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

/*
 * CPU subsystem support
 */

#include <linux/kernel.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 <linux/gfp.h>
#include <linux/slab.h>
#include <linux/percpu.h>
#include <linux/acpi.h>
#include <linux/of.h>

#include "base.h"

static DEFINE_PER_CPU(struct device *, cpu_sys_devices);

static int cpu_subsys_match(struct device *dev, struct device_driver *drv)
{
	/* ACPI style match is the only one that may succeed. */
	if (acpi_driver_match_device(dev, drv))
		return 1;

	return 0;
}

#ifdef CONFIG_HOTPLUG_CPU
static void change_cpu_under_node(struct cpu *cpu,
			unsigned int from_nid, unsigned int to_nid)
{
	int cpuid = cpu->dev.id;
	unregister_cpu_under_node(cpuid, from_nid);
	register_cpu_under_node(cpuid, to_nid);
	cpu->node_id = to_nid;
}

static int __ref cpu_subsys_online(struct device *dev)
{
	struct cpu *cpu = container_of(dev, struct cpu, dev);
	int cpuid = dev->id;
	int from_nid, to_nid;
	int ret = -ENODEV;

	cpu_hotplug_driver_lock();

	from_nid = cpu_to_node(cpuid);
	if (from_nid == NUMA_NO_NODE)
		goto out;

	ret = cpu_up(cpuid);
	/*
	 * When hot adding memory to memoryless node and enabling a cpu
	 * on the node, node number of the cpu may internally change.
	 */
	to_nid = cpu_to_node(cpuid);
	if (from_nid != to_nid)
		change_cpu_under_node(cpu, from_nid, to_nid);

 out:
	cpu_hotplug_driver_unlock();
	return ret;
}

static int cpu_subsys_offline(struct device *dev)
{
	int ret;

	cpu_hotplug_driver_lock();
	ret = cpu_down(dev->id);
	cpu_hotplug_driver_unlock();
	return ret;
}

void unregister_cpu(struct cpu *cpu)
{
	int logical_cpu = cpu->dev.id;

	unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));

	device_unregister(&cpu->dev);
	per_cpu(cpu_sys_devices, logical_cpu) = NULL;
	return;
}

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

static ssize_t cpu_release_store(struct device *dev,
				 struct device_attribute *attr,
				 const char *buf,
				 size_t count)
{
	return arch_cpu_release(buf, count);
}

static DEVICE_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
static DEVICE_ATTR(release, S_IWUSR, NULL, cpu_release_store);
#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
#endif /* CONFIG_HOTPLUG_CPU */

struct bus_type cpu_subsys = {
	.name = "cpu",
	.dev_name = "cpu",
	.match = cpu_subsys_match,
#ifdef CONFIG_HOTPLUG_CPU
	.online = cpu_subsys_online,
	.offline = cpu_subsys_offline,
#endif
};
EXPORT_SYMBOL_GPL(cpu_subsys);

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

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

	cpunum = cpu->dev.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 = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpunum));
	rc = sprintf(buf, "%Lx\n", addr);
	return rc;
}
static DEVICE_ATTR(crash_notes, 0400, show_crash_notes, NULL);

static ssize_t show_crash_notes_size(struct device *dev,
				     struct device_attribute *attr,
				     char *buf)
{
	ssize_t rc;

	rc = sprintf(buf, "%zu\n", sizeof(note_buf_t));
	return rc;
}
static DEVICE_ATTR(crash_notes_size, 0400, show_crash_notes_size, NULL);

static struct attribute *crash_note_cpu_attrs[] = {
	&dev_attr_crash_notes.attr,
	&dev_attr_crash_notes_size.attr,
	NULL
};

static struct attribute_group crash_note_cpu_attr_group = {
	.attrs = crash_note_cpu_attrs,
};
#endif

static const struct attribute_group *common_cpu_attr_groups[] = {
#ifdef CONFIG_KEXEC
	&crash_note_cpu_attr_group,
#endif
	NULL
};

static const struct attribute_group *hotplugable_cpu_attr_groups[] = {
#ifdef CONFIG_KEXEC
	&crash_note_cpu_attr_group,
#endif
	NULL
};

