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Diffstat (limited to 'arch/x86/kernel/topology.c')
-rw-r--r--arch/x86/kernel/topology.c123
1 files changed, 2 insertions, 121 deletions
diff --git a/arch/x86/kernel/topology.c b/arch/x86/kernel/topology.c
index 8617d1ed9d31..d42c28b8bfd8 100644
--- a/arch/x86/kernel/topology.c
+++ b/arch/x86/kernel/topology.c
@@ -35,128 +35,9 @@
#include <asm/io_apic.h>
#include <asm/cpu.h>
-static DEFINE_PER_CPU(struct x86_cpu, cpu_devices);
-
#ifdef CONFIG_HOTPLUG_CPU
-
-#ifdef CONFIG_BOOTPARAM_HOTPLUG_CPU0
-static int cpu0_hotpluggable = 1;
-#else
-static int cpu0_hotpluggable;
-static int __init enable_cpu0_hotplug(char *str)
-{
- cpu0_hotpluggable = 1;
- return 1;
-}
-
-__setup("cpu0_hotplug", enable_cpu0_hotplug);
-#endif
-
-#ifdef CONFIG_DEBUG_HOTPLUG_CPU0
-/*
- * This function offlines a CPU as early as possible and allows userspace to
- * boot up without the CPU. The CPU can be onlined back by user after boot.
- *
- * This is only called for debugging CPU offline/online feature.
- */
-int _debug_hotplug_cpu(int cpu, int action)
-{
- int ret;
-
- if (!cpu_is_hotpluggable(cpu))
- return -EINVAL;
-
- switch (action) {
- case 0:
- ret = remove_cpu(cpu);
- if (!ret)
- pr_info("DEBUG_HOTPLUG_CPU0: CPU %u is now offline\n", cpu);
- else
- pr_debug("Can't offline CPU%d.\n", cpu);
- break;
- case 1:
- ret = add_cpu(cpu);
- if (ret)
- pr_debug("Can't online CPU%d.\n", cpu);
-
- break;
- default:
- ret = -EINVAL;
- }
-
- return ret;
-}
-
-static int __init debug_hotplug_cpu(void)
-{
- _debug_hotplug_cpu(0, 0);
- return 0;
-}
-
-late_initcall_sync(debug_hotplug_cpu);
-#endif /* CONFIG_DEBUG_HOTPLUG_CPU0 */
-
-int arch_register_cpu(int num)
-{
- struct cpuinfo_x86 *c = &cpu_data(num);
-
- /*
- * Currently CPU0 is only hotpluggable on Intel platforms. Other
- * vendors can add hotplug support later.
- * Xen PV guests don't support CPU0 hotplug at all.
- */
- if (c->x86_vendor != X86_VENDOR_INTEL ||
- boot_cpu_has(X86_FEATURE_XENPV))
- cpu0_hotpluggable = 0;
-
- /*
- * Two known BSP/CPU0 dependencies: Resume from suspend/hibernate
- * depends on BSP. PIC interrupts depend on BSP.
- *
- * If the BSP dependencies are under control, one can tell kernel to
- * enable BSP hotplug. This basically adds a control file and
- * one can attempt to offline BSP.
- */
- if (num == 0 && cpu0_hotpluggable) {
- unsigned int irq;
- /*
- * We won't take down the boot processor on i386 if some
- * interrupts only are able to be serviced by the BSP in PIC.
- */
- for_each_active_irq(irq) {
- if (!IO_APIC_IRQ(irq) && irq_has_action(irq)) {
- cpu0_hotpluggable = 0;
- break;
- }
- }
- }
- if (num || cpu0_hotpluggable)
- per_cpu(cpu_devices, num).cpu.hotpluggable = 1;
-
- return register_cpu(&per_cpu(cpu_devices, num).cpu, num);
-}
-EXPORT_SYMBOL(arch_register_cpu);
-
-void arch_unregister_cpu(int num)
+bool arch_cpu_is_hotpluggable(int cpu)
{
- unregister_cpu(&per_cpu(cpu_devices, num).cpu);
-}
-EXPORT_SYMBOL(arch_unregister_cpu);
-#else /* CONFIG_HOTPLUG_CPU */
-
-static int __init arch_register_cpu(int num)
-{
- return register_cpu(&per_cpu(cpu_devices, num).cpu, num);
+ return cpu > 0;
}
#endif /* CONFIG_HOTPLUG_CPU */
-
-static int __init topology_init(void)
-{
- int i;
-
- for_each_present_cpu(i)
- arch_register_cpu(i);
-
- return 0;
-}
-subsys_initcall(topology_init);