| /* |
| * 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. |
| */ |
| |
| #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, |
| }; |
| |
| static 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; |
| } |
| machine_subsys_initcall(powernv, opal_power_control_init); |