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x86/microcode: Convert to hotplug state machine

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Install the callbacks via the state machine. 
CPU_UP_CANCELED_FROZEN() is not preserved: It is only there to free memory in an
error case because it is assumed if the CPU does show up on resume it won't be
seen ever again. As per Borislav:
|IOW, you don't need mc_cpu_dead().

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160907164523.46a2xnffha4bv63g@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Sebastian Andrzej Siewior 2016-09-07 18:45:23 +02:00 committed by Thomas Gleixner
parent 515332336b
commit 29bd7fbc07
1 changed files with 17 additions and 35 deletions
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52
arch/x86/kernel/cpu/microcode/core.c
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@ -558,55 +558,36 @@ static struct syscore_ops mc_syscore_ops = {
.resume = mc_bp_resume,
};
static int
mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
static int mc_cpu_online(unsigned int cpu)
{
unsigned int cpu = (unsigned long)hcpu;
struct device *dev;
dev = get_cpu_device(cpu);
microcode_update_cpu(cpu);
pr_debug("CPU%d added\n", cpu);
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_ONLINE:
microcode_update_cpu(cpu);
pr_debug("CPU%d added\n", cpu);
/*
* "break" is missing on purpose here because we want to fall
* through in order to create the sysfs group.
*/
if (sysfs_create_group(&dev->kobj, &mc_attr_group))
pr_err("Failed to create group for CPU%d\n", cpu);
return 0;
}
case CPU_DOWN_FAILED:
if (sysfs_create_group(&dev->kobj, &mc_attr_group))
pr_err("Failed to create group for CPU%d\n", cpu);
break;
case CPU_DOWN_PREPARE:
/* Suspend is in progress, only remove the interface */
sysfs_remove_group(&dev->kobj, &mc_attr_group);
pr_debug("CPU%d removed\n", cpu);
break;
static int mc_cpu_down_prep(unsigned int cpu)
{
struct device *dev;
dev = get_cpu_device(cpu);
/* Suspend is in progress, only remove the interface */
sysfs_remove_group(&dev->kobj, &mc_attr_group);
pr_debug("CPU%d removed\n", cpu);
/*
* case CPU_DEAD:
*
* When a CPU goes offline, don't free up or invalidate the copy of
* the microcode in kernel memory, so that we can reuse it when the
* CPU comes back online without unnecessarily requesting the userspace
* for it again.
*/
}
/* The CPU refused to come up during a system resume */
if (action == CPU_UP_CANCELED_FROZEN)
microcode_fini_cpu(cpu);
return NOTIFY_OK;
return 0;
}
static struct notifier_block mc_cpu_notifier = {
.notifier_call = mc_cpu_callback,
};
static struct attribute *cpu_root_microcode_attrs[] = {
&dev_attr_reload.attr,
NULL
@ -665,7 +646,8 @@ int __init microcode_init(void)
goto out_ucode_group;
register_syscore_ops(&mc_syscore_ops);
register_hotcpu_notifier(&mc_cpu_notifier);
cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/microcode:online",
mc_cpu_online, mc_cpu_down_prep);
pr_info("Microcode Update Driver: v" MICROCODE_VERSION
" <tigran@aivazian.fsnet.co.uk>, Peter Oruba\n");