kernel-ark/include/linux/kernel.h
Andi Kleen a586df067a x86: Support __attribute__((__cold__)) in gcc 4.3
gcc 4.3 supports a new __attribute__((__cold__)) to mark functions cold. Any
path directly leading to a call of this function will be unlikely. And gcc
will try to generate smaller code for the function itself.

Please use with care. The code generation advantage isn't large and in most
cases it is not worth uglifying code with this.

This patch marks some common error functions like panic(), printk()
as cold.  This will longer term make many unlikely()s unnecessary, although
we can keep them for now for older compilers.

BUG is not marked cold because there is currently no way to tell
gcc to mark a inline function told.

Also all __init and __exit functions are marked cold. With a non -Os
build this will tell the compiler to generate slightly smaller code
for them. I think it currently only uses less alignments for labels,
but that might change in the future.

One disadvantage over *likely() is that they cannot be easily instrumented
to verify them.

Another drawback is that only the latest gcc 4.3 snapshots support this.
Unfortunately we cannot detect this using the preprocessor. This means older
snapshots will fail now. I don't think that's a problem because they are
unreleased compilers that nobody should be using.

gcc also has a __hot__ attribute, but I don't see any sense in using
this in the kernel right now. But someday I hope gcc will be able
to use more aggressive optimizing for hot functions even in -Os,
if that happens it should be added.

Includes compile fix from Thomas Gleixner.

Cc: Jan Hubicka <jh@suse.cz>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-21 18:37:08 -07:00

