[S390] s390: hibernation support for s390

This patch introduces the hibernation backend support to the
s390 architecture. Now it is possible to suspend a mainframe Linux
guest using the following command:

echo disk > /sys/power/state

Signed-off-by: Hans-Joachim Picht <hans@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index cc8c484..fd8e311 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -1,7 +1,7 @@
 /*
  *  arch/s390/kernel/smp.c
  *
- *    Copyright IBM Corp. 1999,2007
+ *    Copyright IBM Corp. 1999, 2009
  *    Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
  *		 Martin Schwidefsky (schwidefsky@de.ibm.com)
  *		 Heiko Carstens (heiko.carstens@de.ibm.com)
@@ -1031,6 +1031,42 @@
 static SYSDEV_CLASS_ATTR(dispatching, 0644, dispatching_show,
 			 dispatching_store);
 
+/*
+ * If the resume kernel runs on another cpu than the suspended kernel,
+ * we have to switch the cpu IDs in the logical map.
+ */
+void smp_switch_boot_cpu_in_resume(u32 resume_phys_cpu_id,
+				   struct _lowcore *suspend_lowcore)
+{
+	int cpu, suspend_cpu_id, resume_cpu_id;
+	u32 suspend_phys_cpu_id;
+
+	suspend_phys_cpu_id = __cpu_logical_map[suspend_lowcore->cpu_nr];
+	suspend_cpu_id = suspend_lowcore->cpu_nr;
+
+	for_each_present_cpu(cpu) {
+		if (__cpu_logical_map[cpu] == resume_phys_cpu_id) {
+			resume_cpu_id = cpu;
+			goto found;
+		}
+	}
+	panic("Could not find resume cpu in logical map.\n");
+
+found:
+	printk("Resume  cpu ID: %i/%i\n", resume_phys_cpu_id, resume_cpu_id);
+	printk("Suspend cpu ID: %i/%i\n", suspend_phys_cpu_id, suspend_cpu_id);
+
+	__cpu_logical_map[resume_cpu_id] = suspend_phys_cpu_id;
+	__cpu_logical_map[suspend_cpu_id] = resume_phys_cpu_id;
+
+	lowcore_ptr[suspend_cpu_id]->cpu_addr = resume_phys_cpu_id;
+}
+
+u32 smp_get_phys_cpu_id(void)
+{
+	return __cpu_logical_map[smp_processor_id()];
+}
+
 static int __init topology_init(void)
 {
 	int cpu;