[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 <linux/cpufeature.h>
#include <linux/tick.h>
#include <linux/pm_qos.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 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 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);

#ifdef CONFIG_NO_HZ_FULL
static ssize_t print_cpus_nohz_full(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(tick_nohz_full_mask));

	return n;
}
static DEVICE_ATTR(nohz_full, 0444, print_cpus_nohz_full, NULL);
#endif

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)
		return error;

	per_cpu(cpu_sys_devices, num) = &cpu->dev;
	register_cpu_under_node(num, cpu_to_node(num));
	dev_pm_qos_expose_latency_limit(&cpu->dev, 0);

	return 0;
}

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_NO_HZ_FULL
	&dev_attr_nohz_full.attr,
#endif
#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>
6570a9a1	19	#include <linux/tick.h>
37efa4b4	20	#include <linux/pm_qos.h>
1da177e4	21
a1bdc7aa	22	#include "base.h"
1da177e4	23
8a25a2fd	24	static DEFINE_PER_CPU(struct device *, cpu_sys_devices);
ad74557a	25
ac212b69 RW	26	static int cpu_subsys_match(struct device dev, struct device_driver drv)
	27	{
	28	/* ACPI style match is the only one that may succeed. */
	29	if (acpi_driver_match_device(dev, drv))
	30	return 1;
	31
	32	return 0;
	33	}
	34
1da177e4	35	#ifdef CONFIG_HOTPLUG_CPU
34640468 YI	36	static void change_cpu_under_node(struct cpu *cpu,
	37	unsigned int from_nid, unsigned int to_nid)
	38	{
	39	int cpuid = cpu->dev.id;
	40	unregister_cpu_under_node(cpuid, from_nid);
	41	register_cpu_under_node(cpuid, to_nid);
	42	cpu->node_id = to_nid;
	43	}
	44
eda5867b	45	static int cpu_subsys_online(struct device *dev)
1da177e4	46	{
8a25a2fd	47	struct cpu *cpu = container_of(dev, struct cpu, dev);
0902a904 RW	48	int cpuid = dev->id;
0902a904 RW	49	int from_nid, to_nid;
6dedcca6	50	int ret;
1da177e4	51
0902a904	52	from_nid = cpu_to_node(cpuid);
c7991b0b	53	if (from_nid == NUMA_NO_NODE)
6dedcca6	54	return -ENODEV;
c7991b0b	55
0902a904 RW	56	ret = cpu_up(cpuid);
	57	/*
	58	* When hot adding memory to memoryless node and enabling a cpu
	59	* on the node, node number of the cpu may internally change.
	60	*/
	61	to_nid = cpu_to_node(cpuid);
	62	if (from_nid != to_nid)
	63	change_cpu_under_node(cpu, from_nid, to_nid);
1da177e4	64
0902a904	65	return ret;
1da177e4 LT	66	}
1da177e4 LT	67
0902a904	68	static int cpu_subsys_offline(struct device *dev)
1da177e4	69	{
6dedcca6	70	return cpu_down(dev->id);
1da177e4	71	}
1c4e2d70	72
76b67ed9	73	void unregister_cpu(struct cpu *cpu)
1da177e4	74	{
8a25a2fd	75	int logical_cpu = cpu->dev.id;
1da177e4	76
76b67ed9 KH	77	unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));
76b67ed9 KH	78
8a25a2fd	79	device_unregister(&cpu->dev);
e37d05da	80	per_cpu(cpu_sys_devices, logical_cpu) = NULL;
1da177e4 LT	81	return;
1da177e4 LT	82	}
12633e80 NF	83
12633e80 NF	84	#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
8a25a2fd KS	85	static ssize_t cpu_probe_store(struct device *dev,
8a25a2fd KS	86	struct device_attribute *attr,
67fc233f	87	const char *buf,
12633e80 NF	88	size_t count)
12633e80 NF	89	{
574b851e TK	90	ssize_t cnt;
	91	int ret;
	92
	93	ret = lock_device_hotplug_sysfs();
	94	if (ret)
	95	return ret;
	96
	97	cnt = arch_cpu_probe(buf, count);
	98
	99	unlock_device_hotplug();
	100	return cnt;
12633e80 NF	101	}
12633e80 NF	102
8a25a2fd KS	103	static ssize_t cpu_release_store(struct device *dev,
8a25a2fd KS	104	struct device_attribute *attr,
