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Commit 5e0925de authored by Olav Haugan's avatar Olav Haugan Committed by Satya Durga Srinivasu Prabhala
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drivers/base: cpu: Add node for cpu isolation 



Add a new per-cpu node to control isolation of CPU.

Usage:
echo 1 > isolate - Isolate the core
echo 0 > isolate - Unisolate the core

Change-Id: I11385d8072f8fa6e69b58588bf6996a16ebf3d35
Signed-off-by: default avatarOlav Haugan <ohaugan@codeaurora.org>
[markivx: Adjust for lack of HMP]
Signed-off-by: default avatarVikram Mulukutla <markivx@codeaurora.org>
Signed-off-by: default avatarSatya Durga Srinivasu Prabhala <satyap@codeaurora.org>
parent f191c4a4

drivers/base/cpu.c

+58 −0
Original line number Diff line number Diff line
@@ -183,9 +183,64 @@ static struct attribute_group crash_note_cpu_attr_group = { 
};

#endif



#ifdef CONFIG_HOTPLUG_CPU



static ssize_t show_cpu_isolated(struct device *dev,

				struct device_attribute *attr, char *buf)

{

	struct cpu *cpu = container_of(dev, struct cpu, dev);

	ssize_t rc;

	int cpuid = cpu->dev.id;

	unsigned int isolated = cpu_isolated(cpuid);



	rc = snprintf(buf, PAGE_SIZE-2, "%d\n", isolated);



	return rc;

}



static ssize_t __ref store_cpu_isolated(struct device *dev,

				struct device_attribute *attr,

				const char *buf, size_t count)

{

	struct cpu *cpu = container_of(dev, struct cpu, dev);

	int err;

	int cpuid = cpu->dev.id;

	unsigned int isolated;



	err = kstrtouint(strstrip((char *)buf), 0, &isolated);

	if (err)

		return err;



	if (isolated > 1)

		return -EINVAL;



	if (isolated)

		sched_isolate_cpu(cpuid);

	else

		sched_unisolate_cpu(cpuid);



	return count;

}



static DEVICE_ATTR(isolate, 0644, show_cpu_isolated, store_cpu_isolated);



static struct attribute *cpu_isolated_attrs[] = {

	&dev_attr_isolate.attr,

	NULL

};



static struct attribute_group cpu_isolated_attr_group = {

	.attrs = cpu_isolated_attrs,

};



#endif



static const struct attribute_group *common_cpu_attr_groups[] = {

#ifdef CONFIG_KEXEC

	&crash_note_cpu_attr_group,

#endif

#ifdef CONFIG_HOTPLUG_CPU

	&cpu_isolated_attr_group,

#endif

	NULL

};
@@ -193,6 +248,9 @@ static const struct attribute_group *common_cpu_attr_groups[] = { 
static const struct attribute_group *hotplugable_cpu_attr_groups[] = {

#ifdef CONFIG_KEXEC

	&crash_note_cpu_attr_group,

#endif

#ifdef CONFIG_HOTPLUG_CPU

	&cpu_isolated_attr_group,

#endif

	NULL

};