fs/ramfs/file-nommu.c: make ramfs_nommu_get_unmapped_area() and ramfs_nommu_mmap...
[deliverable/linux.git] / include / linux / kernel.h
CommitLineData
1da177e4
LT
1#ifndef _LINUX_KERNEL_H
2#define _LINUX_KERNEL_H
3
1da177e4
LT
4
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>
f0d1b0b3 11#include <linux/log2.h>
e0deaff4 12#include <linux/typecheck.h>
968ab183 13#include <linux/printk.h>
e9d376f0 14#include <linux/dynamic_debug.h>
1da177e4 15#include <asm/byteorder.h>
607ca46e 16#include <uapi/linux/kernel.h>
1da177e4 17
4be929be
AD
18#define USHRT_MAX ((u16)(~0U))
19#define SHRT_MAX ((s16)(USHRT_MAX>>1))
20#define SHRT_MIN ((s16)(-SHRT_MAX - 1))
1da177e4
LT
21#define INT_MAX ((int)(~0U>>1))
22#define INT_MIN (-INT_MAX - 1)
23#define UINT_MAX (~0U)
24#define LONG_MAX ((long)(~0UL>>1))
25#define LONG_MIN (-LONG_MAX - 1)
26#define ULONG_MAX (~0UL)
111ebb6e
OH
27#define LLONG_MAX ((long long)(~0ULL>>1))
28#define LLONG_MIN (-LLONG_MAX - 1)
29#define ULLONG_MAX (~0ULL)
a3860c1c 30#define SIZE_MAX (~(size_t)0)
1da177e4 31
89a07141
AE
32#define U8_MAX ((u8)~0U)
33#define S8_MAX ((s8)(U8_MAX>>1))
34#define S8_MIN ((s8)(-S8_MAX - 1))
35#define U16_MAX ((u16)~0U)
36#define S16_MAX ((s16)(U16_MAX>>1))
37#define S16_MIN ((s16)(-S16_MAX - 1))
38#define U32_MAX ((u32)~0U)
39#define S32_MAX ((s32)(U32_MAX>>1))
40#define S32_MIN ((s32)(-S32_MAX - 1))
41#define U64_MAX ((u64)~0ULL)
42#define S64_MAX ((s64)(U64_MAX>>1))
43#define S64_MIN ((s64)(-S64_MAX - 1))
44
1da177e4
LT
45#define STACK_MAGIC 0xdeadbeef
46
44696908
DM
47#define REPEAT_BYTE(x) ((~0ul / 0xff) * (x))
48
a79ff731 49#define ALIGN(x, a) __ALIGN_KERNEL((x), (a))
9f93ff5b 50#define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask))
a83308e6 51#define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
f10db627 52#define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
2ea58144 53
c5e631cf
RR
54#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
55
9b3be9f9
YL
56/*
57 * This looks more complex than it should be. But we need to
58 * get the type for the ~ right in round_down (it needs to be
59 * as wide as the result!), and we want to evaluate the macro
60 * arguments just once each.
61 */
62#define __round_mask(x, y) ((__typeof__(x))((y)-1))
63#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
64#define round_down(x, y) ((x) & ~__round_mask(x, y))
65
4552d5dc 66#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
930631ed 67#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
36a26c69
NB
68#define DIV_ROUND_UP_ULL(ll,d) \
69 ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; })
70
71#if BITS_PER_LONG == 32
72# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
73#else
74# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
75#endif
074e61ec
JM
76
77/* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
b28efd54
EP
78#define roundup(x, y) ( \
79{ \
6070bf35 80 const typeof(y) __y = y; \
b28efd54
EP
81 (((x) + (__y - 1)) / __y) * __y; \
82} \
83)
686a0f3d
EP
84#define rounddown(x, y) ( \
85{ \
86 typeof(x) __x = (x); \
87 __x - (__x % (y)); \
88} \
89)
b6d86d3d
GR
90
91/*
92 * Divide positive or negative dividend by positive divisor and round
c4e18497
GR
93 * to closest integer. Result is undefined for negative divisors and
94 * for negative dividends if the divisor variable type is unsigned.
