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28#include <linux/nodemask.h>
29#include <linux/export.h>
30#include <linux/mmzone.h>
31#include <linux/init.h>
32#include <linux/smp.h>
33#include <linux/irq.h>
34#include <asm/cpu.h>
35
36static DEFINE_PER_CPU(struct x86_cpu, cpu_devices);
37
38#ifdef CONFIG_HOTPLUG_CPU
39
40#ifdef CONFIG_BOOTPARAM_HOTPLUG_CPU0
41static int cpu0_hotpluggable = 1;
42#else
43static int cpu0_hotpluggable;
44static int __init enable_cpu0_hotplug(char *str)
45{
46 cpu0_hotpluggable = 1;
47 return 1;
48}
49
50__setup("cpu0_hotplug", enable_cpu0_hotplug);
51#endif
52
53#ifdef CONFIG_DEBUG_HOTPLUG_CPU0
54
55
56
57
58
59
60int __ref _debug_hotplug_cpu(int cpu, int action)
61{
62 struct device *dev = get_cpu_device(cpu);
63 int ret;
64
65 if (!cpu_is_hotpluggable(cpu))
66 return -EINVAL;
67
68 cpu_hotplug_driver_lock();
69
70 switch (action) {
71 case 0:
72 ret = cpu_down(cpu);
73 if (!ret) {
74 pr_info("CPU %u is now offline\n", cpu);
75 kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
76 } else
77 pr_debug("Can't offline CPU%d.\n", cpu);
78 break;
79 case 1:
80 ret = cpu_up(cpu);
81 if (!ret)
82 kobject_uevent(&dev->kobj, KOBJ_ONLINE);
83 else
84 pr_debug("Can't online CPU%d.\n", cpu);
85 break;
86 default:
87 ret = -EINVAL;
88 }
89
90 cpu_hotplug_driver_unlock();
91
92 return ret;
93}
94
95static int __init debug_hotplug_cpu(void)
96{
97 _debug_hotplug_cpu(0, 0);
98 return 0;
99}
100
101late_initcall_sync(debug_hotplug_cpu);
102#endif
103
104int __ref arch_register_cpu(int num)
105{
106 struct cpuinfo_x86 *c = &cpu_data(num);
107
108
109
110
111
112 if (c->x86_vendor != X86_VENDOR_INTEL)
113 cpu0_hotpluggable = 0;
114
115
116
117
118
119
120
121
122
123 if (num == 0 && cpu0_hotpluggable) {
124 unsigned int irq;
125
126
127
128
129 for_each_active_irq(irq) {
130 if (!IO_APIC_IRQ(irq) && irq_has_action(irq)) {
131 cpu0_hotpluggable = 0;
132 break;
133 }
134 }
135 }
136 if (num || cpu0_hotpluggable)
137 per_cpu(cpu_devices, num).cpu.hotpluggable = 1;
138
139 return register_cpu(&per_cpu(cpu_devices, num).cpu, num);
140}
141EXPORT_SYMBOL(arch_register_cpu);
142
143void arch_unregister_cpu(int num)
144{
145 unregister_cpu(&per_cpu(cpu_devices, num).cpu);
146}
147EXPORT_SYMBOL(arch_unregister_cpu);
148#else
149
150static int __init arch_register_cpu(int num)
151{
152 return register_cpu(&per_cpu(cpu_devices, num).cpu, num);
153}
154#endif
155
156static int __init topology_init(void)
157{
158 int i;
159
160#ifdef CONFIG_NUMA
161 for_each_online_node(i)
162 register_one_node(i);
163#endif
164
165 for_each_present_cpu(i)
166 arch_register_cpu(i);
167
168 return 0;
169}
170subsys_initcall(topology_init);
171