[mirror_ubuntu-bionic-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 "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;

	cpu_hotplug_driver_lock();

	from_nid = cpu_to_node(cpuid);
	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);

	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);
#endif

/*
 * 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 __cpuinit 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;
#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
	cpu->dev.bus->uevent = arch_cpu_uevent;
#endif
	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));

#ifdef CONFIG_KEXEC
	if (!error)
		error = device_create_file(&cpu->dev, &dev_attr_crash_notes);
	if (!error)
		error = device_create_file(&cpu->dev,
					   &dev_attr_crash_notes_size);
#endif
	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>
1da177e4	17
a1bdc7aa	18	#include "base.h"
1da177e4	19
8a25a2fd	20	static DEFINE_PER_CPU(struct device *, cpu_sys_devices);
ad74557a	21
ac212b69 RW	22	static int cpu_subsys_match(struct device dev, struct device_driver drv)
	23	{
	24	/* ACPI style match is the only one that may succeed. */
	25	if (acpi_driver_match_device(dev, drv))
	26	return 1;
	27
	28	return 0;
	29	}
	30
1da177e4	31	#ifdef CONFIG_HOTPLUG_CPU
34640468 YI	32	static void change_cpu_under_node(struct cpu *cpu,
	33	unsigned int from_nid, unsigned int to_nid)
	34	{
	35	int cpuid = cpu->dev.id;
	36	unregister_cpu_under_node(cpuid, from_nid);
	37	register_cpu_under_node(cpuid, to_nid);
	38	cpu->node_id = to_nid;
	39	}
	40
0902a904	41	static int __ref cpu_subsys_online(struct device *dev)
1da177e4	42	{
8a25a2fd	43	struct cpu *cpu = container_of(dev, struct cpu, dev);
0902a904 RW	44	int cpuid = dev->id;
	45	int from_nid, to_nid;
	46	int ret;
	47
	48	cpu_hotplug_driver_lock();
	49
	50	from_nid = cpu_to_node(cpuid);
	51	ret = cpu_up(cpuid);
	52	/*
	53	* When hot adding memory to memoryless node and enabling a cpu
	54	* on the node, node number of the cpu may internally change.
	55	*/
	56	to_nid = cpu_to_node(cpuid);
	57	if (from_nid != to_nid)
	58	change_cpu_under_node(cpu, from_nid, to_nid);
1da177e4	59
0902a904 RW	60	cpu_hotplug_driver_unlock();
0902a904 RW	61	return ret;
1da177e4 LT	62	}
1da177e4 LT	63
0902a904	64	static int cpu_subsys_offline(struct device *dev)
1da177e4	65	{
0902a904	66	int ret;
1da177e4	67
51badebd	68	cpu_hotplug_driver_lock();
0902a904	69	ret = cpu_down(dev->id);
51badebd	70	cpu_hotplug_driver_unlock();
1da177e4 LT	71	return ret;
1da177e4 LT	72	}
1da177e4	73
76b67ed9	74	void unregister_cpu(struct cpu *cpu)
1da177e4	75	{
8a25a2fd	76	int logical_cpu = cpu->dev.id;
1da177e4	77
76b67ed9 KH	78	unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));
76b67ed9 KH	79
8a25a2fd	80	device_unregister(&cpu->dev);
e37d05da	81	per_cpu(cpu_sys_devices, logical_cpu) = NULL;
1da177e4 LT	82	return;
1da177e4 LT	83	}
12633e80 NF	84
12633e80 NF	85	#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
8a25a2fd KS	86	static ssize_t cpu_probe_store(struct device *dev,
8a25a2fd KS	87	struct device_attribute *attr,
