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