b6d86d3d 95 */
9fe06081
DW
96#define DIV_ROUND_CLOSEST(x, divisor)( \
97{ \
b6d86d3d
GR
98 typeof(x) __x = x; \
99 typeof(divisor) __d = divisor; \
c4e18497
GR
100 (((typeof(x))-1) > 0 || \
101 ((typeof(divisor))-1) > 0 || (__x) > 0) ? \
b6d86d3d
GR
102 (((__x) + ((__d) / 2)) / (__d)) : \
103 (((__x) - ((__d) / 2)) / (__d)); \
9fe06081
DW
104} \
105)
1da177e4 106
9993bc63
SQ
107/*
108 * Multiplies an integer by a fraction, while avoiding unnecessary
109 * overflow or loss of precision.
110 */
111#define mult_frac(x, numer, denom)( \
112{ \
113 typeof(x) quot = (x) / (denom); \
114 typeof(x) rem = (x) % (denom); \
115 (quot * (numer)) + ((rem * (numer)) / (denom)); \
116} \
117)
118
119
ca31e146
EGM
120#define _RET_IP_ (unsigned long)__builtin_return_address(0)
121#define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
122
90c699a9 123#ifdef CONFIG_LBDAF
2da96acd
JA
124# include <asm/div64.h>
125# define sector_div(a, b) do_div(a, b)
126#else
127# define sector_div(n, b)( \
128{ \
129 int _res; \
130 _res = (n) % (b); \
131 (n) /= (b); \
132 _res; \
133} \
134)
135#endif
136
218e180e
AM
137/**
138 * upper_32_bits - return bits 32-63 of a number
139 * @n: the number we're accessing
140 *
141 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
142 * the "right shift count >= width of type" warning when that quantity is
143 * 32-bits.
144 */
145#define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
146
204b885e
JR
147/**
148 * lower_32_bits - return bits 0-31 of a number
149 * @n: the number we're accessing
150 */
151#define lower_32_bits(n) ((u32)(n))
152
1da177e4 153struct completion;
df2e71fb 154struct pt_regs;
155struct user;
1da177e4 156
070cb065
UKK
157#ifdef CONFIG_PREEMPT_VOLUNTARY
158extern int _cond_resched(void);
159# define might_resched() _cond_resched()
160#else
161# define might_resched() do { } while (0)
162#endif
163
d902db1e 164#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
d894837f 165 void __might_sleep(const char *file, int line, int preempt_offset);
1da177e4
LT
166/**
167 * might_sleep - annotation for functions that can sleep
168 *
169 * this macro will print a stack trace if it is executed in an atomic
170 * context (spinlock, irq-handler, ...).
171 *
172 * This is a useful debugging help to be able to catch problems early and not
e20ec991 173 * be bitten later when the calling function happens to sleep when it is not
1da177e4
LT
174 * supposed to.
175 */
f8cbd99b 176# define might_sleep() \
e4aafea2 177 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
1da177e4 178#else
d894837f
SK
179 static inline void __might_sleep(const char *file, int line,
180 int preempt_offset) { }
f8cbd99b 181# define might_sleep() do { might_resched(); } while (0)
1da177e4
LT
182#endif
183
368a5fa1 184#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
f8cbd99b 185
71a90484
AM
186/*
187 * abs() handles unsigned and signed longs, ints, shorts and chars. For all
188 * input types abs() returns a signed long.
189 * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64()
190 * for those.
