2 files changed, 33 insertions, 0 deletions

diff --git a/arch/x86_64/kernel/e820.c b/arch/x86_64/kernel/e820.c
index cf4878309b04..6ded3a50dfe6 100644
--- a/arch/x86_64/kernel/e820.c
+++ b/arch/x86_64/kernel/e820.c
@@ -16,6 +16,7 @@
 #include <linux/bootmem.h>
 #include <linux/ioport.h>
 #include <linux/string.h>
+#include <linux/kexec.h>
 #include <asm/page.h>
 #include <asm/e820.h>
 #include <asm/proto.h>
@@ -210,6 +211,9 @@ void __init e820_reserve_resources(void)
                          */
                         request_resource(res, &code_resource);
                         request_resource(res, &data_resource);
+#ifdef CONFIG_KEXEC
+                        request_resource(res, &crashk_res);
+#endif
                 }
         }
 }
diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c
index ca9a915a6d4a..b02d921da4f7 100644
--- a/arch/x86_64/kernel/setup.c
+++ b/arch/x86_64/kernel/setup.c
@@ -41,6 +41,7 @@
 #include <linux/kallsyms.h>
 #include <linux/edd.h>
 #include <linux/mmzone.h>
+#include <linux/kexec.h>
 
 #include <asm/mtrr.h>
 #include <asm/uaccess.h>
@@ -367,6 +368,27 @@ static __init void parse_cmdline_early (char ** cmdline_p)
                 if (!memcmp(from, "noexec=", 7))
                         nonx_setup(from + 7);
 
+#ifdef CONFIG_KEXEC
+                /* crashkernel=size@addr specifies the location to reserve for
+                 * a crash kernel.  By reserving this memory we guarantee
+                 * that linux never set's it up as a DMA target.
+                 * Useful for holding code to do something appropriate
+                 * after a kernel panic.
+                 */
+                else if (!memcmp(from, "crashkernel=", 12)) {
+                        unsigned long size, base;
+                        size = memparse(from+12, &from);
+                        if (*from == '@') {
+                                base = memparse(from+1, &from);
+                                /* FIXME: Do I want a sanity check
+                                 * to validate the memory range?
+                                 */
+                                crashk_res.start = base;
+                                crashk_res.end   = base + size - 1;
+                        }
+                }
+#endif
+
         next_char:
                 c = *(from++);
                 if (!c)
@@ -625,6 +647,13 @@ void __init setup_arch(char **cmdline_p)
 #endif
 
         sparse_init();
+
+#ifdef CONFIG_KEXEC
+        if (crashk_res.start != crashk_res.end) {
+                reserve_bootmem(crashk_res.start,
+                        crashk_res.end - crashk_res.start + 1);
+        }
+#endif
         paging_init();
 
         check_ioapic();