diff options
Diffstat (limited to 'include/linux/kernel.h')
| -rw-r--r-- | include/linux/kernel.h | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h new file mode 100644 index 0000000..89fcae0 --- /dev/null +++ b/include/linux/kernel.h @@ -0,0 +1,245 @@ +#ifndef _LINUX_KERNEL_H +#define _LINUX_KERNEL_H + + +#include <linux/types.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 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 |