include/linux/kernel.h

#ifndef _LINUX_KERNEL_H
#define _LINUX_KERNEL_H

#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 <linux/typecheck.h>
#include <linux/printk.h>
#include <linux/dynamic_debug.h>
#include <asm/byteorder.h>
#include <uapi/linux/kernel.h>

#define USHRT_MAX ((u16)(~0U))
#define SHRT_MAX ((s16)(USHRT_MAX>>1))
#define SHRT_MIN ((s16)(-SHRT_MAX - 1))
#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 SIZE_MAX (~(size_t)0)

#define STACK_MAGIC 0xdeadbeef

#define REPEAT_BYTE(x) ((~0ul / 0xff) * (x))

#define ALIGN(x, a)  __ALIGN_KERNEL((x), (a))
#define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask))
#define PTR_ALIGN(p, a)  ((typeof(p))ALIGN((unsigned long)(p), (a)))
#define IS_ALIGNED(x, a)  (((x) & ((typeof(x))(a) - 1)) == 0)

#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))

/*
 * This looks more complex than it should be. But we need to
 * get the type for the ~ right in round_down (it needs to be
 * as wide as the result!), and we want to evaluate the macro
 * arguments just once each.
 */
#define __round_mask(x, y) ((__typeof__(x))((y)-1))
#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
#define round_down(x, y) ((x) & ~__round_mask(x, y))

#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
#define DIV_ROUND_UP_ULL(ll,d) \
 ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; })

#if BITS_PER_LONG == 32
# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
#else
# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
#endif

/* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
#define roundup(x, y) (     \
{       \
 const typeof(y) __y = y;   \
 (((x) + (__y - 1)) / __y) * __y;  \
}       \
)
#define rounddown(x, y) (    \
{       \
 typeof(x) __x = (x);    \
 __x - (__x % (y));    \
}       \
)

/*
 * Divide positive or negative dividend by positive divisor and round
 * to closest integer. Result is undefined for negative divisors and
 * for negative dividends if the divisor variable type is unsigned.
 */
#define DIV_ROUND_CLOSEST(x, divisor)(   \
{       \
 typeof(x) __x = x;    \
 typeof(divisor) __d = divisor;   \
 (((typeof(x))-1) > 0 ||    \
  ((typeof(divisor))-1) > 0 || (__x) > 0) ? \
  (((__x) + ((__d) / 2)) / (__d)) : \
  (((__x) - ((__d) / 2)) / (__d)); \
}       \
)

/*
 * Multiplies an integer by a fraction, while avoiding unnecessary
 * overflow or loss of precision.
 */
#define mult_frac(x, numer, denom)(   \
{       \
 typeof(x) quot = (x) / (denom);   \
 typeof(x) rem  = (x) % (denom);   \
 (quot * (numer)) + ((rem * (numer)) / (denom)); \
}       \
)

#define _RET_IP_  (unsigned long)__builtin_return_address(0)
#define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })

#ifdef CONFIG_LBDAF
# include <asm/div64.h>
# define sector_div(a, b) do_div(a, b)
#else
# define sector_div(n, b)( \
{ \
 int _res; \
 _res = (n) % (b); \
 (n) /= (b); \
 _res; \
} \
)
#endif

/**
 * 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))

/**
 * lower_32_bits - return bits 0-31 of a number
 * @n: the number we're accessing
 */
#define lower_32_bits(n) ((u32)(n))

struct completion;
struct pt_regs;
struct user;

#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_ATOMIC_SLEEP
  void __might_sleep(const char *file, int line, int preempt_offset);
/**
 * 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.
 */
# define might_sleep() \
 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
#else
  static inline void __might_sleep(const char *file, int line,
       int preempt_offset) { }
# define might_sleep() do { might_resched(); } while (0)
#endif

#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)

/*
 * abs() handles unsigned and signed longs, ints, shorts and chars.  For all
 * input types abs() returns a signed long.
 * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64()
 * for those.
 */
#define abs(x) ({      \
  long ret;     \
  if (sizeof(x) == sizeof(long)) {  \
   long __x = (x);    \
   ret = (__x < 0) ? -__x : __x;  \
  } else {     \
   int __x = (x);    \
   ret = (__x < 0) ? -__x : __x;  \
  }      \
  ret;      \
 })

#define abs64(x) ({    \
  s64 __x = (x);   \
  (__x < 0) ? -__x : __x;  \
 })

#ifdef CONFIG_PROVE_LOCKING
void might_fault(void);
#else
static inline void might_fault(void)
{
 might_sleep();
}
#endif

extern struct atomic_notifier_head panic_notifier_list;
extern long (*panic_blink)(int state);
__printf(1, 2)
void panic(const char *fmt, ...)
 __noreturn __cold;
extern void oops_enter(void);
extern void oops_exit(void);
void print_oops_end_marker(void);
extern int oops_may_print(void);
void do_exit(long error_code)
 __noreturn;
void complete_and_exit(struct completion *, long)
 __noreturn;

