xref: /linux-6.15/include/linux/kernel.h (revision 40efcb05)
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 #define PTR_ALIGN(p, a)		((typeof(p))ALIGN((unsigned long)(p), (a)))
38 #define IS_ALIGNED(x,a)		(((x) % ((typeof(x))(a))) == 0)
39 
40 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
41 
42 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
43 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
44 #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
45 
46 #ifdef CONFIG_LBD
47 # include <asm/div64.h>
48 # define sector_div(a, b) do_div(a, b)
49 #else
50 # define sector_div(n, b)( \
51 { \
52 	int _res; \
53 	_res = (n) % (b); \
54 	(n) /= (b); \
55 	_res; \
56 } \
57 )
58 #endif
59 
60 /**
61  * upper_32_bits - return bits 32-63 of a number
62  * @n: the number we're accessing
63  *
64  * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
65  * the "right shift count >= width of type" warning when that quantity is
66  * 32-bits.
67  */
68 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
69 
70 #define	KERN_EMERG	"<0>"	/* system is unusable			*/
71 #define	KERN_ALERT	"<1>"	/* action must be taken immediately	*/
72 #define	KERN_CRIT	"<2>"	/* critical conditions			*/
73 #define	KERN_ERR	"<3>"	/* error conditions			*/
74 #define	KERN_WARNING	"<4>"	/* warning conditions			*/
75 #define	KERN_NOTICE	"<5>"	/* normal but significant condition	*/
76 #define	KERN_INFO	"<6>"	/* informational			*/
77 #define	KERN_DEBUG	"<7>"	/* debug-level messages			*/
78 
79 /*
80  * Annotation for a "continued" line of log printout (only done after a
81  * line that had no enclosing \n). Only to be used by core/arch code
82  * during early bootup (a continued line is not SMP-safe otherwise).
83  */
84 #define	KERN_CONT	""
85 
86 extern int console_printk[];
87 
88 #define console_loglevel (console_printk[0])
89 #define default_message_loglevel (console_printk[1])
90 #define minimum_console_loglevel (console_printk[2])
91 #define default_console_loglevel (console_printk[3])
92 
93 struct completion;
94 struct pt_regs;
95 struct user;
96 
97 /**
98  * might_sleep - annotation for functions that can sleep
99  *
100  * this macro will print a stack trace if it is executed in an atomic
101  * context (spinlock, irq-handler, ...).
102  *
103  * This is a useful debugging help to be able to catch problems early and not
104  * be bitten later when the calling function happens to sleep when it is not
105  * supposed to.
106  */
107 #ifdef CONFIG_PREEMPT_VOLUNTARY
108 extern int cond_resched(void);
109 # define might_resched() cond_resched()
110 #else
111 # define might_resched() do { } while (0)
112 #endif
113 
114 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
115   void __might_sleep(char *file, int line);
116 # define might_sleep() \
117 	do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
118 #else
119 # define might_sleep() do { might_resched(); } while (0)
120 #endif
121 
122 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
123 
124 #define abs(x) ({				\
125 		int __x = (x);			\
126 		(__x < 0) ? -__x : __x;		\
127 	})
128 
129 extern struct atomic_notifier_head panic_notifier_list;
130 extern long (*panic_blink)(long time);
131 NORET_TYPE void panic(const char * fmt, ...)
132 	__attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
133 extern void oops_enter(void);
134 extern void oops_exit(void);
135 extern int oops_may_print(void);
136 fastcall NORET_TYPE void do_exit(long error_code)
137 	ATTRIB_NORET;
138 NORET_TYPE void complete_and_exit(struct completion *, long)
139 	ATTRIB_NORET;
140 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
141 extern long simple_strtol(const char *,char **,unsigned int);
142 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
143 extern long long simple_strtoll(const char *,char **,unsigned int);
144 extern int sprintf(char * buf, const char * fmt, ...)
145 	__attribute__ ((format (printf, 2, 3)));
146 extern int vsprintf(char *buf, const char *, va_list)
147 	__attribute__ ((format (printf, 2, 0)));
148 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
149 	__attribute__ ((format (printf, 3, 4)));
150 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
151 	__attribute__ ((format (printf, 3, 0)));
152 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
153 	__attribute__ ((format (printf, 3, 4)));
154 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
155 	__attribute__ ((format (printf, 3, 0)));
156 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
157 	__attribute__ ((format (printf, 2, 3)));
158 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
159 
160 extern int sscanf(const char *, const char *, ...)
161 	__attribute__ ((format (scanf, 2, 3)));
162 extern int vsscanf(const char *, const char *, va_list)
163 	__attribute__ ((format (scanf, 2, 0)));
164 
165 extern int get_option(char **str, int *pint);
166 extern char *get_options(const char *str, int nints, int *ints);
167 extern unsigned long long memparse(char *ptr, char **retptr);
168 
169 extern int core_kernel_text(unsigned long addr);
170 extern int __kernel_text_address(unsigned long addr);
171 extern int kernel_text_address(unsigned long addr);
172 struct pid;
173 extern struct pid *session_of_pgrp(struct pid *pgrp);
174 
175 extern void dump_thread(struct pt_regs *regs, struct user *dump);
176 
177 #ifdef CONFIG_PRINTK
178 asmlinkage int vprintk(const char *fmt, va_list args)
179 	__attribute__ ((format (printf, 1, 0)));
180 asmlinkage int printk(const char * fmt, ...)
