Merge master.kernel.org:/home/rmk/linux-2.6-arm
[linux-2.6] / 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
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