191 */
192#define abs(x) ({ \
193 long ret; \
194 if (sizeof(x) == sizeof(long)) { \
195 long __x = (x); \
196 ret = (__x < 0) ? -__x : __x; \
197 } else { \
198 int __x = (x); \
199 ret = (__x < 0) ? -__x : __x; \
200 } \
201 ret; \
1da177e4
LT
202 })
203
658716d1
BB
204#define abs64(x) ({ \
205 s64 __x = (x); \
206 (__x < 0) ? -__x : __x; \
207 })
208
386e7906
AL
209#if defined(CONFIG_MMU) && \
210 (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP))
3ee1afa3
NP
211void might_fault(void);
212#else
662bbcb2 213static inline void might_fault(void) { }
3ee1afa3
NP
214#endif
215
e041c683 216extern struct atomic_notifier_head panic_notifier_list;
c7ff0d9c 217extern long (*panic_blink)(int state);
9402c95f 218__printf(1, 2)
4da47859 219void panic(const char *fmt, ...)
ff2d8b19 220 __noreturn __cold;
dd287796
AM
221extern void oops_enter(void);
222extern void oops_exit(void);
863a6049 223void print_oops_end_marker(void);
dd287796 224extern int oops_may_print(void);
9402c95f 225void do_exit(long error_code)
ff2d8b19 226 __noreturn;
9402c95f 227void complete_and_exit(struct completion *, long)
ff2d8b19 228 __noreturn;
33ee3b2e
AD
229
230/* Internal, do not use. */
231int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
232int __must_check _kstrtol(const char *s, unsigned int base, long *res);
233
234int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
235int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
4c925d60
EZ
236
237/**
238 * kstrtoul - convert a string to an unsigned long
239 * @s: The start of the string. The string must be null-terminated, and may also
240 * include a single newline before its terminating null. The first character
241 * may also be a plus sign, but not a minus sign.
242 * @base: The number base to use. The maximum supported base is 16. If base is
243 * given as 0, then the base of the string is automatically detected with the
244 * conventional semantics - If it begins with 0x the number will be parsed as a
245 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
246 * parsed as an octal number. Otherwise it will be parsed as a decimal.
247 * @res: Where to write the result of the conversion on success.
248 *
249 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
250 * Used as a replacement for the obsolete simple_strtoull. Return code must
251 * be checked.
252*/
33ee3b2e
AD
253static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
254{
255 /*
256 * We want to shortcut function call, but
257 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
258 */
259 if (sizeof(unsigned long) == sizeof(unsigned long long) &&
260 __alignof__(unsigned long) == __alignof__(unsigned long long))
261 return kstrtoull(s, base, (unsigned long long *)res);
262 else
263 return _kstrtoul(s, base, res);
264}
265
4c925d60
EZ
266/**
267 * kstrtol - convert a string to a long
268 * @s: The start of the string. The string must be null-terminated, and may also
269 * include a single newline before its terminating null. The first character
270 * may also be a plus sign or a minus sign.
271 * @base: The number base to use. The maximum supported base is 16. If base is
272 * given as 0, then the base of the string is automatically detected with the
273 * conventional semantics - If it begins with 0x the number will be parsed as a
274 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
275 * parsed as an octal number. Otherwise it will be parsed as a decimal.
276 * @res: Where to write the result of the conversion on success.
277 *
278 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
279 * Used as a replacement for the obsolete simple_strtoull. Return code must
280 * be checked.
281 */
33ee3b2e
AD
282static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
283{
284 /*
285 * We want to shortcut function call, but
286 * __builtin_types_compatible_p(long, long long) = 0.