181 	__attribute__ ((format (printf, 1, 2))) __cold;
182 extern int log_buf_get_len(void);
183 extern int log_buf_read(int idx);
184 extern int log_buf_copy(char *dest, int idx, int len);
185 #else
186 static inline int vprintk(const char *s, va_list args)
187 	__attribute__ ((format (printf, 1, 0)));
188 static inline int vprintk(const char *s, va_list args) { return 0; }
189 static inline int printk(const char *s, ...)
190 	__attribute__ ((format (printf, 1, 2)));
191 static inline int __cold printk(const char *s, ...) { return 0; }
192 static inline int log_buf_get_len(void) { return 0; }
193 static inline int log_buf_read(int idx) { return 0; }
194 static inline int log_buf_copy(char *dest, int idx, int len) { return 0; }
195 #endif
196 
197 unsigned long int_sqrt(unsigned long);
198 
199 extern int printk_ratelimit(void);
200 extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
201 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
202 				unsigned int interval_msec);
203 
204 static inline void console_silent(void)
205 {
206 	console_loglevel = 0;
207 }
208 
209 static inline void console_verbose(void)
210 {
211 	if (console_loglevel)
212 		console_loglevel = 15;
213 }
214 
215 extern void bust_spinlocks(int yes);
216 extern void wake_up_klogd(void);
217 extern int oops_in_progress;		/* If set, an oops, panic(), BUG() or die() is in progress */
218 extern int panic_timeout;
219 extern int panic_on_oops;
220 extern int panic_on_unrecovered_nmi;
221 extern int tainted;
222 extern const char *print_tainted(void);
223 extern void add_taint(unsigned);
224 
225 /* Values used for system_state */
226 extern enum system_states {
227 	SYSTEM_BOOTING,
228 	SYSTEM_RUNNING,
229 	SYSTEM_HALT,
230 	SYSTEM_POWER_OFF,
231 	SYSTEM_RESTART,
232 	SYSTEM_SUSPEND_DISK,
233 } system_state;
234 
235 #define TAINT_PROPRIETARY_MODULE	(1<<0)
236 #define TAINT_FORCED_MODULE		(1<<1)
237 #define TAINT_UNSAFE_SMP		(1<<2)
238 #define TAINT_FORCED_RMMOD		(1<<3)
239 #define TAINT_MACHINE_CHECK		(1<<4)
240 #define TAINT_BAD_PAGE			(1<<5)
241 #define TAINT_USER			(1<<6)
242 #define TAINT_DIE			(1<<7)
243 
244 extern void dump_stack(void) __cold;
245 
246 enum {
247 	DUMP_PREFIX_NONE,
248 	DUMP_PREFIX_ADDRESS,
249 	DUMP_PREFIX_OFFSET
250 };
251 extern void hex_dump_to_buffer(const void *buf, size_t len,
252 				int rowsize, int groupsize,
253 				char *linebuf, size_t linebuflen, bool ascii);
254 extern void print_hex_dump(const char *level, const char *prefix_str,
255 				int prefix_type, int rowsize, int groupsize,
256 				const void *buf, size_t len, bool ascii);
257 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
258 			const void *buf, size_t len);
259 #define hex_asc(x)	"0123456789abcdef"[x]
260 
261 #define pr_emerg(fmt, arg...) \
262 	printk(KERN_EMERG fmt, ##arg)
263 #define pr_alert(fmt, arg...) \
264 	printk(KERN_ALERT fmt, ##arg)
265 #define pr_crit(fmt, arg...) \
266 	printk(KERN_CRIT fmt, ##arg)
267 #define pr_err(fmt, arg...) \
268 	printk(KERN_ERR fmt, ##arg)
269 #define pr_warning(fmt, arg...) \
270 	printk(KERN_WARNING fmt, ##arg)
271 #define pr_notice(fmt, arg...) \
272 	printk(KERN_NOTICE fmt, ##arg)
273 #define pr_info(fmt, arg...) \
274 	printk(KERN_INFO fmt, ##arg)
275 
276 #ifdef DEBUG
277 /* If you are writing a driver, please use dev_dbg instead */
278 #define pr_debug(fmt, arg...) \
279 	printk(KERN_DEBUG fmt, ##arg)
280 #else
281 static inline int __attribute__ ((format (printf, 1, 2))) pr_debug(const char * fmt, ...)
282 {
283 	return 0;
284 }
285 #endif
286 
287 /*
288  *      Display an IP address in readable format.
