[linux-block.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 <linux/cpufeature.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;

	from_nid = cpu_to_node(cpuid);
	if (from_nid == NUMA_NO_NODE)
		return -ENODEV;

	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);

	return ret;
}

static int cpu_subsys_offline(struct device *dev)
{
	return cpu_down(dev->id);
}

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)
{
	ssize_t cnt;
	int ret;

	ret = lock_device_hotplug_sysfs();
	if (ret)
		return ret;

	cnt = arch_cpu_probe(buf, count);

	unlock_device_hotplug();
	return cnt;
}

static ssize_t cpu_release_store(struct device *dev,
				 struct device_attribute *attr,
				 const char *buf,
				 size_t count)
{
	ssize_t cnt;
	int ret;

	ret = lock_device_hotplug_sysfs();
	if (ret)
		return ret;

	cnt = arch_cpu_release(buf, count);

	unlock_device_hotplug();
	return cnt;
}

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);

	return cpumap_print_to_pagebuf(true, buf, *ca->map);
}

#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 = scnprintf(buf, len, "%*pbl", cpumask_pr_args(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 ssize_t print_cpus_isolated(struct device *dev,
				  struct device_attribute *attr, char *buf)
{
	int n = 0, len = PAGE_SIZE-2;

	n = scnprintf(buf, len, "%*pbl\n", cpumask_pr_args(cpu_isolated_map));

	return n;
}
static DEVICE_ATTR(isolated, 0444, print_cpus_isolated, 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.
	 */
}

#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
static ssize_t print_cpu_modalias(struct device *dev,
				  struct device_attribute *attr,
				  char *buf)
{
	ssize_t n;
	u32 i;

	n = sprintf(buf, "cpu:type:" CPU_FEATURE_TYPEFMT ":feature:",
		    CPU_FEATURE_TYPEVAL);

	for (i = 0; i < MAX_CPU_FEATURES; i++)
		if (cpu_have_feature(i)) {
			if (PAGE_SIZE < n + sizeof(",XXXX\n")) {
				WARN(1, "CPU features overflow page\n");
				break;
			}
			n += sprintf(&buf[n], ",%04X", i);
		}
	buf[n++] = '\n';
	return n;
}

static int cpu_uevent(struct device *dev, struct kobj_uevent_env *env)
{
	char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
	if (buf) {
		print_cpu_modalias(NULL, NULL, buf);
		add_uevent_var(env, "MODALIAS=%s", buf);
		kfree(buf);
	}
	return 0;
}
#endif

/*
 * 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_GENERIC_CPU_AUTOPROBE
	cpu->dev.bus->uevent = 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);

static void device_create_release(struct device *dev)
{
	kfree(dev);
}

static struct device *
__cpu_device_create(struct device *parent, void *drvdata,
		    const struct attribute_group **groups,
		    const char *fmt, va_list args)
{
	struct device *dev = NULL;
	int retval = -ENODEV;

	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
	if (!dev) {
		retval = -ENOMEM;
		goto error;
	}

	device_initialize(dev);
	dev->parent = parent;
	dev->groups = groups;
	dev->release = device_create_release;
	dev_set_drvdata(dev, drvdata);

	retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
	if (retval)
		goto error;

	retval = device_add(dev);
	if (retval)
		goto error;

	return dev;

error:
	put_device(dev);
	return ERR_PTR(retval);
}

struct device *cpu_device_create(struct device *parent, void *drvdata,
				 const struct attribute_group **groups,
				 const char *fmt, ...)
{
	va_list vargs;
	struct device *dev;

	va_start(vargs, fmt);
	dev = __cpu_device_create(parent, drvdata, groups, fmt, vargs);
	va_end(vargs);
	return dev;
}
EXPORT_SYMBOL_GPL(cpu_device_create);