287 */
288 if (sizeof(long) == sizeof(long long) &&
289 __alignof__(long) == __alignof__(long long))
290 return kstrtoll(s, base, (long long *)res);
291 else
292 return _kstrtol(s, base, res);
293}
294
295int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
296int __must_check kstrtoint(const char *s, unsigned int base, int *res);
297
298static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
299{
300 return kstrtoull(s, base, res);
301}
302
303static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
304{
305 return kstrtoll(s, base, res);
306}
307
308static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
309{
310 return kstrtouint(s, base, res);
311}
312
313static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
314{
315 return kstrtoint(s, base, res);
316}
317
318int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
319int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
320int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
321int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
322
c196e32a
AD
323int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
324int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
325int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
326int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
327int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
328int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
329int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
330int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
331int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
332int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
333
334static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
335{
336 return kstrtoull_from_user(s, count, base, res);
337}
338
339static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
340{
341 return kstrtoll_from_user(s, count, base, res);
342}
343
344static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
345{
346 return kstrtouint_from_user(s, count, base, res);
347}
348
349static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
350{
351 return kstrtoint_from_user(s, count, base, res);
352}
353
67d0a075
JP
354/* Obsolete, do not use. Use kstrto<foo> instead */
355
1da177e4
LT
356extern unsigned long simple_strtoul(const char *,char **,unsigned int);
357extern long simple_strtol(const char *,char **,unsigned int);
358extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
359extern long long simple_strtoll(const char *,char **,unsigned int);
33ee3b2e
AD
360#define strict_strtoul kstrtoul
361#define strict_strtol kstrtol
362#define strict_strtoull kstrtoull
363#define strict_strtoll kstrtoll
364
1ac101a5
KH
365extern int num_to_str(char *buf, int size, unsigned long long num);
366
67d0a075
JP
367/* lib/printf utilities */
368
b9075fa9
JP
369extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
370extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
371extern __printf(3, 4)
372int snprintf(char *buf, size_t size, const char *fmt, ...);
373extern __printf(3, 0)
374int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
375extern __printf(3, 4)
376int scnprintf(char *buf, size_t size, const char *fmt, ...);
377extern __printf(3, 0)
378int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
379extern __printf(2, 3)
380char *kasprintf(gfp_t gfp, const char *fmt, ...);
11443ec7 381extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
1da177e4 382
6061d949
JP
383extern __scanf(2, 3)
384int sscanf(const char *, const char *, ...);
385extern __scanf(2, 0)
386int vsscanf(const char *, const char *, va_list);
1da177e4
LT
387
388extern int get_option(char **str, int *pint);
389extern char *get_options(const char *str, int nints, int *ints);
d974ae37 390extern unsigned long long memparse(const char *ptr, char **retptr);
1da177e4 391
5e376613 392extern int core_kernel_text(unsigned long addr);
cdbe61bf 393extern int core_kernel_data(unsigned long addr);
1da177e4
LT
394extern int __kernel_text_address(unsigned long addr);
395extern int kernel_text_address(unsigned long addr);
ab7476cf 396extern int func_ptr_is_kernel_text(void *ptr);
ab7476cf 397
04a2e6a5
EB
398struct pid;
399extern struct pid *session_of_pgrp(struct pid *pgrp);
1da177e4 400
1da177e4
LT
401unsigned long int_sqrt(unsigned long);
402
1da177e4
LT
403extern void bust_spinlocks(int yes);
404extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
aa727107 405extern int panic_timeout;
1da177e4 406extern int panic_on_oops;
8da5adda 407extern int panic_on_unrecovered_nmi;
5211a242 408extern int panic_on_io_nmi;
55af7796 409extern int sysctl_panic_on_stackoverflow;
5800dc3c
JB
410/*
411 * Only to be used by arch init code. If the user over-wrote the default
412 * CONFIG_PANIC_TIMEOUT, honor it.