67fc233f	88	const char *buf,
12633e80 NF	89	size_t count)
	90	{
	91	return arch_cpu_probe(buf, count);
	92	}
	93
8a25a2fd KS	94	static ssize_t cpu_release_store(struct device *dev,
8a25a2fd KS	95	struct device_attribute *attr,
67fc233f	96	const char *buf,
12633e80 NF	97	size_t count)
	98	{
	99	return arch_cpu_release(buf, count);
	100	}
	101
8a25a2fd KS	102	static DEVICE_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
8a25a2fd KS	103	static DEVICE_ATTR(release, S_IWUSR, NULL, cpu_release_store);
12633e80 NF	104	#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
12633e80 NF	105
1da177e4 LT	106	#endif /* CONFIG_HOTPLUG_CPU */
1da177e4 LT	107
0902a904 RW	108	struct bus_type cpu_subsys = {
	109	.name = "cpu",
	110	.dev_name = "cpu",
ac212b69	111	.match = cpu_subsys_match,
0902a904 RW	112	#ifdef CONFIG_HOTPLUG_CPU
	113	.online = cpu_subsys_online,
	114	.offline = cpu_subsys_offline,
	115	#endif
	116	};
	117	EXPORT_SYMBOL_GPL(cpu_subsys);
	118
51be5606 VG	119	#ifdef CONFIG_KEXEC
	120	#include <linux/kexec.h>
	121
8a25a2fd	122	static ssize_t show_crash_notes(struct device dev, struct device_attribute attr,
4a0b2b4d	123	char *buf)
51be5606	124	{
8a25a2fd	125	struct cpu *cpu = container_of(dev, struct cpu, dev);
51be5606 VG	126	ssize_t rc;
	127	unsigned long long addr;
	128	int cpunum;
	129
8a25a2fd	130	cpunum = cpu->dev.id;
51be5606 VG	131
	132	/*
	133	* Might be reading other cpu's data based on which cpu read thread
	134	* has been scheduled. But cpu data (memory) is allocated once during
	135	* boot up and this data does not change there after. Hence this
	136	* operation should be safe. No locking required.
	137	*/
3b034b0d	138	addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpunum));
51be5606	139	rc = sprintf(buf, "%Lx\n", addr);
51be5606 VG	140	return rc;
51be5606 VG	141	}
8a25a2fd	142	static DEVICE_ATTR(crash_notes, 0400, show_crash_notes, NULL);
eca4549f ZY	143
	144	static ssize_t show_crash_notes_size(struct device *dev,
	145	struct device_attribute *attr,
	146	char *buf)
	147	{
	148	ssize_t rc;
	149
bcfb87fb	150	rc = sprintf(buf, "%zu\n", sizeof(note_buf_t));
eca4549f ZY	151	return rc;
	152	}
	153	static DEVICE_ATTR(crash_notes_size, 0400, show_crash_notes_size, NULL);
51be5606 VG	154	#endif
51be5606 VG	155
9d1fe323 MT	156	/*
	157	* Print cpu online, possible, present, and system maps
	158	*/
265d2e2e AK	159
265d2e2e AK	160	struct cpu_attr {
8a25a2fd	161	struct device_attribute attr;
265d2e2e AK	162	const struct cpumask const const map;
	163	};
	164
8a25a2fd KS	165	static ssize_t show_cpus_attr(struct device *dev,
8a25a2fd KS	166	struct device_attribute *attr,
265d2e2e	167	char *buf)
9d1fe323	168	{
265d2e2e AK	169	struct cpu_attr *ca = container_of(attr, struct cpu_attr, attr);
265d2e2e AK	170	int n = cpulist_scnprintf(buf, PAGE_SIZE-2, *(ca->map));
9d1fe323 MT	171
	172	buf[n++] = '\n';
	173	buf[n] = '\0';
	174	return n;
	175	}
	176
8a25a2fd KS	177	#define _CPU_ATTR(name, map) \
8a25a2fd KS	178	{ __ATTR(name, 0444, show_cpus_attr, NULL), map }
9d1fe323	179
