1 files changed, 85 insertions, 0 deletions

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 644e60969f90..c35cd319d1ed 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -2,6 +2,13 @@
 #include <linux/smp.h>
 #include <linux/module.h>
 #include <linux/sched.h>
+#include <linux/percpu.h>
+
+#include <asm/nmi.h>
+#include <asm/irq.h>
+#include <asm/smp.h>
+#include <asm/cpu.h>
+#include <asm/numa.h>
 
 /* Number of siblings per CPU package */
 int smp_num_siblings = 1;
@@ -181,5 +188,83 @@ __init void prefill_possible_map(void)
         for (i = 0; i < possible; i++)
                 cpu_set(i, cpu_possible_map);
 }
+
+static void __ref remove_cpu_from_maps(int cpu)
+{
+        cpu_clear(cpu, cpu_online_map);
+#ifdef CONFIG_X86_64
+        cpu_clear(cpu, cpu_callout_map);
+        cpu_clear(cpu, cpu_callin_map);
+        /* was set by cpu_init() */
+        clear_bit(cpu, (unsigned long *)&cpu_initialized);
+        clear_node_cpumask(cpu);
+#endif
+}
+
+int __cpu_disable(void)
+{
+        int cpu = smp_processor_id();
+
+        /*
+         * Perhaps use cpufreq to drop frequency, but that could go
+         * into generic code.
+         *
+         * We won't take down the boot processor on i386 due to some
+         * interrupts only being able to be serviced by the BSP.
+         * Especially so if we're not using an IOAPIC   -zwane
+         */
+        if (cpu == 0)
+                return -EBUSY;
+
+        if (nmi_watchdog == NMI_LOCAL_APIC)
+                stop_apic_nmi_watchdog(NULL);
+        clear_local_APIC();
+
+        /*
+         * HACK:
+         * Allow any queued timer interrupts to get serviced
+         * This is only a temporary solution until we cleanup
+         * fixup_irqs as we do for IA64.
+         */
+        local_irq_enable();
+        mdelay(1);
+
+        local_irq_disable();
+        remove_siblinginfo(cpu);
+
+        /* It's now safe to remove this processor from the online map */
+        remove_cpu_from_maps(cpu);
+        fixup_irqs(cpu_online_map);
+        return 0;
+}
+
+void __cpu_die(unsigned int cpu)
+{
+        /* We don't do anything here: idle task is faking death itself. */
+        unsigned int i;
+
+        for (i = 0; i < 10; i++) {
+                /* They ack this in play_dead by setting CPU_DEAD */
+                if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
+                        printk(KERN_INFO "CPU %d is now offline\n", cpu);
+                        if (1 == num_online_cpus())
+                                alternatives_smp_switch(0);
+                        return;
+                }
+                msleep(100);
+        }
+        printk(KERN_ERR "CPU %u didn't die...\n", cpu);
+}
+#else /* ... !CONFIG_HOTPLUG_CPU */
+int __cpu_disable(void)
+{
+        return -ENOSYS;
+}
+
+void __cpu_die(unsigned int cpu)
+{
+        /* We said "no" in __cpu_disable */
+        BUG();
+}
 #endif