/* Internal, do not use. */
int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
int __must_check _kstrtol(const char *s, unsigned int base, long *res);

int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
int __must_check kstrtoll(const char *s, unsigned int base, long long *res);

/**
 * kstrtoul - convert a string to an unsigned long
 * @s: The start of the string. The string must be null-terminated, and may also
 *  include a single newline before its terminating null. The first character
 *  may also be a plus sign, but not a minus sign.
 * @base: The number base to use. The maximum supported base is 16. If base is
 *  given as 0, then the base of the string is automatically detected with the
 *  conventional semantics - If it begins with 0x the number will be parsed as a
 *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
 *  parsed as an octal number. Otherwise it will be parsed as a decimal.
 * @res: Where to write the result of the conversion on success.
 *
 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
 * Used as a replacement for the obsolete simple_strtoull. Return code must
 * be checked.
*/
static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
{
 /*
  * We want to shortcut function call, but
  * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
  */
 if (sizeof(unsigned long) == sizeof(unsigned long long) &&
     __alignof__(unsigned long) == __alignof__(unsigned long long))
  return kstrtoull(s, base, (unsigned long long *)res);
 else
  return _kstrtoul(s, base, res);
}

/**
 * kstrtol - convert a string to a long
 * @s: The start of the string. The string must be null-terminated, and may also
 *  include a single newline before its terminating null. The first character
 *  may also be a plus sign or a minus sign.
 * @base: The number base to use. The maximum supported base is 16. If base is
 *  given as 0, then the base of the string is automatically detected with the
 *  conventional semantics - If it begins with 0x the number will be parsed as a
 *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
 *  parsed as an octal number. Otherwise it will be parsed as a decimal.
 * @res: Where to write the result of the conversion on success.
 *
 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
 * Used as a replacement for the obsolete simple_strtoull. Return code must
 * be checked.
 */
static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
{
 /*
  * We want to shortcut function call, but
  * __builtin_types_compatible_p(long, long long) = 0.
  */
 if (sizeof(long) == sizeof(long long) &&
     __alignof__(long) == __alignof__(long long))
  return kstrtoll(s, base, (long long *)res);
 else
  return _kstrtol(s, base, res);
}

int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
int __must_check kstrtoint(const char *s, unsigned int base, int *res);

static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
{
 return kstrtoull(s, base, res);
}

static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
{
 return kstrtoll(s, base, res);
}

static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
{
 return kstrtouint(s, base, res);
}

static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
{
 return kstrtoint(s, base, res);
}

int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);

int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);

static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
{
 return kstrtoull_from_user(s, count, base, res);
}

static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
{
 return kstrtoll_from_user(s, count, base, res);
}

static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
{
 return kstrtouint_from_user(s, count, base, res);
}

static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
{
 return kstrtoint_from_user(s, count, base, res);
}

/* Obsolete, do not use.  Use kstrto<foo> instead */

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);
#define strict_strtoul kstrtoul
#define strict_strtol kstrtol
#define strict_strtoull kstrtoull
#define strict_strtoll kstrtoll

extern int num_to_str(char *buf, int size, unsigned long long num);

/* lib/printf utilities */

extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
extern __printf(3, 4)
int snprintf(char *buf, size_t size, const char *fmt, ...);
extern __printf(3, 0)
int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
extern __printf(3, 4)
int scnprintf(char *buf, size_t size, const char *fmt, ...);
extern __printf(3, 0)
int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
extern __printf(2, 3)
char *kasprintf(gfp_t gfp, const char *fmt, ...);
extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);

extern __scanf(2, 3)
int sscanf(const char *, const char *, ...);
extern __scanf(2, 0)
int vsscanf(const char *, const char *, va_list);

extern int get_option(char **str, int *pint);
extern char *get_options(const char *str, int nints, int *ints);
extern unsigned long long memparse(const char *ptr, char **retptr);

extern int core_kernel_text(unsigned long addr);
extern int core_kernel_data(unsigned long addr);
extern int __kernel_text_address(unsigned long addr);
extern int kernel_text_address(unsigned long addr);
extern int func_ptr_is_kernel_text(void *ptr);

struct pid;
extern struct pid *session_of_pgrp(struct pid *pgrp);

unsigned long int_sqrt(unsigned long);

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 panic_on_io_nmi;
extern int sysctl_panic_on_stackoverflow;
extern const char *print_tainted(void);
extern void add_taint(unsigned flag);
extern int test_taint(unsigned flag);
extern unsigned long get_taint(void);
extern int root_mountflags;

extern bool early_boot_irqs_disabled;

