1 files changed, 174 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 000000000..db99ffcb7
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-power.c
@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * PowerNV OPAL power control for graceful shutdown handling
+ *
+ * Copyright 2015 IBM Corp.
+ */
+
+#define pr_fmt(fmt)	"opal-power: "	fmt
+
+#include <linux/kernel.h>
+#include <linux/reboot.h>
+#include <linux/notifier.h>
+#include <linux/of.h>
+
+#include <asm/opal.h>
+#include <asm/machdep.h>
+
+#define SOFT_OFF 0x00
+#define SOFT_REBOOT 0x01
+
+/* Detect EPOW event */
+static bool detect_epow(void)
+{
+	u16 epow;
+	int i, rc;
+	__be16 epow_classes;
+	__be16 opal_epow_status[OPAL_SYSEPOW_MAX] = {0};
+
+	/*
+	* Check for EPOW event. Kernel sends supported EPOW classes info
+	* to OPAL. OPAL returns EPOW info along with classes present.
+	*/
+	epow_classes = cpu_to_be16(OPAL_SYSEPOW_MAX);
+	rc = opal_get_epow_status(opal_epow_status, &epow_classes);
+	if (rc != OPAL_SUCCESS) {
+		pr_err("Failed to get EPOW event information\n");
+		return false;
+	}
+
+	/* Look for EPOW events present */
+	for (i = 0; i < be16_to_cpu(epow_classes); i++) {
+		epow = be16_to_cpu(opal_epow_status[i]);
+
+		/* Filter events which do not need shutdown. */
+		if (i == OPAL_SYSEPOW_POWER)
+			epow &= ~(OPAL_SYSPOWER_CHNG | OPAL_SYSPOWER_FAIL |
+					OPAL_SYSPOWER_INCL);
+		if (epow)
+			return true;
+	}
+
+	return false;
+}
+
+/* Check for existing EPOW, DPO events */
+static bool __init poweroff_pending(void)
+{
+	int rc;
+	__be64 opal_dpo_timeout;
+
+	/* Check for DPO event */
+	rc = opal_get_dpo_status(&opal_dpo_timeout);
+	if (rc == OPAL_SUCCESS) {
+		pr_info("Existing DPO event detected.\n");
+		return true;
+	}
+
+	/* Check for EPOW event */
+	if (detect_epow()) {
+		pr_info("Existing EPOW event detected.\n");
+		return true;
+	}
+
+	return false;
+}
+
+/* OPAL power-control events notifier */
+static int opal_power_control_event(struct notifier_block *nb,
+					unsigned long msg_type, void *msg)
+{
+	uint64_t type;
+
+	switch (msg_type) {
+	case OPAL_MSG_EPOW:
+		if (detect_epow()) {
+			pr_info("EPOW msg received. Powering off system\n");
+			orderly_poweroff(true);
+		}
+		break;
+	case OPAL_MSG_DPO:
+		pr_info("DPO msg received. Powering off system\n");
+		orderly_poweroff(true);
+		break;
+	case OPAL_MSG_SHUTDOWN:
+		type = be64_to_cpu(((struct opal_msg *)msg)->params[0]);
+		switch (type) {
+		case SOFT_REBOOT:
+			pr_info("Reboot requested\n");
+			orderly_reboot();
+			break;
+		case SOFT_OFF:
+			pr_info("Poweroff requested\n");
+			orderly_poweroff(true);
+			break;
+		default:
+			pr_err("Unknown power-control type %llu\n", type);
+		}
+		break;
+	default:
+		pr_err("Unknown OPAL message type %lu\n", msg_type);
+	}
+
+	return 0;
+}
+
+/* OPAL EPOW event notifier block */
+static struct notifier_block opal_epow_nb = {
+	.notifier_call	= opal_power_control_event,
+	.next		= NULL,
+	.priority	= 0,
+};
+
+/* OPAL DPO event notifier block */
+static struct notifier_block opal_dpo_nb = {
+	.notifier_call	= opal_power_control_event,
+	.next		= NULL,
+	.priority	= 0,
+};
+
+/* OPAL power-control event notifier block */
+static struct notifier_block opal_power_control_nb = {
+	.notifier_call	= opal_power_control_event,
+	.next		= NULL,
+	.priority	= 0,
+};
+
+int __init opal_power_control_init(void)
+{
+	int ret, supported = 0;
+	struct device_node *np;
+
+	/* Register OPAL power-control events notifier */
+	ret = opal_message_notifier_register(OPAL_MSG_SHUTDOWN,
+						&opal_power_control_nb);
+	if (ret)
+		pr_err("Failed to register SHUTDOWN notifier, ret = %d\n", ret);
+
+	/* Determine OPAL EPOW, DPO support */
+	np = of_find_node_by_path("/ibm,opal/epow");
+	if (np) {
+		supported = of_device_is_compatible(np, "ibm,opal-v3-epow");
+		of_node_put(np);
+	}
+
+	if (!supported)
+		return 0;
+	pr_info("OPAL EPOW, DPO support detected.\n");
+
+	/* Register EPOW event notifier */
+	ret = opal_message_notifier_register(OPAL_MSG_EPOW, &opal_epow_nb);
+	if (ret)
+		pr_err("Failed to register EPOW notifier, ret = %d\n", ret);
+
+	/* Register DPO event notifier */
+	ret = opal_message_notifier_register(OPAL_MSG_DPO, &opal_dpo_nb);
+	if (ret)
+		pr_err("Failed to register DPO notifier, ret = %d\n", ret);
+
+	/* Check for any pending EPOW or DPO events. */
+	if (poweroff_pending())
+		orderly_poweroff(true);
+
+	return 0;
+}