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-rw-r--r--lib/cmdline.c191
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diff --git a/lib/cmdline.c b/lib/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;
+}
+
+/**
+ * get_option - Parse integer from an option string
+ * @str: option string
+ * @pint: (output) integer value parsed from @str
+ *
+ * Read an int from an option string; if available accept a subsequent
+ * comma as well.
+ *
+ * Return values:
+ * 0 - no int in string
+ * 1 - int found, no subsequent comma
+ * 2 - int found including a subsequent comma
+ * 3 - hyphen found to denote a range
+ */
+
+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;
+}
+EXPORT_SYMBOL(get_option);
+
+/**
+ * get_options - Parse a string into a list of integers
+ * @str: String to be parsed
+ * @nints: size of integer array
+ * @ints: integer array
+ *
+ * This function parses a string containing a comma-separated
+ * list of integers, a hyphen-separated range of _positive_ integers,
+ * or a combination of both. The parse halts when the array is
+ * full, or when no more numbers can be retrieved from the
+ * string.
+ *
+ * Return value is the character in the string which caused
+ * the parse to end (typically a null terminator, if @str is
+ * completely parseable).
+ */
+
+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;
+}
+EXPORT_SYMBOL(get_options);
+
+/**
+ * memparse - parse a string with mem suffixes into a number
+ * @ptr: Where parse begins
+ * @retptr: (output) Optional pointer to next char after parse completes
+ *
+ * Parses a string into a number. The number stored at @ptr is
+ * potentially suffixed with K, M, G, T, P, E.
+ */
+
+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 'E':
+ case 'e':
+ ret <<= 10;
+ case 'P':
+ case 'p':
+ ret <<= 10;
+ case 'T':
+ case 't':
+ ret <<= 10;
+ 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);
+
+/**
+ * parse_option_str - Parse a string and check an option is set or not
+ * @str: String to be parsed
+ * @option: option name
+ *
+ * This function parses a string containing a comma-separated list of
+ * strings like a=b,c.
+ *
+ * Return true if there's such option in the string, or return false.
+ */
+bool parse_option_str(const char *str, const char *option)
+{
+ while (*str) {
+ if (!strncmp(str, option, strlen(option))) {
+ str += strlen(option);
+ if (!*str || *str == ',')
+ return true;
+ }
+
+ while (*str && *str != ',')
+ str++;
+
+ if (*str == ',')
+ str++;
+ }
+
+ return false;
+}