[PATCH] Check if cpu can be onlined before calling smp_prepare_cpu()
- Moved check for online cpu out of smp_prepare_cpu()
- Moved default declaration of smp_prepare_cpu() to kernel/cpu.c
- Removed lock_cpu_hotplug() from smp_prepare_cpu() to around it, since
its called from cpu_up() as well now.
- Removed clearing from cpu_present_map during cpu_offline as it breaks
using cpu_up() directly during a subsequent online operation.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: "Li, Shaohua" <shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c
index 4c470e9..82371d8 100644
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -1003,7 +1003,6 @@
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 @@
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 @@
zap_low_mappings();
ret = 0;
exit:
- unlock_cpu_hotplug();
return ret;
}
#endif
@@ -1392,6 +1379,22 @@
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);