xref: /linux-6.15/include/linux/kernel.h (revision b454cc66)
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 #define labs(x) ({				\
96 		long __x = (x);			\
97 		(__x < 0) ? -__x : __x;		\
98 	})
99 
100 extern struct atomic_notifier_head panic_notifier_list;
101 extern long (*panic_blink)(long time);
102 NORET_TYPE void panic(const char * fmt, ...)
103 	__attribute__ ((NORET_AND format (printf, 1, 2)));
104 extern void oops_enter(void);
105 extern void oops_exit(void);
106 extern int oops_may_print(void);
107 fastcall NORET_TYPE void do_exit(long error_code)
108 	ATTRIB_NORET;
109 NORET_TYPE void complete_and_exit(struct completion *, long)
110 	ATTRIB_NORET;
111 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
112 extern long simple_strtol(const char *,char **,unsigned int);
113 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
114 extern long long simple_strtoll(const char *,char **,unsigned int);
115 extern int sprintf(char * buf, const char * fmt, ...)
116 	__attribute__ ((format (printf, 2, 3)));
117 extern int vsprintf(char *buf, const char *, va_list)
118 	__attribute__ ((format (printf, 2, 0)));
119 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
120 	__attribute__ ((format (printf, 3, 4)));
121 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
122 	__attribute__ ((format (printf, 3, 0)));
123 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
124 	__attribute__ ((format (printf, 3, 4)));
125 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
126 	__attribute__ ((format (printf, 3, 0)));
127 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
128 	__attribute__ ((format (printf, 2, 3)));
129 
130 extern int sscanf(const char *, const char *, ...)
131 	__attribute__ ((format (scanf, 2, 3)));
132 extern int vsscanf(const char *, const char *, va_list)
133 	__attribute__ ((format (scanf, 2, 0)));
134 
135 extern int get_option(char **str, int *pint);
136 extern char *get_options(const char *str, int nints, int *ints);
137 extern unsigned long long memparse(char *ptr, char **retptr);
138 
139 extern int core_kernel_text(unsigned long addr);
140 extern int __kernel_text_address(unsigned long addr);
141 extern int kernel_text_address(unsigned long addr);
142 extern int session_of_pgrp(int pgrp);
143 
144 extern void dump_thread(struct pt_regs *regs, struct user *dump);
145 
146 #ifdef CONFIG_PRINTK
147 asmlinkage int vprintk(const char *fmt, va_list args)
148 	__attribute__ ((format (printf, 1, 0)));
149 asmlinkage int printk(const char * fmt, ...)
150 	__attribute__ ((format (printf, 1, 2)));
151 #else
152 static inline int vprintk(const char *s, va_list args)
153 	__attribute__ ((format (printf, 1, 0)));
154 static inline int vprintk(const char *s, va_list args) { return 0; }
155 static inline int printk(const char *s, ...)
156 	__attribute__ ((format (printf, 1, 2)));
157 static inline int printk(const char *s, ...) { return 0; }
158 #endif
159 
160 unsigned long int_sqrt(unsigned long);
161 
162 extern int printk_ratelimit(void);
163 extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
164 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
165 				unsigned int interval_msec);
166 
167 static inline void console_silent(void)
168 {
169 	console_loglevel = 0;
170 }
171 
172 static inline void console_verbose(void)
173 {
174 	if (console_loglevel)
175 		console_loglevel = 15;
176 }
177 
178 extern void bust_spinlocks(int yes);
179 extern int oops_in_progress;		/* If set, an oops, panic(), BUG() or die() is in progress */
180 extern int panic_timeout;
181 extern int panic_on_oops;
182 extern int panic_on_unrecovered_nmi;
183 extern int tainted;
184 extern const char *print_tainted(void);
185 extern void add_taint(unsigned);
186 
187 /* Values used for system_state */
188 extern enum system_states {
189 	SYSTEM_BOOTING,
190 	SYSTEM_RUNNING,
191 	SYSTEM_HALT,
192 	SYSTEM_POWER_OFF,
193 	SYSTEM_RESTART,
194 	SYSTEM_SUSPEND_DISK,
195 } system_state;
196 
197 #define TAINT_PROPRIETARY_MODULE	(1<<0)
198 #define TAINT_FORCED_MODULE		(1<<1)
199 #define TAINT_UNSAFE_SMP		(1<<2)
200 #define TAINT_FORCED_RMMOD		(1<<3)
201 #define TAINT_MACHINE_CHECK		(1<<4)
202 #define TAINT_BAD_PAGE			(1<<5)
203 
204 extern void dump_stack(void);
205 
206 #ifdef DEBUG
207 /* If you are writing a driver, please use dev_dbg instead */
208 #define pr_debug(fmt,arg...) \
209 	printk(KERN_DEBUG fmt,##arg)
210 #else
211 static inline int __attribute__ ((format (printf, 1, 2))) pr_debug(const char * fmt, ...)
212 {
213 	return 0;
214 }
215 #endif
216 
217 #define pr_info(fmt,arg...) \
218 	printk(KERN_INFO fmt,##arg)
219 
220 /*
221  *      Display an IP address in readable format.
