include/linux/kernel.h

   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 extern void __attribute__((format(printf, 1, 2)))
 198         early_printk(const char *fmt, ...);
 199
 200 unsigned long int_sqrt(unsigned long);
 201
 202 extern int printk_ratelimit(void);
 203 extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
 204 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 205                                 unsigned int interval_msec);
 206
 207 static inline void console_silent(void)
 208 {
 209         console_loglevel = 0;
 210 }
 211
 212 static inline void console_verbose(void)
 213 {
 214         if (console_loglevel)
 215                 console_loglevel = 15;
 216 }
 217
 218 extern void bust_spinlocks(int yes);
 219 extern void wake_up_klogd(void);
 220 extern int oops_in_progress;            /* If set, an oops, panic(), BUG() or die() is in progress */
 221 extern int panic_timeout;
 222 extern int panic_on_oops;
 223 extern int panic_on_unrecovered_nmi;
 224 extern int tainted;
 225 extern const char *print_tainted(void);
 226 extern void add_taint(unsigned);
 227
 228 /* Values used for system_state */
 229 extern enum system_states {
 230         SYSTEM_BOOTING,
 231         SYSTEM_RUNNING,
 232         SYSTEM_HALT,
 233         SYSTEM_POWER_OFF,
 234         SYSTEM_RESTART,
 235         SYSTEM_SUSPEND_DISK,
 236 } system_state;
 237
 238 #define TAINT_PROPRIETARY_MODULE        (1<<0)
 239 #define TAINT_FORCED_MODULE             (1<<1)
 240 #define TAINT_UNSAFE_SMP                (1<<2)
 241 #define TAINT_FORCED_RMMOD              (1<<3)
 242 #define TAINT_MACHINE_CHECK             (1<<4)
 243 #define TAINT_BAD_PAGE                  (1<<5)
 244 #define TAINT_USER                      (1<<6)
 245 #define TAINT_DIE                       (1<<7)
 246
 247 extern void dump_stack(void) __cold;
 248
 249 enum {
 250         DUMP_PREFIX_NONE,
 251         DUMP_PREFIX_ADDRESS,
 252         DUMP_PREFIX_OFFSET
 253 };
 254 extern void hex_dump_to_buffer(const void *buf, size_t len,
 255                                 int rowsize, int groupsize,
 256                                 char *linebuf, size_t linebuflen, bool ascii);
 257 extern void print_hex_dump(const char *level, const char *prefix_str,
 258                                 int prefix_type, int rowsize, int groupsize,
 259                                 const void *buf, size_t len, bool ascii);
 260 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 261                         const void *buf, size_t len);
 262 #define hex_asc(x)      "0123456789abcdef"[x]
 263
 264 #define pr_emerg(fmt, arg...) \
 265         printk(KERN_EMERG fmt, ##arg)
 266 #define pr_alert(fmt, arg...) \
 267         printk(KERN_ALERT fmt, ##arg)
 268 #define pr_crit(fmt, arg...) \
 269         printk(KERN_CRIT fmt, ##arg)
 270 #define pr_err(fmt, arg...) \
 271         printk(KERN_ERR fmt, ##arg)
 272 #define pr_warning(fmt, arg...) \
 273         printk(KERN_WARNING fmt, ##arg)
 274 #define pr_notice(fmt, arg...) \
 275         printk(KERN_NOTICE fmt, ##arg)
 276 #define pr_info(fmt, arg...) \
 277         printk(KERN_INFO fmt, ##arg)
 278
 279 #ifdef DEBUG
 280 /* If you are writing a driver, please use dev_dbg instead */
 281 #define pr_debug(fmt, arg...) \
 282         printk(KERN_DEBUG fmt, ##arg)
 283 #else
 284 static inline int __attribute__ ((format (printf, 1, 2))) pr_debug(const char * fmt, ...)
 285 {
 286         return 0;
 287 }
 288 #endif
 289
 290 /*
 291  *      Display an IP address in readable format.