#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
static DEVICE_ATTR(modalias, 0444, 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,
	&dev_attr_isolated.attr,
#ifdef CONFIG_GENERIC_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>
67bad2fd	18	#include <linux/cpufeature.h>
1da177e4	19
a1bdc7aa	20	#include "base.h"
1da177e4	21
8a25a2fd	22	static DEFINE_PER_CPU(struct device *, cpu_sys_devices);
ad74557a	23
ac212b69 RW	24	static int cpu_subsys_match(struct device dev, struct device_driver drv)
	25	{
	26	/* ACPI style match is the only one that may succeed. */
	27	if (acpi_driver_match_device(dev, drv))
	28	return 1;
	29
	30	return 0;
	31	}
	32
1da177e4	33	#ifdef CONFIG_HOTPLUG_CPU
34640468 YI	34	static void change_cpu_under_node(struct cpu *cpu,
	35	unsigned int from_nid, unsigned int to_nid)
	36	{
	37	int cpuid = cpu->dev.id;
	38	unregister_cpu_under_node(cpuid, from_nid);
	39	register_cpu_under_node(cpuid, to_nid);
	40	cpu->node_id = to_nid;
	41	}
	42
0902a904	43	static int __ref cpu_subsys_online(struct device *dev)
1da177e4	44	{
8a25a2fd	45	struct cpu *cpu = container_of(dev, struct cpu, dev);
0902a904 RW	46	int cpuid = dev->id;
0902a904 RW	47	int from_nid, to_nid;
6dedcca6	48	int ret;
1da177e4	49
0902a904	50	from_nid = cpu_to_node(cpuid);
c7991b0b	51	if (from_nid == NUMA_NO_NODE)
6dedcca6	52	return -ENODEV;
c7991b0b	53
0902a904 RW	54	ret = cpu_up(cpuid);
	55	/*
	56	* When hot adding memory to memoryless node and enabling a cpu
	57	* on the node, node number of the cpu may internally change.
	58	*/
	59	to_nid = cpu_to_node(cpuid);
	60	if (from_nid != to_nid)
	61	change_cpu_under_node(cpu, from_nid, to_nid);
1da177e4	62
0902a904	63	return ret;
1da177e4 LT	64	}
1da177e4 LT	65
0902a904	66	static int cpu_subsys_offline(struct device *dev)
1da177e4	67	{
6dedcca6	68	return cpu_down(dev->id);
1da177e4	69	}
1c4e2d70	70
76b67ed9	71	void unregister_cpu(struct cpu *cpu)
1da177e4	72	{
8a25a2fd	73	int logical_cpu = cpu->dev.id;
1da177e4	74
76b67ed9 KH	75	unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));
76b67ed9 KH	76
8a25a2fd	77	device_unregister(&cpu->dev);
e37d05da	78	per_cpu(cpu_sys_devices, logical_cpu) = NULL;
1da177e4 LT	79	return;
1da177e4 LT	80	}
12633e80 NF	81
12633e80 NF	82	#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
8a25a2fd KS	83	static ssize_t cpu_probe_store(struct device *dev,
8a25a2fd KS	84	struct device_attribute *attr,
67fc233f	85	const char *buf,
12633e80 NF	86	size_t count)
12633e80 NF	87	{
574b851e TK	88	ssize_t cnt;
	89	int ret;
	90
	91	ret = lock_device_hotplug_sysfs();
	92	if (ret)
	93	return ret;
	94
	95	cnt = arch_cpu_probe(buf, count);
	96
	97	unlock_device_hotplug();
	98	return cnt;
12633e80 NF	99	}
12633e80 NF	100
8a25a2fd KS	101	static ssize_t cpu_release_store(struct device *dev,
8a25a2fd KS	102	struct device_attribute *attr,
67fc233f	103	const char *buf,
12633e80 NF	104	size_t count)
12633e80 NF	105	{
574b851e TK	106	ssize_t cnt;
	107	int ret;
	108
	109	ret = lock_device_hotplug_sysfs();
	110	if (ret)
	111	return ret;
	112
	113	cnt = arch_cpu_release(buf, count);
