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Commit | Line | Data |
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1da177e4 | 1 | /* |
835c34a1 | 2 | * Populate sysfs with topology information |
1da177e4 LT |
3 | * |
4 | * Written by: Matthew Dobson, IBM Corporation | |
5 | * Original Code: Paul Dorwin, IBM Corporation, Patrick Mochel, OSDL | |
6 | * | |
7 | * Copyright (C) 2002, IBM Corp. | |
8 | * | |
9c869eda | 9 | * All rights reserved. |
1da177e4 LT |
10 | * |
11 | * This program is free software; you can redistribute it and/or modify | |
12 | * it under the terms of the GNU General Public License as published by | |
13 | * the Free Software Foundation; either version 2 of the License, or | |
14 | * (at your option) any later version. | |
15 | * | |
16 | * This program is distributed in the hope that it will be useful, but | |
17 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or | |
19 | * NON INFRINGEMENT. See the GNU General Public License for more | |
20 | * details. | |
21 | * | |
22 | * You should have received a copy of the GNU General Public License | |
23 | * along with this program; if not, write to the Free Software | |
24 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
25 | * | |
26 | * Send feedback to <colpatch@us.ibm.com> | |
27 | */ | |
1da177e4 | 28 | #include <linux/nodemask.h> |
69c60c88 | 29 | #include <linux/export.h> |
aada06c9 | 30 | #include <linux/mmzone.h> |
271eb5c5 JSR |
31 | #include <linux/init.h> |
32 | #include <linux/smp.h> | |
4d25031a | 33 | #include <linux/irq.h> |
1da177e4 LT |
34 | #include <asm/cpu.h> |
35 | ||
30964d54 | 36 | static DEFINE_PER_CPU(struct x86_cpu, cpu_devices); |
1da177e4 | 37 | |
3eaf5efa | 38 | #ifdef CONFIG_HOTPLUG_CPU |
4d25031a FY |
39 | |
40 | #ifdef CONFIG_BOOTPARAM_HOTPLUG_CPU0 | |
41 | static int cpu0_hotpluggable = 1; | |
42 | #else | |
43 | static int cpu0_hotpluggable; | |
44 | static 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 | ||
a71c8bc5 FY |
53 | #ifdef CONFIG_DEBUG_HOTPLUG_CPU0 |
54 | /* | |
55 | * This function offlines a CPU as early as possible and allows userspace to | |
56 | * boot up without the CPU. The CPU can be onlined back by user after boot. | |
57 | * | |
58 | * This is only called for debugging CPU offline/online feature. | |
59 | */ | |
4daa832d | 60 | int _debug_hotplug_cpu(int cpu, int action) |
a71c8bc5 FY |
61 | { |
62 | struct device *dev = get_cpu_device(cpu); | |
63 | int ret; | |
64 | ||
65 | if (!cpu_is_hotpluggable(cpu)) | |
66 | return -EINVAL; | |
67 | ||
574b851e | 68 | lock_device_hotplug(); |
a71c8bc5 FY |
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); | |
f6913f99 | 75 | dev->offline = true; |
a71c8bc5 FY |
76 | kobject_uevent(&dev->kobj, KOBJ_OFFLINE); |
77 | } else | |
78 | pr_debug("Can't offline CPU%d.\n", cpu); | |
79 | break; | |
80 | case 1: | |
81 | ret = cpu_up(cpu); | |
f6913f99 TK |
82 | if (!ret) { |
83 | dev->offline = false; | |
a71c8bc5 | 84 | kobject_uevent(&dev->kobj, KOBJ_ONLINE); |
f6913f99 | 85 | } else { |
