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 25 static 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 52 int 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 88 char *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) Optional 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 */ 128 129 unsigned long long memparse(const char *ptr, char **retptr) 130 { 131 char *endptr; /* local pointer to end of parsed string */ 132 133 unsigned long long ret = simple_strtoull(ptr, &endptr, 0); 134 135 switch (*endptr) { 136 case 'G': 137 case 'g': 138 ret <<= 10; 139 case 'M': 140 case 'm': 141 ret <<= 10; 142 case 'K': 143 case 'k': 144 ret <<= 10; 145 endptr++; 146 default: 147 break; 148 } 149 150 if (retptr) 151 *retptr = endptr; 152 153 return ret; 154 } 155 156 157 EXPORT_SYMBOL(memparse); 158 EXPORT_SYMBOL(get_option); 159 EXPORT_SYMBOL(get_options); 160