1cba1da49SMasahiro Yamada #ifndef _LINUX_KERNEL_H 2cba1da49SMasahiro Yamada #define _LINUX_KERNEL_H 3cba1da49SMasahiro Yamada 4cba1da49SMasahiro Yamada 5cba1da49SMasahiro Yamada #include <linux/types.h> 6cba1da49SMasahiro Yamada 748c7ea39SMasahiro Yamada #define USHRT_MAX ((u16)(~0U)) 848c7ea39SMasahiro Yamada #define SHRT_MAX ((s16)(USHRT_MAX>>1)) 948c7ea39SMasahiro Yamada #define SHRT_MIN ((s16)(-SHRT_MAX - 1)) 10cba1da49SMasahiro Yamada #define INT_MAX ((int)(~0U>>1)) 11cba1da49SMasahiro Yamada #define INT_MIN (-INT_MAX - 1) 1248c7ea39SMasahiro Yamada #define UINT_MAX (~0U) 1348c7ea39SMasahiro Yamada #define LONG_MAX ((long)(~0UL>>1)) 1448c7ea39SMasahiro Yamada #define LONG_MIN (-LONG_MAX - 1) 1548c7ea39SMasahiro Yamada #define ULONG_MAX (~0UL) 16cba1da49SMasahiro Yamada #define LLONG_MAX ((long long)(~0ULL>>1)) 1748c7ea39SMasahiro Yamada #define LLONG_MIN (-LLONG_MAX - 1) 1848c7ea39SMasahiro Yamada #define ULLONG_MAX (~0ULL) 1948c7ea39SMasahiro Yamada #define SIZE_MAX (~(size_t)0) 20cba1da49SMasahiro Yamada 21cba1da49SMasahiro Yamada #define U8_MAX ((u8)~0U) 2248c7ea39SMasahiro Yamada #define S8_MAX ((s8)(U8_MAX>>1)) 2348c7ea39SMasahiro Yamada #define S8_MIN ((s8)(-S8_MAX - 1)) 2448c7ea39SMasahiro Yamada #define U16_MAX ((u16)~0U) 2548c7ea39SMasahiro Yamada #define S16_MAX ((s16)(U16_MAX>>1)) 2648c7ea39SMasahiro Yamada #define S16_MIN ((s16)(-S16_MAX - 1)) 27cba1da49SMasahiro Yamada #define U32_MAX ((u32)~0U) 2848c7ea39SMasahiro Yamada #define S32_MAX ((s32)(U32_MAX>>1)) 2948c7ea39SMasahiro Yamada #define S32_MIN ((s32)(-S32_MAX - 1)) 30cba1da49SMasahiro Yamada #define U64_MAX ((u64)~0ULL) 3148c7ea39SMasahiro Yamada #define S64_MAX ((s64)(U64_MAX>>1)) 3248c7ea39SMasahiro Yamada #define S64_MIN ((s64)(-S64_MAX - 1)) 3348c7ea39SMasahiro Yamada 3448c7ea39SMasahiro Yamada #define STACK_MAGIC 0xdeadbeef 3548c7ea39SMasahiro Yamada 3648c7ea39SMasahiro Yamada #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x)) 37cba1da49SMasahiro Yamada 38cba1da49SMasahiro Yamada #define ALIGN(x,a) __ALIGN_MASK((x),(typeof(x))(a)-1) 39cba1da49SMasahiro Yamada #define __ALIGN_MASK(x,mask) (((x)+(mask))&~(mask)) 4048c7ea39SMasahiro Yamada #define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a))) 4148c7ea39SMasahiro Yamada #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0) 42cba1da49SMasahiro Yamada 43cba1da49SMasahiro Yamada #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) 44cba1da49SMasahiro Yamada 45cba1da49SMasahiro Yamada /* 46cba1da49SMasahiro Yamada * This looks more complex than it should be. But we need to 47cba1da49SMasahiro Yamada * get the type for the ~ right in round_down (it needs to be 48cba1da49SMasahiro Yamada * as wide as the result!), and we want to evaluate the macro 49cba1da49SMasahiro Yamada * arguments just once each. 50cba1da49SMasahiro Yamada */ 51cba1da49SMasahiro Yamada #define __round_mask(x, y) ((__typeof__(x))((y)-1)) 52cba1da49SMasahiro Yamada #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1) 53cba1da49SMasahiro Yamada #define round_down(x, y) ((x) & ~__round_mask(x, y)) 54cba1da49SMasahiro Yamada 5548c7ea39SMasahiro Yamada #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f)) 56cba1da49SMasahiro Yamada #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d)) 57cba1da49SMasahiro Yamada 5848c7ea39SMasahiro Yamada #if BITS_PER_LONG == 32 5948c7ea39SMasahiro Yamada # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d) 6048c7ea39SMasahiro Yamada #else 6148c7ea39SMasahiro Yamada # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d) 6248c7ea39SMasahiro Yamada #endif 6348c7ea39SMasahiro Yamada 64*111396ccSMasahiro Yamada /* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */ 65*111396ccSMasahiro Yamada #define roundup(x, y) ( \ 66*111396ccSMasahiro Yamada { \ 67*111396ccSMasahiro Yamada const typeof(y) __y = y; \ 68*111396ccSMasahiro Yamada (((x) + (__y - 1)) / __y) * __y; \ 69*111396ccSMasahiro Yamada } \ 70*111396ccSMasahiro Yamada ) 7148c7ea39SMasahiro Yamada #define rounddown(x, y) ( \ 7248c7ea39SMasahiro Yamada { \ 7348c7ea39SMasahiro Yamada typeof(x) __x = (x); \ 7448c7ea39SMasahiro Yamada __x - (__x % (y)); \ 7548c7ea39SMasahiro Yamada } \ 7648c7ea39SMasahiro Yamada ) 7748c7ea39SMasahiro Yamada 78cba1da49SMasahiro Yamada /* 79cba1da49SMasahiro Yamada * Divide positive or negative dividend by positive divisor and round 80cba1da49SMasahiro Yamada * to closest integer. Result is undefined for negative divisors and 81cba1da49SMasahiro Yamada * for negative dividends if the divisor variable type is unsigned. 82cba1da49SMasahiro Yamada */ 83cba1da49SMasahiro Yamada #define DIV_ROUND_CLOSEST(x, divisor)( \ 84cba1da49SMasahiro Yamada { \ 85cba1da49SMasahiro Yamada typeof(x) __x = x; \ 86cba1da49SMasahiro Yamada typeof(divisor) __d = divisor; \ 87cba1da49SMasahiro Yamada (((typeof(x))-1) > 0 || \ 88cba1da49SMasahiro Yamada ((typeof(divisor))-1) > 0 || (__x) > 0) ? \ 89cba1da49SMasahiro Yamada (((__x) + ((__d) / 2)) / (__d)) : \ 90cba1da49SMasahiro Yamada (((__x) - ((__d) / 2)) / (__d)); \ 91cba1da49SMasahiro Yamada } \ 92cba1da49SMasahiro Yamada ) 93cba1da49SMasahiro Yamada 94cba1da49SMasahiro Yamada /* 95cba1da49SMasahiro Yamada * Multiplies an integer by a fraction, while avoiding unnecessary 96cba1da49SMasahiro Yamada * overflow or loss of precision. 97cba1da49SMasahiro Yamada */ 98cba1da49SMasahiro Yamada #define mult_frac(x, numer, denom)( \ 99cba1da49SMasahiro Yamada { \ 100cba1da49SMasahiro Yamada typeof(x) quot = (x) / (denom); \ 101cba1da49SMasahiro Yamada typeof(x) rem = (x) % (denom); \ 102cba1da49SMasahiro Yamada (quot * (numer)) + ((rem * (numer)) / (denom)); \ 103cba1da49SMasahiro Yamada } \ 104cba1da49SMasahiro Yamada ) 105cba1da49SMasahiro Yamada 106cba1da49SMasahiro Yamada /** 107cba1da49SMasahiro Yamada * upper_32_bits - return bits 32-63 of a number 108cba1da49SMasahiro Yamada * @n: the number we're accessing 109cba1da49SMasahiro Yamada * 110cba1da49SMasahiro Yamada * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress 111cba1da49SMasahiro Yamada * the "right shift count >= width of type" warning when that quantity is 112cba1da49SMasahiro Yamada * 32-bits. 113cba1da49SMasahiro Yamada */ 114cba1da49SMasahiro Yamada #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16)) 115cba1da49SMasahiro Yamada 116cba1da49SMasahiro Yamada /** 117cba1da49SMasahiro Yamada * lower_32_bits - return bits 0-31 of a number 118cba1da49SMasahiro Yamada * @n: the number we're accessing 119cba1da49SMasahiro Yamada */ 120cba1da49SMasahiro Yamada #define lower_32_bits(n) ((u32)(n)) 121cba1da49SMasahiro Yamada 122cba1da49SMasahiro Yamada /* 123cba1da49SMasahiro Yamada * abs() handles unsigned and signed longs, ints, shorts and chars. For all 124cba1da49SMasahiro Yamada * input types abs() returns a signed long. 125cba1da49SMasahiro Yamada * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64() 126cba1da49SMasahiro Yamada * for those. 