	114
	115	unlock_device_hotplug();
	116	return cnt;
12633e80 NF	117	}
12633e80 NF	118
8a25a2fd KS	119	static DEVICE_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
8a25a2fd KS	120	static DEVICE_ATTR(release, S_IWUSR, NULL, cpu_release_store);
12633e80	121	#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
1da177e4 LT	122	#endif /* CONFIG_HOTPLUG_CPU */
1da177e4 LT	123
0902a904 RW	124	struct bus_type cpu_subsys = {
	125	.name = "cpu",
	126	.dev_name = "cpu",
ac212b69	127	.match = cpu_subsys_match,
0902a904 RW	128	#ifdef CONFIG_HOTPLUG_CPU
	129	.online = cpu_subsys_online,
	130	.offline = cpu_subsys_offline,
	131	#endif
	132	};
	133	EXPORT_SYMBOL_GPL(cpu_subsys);
	134
51be5606 VG	135	#ifdef CONFIG_KEXEC
	136	#include <linux/kexec.h>
	137
8a25a2fd	138	static ssize_t show_crash_notes(struct device dev, struct device_attribute attr,
4a0b2b4d	139	char *buf)
51be5606	140	{
8a25a2fd	141	struct cpu *cpu = container_of(dev, struct cpu, dev);
51be5606 VG	142	ssize_t rc;
	143	unsigned long long addr;
	144	int cpunum;
	145
8a25a2fd	146	cpunum = cpu->dev.id;
51be5606 VG	147
	148	/*
	149	* Might be reading other cpu's data based on which cpu read thread
	150	* has been scheduled. But cpu data (memory) is allocated once during
	151	* boot up and this data does not change there after. Hence this
	152	* operation should be safe. No locking required.
	153	*/
3b034b0d	154	addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpunum));
51be5606	155	rc = sprintf(buf, "%Lx\n", addr);
51be5606 VG	156	return rc;
51be5606 VG	157	}
8a25a2fd	158	static DEVICE_ATTR(crash_notes, 0400, show_crash_notes, NULL);
eca4549f ZY	159
	160	static ssize_t show_crash_notes_size(struct device *dev,
	161	struct device_attribute *attr,
	162	char *buf)
	163	{
	164	ssize_t rc;
	165
bcfb87fb	166	rc = sprintf(buf, "%zu\n", sizeof(note_buf_t));
eca4549f ZY	167	return rc;
	168	}
	169	static DEVICE_ATTR(crash_notes_size, 0400, show_crash_notes_size, NULL);
c055da9f IM	170
	171	static struct attribute *crash_note_cpu_attrs[] = {
	172	&dev_attr_crash_notes.attr,
	173	&dev_attr_crash_notes_size.attr,
	174	NULL
	175	};
	176
	177	static struct attribute_group crash_note_cpu_attr_group = {
	178	.attrs = crash_note_cpu_attrs,
	179	};
	180	#endif
	181
	182	static const struct attribute_group *common_cpu_attr_groups[] = {
	183	#ifdef CONFIG_KEXEC
	184	&crash_note_cpu_attr_group,
51be5606	185	#endif
c055da9f IM	186	NULL
c055da9f IM	187	};
51be5606	188
1c4e2d70 IM	189	static const struct attribute_group *hotplugable_cpu_attr_groups[] = {
	190	#ifdef CONFIG_KEXEC
	191	&crash_note_cpu_attr_group,
1c4e2d70 IM	192	#endif
	193	NULL
	194	};
	195
9d1fe323 MT	196	/*
	197	* Print cpu online, possible, present, and system maps
	198	*/
265d2e2e AK	199
265d2e2e AK	200	struct cpu_attr {
8a25a2fd	201	struct device_attribute attr;
265d2e2e AK	202	const struct cpumask const const map;
	203	};
	204
8a25a2fd KS	205	static ssize_t show_cpus_attr(struct device *dev,
8a25a2fd KS	206	struct device_attribute *attr,
265d2e2e	207	char *buf)
9d1fe323	208	{
265d2e2e	209	struct cpu_attr *ca = container_of(attr, struct cpu_attr, attr);
