acrn-kernel/lib/cmdline.c

121 lines
2.7 KiB
C

/*
* linux/lib/cmdline.c
* Helper functions generally used for parsing kernel command line
* and module options.
*
* Code and copyrights come from init/main.c and arch/i386/kernel/setup.c.
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*
* GNU Indent formatting options for this file: -kr -i8 -npsl -pcs
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
/**
* get_option - Parse integer from an option string
* @str: option string
* @pint: (output) integer value parsed from @str
*
* Read an int from an option string; if available accept a subsequent
* comma as well.
*
* Return values:
* 0 : no int in string
* 1 : int found, no subsequent comma
* 2 : int found including a subsequent comma
*/
int get_option (char **str, int *pint)
{
char *cur = *str;
if (!cur || !(*cur))
return 0;
*pint = simple_strtol (cur, str, 0);
if (cur == *str)
return 0;
if (**str == ',') {
(*str)++;
return 2;
}
return 1;
}
/**
* get_options - Parse a string into a list of integers
* @str: String to be parsed
* @nints: size of integer array
* @ints: integer array
*
* This function parses a string containing a comma-separated
* list of integers. The parse halts when the array is
* full, or when no more numbers can be retrieved from the
* string.
*
* Return value is the character in the string which caused
* the parse to end (typically a null terminator, if @str is
* completely parseable).
*/
char *get_options(const char *str, int nints, int *ints)
{
int res, i = 1;
while (i < nints) {
res = get_option ((char **)&str, ints + i);
if (res == 0)
break;
i++;
if (res == 1)
break;
}
ints[0] = i - 1;
return (char *)str;
}
/**
* memparse - parse a string with mem suffixes into a number
* @ptr: Where parse begins
* @retptr: (output) Pointer to next char after parse completes
*
* Parses a string into a number. The number stored at @ptr is
* potentially suffixed with %K (for kilobytes, or 1024 bytes),
* %M (for megabytes, or 1048576 bytes), or %G (for gigabytes, or
* 1073741824). If the number is suffixed with K, M, or G, then
* the return value is the number multiplied by one kilobyte, one
* megabyte, or one gigabyte, respectively.
*/
unsigned long long memparse (char *ptr, char **retptr)
{
unsigned long long ret = simple_strtoull (ptr, retptr, 0);
switch (**retptr) {
case 'G':
case 'g':
ret <<= 10;
case 'M':
case 'm':
ret <<= 10;
case 'K':
case 'k':
ret <<= 10;
(*retptr)++;
default:
break;
}
return ret;
}
EXPORT_SYMBOL(memparse);
EXPORT_SYMBOL(get_option);
EXPORT_SYMBOL(get_options);