67fc233f	105	const char *buf,
12633e80 NF	106	size_t count)
12633e80 NF	107	{
574b851e TK	108	ssize_t cnt;
	109	int ret;
	110
	111	ret = lock_device_hotplug_sysfs();
	112	if (ret)
	113	return ret;
	114
	115	cnt = arch_cpu_release(buf, count);
	116
	117	unlock_device_hotplug();
	118	return cnt;
12633e80 NF	119	}
12633e80 NF	120
8a25a2fd KS	121	static DEVICE_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
8a25a2fd KS	122	static DEVICE_ATTR(release, S_IWUSR, NULL, cpu_release_store);
12633e80	123	#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
1da177e4 LT	124	#endif /* CONFIG_HOTPLUG_CPU */
1da177e4 LT	125
0902a904 RW	126	struct bus_type cpu_subsys = {
	127	.name = "cpu",
	128	.dev_name = "cpu",
ac212b69	129	.match = cpu_subsys_match,
0902a904 RW	130	#ifdef CONFIG_HOTPLUG_CPU
	131	.online = cpu_subsys_online,
	132	.offline = cpu_subsys_offline,
	133	#endif
	134	};
	135	EXPORT_SYMBOL_GPL(cpu_subsys);
	136
51be5606 VG	137	#ifdef CONFIG_KEXEC
	138	#include <linux/kexec.h>
	139
8a25a2fd	140	static ssize_t show_crash_notes(struct device dev, struct device_attribute attr,
4a0b2b4d	141	char *buf)
51be5606	142	{
8a25a2fd	143	struct cpu *cpu = container_of(dev, struct cpu, dev);
51be5606 VG	144	ssize_t rc;
	145	unsigned long long addr;
	146	int cpunum;
	147
8a25a2fd	148	cpunum = cpu->dev.id;
51be5606 VG	149
	150	/*
	151	* Might be reading other cpu's data based on which cpu read thread
	152	* has been scheduled. But cpu data (memory) is allocated once during
	153	* boot up and this data does not change there after. Hence this
	154	* operation should be safe. No locking required.
	155	*/
3b034b0d	156	addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpunum));
51be5606	157	rc = sprintf(buf, "%Lx\n", addr);
51be5606 VG	158	return rc;
51be5606 VG	159	}
8a25a2fd	160	static DEVICE_ATTR(crash_notes, 0400, show_crash_notes, NULL);
eca4549f ZY	161
	162	static ssize_t show_crash_notes_size(struct device *dev,
	163	struct device_attribute *attr,
	164	char *buf)
	165	{
	166	ssize_t rc;
	167
bcfb87fb	168	rc = sprintf(buf, "%zu\n", sizeof(note_buf_t));
eca4549f ZY	169	return rc;
	170	}
	171	static DEVICE_ATTR(crash_notes_size, 0400, show_crash_notes_size, NULL);
c055da9f IM	172
	173	static struct attribute *crash_note_cpu_attrs[] = {
	174	&dev_attr_crash_notes.attr,
	175	&dev_attr_crash_notes_size.attr,
	176	NULL
	177	};
	178
	179	static struct attribute_group crash_note_cpu_attr_group = {
	180	.attrs = crash_note_cpu_attrs,
	181	};
	182	#endif
	183
	184	static const struct attribute_group *common_cpu_attr_groups[] = {
	185	#ifdef CONFIG_KEXEC
	186	&crash_note_cpu_attr_group,
51be5606	187	#endif
c055da9f IM	188	NULL
c055da9f IM	189	};
51be5606	190
1c4e2d70 IM	191	static const struct attribute_group *hotplugable_cpu_attr_groups[] = {
	192	#ifdef CONFIG_KEXEC
	193	&crash_note_cpu_attr_group,
1c4e2d70 IM	194	#endif
	195	NULL
	196	};
	197
9d1fe323 MT	198	/*
	199	* Print cpu online, possible, present, and system maps
	200	*/
265d2e2e AK	201
265d2e2e AK	202	struct cpu_attr {
8a25a2fd	203	struct device_attribute attr;
848e2391	204	const struct cpumask *const map;
265d2e2e AK	205	};
265d2e2e AK	206
8a25a2fd KS	207	static ssize_t show_cpus_attr(struct device *dev,
8a25a2fd KS	208	struct device_attribute *attr,
265d2e2e	209	char *buf)
9d1fe323	210	{
265d2e2e	211	struct cpu_attr *ca = container_of(attr, struct cpu_attr, attr);
9d1fe323	212
848e2391	213	return cpumap_print_to_pagebuf(true, buf, ca->map);
9d1fe323 MT	214	}
