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
  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