cpu/hotplug: Add sysfs state interface (98f8cdce) · Commits · 戴 / test

kernel/cpu.c

+100 −0

Original line number	Diff line number	Diff line
		@@ -56,6 +56,7 @@ struct cpuhp_step {
		bool skip_onerr;
		};

		static DEFINE_MUTEX(cpuhp_state_mutex);
		static struct cpuhp_step cpuhp_bp_states[];
		static struct cpuhp_step cpuhp_ap_states[];

		@@ -955,6 +956,105 @@ static struct cpuhp_step cpuhp_ap_states[] = {
		},
		};

		static bool cpuhp_is_ap_state(enum cpuhp_state state)
		{
		return (state > CPUHP_AP_OFFLINE && state < CPUHP_AP_ONLINE);
		}

		static struct cpuhp_step *cpuhp_get_step(enum cpuhp_state state)
		{
		struct cpuhp_step *sp;

		sp = cpuhp_is_ap_state(state) ? cpuhp_ap_states : cpuhp_bp_states;
		return sp + state;
		}

		#if defined(CONFIG_SYSFS) && defined(CONFIG_HOTPLUG_CPU)
		static ssize_t show_cpuhp_state(struct device *dev,
		struct device_attribute attr, char buf)
		{
		struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id);

		return sprintf(buf, "%d\n", st->state);
		}
		static DEVICE_ATTR(state, 0444, show_cpuhp_state, NULL);

		static ssize_t show_cpuhp_target(struct device *dev,
		struct device_attribute attr, char buf)
		{
		struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id);

		return sprintf(buf, "%d\n", st->target);
		}
		static DEVICE_ATTR(target, 0444, show_cpuhp_target, NULL);

		static struct attribute *cpuhp_cpu_attrs[] = {
		&dev_attr_state.attr,
		&dev_attr_target.attr,
		NULL
		};

		static struct attribute_group cpuhp_cpu_attr_group = {
		.attrs = cpuhp_cpu_attrs,
		.name = "hotplug",
		NULL
		};

		static ssize_t show_cpuhp_states(struct device *dev,
		struct device_attribute attr, char buf)
		{
		ssize_t cur, res = 0;
		int i;

		mutex_lock(&cpuhp_state_mutex);
		for (i = 0; i <= CPUHP_ONLINE; i++) {
		struct cpuhp_step *sp = cpuhp_get_step(i);

		if (sp->name) {
		cur = sprintf(buf, "%3d: %s\n", i, sp->name);
		buf += cur;
		res += cur;
		}
		}
		mutex_unlock(&cpuhp_state_mutex);
		return res;
		}
		static DEVICE_ATTR(states, 0444, show_cpuhp_states, NULL);

		static struct attribute *cpuhp_cpu_root_attrs[] = {
		&dev_attr_states.attr,
		NULL
		};

		static struct attribute_group cpuhp_cpu_root_attr_group = {
		.attrs = cpuhp_cpu_root_attrs,
		.name = "hotplug",
		NULL
		};

		static int __init cpuhp_sysfs_init(void)
		{
		int cpu, ret;

		ret = sysfs_create_group(&cpu_subsys.dev_root->kobj,
		&cpuhp_cpu_root_attr_group);
		if (ret)
		return ret;

		for_each_possible_cpu(cpu) {
		struct device *dev = get_cpu_device(cpu);

		if (!dev)
		continue;
		ret = sysfs_create_group(&dev->kobj, &cpuhp_cpu_attr_group);
		if (ret)
		return ret;
		}
		return 0;
		}
		device_initcall(cpuhp_sysfs_init);
		#endif

		/*
		* cpu_bit_bitmap[] is a special, "compressed" data structure that
		* represents all NR_CPUS bits binary values of 1<<nr.

Admin message