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Commit 29bd7fbc authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Thomas Gleixner
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x86/microcode: Convert to hotplug state machine 



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: default avatarSebastian 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: default avatarThomas Gleixner <tglx@linutronix.de>
parent 51533233

arch/x86/kernel/cpu/microcode/core.c

+17 −35
Original line number Diff line number Diff line
@@ -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);



	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.

		 */



	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;

	return 0;

}



	case CPU_DOWN_PREPARE:

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);

		break;



	/*

	 * 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.

	 */

	return 0;

}



	/* The CPU refused to come up during a system resume */

	if (action == CPU_UP_CANCELED_FROZEN)

		microcode_fini_cpu(cpu);



	return NOTIFY_OK;

}



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");