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   1 /*
   2  * arch/ia64/kernel/crash.c
   3  *
   4  * Architecture specific (ia64) functions for kexec based crash dumps.
   5  *
   6  * Created by: Khalid Aziz <khalid.aziz@hp.com>
   7  * Copyright (C) 2005 Hewlett-Packard Development Company, L.P.
   8  * Copyright (C) 2005 Intel Corp        Zou Nan hai <nanhai.zou@intel.com>
   9  *
  10  */
  11 #include <linux/smp.h>
  12 #include <linux/delay.h>
  13 #include <linux/crash_dump.h>
  14 #include <linux/bootmem.h>
  15 #include <linux/kexec.h>
  16 #include <linux/elfcore.h>
  17 #include <linux/sysctl.h>
  18 #include <linux/init.h>
  19 #include <linux/kdebug.h>
  20
  21 #include <asm/mca.h>
  22
  23 int kdump_status[NR_CPUS];
  24 static atomic_t kdump_cpu_frozen;
  25 atomic_t kdump_in_progress;
  26 static int kdump_on_init = 1;
  27
  28 static inline Elf64_Word
  29 *append_elf_note(Elf64_Word *buf, char *name, unsigned type, void *data,
  30                 size_t data_len)
  31 {
  32         struct elf_note *note = (struct elf_note *)buf;
  33         note->n_namesz = strlen(name) + 1;
  34         note->n_descsz = data_len;
  35         note->n_type   = type;
  36         buf += (sizeof(*note) + 3)/4;
  37         memcpy(buf, name, note->n_namesz);
  38         buf += (note->n_namesz + 3)/4;
  39         memcpy(buf, data, data_len);
  40         buf += (data_len + 3)/4;
  41         return buf;
  42 }
  43
  44 static void
  45 final_note(void *buf)
  46 {
  47         memset(buf, 0, sizeof(struct elf_note));
  48 }
  49
  50 extern void ia64_dump_cpu_regs(void *);
  51
  52 static DEFINE_PER_CPU(struct elf_prstatus, elf_prstatus);
  53
  54 void
  55 crash_save_this_cpu(void)
  56 {
  57         void *buf;
  58         unsigned long cfm, sof, sol;
  59
  60         int cpu = smp_processor_id();
  61         struct elf_prstatus *prstatus = &per_cpu(elf_prstatus, cpu);
  62
  63         elf_greg_t *dst = (elf_greg_t *)&(prstatus->pr_reg);
  64         memset(prstatus, 0, sizeof(*prstatus));
  65         prstatus->pr_pid = current->pid;
  66
  67         ia64_dump_cpu_regs(dst);
  68         cfm = dst[43];
  69         sol = (cfm >> 7) & 0x7f;
  70         sof = cfm & 0x7f;
  71         dst[46] = (unsigned long)ia64_rse_skip_regs((unsigned long *)dst[46],
  72                         sof - sol);
  73
  74         buf = (u64 *) per_cpu_ptr(crash_notes, cpu);
  75         if (!buf)
  76                 return;
  77         buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, prstatus,
  78                         sizeof(*prstatus));
  79         final_note(buf);
  80 }
  81
  82 #ifdef CONFIG_SMP
  83 static int
  84 kdump_wait_cpu_freeze(void)
  85 {
  86         int cpu_num = num_online_cpus() - 1;
  87         int timeout = 1000;
  88         while(timeout-- > 0) {
  89                 if (atomic_read(&kdump_cpu_frozen) == cpu_num)
  90                         return 0;
  91                 udelay(1000);
  92         }
  93         return 1;
  94 }
  95 #endif
  96
  97 void
  98 machine_crash_shutdown(struct pt_regs *pt)
  99 {
 100         /* This function is only called after the system
 101          * has paniced or is otherwise in a critical state.
 102          * The minimum amount of code to allow a kexec'd kernel
 103          * to run successfully needs to happen here.
 104          *
 105          * In practice this means shooting down the other cpus in
 106          * an SMP system.
