arch/sparc/kernel/sstate.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* sstate.c: System soft state support.
   3  *
   4  * Copyright (C) 2007, 2008 David S. Miller <davem@davemloft.net>
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/notifier.h>
   9 #include <linux/reboot.h>
  10 #include <linux/init.h>
  11
  12 #include <asm/hypervisor.h>
  13 #include <asm/spitfire.h>
  14 #include <asm/oplib.h>
  15 #include <asm/head.h>
  16 #include <asm/io.h>
  17
  18 #include "kernel.h"
  19
  20 static int hv_supports_soft_state;
  21
  22 static void do_set_sstate(unsigned long state, const char *msg)
  23 {
  24         unsigned long err;
  25
  26         if (!hv_supports_soft_state)
  27                 return;
  28
  29         err = sun4v_mach_set_soft_state(state, kimage_addr_to_ra(msg));
  30         if (err) {
  31                 printk(KERN_WARNING "SSTATE: Failed to set soft-state to "
  32                        "state[%lx] msg[%s], err=%lu\n",
  33                        state, msg, err);
  34         }
  35 }
  36
  37 static const char booting_msg[32] __attribute__((aligned(32))) =
  38         "Linux booting";
  39 static const char running_msg[32] __attribute__((aligned(32))) =
  40         "Linux running";
  41 static const char halting_msg[32] __attribute__((aligned(32))) =
  42         "Linux halting";
  43 static const char poweroff_msg[32] __attribute__((aligned(32))) =
  44         "Linux powering off";
  45 static const char rebooting_msg[32] __attribute__((aligned(32))) =
  46         "Linux rebooting";
  47 static const char panicking_msg[32] __attribute__((aligned(32))) =
  48         "Linux panicking";
  49
  50 static int sstate_reboot_call(struct notifier_block *np, unsigned long type, void *_unused)
  51 {
  52         const char *msg;
  53
  54         switch (type) {
  55         case SYS_DOWN:
  56         default:
  57                 msg = rebooting_msg;
  58                 break;
  59
  60         case SYS_HALT:
  61                 msg = halting_msg;
  62                 break;
  63
  64         case SYS_POWER_OFF:
  65                 msg = poweroff_msg;
  66                 break;
  67         }
  68
  69         do_set_sstate(HV_SOFT_STATE_TRANSITION, msg);
  70
  71         return NOTIFY_OK;
  72 }
  73
  74 static struct notifier_block sstate_reboot_notifier = {
  75         .notifier_call = sstate_reboot_call,
  76 };
  77
  78 static int sstate_panic_event(struct notifier_block *n, unsigned long event, void *ptr)
  79 {
  80         do_set_sstate(HV_SOFT_STATE_TRANSITION, panicking_msg);
  81
  82         return NOTIFY_DONE;
  83 }
  84
  85 static struct notifier_block sstate_panic_block = {
  86         .notifier_call  =       sstate_panic_event,
  87         .priority       =       INT_MAX,
  88 };
  89
  90 static int __init sstate_init(void)
  91 {
  92         unsigned long major, minor;
  93
  94         if (tlb_type != hypervisor)
  95                 return 0;
  96
  97         major = 1;
  98         minor = 0;
  99         if (sun4v_hvapi_register(HV_GRP_SOFT_STATE, major, &minor))
 100                 return 0;
 101
 102         hv_supports_soft_state = 1;
 103
 104         prom_sun4v_guest_soft_state();
 105
 106         do_set_sstate(HV_SOFT_STATE_TRANSITION, booting_msg);
 107
 108         atomic_notifier_chain_register(&panic_notifier_list,
 109                                        &sstate_panic_block);
 110         register_reboot_notifier(&sstate_reboot_notifier);
 111
 112         return 0;
 113 }
 114
 115 core_initcall(sstate_init);
 116
 117 static int __init sstate_running(void)
 118 {
 119         do_set_sstate(HV_SOFT_STATE_NORMAL, running_msg);
 120         return 0;
 121 }
 122
 123 late_initcall(sstate_running);