8a25a2fd	180	/* Keep in sync with cpu_subsys_attrs */
265d2e2e AK	181	static struct cpu_attr cpu_attrs[] = {
	182	_CPU_ATTR(online, &cpu_online_mask),
	183	_CPU_ATTR(possible, &cpu_possible_mask),
	184	_CPU_ATTR(present, &cpu_present_mask),
	185	};
9d1fe323	186
e057d7ae MT	187	/*
	188	* Print values for NR_CPUS and offlined cpus
	189	*/
8a25a2fd KS	190	static ssize_t print_cpus_kernel_max(struct device *dev,
8a25a2fd KS	191	struct device_attribute attr, char buf)
e057d7ae	192	{
8fd2d2d5	193	int n = snprintf(buf, PAGE_SIZE-2, "%d\n", NR_CPUS - 1);
e057d7ae MT	194	return n;
e057d7ae MT	195	}
8a25a2fd	196	static DEVICE_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL);
e057d7ae MT	197
	198	/* arch-optional setting to enable display of offline cpus >= nr_cpu_ids */
	199	unsigned int total_cpus;
	200
8a25a2fd KS	201	static ssize_t print_cpus_offline(struct device *dev,
8a25a2fd KS	202	struct device_attribute attr, char buf)
e057d7ae MT	203	{
	204	int n = 0, len = PAGE_SIZE-2;
	205	cpumask_var_t offline;
	206
	207	/* display offline cpus < nr_cpu_ids */
	208	if (!alloc_cpumask_var(&offline, GFP_KERNEL))
	209	return -ENOMEM;
cdc6e3d3	210	cpumask_andnot(offline, cpu_possible_mask, cpu_online_mask);
e057d7ae MT	211	n = cpulist_scnprintf(buf, len, offline);
	212	free_cpumask_var(offline);
	213
	214	/* display offline cpus >= nr_cpu_ids */
	215	if (total_cpus && nr_cpu_ids < total_cpus) {
	216	if (n && n < len)
	217	buf[n++] = ',';
	218
	219	if (nr_cpu_ids == total_cpus-1)
	220	n += snprintf(&buf[n], len - n, "%d", nr_cpu_ids);
	221	else
	222	n += snprintf(&buf[n], len - n, "%d-%d",
	223	nr_cpu_ids, total_cpus-1);
	224	}
	225
	226	n += snprintf(&buf[n], len - n, "\n");
	227	return n;
	228	}
8a25a2fd	229	static DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL);
e057d7ae	230
2885e25c GKH	231	static void cpu_device_release(struct device *dev)
	232	{
	233	/*
	234	* This is an empty function to prevent the driver core from spitting a
	235	* warning at us. Yes, I know this is directly opposite of what the
	236	* documentation for the driver core and kobjects say, and the author
	237	* of this code has already been publically ridiculed for doing
	238	* something as foolish as this. However, at this point in time, it is
	239	* the only way to handle the issue of statically allocated cpu
	240	* devices. The different architectures will have their cpu device
	241	* code reworked to properly handle this in the near future, so this
	242	* function will then be changed to correctly free up the memory held
	243	* by the cpu device.
	244	*
	245	* Never copy this way of doing things, or you too will be made fun of
30a4840a	246	* on the linux-kernel list, you have been warned.
2885e25c GKH	247	*/
	248	}
	249
1da177e4	250	/*
405ae7d3	251	* register_cpu - Setup a sysfs device for a CPU.
72486f1f SS	252	* @cpu - cpu->hotpluggable field set to 1 will generate a control file in
72486f1f SS	253	* sysfs for this CPU.
1da177e4 LT	254	* @num - CPU number to use when creating the device.
	255	*
	256	* Initialize and register the CPU device.
