[mirror_ubuntu-zesty-kernel.git] / drivers / base / cpu.c

/*
 * drivers/base/cpu.c - basic CPU class support
 */

#include <linux/sysdev.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/cpu.h>
#include <linux/topology.h>
#include <linux/device.h>
#include <linux/node.h>

#include "base.h"

struct sysdev_class cpu_sysdev_class = {
	.name = "cpu",
};
EXPORT_SYMBOL(cpu_sysdev_class);

static DEFINE_PER_CPU(struct sys_device *, cpu_sys_devices);

#ifdef CONFIG_HOTPLUG_CPU
static ssize_t show_online(struct sys_device *dev, struct sysdev_attribute *attr,
			   char *buf)
{
	struct cpu *cpu = container_of(dev, struct cpu, sysdev);

	return sprintf(buf, "%u\n", !!cpu_online(cpu->sysdev.id));
}

static ssize_t __ref store_online(struct sys_device *dev, struct sysdev_attribute *attr,
				 const char *buf, size_t count)
{
	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
	ssize_t ret;

	switch (buf[0]) {
	case '0':
		ret = cpu_down(cpu->sysdev.id);
		if (!ret)
			kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
		break;
	case '1':
		ret = cpu_up(cpu->sysdev.id);
		if (!ret)
			kobject_uevent(&dev->kobj, KOBJ_ONLINE);
		break;
	default:
		ret = -EINVAL;
	}

	if (ret >= 0)
		ret = count;
	return ret;
}
static SYSDEV_ATTR(online, 0644, show_online, store_online);

static void __cpuinit register_cpu_control(struct cpu *cpu)
{
	sysdev_create_file(&cpu->sysdev, &attr_online);
}
void unregister_cpu(struct cpu *cpu)
{
	int logical_cpu = cpu->sysdev.id;

	unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));

	sysdev_remove_file(&cpu->sysdev, &attr_online);

	sysdev_unregister(&cpu->sysdev);
	per_cpu(cpu_sys_devices, logical_cpu) = NULL;
	return;
}

#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
static ssize_t cpu_probe_store(struct class *class, const char *buf,
			       size_t count)
{
	return arch_cpu_probe(buf, count);
}

static ssize_t cpu_release_store(struct class *class, const char *buf,
				 size_t count)
{
	return arch_cpu_release(buf, count);
}

static CLASS_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
static CLASS_ATTR(release, S_IWUSR, NULL, cpu_release_store);

int __init cpu_probe_release_init(void)
{
	int rc;

	rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
			       &class_attr_probe.attr);
	if (!rc)
		rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
				       &class_attr_release.attr);

	return rc;
}
device_initcall(cpu_probe_release_init);
#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */

#else /* ... !CONFIG_HOTPLUG_CPU */
static inline void register_cpu_control(struct cpu *cpu)
{
}
#endif /* CONFIG_HOTPLUG_CPU */

#ifdef CONFIG_KEXEC
#include <linux/kexec.h>

static ssize_t show_crash_notes(struct sys_device *dev, struct sysdev_attribute *attr,
				char *buf)
{
	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
	ssize_t rc;
	unsigned long long addr;
	int cpunum;

	cpunum = cpu->sysdev.id;

	/*
	 * Might be reading other cpu's data based on which cpu read thread
	 * has been scheduled. But cpu data (memory) is allocated once during
	 * boot up and this data does not change there after. Hence this
	 * operation should be safe. No locking required.
	 */
	addr = __pa(per_cpu_ptr(crash_notes, cpunum));
	rc = sprintf(buf, "%Lx\n", addr);
	return rc;
}
static SYSDEV_ATTR(crash_notes, 0400, show_crash_notes, NULL);
#endif