413 */
414static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout)
415{
416 if (panic_timeout == arch_default_timeout)
417 panic_timeout = timeout;
418}
1da177e4 419extern const char *print_tainted(void);
373d4d09
RR
420enum lockdep_ok {
421 LOCKDEP_STILL_OK,
422 LOCKDEP_NOW_UNRELIABLE
423};
424extern void add_taint(unsigned flag, enum lockdep_ok);
25ddbb18
AK
425extern int test_taint(unsigned flag);
426extern unsigned long get_taint(void);
b920de1b 427extern int root_mountflags;
1da177e4 428
2ce802f6
TH
429extern bool early_boot_irqs_disabled;
430
1da177e4
LT
431/* Values used for system_state */
432extern enum system_states {
433 SYSTEM_BOOTING,
434 SYSTEM_RUNNING,
435 SYSTEM_HALT,
436 SYSTEM_POWER_OFF,
437 SYSTEM_RESTART,
438} system_state;
439
25ddbb18
AK
440#define TAINT_PROPRIETARY_MODULE 0
441#define TAINT_FORCED_MODULE 1
442#define TAINT_UNSAFE_SMP 2
443#define TAINT_FORCED_RMMOD 3
444#define TAINT_MACHINE_CHECK 4
445#define TAINT_BAD_PAGE 5
446#define TAINT_USER 6
447#define TAINT_DIE 7
448#define TAINT_OVERRIDDEN_ACPI_TABLE 8
449#define TAINT_WARN 9
26e9a397 450#define TAINT_CRAP 10
92946bc7 451#define TAINT_FIRMWARE_WORKAROUND 11
2449b8ba 452#define TAINT_OOT_MODULE 12
1da177e4 453
3fc95772
HH
454extern const char hex_asc[];
455#define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
456#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
457
55036ba7 458static inline char *hex_byte_pack(char *buf, u8 byte)
3fc95772
HH
459{
460 *buf++ = hex_asc_hi(byte);
461 *buf++ = hex_asc_lo(byte);
462 return buf;
463}
99eaf3c4 464
c26d436c
AN
465extern const char hex_asc_upper[];
466#define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)]
467#define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4]
468
469static inline char *hex_byte_pack_upper(char *buf, u8 byte)
470{
471 *buf++ = hex_asc_upper_hi(byte);
472 *buf++ = hex_asc_upper_lo(byte);
473 return buf;
474}
475
55036ba7
AS
476static inline char * __deprecated pack_hex_byte(char *buf, u8 byte)
477{
478 return hex_byte_pack(buf, byte);
479}
480
90378889 481extern int hex_to_bin(char ch);
b7804983 482extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
90378889 483
4cd5773a
AS
484int mac_pton(const char *s, u8 *mac);
485
526211bc
IM
486/*
487 * General tracing related utility functions - trace_printk(),
2002c258
SR
488 * tracing_on/tracing_off and tracing_start()/tracing_stop
489 *
490 * Use tracing_on/tracing_off when you want to quickly turn on or off
491 * tracing. It simply enables or disables the recording of the trace events.
156f5a78 492 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
2002c258
SR
493 * file, which gives a means for the kernel and userspace to interact.
494 * Place a tracing_off() in the kernel where you want tracing to end.
495 * From user space, examine the trace, and then echo 1 > tracing_on
496 * to continue tracing.
497 *
498 * tracing_stop/tracing_start has slightly more overhead. It is used
499 * by things like suspend to ram where disabling the recording of the
500 * trace is not enough, but tracing must actually stop because things
501 * like calling smp_processor_id() may crash the system.
502 *
503 * Most likely, you want to use tracing_on/tracing_off.
526211bc 504 */
2002c258 505#ifdef CONFIG_RING_BUFFER
2002c258
SR
506/* trace_off_permanent stops recording with no way to bring it back */
507void tracing_off_permanent(void);
2002c258 508#else
2002c258 509static inline void tracing_off_permanent(void) { }
2002c258 510#endif
cecbca96
FW
511
512enum ftrace_dump_mode {
513 DUMP_NONE,
514 DUMP_ALL,
515 DUMP_ORIG,
516};
517
526211bc 518#ifdef CONFIG_TRACING
93d68e52
SR
519void tracing_on(void);
520void tracing_off(void);
521int tracing_is_on(void);
ad909e21
SRRH
522void tracing_snapshot(void);
523void tracing_snapshot_alloc(void);
93d68e52 524
526211bc
IM
525extern void tracing_start(void);
526extern void tracing_stop(void);
526211bc 527
b9075fa9
JP
528static inline __printf(1, 2)
529void ____trace_printk_check_format(const char *fmt, ...)
