1 files changed, 61 insertions, 0 deletions

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index ebb0a2bcdc08..c5330f601b68 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -3,6 +3,7 @@
 #include <linux/init.h>
 #include <linux/bootmem.h>
 #include <linux/percpu.h>
+#include <linux/kexec.h>
 #include <asm/smp.h>
 #include <asm/percpu.h>
 #include <asm/sections.h>
@@ -11,6 +12,7 @@
 #include <asm/topology.h>
 #include <asm/mpspec.h>
 #include <asm/apicdef.h>
+#include <asm/highmem.h>
 
 #ifdef CONFIG_X86_LOCAL_APIC
 unsigned int num_processors;
@@ -404,3 +406,62 @@ EXPORT_SYMBOL(node_to_cpumask);
 #endif /* CONFIG_DEBUG_PER_CPU_MAPS */
 
 #endif /* X86_64_NUMA */
+
+
+/*
+ * --------- Crashkernel reservation ------------------------------
+ */
+
+static inline unsigned long long get_total_mem(void)
+{
+        unsigned long long total;
+
+        total = max_low_pfn - min_low_pfn;
+#ifdef CONFIG_HIGHMEM
+        total += highend_pfn - highstart_pfn;
+#endif
+
+        return total << PAGE_SHIFT;
+}
+
+#ifdef CONFIG_KEXEC
+void __init reserve_crashkernel(void)
+{
+        unsigned long long total_mem;
+        unsigned long long crash_size, crash_base;
+        int ret;
+
+        total_mem = get_total_mem();
+
+        ret = parse_crashkernel(boot_command_line, total_mem,
+                        &crash_size, &crash_base);
+        if (ret == 0 && crash_size > 0) {
+                if (crash_base <= 0) {
+                        printk(KERN_INFO "crashkernel reservation failed - "
+                                        "you have to specify a base address\n");
+                        return;
+                }
+
+                if (reserve_bootmem_generic(crash_base, crash_size,
+                                        BOOTMEM_EXCLUSIVE) < 0) {
+                        printk(KERN_INFO "crashkernel reservation failed - "
+                                        "memory is in use\n");
+                        return;
+                }
+
+                printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
+                                "for crashkernel (System RAM: %ldMB)\n",
+                                (unsigned long)(crash_size >> 20),
+                                (unsigned long)(crash_base >> 20),
+                                (unsigned long)(total_mem >> 20));
+
+                crashk_res.start = crash_base;
+                crashk_res.end   = crash_base + crash_size - 1;
+                insert_resource(&iomem_resource, &crashk_res);
+        }
+}
+#else
+void __init reserve_crashkernel(void)
+{}
+#endif
+