On Wed, Dec 12, 2018 at 03:46:15PM +0800, Baoquan He wrote:
>On 12/12/18 at 11:10am, Chao Fan wrote:
>> Introduce kstrtoull() from lib/kstrtox.c to boot directory so that code
>
>It's not introducing kstrtoull(), just copying kstrtoull() from
>lib/kstrtox.c to boot.
Oops, maybe I misunderstand 'introduce'.
Thanks,
Chao Fan
>
>> in boot/ can use kstrtoull() and the old simple_strtoull() can be
>> replaced.
>>
>> Signed-off-by: Chao Fan <fanc.f...@cn.fujitsu.com>
>> ---
>> arch/x86/boot/string.c | 137 +++++++++++++++++++++++++++++++++++++++++
>> arch/x86/boot/string.h | 2 +
>> 2 files changed, 139 insertions(+)
>>
>> diff --git a/arch/x86/boot/string.c b/arch/x86/boot/string.c
>> index c4428a176973..e02405f20f98 100644
>> --- a/arch/x86/boot/string.c
>> +++ b/arch/x86/boot/string.c
>> @@ -12,7 +12,10 @@
>> * Very basic string functions
>> */
>>
>> +#define _LINUX_CTYPE_H
>> #include <linux/types.h>
>> +#include <linux/kernel.h>
>> +#include <linux/errno.h>
>> #include <asm/asm.h>
>> #include "ctype.h"
>> #include "string.h"
>> @@ -187,3 +190,137 @@ char *strchr(const char *s, int c)
>> return NULL;
>> return (char *)s;
>> }
>> +
>> +static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
>> +{
>> + union {
>> + u64 v64;
>> + u32 v32[2];
>> + } d = { dividend };
>> + u32 upper;
>> +
>> + upper = d.v32[1];
>> + d.v32[1] = 0;
>> + if (upper >= divisor) {
>> + d.v32[1] = upper / divisor;
>> + upper %= divisor;
>> + }
>> + asm ("divl %2" : "=a" (d.v32[0]), "=d" (*remainder) :
>> + "rm" (divisor), "0" (d.v32[0]), "1" (upper));
>> + return d.v64;
>> +}
>> +
>> +static inline u64 div_u64(u64 dividend, u32 divisor)
>> +{
>> + u32 remainder;
>> + return div_u64_rem(dividend, divisor, &remainder);
>> +}
>> +
>> +static inline char _tolower(const char c)
>> +{
>> + return c | 0x20;
>> +}
>> +
>> +const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)
>> +{
>> + if (*base == 0) {
>> + if (s[0] == '0') {
>> + if (_tolower(s[1]) == 'x' && isxdigit(s[2]))
>> + *base = 16;
>> + else
>> + *base = 8;
>> + } else
>> + *base = 10;
>> + }
>> + if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x')
>> + s += 2;
>> + return s;
>> +}
>> +
>> +/*
>> + * Convert non-negative integer string representation in explicitly given
>> radix
>> + * to an integer.
>> + * Return number of characters consumed maybe or-ed with overflow bit.
>> + * If overflow occurs, result integer (incorrect) is still returned.
>> + *
>> + * Don't you dare use this function.
>> + */
>> +unsigned int _parse_integer(const char *s, unsigned int base, unsigned long
>> long *p)
>> +{
>> + unsigned long long res;
>> + unsigned int rv;
>> +
>> + res = 0;
>> + rv = 0;
>> + while (1) {
>> + unsigned int c = *s;
>> + unsigned int lc = c | 0x20; /* don't tolower() this line */
>> + unsigned int val;
>> +
>> + if ('0' <= c && c <= '9')
>> + val = c - '0';
>> + else if ('a' <= lc && lc <= 'f')
>> + val = lc - 'a' + 10;
>> + else
>> + break;
>> +
>> + if (val >= base)
>> + break;
>> + /*
>> + * Check for overflow only if we are within range of
>> + * it in the max base we support (16)
>> + */
>> + if (unlikely(res & (~0ull << 60))) {
>> + if (res > div_u64(ULLONG_MAX - val, base))
>> + rv |= KSTRTOX_OVERFLOW;
>> + }
>> + res = res * base + val;
>> + rv++;
>> + s++;
>> + }
>> + *p = res;
>> + return rv;
>> +}
>> +
>> +static int _kstrtoull(const char *s, unsigned int base, unsigned long long
>> *res)
>> +{
>> + unsigned long long _res;
>> + unsigned int rv;
>> +
>> + s = _parse_integer_fixup_radix(s, &base);
>> + rv = _parse_integer(s, base, &_res);
>> + if (rv & KSTRTOX_OVERFLOW)
>> + return -ERANGE;
>> + if (rv == 0)
>> + return -EINVAL;
>> + s += rv;
>> + if (*s == '\n')
>> + s++;
>> + if (*s)
>> + return -EINVAL;
>> + *res = _res;
>> + return 0;
>> +}
>> +
>> +/**
>> + * kstrtoull - convert a string to an unsigned long long
>> + * @s: The start of the string. The string must be null-terminated, and may
>> also
>> + * include a single newline before its terminating null. The first
>> character
>> + * may also be a plus sign, but not a minus sign.
>> + * @base: The number base to use. The maximum supported base is 16. If base
>> is
>> + * given as 0, then the base of the string is automatically detected with
>> the
>> + * conventional semantics - If it begins with 0x the number will be parsed
>> as a
>> + * hexadecimal (case insensitive), if it otherwise begins with 0, it will
>> be
>> + * parsed as an octal number. Otherwise it will be parsed as a decimal.
>> + * @res: Where to write the result of the conversion on success.
>> + *
>> + * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
>> + * Used as a replacement for the obsolete simple_strtoull. Return code must
>> + * be checked.
>> + */
>> +int kstrtoull(const char *s, unsigned int base, unsigned long long *res)
>> +{
>> + if (s[0] == '+')
>> + s++;
>> + return _kstrtoull(s, base, res);
>> +}
>> diff --git a/arch/x86/boot/string.h b/arch/x86/boot/string.h
>> index 3d78e27077f4..171007c99acc 100644
>> --- a/arch/x86/boot/string.h
>> +++ b/arch/x86/boot/string.h
>> @@ -29,4 +29,6 @@ extern unsigned int atou(const char *s);
>> extern unsigned long long simple_strtoull(const char *cp, char **endp,
>> unsigned int base);
>>
>> +int kstrtoull(const char *s, unsigned int base, unsigned long long *res);
>> +#define KSTRTOX_OVERFLOW (1U << 31)
>> #endif /* BOOT_STRING_H */
>> --
>> 2.19.2
>>
>>
>>
>
>