/*
 * Print cpu online, possible, present, and system maps
 */
static ssize_t print_cpus_map(char *buf, const struct cpumask *map)
{
	int n = cpulist_scnprintf(buf, PAGE_SIZE-2, map);

	buf[n++] = '\n';
	buf[n] = '\0';
	return n;
}

#define	print_cpus_func(type) \
static ssize_t print_cpus_##type(struct sysdev_class *class, char *buf)	\
{									\
	return print_cpus_map(buf, cpu_##type##_mask);			\
}									\
static struct sysdev_class_attribute attr_##type##_map = 		\
	_SYSDEV_CLASS_ATTR(type, 0444, print_cpus_##type, NULL)

print_cpus_func(online);
print_cpus_func(possible);
print_cpus_func(present);

/*
 * Print values for NR_CPUS and offlined cpus
 */
static ssize_t print_cpus_kernel_max(struct sysdev_class *class, char *buf)
{
	int n = snprintf(buf, PAGE_SIZE-2, "%d\n", NR_CPUS - 1);
	return n;
}
static SYSDEV_CLASS_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL);

/* arch-optional setting to enable display of offline cpus >= nr_cpu_ids */
unsigned int total_cpus;

static ssize_t print_cpus_offline(struct sysdev_class *class, char *buf)
{
	int n = 0, len = PAGE_SIZE-2;
	cpumask_var_t offline;

	/* display offline cpus < nr_cpu_ids */
	if (!alloc_cpumask_var(&offline, GFP_KERNEL))
		return -ENOMEM;
	cpumask_complement(offline, cpu_online_mask);
	n = cpulist_scnprintf(buf, len, offline);
	free_cpumask_var(offline);

	/* display offline cpus >= nr_cpu_ids */
	if (total_cpus && nr_cpu_ids < total_cpus) {
		if (n && n < len)
			buf[n++] = ',';

		if (nr_cpu_ids == total_cpus-1)
			n += snprintf(&buf[n], len - n, "%d", nr_cpu_ids);
		else
			n += snprintf(&buf[n], len - n, "%d-%d",
						      nr_cpu_ids, total_cpus-1);
	}

	n += snprintf(&buf[n], len - n, "\n");
	return n;
}
static SYSDEV_CLASS_ATTR(offline, 0444, print_cpus_offline, NULL);

static struct sysdev_class_attribute *cpu_state_attr[] = {
	&attr_online_map,
	&attr_possible_map,
	&attr_present_map,
	&attr_kernel_max,
	&attr_offline,
};

static int cpu_states_init(void)
{
	int i;
	int err = 0;

	for (i = 0;  i < ARRAY_SIZE(cpu_state_attr); i++) {
		int ret;
		ret = sysdev_class_create_file(&cpu_sysdev_class,
						cpu_state_attr[i]);
		if (!err)
			err = ret;
	}
	return err;
}

/*
 * register_cpu - Setup a sysfs device for a CPU.
 * @cpu - cpu->hotpluggable field set to 1 will generate a control file in
 *	  sysfs for this CPU.
 * @num - CPU number to use when creating the device.
 *
 * Initialize and register the CPU device.
 */
int __cpuinit register_cpu(struct cpu *cpu, int num)
{
	int error;
	cpu->node_id = cpu_to_node(num);
	cpu->sysdev.id = num;
	cpu->sysdev.cls = &cpu_sysdev_class;

	error = sysdev_register(&cpu->sysdev);

	if (!error && cpu->hotpluggable)
		register_cpu_control(cpu);
	if (!error)
		per_cpu(cpu_sys_devices, num) = &cpu->sysdev;
	if (!error)
		register_cpu_under_node(num, cpu_to_node(num));

#ifdef CONFIG_KEXEC
	if (!error)
		error = sysdev_create_file(&cpu->sysdev, &attr_crash_notes);
#endif
	return error;
}

struct sys_device *get_cpu_sysdev(unsigned cpu)
{
	if (cpu < nr_cpu_ids && cpu_possible(cpu))
		return per_cpu(cpu_sys_devices, cpu);
	else
		return NULL;
}
EXPORT_SYMBOL_GPL(get_cpu_sysdev);

int __init cpu_dev_init(void)
{
	int err;

	err = sysdev_class_register(&cpu_sysdev_class);
	if (!err)
		err = cpu_states_init();

