arch/ia64/kernel/crash.c

   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 static int kdump_on_fatal_mca = 1;
  28
  29 static inline Elf64_Word
  30 *append_elf_note(Elf64_Word *buf, char *name, unsigned type, void *data,
  31                 size_t data_len)
  32 {
  33         struct elf_note *note = (struct elf_note *)buf;
  34         note->n_namesz = strlen(name) + 1;
  35         note->n_descsz = data_len;
  36         note->n_type   = type;
  37         buf += (sizeof(*note) + 3)/4;
  38         memcpy(buf, name, note->n_namesz);
  39         buf += (note->n_namesz + 3)/4;
  40         memcpy(buf, data, data_len);
  41         buf += (data_len + 3)/4;
  42         return buf;
  43 }
  44
  45 static void
  46 final_note(void *buf)
  47 {
  48         memset(buf, 0, sizeof(struct elf_note));
  49 }
  50
  51 extern void ia64_dump_cpu_regs(void *);
  52
  53 static DEFINE_PER_CPU(struct elf_prstatus, elf_prstatus);
  54
  55 void
  56 crash_save_this_cpu(void)
  57 {
  58         void *buf;
  59         unsigned long cfm, sof, sol;
  60
  61         int cpu = smp_processor_id();
  62         struct elf_prstatus *prstatus = &per_cpu(elf_prstatus, cpu);
  63
  64         elf_greg_t *dst = (elf_greg_t *)&(prstatus->pr_reg);
  65         memset(prstatus, 0, sizeof(*prstatus));
  66         prstatus->pr_pid = current->pid;
  67
  68         ia64_dump_cpu_regs(dst);
  69         cfm = dst[43];
  70         sol = (cfm >> 7) & 0x7f;
  71         sof = cfm & 0x7f;
  72         dst[46] = (unsigned long)ia64_rse_skip_regs((unsigned long *)dst[46],
  73                         sof - sol);
  74
  75         buf = (u64 *) per_cpu_ptr(crash_notes, cpu);
  76         if (!buf)
  77                 return;
  78         buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, prstatus,
  79                         sizeof(*prstatus));
  80         final_note(buf);
  81 }
  82
  83 #ifdef CONFIG_SMP
  84 static int
  85 kdump_wait_cpu_freeze(void)
  86 {
  87         int cpu_num = num_online_cpus() - 1;
  88         int timeout = 1000;
  89         while(timeout-- > 0) {
  90                 if (atomic_read(&kdump_cpu_frozen) == cpu_num)
  91                         return 0;
  92                 udelay(1000);
  93         }
  94         return 1;
  95 }
  96 #endif
  97
  98 void
  99 machine_crash_shutdown(struct pt_regs *pt)
 100 {
 101         /* This function is only called after the system
 102          * has paniced or is otherwise in a critical state.
 103          * The minimum amount of code to allow a kexec'd kernel
 104          * to run successfully needs to happen here.
 105          *
 106          * In practice this means shooting down the other cpus in
 107          * an SMP system.
 108          */
 109         kexec_disable_iosapic();
 110 #ifdef CONFIG_SMP
 111         kdump_smp_send_stop();
 112         /* not all cpu response to IPI, send INIT to freeze them */
 113         if (kdump_wait_cpu_freeze() && kdump_on_init)   {
 114                 kdump_smp_send_init();
 115         }
 116 #endif
 117 }
 118
 119 static void
 120 machine_kdump_on_init(void)
 121 {
 122         local_irq_disable();
 123         kexec_disable_iosapic();
 124         machine_kexec(ia64_kimage);
 125 }
 126
 127 void
 128 kdump_cpu_freeze(struct unw_frame_info *info, void *arg)
 129 {
 130         int cpuid;
 131         local_irq_disable();
 132         cpuid = smp_processor_id();
 133         crash_save_this_cpu();
 134         current->thread.ksp = (__u64)info->sw - 16;
 135         atomic_inc(&kdump_cpu_frozen);
 136         kdump_status[cpuid] = 1;
 137         mb();
 138 #ifdef CONFIG_HOTPLUG_CPU
 139         if (cpuid != 0)
 140                 ia64_jump_to_sal(&sal_boot_rendez_state[cpuid]);
 141 #endif
 142         for (;;)
 143                 cpu_relax();
 144 }
 145
 146 static int
 147 kdump_init_notifier(struct notifier_block *self, unsigned long val, void *data)
 148 {
 149         struct ia64_mca_notify_die *nd;
 150         struct die_args *args = data;
 151
 152         if (!kdump_on_init && !kdump_on_fatal_mca)
