[PATCH] x86: check for online cpus before bringing them up

[linux-2.6-omap-h63xx.git] / arch / i386 / kernel / smpboot.c

diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c
index 255adb498268bd0f27b0020fd4402682d0432a1a..7007e1783797a1997765a3100950b5b41c2ee4a1 100644 (file)
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -87,11 +87,7 @@ EXPORT_SYMBOL(cpu_online_map);
 cpumask_t cpu_callin_map;
 cpumask_t cpu_callout_map;
 EXPORT_SYMBOL(cpu_callout_map);
-#ifdef CONFIG_HOTPLUG_CPU
-cpumask_t cpu_possible_map = CPU_MASK_ALL;
-#else
 cpumask_t cpu_possible_map;
-#endif
 EXPORT_SYMBOL(cpu_possible_map);
 static cpumask_t smp_commenced_mask;
 
@@ -902,12 +898,6 @@ static int __devinit do_boot_cpu(int apicid, int cpu)
        unsigned long start_eip;
        unsigned short nmi_high = 0, nmi_low = 0;
 
-       if (!cpu_gdt_descr[cpu].address &&
-           !(cpu_gdt_descr[cpu].address = get_zeroed_page(GFP_KERNEL))) {
-               printk("Failed to allocate GDT for CPU %d\n", cpu);
-               return 1;
-       }
-
        ++cpucount;
 
        /*
@@ -1039,6 +1029,16 @@ int __devinit smp_prepare_cpu(int cpu)
        int     apicid, ret;
 
        lock_cpu_hotplug();
+
+       /*
+        * On x86, CPU0 is never offlined.  Trying to bring up an
+        * already-booted CPU will hang.  So check for that case.
+        */
+       if (cpu_online(cpu)) {
+               ret = -EINVAL;
+               goto exit;
+       }
+
        apicid = x86_cpu_to_apicid[cpu];
        if (apicid == BAD_APICID) {
                ret = -ENODEV;