384 lines
12 KiB
C

#ifndef _LINUX_KERNEL_H
#define _LINUX_KERNEL_H
/*
* 'kernel.h' contains some often-used function prototypes etc
*/
#ifdef __KERNEL__
#include <stdarg.h>
#include <linux/linkage.h>
#include <linux/stddef.h>
#include <linux/types.h>
#include <linux/compiler.h>
#include <linux/bitops.h>
#include <linux/log2.h>
#include <asm/byteorder.h>
#include <asm/bug.h>
extern const char linux_banner[];
extern const char linux_proc_banner[];
#define INT_MAX ((int)(~0U>>1))
#define INT_MIN (-INT_MAX - 1)
#define UINT_MAX (~0U)
#define LONG_MAX ((long)(~0UL>>1))
#define LONG_MIN (-LONG_MAX - 1)
#define ULONG_MAX (~0UL)
#define LLONG_MAX ((long long)(~0ULL>>1))
#define LLONG_MIN (-LLONG_MAX - 1)
#define ULLONG_MAX (~0ULL)
#define STACK_MAGIC 0xdeadbeef
#define ALIGN(x,a) __ALIGN_MASK(x,(typeof(x))(a)-1)
#define __ALIGN_MASK(x,mask) (((x)+(mask))&~(mask))
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
#define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
/**
* upper_32_bits - return bits 32-63 of a number
* @n: the number we're accessing
*
* A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
* the "right shift count >= width of type" warning when that quantity is
* 32-bits.
*/
#define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
#define KERN_EMERG "<0>" /* system is unusable */
#define KERN_ALERT "<1>" /* action must be taken immediately */
#define KERN_CRIT "<2>" /* critical conditions */
#define KERN_ERR "<3>" /* error conditions */
#define KERN_WARNING "<4>" /* warning conditions */
#define KERN_NOTICE "<5>" /* normal but significant condition */
#define KERN_INFO "<6>" /* informational */
#define KERN_DEBUG "<7>" /* debug-level messages */
extern int console_printk[];
#define console_loglevel (console_printk[0])
#define default_message_loglevel (console_printk[1])
#define minimum_console_loglevel (console_printk[2])
#define default_console_loglevel (console_printk[3])
struct completion;
struct pt_regs;
struct user;
/**
* might_sleep - annotation for functions that can sleep
*
* this macro will print a stack trace if it is executed in an atomic
* context (spinlock, irq-handler, ...).
*
* This is a useful debugging help to be able to catch problems early and not
* be bitten later when the calling function happens to sleep when it is not
* supposed to.
*/
#ifdef CONFIG_PREEMPT_VOLUNTARY
extern int cond_resched(void);
# define might_resched() cond_resched()
#else
# define might_resched() do { } while (0)
#endif
#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
void __might_sleep(char *file, int line);
# define might_sleep() \
do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
#else
# define might_sleep() do { might_resched(); } while (0)
#endif
#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
#define abs(x) ({ \
int __x = (x); \
(__x < 0) ? -__x : __x; \
})
extern struct atomic_notifier_head panic_notifier_list;
extern long (*panic_blink)(long time);
NORET_TYPE void panic(const char * fmt, ...)
__attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
extern void oops_enter(void);
extern void oops_exit(void);
extern int oops_may_print(void);
fastcall NORET_TYPE void do_exit(long error_code)
ATTRIB_NORET;
NORET_TYPE void complete_and_exit(struct completion *, long)
ATTRIB_NORET;
extern unsigned long simple_strtoul(const char *,char **,unsigned int);
extern long simple_strtol(const char *,char **,unsigned int);
extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
extern long long simple_strtoll(const char *,char **,unsigned int);
extern int sprintf(char * buf, const char * fmt, ...)
__attribute__ ((format (printf, 2, 3)));
extern int vsprintf(char *buf, const char *, va_list)
__attribute__ ((format (printf, 2, 0)));
extern int snprintf(char * buf, size_t size, const char * fmt, ...)
__attribute__ ((format (printf, 3, 4)));
extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
__attribute__ ((format (printf, 3, 0)));
extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
__attribute__ ((format (printf, 3, 4)));
extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
__attribute__ ((format (printf, 3, 0)));
extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
__attribute__ ((format (printf, 2, 3)));
extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
extern int sscanf(const char *, const char *, ...)
__attribute__ ((format (scanf, 2, 3)));
extern int vsscanf(const char *, const char *, va_list)
__attribute__ ((format (scanf, 2, 0)));
extern int get_option(char **str, int *pint);
extern char *get_options(const char *str, int nints, int *ints);
extern unsigned long long memparse(char *ptr, char **retptr);
extern int core_kernel_text(unsigned long addr);
extern int __kernel_text_address(unsigned long addr);
extern int kernel_text_address(unsigned long addr);
struct pid;
extern struct pid *session_of_pgrp(struct pid *pgrp);
extern void dump_thread(struct pt_regs *regs, struct user *dump);
#ifdef CONFIG_PRINTK
asmlinkage int vprintk(const char *fmt, va_list args)
__attribute__ ((format (printf, 1, 0)));
asmlinkage int printk(const char * fmt, ...)
__attribute__ ((format (printf, 1, 2))) __cold;
#else
static inline int vprintk(const char *s, va_list args)
__attribute__ ((format (printf, 1, 0)));
static inline int vprintk(const char *s, va_list args) { return 0; }
static inline int printk(const char *s, ...)
__attribute__ ((format (printf, 1, 2)));
static inline int __cold printk(const char *s, ...) { return 0; }
#endif
unsigned long int_sqrt(unsigned long);
extern int printk_ratelimit(void);
extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
unsigned int interval_msec);