#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
	if (!err)
		err = sched_create_sysfs_power_savings_entries(&cpu_sysdev_class);
#endif

	return err;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* drivers/base/cpu.c - basic CPU class support
	3	*/
	4
	5	#include <linux/sysdev.h>
	6	#include <linux/module.h>
	7	#include <linux/init.h>
f6a57033	8	#include <linux/sched.h>
1da177e4 LT	9	#include <linux/cpu.h>
	10	#include <linux/topology.h>
	11	#include <linux/device.h>
76b67ed9	12	#include <linux/node.h>
1da177e4	13
a1bdc7aa	14	#include "base.h"
1da177e4 LT	15
1da177e4 LT	16	struct sysdev_class cpu_sysdev_class = {
af5ca3f4	17	.name = "cpu",
1da177e4 LT	18	};
	19	EXPORT_SYMBOL(cpu_sysdev_class);
	20
e37d05da	21	static DEFINE_PER_CPU(struct sys_device *, cpu_sys_devices);
ad74557a	22
1da177e4	23	#ifdef CONFIG_HOTPLUG_CPU
4a0b2b4d AK	24	static ssize_t show_online(struct sys_device dev, struct sysdev_attribute attr,
4a0b2b4d AK	25	char *buf)
1da177e4 LT	26	{
	27	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
	28
	29	return sprintf(buf, "%u\n", !!cpu_online(cpu->sysdev.id));
	30	}
	31
4a0b2b4d AK	32	static ssize_t __ref store_online(struct sys_device dev, struct sysdev_attribute attr,
4a0b2b4d AK	33	const char *buf, size_t count)
1da177e4 LT	34	{
	35	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
	36	ssize_t ret;
	37
	38	switch (buf[0]) {
	39	case '0':
	40	ret = cpu_down(cpu->sysdev.id);
	41	if (!ret)
312c004d	42	kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
1da177e4 LT	43	break;
1da177e4 LT	44	case '1':
34f361ad	45	ret = cpu_up(cpu->sysdev.id);
fb69c390	46	if (!ret)
312c004d	47	kobject_uevent(&dev->kobj, KOBJ_ONLINE);
1da177e4 LT	48	break;
	49	default:
	50	ret = -EINVAL;
	51	}
	52
	53	if (ret >= 0)
	54	ret = count;
	55	return ret;
	56	}
9eb3ff40	57	static SYSDEV_ATTR(online, 0644, show_online, store_online);
1da177e4	58
6c847402	59	static void __cpuinit register_cpu_control(struct cpu *cpu)
1da177e4 LT	60	{
	61	sysdev_create_file(&cpu->sysdev, &attr_online);
	62	}
76b67ed9	63	void unregister_cpu(struct cpu *cpu)
1da177e4	64	{
ad74557a	65	int logical_cpu = cpu->sysdev.id;
1da177e4	66
76b67ed9 KH	67	unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));
76b67ed9 KH	68
1da177e4 LT	69	sysdev_remove_file(&cpu->sysdev, &attr_online);
	70
	71	sysdev_unregister(&cpu->sysdev);
e37d05da	72	per_cpu(cpu_sys_devices, logical_cpu) = NULL;
1da177e4 LT	73	return;
1da177e4 LT	74	}
12633e80 NF	75
	76	#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
	77	static ssize_t cpu_probe_store(struct class class, const char buf,
	78	size_t count)
	79	{
	80	return arch_cpu_probe(buf, count);
	81	}
	82
	83	static ssize_t cpu_release_store(struct class class, const char buf,
	84	size_t count)
	85	{
	86	return arch_cpu_release(buf, count);
	87	}
	88
	89	static CLASS_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
	90	static CLASS_ATTR(release, S_IWUSR, NULL, cpu_release_store);
	91
