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/export.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 EXPORT_SYMBOL(get_option); 71 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 79 * list of integers, a hyphen-separated range of _positive_ integers, 80 * or a combination of both. The parse halts when the array is 81 * 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 */ 88 89 char *get_options(const char *str, int nints, int *ints) 90 { 91 int res, i = 1; 92 93 while (i < nints) { 94 res = get_option((char **)&str, ints + i); 95 if (res == 0) 96 break; 97 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 } 109 i++; 110 if (res == 1) 111 break; 112 } 113 ints[0] = i - 1; 114 return (char *)str; 115 } 116 EXPORT_SYMBOL(get_options); 117 118 /** 119 * memparse - parse a string with mem suffixes into a number 120 * @ptr: Where parse begins 121 * @retptr: (output) Optional pointer to next char after parse completes 122 * 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 */ 130 131 unsigned long long memparse(const char *ptr, char **retptr) 132 { 133 char *endptr; /* local pointer to end of parsed string */ 134 135 unsigned long long ret = simple_strtoull(ptr, &endptr, 0); 136 137 switch (*endptr) { 138 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; 147 endptr++; 148 default: 149 break; 150 } 151 152 if (retptr) 153 *retptr = endptr; 154 155 return ret; 156 } 157 EXPORT_SYMBOL(memparse); 158