2 files changed, 168 insertions, 0 deletions

diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index ad4b82ce84af..2d9c448d8c52 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -187,6 +187,8 @@ extern u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
 extern size_t vmcoreinfo_size;
 extern size_t vmcoreinfo_max_size;
 
+int __init parse_crashkernel(char *cmdline, unsigned long long system_ram,
+                unsigned long long *crash_size, unsigned long long *crash_base);
 
 #else /* !CONFIG_KEXEC */
 struct pt_regs;
diff --git a/kernel/kexec.c b/kernel/kexec.c
index fbffdb457cce..aa74a1ef2da8 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1146,6 +1146,172 @@ static int __init crash_notes_memory_init(void)
 }
 module_init(crash_notes_memory_init)
 
+
+/*
+ * parsing the "crashkernel" commandline
+ *
+ * this code is intended to be called from architecture specific code
+ */
+
+
+/*
+ * This function parses command lines in the format
+ *
+ *   crashkernel=ramsize-range:size[,...][@offset]
+ *
+ * The function returns 0 on success and -EINVAL on failure.
+ */
+static int __init parse_crashkernel_mem(char                    *cmdline,
+                                        unsigned long long      system_ram,
+                                        unsigned long long      *crash_size,
+                                        unsigned long long      *crash_base)
+{
+        char *cur = cmdline, *tmp;
+
+        /* for each entry of the comma-separated list */
+        do {
+                unsigned long long start, end = ULLONG_MAX, size;
+
+                /* get the start of the range */
+                start = memparse(cur, &tmp);
+                if (cur == tmp) {
+                        pr_warning("crashkernel: Memory value expected\n");
+                        return -EINVAL;
+                }
+                cur = tmp;
+                if (*cur != '-') {
+                        pr_warning("crashkernel: '-' expected\n");
+                        return -EINVAL;
+                }
+                cur++;
+
+                /* if no ':' is here, than we read the end */
+                if (*cur != ':') {
+                        end = memparse(cur, &tmp);
+                        if (cur == tmp) {
+                                pr_warning("crashkernel: Memory "
+                                                "value expected\n");
+                                return -EINVAL;
+                        }
+                        cur = tmp;
+                        if (end <= start) {
+                                pr_warning("crashkernel: end <= start\n");
+                                return -EINVAL;
+                        }
+                }
+
+                if (*cur != ':') {
+                        pr_warning("crashkernel: ':' expected\n");
+                        return -EINVAL;
+                }
+                cur++;
+
+                size = memparse(cur, &tmp);
+                if (cur == tmp) {
+                        pr_warning("Memory value expected\n");
+                        return -EINVAL;
+                }
+                cur = tmp;
+                if (size >= system_ram) {
+                        pr_warning("crashkernel: invalid size\n");
+                        return -EINVAL;
+                }
+
+                /* match ? */
+                if (system_ram >= start && system_ram <= end) {
+                        *crash_size = size;
+                        break;
+                }
+        } while (*cur++ == ',');
+
+        if (*crash_size > 0) {
+                while (*cur != ' ' && *cur != '@')
+                        cur++;
+                if (*cur == '@') {
+                        cur++;
+                        *crash_base = memparse(cur, &tmp);
+                        if (cur == tmp) {
+                                pr_warning("Memory value expected "
+                                                "after '@'\n");
+                                return -EINVAL;
+                        }
+                }
+        }
+
+        return 0;
+}
+
+/*
+ * That function parses "simple" (old) crashkernel command lines like
+ *
+ *      crashkernel=size[@offset]
+ *
+ * It returns 0 on success and -EINVAL on failure.
+ */
+static int __init parse_crashkernel_simple(char                 *cmdline,
+                                           unsigned long long   *crash_size,
+                                           unsigned long long   *crash_base)
+{
+        char *cur = cmdline;
+
+        *crash_size = memparse(cmdline, &cur);
+        if (cmdline == cur) {
+                pr_warning("crashkernel: memory value expected\n");
+                return -EINVAL;
+        }
+
+        if (*cur == '@')
+                *crash_base = memparse(cur+1, &cur);
+
+        return 0;
+}
+
+/*
+ * That function is the entry point for command line parsing and should be
+ * called from the arch-specific code.
+ */
+int __init parse_crashkernel(char                *cmdline,
+                             unsigned long long system_ram,
+                             unsigned long long *crash_size,
+                             unsigned long long *crash_base)
+{
+        char    *p = cmdline, *ck_cmdline = NULL;
+        char    *first_colon, *first_space;
+
+        BUG_ON(!crash_size || !crash_base);
+        *crash_size = 0;
+        *crash_base = 0;
+
+        /* find crashkernel and use the last one if there are more */
+        p = strstr(p, "crashkernel=");
+        while (p) {
+                ck_cmdline = p;
+                p = strstr(p+1, "crashkernel=");
+        }
+
+        if (!ck_cmdline)
+                return -EINVAL;
+
+        ck_cmdline += 12; /* strlen("crashkernel=") */
+
+        /*
+         * if the commandline contains a ':', then that's the extended
+         * syntax -- if not, it must be the classic syntax
+         */
+        first_colon = strchr(ck_cmdline, ':');
+        first_space = strchr(ck_cmdline, ' ');
+        if (first_colon && (!first_space || first_colon < first_space))
+                return parse_crashkernel_mem(ck_cmdline, system_ram,
+                                crash_size, crash_base);
+        else
+                return parse_crashkernel_simple(ck_cmdline, crash_size,
+                                crash_base);
+
+        return 0;
+}
+
+
+
 void crash_save_vmcoreinfo(void)
 {
         u32 *buf;