/*
 * Print cpu online, possible, present, and system maps
 */

struct cpu_attr {
	struct device_attribute attr;
	const struct cpumask *const * const map;
};

static ssize_t show_cpus_attr(struct device *dev,
			      struct device_attribute *attr,
			      char *buf)
{
	struct cpu_attr *ca = container_of(attr, struct cpu_attr, attr);
	int n = cpulist_scnprintf(buf, PAGE_SIZE-2, *(ca->map));

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

#define _CPU_ATTR(name, map) \
	{ __ATTR(name, 0444, show_cpus_attr, NULL), map }

/* Keep in sync with cpu_subsys_attrs */
static struct cpu_attr cpu_attrs[] = {
	_CPU_ATTR(online, &cpu_online_mask),
	_CPU_ATTR(possible, &cpu_possible_mask),
	_CPU_ATTR(present, &cpu_present_mask),
};

/*
 * Print values for NR_CPUS and offlined cpus
 */
static ssize_t print_cpus_kernel_max(struct device *dev,
				     struct device_attribute *attr, char *buf)
{
	int n = snprintf(buf, PAGE_SIZE-2, "%d\n", NR_CPUS - 1);
	return n;
}
static DEVICE_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 device *dev,
				  struct device_attribute *attr, 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_andnot(offline, cpu_possible_mask, 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 DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL);

static void cpu_device_release(struct device *dev)
{
	/*
	 * This is an empty function to prevent the driver core from spitting a
	 * warning at us.  Yes, I know this is directly opposite of what the
	 * documentation for the driver core and kobjects say, and the author
	 * of this code has already been publically ridiculed for doing
	 * something as foolish as this.  However, at this point in time, it is
	 * the only way to handle the issue of statically allocated cpu
	 * devices.  The different architectures will have their cpu device
	 * code reworked to properly handle this in the near future, so this
	 * function will then be changed to correctly free up the memory held
	 * by the cpu device.
	 *
	 * Never copy this way of doing things, or you too will be made fun of
	 * on the linux-kernel list, you have been warned.
	 */
}

/*
 * 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 register_cpu(struct cpu *cpu, int num)
{
	int error;

	cpu->node_id = cpu_to_node(num);
	memset(&cpu->dev, 0x00, sizeof(struct device));
	cpu->dev.id = num;
	cpu->dev.bus = &cpu_subsys;
	cpu->dev.release = cpu_device_release;
	cpu->dev.offline_disabled = !cpu->hotpluggable;
	cpu->dev.offline = !cpu_online(num);
	cpu->dev.of_node = of_get_cpu_node(num, NULL);
#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
	cpu->dev.bus->uevent = arch_cpu_uevent;
#endif
	cpu->dev.groups = common_cpu_attr_groups;
	if (cpu->hotpluggable)
		cpu->dev.groups = hotplugable_cpu_attr_groups;
	error = device_register(&cpu->dev);
	if (!error)
		per_cpu(cpu_sys_devices, num) = &cpu->dev;
	if (!error)
		register_cpu_under_node(num, cpu_to_node(num));

	return error;
}

struct device *get_cpu_device(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_device);

#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
static DEVICE_ATTR(modalias, 0444, arch_print_cpu_modalias, NULL);
#endif

static struct attribute *cpu_root_attrs[] = {
#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
	&dev_attr_probe.attr,
	&dev_attr_release.attr,
#endif
	&cpu_attrs[0].attr.attr,
	&cpu_attrs[1].attr.attr,
	&cpu_attrs[2].attr.attr,
	&dev_attr_kernel_max.attr,
	&dev_attr_offline.attr,
#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
	&dev_attr_modalias.attr,
#endif
	NULL
};

static struct attribute_group cpu_root_attr_group = {
	.attrs = cpu_root_attrs,
};

static const struct attribute_group *cpu_root_attr_groups[] = {
	&cpu_root_attr_group,
	NULL,
};

bool cpu_is_hotpluggable(unsigned cpu)
{
	struct device *dev = get_cpu_device(cpu);
	return dev && container_of(dev, struct cpu, dev)->hotpluggable;
}
EXPORT_SYMBOL_GPL(cpu_is_hotpluggable);

