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
23int kdump_status[NR_CPUS];
24static atomic_t kdump_cpu_frozen;
25atomic_t kdump_in_progress;
26static int kdump_on_init = 1;
27
28static 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
44static void
45final_note(void *buf)
46{
47	memset(buf, 0, sizeof(struct elf_note));
48}
49
50extern void ia64_dump_cpu_regs(void *);
51
52static DEFINE_PER_CPU(struct elf_prstatus, elf_prstatus);
53
54void
55crash_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
83static int
84kdump_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
97void
98machine_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
118static void
119machine_kdump_on_init(void)
120{
121	if (!ia64_kimage) {
122		printk(KERN_NOTICE "machine_kdump_on_init(): "
123				"kdump not configured\n");
124		return;
125	}
126	local_irq_disable();
127	kexec_disable_iosapic();
128	machine_kexec(ia64_kimage);
129}
130
131void
132kdump_cpu_freeze(struct unw_frame_info *info, void *arg)
133{
134	int cpuid;
135	local_irq_disable();
136	cpuid = smp_processor_id();
137	crash_save_this_cpu();
138	current->thread.ksp = (__u64)info->sw - 16;
139	atomic_inc(&kdump_cpu_frozen);
140	kdump_status[cpuid] = 1;
141	mb();
142#ifdef CONFIG_HOTPLUG_CPU
143	if (cpuid != 0)
144		ia64_jump_to_sal(&sal_boot_rendez_state[cpuid]);
145#endif
146	for (;;)
147		cpu_relax();
148}
149
150static int
151kdump_init_notifier(struct notifier_block *self, unsigned long val, void *data)
152{
153	struct ia64_mca_notify_die *nd;
154	struct die_args *args = data;
155
156	if (!kdump_on_init)
157		return NOTIFY_DONE;
158
159	if (val != DIE_INIT_MONARCH_LEAVE &&
160	    val != DIE_INIT_SLAVE_LEAVE &&
161	    val != DIE_INIT_MONARCH_PROCESS &&
162	    val != DIE_MCA_RENDZVOUS_LEAVE &&
163	    val != DIE_MCA_MONARCH_LEAVE)
164		return NOTIFY_DONE;
165
166	nd = (struct ia64_mca_notify_die *)args->err;
167	/* Reason code 1 means machine check rendezvous*/
168	if ((val == DIE_INIT_MONARCH_LEAVE || val == DIE_INIT_SLAVE_LEAVE
169	    || val == DIE_INIT_MONARCH_PROCESS) && nd->sos->rv_rc == 1)
170		return NOTIFY_DONE;
171
172	switch (val) {
173		case DIE_INIT_MONARCH_PROCESS:
174			atomic_set(&kdump_in_progress, 1);
175			*(nd->monarch_cpu) = -1;
176			break;
177		case DIE_INIT_MONARCH_LEAVE:
178			machine_kdump_on_init();
179			break;
180		case DIE_INIT_SLAVE_LEAVE:
181			if (atomic_read(&kdump_in_progress))
182				unw_init_running(kdump_cpu_freeze, NULL);
183			break;
184		case DIE_MCA_RENDZVOUS_LEAVE:
185			if (atomic_read(&kdump_in_progress))
186				unw_init_running(kdump_cpu_freeze, NULL);
187			break;
188		case DIE_MCA_MONARCH_LEAVE:
189		     /* die_register->signr indicate if MCA is recoverable */
190			if (!args->signr)
191				machine_kdump_on_init();
192			break;
193	}
194	return NOTIFY_DONE;
195}
196
197#ifdef CONFIG_SYSCTL
198static ctl_table kdump_on_init_table[] = {
199	{
200		.ctl_name = CTL_UNNUMBERED,
201		.procname = "kdump_on_init",
202		.data = &kdump_on_init,
203		.maxlen = sizeof(int),
204		.mode = 0644,
205		.proc_handler = &proc_dointvec,
206	},
207	{ .ctl_name = 0 }
208};
209
210static ctl_table sys_table[] = {
211	{
212	  .ctl_name = CTL_KERN,
213	  .procname = "kernel",
214	  .mode = 0555,
215	  .child = kdump_on_init_table,
216	},
217	{ .ctl_name = 0 }
218};
219#endif
220
221static int
222machine_crash_setup(void)
223{
224	/* be notified before default_monarch_init_process */
225	static struct notifier_block kdump_init_notifier_nb = {
226		.notifier_call = kdump_init_notifier,
227		.priority = 1,
228	};
229	int ret;
230	if((ret = register_die_notifier(&kdump_init_notifier_nb)) != 0)
231		return ret;
232#ifdef CONFIG_SYSCTL
233	register_sysctl_table(sys_table);
234#endif
235	return 0;
236}
237
238__initcall(machine_crash_setup);
239