9d1fe323	210
5aaba363	211	return cpumap_print_to_pagebuf(true, buf, *ca->map);
9d1fe323 MT	212	}
9d1fe323 MT	213
8a25a2fd KS	214	#define _CPU_ATTR(name, map) \
8a25a2fd KS	215	{ __ATTR(name, 0444, show_cpus_attr, NULL), map }
9d1fe323	216
8a25a2fd	217	/* Keep in sync with cpu_subsys_attrs */
265d2e2e AK	218	static struct cpu_attr cpu_attrs[] = {
	219	_CPU_ATTR(online, &cpu_online_mask),
	220	_CPU_ATTR(possible, &cpu_possible_mask),
	221	_CPU_ATTR(present, &cpu_present_mask),
	222	};
9d1fe323	223
e057d7ae MT	224	/*
	225	* Print values for NR_CPUS and offlined cpus
	226	*/
8a25a2fd KS	227	static ssize_t print_cpus_kernel_max(struct device *dev,
8a25a2fd KS	228	struct device_attribute attr, char buf)
e057d7ae	229	{
8fd2d2d5	230	int n = snprintf(buf, PAGE_SIZE-2, "%d\n", NR_CPUS - 1);
e057d7ae MT	231	return n;
e057d7ae MT	232	}
8a25a2fd	233	static DEVICE_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL);
e057d7ae MT	234
	235	/* arch-optional setting to enable display of offline cpus >= nr_cpu_ids */
	236	unsigned int total_cpus;
	237
8a25a2fd KS	238	static ssize_t print_cpus_offline(struct device *dev,
8a25a2fd KS	239	struct device_attribute attr, char buf)
e057d7ae MT	240	{
	241	int n = 0, len = PAGE_SIZE-2;
	242	cpumask_var_t offline;
	243
	244	/* display offline cpus < nr_cpu_ids */
	245	if (!alloc_cpumask_var(&offline, GFP_KERNEL))
	246	return -ENOMEM;
cdc6e3d3	247	cpumask_andnot(offline, cpu_possible_mask, cpu_online_mask);
f799b1a7	248	n = scnprintf(buf, len, "%*pbl", cpumask_pr_args(offline));
e057d7ae MT	249	free_cpumask_var(offline);
	250
	251	/* display offline cpus >= nr_cpu_ids */
	252	if (total_cpus && nr_cpu_ids < total_cpus) {
	253	if (n && n < len)
	254	buf[n++] = ',';
	255
	256	if (nr_cpu_ids == total_cpus-1)
	257	n += snprintf(&buf[n], len - n, "%d", nr_cpu_ids);
	258	else
	259	n += snprintf(&buf[n], len - n, "%d-%d",
	260	nr_cpu_ids, total_cpus-1);
	261	}
	262
	263	n += snprintf(&buf[n], len - n, "\n");
	264	return n;
	265	}
8a25a2fd	266	static DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL);
e057d7ae	267
59f30abe RR	268	static ssize_t print_cpus_isolated(struct device *dev,
	269	struct device_attribute attr, char buf)
	270	{
	271	int n = 0, len = PAGE_SIZE-2;
	272
	273	n = scnprintf(buf, len, "%*pbl\n", cpumask_pr_args(cpu_isolated_map));
	274
	275	return n;
	276	}
	277	static DEVICE_ATTR(isolated, 0444, print_cpus_isolated, NULL);
	278
2885e25c GKH	279	static void cpu_device_release(struct device *dev)
	280	{
	281	/*
	282	* This is an empty function to prevent the driver core from spitting a
	283	* warning at us. Yes, I know this is directly opposite of what the
	284	* documentation for the driver core and kobjects say, and the author
	285	* of this code has already been publically ridiculed for doing
	286	* something as foolish as this. However, at this point in time, it is
	287	* the only way to handle the issue of statically allocated cpu
	288	* devices. The different architectures will have their cpu device
	289	* code reworked to properly handle this in the near future, so this