127cba1da49SMasahiro Yamada */ 128cba1da49SMasahiro Yamada #define abs(x) ({ \ 129cba1da49SMasahiro Yamada long ret; \ 130cba1da49SMasahiro Yamada if (sizeof(x) == sizeof(long)) { \ 131cba1da49SMasahiro Yamada long __x = (x); \ 132cba1da49SMasahiro Yamada ret = (__x < 0) ? -__x : __x; \ 133cba1da49SMasahiro Yamada } else { \ 134cba1da49SMasahiro Yamada int __x = (x); \ 135cba1da49SMasahiro Yamada ret = (__x < 0) ? -__x : __x; \ 136cba1da49SMasahiro Yamada } \ 137cba1da49SMasahiro Yamada ret; \ 138cba1da49SMasahiro Yamada }) 139cba1da49SMasahiro Yamada 140cba1da49SMasahiro Yamada #define abs64(x) ({ \ 141cba1da49SMasahiro Yamada s64 __x = (x); \ 142cba1da49SMasahiro Yamada (__x < 0) ? -__x : __x; \ 143cba1da49SMasahiro Yamada }) 144cba1da49SMasahiro Yamada 145cba1da49SMasahiro Yamada /* 146cba1da49SMasahiro Yamada * min()/max()/clamp() macros that also do 147cba1da49SMasahiro Yamada * strict type-checking.. See the 148cba1da49SMasahiro Yamada * "unnecessary" pointer comparison. 149cba1da49SMasahiro Yamada */ 150cba1da49SMasahiro Yamada #define min(x, y) ({ \ 151cba1da49SMasahiro Yamada typeof(x) _min1 = (x); \ 152cba1da49SMasahiro Yamada typeof(y) _min2 = (y); \ 153cba1da49SMasahiro Yamada _min1 < _min2 ? _min1 : _min2; }) 154cba1da49SMasahiro Yamada 155cba1da49SMasahiro Yamada #define max(x, y) ({ \ 156cba1da49SMasahiro Yamada typeof(x) _max1 = (x); \ 157cba1da49SMasahiro Yamada typeof(y) _max2 = (y); \ 158cba1da49SMasahiro Yamada _max1 > _max2 ? _max1 : _max2; }) 159cba1da49SMasahiro Yamada 160cba1da49SMasahiro Yamada #define min3(x, y, z) ({ \ 161cba1da49SMasahiro Yamada typeof(x) _min1 = (x); \ 162cba1da49SMasahiro Yamada typeof(y) _min2 = (y); \ 163cba1da49SMasahiro Yamada typeof(z) _min3 = (z); \ 164cba1da49SMasahiro Yamada _min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \ 165cba1da49SMasahiro Yamada (_min2 < _min3 ? _min2 : _min3); }) 166cba1da49SMasahiro Yamada 167cba1da49SMasahiro Yamada #define max3(x, y, z) ({ \ 168cba1da49SMasahiro Yamada typeof(x) _max1 = (x); \ 169cba1da49SMasahiro Yamada typeof(y) _max2 = (y); \ 170cba1da49SMasahiro Yamada typeof(z) _max3 = (z); \ 171cba1da49SMasahiro Yamada _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \ 172cba1da49SMasahiro Yamada (_max2 > _max3 ? _max2 : _max3); }) 173cba1da49SMasahiro Yamada 17448c7ea39SMasahiro Yamada /** 17548c7ea39SMasahiro Yamada * min_not_zero - return the minimum that is _not_ zero, unless both are zero 17648c7ea39SMasahiro Yamada * @x: value1 17748c7ea39SMasahiro Yamada * @y: value2 17848c7ea39SMasahiro Yamada */ 17948c7ea39SMasahiro Yamada #define min_not_zero(x, y) ({ \ 18048c7ea39SMasahiro Yamada typeof(x) __x = (x); \ 18148c7ea39SMasahiro Yamada typeof(y) __y = (y); \ 18248c7ea39SMasahiro Yamada __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); }) 18348c7ea39SMasahiro Yamada 18448c7ea39SMasahiro Yamada /** 18548c7ea39SMasahiro Yamada * clamp - return a value clamped to a given range with strict typechecking 18648c7ea39SMasahiro Yamada * @val: current value 18748c7ea39SMasahiro Yamada * @lo: lowest allowable value 18848c7ea39SMasahiro Yamada * @hi: highest allowable value 18948c7ea39SMasahiro Yamada * 19048c7ea39SMasahiro Yamada * This macro does strict typechecking of lo/hi to make sure they are of the 19148c7ea39SMasahiro Yamada * same type as val. See the unnecessary pointer comparisons. 