a71c8bc5 | 86 | pr_debug("Can't online CPU%d.\n", cpu); |
f6913f99 | 87 | } |
a71c8bc5 FY |
88 | break; |
89 | default: | |
90 | ret = -EINVAL; | |
91 | } | |
92 | ||
574b851e | 93 | unlock_device_hotplug(); |
a71c8bc5 FY |
94 | |
95 | return ret; | |
96 | } | |
97 | ||
98 | static int __init debug_hotplug_cpu(void) | |
99 | { | |
100 | _debug_hotplug_cpu(0, 0); | |
101 | return 0; | |
102 | } | |
103 | ||
104 | late_initcall_sync(debug_hotplug_cpu); | |
105 | #endif /* CONFIG_DEBUG_HOTPLUG_CPU0 */ | |
106 | ||
4daa832d | 107 | int arch_register_cpu(int num) |
76b67ed9 | 108 | { |
4d25031a FY |
109 | struct cpuinfo_x86 *c = &cpu_data(num); |
110 | ||
111 | /* | |
112 | * Currently CPU0 is only hotpluggable on Intel platforms. Other | |
113 | * vendors can add hotplug support later. | |
114 | */ | |
115 | if (c->x86_vendor != X86_VENDOR_INTEL) | |
116 | cpu0_hotpluggable = 0; | |
117 | ||
bdaff4a3 | 118 | /* |
4d25031a FY |
119 | * Two known BSP/CPU0 dependencies: Resume from suspend/hibernate |
120 | * depends on BSP. PIC interrupts depend on BSP. | |
fd6d7d26 | 121 | * |
4d25031a FY |
122 | * If the BSP depencies are under control, one can tell kernel to |
123 | * enable BSP hotplug. This basically adds a control file and | |
124 | * one can attempt to offline BSP. | |
bdaff4a3 | 125 | */ |
4d25031a FY |
126 | if (num == 0 && cpu0_hotpluggable) { |
127 | unsigned int irq; | |
128 | /* | |
129 | * We won't take down the boot processor on i386 if some | |
130 | * interrupts only are able to be serviced by the BSP in PIC. | |
131 | */ | |
132 | for_each_active_irq(irq) { | |
133 | if (!IO_APIC_IRQ(irq) && irq_has_action(irq)) { | |
134 | cpu0_hotpluggable = 0; | |
135 | break; | |
136 | } | |
137 | } | |
138 | } | |
139 | if (num || cpu0_hotpluggable) | |
30964d54 | 140 | per_cpu(cpu_devices, num).cpu.hotpluggable = 1; |
271eb5c5 | 141 | |
30964d54 | 142 | return register_cpu(&per_cpu(cpu_devices, num).cpu, num); |
1da177e4 | 143 | } |
3eaf5efa | 144 | EXPORT_SYMBOL(arch_register_cpu); |
1da177e4 | 145 | |
da54becc AM |
146 | void arch_unregister_cpu(int num) |
147 | { | |
9583d050 | 148 | unregister_cpu(&per_cpu(cpu_devices, num).cpu); |
1da177e4 | 149 | } |
1da177e4 | 150 | EXPORT_SYMBOL(arch_unregister_cpu); |
271eb5c5 JSR |
151 | #else /* CONFIG_HOTPLUG_CPU */ |
152 | ||
d9874026 | 153 | static int __init arch_register_cpu(int num) |
3eaf5efa SR |
154 | { |
155 | return register_cpu(&per_cpu(cpu_devices, num).cpu, num); | |
156 | } | |
271eb5c5 | 157 | #endif /* CONFIG_HOTPLUG_CPU */ |
1da177e4 | 158 | |
1da177e4 LT |
159 | static int __init topology_init(void) |
160 | { | |
161 | int i; | |
162 | ||
aada06c9 | 163 | #ifdef CONFIG_NUMA |
76e4f660 | 164 | for_each_online_node(i) |
0fc44159 | 165 | register_one_node(i); |
271eb5c5 | 166 | #endif |
76e4f660 | 167 | |
a888cebe | 168 | for_each_present_cpu(i) |
76e4f660 | 169 | arch_register_cpu(i); |
271eb5c5 | 170 | |
1da177e4 LT |
171 | return 0; |
172 | } | |
1da177e4 | 173 | subsys_initcall(topology_init); |