xref: /linux-6.15/include/linux/kernel.h (revision eb2bce7f)
1 #ifndef _LINUX_KERNEL_H
2 #define _LINUX_KERNEL_H
3 
4 /*
5  * 'kernel.h' contains some often-used function prototypes etc
6  */
7 
8 #ifdef __KERNEL__
9 
10 #include <stdarg.h>
11 #include <linux/linkage.h>
12 #include <linux/stddef.h>
13 #include <linux/types.h>
14 #include <linux/compiler.h>
15 #include <linux/bitops.h>
16 #include <linux/log2.h>
17 #include <asm/byteorder.h>
18 #include <asm/bug.h>
19 
20 extern const char linux_banner[];
21 extern const char linux_proc_banner[];
22 
23 #define INT_MAX		((int)(~0U>>1))
24 #define INT_MIN		(-INT_MAX - 1)
25 #define UINT_MAX	(~0U)
26 #define LONG_MAX	((long)(~0UL>>1))
27 #define LONG_MIN	(-LONG_MAX - 1)
28 #define ULONG_MAX	(~0UL)
29 #define LLONG_MAX	((long long)(~0ULL>>1))
30 #define LLONG_MIN	(-LLONG_MAX - 1)
31 #define ULLONG_MAX	(~0ULL)
32 
33 #define STACK_MAGIC	0xdeadbeef
34 
35 #define ALIGN(x,a)		__ALIGN_MASK(x,(typeof(x))(a)-1)
36 #define __ALIGN_MASK(x,mask)	(((x)+(mask))&~(mask))
37 
38 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
39 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
40 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
41 #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
42 
43 #define	KERN_EMERG	"<0>"	/* system is unusable			*/
44 #define	KERN_ALERT	"<1>"	/* action must be taken immediately	*/
45 #define	KERN_CRIT	"<2>"	/* critical conditions			*/
46 #define	KERN_ERR	"<3>"	/* error conditions			*/
47 #define	KERN_WARNING	"<4>"	/* warning conditions			*/
48 #define	KERN_NOTICE	"<5>"	/* normal but significant condition	*/
49 #define	KERN_INFO	"<6>"	/* informational			*/
50 #define	KERN_DEBUG	"<7>"	/* debug-level messages			*/
51 
52 extern int console_printk[];
53 
54 #define console_loglevel (console_printk[0])
55 #define default_message_loglevel (console_printk[1])
56 #define minimum_console_loglevel (console_printk[2])
57 #define default_console_loglevel (console_printk[3])
58 
59 struct completion;
60 struct pt_regs;
61 struct user;
62 
63 /**
64  * might_sleep - annotation for functions that can sleep
65  *
66  * this macro will print a stack trace if it is executed in an atomic
67  * context (spinlock, irq-handler, ...).
68  *
69  * This is a useful debugging help to be able to catch problems early and not
70  * be bitten later when the calling function happens to sleep when it is not
71  * supposed to.
72  */
73 #ifdef CONFIG_PREEMPT_VOLUNTARY
74 extern int cond_resched(void);
75 # define might_resched() cond_resched()
76 #else
77 # define might_resched() do { } while (0)
78 #endif
79 
80 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
81   void __might_sleep(char *file, int line);
82 # define might_sleep() \
83 	do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
84 #else
85 # define might_sleep() do { might_resched(); } while (0)
86 #endif
87 
88 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
89 
90 #define abs(x) ({				\
91 		int __x = (x);			\
92 		(__x < 0) ? -__x : __x;		\
93 	})
94 
95 extern struct atomic_notifier_head panic_notifier_list;
96 extern long (*panic_blink)(long time);
97 NORET_TYPE void panic(const char * fmt, ...)
98 	__attribute__ ((NORET_AND format (printf, 1, 2)));
99 extern void oops_enter(void);
100 extern void oops_exit(void);
101 extern int oops_may_print(void);
102 fastcall NORET_TYPE void do_exit(long error_code)
103 	ATTRIB_NORET;
104 NORET_TYPE void complete_and_exit(struct completion *, long)
105 	ATTRIB_NORET;
106 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
107 extern long simple_strtol(const char *,char **,unsigned int);
108 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
109 extern long long simple_strtoll(const char *,char **,unsigned int);
110 extern int sprintf(char * buf, const char * fmt, ...)
111 	__attribute__ ((format (printf, 2, 3)));
112 extern int vsprintf(char *buf, const char *, va_list)
113 	__attribute__ ((format (printf, 2, 0)));
114 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
115 	__attribute__ ((format (printf, 3, 4)));
116 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
117 	__attribute__ ((format (printf, 3, 0)));
118 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
119 	__attribute__ ((format (printf, 3, 4)));
120 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
121 	__attribute__ ((format (printf, 3, 0)));
122 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
123 	__attribute__ ((format (printf, 2, 3)));
124 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
125 
126 extern int sscanf(const char *, const char *, ...)
