diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/minmax.h | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/include/linux/minmax.h b/include/linux/minmax.h index 396df1121bff..4f011eb6533d 100644 --- a/include/linux/minmax.h +++ b/include/linux/minmax.h @@ -3,6 +3,7 @@ #define _LINUX_MINMAX_H #include <linux/const.h> +#include <linux/types.h> /* * min()/max()/clamp() macros must accomplish three things: @@ -158,6 +159,32 @@ */ #define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi) +static inline bool in_range64(u64 val, u64 start, u64 len) +{ + return (val - start) < len; +} + +static inline bool in_range32(u32 val, u32 start, u32 len) +{ + return (val - start) < len; +} + +/** + * in_range - Determine if a value lies within a range. + * @val: Value to test. + * @start: First value in range. + * @len: Number of values in range. + * + * This is more efficient than "if (start <= val && val < (start + len))". + * It also gives a different answer if @start + @len overflows the size of + * the type by a sufficient amount to encompass @val. Decide for yourself + * which behaviour you want, or prove that start + len never overflow. + * Do not blindly replace one form with the other. + */ +#define in_range(val, start, len) \ + ((sizeof(start) | sizeof(len) | sizeof(val)) <= sizeof(u32) ? \ + in_range32(val, start, len) : in_range64(val, start, len)) + /** * swap - swap values of @a and @b * @a: first value |