769b0441
FW
530{
531}
532#define __trace_printk_check_format(fmt, args...) \
533do { \
534 if (0) \
535 ____trace_printk_check_format(fmt, ##args); \
536} while (0)
537
526211bc
IM
538/**
539 * trace_printk - printf formatting in the ftrace buffer
540 * @fmt: the printf format for printing
541 *
542 * Note: __trace_printk is an internal function for trace_printk and
543 * the @ip is passed in via the trace_printk macro.
544 *
545 * This function allows a kernel developer to debug fast path sections
546 * that printk is not appropriate for. By scattering in various
547 * printk like tracing in the code, a developer can quickly see
548 * where problems are occurring.
549 *
550 * This is intended as a debugging tool for the developer only.
551 * Please refrain from leaving trace_printks scattered around in
09ae7234
SRRH
552 * your code. (Extra memory is used for special buffers that are
553 * allocated when trace_printk() is used)
9d3c752c
SRRH
554 *
555 * A little optization trick is done here. If there's only one
556 * argument, there's no need to scan the string for printf formats.
557 * The trace_puts() will suffice. But how can we take advantage of
558 * using trace_puts() when trace_printk() has only one argument?
559 * By stringifying the args and checking the size we can tell
560 * whether or not there are args. __stringify((__VA_ARGS__)) will
561 * turn into "()\0" with a size of 3 when there are no args, anything
562 * else will be bigger. All we need to do is define a string to this,
563 * and then take its size and compare to 3. If it's bigger, use
564 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just
565 * let gcc optimize the rest.
526211bc 566 */
769b0441 567
9d3c752c
SRRH
568#define trace_printk(fmt, ...) \
569do { \
570 char _______STR[] = __stringify((__VA_ARGS__)); \
571 if (sizeof(_______STR) > 3) \
572 do_trace_printk(fmt, ##__VA_ARGS__); \
573 else \
574 trace_puts(fmt); \
575} while (0)
576
577#define do_trace_printk(fmt, args...) \
769b0441 578do { \
07d777fe
SR
579 static const char *trace_printk_fmt \
580 __attribute__((section("__trace_printk_fmt"))) = \
581 __builtin_constant_p(fmt) ? fmt : NULL; \
582 \
769b0441 583 __trace_printk_check_format(fmt, ##args); \
48ead020 584 \
07d777fe 585 if (__builtin_constant_p(fmt)) \
48ead020 586 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
07d777fe
SR
587 else \
588 __trace_printk(_THIS_IP_, fmt, ##args); \
769b0441
FW
589} while (0)
590
b9075fa9
JP
591extern __printf(2, 3)
592int __trace_bprintk(unsigned long ip, const char *fmt, ...);
48ead020 593
b9075fa9
JP
594extern __printf(2, 3)
595int __trace_printk(unsigned long ip, const char *fmt, ...);
769b0441 596
09ae7234
SRRH
597/**
598 * trace_puts - write a string into the ftrace buffer
599 * @str: the string to record
600 *
601 * Note: __trace_bputs is an internal function for trace_puts and
602 * the @ip is passed in via the trace_puts macro.
603 *
604 * This is similar to trace_printk() but is made for those really fast
605 * paths that a developer wants the least amount of "Heisenbug" affects,
606 * where the processing of the print format is still too much.
607 *
608 * This function allows a kernel developer to debug fast path sections
609 * that printk is not appropriate for. By scattering in various
610 * printk like tracing in the code, a developer can quickly see
611 * where problems are occurring.
612 *
613 * This is intended as a debugging tool for the developer only.
614 * Please refrain from leaving trace_puts scattered around in
615 * your code. (Extra memory is used for special buffers that are
616 * allocated when trace_puts() is used)
617 *
618 * Returns: 0 if nothing was written, positive # if string was.