9d1fe323 MT	215
8a25a2fd KS	216	#define _CPU_ATTR(name, map) \
8a25a2fd KS	217	{ __ATTR(name, 0444, show_cpus_attr, NULL), map }
9d1fe323	218
8a25a2fd	219	/* Keep in sync with cpu_subsys_attrs */
265d2e2e	220	static struct cpu_attr cpu_attrs[] = {
848e2391 RV	221	_CPU_ATTR(online, &__cpu_online_mask),
	222	_CPU_ATTR(possible, &__cpu_possible_mask),
	223	_CPU_ATTR(present, &__cpu_present_mask),
265d2e2e	224	};
9d1fe323	225
e057d7ae MT	226	/*
	227	* Print values for NR_CPUS and offlined cpus
	228	*/
8a25a2fd KS	229	static ssize_t print_cpus_kernel_max(struct device *dev,
8a25a2fd KS	230	struct device_attribute attr, char buf)
e057d7ae	231	{
8fd2d2d5	232	int n = snprintf(buf, PAGE_SIZE-2, "%d\n", NR_CPUS - 1);
e057d7ae MT	233	return n;
e057d7ae MT	234	}
8a25a2fd	235	static DEVICE_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL);
e057d7ae MT	236
	237	/* arch-optional setting to enable display of offline cpus >= nr_cpu_ids */
	238	unsigned int total_cpus;
	239
8a25a2fd KS	240	static ssize_t print_cpus_offline(struct device *dev,
8a25a2fd KS	241	struct device_attribute attr, char buf)
e057d7ae MT	242	{
	243	int n = 0, len = PAGE_SIZE-2;
	244	cpumask_var_t offline;
	245
	246	/* display offline cpus < nr_cpu_ids */
	247	if (!alloc_cpumask_var(&offline, GFP_KERNEL))
	248	return -ENOMEM;
cdc6e3d3	249	cpumask_andnot(offline, cpu_possible_mask, cpu_online_mask);
f799b1a7	250	n = scnprintf(buf, len, "%*pbl", cpumask_pr_args(offline));
e057d7ae MT	251	free_cpumask_var(offline);
	252
	253	/* display offline cpus >= nr_cpu_ids */
	254	if (total_cpus && nr_cpu_ids < total_cpus) {
	255	if (n && n < len)
	256	buf[n++] = ',';
	257
	258	if (nr_cpu_ids == total_cpus-1)
	259	n += snprintf(&buf[n], len - n, "%d", nr_cpu_ids);
	260	else
	261	n += snprintf(&buf[n], len - n, "%d-%d",
	262	nr_cpu_ids, total_cpus-1);
	263	}
	264
	265	n += snprintf(&buf[n], len - n, "\n");
	266	return n;
	267	}
8a25a2fd	268	static DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL);
e057d7ae	269
59f30abe RR	270	static ssize_t print_cpus_isolated(struct device *dev,
	271	struct device_attribute attr, char buf)
	272	{
	273	int n = 0, len = PAGE_SIZE-2;
	274
	275	n = scnprintf(buf, len, "%*pbl\n", cpumask_pr_args(cpu_isolated_map));
	276
	277	return n;
	278	}
	279	static DEVICE_ATTR(isolated, 0444, print_cpus_isolated, NULL);
	280
6570a9a1 RR	281	#ifdef CONFIG_NO_HZ_FULL
	282	static ssize_t print_cpus_nohz_full(struct device *dev,
	283	struct device_attribute attr, char buf)
	284	{
	285	int n = 0, len = PAGE_SIZE-2;
	286
	287	n = scnprintf(buf, len, "%*pbl\n", cpumask_pr_args(tick_nohz_full_mask));
	288
	289	return n;
	290	}
	291	static DEVICE_ATTR(nohz_full, 0444, print_cpus_nohz_full, NULL);
	292	#endif
	293
2885e25c GKH	294	static void cpu_device_release(struct device *dev)
	295	{
	296	/*
	297	* This is an empty function to prevent the driver core from spitting a
	298	* warning at us. Yes, I know this is directly opposite of what the
	299	* documentation for the driver core and kobjects say, and the author
	300	* of this code has already been publically ridiculed for doing
	301	* something as foolish as this. However, at this point in time, it is
	302	* the only way to handle the issue of statically allocated cpu
	303	* devices. The different architectures will have their cpu device
	304	* code reworked to properly handle this in the near future, so this
	305	* function will then be changed to correctly free up the memory held
	306	* by the cpu device.
