]>
Commit | Line | Data |
---|---|---|
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 | */ | |
a313357e | 28 | #include <linux/interrupt.h> |
1da177e4 | 29 | #include <linux/nodemask.h> |
69c60c88 | 30 | #include <linux/export.h> |
aada06c9 | 31 | #include <linux/mmzone.h> |
271eb5c5 JSR |
32 | #include <linux/init.h> |
33 | #include <linux/smp.h> | |
4d25031a | 34 | #include <linux/irq.h> |
13c01139 | 35 | #include <asm/io_apic.h> |
1da177e4 LT |
36 | #include <asm/cpu.h> |
37 | ||
30964d54 | 38 | static DEFINE_PER_CPU(struct x86_cpu, cpu_devices); |
1da177e4 | 39 | |
3eaf5efa | 40 | #ifdef CONFIG_HOTPLUG_CPU |
4d25031a FY |
41 | |
42 | #ifdef CONFIG_BOOTPARAM_HOTPLUG_CPU0 | |
43 | static int cpu0_hotpluggable = 1; | |
44 | #else | |
45 | static int cpu0_hotpluggable; | |
46 | static int __init enable_cpu0_hotplug(char *str) | |
47 | { | |
48 | cpu0_hotpluggable = 1; | |
49 | return 1; | |
50 | } | |
51 | ||
52 | __setup("cpu0_hotplug", enable_cpu0_hotplug); | |
53 | #endif | |
54 | ||
a71c8bc5 FY |
55 | #ifdef CONFIG_DEBUG_HOTPLUG_CPU0 |
56 | /* | |
57 | * This function offlines a CPU as early as possible and allows userspace to | |
58 | * boot up without the CPU. The CPU can be onlined back by user after boot. | |
59 | * | |
60 | * This is only called for debugging CPU offline/online feature. | |
61 | */ | |
4daa832d | 62 | int _debug_hotplug_cpu(int cpu, int action) |
a71c8bc5 | 63 | { |
a71c8bc5 FY |
64 | int ret; |
65 | ||
66 | if (!cpu_is_hotpluggable(cpu)) | |
67 | return -EINVAL; | |
68 | ||
a71c8bc5 FY |
69 | switch (action) { |
70 | case 0: | |
af7aa046 QY |
71 | ret = remove_cpu(cpu); |
72 | if (!ret) | |
8fea0f59 | 73 | pr_info("DEBUG_HOTPLUG_CPU0: CPU %u is now offline\n", cpu); |
af7aa046 | 74 | else |
a71c8bc5 FY |
75 | pr_debug("Can't offline CPU%d.\n", cpu); |
76 | break; | |
77 | case 1: | |
af7aa046 QY |
78 | ret = add_cpu(cpu); |
79 | if (ret) | |
a71c8bc5 | 80 | pr_debug("Can't online CPU%d.\n", cpu); |
af7aa046 | 81 | |
a71c8bc5 FY |
82 | break; |
83 | default: | |
84 | ret = -EINVAL; | |
85 | } | |
86 | ||
a71c8bc5 FY |
87 | return ret; |
88 | } | |
89 | ||
90 | static int __init debug_hotplug_cpu(void) | |
91 | { | |
92 | _debug_hotplug_cpu(0, 0); | |
93 | return 0; | |
94 | } | |
95 | ||
96 | late_initcall_sync(debug_hotplug_cpu); | |
97 | #endif /* CONFIG_DEBUG_HOTPLUG_CPU0 */ | |
98 | ||
4daa832d | 99 | int arch_register_cpu(int num) |
76b67ed9 | 100 | { |
4d25031a FY |
101 | struct cpuinfo_x86 *c = &cpu_data(num); |
102 | ||
103 | /* | |
104 | * Currently CPU0 is only hotpluggable on Intel platforms. Other | |
105 | * vendors can add hotplug support later. | |
99969675 | 106 | * Xen PV guests don't support CPU0 hotplug at all. |
4d25031a | 107 | */ |
99969675 JG |
108 | if (c->x86_vendor != X86_VENDOR_INTEL || |
109 | boot_cpu_has(X86_FEATURE_XENPV)) | |
4d25031a FY |
110 | cpu0_hotpluggable = 0; |
111 | ||
bdaff4a3 | 112 | /* |
4d25031a FY |
113 | * Two known BSP/CPU0 dependencies: Resume from suspend/hibernate |
114 | * depends on BSP. PIC interrupts depend on BSP. | |
fd6d7d26 | 115 | * |
d9f6e12f | 116 | * If the BSP dependencies are under control, one can tell kernel to |
4d25031a FY |
117 | * enable BSP hotplug. This basically adds a control file and |
118 | * one can attempt to offline BSP. | |
bdaff4a3 | 119 | */ |
4d25031a FY |
120 | if (num == 0 && cpu0_hotpluggable) { |
121 | unsigned int irq; | |
122 | /* | |
123 | * We won't take down the boot processor on i386 if some | |
124 | * interrupts only are able to be serviced by the BSP in PIC. | |
125 | */ | |
126 | for_each_active_irq(irq) { | |
127 | if (!IO_APIC_IRQ(irq) && irq_has_action(irq)) { | |
128 | cpu0_hotpluggable = 0; | |
129 | break; | |
130 | } | |
131 | } | |
132 | } | |
133 | if (num || cpu0_hotpluggable) | |
30964d54 | 134 | per_cpu(cpu_devices, num).cpu.hotpluggable = 1; |
271eb5c5 | 135 | |
30964d54 | 136 | return register_cpu(&per_cpu(cpu_devices, num).cpu, num); |
1da177e4 | 137 | } |
3eaf5efa | 138 | EXPORT_SYMBOL(arch_register_cpu); |
1da177e4 | 139 | |
da54becc AM |
140 | void arch_unregister_cpu(int num) |
141 | { | |
9583d050 | 142 | unregister_cpu(&per_cpu(cpu_devices, num).cpu); |
1da177e4 | 143 | } |
1da177e4 | 144 | EXPORT_SYMBOL(arch_unregister_cpu); |
271eb5c5 JSR |
145 | #else /* CONFIG_HOTPLUG_CPU */ |
146 | ||
d9874026 | 147 | static int __init arch_register_cpu(int num) |
3eaf5efa SR |
148 | { |
149 | return register_cpu(&per_cpu(cpu_devices, num).cpu, num); | |
150 | } | |
271eb5c5 | 151 | #endif /* CONFIG_HOTPLUG_CPU */ |
1da177e4 | 152 | |
1da177e4 LT |
153 | static int __init topology_init(void) |
154 | { | |
155 | int i; | |
156 | ||
aada06c9 | 157 | #ifdef CONFIG_NUMA |
76e4f660 | 158 | for_each_online_node(i) |
0fc44159 | 159 | register_one_node(i); |
271eb5c5 | 160 | #endif |
76e4f660 | 161 | |
a888cebe | 162 | for_each_present_cpu(i) |
76e4f660 | 163 | arch_register_cpu(i); |
271eb5c5 | 164 | |
1da177e4 LT |
165 | return 0; |
166 | } | |
1da177e4 | 167 | subsys_initcall(topology_init); |