+#ifdef CONFIG_KEXEC
+#include <linux/kexec.h>
+
+static ssize_t show_crash_notes(struct sys_device *dev, char *buf)
+{
+ struct cpu *cpu = container_of(dev, struct cpu, sysdev);
+ ssize_t rc;
+ unsigned long long addr;
+ int cpunum;
+
+ cpunum = cpu->sysdev.id;
+
+ /*
+ * Might be reading other cpu's data based on which cpu read thread
+ * has been scheduled. But cpu data (memory) is allocated once during
+ * boot up and this data does not change there after. Hence this
+ * operation should be safe. No locking required.
+ */
+ addr = __pa(per_cpu_ptr(crash_notes, cpunum));
+ rc = sprintf(buf, "%Lx\n", addr);
+ return rc;
+}
+static SYSDEV_ATTR(crash_notes, 0400, show_crash_notes, NULL);
+#endif
+