cmdline.c

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/*
 * 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/export.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;
}

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;
}

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;
}

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);