619 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used)
620 */
621
09ae7234
SRRH
622#define trace_puts(str) ({ \
623 static const char *trace_printk_fmt \
624 __attribute__((section("__trace_printk_fmt"))) = \
625 __builtin_constant_p(str) ? str : NULL; \
626 \
627 if (__builtin_constant_p(str)) \
628 __trace_bputs(_THIS_IP_, trace_printk_fmt); \
629 else \
630 __trace_puts(_THIS_IP_, str, strlen(str)); \
631})
bcf312cf
SR
632extern int __trace_bputs(unsigned long ip, const char *str);
633extern int __trace_puts(unsigned long ip, const char *str, int size);
09ae7234 634
c142be8e 635extern void trace_dump_stack(int skip);
03889384 636
48ead020
FW
637/*
638 * The double __builtin_constant_p is because gcc will give us an error
639 * if we try to allocate the static variable to fmt if it is not a
640 * constant. Even with the outer if statement.
641 */
769b0441
FW
642#define ftrace_vprintk(fmt, vargs) \
643do { \
48ead020
FW
644 if (__builtin_constant_p(fmt)) { \
645 static const char *trace_printk_fmt \
646 __attribute__((section("__trace_printk_fmt"))) = \
647 __builtin_constant_p(fmt) ? fmt : NULL; \
7bffc23e 648 \
48ead020
FW
649 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
650 } else \
651 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
769b0441
FW
652} while (0)
653
48ead020
FW
654extern int
655__ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
656
526211bc
IM
657extern int
658__ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
769b0441 659
cecbca96 660extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
526211bc 661#else
526211bc
IM
662static inline void tracing_start(void) { }
663static inline void tracing_stop(void) { }
e67bc51e 664static inline void trace_dump_stack(int skip) { }
93d68e52
SR
665
666static inline void tracing_on(void) { }
667static inline void tracing_off(void) { }
668static inline int tracing_is_on(void) { return 0; }
ad909e21
SRRH
669static inline void tracing_snapshot(void) { }
670static inline void tracing_snapshot_alloc(void) { }
93d68e52 671
60efc15a
MH
672static inline __printf(1, 2)
673int trace_printk(const char *fmt, ...)
526211bc
IM
674{
675 return 0;
676}
677static inline int
678ftrace_vprintk(const char *fmt, va_list ap)
679{
680 return 0;
681}
cecbca96 682static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
769b0441 683#endif /* CONFIG_TRACING */
526211bc 684
1da177e4 685/*
bdf4bbaa 686 * min()/max()/clamp() macros that also do
1da177e4
LT
687 * strict type-checking.. See the
688 * "unnecessary" pointer comparison.
689 */
bdf4bbaa
HH
690#define min(x, y) ({ \
691 typeof(x) _min1 = (x); \
692 typeof(y) _min2 = (y); \
693 (void) (&_min1 == &_min2); \
694 _min1 < _min2 ? _min1 : _min2; })
695
696#define max(x, y) ({ \
697 typeof(x) _max1 = (x); \
698 typeof(y) _max2 = (y); \
699 (void) (&_max1 == &_max2); \
700 _max1 > _max2 ? _max1 : _max2; })
701
f27c85c5
HPP
702#define min3(x, y, z) ({ \
703 typeof(x) _min1 = (x); \
704 typeof(y) _min2 = (y); \
705 typeof(z) _min3 = (z); \
706 (void) (&_min1 == &_min2); \
707 (void) (&_min1 == &_min3); \
708 _min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \
709 (_min2 < _min3 ? _min2 : _min3); })
710
711#define max3(x, y, z) ({ \
712 typeof(x) _max1 = (x); \
713 typeof(y) _max2 = (y); \
714 typeof(z) _max3 = (z); \
715 (void) (&_max1 == &_max2); \
716 (void) (&_max1 == &_max3); \
717 _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \
718 (_max2 > _max3 ? _max2 : _max3); })
719
c8bf1336
MP
720/**
721 * min_not_zero - return the minimum that is _not_ zero, unless both are zero
722 * @x: value1
723 * @y: value2
724 */
725#define min_not_zero(x, y) ({ \
726 typeof(x) __x = (x); \
727 typeof(y) __y = (y); \
728 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
729
bdf4bbaa
HH
730/**
731 * clamp - return a value clamped to a given range with strict typechecking
732 * @val: current value
733 * @min: minimum allowable value
734 * @max: maximum allowable value
735 *
736 * This macro does strict typechecking of min/max to make sure they are of the
737 * same type as val. See the unnecessary pointer comparisons.
