val is an unsigned
667 * type and min and max are literals that will otherwise be assigned a signed
668 * integer type.
669 */
670#define clamp_val(val, min, max) ({ \
671 typeof(val) __val = (val); \
672 typeof(val) __min = (min); \
673 typeof(val) __max = (max); \
674 __val = __val < __min ? __min: __val; \
675 __val > __max ? __max: __val; })
1da177e4 676
91f68b73
WF
677
678/*
679 * swap - swap value of @a and @b
680 */
ac7b9004
PZ
681#define swap(a, b) \
682 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
91f68b73 683
1da177e4
LT
684/**
685 * container_of - cast a member of a structure out to the containing structure
1da177e4
LT
686 * @ptr: the pointer to the member.
687 * @type: the type of the container struct this is embedded in.
688 * @member: the name of the member within the struct.
689 *
690 */
691#define container_of(ptr, type, member) ({ \
78db2ad6
DW
692 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
693 (type *)( (char *)__mptr - offsetof(type,member) );})
1da177e4 694
b9d4f426
AL
695/* Trap pasters of __FUNCTION__ at compile-time */
696#define __FUNCTION__ (__func__)
697
698/* This helps us to avoid #ifdef CONFIG_NUMA */
699#ifdef CONFIG_NUMA
700#define NUMA_BUILD 1
701#else
702#define NUMA_BUILD 0
703#endif
704
705/* This helps us avoid #ifdef CONFIG_COMPACTION */
706#ifdef CONFIG_COMPACTION
707#define COMPACTION_BUILD 1
708#else
709#define COMPACTION_BUILD 0
710#endif
711
712/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
713#ifdef CONFIG_FTRACE_MCOUNT_RECORD
714# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
715#endif
9d00f92f 716
9d00f92f
WC
717extern int do_sysinfo(struct sysinfo *info);
718
719#endif /* __KERNEL__ */
720
1da177e4 721#endif
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