	307	*
	308	* Never copy this way of doing things, or you too will be made fun of
30a4840a	309	* on the linux-kernel list, you have been warned.
2885e25c GKH	310	*/
	311	}
	312
67bad2fd AB	313	#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
	314	static ssize_t print_cpu_modalias(struct device *dev,
	315	struct device_attribute *attr,
	316	char *buf)
	317	{
	318	ssize_t n;
	319	u32 i;
	320
	321	n = sprintf(buf, "cpu:type:" CPU_FEATURE_TYPEFMT ":feature:",
	322	CPU_FEATURE_TYPEVAL);
	323
	324	for (i = 0; i < MAX_CPU_FEATURES; i++)
	325	if (cpu_have_feature(i)) {
	326	if (PAGE_SIZE < n + sizeof(",XXXX\n")) {
	327	WARN(1, "CPU features overflow page\n");
	328	break;
	329	}
	330	n += sprintf(&buf[n], ",%04X", i);
	331	}
	332	buf[n++] = '\n';
	333	return n;
	334	}
67bad2fd AB	335
	336	static int cpu_uevent(struct device dev, struct kobj_uevent_env env)
	337	{
	338	char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
	339	if (buf) {
	340	print_cpu_modalias(NULL, NULL, buf);
	341	add_uevent_var(env, "MODALIAS=%s", buf);
	342	kfree(buf);
	343	}
	344	return 0;
	345	}
	346	#endif
	347
1da177e4	348	/*
405ae7d3	349	* register_cpu - Setup a sysfs device for a CPU.
72486f1f SS	350	* @cpu - cpu->hotpluggable field set to 1 will generate a control file in
72486f1f SS	351	* sysfs for this CPU.
1da177e4 LT	352	* @num - CPU number to use when creating the device.
	353	*
	354	* Initialize and register the CPU device.
	355	*/
a83048eb	356	int register_cpu(struct cpu *cpu, int num)
1da177e4 LT	357	{
1da177e4 LT	358	int error;
76b67ed9	359
8a25a2fd	360	cpu->node_id = cpu_to_node(num);
29bb5d4f	361	memset(&cpu->dev, 0x00, sizeof(struct device));
8a25a2fd KS	362	cpu->dev.id = num;
8a25a2fd KS	363	cpu->dev.bus = &cpu_subsys;
2885e25c	364	cpu->dev.release = cpu_device_release;
0902a904	365	cpu->dev.offline_disabled = !cpu->hotpluggable;
1001b4d4	366	cpu->dev.offline = !cpu_online(num);
f86e4718	367	cpu->dev.of_node = of_get_cpu_node(num, NULL);
2b9c1f03	368	#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
67bad2fd	369	cpu->dev.bus->uevent = cpu_uevent;
fad12ac8	370	#endif
c055da9f	371	cpu->dev.groups = common_cpu_attr_groups;
1c4e2d70 IM	372	if (cpu->hotpluggable)
1c4e2d70 IM	373	cpu->dev.groups = hotplugable_cpu_attr_groups;
8a25a2fd	374	error = device_register(&cpu->dev);
59fffa34 AS	375	if (error)
59fffa34 AS	376	return error;
51be5606	377
59fffa34 AS	378	per_cpu(cpu_sys_devices, num) = &cpu->dev;
59fffa34 AS	379	register_cpu_under_node(num, cpu_to_node(num));
37efa4b4	380	dev_pm_qos_expose_latency_limit(&cpu->dev, 0);
59fffa34 AS	381
59fffa34 AS	382	return 0;
1da177e4 LT	383	}
1da177e4 LT	384
8a25a2fd	385	struct device *get_cpu_device(unsigned cpu)
ad74557a	386	{
e37d05da MT	387	if (cpu < nr_cpu_ids && cpu_possible(cpu))
e37d05da MT	388	return per_cpu(cpu_sys_devices, cpu);
ad74557a AR	389	else
	390	return NULL;
	391	}
8a25a2fd KS	392	EXPORT_SYMBOL_GPL(get_cpu_device);
8a25a2fd KS	393
3d52943b SH	394	static void device_create_release(struct device *dev)
	395	{
	396	kfree(dev);
	397	}
	398
	399	static struct device *
	400	__cpu_device_create(struct device parent, void drvdata,
	401	const struct attribute_group **groups,
	402	const char *fmt, va_list args)
	403	{
	404	struct device *dev = NULL;
	405	int retval = -ENODEV;
	406
	407	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
	408	if (!dev) {
	409	retval = -ENOMEM;
	410	goto error;
	411	}
	412
	413	device_initialize(dev);
	414	dev->parent = parent;
	415	dev->groups = groups;
	416	dev->release = device_create_release;
	417	dev_set_drvdata(dev, drvdata);
	418
	419	retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
	420	if (retval)
	421	goto error;
	422
	423	retval = device_add(dev);
	424	if (retval)
	425	goto error;
	426
	427	return dev;
	428
	429	error:
	430	put_device(dev);
	431	return ERR_PTR(retval);
	432	}
	433
	434	struct device cpu_device_create(struct device parent, void *drvdata,
	435	const struct attribute_group **groups,
	436	const char *fmt, ...)