127 	__attribute__ ((format (scanf, 2, 3)));
128 extern int vsscanf(const char *, const char *, va_list)
129 	__attribute__ ((format (scanf, 2, 0)));
130 
131 extern int get_option(char **str, int *pint);
132 extern char *get_options(const char *str, int nints, int *ints);
133 extern unsigned long long memparse(char *ptr, char **retptr);
134 
135 extern int core_kernel_text(unsigned long addr);
136 extern int __kernel_text_address(unsigned long addr);
137 extern int kernel_text_address(unsigned long addr);
138 struct pid;
139 extern struct pid *session_of_pgrp(struct pid *pgrp);
140 
141 extern void dump_thread(struct pt_regs *regs, struct user *dump);
142 
143 #ifdef CONFIG_PRINTK
144 asmlinkage int vprintk(const char *fmt, va_list args)
145 	__attribute__ ((format (printf, 1, 0)));
146 asmlinkage int printk(const char * fmt, ...)
147 	__attribute__ ((format (printf, 1, 2)));
148 #else
149 static inline int vprintk(const char *s, va_list args)
150 	__attribute__ ((format (printf, 1, 0)));
151 static inline int vprintk(const char *s, va_list args) { return 0; }
152 static inline int printk(const char *s, ...)
153 	__attribute__ ((format (printf, 1, 2)));
154 static inline int printk(const char *s, ...) { return 0; }
155 #endif
156 
157 unsigned long int_sqrt(unsigned long);
158 
159 extern int printk_ratelimit(void);
160 extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
161 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
162 				unsigned int interval_msec);
163 
164 static inline void console_silent(void)
165 {
166 	console_loglevel = 0;
167 }
168 
169 static inline void console_verbose(void)
170 {
171 	if (console_loglevel)
172 		console_loglevel = 15;
173 }
174 
175 extern void bust_spinlocks(int yes);
176 extern void wake_up_klogd(void);
177 extern int oops_in_progress;		/* If set, an oops, panic(), BUG() or die() is in progress */
178 extern int panic_timeout;
179 extern int panic_on_oops;
180 extern int panic_on_unrecovered_nmi;
181 extern int tainted;
182 extern const char *print_tainted(void);
183 extern void add_taint(unsigned);
184 
185 /* Values used for system_state */
186 extern enum system_states {
187 	SYSTEM_BOOTING,
188 	SYSTEM_RUNNING,
189 	SYSTEM_HALT,
190 	SYSTEM_POWER_OFF,
191 	SYSTEM_RESTART,
192 	SYSTEM_SUSPEND_DISK,
193 } system_state;
194 
195 #define TAINT_PROPRIETARY_MODULE	(1<<0)
196 #define TAINT_FORCED_MODULE		(1<<1)
197 #define TAINT_UNSAFE_SMP		(1<<2)
198 #define TAINT_FORCED_RMMOD		(1<<3)
199 #define TAINT_MACHINE_CHECK		(1<<4)
200 #define TAINT_BAD_PAGE			(1<<5)
201 #define TAINT_USER			(1<<6)
202 
203 extern void dump_stack(void);
204 
205 #ifdef DEBUG
206 /* If you are writing a driver, please use dev_dbg instead */
207 #define pr_debug(fmt,arg...) \
208 	printk(KERN_DEBUG fmt,##arg)
209 #else
210 static inline int __attribute__ ((format (printf, 1, 2))) pr_debug(const char * fmt, ...)
211 {
212 	return 0;
213 }
214 #endif
215 
216 #define pr_info(fmt,arg...) \
217 	printk(KERN_INFO fmt,##arg)
218 
219 /*
220  *      Display an IP address in readable format.
