[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 d16520da4550e6d1b5d318a56a2f1ba1b852728c..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;
 
@@ -875,8 +871,7 @@ static inline struct task_struct * alloc_idle_task(int cpu)
                /* initialize thread_struct.  we really want to avoid destroy
                 * idle tread
                 */
-               idle->thread.esp = (unsigned long)(((struct pt_regs *)
-                       (THREAD_SIZE + (unsigned long) idle->thread_info)) - 1);
+               idle->thread.esp = (unsigned long)task_pt_regs(idle);
                init_idle(idle, cpu);
                return idle;
        }
@@ -1034,6 +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;
@@ -1090,6 +1095,7 @@ static void smp_tune_scheduling (void)
                        cachesize = 16; /* Pentiums, 2x8kB cache */
                        bandwidth = 100;
                }
+               max_cache_size = cachesize * 1024;
        }
 }
 
@@ -1338,8 +1344,7 @@ int __cpu_disable(void)
        if (cpu == 0)
                return -EBUSY;
 
-       /* We enable the timer again on the exit path of the death loop */
-       disable_APIC_timer();
+       clear_local_APIC();
        /* Allow any queued timer interrupts to get serviced */
        local_irq_enable();
        mdelay(1);