	92	int __init cpu_probe_release_init(void)
	93	{
	94	int rc;
	95
	96	rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
	97	&class_attr_probe.attr);
	98	if (!rc)
	99	rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
	100	&class_attr_release.attr);
	101
	102	return rc;
	103	}
	104	device_initcall(cpu_probe_release_init);
	105	#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
	106
1da177e4 LT	107	#else /* ... !CONFIG_HOTPLUG_CPU */
	108	static inline void register_cpu_control(struct cpu *cpu)
	109	{
	110	}
	111	#endif /* CONFIG_HOTPLUG_CPU */
	112
51be5606 VG	113	#ifdef CONFIG_KEXEC
	114	#include <linux/kexec.h>
	115
4a0b2b4d AK	116	static ssize_t show_crash_notes(struct sys_device dev, struct sysdev_attribute attr,
4a0b2b4d AK	117	char *buf)
51be5606 VG	118	{
	119	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
	120	ssize_t rc;
	121	unsigned long long addr;
	122	int cpunum;
	123
	124	cpunum = cpu->sysdev.id;
	125
	126	/*
	127	* Might be reading other cpu's data based on which cpu read thread
	128	* has been scheduled. But cpu data (memory) is allocated once during
	129	* boot up and this data does not change there after. Hence this
	130	* operation should be safe. No locking required.
	131	*/
51be5606 VG	132	addr = __pa(per_cpu_ptr(crash_notes, cpunum));
51be5606 VG	133	rc = sprintf(buf, "%Lx\n", addr);
51be5606 VG	134	return rc;
	135	}
	136	static SYSDEV_ATTR(crash_notes, 0400, show_crash_notes, NULL);
	137	#endif
	138
9d1fe323 MT	139	/*
	140	* Print cpu online, possible, present, and system maps
	141	*/
f7df8ed1	142	static ssize_t print_cpus_map(char buf, const struct cpumask map)
9d1fe323	143	{
29c0177e	144	int n = cpulist_scnprintf(buf, PAGE_SIZE-2, map);
9d1fe323 MT	145
	146	buf[n++] = '\n';
	147	buf[n] = '\0';
	148	return n;
	149	}
	150
	151	#define print_cpus_func(type) \
	152	static ssize_t print_cpus_##type(struct sysdev_class class, char buf) \
	153	{ \
aa85ea5b	154	return print_cpus_map(buf, cpu_##type##_mask); \
9d1fe323	155	} \
143aa5c5	156	static struct sysdev_class_attribute attr_##type##_map = \
9d1fe323 MT	157	_SYSDEV_CLASS_ATTR(type, 0444, print_cpus_##type, NULL)
	158
	159	print_cpus_func(online);
	160	print_cpus_func(possible);
	161	print_cpus_func(present);
	162
e057d7ae MT	163	/*
	164	* Print values for NR_CPUS and offlined cpus
	165	*/
	166	static ssize_t print_cpus_kernel_max(struct sysdev_class class, char buf)
	167	{
8fd2d2d5	168	int n = snprintf(buf, PAGE_SIZE-2, "%d\n", NR_CPUS - 1);
e057d7ae MT	169	return n;
	170	}
	171	static SYSDEV_CLASS_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL);
	172
	173	/* arch-optional setting to enable display of offline cpus >= nr_cpu_ids */
	174	unsigned int total_cpus;
	175
	176	static ssize_t print_cpus_offline(struct sysdev_class class, char buf)
	177	{
	178	int n = 0, len = PAGE_SIZE-2;
	179	cpumask_var_t offline;
	180
	181	/* display offline cpus < nr_cpu_ids */
	182	if (!alloc_cpumask_var(&offline, GFP_KERNEL))
