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-rw-r--r--arch/powerpc/platforms/powernv/opal-power.c174
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..2a3717fc2
--- /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 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;
+}