[PATCH] Check if cpu can be onlined before calling smp_prepare_cpu()

[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 4c470e99a74202d4afd857e0797dfdfd7ab687a5..82371d83bfa912719c57971980c103b28504cea2 100644 (file)
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -1003,7 +1003,6 @@ void cpu_exit_clear(void)
 
        cpu_clear(cpu, cpu_callout_map);
        cpu_clear(cpu, cpu_callin_map);
-       cpu_clear(cpu, cpu_present_map);
 
        cpu_clear(cpu, smp_commenced_mask);
        unmap_cpu_to_logical_apicid(cpu);
@@ -1015,31 +1014,20 @@ struct warm_boot_cpu_info {
        int cpu;
 };
 
-static void __devinit do_warm_boot_cpu(void *p)
+static void __cpuinit do_warm_boot_cpu(void *p)
 {
        struct warm_boot_cpu_info *info = p;
        do_boot_cpu(info->apicid, info->cpu);
        complete(info->complete);
 }
 
-int __devinit smp_prepare_cpu(int cpu)
+static int __cpuinit __smp_prepare_cpu(int cpu)
 {
        DECLARE_COMPLETION(done);
        struct warm_boot_cpu_info info;
        struct work_struct task;
        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;
@@ -1064,7 +1052,6 @@ int __devinit smp_prepare_cpu(int cpu)
        zap_low_mappings();
        ret = 0;
 exit:
-       unlock_cpu_hotplug();
        return ret;
 }
 #endif
@@ -1392,6 +1379,22 @@ void __cpu_die(unsigned int cpu)
 
 int __devinit __cpu_up(unsigned int cpu)
 {
+#ifdef CONFIG_HOTPLUG_CPU
+       int ret=0;
+
+       /*
+        * We do warm boot only on cpus that had booted earlier
+        * Otherwise cold boot is all handled from smp_boot_cpus().
+        * cpu_callin_map is set during AP kickstart process. Its reset
+        * when a cpu is taken offline from cpu_exit_clear().
+        */
+       if (!cpu_isset(cpu, cpu_callin_map))
+               ret = __smp_prepare_cpu(cpu);
+
+       if (ret)
+               return -EIO;
+#endif
+
        /* In case one didn't come up */
        if (!cpu_isset(cpu, cpu_callin_map)) {
                printk(KERN_DEBUG "skipping cpu%d, didn't come online\n", cpu);