	183	return -ENOMEM;
	184	cpumask_complement(offline, cpu_online_mask);
	185	n = cpulist_scnprintf(buf, len, offline);
	186	free_cpumask_var(offline);
	187
	188	/* display offline cpus >= nr_cpu_ids */
	189	if (total_cpus && nr_cpu_ids < total_cpus) {
	190	if (n && n < len)
	191	buf[n++] = ',';
	192
	193	if (nr_cpu_ids == total_cpus-1)
	194	n += snprintf(&buf[n], len - n, "%d", nr_cpu_ids);
	195	else
	196	n += snprintf(&buf[n], len - n, "%d-%d",
	197	nr_cpu_ids, total_cpus-1);
	198	}
	199
	200	n += snprintf(&buf[n], len - n, "\n");
	201	return n;
	202	}
	203	static SYSDEV_CLASS_ATTR(offline, 0444, print_cpus_offline, NULL);
	204
143aa5c5	205	static struct sysdev_class_attribute *cpu_state_attr[] = {
9d1fe323 MT	206	&attr_online_map,
	207	&attr_possible_map,
	208	&attr_present_map,
e057d7ae MT	209	&attr_kernel_max,
e057d7ae MT	210	&attr_offline,
9d1fe323 MT	211	};
	212
	213	static int cpu_states_init(void)
	214	{
	215	int i;
	216	int err = 0;
	217
	218	for (i = 0; i < ARRAY_SIZE(cpu_state_attr); i++) {
	219	int ret;
	220	ret = sysdev_class_create_file(&cpu_sysdev_class,
	221	cpu_state_attr[i]);
	222	if (!err)
	223	err = ret;
	224	}
	225	return err;
	226	}
	227
1da177e4	228	/*
405ae7d3	229	* register_cpu - Setup a sysfs device for a CPU.
72486f1f SS	230	* @cpu - cpu->hotpluggable field set to 1 will generate a control file in
72486f1f SS	231	* sysfs for this CPU.
1da177e4 LT	232	* @num - CPU number to use when creating the device.
	233	*
	234	* Initialize and register the CPU device.
	235	*/
33b5f31b	236	int __cpuinit register_cpu(struct cpu *cpu, int num)
1da177e4 LT	237	{
1da177e4 LT	238	int error;
1da177e4 LT	239	cpu->node_id = cpu_to_node(num);
	240	cpu->sysdev.id = num;
	241	cpu->sysdev.cls = &cpu_sysdev_class;
	242
	243	error = sysdev_register(&cpu->sysdev);
76b67ed9	244
72486f1f	245	if (!error && cpu->hotpluggable)
1da177e4	246	register_cpu_control(cpu);
ad74557a	247	if (!error)
e37d05da	248	per_cpu(cpu_sys_devices, num) = &cpu->sysdev;
76b67ed9 KH	249	if (!error)
76b67ed9 KH	250	register_cpu_under_node(num, cpu_to_node(num));
51be5606 VG	251
	252	#ifdef CONFIG_KEXEC
	253	if (!error)
	254	error = sysdev_create_file(&cpu->sysdev, &attr_crash_notes);
	255	#endif
1da177e4 LT	256	return error;
	257	}
	258
a29d642a	259	struct sys_device *get_cpu_sysdev(unsigned cpu)
ad74557a	260	{
e37d05da MT	261	if (cpu < nr_cpu_ids && cpu_possible(cpu))
e37d05da MT	262	return per_cpu(cpu_sys_devices, cpu);
ad74557a AR	263	else
	264	return NULL;
	265	}
	266	EXPORT_SYMBOL_GPL(get_cpu_sysdev);
1da177e4 LT	267
	268	int __init cpu_dev_init(void)
	269	{
5c45bf27 SS	270	int err;
	271
	272	err = sysdev_class_register(&cpu_sysdev_class);
9d1fe323 MT	273	if (!err)
	274	err = cpu_states_init();
	275
5c45bf27 SS	276	#if defined(CONFIG_SCHED_MC) \|\| defined(CONFIG_SCHED_SMT)
	277	if (!err)
	278	err = sched_create_sysfs_power_savings_entries(&cpu_sysdev_class);
	279	#endif
	280
	281	return err;
1da177e4	282	}