289  */
290 
291 #define NIPQUAD(addr) \
292 	((unsigned char *)&addr)[0], \
293 	((unsigned char *)&addr)[1], \
294 	((unsigned char *)&addr)[2], \
295 	((unsigned char *)&addr)[3]
296 #define NIPQUAD_FMT "%u.%u.%u.%u"
297 
298 #define NIP6(addr) \
299 	ntohs((addr).s6_addr16[0]), \
300 	ntohs((addr).s6_addr16[1]), \
301 	ntohs((addr).s6_addr16[2]), \
302 	ntohs((addr).s6_addr16[3]), \
303 	ntohs((addr).s6_addr16[4]), \
304 	ntohs((addr).s6_addr16[5]), \
305 	ntohs((addr).s6_addr16[6]), \
306 	ntohs((addr).s6_addr16[7])
307 #define NIP6_FMT "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
308 #define NIP6_SEQFMT "%04x%04x%04x%04x%04x%04x%04x%04x"
309 
310 #if defined(__LITTLE_ENDIAN)
311 #define HIPQUAD(addr) \
312 	((unsigned char *)&addr)[3], \
313 	((unsigned char *)&addr)[2], \
314 	((unsigned char *)&addr)[1], \
315 	((unsigned char *)&addr)[0]
316 #elif defined(__BIG_ENDIAN)
317 #define HIPQUAD	NIPQUAD
318 #else
319 #error "Please fix asm/byteorder.h"
320 #endif /* __LITTLE_ENDIAN */
321 
322 /*
323  * min()/max() macros that also do
324  * strict type-checking.. See the
325  * "unnecessary" pointer comparison.
326  */
327 #define min(x,y) ({ \
328 	typeof(x) _x = (x);	\
329 	typeof(y) _y = (y);	\
330 	(void) (&_x == &_y);		\
331 	_x < _y ? _x : _y; })
332 
333 #define max(x,y) ({ \
334 	typeof(x) _x = (x);	\
335 	typeof(y) _y = (y);	\
336 	(void) (&_x == &_y);		\
337 	_x > _y ? _x : _y; })
338 
339 /*
340  * ..and if you can't take the strict
341  * types, you can specify one yourself.
342  *
343  * Or not use min/max at all, of course.
344  */
345 #define min_t(type,x,y) \
346 	({ type __x = (x); type __y = (y); __x < __y ? __x: __y; })
347 #define max_t(type,x,y) \
348 	({ type __x = (x); type __y = (y); __x > __y ? __x: __y; })
349 
350 
351 /**
352  * container_of - cast a member of a structure out to the containing structure
353  * @ptr:	the pointer to the member.
354  * @type:	the type of the container struct this is embedded in.
355  * @member:	the name of the member within the struct.
356  *
357  */
358 #define container_of(ptr, type, member) ({			\
359 	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
360 	(type *)( (char *)__mptr - offsetof(type,member) );})
361 
362 /*
363  * Check at compile time that something is of a particular type.
364  * Always evaluates to 1 so you may use it easily in comparisons.
365  */
366 #define typecheck(type,x) \
367 ({	type __dummy; \
368 	typeof(x) __dummy2; \
369 	(void)(&__dummy == &__dummy2); \
370 	1; \
371 })
372 
373 /*
374  * Check at compile time that 'function' is a certain type, or is a pointer
375  * to that type (needs to use typedef for the function type.)
376  */
377 #define typecheck_fn(type,function) \
378 ({	typeof(type) __tmp = function; \
379 	(void)__tmp; \
380 })
381 
382 struct sysinfo;
383 extern int do_sysinfo(struct sysinfo *info);
384 
385 #endif /* __KERNEL__ */
386 
387 #define SI_LOAD_SHIFT	16
388 struct sysinfo {
389 	long uptime;			/* Seconds since boot */
390 	unsigned long loads[3];		/* 1, 5, and 15 minute load averages */
391 	unsigned long totalram;		/* Total usable main memory size */
392 	unsigned long freeram;		/* Available memory size */
393 	unsigned long sharedram;	/* Amount of shared memory */
394 	unsigned long bufferram;	/* Memory used by buffers */
395 	unsigned long totalswap;	/* Total swap space size */
396 	unsigned long freeswap;		/* swap space still available */
397 	unsigned short procs;		/* Number of current processes */
398 	unsigned short pad;		/* explicit padding for m68k */
399 	unsigned long totalhigh;	/* Total high memory size */
400 	unsigned long freehigh;		/* Available high memory size */
401 	unsigned int mem_unit;		/* Memory unit size in bytes */
402 	char _f[20-2*sizeof(long)-sizeof(int)];	/* Padding: libc5 uses this.. */
403 };
404 
405 /* Force a compilation error if condition is true */
406 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
407 
408 /* Force a compilation error if condition is true, but also produce a
409    result (of value 0 and type size_t), so the expression can be used
410    e.g. in a structure initializer (or where-ever else comma expressions
411    aren't permitted). */
412 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
413 
414 /* Trap pasters of __FUNCTION__ at compile-time */
415 #define __FUNCTION__ (__func__)
416 
417 /* This helps us to avoid #ifdef CONFIG_NUMA */
418 #ifdef CONFIG_NUMA
419 #define NUMA_BUILD 1
420 #else
421 #define NUMA_BUILD 0
422 #endif
423 
424 #endif
425