#ifdef CONFIG_GENERIC_CPU_DEVICES
static DEFINE_PER_CPU(struct cpu, cpu_devices);
#endif

static void __init cpu_dev_register_generic(void)
{
#ifdef CONFIG_GENERIC_CPU_DEVICES
	int i;

	for_each_possible_cpu(i) {
		if (register_cpu(&per_cpu(cpu_devices, i), i))
			panic("Failed to register CPU device");
	}
#endif
}

void __init cpu_dev_init(void)
{
	if (subsys_system_register(&cpu_subsys, cpu_root_attr_groups))
		panic("Failed to register CPU subsystem");

	cpu_dev_register_generic();
}
Commit	Line	Data
1da177e4	1	/*
8a25a2fd	2	* CPU subsystem support
1da177e4 LT	3	*/
1da177e4 LT	4
024f7846	5	#include <linux/kernel.h>
1da177e4 LT	6	#include <linux/module.h>
1da177e4 LT	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>
5a0e3ad6	13	#include <linux/gfp.h>
fad12ac8	14	#include <linux/slab.h>
9f13a1fd	15	#include <linux/percpu.h>
ac212b69	16	#include <linux/acpi.h>
f86e4718	17	#include <linux/of.h>
1da177e4	18
a1bdc7aa	19	#include "base.h"
1da177e4	20
8a25a2fd	21	static DEFINE_PER_CPU(struct device *, cpu_sys_devices);
ad74557a	22
ac212b69 RW	23	static int cpu_subsys_match(struct device dev, struct device_driver drv)
	24	{
	25	/* ACPI style match is the only one that may succeed. */
	26	if (acpi_driver_match_device(dev, drv))
	27	return 1;
	28
	29	return 0;
	30	}
	31
1da177e4	32	#ifdef CONFIG_HOTPLUG_CPU
34640468 YI	33	static void change_cpu_under_node(struct cpu *cpu,
	34	unsigned int from_nid, unsigned int to_nid)
	35	{
	36	int cpuid = cpu->dev.id;
	37	unregister_cpu_under_node(cpuid, from_nid);
	38	register_cpu_under_node(cpuid, to_nid);
	39	cpu->node_id = to_nid;
	40	}
	41
0902a904	42	static int __ref cpu_subsys_online(struct device *dev)
1da177e4	43	{
8a25a2fd	44	struct cpu *cpu = container_of(dev, struct cpu, dev);
0902a904 RW	45	int cpuid = dev->id;
0902a904 RW	46	int from_nid, to_nid;
c7991b0b	47	int ret = -ENODEV;
0902a904 RW	48
0902a904 RW	49	cpu_hotplug_driver_lock();
1da177e4	50
0902a904	51	from_nid = cpu_to_node(cpuid);
c7991b0b RW	52	if (from_nid == NUMA_NO_NODE)
	53	goto out;
	54
0902a904 RW	55	ret = cpu_up(cpuid);
	56	/*
	57	* When hot adding memory to memoryless node and enabling a cpu
	58	* on the node, node number of the cpu may internally change.
	59	*/
	60	to_nid = cpu_to_node(cpuid);
	61	if (from_nid != to_nid)
	62	change_cpu_under_node(cpu, from_nid, to_nid);
1da177e4	63
c7991b0b	64	out:
0902a904 RW	65	cpu_hotplug_driver_unlock();
0902a904 RW	66	return ret;
1da177e4 LT	67	}
1da177e4 LT	68
0902a904	69	static int cpu_subsys_offline(struct device *dev)
1da177e4	70	{
0902a904	71	int ret;
1da177e4	72
51badebd	73	cpu_hotplug_driver_lock();
0902a904	74	ret = cpu_down(dev->id);
51badebd	75	cpu_hotplug_driver_unlock();
1da177e4 LT	76	return ret;
1da177e4 LT	77	}
1c4e2d70	78
76b67ed9	79	void unregister_cpu(struct cpu *cpu)
1da177e4	80	{
8a25a2fd	81	int logical_cpu = cpu->dev.id;
1da177e4	82
76b67ed9 KH	83	unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));
76b67ed9 KH	84
8a25a2fd	85	device_unregister(&cpu->dev);
e37d05da	86	per_cpu(cpu_sys_devices, logical_cpu) = NULL;
1da177e4 LT	87	return;
1da177e4 LT	88	}
12633e80 NF	89
12633e80 NF	90	#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
8a25a2fd KS	91	static ssize_t cpu_probe_store(struct device *dev,
8a25a2fd KS	92	struct device_attribute *attr,
67fc233f	93	const char *buf,