	437	{
	438	va_list vargs;
	439	struct device *dev;
	440
	441	va_start(vargs, fmt);
	442	dev = __cpu_device_create(parent, drvdata, groups, fmt, vargs);
	443	va_end(vargs);
	444	return dev;
	445	}
	446	EXPORT_SYMBOL_GPL(cpu_device_create);
	447
2b9c1f03	448	#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
67bad2fd	449	static DEVICE_ATTR(modalias, 0444, print_cpu_modalias, NULL);
fad12ac8 TR	450	#endif
fad12ac8 TR	451
8a25a2fd KS	452	static struct attribute *cpu_root_attrs[] = {
	453	#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
	454	&dev_attr_probe.attr,
	455	&dev_attr_release.attr,
	456	#endif
	457	&cpu_attrs[0].attr.attr,
	458	&cpu_attrs[1].attr.attr,
	459	&cpu_attrs[2].attr.attr,
	460	&dev_attr_kernel_max.attr,
	461	&dev_attr_offline.attr,
59f30abe	462	&dev_attr_isolated.attr,
6570a9a1 RR	463	#ifdef CONFIG_NO_HZ_FULL
	464	&dev_attr_nohz_full.attr,
	465	#endif
2b9c1f03	466	#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
fad12ac8 TR	467	&dev_attr_modalias.attr,
fad12ac8 TR	468	#endif
8a25a2fd KS	469	NULL
	470	};
	471
	472	static struct attribute_group cpu_root_attr_group = {
	473	.attrs = cpu_root_attrs,
	474	};
	475
	476	static const struct attribute_group *cpu_root_attr_groups[] = {
	477	&cpu_root_attr_group,
	478	NULL,
	479	};
1da177e4	480
2987557f JT	481	bool cpu_is_hotpluggable(unsigned cpu)
2987557f JT	482	{
7affca35 LT	483	struct device *dev = get_cpu_device(cpu);
7affca35 LT	484	return dev && container_of(dev, struct cpu, dev)->hotpluggable;
2987557f JT	485	}
	486	EXPORT_SYMBOL_GPL(cpu_is_hotpluggable);
	487
9f13a1fd BH	488	#ifdef CONFIG_GENERIC_CPU_DEVICES
	489	static DEFINE_PER_CPU(struct cpu, cpu_devices);
	490	#endif
	491
	492	static void __init cpu_dev_register_generic(void)
	493	{
	494	#ifdef CONFIG_GENERIC_CPU_DEVICES
	495	int i;
	496
	497	for_each_possible_cpu(i) {
	498	if (register_cpu(&per_cpu(cpu_devices, i), i))
	499	panic("Failed to register CPU device");
	500	}
	501	#endif
	502	}
	503
024f7846	504	void __init cpu_dev_init(void)
1da177e4	505	{
024f7846 BH	506	if (subsys_system_register(&cpu_subsys, cpu_root_attr_groups))
024f7846 BH	507	panic("Failed to register CPU subsystem");
8a25a2fd	508
9f13a1fd	509	cpu_dev_register_generic();
1da177e4	510	}