powerpc/powernv: Add OPAL soft-poweroff routine

Register a notifier for a OPAL message indicating that the machine
should prepare itself for a graceful power off.

OPAL will tell us if the power off is a reboot or shutdown, but for now
we perform the same orderly_poweroff action.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 65 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/powernv/opal-power.c b/arch/powerpc/platforms/powernv/opal-power.c
new file mode 100644
index 000000000000..48bf5b080bcf
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-power.c
@@ -0,0 +1,65 @@
+/*
+ * PowerNV OPAL power control for graceful shutdown handling
+ *
+ * Copyright 2015 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/reboot.h>
+#include <linux/notifier.h>
+
+#include <asm/opal.h>
+#include <asm/machdep.h>
+
+#define SOFT_OFF 0x00
+#define SOFT_REBOOT 0x01
+
+static int opal_power_control_event(struct notifier_block *nb,
+				    unsigned long msg_type, void *msg)
+{
+	struct opal_msg *power_msg = msg;
+	uint64_t type;
+
+	type = be64_to_cpu(power_msg->params[0]);
+
+	switch (type) {
+	case SOFT_REBOOT:
+		/* Fall through. The service processor is responsible for
+		 * bringing the machine back up */
+	case SOFT_OFF:
+		pr_info("OPAL: poweroff requested\n");
+		orderly_poweroff(true);
+		break;
+	default:
+		pr_err("OPAL: power control type unexpected %016llx\n", type);
+	}
+
+	return 0;
+}
+
+static struct notifier_block opal_power_control_nb = {
+	.notifier_call	= opal_power_control_event,
+	.next		= NULL,
+	.priority	= 0,
+};
+
+static int __init opal_power_control_init(void)
+{
+	int ret;
+
+	ret = opal_message_notifier_register(OPAL_MSG_SHUTDOWN,
+					     &opal_power_control_nb);
+	if (ret) {
+		pr_err("%s: Can't register OPAL event notifier (%d)\n",
+				__func__, ret);
+		return ret;
+	}
+
+	return 0;
+}
+machine_subsys_initcall(powernv, opal_power_control_init);