/* Values used for system_state */
extern enum system_states {
 SYSTEM_BOOTING,
 SYSTEM_RUNNING,
 SYSTEM_HALT,
 SYSTEM_POWER_OFF,
 SYSTEM_RESTART,
} system_state;

#define TAINT_PROPRIETARY_MODULE 0
#define TAINT_FORCED_MODULE  1
#define TAINT_UNSAFE_SMP  2
#define TAINT_FORCED_RMMOD  3
#define TAINT_MACHINE_CHECK  4
#define TAINT_BAD_PAGE   5
#define TAINT_USER   6
#define TAINT_DIE   7
#define TAINT_OVERRIDDEN_ACPI_TABLE 8
#define TAINT_WARN   9
#define TAINT_CRAP   10
#define TAINT_FIRMWARE_WORKAROUND 11
#define TAINT_OOT_MODULE  12

extern const char hex_asc[];
#define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]

static inline char *hex_byte_pack(char *buf, u8 byte)
{
 *buf++ = hex_asc_hi(byte);
 *buf++ = hex_asc_lo(byte);
 return buf;
}

static inline char * __deprecated pack_hex_byte(char *buf, u8 byte)
{
 return hex_byte_pack(buf, byte);
}

extern int hex_to_bin(char ch);
extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);

/*
 * General tracing related utility functions - trace_printk(),
 * tracing_on/tracing_off and tracing_start()/tracing_stop
 *
 * Use tracing_on/tracing_off when you want to quickly turn on or off
 * tracing. It simply enables or disables the recording of the trace events.
 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
 * file, which gives a means for the kernel and userspace to interact.
 * Place a tracing_off() in the kernel where you want tracing to end.
 * From user space, examine the trace, and then echo 1 > tracing_on
 * to continue tracing.
 *
 * tracing_stop/tracing_start has slightly more overhead. It is used
 * by things like suspend to ram where disabling the recording of the
 * trace is not enough, but tracing must actually stop because things
 * like calling smp_processor_id() may crash the system.
 *
 * Most likely, you want to use tracing_on/tracing_off.
 */
#ifdef CONFIG_RING_BUFFER
/* trace_off_permanent stops recording with no way to bring it back */
void tracing_off_permanent(void);
#else
static inline void tracing_off_permanent(void) { }
#endif

enum ftrace_dump_mode {
 DUMP_NONE,
 DUMP_ALL,
 DUMP_ORIG,
};

#ifdef CONFIG_TRACING
void tracing_on(void);
void tracing_off(void);
int tracing_is_on(void);

extern void tracing_start(void);
extern void tracing_stop(void);
extern void ftrace_off_permanent(void);

static inline __printf(1, 2)
void ____trace_printk_check_format(const char *fmt, ...)
{
}
#define __trace_printk_check_format(fmt, args...)   \
do {         \
 if (0)        \
  ____trace_printk_check_format(fmt, ##args);  \
} while (0)

/**
 * trace_printk - printf formatting in the ftrace buffer
 * @fmt: the printf format for printing
 *
 * Note: __trace_printk is an internal function for trace_printk and
 *       the @ip is passed in via the trace_printk macro.
 *
 * This function allows a kernel developer to debug fast path sections
 * that printk is not appropriate for. By scattering in various
 * printk like tracing in the code, a developer can quickly see
 * where problems are occurring.
 *
 * This is intended as a debugging tool for the developer only.
 * Please refrain from leaving trace_printks scattered around in
 * your code.
 */

#define trace_printk(fmt, args...)     \
do {         \
 static const char *trace_printk_fmt    \
  __attribute__((section("__trace_printk_fmt"))) = \
  __builtin_constant_p(fmt) ? fmt : NULL;   \
         \
 __trace_printk_check_format(fmt, ##args);   \
         \
 if (__builtin_constant_p(fmt))     \
  __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
 else        \
  __trace_printk(_THIS_IP_, fmt, ##args);   \
} while (0)

extern __printf(2, 3)
int __trace_bprintk(unsigned long ip, const char *fmt, ...);

extern __printf(2, 3)
int __trace_printk(unsigned long ip, const char *fmt, ...);

extern void trace_dump_stack(void);

/*
 * The double __builtin_constant_p is because gcc will give us an error
 * if we try to allocate the static variable to fmt if it is not a
 * constant. Even with the outer if statement.
 */
#define ftrace_vprintk(fmt, vargs)     \
do {         \
 if (__builtin_constant_p(fmt)) {    \
  static const char *trace_printk_fmt   \
    __attribute__((section("__trace_printk_fmt"))) = \
   __builtin_constant_p(fmt) ? fmt : NULL;  \
         \
  __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
 } else        \
  __ftrace_vprintk(_THIS_IP_, fmt, vargs);  \
} while (0)

extern int
__ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);

extern int
__ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);

extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
#else
static inline void tracing_start(void) { }
static inline void tracing_stop(void) { }
static inline void ftrace_off_permanent(void) { }
static inline void trace_dump_stack(void) { }

static inline void tracing_on(void) { }
static inline void tracing_off(void) { }
static inline int tracing_is_on(void) { return 0; }

static inline __printf(1, 2)
int trace_printk(const char *fmt, ...)
{
 return 0;
}
static inline int
ftrace_vprintk(const char *fmt, va_list ap)
{
 return 0;
}
static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
#endif /* CONFIG_TRACING */

