#ifndef _LINUX_KERNEL_H #define _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) #ifndef SIZE_MAX #define SIZE_MAX (~(size_t)0) #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)) #define STACK_MAGIC 0xdeadbeef #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x)) #define ALIGN(x,a) __ALIGN_MASK((x),(typeof(x))(a)-1) #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)) #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)); \ } \ ) /** * 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) );}) #endif