1/*
2 * linux/lib/cmdline.c
3 * Helper functions generally used for parsing kernel command line
4 * and module options.
5 *
6 * Code and copyrights come from init/main.c and arch/i386/kernel/setup.c.
7 *
8 * This source code is licensed under the GNU General Public License,
9 * Version 2.  See the file COPYING for more details.
10 *
11 * GNU Indent formatting options for this file: -kr -i8 -npsl -pcs
12 *
13 */
14
15#include <linux/module.h>
16#include <linux/kernel.h>
17#include <linux/string.h>
18
19/*
20 *	If a hyphen was found in get_option, this will handle the
21 *	range of numbers, M-N.  This will expand the range and insert
22 *	the values[M, M+1, ..., N] into the ints array in get_options.
23 */
24
25static int get_range(char **str, int *pint)
26{
27	int x, inc_counter, upper_range;
28
29	(*str)++;
30	upper_range = simple_strtol((*str), NULL, 0);
31	inc_counter = upper_range - *pint;
32	for (x = *pint; x < upper_range; x++)
33		*pint++ = x;
34	return inc_counter;
35}
36
37/**
38 *	get_option - Parse integer from an option string
39 *	@str: option string
40 *	@pint: (output) integer value parsed from @str
41 *
42 *	Read an int from an option string; if available accept a subsequent
43 *	comma as well.
44 *
45 *	Return values:
46 *	0 - no int in string
47 *	1 - int found, no subsequent comma
48 *	2 - int found including a subsequent comma
49 *	3 - hyphen found to denote a range
50 */
51
52int get_option (char **str, int *pint)
53{
54	char *cur = *str;
55
56	if (!cur || !(*cur))
57		return 0;
58	*pint = simple_strtol (cur, str, 0);
59	if (cur == *str)
60		return 0;
61	if (**str == ',') {
62		(*str)++;
63		return 2;
64	}
65	if (**str == '-')
66		return 3;
67
68	return 1;
69}
70
71/**
72 *	get_options - Parse a string into a list of integers
73 *	@str: String to be parsed
74 *	@nints: size of integer array
75 *	@ints: integer array
76 *
77 *	This function parses a string containing a comma-separated
78 *	list of integers, a hyphen-separated range of _positive_ integers,
79 *	or a combination of both.  The parse halts when the array is
80 *	full, or when no more numbers can be retrieved from the
81 *	string.
82 *
83 *	Return value is the character in the string which caused
84 *	the parse to end (typically a null terminator, if @str is
85 *	completely parseable).
86 */
87
88char *get_options(const char *str, int nints, int *ints)
89{
90	int res, i = 1;
91
92	while (i < nints) {
93		res = get_option ((char **)&str, ints + i);
94		if (res == 0)
95			break;
96		if (res == 3) {
97			int range_nums;
98			range_nums = get_range((char **)&str, ints + i);
99			if (range_nums < 0)
100				break;
101			/*
102			 * Decrement the result by one to leave out the
103			 * last number in the range.  The next iteration
104			 * will handle the upper number in the range
105			 */
106			i += (range_nums - 1);
107		}
108		i++;
109		if (res == 1)
110			break;
111	}
112	ints[0] = i - 1;
113	return (char *)str;
114}
115
116/**
117 *	memparse - parse a string with mem suffixes into a number
118 *	@ptr: Where parse begins
119 *	@retptr: (output) Pointer to next char after parse completes
120 *
121 *	Parses a string into a number.  The number stored at @ptr is
122 *	potentially suffixed with %K (for kilobytes, or 1024 bytes),
123 *	%M (for megabytes, or 1048576 bytes), or %G (for gigabytes, or
124 *	1073741824).  If the number is suffixed with K, M, or G, then
125 *	the return value is the number multiplied by one kilobyte, one
126 *	megabyte, or one gigabyte, respectively.
127 */
128
129unsigned long long memparse (char *ptr, char **retptr)
130{
131	unsigned long long ret = simple_strtoull (ptr, retptr, 0);
132
133	switch (**retptr) {
134	case 'G':
135	case 'g':
136		ret <<= 10;
137	case 'M':
138	case 'm':
139		ret <<= 10;
140	case 'K':
141	case 'k':
142		ret <<= 10;
143		(*retptr)++;
144	default:
145		break;
146	}
147	return ret;
148}
149
150
151EXPORT_SYMBOL(memparse);
152EXPORT_SYMBOL(get_option);
153EXPORT_SYMBOL(get_options);
154