 107          */
 108         kexec_disable_iosapic();
 109 #ifdef CONFIG_SMP
 110         kdump_smp_send_stop();
 111         /* not all cpu response to IPI, send INIT to freeze them */
 112         if (kdump_wait_cpu_freeze() && kdump_on_init)   {
 113                 kdump_smp_send_init();
 114         }
 115 #endif
 116 }
 117
 118 static void
 119 machine_kdump_on_init(void)
 120 {
 121         local_irq_disable();
 122         kexec_disable_iosapic();
 123         machine_kexec(ia64_kimage);
 124 }
 125
 126 void
 127 kdump_cpu_freeze(struct unw_frame_info *info, void *arg)
 128 {
 129         int cpuid;
 130         local_irq_disable();
 131         cpuid = smp_processor_id();
 132         crash_save_this_cpu();
 133         current->thread.ksp = (__u64)info->sw - 16;
 134         atomic_inc(&kdump_cpu_frozen);
 135         kdump_status[cpuid] = 1;
 136         mb();
 137 #ifdef CONFIG_HOTPLUG_CPU
 138         if (cpuid != 0)
 139                 ia64_jump_to_sal(&sal_boot_rendez_state[cpuid]);
 140 #endif
 141         for (;;)
 142                 cpu_relax();
 143 }
 144
 145 static int
 146 kdump_init_notifier(struct notifier_block *self, unsigned long val, void *data)
 147 {
 148         struct ia64_mca_notify_die *nd;
 149         struct die_args *args = data;
 150
 151         if (!kdump_on_init)
 152                 return NOTIFY_DONE;
 153
 154         if (!ia64_kimage) {
 155                 if (val == DIE_INIT_MONARCH_LEAVE)
 156                         ia64_mca_printk(KERN_NOTICE
 157                                         "%s: kdump not configured\n",
 158                                         __func__);
 159                 return NOTIFY_DONE;
 160         }
 161
 162         if (val != DIE_INIT_MONARCH_LEAVE &&
 163             val != DIE_INIT_SLAVE_LEAVE &&
 164             val != DIE_INIT_MONARCH_PROCESS &&
 165             val != DIE_MCA_RENDZVOUS_LEAVE &&
 166             val != DIE_MCA_MONARCH_LEAVE)
 167                 return NOTIFY_DONE;
 168
 169         nd = (struct ia64_mca_notify_die *)args->err;
 170         /* Reason code 1 means machine check rendezvous*/
 171         if ((val == DIE_INIT_MONARCH_LEAVE || val == DIE_INIT_SLAVE_LEAVE
 172             || val == DIE_INIT_MONARCH_PROCESS) && nd->sos->rv_rc == 1)
 173                 return NOTIFY_DONE;
 174
 175         switch (val) {
 176                 case DIE_INIT_MONARCH_PROCESS:
 177                         atomic_set(&kdump_in_progress, 1);
 178                         *(nd->monarch_cpu) = -1;
 179                         break;
 180                 case DIE_INIT_MONARCH_LEAVE:
 181                         machine_kdump_on_init();
 182                         break;
 183                 case DIE_INIT_SLAVE_LEAVE:
 184                         if (atomic_read(&kdump_in_progress))
 185                                 unw_init_running(kdump_cpu_freeze, NULL);
 186                         break;
 187                 case DIE_MCA_RENDZVOUS_LEAVE:
 188                         if (atomic_read(&kdump_in_progress))
 189                                 unw_init_running(kdump_cpu_freeze, NULL);
 190                         break;
 191                 case DIE_MCA_MONARCH_LEAVE:
 192                      /* die_register->signr indicate if MCA is recoverable */
 193                         if (!args->signr)
 194                                 machine_kdump_on_init();
 195                         break;
 196         }
 197         return NOTIFY_DONE;
 198 }
 199
 200 #ifdef CONFIG_SYSCTL
 201 static ctl_table kdump_on_init_table[] = {
 202         {
 203                 .ctl_name = CTL_UNNUMBERED,
 204                 .procname = "kdump_on_init",
 205                 .data = &kdump_on_init,
 206                 .maxlen = sizeof(int),
 207                 .mode = 0644,
 208                 .proc_handler = &proc_dointvec,
 209         },
 210         { .ctl_name = 0 }
 211 };
 212
 213 static ctl_table sys_table[] = {
 214         {
 215           .ctl_name = CTL_KERN,
 216           .procname = "kernel",
 217           .mode = 0555,
 218           .child = kdump_on_init_table,
 219         },
 220         { .ctl_name = 0 }
 221 };
 222 #endif
 223
 224 static int
 225 machine_crash_setup(void)
 226 {
 227         /* be notified before default_monarch_init_process */
 228         static struct notifier_block kdump_init_notifier_nb = {
 229                 .notifier_call = kdump_init_notifier,
 230                 .priority = 1,
 231         };
 232         int ret;
 233         if((ret = register_die_notifier(&kdump_init_notifier_nb)) != 0)
 234                 return ret;
 235 #ifdef CONFIG_SYSCTL
 236         register_sysctl_table(sys_table);
 237 #endif
 238         return 0;
 239 }
 240
 241 __initcall(machine_crash_setup);
 242