738 */
739#define clamp(val, min, max) ({ \
740 typeof(val) __val = (val); \
741 typeof(min) __min = (min); \
742 typeof(max) __max = (max); \
743 (void) (&__val == &__min); \
744 (void) (&__val == &__max); \
745 __val = __val < __min ? __min: __val; \
746 __val > __max ? __max: __val; })
1da177e4
LT
747
748/*
749 * ..and if you can't take the strict
750 * types, you can specify one yourself.
751 *
bdf4bbaa
HH
752 * Or not use min/max/clamp at all, of course.
753 */
754#define min_t(type, x, y) ({ \
755 type __min1 = (x); \
756 type __min2 = (y); \
757 __min1 < __min2 ? __min1: __min2; })
758
759#define max_t(type, x, y) ({ \
760 type __max1 = (x); \
761 type __max2 = (y); \
762 __max1 > __max2 ? __max1: __max2; })
763
764/**
765 * clamp_t - return a value clamped to a given range using a given type
766 * @type: the type of variable to use
767 * @val: current value
768 * @min: minimum allowable value
769 * @max: maximum allowable value
770 *
771 * This macro does no typechecking and uses temporary variables of type
772 * 'type' to make all the comparisons.
1da177e4 773 */
bdf4bbaa
HH
774#define clamp_t(type, val, min, max) ({ \
775 type __val = (val); \
776 type __min = (min); \
777 type __max = (max); \
778 __val = __val < __min ? __min: __val; \
779 __val > __max ? __max: __val; })
1da177e4 780
bdf4bbaa
HH
781/**
782 * clamp_val - return a value clamped to a given range using val's type
783 * @val: current value
784 * @min: minimum allowable value
785 * @max: maximum allowable value
786 *
787 * This macro does no typechecking and uses temporary variables of whatever
788 * type the input argument 'val' is. This is useful when val is an unsigned
789 * type and min and max are literals that will otherwise be assigned a signed
790 * integer type.
791 */
792#define clamp_val(val, min, max) ({ \
793 typeof(val) __val = (val); \
794 typeof(val) __min = (min); \
795 typeof(val) __max = (max); \
796 __val = __val < __min ? __min: __val; \
797 __val > __max ? __max: __val; })
1da177e4 798
91f68b73
WF
799
800/*
801 * swap - swap value of @a and @b
802 */
ac7b9004
PZ
803#define swap(a, b) \
804 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
91f68b73 805
1da177e4
LT
806/**
807 * container_of - cast a member of a structure out to the containing structure
1da177e4
LT
808 * @ptr: the pointer to the member.
809 * @type: the type of the container struct this is embedded in.
810 * @member: the name of the member within the struct.
811 *
812 */
813#define container_of(ptr, type, member) ({ \
78db2ad6
DW
814 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
815 (type *)( (char *)__mptr - offsetof(type,member) );})
1da177e4 816
b9d4f426
AL
817/* Trap pasters of __FUNCTION__ at compile-time */
818#define __FUNCTION__ (__func__)
819
b9d4f426
AL
820/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
821#ifdef CONFIG_FTRACE_MCOUNT_RECORD
822# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
823#endif
9d00f92f 824
1da177e4 825#endif
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