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s390/smp: Convert to hotplug state machine

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cpuhp_setup_state() invokes the startup callback on all online cpus with
the proper protection, so we can remove the cpu hotplug protection from the
init function and the creation of the per cpu files for online cpus in
smp_add_present_cpu(). smp_add_present_cpu() is called also called from
__smp_rescan_cpus(), but this callpath never adds an online cpu, it merily
adds newly present cpus, so the creation of the cpu files is not required.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20161104144502.7kd4bxz2rxqvtack@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Sebastian Andrzej Siewior 2016-11-04 15:45:03 +01:00 committed by Thomas Gleixner
parent ef65d45cbf
commit dfbbd86a0f
1 changed files with 11 additions and 26 deletions
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37
arch/s390/kernel/smp.c
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@ -1047,23 +1047,18 @@ static struct attribute_group cpu_online_attr_group = {
.attrs = cpu_online_attrs,
};
static int smp_cpu_notify(struct notifier_block *self, unsigned long action,
void *hcpu)
static int smp_cpu_online(unsigned int cpu)
{
unsigned int cpu = (unsigned int)(long)hcpu;
struct device *s = &per_cpu(cpu_device, cpu)->dev;
int err = 0;
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_ONLINE:
case CPU_DOWN_FAILED:
err = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
break;
case CPU_DOWN_PREPARE:
sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
break;
}
return notifier_from_errno(err);
return sysfs_create_group(&s->kobj, &cpu_online_attr_group);
}
static int smp_cpu_pre_down(unsigned int cpu)
{
struct device *s = &per_cpu(cpu_device, cpu)->dev;
sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
return 0;
}
static int smp_add_present_cpu(int cpu)
@ -1084,20 +1079,12 @@ static int smp_add_present_cpu(int cpu)
rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
if (rc)
goto out_cpu;
if (cpu_online(cpu)) {
rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
if (rc)
goto out_online;
}
rc = topology_cpu_init(c);
if (rc)
goto out_topology;
return 0;
out_topology:
if (cpu_online(cpu))
sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
out_online:
sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
out_cpu:
#ifdef CONFIG_HOTPLUG_CPU
@ -1150,17 +1137,15 @@ static int __init s390_smp_init(void)
if (rc)
return rc;
#endif
cpu_notifier_register_begin();
for_each_present_cpu(cpu) {
rc = smp_add_present_cpu(cpu);
if (rc)
goto out;
}
__hotcpu_notifier(smp_cpu_notify, 0);
rc = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "s390/smp:online",
smp_cpu_online, smp_cpu_pre_down);
out:
cpu_notifier_register_done();
return rc;
}
subsys_initcall(s390_smp_init);