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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Paul Gortmaker8bc3bcc2011-11-16 21:29:17 -050015#include <linux/export.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/kernel.h>
17#include <linux/string.h>
18
Derek Fults22f2e282006-12-06 20:37:11 -080019/*
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}
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
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:
Robert P. J. Day72fd4a32007-02-10 01:45:59 -080046 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 */
51
Felipe Contreras9fd43052014-01-23 15:54:35 -080052int get_option(char **str, int *pint)
Linus Torvalds1da177e2005-04-16 15:20:36 -070053{
54 char *cur = *str;
55
56 if (!cur || !(*cur))
57 return 0;
Felipe Contreras9fd43052014-01-23 15:54:35 -080058 *pint = simple_strtol(cur, str, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 if (cur == *str)
60 return 0;
61 if (**str == ',') {
62 (*str)++;
63 return 2;
64 }
Derek Fults22f2e282006-12-06 20:37:11 -080065 if (**str == '-')
66 return 3;
Linus Torvalds1da177e2005-04-16 15:20:36 -070067
68 return 1;
69}
Felipe Contrerasff6f9bb2014-01-23 15:54:36 -080070EXPORT_SYMBOL(get_option);
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
72/**
73 * get_options - Parse a string into a list of integers
74 * @str: String to be parsed
75 * @nints: size of integer array
76 * @ints: integer array
77 *
78 * This function parses a string containing a comma-separated
Derek Fults22f2e282006-12-06 20:37:11 -080079 * list of integers, a hyphen-separated range of _positive_ integers,
80 * or a combination of both. The parse halts when the array is
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 * full, or when no more numbers can be retrieved from the
82 * string.
83 *
84 * Return value is the character in the string which caused
85 * the parse to end (typically a null terminator, if @str is
86 * completely parseable).
87 */
Felipe Contreras9fd43052014-01-23 15:54:35 -080088
Linus Torvalds1da177e2005-04-16 15:20:36 -070089char *get_options(const char *str, int nints, int *ints)
90{
91 int res, i = 1;
92
93 while (i < nints) {
Felipe Contreras9fd43052014-01-23 15:54:35 -080094 res = get_option((char **)&str, ints + i);
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 if (res == 0)
96 break;
Derek Fults22f2e282006-12-06 20:37:11 -080097 if (res == 3) {
98 int range_nums;
99 range_nums = get_range((char **)&str, ints + i);
100 if (range_nums < 0)
101 break;
102 /*
103 * Decrement the result by one to leave out the
104 * last number in the range. The next iteration
105 * will handle the upper number in the range
106 */
107 i += (range_nums - 1);
108 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 i++;
110 if (res == 1)
111 break;
112 }
113 ints[0] = i - 1;
114 return (char *)str;
115}
Felipe Contrerasff6f9bb2014-01-23 15:54:36 -0800116EXPORT_SYMBOL(get_options);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117
118/**
119 * memparse - parse a string with mem suffixes into a number
120 * @ptr: Where parse begins
Robert P. J. Dayfd193822008-07-25 01:45:31 -0700121 * @retptr: (output) Optional pointer to next char after parse completes
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 *
123 * Parses a string into a number. The number stored at @ptr is
124 * potentially suffixed with %K (for kilobytes, or 1024 bytes),
125 * %M (for megabytes, or 1048576 bytes), or %G (for gigabytes, or
126 * 1073741824). If the number is suffixed with K, M, or G, then
127 * the return value is the number multiplied by one kilobyte, one
128 * megabyte, or one gigabyte, respectively.
129 */
130
Jeremy Fitzhardinged974ae32008-07-24 16:27:46 -0700131unsigned long long memparse(const char *ptr, char **retptr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132{
Robert P. J. Dayfd193822008-07-25 01:45:31 -0700133 char *endptr; /* local pointer to end of parsed string */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134
Robert P. J. Dayfd193822008-07-25 01:45:31 -0700135 unsigned long long ret = simple_strtoull(ptr, &endptr, 0);
136
137 switch (*endptr) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 case 'G':
139 case 'g':
140 ret <<= 10;
141 case 'M':
142 case 'm':
143 ret <<= 10;
144 case 'K':
145 case 'k':
146 ret <<= 10;
Robert P. J. Dayfd193822008-07-25 01:45:31 -0700147 endptr++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 default:
149 break;
150 }
Robert P. J. Dayfd193822008-07-25 01:45:31 -0700151
152 if (retptr)
153 *retptr = endptr;
154
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 return ret;
156}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157EXPORT_SYMBOL(memparse);