From: Zhaoxiu Zeng <zhaoxiu.z...@gmail.com> Signed-off-by: Zhaoxiu Zeng <zhaoxiu.z...@gmail.com> --- include/linux/kernel.h | 15 ++++++++++++++- lib/hexdump.c | 36 +++++++++++++++++++----------------- 2 files changed, 33 insertions(+), 18 deletions(-)
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 94aa10f..72a0432 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -532,7 +532,20 @@ static inline char *hex_byte_pack_upper(char *buf, u8 byte) return buf; } -extern int hex_to_bin(char ch); +extern const int8_t h2b_lut[]; + +/** + * hex_to_bin - convert a hex digit to its real value + * @ch: ascii character represents hex digit + * + * hex_to_bin() converts one hex digit to its actual value or -1 in case of bad + * input. + */ +static inline int hex_to_bin(char ch) +{ + return h2b_lut[(unsigned char)ch]; +} + extern int __must_check hex2bin(u8 *dst, const char *src, size_t count); extern char *bin2hex(char *dst, const void *src, size_t count); diff --git a/lib/hexdump.c b/lib/hexdump.c index 992457b..878697f 100644 --- a/lib/hexdump.c +++ b/lib/hexdump.c @@ -18,23 +18,25 @@ EXPORT_SYMBOL(hex_asc); const char hex_asc_upper[] = "0123456789ABCDEF"; EXPORT_SYMBOL(hex_asc_upper); -/** - * hex_to_bin - convert a hex digit to its real value - * @ch: ascii character represents hex digit - * - * hex_to_bin() converts one hex digit to its actual value or -1 in case of bad - * input. - */ -int hex_to_bin(char ch) -{ - if ((ch >= '0') && (ch <= '9')) - return ch - '0'; - ch = tolower(ch); - if ((ch >= 'a') && (ch <= 'f')) - return ch - 'a' + 10; - return -1; -} -EXPORT_SYMBOL(hex_to_bin); +const int8_t h2b_lut[] = { + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, + -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, +}; +EXPORT_SYMBOL(h2b_lut); /** * hex2bin - convert an ascii hexadecimal string to its binary representation -- 2.7.4