12633e80 NF	94	size_t count)
	95	{
	96	return arch_cpu_probe(buf, count);
	97	}
	98
8a25a2fd KS	99	static ssize_t cpu_release_store(struct device *dev,
8a25a2fd KS	100	struct device_attribute *attr,
67fc233f	101	const char *buf,
12633e80 NF	102	size_t count)
	103	{
	104	return arch_cpu_release(buf, count);
	105	}
	106
8a25a2fd KS	107	static DEVICE_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
8a25a2fd KS	108	static DEVICE_ATTR(release, S_IWUSR, NULL, cpu_release_store);
12633e80	109	#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
1da177e4 LT	110	#endif /* CONFIG_HOTPLUG_CPU */
1da177e4 LT	111
0902a904 RW	112	struct bus_type cpu_subsys = {
	113	.name = "cpu",
	114	.dev_name = "cpu",
ac212b69	115	.match = cpu_subsys_match,
0902a904 RW	116	#ifdef CONFIG_HOTPLUG_CPU
	117	.online = cpu_subsys_online,
	118	.offline = cpu_subsys_offline,
	119	#endif
	120	};
	121	EXPORT_SYMBOL_GPL(cpu_subsys);
	122
51be5606 VG	123	#ifdef CONFIG_KEXEC
	124	#include <linux/kexec.h>
	125
8a25a2fd	126	static ssize_t show_crash_notes(struct device dev, struct device_attribute attr,
4a0b2b4d	127	char *buf)
51be5606	128	{
8a25a2fd	129	struct cpu *cpu = container_of(dev, struct cpu, dev);
51be5606 VG	130	ssize_t rc;
	131	unsigned long long addr;
	132	int cpunum;
	133
8a25a2fd	134	cpunum = cpu->dev.id;
51be5606 VG	135
	136	/*
	137	* Might be reading other cpu's data based on which cpu read thread
	138	* has been scheduled. But cpu data (memory) is allocated once during
	139	* boot up and this data does not change there after. Hence this
	140	* operation should be safe. No locking required.
	141	*/
3b034b0d	142	addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpunum));
51be5606	143	rc = sprintf(buf, "%Lx\n", addr);
51be5606 VG	144	return rc;
51be5606 VG	145	}
8a25a2fd	146	static DEVICE_ATTR(crash_notes, 0400, show_crash_notes, NULL);
eca4549f ZY	147
	148	static ssize_t show_crash_notes_size(struct device *dev,
	149	struct device_attribute *attr,
	150	char *buf)
	151	{
	152	ssize_t rc;
	153
bcfb87fb	154	rc = sprintf(buf, "%zu\n", sizeof(note_buf_t));
eca4549f ZY	155	return rc;
	156	}
	157	static DEVICE_ATTR(crash_notes_size, 0400, show_crash_notes_size, NULL);
c055da9f IM	158
	159	static struct attribute *crash_note_cpu_attrs[] = {
	160	&dev_attr_crash_notes.attr,
	161	&dev_attr_crash_notes_size.attr,
	162	NULL
	163	};
	164
	165	static struct attribute_group crash_note_cpu_attr_group = {
	166	.attrs = crash_note_cpu_attrs,
	167	};
	168	#endif
	169
	170	static const struct attribute_group *common_cpu_attr_groups[] = {
	171	#ifdef CONFIG_KEXEC
	172	&crash_note_cpu_attr_group,
51be5606	173	#endif
c055da9f IM	174	NULL
c055da9f IM	175	};
51be5606	176
1c4e2d70 IM	177	static const struct attribute_group *hotplugable_cpu_attr_groups[] = {
	178	#ifdef CONFIG_KEXEC
	179	&crash_note_cpu_attr_group,
1c4e2d70 IM	180	#endif
	181	NULL
	182	};
	183
9d1fe323 MT	184	/*
	185	* Print cpu online, possible, present, and system maps
	186	*/
265d2e2e AK	187
265d2e2e AK	188	struct cpu_attr {
8a25a2fd	189	struct device_attribute attr;
265d2e2e AK	190	const struct cpumask const const map;
	191	};
	192
8a25a2fd KS	193	static ssize_t show_cpus_attr(struct device *dev,
8a25a2fd KS	194	struct device_attribute *attr,
265d2e2e	195	char *buf)
9d1fe323	196	{