	290	* function will then be changed to correctly free up the memory held
	291	* by the cpu device.
	292	*
	293	* Never copy this way of doing things, or you too will be made fun of
30a4840a	294	* on the linux-kernel list, you have been warned.
2885e25c GKH	295	*/
	296	}
	297
67bad2fd AB	298	#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
	299	static ssize_t print_cpu_modalias(struct device *dev,
	300	struct device_attribute *attr,
	301	char *buf)
	302	{
	303	ssize_t n;
	304	u32 i;
	305
	306	n = sprintf(buf, "cpu:type:" CPU_FEATURE_TYPEFMT ":feature:",
	307	CPU_FEATURE_TYPEVAL);
	308
	309	for (i = 0; i < MAX_CPU_FEATURES; i++)
	310	if (cpu_have_feature(i)) {
	311	if (PAGE_SIZE < n + sizeof(",XXXX\n")) {
	312	WARN(1, "CPU features overflow page\n");
	313	break;
	314	}
	315	n += sprintf(&buf[n], ",%04X", i);
	316	}
	317	buf[n++] = '\n';
	318	return n;
	319	}
67bad2fd AB	320
	321	static int cpu_uevent(struct device dev, struct kobj_uevent_env env)
	322	{
	323	char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
	324	if (buf) {
	325	print_cpu_modalias(NULL, NULL, buf);
	326	add_uevent_var(env, "MODALIAS=%s", buf);
	327	kfree(buf);
	328	}
	329	return 0;
	330	}
	331	#endif
	332
1da177e4	333	/*
405ae7d3	334	* register_cpu - Setup a sysfs device for a CPU.
72486f1f SS	335	* @cpu - cpu->hotpluggable field set to 1 will generate a control file in
72486f1f SS	336	* sysfs for this CPU.
1da177e4 LT	337	* @num - CPU number to use when creating the device.
	338	*
	339	* Initialize and register the CPU device.
	340	*/
a83048eb	341	int register_cpu(struct cpu *cpu, int num)
1da177e4 LT	342	{
1da177e4 LT	343	int error;
76b67ed9	344
8a25a2fd	345	cpu->node_id = cpu_to_node(num);
29bb5d4f	346	memset(&cpu->dev, 0x00, sizeof(struct device));
8a25a2fd KS	347	cpu->dev.id = num;
8a25a2fd KS	348	cpu->dev.bus = &cpu_subsys;
2885e25c	349	cpu->dev.release = cpu_device_release;
0902a904	350	cpu->dev.offline_disabled = !cpu->hotpluggable;
1001b4d4	351	cpu->dev.offline = !cpu_online(num);
f86e4718	352	cpu->dev.of_node = of_get_cpu_node(num, NULL);
2b9c1f03	353	#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
67bad2fd	354	cpu->dev.bus->uevent = cpu_uevent;
fad12ac8	355	#endif
c055da9f	356	cpu->dev.groups = common_cpu_attr_groups;
1c4e2d70 IM	357	if (cpu->hotpluggable)
1c4e2d70 IM	358	cpu->dev.groups = hotplugable_cpu_attr_groups;
8a25a2fd	359	error = device_register(&cpu->dev);
ad74557a	360	if (!error)
8a25a2fd	361	per_cpu(cpu_sys_devices, num) = &cpu->dev;
76b67ed9 KH	362	if (!error)
76b67ed9 KH	363	register_cpu_under_node(num, cpu_to_node(num));
51be5606	364
1da177e4 LT	365	return error;
	366	}
	367
8a25a2fd	368	struct device *get_cpu_device(unsigned cpu)
ad74557a	369	{
e37d05da MT	370	if (cpu < nr_cpu_ids && cpu_possible(cpu))
e37d05da MT	371	return per_cpu(cpu_sys_devices, cpu);
ad74557a AR	372	else
	373	return NULL;
	374	}
8a25a2fd KS	375	EXPORT_SYMBOL_GPL(get_cpu_device);
8a25a2fd KS	376
3d52943b SH	377	static void device_create_release(struct device *dev)
	378	{
	379	kfree(dev);
	380	}
	381
	382	static struct device *