221  */
222 
223 #define NIPQUAD(addr) \
224 	((unsigned char *)&addr)[0], \
225 	((unsigned char *)&addr)[1], \
226 	((unsigned char *)&addr)[2], \
227 	((unsigned char *)&addr)[3]
228 #define NIPQUAD_FMT "%u.%u.%u.%u"
229 
230 #define NIP6(addr) \
231 	ntohs((addr).s6_addr16[0]), \
232 	ntohs((addr).s6_addr16[1]), \
233 	ntohs((addr).s6_addr16[2]), \
234 	ntohs((addr).s6_addr16[3]), \
235 	ntohs((addr).s6_addr16[4]), \
236 	ntohs((addr).s6_addr16[5]), \
237 	ntohs((addr).s6_addr16[6]), \
238 	ntohs((addr).s6_addr16[7])
239 #define NIP6_FMT "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
240 #define NIP6_SEQFMT "%04x%04x%04x%04x%04x%04x%04x%04x"
241 
242 #if defined(__LITTLE_ENDIAN)
243 #define HIPQUAD(addr) \
244 	((unsigned char *)&addr)[3], \
245 	((unsigned char *)&addr)[2], \
246 	((unsigned char *)&addr)[1], \
247 	((unsigned char *)&addr)[0]
248 #elif defined(__BIG_ENDIAN)
249 #define HIPQUAD	NIPQUAD
250 #else
251 #error "Please fix asm/byteorder.h"
252 #endif /* __LITTLE_ENDIAN */
253 
254 /*
255  * min()/max() macros that also do
256  * strict type-checking.. See the
257  * "unnecessary" pointer comparison.
258  */
259 #define min(x,y) ({ \
260 	typeof(x) _x = (x);	\
261 	typeof(y) _y = (y);	\
262 	(void) (&_x == &_y);		\
263 	_x < _y ? _x : _y; })
264 
265 #define max(x,y) ({ \
266 	typeof(x) _x = (x);	\
267 	typeof(y) _y = (y);	\
268 	(void) (&_x == &_y);		\
269 	_x > _y ? _x : _y; })
270 
271 /*
272  * ..and if you can't take the strict
273  * types, you can specify one yourself.
274  *
275  * Or not use min/max at all, of course.
276  */
277 #define min_t(type,x,y) \
278 	({ type __x = (x); type __y = (y); __x < __y ? __x: __y; })
279 #define max_t(type,x,y) \
280 	({ type __x = (x); type __y = (y); __x > __y ? __x: __y; })
281 
282 
283 /**
284  * container_of - cast a member of a structure out to the containing structure
285  * @ptr:	the pointer to the member.
286  * @type:	the type of the container struct this is embedded in.
287  * @member:	the name of the member within the struct.
288  *
289  */
290 #define container_of(ptr, type, member) ({			\
291         const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
292         (type *)( (char *)__mptr - offsetof(type,member) );})
293 
294 /*
295  * Check at compile time that something is of a particular type.
296  * Always evaluates to 1 so you may use it easily in comparisons.
297  */
298 #define typecheck(type,x) \
299 ({	type __dummy; \
300 	typeof(x) __dummy2; \
301 	(void)(&__dummy == &__dummy2); \
302 	1; \
303 })
304 
305 /*
306  * Check at compile time that 'function' is a certain type, or is a pointer
307  * to that type (needs to use typedef for the function type.)
308  */
309 #define typecheck_fn(type,function) \
310 ({	typeof(type) __tmp = function; \
311 	(void)__tmp; \
312 })
313 
314 struct sysinfo;
315 extern int do_sysinfo(struct sysinfo *info);
316 
317 #endif /* __KERNEL__ */
318 
319 #define SI_LOAD_SHIFT	16
320 struct sysinfo {
321 	long uptime;			/* Seconds since boot */
322 	unsigned long loads[3];		/* 1, 5, and 15 minute load averages */
323 	unsigned long totalram;		/* Total usable main memory size */
324 	unsigned long freeram;		/* Available memory size */
325 	unsigned long sharedram;	/* Amount of shared memory */
326 	unsigned long bufferram;	/* Memory used by buffers */
327 	unsigned long totalswap;	/* Total swap space size */
328 	unsigned long freeswap;		/* swap space still available */
329 	unsigned short procs;		/* Number of current processes */
330 	unsigned short pad;		/* explicit padding for m68k */
331 	unsigned long totalhigh;	/* Total high memory size */
332 	unsigned long freehigh;		/* Available high memory size */
333 	unsigned int mem_unit;		/* Memory unit size in bytes */
334 	char _f[20-2*sizeof(long)-sizeof(int)];	/* Padding: libc5 uses this.. */
335 };
336 
337 /* Force a compilation error if condition is true */
338 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
339 
340 /* Force a compilation error if condition is true, but also produce a
341    result (of value 0 and type size_t), so the expression can be used
342    e.g. in a structure initializer (or where-ever else comma expressions
343    aren't permitted). */
344 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
345 
346 /* Trap pasters of __FUNCTION__ at compile-time */
347 #define __FUNCTION__ (__func__)
348 
349 /* This helps us to avoid #ifdef CONFIG_NUMA */
350 #ifdef CONFIG_NUMA
351 #define NUMA_BUILD 1
352 #else
353 #define NUMA_BUILD 0
354 #endif
355 
356 #endif
357