	257	*/
33b5f31b	258	int __cpuinit register_cpu(struct cpu *cpu, int num)
1da177e4 LT	259	{
1da177e4 LT	260	int error;
76b67ed9	261
8a25a2fd	262	cpu->node_id = cpu_to_node(num);
29bb5d4f	263	memset(&cpu->dev, 0x00, sizeof(struct device));
8a25a2fd KS	264	cpu->dev.id = num;
8a25a2fd KS	265	cpu->dev.bus = &cpu_subsys;
2885e25c	266	cpu->dev.release = cpu_device_release;
0902a904	267	cpu->dev.offline_disabled = !cpu->hotpluggable;
fad12ac8 TR	268	#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
	269	cpu->dev.bus->uevent = arch_cpu_uevent;
	270	#endif
8a25a2fd	271	error = device_register(&cpu->dev);
ad74557a	272	if (!error)
8a25a2fd	273	per_cpu(cpu_sys_devices, num) = &cpu->dev;
76b67ed9 KH	274	if (!error)
76b67ed9 KH	275	register_cpu_under_node(num, cpu_to_node(num));
51be5606 VG	276
	277	#ifdef CONFIG_KEXEC
	278	if (!error)
8a25a2fd	279	error = device_create_file(&cpu->dev, &dev_attr_crash_notes);
eca4549f ZY	280	if (!error)
	281	error = device_create_file(&cpu->dev,
	282	&dev_attr_crash_notes_size);
51be5606	283	#endif
1da177e4 LT	284	return error;
	285	}
	286
8a25a2fd	287	struct device *get_cpu_device(unsigned cpu)
ad74557a	288	{
e37d05da MT	289	if (cpu < nr_cpu_ids && cpu_possible(cpu))
e37d05da MT	290	return per_cpu(cpu_sys_devices, cpu);
ad74557a AR	291	else
	292	return NULL;
	293	}
8a25a2fd KS	294	EXPORT_SYMBOL_GPL(get_cpu_device);
8a25a2fd KS	295
fad12ac8 TR	296	#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
	297	static DEVICE_ATTR(modalias, 0444, arch_print_cpu_modalias, NULL);
	298	#endif
	299
8a25a2fd KS	300	static struct attribute *cpu_root_attrs[] = {
	301	#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
	302	&dev_attr_probe.attr,
	303	&dev_attr_release.attr,
	304	#endif
	305	&cpu_attrs[0].attr.attr,
	306	&cpu_attrs[1].attr.attr,
	307	&cpu_attrs[2].attr.attr,
	308	&dev_attr_kernel_max.attr,
	309	&dev_attr_offline.attr,
fad12ac8 TR	310	#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
	311	&dev_attr_modalias.attr,
	312	#endif
8a25a2fd KS	313	NULL
	314	};
	315
	316	static struct attribute_group cpu_root_attr_group = {
	317	.attrs = cpu_root_attrs,
	318	};
	319
	320	static const struct attribute_group *cpu_root_attr_groups[] = {
	321	&cpu_root_attr_group,
	322	NULL,
	323	};
1da177e4	324
2987557f JT	325	bool cpu_is_hotpluggable(unsigned cpu)
2987557f JT	326	{
7affca35 LT	327	struct device *dev = get_cpu_device(cpu);
7affca35 LT	328	return dev && container_of(dev, struct cpu, dev)->hotpluggable;
2987557f JT	329	}
	330	EXPORT_SYMBOL_GPL(cpu_is_hotpluggable);
	331
9f13a1fd BH	332	#ifdef CONFIG_GENERIC_CPU_DEVICES
	333	static DEFINE_PER_CPU(struct cpu, cpu_devices);
	334	#endif
	335
	336	static void __init cpu_dev_register_generic(void)
	337	{
	338	#ifdef CONFIG_GENERIC_CPU_DEVICES
	339	int i;
	340
	341	for_each_possible_cpu(i) {
	342	if (register_cpu(&per_cpu(cpu_devices, i), i))
	343	panic("Failed to register CPU device");
	344	}
	345	#endif
	346	}
	347
024f7846	348	void __init cpu_dev_init(void)
1da177e4	349	{
024f7846 BH	350	if (subsys_system_register(&cpu_subsys, cpu_root_attr_groups))
024f7846 BH	351	panic("Failed to register CPU subsystem");
8a25a2fd	352
9f13a1fd	353	cpu_dev_register_generic();
1da177e4	354	}