	383	__cpu_device_create(struct device parent, void drvdata,
	384	const struct attribute_group **groups,
	385	const char *fmt, va_list args)
	386	{
	387	struct device *dev = NULL;
	388	int retval = -ENODEV;
	389
	390	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
	391	if (!dev) {
	392	retval = -ENOMEM;
	393	goto error;
	394	}
	395
	396	device_initialize(dev);
	397	dev->parent = parent;
	398	dev->groups = groups;
	399	dev->release = device_create_release;
	400	dev_set_drvdata(dev, drvdata);
	401
	402	retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
	403	if (retval)
	404	goto error;
	405
	406	retval = device_add(dev);
	407	if (retval)
	408	goto error;
	409
	410	return dev;
	411
	412	error:
	413	put_device(dev);
	414	return ERR_PTR(retval);
	415	}
	416
	417	struct device cpu_device_create(struct device parent, void *drvdata,
	418	const struct attribute_group **groups,
	419	const char *fmt, ...)
	420	{
	421	va_list vargs;
	422	struct device *dev;
	423
	424	va_start(vargs, fmt);
	425	dev = __cpu_device_create(parent, drvdata, groups, fmt, vargs);
	426	va_end(vargs);
	427	return dev;
	428	}
	429	EXPORT_SYMBOL_GPL(cpu_device_create);
	430
2b9c1f03	431	#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
67bad2fd	432	static DEVICE_ATTR(modalias, 0444, print_cpu_modalias, NULL);
fad12ac8 TR	433	#endif
fad12ac8 TR	434
8a25a2fd KS	435	static struct attribute *cpu_root_attrs[] = {
	436	#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
	437	&dev_attr_probe.attr,
	438	&dev_attr_release.attr,
	439	#endif
	440	&cpu_attrs[0].attr.attr,
	441	&cpu_attrs[1].attr.attr,
	442	&cpu_attrs[2].attr.attr,
	443	&dev_attr_kernel_max.attr,
	444	&dev_attr_offline.attr,
59f30abe	445	&dev_attr_isolated.attr,
2b9c1f03	446	#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
fad12ac8 TR	447	&dev_attr_modalias.attr,
fad12ac8 TR	448	#endif
8a25a2fd KS	449	NULL
	450	};
	451
	452	static struct attribute_group cpu_root_attr_group = {
	453	.attrs = cpu_root_attrs,
	454	};
	455
	456	static const struct attribute_group *cpu_root_attr_groups[] = {
	457	&cpu_root_attr_group,
	458	NULL,
	459	};
1da177e4	460
2987557f JT	461	bool cpu_is_hotpluggable(unsigned cpu)
2987557f JT	462	{
7affca35 LT	463	struct device *dev = get_cpu_device(cpu);
7affca35 LT	464	return dev && container_of(dev, struct cpu, dev)->hotpluggable;
2987557f JT	465	}
	466	EXPORT_SYMBOL_GPL(cpu_is_hotpluggable);
	467
9f13a1fd BH	468	#ifdef CONFIG_GENERIC_CPU_DEVICES
	469	static DEFINE_PER_CPU(struct cpu, cpu_devices);
	470	#endif
	471
	472	static void __init cpu_dev_register_generic(void)
	473	{
	474	#ifdef CONFIG_GENERIC_CPU_DEVICES
	475	int i;
	476
	477	for_each_possible_cpu(i) {
	478	if (register_cpu(&per_cpu(cpu_devices, i), i))
	479	panic("Failed to register CPU device");
	480	}
	481	#endif
	482	}
	483
024f7846	484	void __init cpu_dev_init(void)
1da177e4	485	{
024f7846 BH	486	if (subsys_system_register(&cpu_subsys, cpu_root_attr_groups))
024f7846 BH	487	panic("Failed to register CPU subsystem");
8a25a2fd	488
9f13a1fd	489	cpu_dev_register_generic();
1da177e4	490	}