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Diffstat (limited to 'lib/cmdline.c')
-rw-r--r-- | lib/cmdline.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/lib/cmdline.c b/lib/cmdline.c new file mode 100644 index 00000000..f5f3ad8b --- /dev/null +++ b/lib/cmdline.c @@ -0,0 +1,159 @@ +/* + * 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> + +/* + * If a hyphen was found in get_option, this will handle the + * range of numbers, M-N. This will expand the range and insert + * the values[M, M+1, ..., N] into the ints array in get_options. + */ + +static int get_range(char **str, int *pint) +{ + int x, inc_counter, upper_range; + + (*str)++; + upper_range = simple_strtol((*str), NULL, 0); + inc_counter = upper_range - *pint; + for (x = *pint; x < upper_range; x++) + *pint++ = x; + return inc_counter; +} + +/** + * 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 + * 3 - hyphen found to denote a range + */ + +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; + } + if (**str == '-') + return 3; + + 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, a hyphen-separated range of _positive_ integers, + * or a combination of both. 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; + if (res == 3) { + int range_nums; + range_nums = get_range((char **)&str, ints + i); + if (range_nums < 0) + break; + /* + * Decrement the result by one to leave out the + * last number in the range. The next iteration + * will handle the upper number in the range + */ + i += (range_nums - 1); + } + 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) Optional 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(const char *ptr, char **retptr) +{ + char *endptr; /* local pointer to end of parsed string */ + + unsigned long long ret = simple_strtoull(ptr, &endptr, 0); + + switch (*endptr) { + case 'G': + case 'g': + ret <<= 10; + case 'M': + case 'm': + ret <<= 10; + case 'K': + case 'k': + ret <<= 10; + endptr++; + default: + break; + } + + if (retptr) + *retptr = endptr; + + return ret; +} + + +EXPORT_SYMBOL(memparse); +EXPORT_SYMBOL(get_option); +EXPORT_SYMBOL(get_options); |