/*
 * min()/max()/clamp() macros that also do
 * strict type-checking.. See the
 * "unnecessary" pointer comparison.
 */
#define min(x, y) ({    \
 typeof(x) _min1 = (x);   \
 typeof(y) _min2 = (y);   \
 (void) (&_min1 == &_min2);  \
 _min1 < _min2 ? _min1 : _min2; })

#define max(x, y) ({    \
 typeof(x) _max1 = (x);   \
 typeof(y) _max2 = (y);   \
 (void) (&_max1 == &_max2);  \
 _max1 > _max2 ? _max1 : _max2; })

#define min3(x, y, z) ({   \
 typeof(x) _min1 = (x);   \
 typeof(y) _min2 = (y);   \
 typeof(z) _min3 = (z);   \
 (void) (&_min1 == &_min2);  \
 (void) (&_min1 == &_min3);  \
 _min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \
  (_min2 < _min3 ? _min2 : _min3); })

#define max3(x, y, z) ({   \
 typeof(x) _max1 = (x);   \
 typeof(y) _max2 = (y);   \
 typeof(z) _max3 = (z);   \
 (void) (&_max1 == &_max2);  \
 (void) (&_max1 == &_max3);  \
 _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \
  (_max2 > _max3 ? _max2 : _max3); })

/**
 * min_not_zero - return the minimum that is _not_ zero, unless both are zero
 * @x: value1
 * @y: value2
 */
#define min_not_zero(x, y) ({   \
 typeof(x) __x = (x);   \
 typeof(y) __y = (y);   \
 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })

/**
 * clamp - return a value clamped to a given range with strict typechecking
 * @val: current value
 * @min: minimum allowable value
 * @max: maximum allowable value
 *
 * This macro does strict typechecking of min/max to make sure they are of the
 * same type as val.  See the unnecessary pointer comparisons.
 */
#define clamp(val, min, max) ({   \
 typeof(val) __val = (val);  \
 typeof(min) __min = (min);  \
 typeof(max) __max = (max);  \
 (void) (&__val == &__min);  \
 (void) (&__val == &__max);  \
 __val = __val < __min ? __min: __val; \
 __val > __max ? __max: __val; })

/*
 * ..and if you can't take the strict
 * types, you can specify one yourself.
 *
 * Or not use min/max/clamp at all, of course.
 */
#define min_t(type, x, y) ({   \
 type __min1 = (x);   \
 type __min2 = (y);   \
 __min1 < __min2 ? __min1: __min2; })

#define max_t(type, x, y) ({   \
 type __max1 = (x);   \
 type __max2 = (y);   \
 __max1 > __max2 ? __max1: __max2; })

/**
 * clamp_t - return a value clamped to a given range using a given type
 * @type: the type of variable to use
 * @val: current value
 * @min: minimum allowable value
 * @max: maximum allowable value
 *
 * This macro does no typechecking and uses temporary variables of type
 * 'type' to make all the comparisons.
 */
#define clamp_t(type, val, min, max) ({  \
 type __val = (val);   \
 type __min = (min);   \
 type __max = (max);   \
 __val = __val < __min ? __min: __val; \
 __val > __max ? __max: __val; })

/**
 * clamp_val - return a value clamped to a given range using val's type
 * @val: current value
 * @min: minimum allowable value
 * @max: maximum allowable value
 *
 * This macro does no typechecking and uses temporary variables of whatever
 * type the input argument 'val' is.  This is useful when val is an unsigned
 * type and min and max are literals that will otherwise be assigned a signed
 * integer type.
 */
#define clamp_val(val, min, max) ({  \
 typeof(val) __val = (val);  \
 typeof(val) __min = (min);  \
 typeof(val) __max = (max);  \
 __val = __val < __min ? __min: __val; \
 __val > __max ? __max: __val; })

/*
 * swap - swap value of @a and @b
 */
#define swap(a, b) \
 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)

/**
 * 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) );})

/* Trap pasters of __FUNCTION__ at compile-time */
#define __FUNCTION__ (__func__)

/* This helps us to avoid #ifdef CONFIG_SYMBOL_PREFIX */
#ifdef CONFIG_SYMBOL_PREFIX
#define SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
#else
#define SYMBOL_PREFIX ""
#endif

/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
#endif

extern int do_sysinfo(struct sysinfo *info);

#endif