Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
[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 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         crash_save_vmcoreinfo();
123         local_irq_disable();
124         kexec_disable_iosapic();
125         machine_kexec(ia64_kimage);
126 }
127
128 void
129 kdump_cpu_freeze(struct unw_frame_info *info, void *arg)
130 {
131         int cpuid;
132         local_irq_disable();
133         cpuid = smp_processor_id();
134         crash_save_this_cpu();
135         current->thread.ksp = (__u64)info->sw - 16;
136         atomic_inc(&kdump_cpu_frozen);
137         kdump_status[cpuid] = 1;
138         mb();
139 #ifdef CONFIG_HOTPLUG_CPU
140         if (cpuid != 0)
141                 ia64_jump_to_sal(&sal_boot_rendez_state[cpuid]);
142 #endif
143         for (;;)
144                 cpu_relax();
145 }
146
147 static int
148 kdump_init_notifier(struct notifier_block *self, unsigned long val, void *data)
149 {
150         struct ia64_mca_notify_die *nd;
151         struct die_args *args = data;
152
153         if (!kdump_on_init && !kdump_on_fatal_mca)
154                 return NOTIFY_DONE;
155
156         if (!ia64_kimage) {
157                 if (val == DIE_INIT_MONARCH_LEAVE)
158                         ia64_mca_printk(KERN_NOTICE
159                                         "%s: kdump not configured\n",
160                                         __func__);
161                 return NOTIFY_DONE;
162         }
163
164         if (val != DIE_INIT_MONARCH_LEAVE &&
165             val != DIE_INIT_SLAVE_LEAVE &&
166             val != DIE_INIT_MONARCH_PROCESS &&
167             val != DIE_MCA_RENDZVOUS_LEAVE &&
168             val != DIE_MCA_MONARCH_LEAVE)
169                 return NOTIFY_DONE;
170
171         nd = (struct ia64_mca_notify_die *)args->err;
172         /* Reason code 1 means machine check rendezvous*/
173         if ((val == DIE_INIT_MONARCH_LEAVE || val == DIE_INIT_SLAVE_LEAVE
174             || val == DIE_INIT_MONARCH_PROCESS) && nd->sos->rv_rc == 1)
175                 return NOTIFY_DONE;
176
177         switch (val) {
178         case DIE_INIT_MONARCH_PROCESS:
179                 if (kdump_on_init) {
180                         atomic_set(&kdump_in_progress, 1);
181                         *(nd->monarch_cpu) = -1;
182                 }
183                 break;
184         case DIE_INIT_MONARCH_LEAVE:
185                 if (kdump_on_init)
186                         machine_kdump_on_init();
187                 break;
188         case DIE_INIT_SLAVE_LEAVE:
189                 if (atomic_read(&kdump_in_progress))
190                         unw_init_running(kdump_cpu_freeze, NULL);
191                 break;
192         case DIE_MCA_RENDZVOUS_LEAVE:
193                 if (atomic_read(&kdump_in_progress))
194                         unw_init_running(kdump_cpu_freeze, NULL);
195                 break;
196         case DIE_MCA_MONARCH_LEAVE:
197                 /* die_register->signr indicate if MCA is recoverable */
198                 if (kdump_on_fatal_mca && !args->signr) {
199                         atomic_set(&kdump_in_progress, 1);
200                         *(nd->monarch_cpu) = -1;
201                         machine_kdump_on_init();
202                 }
203                 break;
204         }
205         return NOTIFY_DONE;
206 }
207
208 #ifdef CONFIG_SYSCTL
209 static ctl_table kdump_ctl_table[] = {
210         {
211                 .ctl_name = CTL_UNNUMBERED,
212                 .procname = "kdump_on_init",
213                 .data = &kdump_on_init,
214                 .maxlen = sizeof(int),
215                 .mode = 0644,
216                 .proc_handler = &proc_dointvec,
217         },
218         {
219                 .ctl_name = CTL_UNNUMBERED,
220                 .procname = "kdump_on_fatal_mca",
221                 .data = &kdump_on_fatal_mca,
222                 .maxlen = sizeof(int),
223                 .mode = 0644,
224                 .proc_handler = &proc_dointvec,
225         },
226         { .ctl_name = 0 }
227 };
228
229 static ctl_table sys_table[] = {
230         {
231           .ctl_name = CTL_KERN,
232           .procname = "kernel",
233           .mode = 0555,
234           .child = kdump_ctl_table,
235         },
236         { .ctl_name = 0 }
237 };
238 #endif
239
240 static int
241 machine_crash_setup(void)
242 {
243         /* be notified before default_monarch_init_process */
244         static struct notifier_block kdump_init_notifier_nb = {
245                 .notifier_call = kdump_init_notifier,
246                 .priority = 1,
247         };
248         int ret;
249         if((ret = register_die_notifier(&kdump_init_notifier_nb)) != 0)
250                 return ret;
251 #ifdef CONFIG_SYSCTL
252         register_sysctl_table(sys_table);
253 #endif
254         return 0;
255 }
256
257 __initcall(machine_crash_setup);
258