222  */
223 
224 #define NIPQUAD(addr) \
225 	((unsigned char *)&addr)[0], \
226 	((unsigned char *)&addr)[1], \
227 	((unsigned char *)&addr)[2], \
228 	((unsigned char *)&addr)[3]
229 #define NIPQUAD_FMT "%u.%u.%u.%u"
230 
231 #define NIP6(addr) \
232 	ntohs((addr).s6_addr16[0]), \
233 	ntohs((addr).s6_addr16[1]), \
234 	ntohs((addr).s6_addr16[2]), \
235 	ntohs((addr).s6_addr16[3]), \
236 	ntohs((addr).s6_addr16[4]), \
237 	ntohs((addr).s6_addr16[5]), \
238 	ntohs((addr).s6_addr16[6]), \
239 	ntohs((addr).s6_addr16[7])
240 #define NIP6_FMT "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
241 #define NIP6_SEQFMT "%04x%04x%04x%04x%04x%04x%04x%04x"
242 
243 #if defined(__LITTLE_ENDIAN)
244 #define HIPQUAD(addr) \
245 	((unsigned char *)&addr)[3], \
246 	((unsigned char *)&addr)[2], \
247 	((unsigned char *)&addr)[1], \
248 	((unsigned char *)&addr)[0]
249 #elif defined(__BIG_ENDIAN)
250 #define HIPQUAD	NIPQUAD
251 #else
252 #error "Please fix asm/byteorder.h"
253 #endif /* __LITTLE_ENDIAN */
254 
255 /*
256  * min()/max() macros that also do
257  * strict type-checking.. See the
258  * "unnecessary" pointer comparison.
259  */
260 #define min(x,y) ({ \
261 	typeof(x) _x = (x);	\
262 	typeof(y) _y = (y);	\
263 	(void) (&_x == &_y);		\
264 	_x < _y ? _x : _y; })
265 
266 #define max(x,y) ({ \
267 	typeof(x) _x = (x);	\
268 	typeof(y) _y = (y);	\
269 	(void) (&_x == &_y);		\
270 	_x > _y ? _x : _y; })
271 
272 /*
273  * ..and if you can't take the strict
274  * types, you can specify one yourself.
275  *
276  * Or not use min/max at all, of course.
277  */
278 #define min_t(type,x,y) \
279 	({ type __x = (x); type __y = (y); __x < __y ? __x: __y; })
280 #define max_t(type,x,y) \
281 	({ type __x = (x); type __y = (y); __x > __y ? __x: __y; })
282 
283 
284 /**
285  * container_of - cast a member of a structure out to the containing structure
286  * @ptr:	the pointer to the member.
287  * @type:	the type of the container struct this is embedded in.
288  * @member:	the name of the member within the struct.
289  *
290  */
291 #define container_of(ptr, type, member) ({			\
292         const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
293         (type *)( (char *)__mptr - offsetof(type,member) );})
294 
295 /*
296  * Check at compile time that something is of a particular type.
297  * Always evaluates to 1 so you may use it easily in comparisons.
298  */
299 #define typecheck(type,x) \
300 ({	type __dummy; \
301 	typeof(x) __dummy2; \
302 	(void)(&__dummy == &__dummy2); \
303 	1; \
304 })
305 
306 /*
307  * Check at compile time that 'function' is a certain type, or is a pointer
308  * to that type (needs to use typedef for the function type.)
309  */
310 #define typecheck_fn(type,function) \
311 ({	typeof(type) __tmp = function; \
312 	(void)__tmp; \
313 })
314 
315 #endif /* __KERNEL__ */
316 
317 #define SI_LOAD_SHIFT	16
318 struct sysinfo {
319 	long uptime;			/* Seconds since boot */
320 	unsigned long loads[3];		/* 1, 5, and 15 minute load averages */
321 	unsigned long totalram;		/* Total usable main memory size */
322 	unsigned long freeram;		/* Available memory size */
323 	unsigned long sharedram;	/* Amount of shared memory */
324 	unsigned long bufferram;	/* Memory used by buffers */
325 	unsigned long totalswap;	/* Total swap space size */
326 	unsigned long freeswap;		/* swap space still available */
327 	unsigned short procs;		/* Number of current processes */
328 	unsigned short pad;		/* explicit padding for m68k */
329 	unsigned long totalhigh;	/* Total high memory size */
330 	unsigned long freehigh;		/* Available high memory size */
331 	unsigned int mem_unit;		/* Memory unit size in bytes */
332 	char _f[20-2*sizeof(long)-sizeof(int)];	/* Padding: libc5 uses this.. */
333 };
334 
335 /* Force a compilation error if condition is true */
336 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
337 
338 /* Force a compilation error if condition is true, but also produce a
339    result (of value 0 and type size_t), so the expression can be used
340    e.g. in a structure initializer (or where-ever else comma expressions
341    aren't permitted). */
342 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
343 
344 /* Trap pasters of __FUNCTION__ at compile-time */
345 #define __FUNCTION__ (__func__)
346 
347 /* This helps us to avoid #ifdef CONFIG_NUMA */
348 #ifdef CONFIG_NUMA
349 #define NUMA_BUILD 1
350 #else
351 #define NUMA_BUILD 0
352 #endif
353 
354 #endif
355