 292  */
 293
 294 #define NIPQUAD(addr) \
 295         ((unsigned char *)&addr)[0], \
 296         ((unsigned char *)&addr)[1], \
 297         ((unsigned char *)&addr)[2], \
 298         ((unsigned char *)&addr)[3]
 299 #define NIPQUAD_FMT "%u.%u.%u.%u"
 300
 301 #define NIP6(addr) \
 302         ntohs((addr).s6_addr16[0]), \
 303         ntohs((addr).s6_addr16[1]), \
 304         ntohs((addr).s6_addr16[2]), \
 305         ntohs((addr).s6_addr16[3]), \
 306         ntohs((addr).s6_addr16[4]), \
 307         ntohs((addr).s6_addr16[5]), \
 308         ntohs((addr).s6_addr16[6]), \
 309         ntohs((addr).s6_addr16[7])
 310 #define NIP6_FMT "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
 311 #define NIP6_SEQFMT "%04x%04x%04x%04x%04x%04x%04x%04x"
 312
 313 #if defined(__LITTLE_ENDIAN)
 314 #define HIPQUAD(addr) \
 315         ((unsigned char *)&addr)[3], \
 316         ((unsigned char *)&addr)[2], \
 317         ((unsigned char *)&addr)[1], \
 318         ((unsigned char *)&addr)[0]
 319 #elif defined(__BIG_ENDIAN)
 320 #define HIPQUAD NIPQUAD
 321 #else
 322 #error "Please fix asm/byteorder.h"
 323 #endif /* __LITTLE_ENDIAN */
 324
 325 /*
 326  * min()/max() macros that also do
 327  * strict type-checking.. See the
 328  * "unnecessary" pointer comparison.
 329  */
 330 #define min(x,y) ({ \
 331         typeof(x) _x = (x);     \
 332         typeof(y) _y = (y);     \
 333         (void) (&_x == &_y);            \
 334         _x < _y ? _x : _y; })
 335
 336 #define max(x,y) ({ \
 337         typeof(x) _x = (x);     \
 338         typeof(y) _y = (y);     \
 339         (void) (&_x == &_y);            \
 340         _x > _y ? _x : _y; })
 341
 342 /*
 343  * ..and if you can't take the strict
 344  * types, you can specify one yourself.
 345  *
 346  * Or not use min/max at all, of course.
 347  */
 348 #define min_t(type,x,y) \
 349         ({ type __x = (x); type __y = (y); __x < __y ? __x: __y; })
 350 #define max_t(type,x,y) \
 351         ({ type __x = (x); type __y = (y); __x > __y ? __x: __y; })
 352
 353
 354 /**
 355  * container_of - cast a member of a structure out to the containing structure
 356  * @ptr:        the pointer to the member.
 357  * @type:       the type of the container struct this is embedded in.
 358  * @member:     the name of the member within the struct.
 359  *
 360  */
 361 #define container_of(ptr, type, member) ({                      \
 362         const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
 363         (type *)( (char *)__mptr - offsetof(type,member) );})
 364
 365 /*
 366  * Check at compile time that something is of a particular type.
 367  * Always evaluates to 1 so you may use it easily in comparisons.
 368  */
 369 #define typecheck(type,x) \
 370 ({      type __dummy; \
 371         typeof(x) __dummy2; \
 372         (void)(&__dummy == &__dummy2); \
 373         1; \
 374 })
 375
 376 /*
 377  * Check at compile time that 'function' is a certain type, or is a pointer
 378  * to that type (needs to use typedef for the function type.)
 379  */
 380 #define typecheck_fn(type,function) \
 381 ({      typeof(type) __tmp = function; \
 382         (void)__tmp; \
 383 })
 384
 385 struct sysinfo;
 386 extern int do_sysinfo(struct sysinfo *info);
 387
 388 #endif /* __KERNEL__ */
 389
 390 #define SI_LOAD_SHIFT   16
 391 struct sysinfo {
 392         long uptime;                    /* Seconds since boot */
 393         unsigned long loads[3];         /* 1, 5, and 15 minute load averages */
 394         unsigned long totalram;         /* Total usable main memory size */
 395         unsigned long freeram;          /* Available memory size */
 396         unsigned long sharedram;        /* Amount of shared memory */
 397         unsigned long bufferram;        /* Memory used by buffers */
 398         unsigned long totalswap;        /* Total swap space size */
 399         unsigned long freeswap;         /* swap space still available */
 400         unsigned short procs;           /* Number of current processes */
 401         unsigned short pad;             /* explicit padding for m68k */
 402         unsigned long totalhigh;        /* Total high memory size */
 403         unsigned long freehigh;         /* Available high memory size */
 404         unsigned int mem_unit;          /* Memory unit size in bytes */
 405         char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
 406 };
 407
 408 /* Force a compilation error if condition is true */
 409 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
 410
 411 /* Force a compilation error if condition is true, but also produce a
 412    result (of value 0 and type size_t), so the expression can be used
 413    e.g. in a structure initializer (or where-ever else comma expressions
 414    aren't permitted). */
 415 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
 416
 417 /* Trap pasters of __FUNCTION__ at compile-time */
 418 #define __FUNCTION__ (__func__)
 419
 420 /* This helps us to avoid #ifdef CONFIG_NUMA */
 421 #ifdef CONFIG_NUMA
 422 #define NUMA_BUILD 1
 423 #else
 424 #define NUMA_BUILD 0
 425 #endif
 426
 427 #endif