19248c7ea39SMasahiro Yamada */ 19348c7ea39SMasahiro Yamada #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) 19448c7ea39SMasahiro Yamada 195cba1da49SMasahiro Yamada /* 196cba1da49SMasahiro Yamada * ..and if you can't take the strict 197cba1da49SMasahiro Yamada * types, you can specify one yourself. 198cba1da49SMasahiro Yamada * 199cba1da49SMasahiro Yamada * Or not use min/max/clamp at all, of course. 200cba1da49SMasahiro Yamada */ 201cba1da49SMasahiro Yamada #define min_t(type, x, y) ({ \ 202cba1da49SMasahiro Yamada type __min1 = (x); \ 203cba1da49SMasahiro Yamada type __min2 = (y); \ 204cba1da49SMasahiro Yamada __min1 < __min2 ? __min1: __min2; }) 205cba1da49SMasahiro Yamada 206cba1da49SMasahiro Yamada #define max_t(type, x, y) ({ \ 207cba1da49SMasahiro Yamada type __max1 = (x); \ 208cba1da49SMasahiro Yamada type __max2 = (y); \ 209cba1da49SMasahiro Yamada __max1 > __max2 ? __max1: __max2; }) 210cba1da49SMasahiro Yamada 211cba1da49SMasahiro Yamada /** 21248c7ea39SMasahiro Yamada * clamp_t - return a value clamped to a given range using a given type 21348c7ea39SMasahiro Yamada * @type: the type of variable to use 21448c7ea39SMasahiro Yamada * @val: current value 21548c7ea39SMasahiro Yamada * @lo: minimum allowable value 21648c7ea39SMasahiro Yamada * @hi: maximum allowable value 21748c7ea39SMasahiro Yamada * 21848c7ea39SMasahiro Yamada * This macro does no typechecking and uses temporary variables of type 21948c7ea39SMasahiro Yamada * 'type' to make all the comparisons. 22048c7ea39SMasahiro Yamada */ 22148c7ea39SMasahiro Yamada #define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi) 22248c7ea39SMasahiro Yamada 22348c7ea39SMasahiro Yamada /** 22448c7ea39SMasahiro Yamada * clamp_val - return a value clamped to a given range using val's type 22548c7ea39SMasahiro Yamada * @val: current value 22648c7ea39SMasahiro Yamada * @lo: minimum allowable value 22748c7ea39SMasahiro Yamada * @hi: maximum allowable value 22848c7ea39SMasahiro Yamada * 22948c7ea39SMasahiro Yamada * This macro does no typechecking and uses temporary variables of whatever 23048c7ea39SMasahiro Yamada * type the input argument 'val' is. This is useful when val is an unsigned 23148c7ea39SMasahiro Yamada * type and min and max are literals that will otherwise be assigned a signed 23248c7ea39SMasahiro Yamada * integer type. 23348c7ea39SMasahiro Yamada */ 23448c7ea39SMasahiro Yamada #define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi) 23548c7ea39SMasahiro Yamada 23648c7ea39SMasahiro Yamada 23748c7ea39SMasahiro Yamada /* 23848c7ea39SMasahiro Yamada * swap - swap value of @a and @b 23948c7ea39SMasahiro Yamada */ 24048c7ea39SMasahiro Yamada #define swap(a, b) \ 24148c7ea39SMasahiro Yamada do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0) 24248c7ea39SMasahiro Yamada 24348c7ea39SMasahiro Yamada /** 244cba1da49SMasahiro Yamada * container_of - cast a member of a structure out to the containing structure 245cba1da49SMasahiro Yamada * @ptr: the pointer to the member. 246cba1da49SMasahiro Yamada * @type: the type of the container struct this is embedded in. 247cba1da49SMasahiro Yamada * @member: the name of the member within the struct. 248cba1da49SMasahiro Yamada * 249cba1da49SMasahiro Yamada */ 250cba1da49SMasahiro Yamada #define container_of(ptr, type, member) ({ \ 251cba1da49SMasahiro Yamada const typeof( ((type *)0)->member ) *__mptr = (ptr); \ 252cba1da49SMasahiro Yamada (type *)( (char *)__mptr - offsetof(type,member) );}) 253cba1da49SMasahiro Yamada 254cba1da49SMasahiro Yamada #endif 255