1 files changed, 99 insertions, 0 deletions
diff --git a/drivers/s390/char/sclp_quiesce.c b/drivers/s390/char/sclp_quiesce.c
new file mode 100644
index 00000000000..83f75774df6
--- /dev/null
+++ b/drivers/s390/char/sclp_quiesce.c
@@ -0,0 +1,99 @@
+/*
+ *  drivers/s390/char/sclp_quiesce.c
+ *     signal quiesce handler
+ *
+ *  (C) Copyright IBM Corp. 1999,2004
+ *  Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ *             Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/cpumask.h>
+#include <linux/smp.h>
+#include <linux/init.h>
+#include <asm/atomic.h>
+#include <asm/ptrace.h>
+#include <asm/sigp.h>
+
+#include "sclp.h"
+
+
+#ifdef CONFIG_SMP
+/* Signal completion of shutdown process. All CPUs except the first to enter
+ * this function: go to stopped state. First CPU: wait until all other
+ * CPUs are in stopped or check stop state. Afterwards, load special PSW
+ * to indicate completion. */
+static void
+do_load_quiesce_psw(void * __unused)
+{
+	static atomic_t cpuid = ATOMIC_INIT(-1);
+	psw_t quiesce_psw;
+	int cpu;
+
+	if (atomic_compare_and_swap(-1, smp_processor_id(), &cpuid))
+		signal_processor(smp_processor_id(), sigp_stop);
+	/* Wait for all other cpus to enter stopped state */
+	for_each_online_cpu(cpu) {
+		if (cpu == smp_processor_id())
+			continue;
+		while(!smp_cpu_not_running(cpu))
+			cpu_relax();
+	}
+	/* Quiesce the last cpu with the special psw */
+	quiesce_psw.mask = PSW_BASE_BITS | PSW_MASK_WAIT;
+	quiesce_psw.addr = 0xfff;
+	__load_psw(quiesce_psw);
+}
+
+/* Shutdown handler. Perform shutdown function on all CPUs. */
+static void
+do_machine_quiesce(void)
+{
+	on_each_cpu(do_load_quiesce_psw, NULL, 0, 0);
+}
+#else
+/* Shutdown handler. Signal completion of shutdown by loading special PSW. */
+static void
+do_machine_quiesce(void)
+{
+	psw_t quiesce_psw;
+
+	quiesce_psw.mask = PSW_BASE_BITS | PSW_MASK_WAIT;
+	quiesce_psw.addr = 0xfff;
+	__load_psw(quiesce_psw);
+}
+#endif
+
+extern void ctrl_alt_del(void);
+
+/* Handler for quiesce event. Start shutdown procedure. */
+static void
+sclp_quiesce_handler(struct evbuf_header *evbuf)
+{
+	_machine_restart = (void *) do_machine_quiesce;
+	_machine_halt = do_machine_quiesce;
+	_machine_power_off = do_machine_quiesce;
+	ctrl_alt_del();
+}
+
+static struct sclp_register sclp_quiesce_event = {
+	.receive_mask = EvTyp_SigQuiesce_Mask,
+	.receiver_fn = sclp_quiesce_handler
+};
+
+/* Initialize quiesce driver. */
+static int __init
+sclp_quiesce_init(void)
+{
+	int rc;
+
+	rc = sclp_register(&sclp_quiesce_event);
+	if (rc)
+		printk(KERN_WARNING "sclp: could not register quiesce handler "
+		       "(rc=%d)\n", rc);
+	return rc;
+}
+
+module_init(sclp_quiesce_init);