arch/powerpc/platforms/powernv/opal-power.c

   1 /*
   2  * PowerNV OPAL power control for graceful shutdown handling
   3  *
   4  * Copyright 2015 IBM Corp.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #define pr_fmt(fmt)     "opal-power: "  fmt
  13
  14 #include <linux/kernel.h>
  15 #include <linux/reboot.h>
  16 #include <linux/notifier.h>
  17 #include <linux/of.h>
  18
  19 #include <asm/opal.h>
  20 #include <asm/machdep.h>
  21
  22 #define SOFT_OFF 0x00
  23 #define SOFT_REBOOT 0x01
  24
  25 /* Detect EPOW event */
  26 static bool detect_epow(void)
  27 {
  28         u16 epow;
  29         int i, rc;
  30         __be16 epow_classes;
  31         __be16 opal_epow_status[OPAL_SYSEPOW_MAX] = {0};
  32
  33         /*
  34         * Check for EPOW event. Kernel sends supported EPOW classes info
  35         * to OPAL. OPAL returns EPOW info along with classes present.
  36         */
  37         epow_classes = cpu_to_be16(OPAL_SYSEPOW_MAX);
  38         rc = opal_get_epow_status(opal_epow_status, &epow_classes);
  39         if (rc != OPAL_SUCCESS) {
  40                 pr_err("Failed to get EPOW event information\n");
  41                 return false;
  42         }
  43
  44         /* Look for EPOW events present */
  45         for (i = 0; i < be16_to_cpu(epow_classes); i++) {
  46                 epow = be16_to_cpu(opal_epow_status[i]);
  47
  48                 /* Filter events which do not need shutdown. */
  49                 if (i == OPAL_SYSEPOW_POWER)
  50                         epow &= ~(OPAL_SYSPOWER_CHNG | OPAL_SYSPOWER_FAIL |
  51                                         OPAL_SYSPOWER_INCL);
  52                 if (epow)
  53                         return true;
  54         }
  55
  56         return false;
  57 }
  58
  59 /* Check for existing EPOW, DPO events */
  60 static bool poweroff_pending(void)
  61 {
  62         int rc;
  63         __be64 opal_dpo_timeout;
  64
  65         /* Check for DPO event */
  66         rc = opal_get_dpo_status(&opal_dpo_timeout);
  67         if (rc == OPAL_SUCCESS) {
  68                 pr_info("Existing DPO event detected.\n");
  69                 return true;
  70         }
  71
  72         /* Check for EPOW event */
  73         if (detect_epow()) {
  74                 pr_info("Existing EPOW event detected.\n");
  75                 return true;
  76         }
  77
  78         return false;
  79 }
  80
  81 /* OPAL power-control events notifier */
  82 static int opal_power_control_event(struct notifier_block *nb,
  83                                         unsigned long msg_type, void *msg)
  84 {
  85         uint64_t type;
  86
  87         switch (msg_type) {
  88         case OPAL_MSG_EPOW:
  89                 if (detect_epow()) {
  90                         pr_info("EPOW msg received. Powering off system\n");
  91                         orderly_poweroff(true);
  92                 }
  93                 break;
  94         case OPAL_MSG_DPO:
  95                 pr_info("DPO msg received. Powering off system\n");
  96                 orderly_poweroff(true);
  97                 break;
  98         case OPAL_MSG_SHUTDOWN:
  99                 type = be64_to_cpu(((struct opal_msg *)msg)->params[0]);
 100                 switch (type) {
 101                 case SOFT_REBOOT:
 102                         pr_info("Reboot requested\n");
 103                         orderly_reboot();
 104                         break;
 105                 case SOFT_OFF:
 106                         pr_info("Poweroff requested\n");
 107                         orderly_poweroff(true);
 108                         break;
 109                 default:
 110                         pr_err("Unknown power-control type %llu\n", type);
 111                 }
 112                 break;
 113         default:
 114                 pr_err("Unknown OPAL message type %lu\n", msg_type);
 115         }
 116
 117         return 0;
 118 }
 119
 120 /* OPAL EPOW event notifier block */
 121 static struct notifier_block opal_epow_nb = {
 122         .notifier_call  = opal_power_control_event,
 123         .next           = NULL,
 124         .priority       = 0,
 125 };
 126
 127 /* OPAL DPO event notifier block */
 128 static struct notifier_block opal_dpo_nb = {
 129         .notifier_call  = opal_power_control_event,
 130         .next           = NULL,
 131         .priority       = 0,
 132 };
 133
 134 /* OPAL power-control event notifier block */
 135 static struct notifier_block opal_power_control_nb = {
 136         .notifier_call  = opal_power_control_event,
 137         .next           = NULL,
 138         .priority       = 0,
 139 };
 140
 141 static int __init opal_power_control_init(void)
 142 {
 143         int ret, supported = 0;
 144         struct device_node *np;
 145
 146         /* Register OPAL power-control events notifier */
 147         ret = opal_message_notifier_register(OPAL_MSG_SHUTDOWN,
 148                                                 &opal_power_control_nb);
 149         if (ret)
 150                 pr_err("Failed to register SHUTDOWN notifier, ret = %d\n", ret);
 151
 152         /* Determine OPAL EPOW, DPO support */
 153         np = of_find_node_by_path("/ibm,opal/epow");
 154         if (np) {
 155                 supported = of_device_is_compatible(np, "ibm,opal-v3-epow");
 156                 of_node_put(np);
 157         }
 158
 159         if (!supported)
 160                 return 0;
 161         pr_info("OPAL EPOW, DPO support detected.\n");
 162
 163         /* Register EPOW event notifier */
 164         ret = opal_message_notifier_register(OPAL_MSG_EPOW, &opal_epow_nb);
 165         if (ret)
 166                 pr_err("Failed to register EPOW notifier, ret = %d\n", ret);
 167
 168         /* Register DPO event notifier */
 169         ret = opal_message_notifier_register(OPAL_MSG_DPO, &opal_dpo_nb);
 170         if (ret)
 171                 pr_err("Failed to register DPO notifier, ret = %d\n", ret);
 172
 173         /* Check for any pending EPOW or DPO events. */
 174         if (poweroff_pending())
 175                 orderly_poweroff(true);
 176
 177         return 0;
 178 }
 179 machine_subsys_initcall(powernv, opal_power_control_init);