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authorAshok Raj <ashok.raj@intel.com>2006-03-25 03:08:18 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-25 08:23:01 -0800
commit34f361ade2fb4a869f6a7714d01c04ce4cfa75d9 (patch)
treea250999fc386ddbfe3c92e4d8ffdcf2d3393134a
parentf1a1c2dc2a956c375b432d2a9a28e52ba9d81c7c (diff)
[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>
-rw-r--r--arch/i386/kernel/smpboot.c33
-rw-r--r--drivers/base/cpu.c9
-rw-r--r--include/linux/cpu.h1
-rw-r--r--kernel/power/smp.c4
4 files changed, 20 insertions, 27 deletions
diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c
index 4c470e99a74..82371d83bfa 100644
--- 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);
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 29f3d7504da..dd712b24ec9 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -19,11 +19,6 @@ EXPORT_SYMBOL(cpu_sysdev_class);
static struct sys_device *cpu_sys_devices[NR_CPUS];
#ifdef CONFIG_HOTPLUG_CPU
-int __attribute__((weak)) smp_prepare_cpu (int cpu)
-{
- return 0;
-}
-
static ssize_t show_online(struct sys_device *dev, char *buf)
{
struct cpu *cpu = container_of(dev, struct cpu, sysdev);
@@ -44,9 +39,7 @@ static ssize_t store_online(struct sys_device *dev, const char *buf,
kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
break;
case '1':
- ret = smp_prepare_cpu(cpu->sysdev.id);
- if (!ret)
- ret = cpu_up(cpu->sysdev.id);
+ ret = cpu_up(cpu->sysdev.id);
if (!ret)
kobject_uevent(&dev->kobj, KOBJ_ONLINE);
break;
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index d612b89dce3..08d50c53aab 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -74,7 +74,6 @@ extern int lock_cpu_hotplug_interruptible(void);
register_cpu_notifier(&fn##_nb); \
}
int cpu_down(unsigned int cpu);
-extern int __attribute__((weak)) smp_prepare_cpu(int cpu);
#define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
#else
#define lock_cpu_hotplug() do { } while (0)
diff --git a/kernel/power/smp.c b/kernel/power/smp.c
index 911fc62b822..5957312b2d6 100644
--- a/kernel/power/smp.c
+++ b/kernel/power/smp.c
@@ -49,9 +49,7 @@ void enable_nonboot_cpus(void)
printk("Thawing cpus ...\n");
for_each_cpu_mask(cpu, frozen_cpus) {
- error = smp_prepare_cpu(cpu);
- if (!error)
- error = cpu_up(cpu);
+ error = cpu_up(cpu);
if (!error) {
printk("CPU%d is up\n", cpu);
continue;