265d2e2e AK	197	struct cpu_attr *ca = container_of(attr, struct cpu_attr, attr);
265d2e2e AK	198	int n = cpulist_scnprintf(buf, PAGE_SIZE-2, *(ca->map));
9d1fe323 MT	199
	200	buf[n++] = '\n';
	201	buf[n] = '\0';
	202	return n;
	203	}
	204
8a25a2fd KS	205	#define _CPU_ATTR(name, map) \
8a25a2fd KS	206	{ __ATTR(name, 0444, show_cpus_attr, NULL), map }
9d1fe323	207
8a25a2fd	208	/* Keep in sync with cpu_subsys_attrs */
265d2e2e AK	209	static struct cpu_attr cpu_attrs[] = {
	210	_CPU_ATTR(online, &cpu_online_mask),
	211	_CPU_ATTR(possible, &cpu_possible_mask),
	212	_CPU_ATTR(present, &cpu_present_mask),
	213	};
9d1fe323	214
e057d7ae MT	215	/*
	216	* Print values for NR_CPUS and offlined cpus
	217	*/
8a25a2fd KS	218	static ssize_t print_cpus_kernel_max(struct device *dev,
8a25a2fd KS	219	struct device_attribute attr, char buf)
e057d7ae	220	{
8fd2d2d5	221	int n = snprintf(buf, PAGE_SIZE-2, "%d\n", NR_CPUS - 1);
e057d7ae MT	222	return n;
e057d7ae MT	223	}
8a25a2fd	224	static DEVICE_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL);
e057d7ae MT	225
	226	/* arch-optional setting to enable display of offline cpus >= nr_cpu_ids */
	227	unsigned int total_cpus;
	228
8a25a2fd KS	229	static ssize_t print_cpus_offline(struct device *dev,
8a25a2fd KS	230	struct device_attribute attr, char buf)
e057d7ae MT	231	{
	232	int n = 0, len = PAGE_SIZE-2;
	233	cpumask_var_t offline;
	234
	235	/* display offline cpus < nr_cpu_ids */
	236	if (!alloc_cpumask_var(&offline, GFP_KERNEL))
	237	return -ENOMEM;
cdc6e3d3	238	cpumask_andnot(offline, cpu_possible_mask, cpu_online_mask);
e057d7ae MT	239	n = cpulist_scnprintf(buf, len, offline);
	240	free_cpumask_var(offline);
	241
	242	/* display offline cpus >= nr_cpu_ids */
	243	if (total_cpus && nr_cpu_ids < total_cpus) {
	244	if (n && n < len)
	245	buf[n++] = ',';
	246
	247	if (nr_cpu_ids == total_cpus-1)
	248	n += snprintf(&buf[n], len - n, "%d", nr_cpu_ids);
	249	else
	250	n += snprintf(&buf[n], len - n, "%d-%d",
	251	nr_cpu_ids, total_cpus-1);
	252	}
	253
	254	n += snprintf(&buf[n], len - n, "\n");
	255	return n;
	256	}
8a25a2fd	257	static DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL);
e057d7ae	258
2885e25c GKH	259	static void cpu_device_release(struct device *dev)
	260	{
	261	/*
	262	* This is an empty function to prevent the driver core from spitting a
	263	* warning at us. Yes, I know this is directly opposite of what the
	264	* documentation for the driver core and kobjects say, and the author
	265	* of this code has already been publically ridiculed for doing
	266	* something as foolish as this. However, at this point in time, it is
	267	* the only way to handle the issue of statically allocated cpu
	268	* devices. The different architectures will have their cpu device
	269	* code reworked to properly handle this in the near future, so this
	270	* function will then be changed to correctly free up the memory held
	271	* by the cpu device.
	272	*
	273	* Never copy this way of doing things, or you too will be made fun of
30a4840a	274	* on the linux-kernel list, you have been warned.
2885e25c GKH	275	*/
	276	}
	277
1da177e4	278	/*
405ae7d3	279	* register_cpu - Setup a sysfs device for a CPU.
72486f1f SS	280	* @cpu - cpu->hotpluggable field set to 1 will generate a control file in
72486f1f SS	281	* sysfs for this CPU.
