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1 /* Various gunk just to reboot the machine. */
2 #include <linux/module.h>
3 #include <linux/reboot.h>
4 #include <linux/init.h>
5 #include <linux/smp.h>
6 #include <linux/kernel.h>
7 #include <linux/ctype.h>
8 #include <linux/string.h>
9 #include <asm/io.h>
10 #include <asm/kdebug.h>
11 #include <asm/delay.h>
12 #include <asm/hw_irq.h>
13 #include <asm/system.h>
14 #include <asm/pgtable.h>
15 #include <asm/tlbflush.h>
16 #include <asm/apic.h>
17
18 /*
19 * Power off function, if any
20 */
21 void (*pm_power_off)(void);
22
23 static long no_idt[3];
24 static enum {
25 BOOT_TRIPLE = 't',
26 BOOT_KBD = 'k'
27 } reboot_type = BOOT_KBD;
28 static int reboot_mode = 0;
29 int reboot_force;
30
31 /* reboot=t[riple] | k[bd] [, [w]arm | [c]old]
32 warm Don't set the cold reboot flag
33 cold Set the cold reboot flag
34 triple Force a triple fault (init)
35 kbd Use the keyboard controller. cold reset (default)
36 force Avoid anything that could hang.
37 */
38 static int __init reboot_setup(char *str)
39 {
40 for (;;) {
41 switch (*str) {
42 case 'w':
43 reboot_mode = 0x1234;
44 break;
45
46 case 'c':
47 reboot_mode = 0;
48 break;
49
50 case 't':
51 case 'b':
52 case 'k':
53 reboot_type = *str;
54 break;
55 case 'f':
56 reboot_force = 1;
57 break;
58 }
59 if((str = strchr(str,',')) != NULL)
60 str++;
61 else
62 break;
63 }
64 return 1;
65 }
66
67 __setup("reboot=", reboot_setup);
68
69 #ifdef CONFIG_SMP
70 static void smp_halt(void)
71 {
72 int cpuid = safe_smp_processor_id();
73 static int first_entry = 1;
74
75 if (reboot_force)
76 return;
77
78 if (first_entry) {
79 first_entry = 0;
80 smp_call_function((void *)machine_restart, NULL, 1, 0);
81 }
82
83 smp_stop_cpu();
84
85 /* AP calling this. Just halt */
86 if (cpuid != boot_cpu_id) {
87 for (;;)
88 asm("hlt");
89 }
90
91 /* Wait for all other CPUs to have run smp_stop_cpu */
92 while (!cpus_empty(cpu_online_map))
93 rep_nop();
94 }
95 #endif
96
97 static inline void kb_wait(void)
98 {
99 int i;
100
101 for (i=0; i<0x10000; i++)
102 if ((inb_p(0x64) & 0x02) == 0)
103 break;
104 }
105
106 void machine_restart(char * __unused)
107 {
108 int i;
109
110 printk("machine restart\n");
111
112 #ifdef CONFIG_SMP
113 smp_halt();
114 #endif
115
116 if (!reboot_force) {
117 local_irq_disable();
118 #ifndef CONFIG_SMP
119 disable_local_APIC();
120 #endif
121 disable_IO_APIC();
122 local_irq_enable();
123 }
124
125 /* Tell the BIOS if we want cold or warm reboot */
126 *((unsigned short *)__va(0x472)) = reboot_mode;
127
128 for (;;) {
129 /* Could also try the reset bit in the Hammer NB */
130 switch (reboot_type) {
131 case BOOT_KBD:
132 for (i=0; i<100; i++) {
133 kb_wait();
134 udelay(50);
135 outb(0xfe,0x64); /* pulse reset low */
136 udelay(50);
137 }
138
139 case BOOT_TRIPLE:
140 __asm__ __volatile__("lidt (%0)": :"r" (&no_idt));
141 __asm__ __volatile__("int3");
142
143 reboot_type = BOOT_KBD;
144 break;
145 }
146 }
147 }
148
149 EXPORT_SYMBOL(machine_restart);
150
151 void machine_halt(void)
152 {
153 }
154
155 EXPORT_SYMBOL(machine_halt);
156
157 void machine_power_off(void)
158 {
159 if (pm_power_off)
160 pm_power_off();
161 }
162
163 EXPORT_SYMBOL(machine_power_off);