diff options
| -rw-r--r-- | include/linux/kernel.h | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 527ed40..f84a764 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -4,16 +4,41 @@ #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])) @@ -27,10 +52,24 @@ #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 + #define roundup(x, 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 @@ -127,6 +166,27 @@ _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 + * @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. @@ -144,6 +204,38 @@ __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. |