1da177e4 LT	282	* @num - CPU number to use when creating the device.
	283	*
	284	* Initialize and register the CPU device.
	285	*/
a83048eb	286	int register_cpu(struct cpu *cpu, int num)
1da177e4 LT	287	{
1da177e4 LT	288	int error;
76b67ed9	289
8a25a2fd	290	cpu->node_id = cpu_to_node(num);
29bb5d4f	291	memset(&cpu->dev, 0x00, sizeof(struct device));
8a25a2fd KS	292	cpu->dev.id = num;
8a25a2fd KS	293	cpu->dev.bus = &cpu_subsys;
2885e25c	294	cpu->dev.release = cpu_device_release;
0902a904	295	cpu->dev.offline_disabled = !cpu->hotpluggable;
1001b4d4	296	cpu->dev.offline = !cpu_online(num);
f86e4718	297	cpu->dev.of_node = of_get_cpu_node(num, NULL);
fad12ac8 TR	298	#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
	299	cpu->dev.bus->uevent = arch_cpu_uevent;
	300	#endif
c055da9f	301	cpu->dev.groups = common_cpu_attr_groups;
1c4e2d70 IM	302	if (cpu->hotpluggable)
1c4e2d70 IM	303	cpu->dev.groups = hotplugable_cpu_attr_groups;
8a25a2fd	304	error = device_register(&cpu->dev);
ad74557a	305	if (!error)
8a25a2fd	306	per_cpu(cpu_sys_devices, num) = &cpu->dev;
76b67ed9 KH	307	if (!error)
76b67ed9 KH	308	register_cpu_under_node(num, cpu_to_node(num));
51be5606	309
1da177e4 LT	310	return error;
	311	}
	312
8a25a2fd	313	struct device *get_cpu_device(unsigned cpu)
ad74557a	314	{
e37d05da MT	315	if (cpu < nr_cpu_ids && cpu_possible(cpu))
e37d05da MT	316	return per_cpu(cpu_sys_devices, cpu);
ad74557a AR	317	else
	318	return NULL;
	319	}
8a25a2fd KS	320	EXPORT_SYMBOL_GPL(get_cpu_device);
8a25a2fd KS	321
fad12ac8 TR	322	#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
	323	static DEVICE_ATTR(modalias, 0444, arch_print_cpu_modalias, NULL);
	324	#endif
	325
8a25a2fd KS	326	static struct attribute *cpu_root_attrs[] = {
	327	#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
	328	&dev_attr_probe.attr,
	329	&dev_attr_release.attr,
	330	#endif
	331	&cpu_attrs[0].attr.attr,
	332	&cpu_attrs[1].attr.attr,
	333	&cpu_attrs[2].attr.attr,
	334	&dev_attr_kernel_max.attr,
	335	&dev_attr_offline.attr,
fad12ac8 TR	336	#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
	337	&dev_attr_modalias.attr,
	338	#endif
8a25a2fd KS	339	NULL
	340	};
	341
	342	static struct attribute_group cpu_root_attr_group = {
	343	.attrs = cpu_root_attrs,
	344	};
	345
	346	static const struct attribute_group *cpu_root_attr_groups[] = {
	347	&cpu_root_attr_group,
	348	NULL,
	349	};
1da177e4	350
2987557f JT	351	bool cpu_is_hotpluggable(unsigned cpu)
2987557f JT	352	{
7affca35 LT	353	struct device *dev = get_cpu_device(cpu);
7affca35 LT	354	return dev && container_of(dev, struct cpu, dev)->hotpluggable;
2987557f JT	355	}
	356	EXPORT_SYMBOL_GPL(cpu_is_hotpluggable);
	357
9f13a1fd BH	358	#ifdef CONFIG_GENERIC_CPU_DEVICES
	359	static DEFINE_PER_CPU(struct cpu, cpu_devices);
	360	#endif
	361
	362	static void __init cpu_dev_register_generic(void)
	363	{
	364	#ifdef CONFIG_GENERIC_CPU_DEVICES
	365	int i;
	366
	367	for_each_possible_cpu(i) {
	368	if (register_cpu(&per_cpu(cpu_devices, i), i))
	369	panic("Failed to register CPU device");
	370	}
	371	#endif
	372	}
	373
024f7846	374	void __init cpu_dev_init(void)
1da177e4	375	{
024f7846 BH	376	if (subsys_system_register(&cpu_subsys, cpu_root_attr_groups))
024f7846 BH	377	panic("Failed to register CPU subsystem");
8a25a2fd	378
9f13a1fd	379	cpu_dev_register_generic();
1da177e4	380	}