 153                 return NOTIFY_DONE;
 154
 155         if (!ia64_kimage) {
 156                 if (val == DIE_INIT_MONARCH_LEAVE)
 157                         ia64_mca_printk(KERN_NOTICE
 158                                         "%s: kdump not configured\n",
 159                                         __func__);
 160                 return NOTIFY_DONE;
 161         }
 162
 163         if (val != DIE_INIT_MONARCH_LEAVE &&
 164             val != DIE_INIT_SLAVE_LEAVE &&
 165             val != DIE_INIT_MONARCH_PROCESS &&
 166             val != DIE_MCA_RENDZVOUS_LEAVE &&
 167             val != DIE_MCA_MONARCH_LEAVE)
 168                 return NOTIFY_DONE;
 169
 170         nd = (struct ia64_mca_notify_die *)args->err;
 171         /* Reason code 1 means machine check rendezvous*/
 172         if ((val == DIE_INIT_MONARCH_LEAVE || val == DIE_INIT_SLAVE_LEAVE
 173             || val == DIE_INIT_MONARCH_PROCESS) && nd->sos->rv_rc == 1)
 174                 return NOTIFY_DONE;
 175
 176         switch (val) {
 177                 case DIE_INIT_MONARCH_PROCESS:
 178                         if (kdump_on_init) {
 179                                 atomic_set(&kdump_in_progress, 1);
 180                                 *(nd->monarch_cpu) = -1;
 181                         }
 182                         break;
 183                 case DIE_INIT_MONARCH_LEAVE:
 184                         if (kdump_on_init)
 185                                 machine_kdump_on_init();
 186                         break;
 187                 case DIE_INIT_SLAVE_LEAVE:
 188                         if (atomic_read(&kdump_in_progress))
 189                                 unw_init_running(kdump_cpu_freeze, NULL);
 190                         break;
 191                 case DIE_MCA_RENDZVOUS_LEAVE:
 192                         if (atomic_read(&kdump_in_progress))
 193                                 unw_init_running(kdump_cpu_freeze, NULL);
 194                         break;
 195                 case DIE_MCA_MONARCH_LEAVE:
 196                         /* die_register->signr indicate if MCA is recoverable */
 197                         if (kdump_on_fatal_mca && !args->signr) {
 198                                 atomic_set(&kdump_in_progress, 1);
 199                                 *(nd->monarch_cpu) = -1;
 200                                 machine_kdump_on_init();
 201                         }
 202                         break;
 203         }
 204         return NOTIFY_DONE;
 205 }
 206
 207 #ifdef CONFIG_SYSCTL
 208 static ctl_table kdump_ctl_table[] = {
 209         {
 210                 .ctl_name = CTL_UNNUMBERED,
 211                 .procname = "kdump_on_init",
 212                 .data = &kdump_on_init,
 213                 .maxlen = sizeof(int),
 214                 .mode = 0644,
 215                 .proc_handler = &proc_dointvec,
 216         },
 217         {
 218                 .ctl_name = CTL_UNNUMBERED,
 219                 .procname = "kdump_on_fatal_mca",
 220                 .data = &kdump_on_fatal_mca,
 221                 .maxlen = sizeof(int),
 222                 .mode = 0644,
 223                 .proc_handler = &proc_dointvec,
 224         },
 225         { .ctl_name = 0 }
 226 };
 227
 228 static ctl_table sys_table[] = {
 229         {
 230           .ctl_name = CTL_KERN,
 231           .procname = "kernel",
 232           .mode = 0555,
 233           .child = kdump_ctl_table,
 234         },
 235         { .ctl_name = 0 }
 236 };
 237 #endif
 238
 239 static int
 240 machine_crash_setup(void)
 241 {
 242         /* be notified before default_monarch_init_process */
 243         static struct notifier_block kdump_init_notifier_nb = {
 244                 .notifier_call = kdump_init_notifier,
 245                 .priority = 1,
 246         };
 247         int ret;
 248         if((ret = register_die_notifier(&kdump_init_notifier_nb)) != 0)
 249                 return ret;
 250 #ifdef CONFIG_SYSCTL
 251         register_sysctl_table(sys_table);
 252 #endif
 253         return 0;
 254 }
 255
 256 __initcall(machine_crash_setup);
 257