static inline void console_silent(void)
{
console_loglevel = 0;
}
static inline void console_verbose(void)
{
if (console_loglevel)
console_loglevel = 15;
}
extern void bust_spinlocks(int yes);
extern void wake_up_klogd(void);
extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
extern int panic_timeout;
extern int panic_on_oops;
extern int panic_on_unrecovered_nmi;
extern int tainted;
extern const char *print_tainted(void);
extern void add_taint(unsigned);
/* Values used for system_state */
extern enum system_states {
SYSTEM_BOOTING,
SYSTEM_RUNNING,
SYSTEM_HALT,
SYSTEM_POWER_OFF,
SYSTEM_RESTART,
SYSTEM_SUSPEND_DISK,
} system_state;
#define TAINT_PROPRIETARY_MODULE (1<<0)
#define TAINT_FORCED_MODULE (1<<1)
#define TAINT_UNSAFE_SMP (1<<2)
#define TAINT_FORCED_RMMOD (1<<3)
#define TAINT_MACHINE_CHECK (1<<4)
#define TAINT_BAD_PAGE (1<<5)
#define TAINT_USER (1<<6)
#define TAINT_DIE (1<<7)
extern void dump_stack(void) __cold;
enum {
DUMP_PREFIX_NONE,
DUMP_PREFIX_ADDRESS,
DUMP_PREFIX_OFFSET
};
extern void hex_dump_to_buffer(const void *buf, size_t len,
int rowsize, int groupsize,
char *linebuf, size_t linebuflen, bool ascii);
extern void print_hex_dump(const char *level, const char *prefix_str,
int prefix_type, int rowsize, int groupsize,
void *buf, size_t len, bool ascii);
extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
void *buf, size_t len);
#define hex_asc(x) "0123456789abcdef"[x]
#ifdef DEBUG
/* If you are writing a driver, please use dev_dbg instead */
#define pr_debug(fmt,arg...) \
printk(KERN_DEBUG fmt,##arg)
#else
static inline int __attribute__ ((format (printf, 1, 2))) pr_debug(const char * fmt, ...)
{
return 0;
}
#endif
#define pr_info(fmt,arg...) \
printk(KERN_INFO fmt,##arg)
/*
* Display an IP address in readable format.
*/
#define NIPQUAD(addr) \
((unsigned char *)&addr)[0], \
((unsigned char *)&addr)[1], \
((unsigned char *)&addr)[2], \
((unsigned char *)&addr)[3]
#define NIPQUAD_FMT "%u.%u.%u.%u"
#define NIP6(addr) \
ntohs((addr).s6_addr16[0]), \
ntohs((addr).s6_addr16[1]), \
ntohs((addr).s6_addr16[2]), \
ntohs((addr).s6_addr16[3]), \
ntohs((addr).s6_addr16[4]), \
ntohs((addr).s6_addr16[5]), \
ntohs((addr).s6_addr16[6]), \
ntohs((addr).s6_addr16[7])
#define NIP6_FMT "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
#define NIP6_SEQFMT "%04x%04x%04x%04x%04x%04x%04x%04x"
#if defined(__LITTLE_ENDIAN)
#define HIPQUAD(addr) \
((unsigned char *)&addr)[3], \
((unsigned char *)&addr)[2], \
((unsigned char *)&addr)[1], \
((unsigned char *)&addr)[0]
#elif defined(__BIG_ENDIAN)
#define HIPQUAD NIPQUAD
#else
#error "Please fix asm/byteorder.h"
#endif /* __LITTLE_ENDIAN */
/*
* min()/max() macros that also do
* strict type-checking.. See the
* "unnecessary" pointer comparison.
*/
#define min(x,y) ({ \
typeof(x) _x = (x); \
typeof(y) _y = (y); \
(void) (&_x == &_y); \
_x < _y ? _x : _y; })
#define max(x,y) ({ \
typeof(x) _x = (x); \
typeof(y) _y = (y); \
(void) (&_x == &_y); \
_x > _y ? _x : _y; })
/*
* ..and if you can't take the strict
* types, you can specify one yourself.
*
* Or not use min/max at all, of course.
*/
#define min_t(type,x,y) \
({ type __x = (x); type __y = (y); __x < __y ? __x: __y; })
#define max_t(type,x,y) \
({ type __x = (x); type __y = (y); __x > __y ? __x: __y; })
/**
* container_of - cast a member of a structure out to the containing structure
* @ptr: the pointer to the member.
* @type: the type of the container struct this is embedded in.
* @member: the name of the member within the struct.
*
*/
#define container_of(ptr, type, member) ({ \
const typeof( ((type *)0)->member ) *__mptr = (ptr); \
(type *)( (char *)__mptr - offsetof(type,member) );})
/*
* Check at compile time that something is of a particular type.
* Always evaluates to 1 so you may use it easily in comparisons.
*/
#define typecheck(type,x) \
({ type __dummy; \
typeof(x) __dummy2; \
(void)(&__dummy == &__dummy2); \
1; \
})
/*
* Check at compile time that 'function' is a certain type, or is a pointer
* to that type (needs to use typedef for the function type.)
*/
#define typecheck_fn(type,function) \
({ typeof(type) __tmp = function; \
(void)__tmp; \
})
struct sysinfo;
extern int do_sysinfo(struct sysinfo *info);
#endif /* __KERNEL__ */
#define SI_LOAD_SHIFT 16
struct sysinfo {
long uptime; /* Seconds since boot */
unsigned long loads[3]; /* 1, 5, and 15 minute load averages */
unsigned long totalram; /* Total usable main memory size */
unsigned long freeram; /* Available memory size */
unsigned long sharedram; /* Amount of shared memory */
unsigned long bufferram; /* Memory used by buffers */
unsigned long totalswap; /* Total swap space size */
unsigned long freeswap; /* swap space still available */
unsigned short procs; /* Number of current processes */
unsigned short pad; /* explicit padding for m68k */
unsigned long totalhigh; /* Total high memory size */
unsigned long freehigh; /* Available high memory size */
unsigned int mem_unit; /* Memory unit size in bytes */
char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
};
/* Force a compilation error if condition is true */
#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
/* Force a compilation error if condition is true, but also produce a
result (of value 0 and type size_t), so the expression can be used
e.g. in a structure initializer (or where-ever else comma expressions
aren't permitted). */
#define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
/* Trap pasters of __FUNCTION__ at compile-time */
#define __FUNCTION__ (__func__)
/* This helps us to avoid #ifdef CONFIG_NUMA */
#ifdef CONFIG_NUMA
#define NUMA_BUILD 1
#else
#define NUMA_BUILD 0
#endif
#endif