arch/sparc/kernel/sstate.c

   1 /* sstate.c: System soft state support.
   2  *
   3  * Copyright (C) 2007, 2008 David S. Miller <davem@davemloft.net>
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/notifier.h>
   8 #include <linux/reboot.h>
   9 #include <linux/init.h>
  10
  11 #include <asm/hypervisor.h>
  12 #include <asm/spitfire.h>
  13 #include <asm/oplib.h>
  14 #include <asm/head.h>
  15 #include <asm/io.h>
  16
  17 static int hv_supports_soft_state;
  18
  19 static unsigned long kimage_addr_to_ra(const char *p)
  20 {
  21         unsigned long val = (unsigned long) p;
  22
  23         return kern_base + (val - KERNBASE);
  24 }
  25
  26 static void do_set_sstate(unsigned long state, const char *msg)
  27 {
  28         unsigned long err;
  29
  30         if (!hv_supports_soft_state)
  31                 return;
  32
  33         err = sun4v_mach_set_soft_state(state, kimage_addr_to_ra(msg));
  34         if (err) {
  35                 printk(KERN_WARNING "SSTATE: Failed to set soft-state to "
  36                        "state[%lx] msg[%s], err=%lu\n",
  37                        state, msg, err);
  38         }
  39 }
  40
  41 static const char booting_msg[32] __attribute__((aligned(32))) =
  42         "Linux booting";
  43 static const char running_msg[32] __attribute__((aligned(32))) =
  44         "Linux running";
  45 static const char halting_msg[32] __attribute__((aligned(32))) =
  46         "Linux halting";
  47 static const char poweroff_msg[32] __attribute__((aligned(32))) =
  48         "Linux powering off";
  49 static const char rebooting_msg[32] __attribute__((aligned(32))) =
  50         "Linux rebooting";
  51 static const char panicing_msg[32] __attribute__((aligned(32))) =
  52         "Linux panicing";
  53
  54 static int sstate_reboot_call(struct notifier_block *np, unsigned long type, void *_unused)
  55 {
  56         const char *msg;
  57
  58         switch (type) {
  59         case SYS_DOWN:
  60         default:
  61                 msg = rebooting_msg;
  62                 break;
  63
  64         case SYS_HALT:
  65                 msg = halting_msg;
  66                 break;
  67
  68         case SYS_POWER_OFF:
  69                 msg = poweroff_msg;
  70                 break;
  71         }
  72
  73         do_set_sstate(HV_SOFT_STATE_TRANSITION, msg);
  74
  75         return NOTIFY_OK;
  76 }
  77
  78 static struct notifier_block sstate_reboot_notifier = {
  79         .notifier_call = sstate_reboot_call,
  80 };
  81
  82 static int sstate_panic_event(struct notifier_block *n, unsigned long event, void *ptr)
  83 {
  84         do_set_sstate(HV_SOFT_STATE_TRANSITION, panicing_msg);
  85
  86         return NOTIFY_DONE;
  87 }
  88
  89 static struct notifier_block sstate_panic_block = {
  90         .notifier_call  =       sstate_panic_event,
  91         .priority       =       INT_MAX,
  92 };
  93
  94 static int __init sstate_init(void)
  95 {
  96         unsigned long major, minor;
  97
  98         if (tlb_type != hypervisor)
  99                 return 0;
 100
 101         major = 1;
 102         minor = 0;
 103         if (sun4v_hvapi_register(HV_GRP_SOFT_STATE, major, &minor))
 104                 return 0;
 105
 106         hv_supports_soft_state = 1;
 107
 108         prom_sun4v_guest_soft_state();
 109
 110         do_set_sstate(HV_SOFT_STATE_TRANSITION, booting_msg);
 111
 112         atomic_notifier_chain_register(&panic_notifier_list,
 113                                        &sstate_panic_block);
 114         register_reboot_notifier(&sstate_reboot_notifier);
 115
 116         return 0;
 117 }
 118
 119 core_initcall(sstate_init);
 120
 121 static int __init sstate_running(void)
 122 {
 123         do_set_sstate(HV_SOFT_STATE_NORMAL, running_msg);
 124         return 0;
 125 }
 126
 127 late_initcall(sstate_running);