#ifndef _LINUX_KERNEL_H
#define _LINUX_KERNEL_H

#include <linux/types.h>
#include <linux/printk.h> /* for printf/pr_* utilities */

#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)
#ifndef SIZE_MAX
#define SIZE_MAX        (~(size_t)0)
#endif
#ifndef SSIZE_MAX
#define SSIZE_MAX       ((ssize_t)(SIZE_MAX >> 1))
#endif

#define U8_MAX          ((u8)~0U)
#define S8_MAX          ((s8)(U8_MAX>>1))
#define S8_MIN          ((s8)(-S8_MAX - 1))
#define U16_MAX         ((u16)~0U)
#define S16_MAX         ((s16)(U16_MAX>>1))
#define S16_MIN         ((s16)(-S16_MAX - 1))
#define U32_MAX         ((u32)~0U)
#define S32_MAX         ((s32)(U32_MAX>>1))
#define S32_MIN         ((s32)(-S32_MAX - 1))
#define U64_MAX         ((u64)~0ULL)
#define S64_MAX         ((s64)(U64_MAX>>1))
#define S64_MIN         ((s64)(-S64_MAX - 1))

/* Aliases defined by stdint.h */
#define UINT32_MAX      U32_MAX
#define UINT64_MAX      U64_MAX

#define INT32_MAX       S32_MAX

#define STACK_MAGIC     0xdeadbeef

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

#define ALIGN(x,a)              __ALIGN_MASK((x),(typeof(x))(a)-1)
#define ALIGN_DOWN(x, a)        ALIGN((x) - ((a) - 1), (a))
#define __ALIGN_MASK(x,mask)    (((x)+(mask))&~(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(x) (sizeof(x) / sizeof((x)[0]))

/*
 * 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_DOWN_ULL(ll, d) \
        ({ unsigned long long _tmp = (ll); do_div(_tmp, d); _tmp; })

#define DIV_ROUND_UP_ULL(ll, d)         DIV_ROUND_DOWN_ULL((ll) + (d) - 1, (d))

#define ROUND(a, b)             (((a) + (b) - 1) & ~((b) - 1))

#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));        \
}                                                       \
)
/*
 * Same as above but for u64 dividends. divisor must be a 32-bit
 * number.
 */
#define DIV_ROUND_CLOSEST_ULL(x, divisor)(              \
{                                                       \
        typeof(divisor) __d = divisor;                  \
        unsigned long long _tmp = (x) + (__d) / 2;      \
        do_div(_tmp, __d);                              \
        _tmp;                                           \
}                                                       \
)

/*
 * 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)); \
}                                                       \
)

/**
 * 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))

/*
 * 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;         \
        })

/*
 * 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) min((typeof(x))min(x, y), z)
#define max3(x, y, z) max((typeof(x))max(x, y), z)

/**
 * 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
 * @lo: lowest allowable value
 * @hi: highest allowable value
 *
 * This macro does strict typechecking of lo/hi to make sure they are of the
 * same type as val.  See the unnecessary pointer comparisons.
 */
#define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)

/*
 * ..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
 * @lo: minimum allowable value
 * @hi: 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, lo, hi) min_t(type, max_t(type, val, lo), hi)

/**
 * clamp_val - return a value clamped to a given range using val's type
 * @val: current value
 * @lo: minimum allowable value
 * @hi: 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, lo, hi) clamp_t(typeof(val), val, lo, hi)


/*
 * 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) );})

/*
 * check_member() - Check the offset of a structure member
 *
 * @structure:  Name of structure (e.g. global_data)
 * @member:     Name of member (e.g. baudrate)
 * @offset:     Expected offset in bytes
 */
#define check_member(structure, member, offset) _Static_assert( \
        offsetof(struct structure, member) == (offset), \
        "`struct " #structure "` offset for `" #member "` is not " #offset)

#endif