aboutsummaryrefslogtreecommitdiff
path: root/arch/x86_64/kernel/reboot.c
blob: 368db2b9c5ac3977b0ec32edabe2aec9359df6de (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
/* Various gunk just to reboot the machine. */ 
#include <linux/module.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/ctype.h>
#include <linux/string.h>
#include <linux/pm.h>
#include <linux/kdebug.h>
#include <linux/sched.h>
#include <asm/io.h>
#include <asm/delay.h>
#include <asm/hw_irq.h>
#include <asm/system.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/apic.h>
#include <asm/iommu.h>

/*
 * Power off function, if any
 */
void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);

static long no_idt[3];
static enum { 
	BOOT_TRIPLE = 't',
	BOOT_KBD = 'k'
} reboot_type = BOOT_KBD;
static int reboot_mode = 0;
int reboot_force;

/* reboot=t[riple] | k[bd] [, [w]arm | [c]old]
   warm   Don't set the cold reboot flag
   cold   Set the cold reboot flag
   triple Force a triple fault (init)
   kbd    Use the keyboard controller. cold reset (default)
   force  Avoid anything that could hang.
 */ 
static int __init reboot_setup(char *str)
{
	for (;;) {
		switch (*str) {
		case 'w': 
			reboot_mode = 0x1234;
			break;

		case 'c':
			reboot_mode = 0;
			break;

		case 't':
		case 'b':
		case 'k':
			reboot_type = *str;
			break;
		case 'f':
			reboot_force = 1;
			break;
		}
		if((str = strchr(str,',')) != NULL)
			str++;
		else
			break;
	}
	return 1;
}

__setup("reboot=", reboot_setup);

static inline void kb_wait(void)
{
	int i;

	for (i=0; i<0x10000; i++)
		if ((inb_p(0x64) & 0x02) == 0)
			break;
}

void machine_shutdown(void)
{
	unsigned long flags;

	/* Stop the cpus and apics */
#ifdef CONFIG_SMP
	int reboot_cpu_id;

	/* The boot cpu is always logical cpu 0 */
	reboot_cpu_id = 0;

	/* Make certain the cpu I'm about to reboot on is online */
	if (!cpu_isset(reboot_cpu_id, cpu_online_map)) {
		reboot_cpu_id = smp_processor_id();
	}

	/* Make certain I only run on the appropriate processor */
	set_cpus_allowed(current, cpumask_of_cpu(reboot_cpu_id));

	/* O.K Now that I'm on the appropriate processor,
	 * stop all of the others.
	 */
	smp_send_stop();
#endif

	local_irq_save(flags);

#ifndef CONFIG_SMP
	disable_local_APIC();
#endif

	disable_IO_APIC();

	local_irq_restore(flags);

	pci_iommu_shutdown();
}

void machine_emergency_restart(void)
{
	int i;

	/* Tell the BIOS if we want cold or warm reboot */
	*((unsigned short *)__va(0x472)) = reboot_mode;
       
	for (;;) {
		/* Could also try the reset bit in the Hammer NB */
		switch (reboot_type) { 
		case BOOT_KBD:
		for (i=0; i<10; i++) {
			kb_wait();
			udelay(50);
			outb(0xfe,0x64);         /* pulse reset low */
			udelay(50);
		}

		case BOOT_TRIPLE: 
			__asm__ __volatile__("lidt (%0)": :"r" (&no_idt));
			__asm__ __volatile__("int3");

			reboot_type = BOOT_KBD;
			break;
		}      
	}      
}

void machine_restart(char * __unused)
{
	printk("machine restart\n");

	if (!reboot_force) {
		machine_shutdown();
	}
	machine_emergency_restart();
}

void machine_halt(void)
{
}

void machine_power_off(void)
{
	if (pm_power_off) {
		if (!reboot_force) {
			machine_shutdown();
		}
		pm_power_off();
	}
}