[deliverable/linux.git] / drivers / base / cpu.c

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

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

#include "base.h"

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

static DEFINE_PER_CPU(struct sys_device *, cpu_sys_devices);

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

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

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

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

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

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

	unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));

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

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

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

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

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

int __init cpu_probe_release_init(void)
{
	int rc;

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

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

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

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

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

	cpunum = cpu->sysdev.id;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	error = sysdev_register(&cpu->sysdev);

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

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

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

int __init cpu_dev_init(void)
{
	int err;

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

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

	return err;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* drivers/base/cpu.c - basic CPU class support
	3	*/
	4
	5	#include <linux/sysdev.h>
	6	#include <linux/module.h>
	7	#include <linux/init.h>
f6a57033	8	#include <linux/sched.h>
1da177e4 LT	9	#include <linux/cpu.h>
	10	#include <linux/topology.h>
	11	#include <linux/device.h>
76b67ed9	12	#include <linux/node.h>
1da177e4	13
a1bdc7aa	14	#include "base.h"
1da177e4 LT	15
1da177e4 LT	16	struct sysdev_class cpu_sysdev_class = {
af5ca3f4	17	.name = "cpu",
1da177e4 LT	18	};
	19	EXPORT_SYMBOL(cpu_sysdev_class);
	20
e37d05da	21	static DEFINE_PER_CPU(struct sys_device *, cpu_sys_devices);
ad74557a	22
1da177e4	23	#ifdef CONFIG_HOTPLUG_CPU
4a0b2b4d AK	24	static ssize_t show_online(struct sys_device dev, struct sysdev_attribute attr,
4a0b2b4d AK	25	char *buf)
1da177e4 LT	26	{
	27	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
	28
	29	return sprintf(buf, "%u\n", !!cpu_online(cpu->sysdev.id));
	30	}
	31
4a0b2b4d AK	32	static ssize_t __ref store_online(struct sys_device dev, struct sysdev_attribute attr,
4a0b2b4d AK	33	const char *buf, size_t count)
1da177e4 LT	34	{
	35	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
	36	ssize_t ret;
	37
51badebd	38	cpu_hotplug_driver_lock();
1da177e4 LT	39	switch (buf[0]) {
	40	case '0':
	41	ret = cpu_down(cpu->sysdev.id);
	42	if (!ret)
312c004d	43	kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
1da177e4 LT	44	break;
1da177e4 LT	45	case '1':
34f361ad	46	ret = cpu_up(cpu->sysdev.id);
fb69c390	47	if (!ret)
312c004d	48	kobject_uevent(&dev->kobj, KOBJ_ONLINE);
1da177e4 LT	49	break;
	50	default:
	51	ret = -EINVAL;
	52	}
51badebd	53	cpu_hotplug_driver_unlock();
1da177e4 LT	54
	55	if (ret >= 0)
	56	ret = count;
	57	return ret;
	58	}
9eb3ff40	59	static SYSDEV_ATTR(online, 0644, show_online, store_online);
1da177e4	60
6c847402	61	static void __cpuinit register_cpu_control(struct cpu *cpu)
1da177e4 LT	62	{
	63	sysdev_create_file(&cpu->sysdev, &attr_online);
	64	}
76b67ed9	65	void unregister_cpu(struct cpu *cpu)
1da177e4	66	{
ad74557a	67	int logical_cpu = cpu->sysdev.id;
1da177e4	68
76b67ed9 KH	69	unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));
76b67ed9 KH	70
1da177e4 LT	71	sysdev_remove_file(&cpu->sysdev, &attr_online);
	72
	73	sysdev_unregister(&cpu->sysdev);
e37d05da	74	per_cpu(cpu_sys_devices, logical_cpu) = NULL;
1da177e4 LT	75	return;
1da177e4 LT	76	}
12633e80 NF	77
	78	#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
	79	static ssize_t cpu_probe_store(struct class class, const char buf,
	80	size_t count)
	81	{
	82	return arch_cpu_probe(buf, count);
	83	}
	84
	85	static ssize_t cpu_release_store(struct class class, const char buf,
	86	size_t count)
	87	{
	88	return arch_cpu_release(buf, count);
	89	}
	90
	91	static CLASS_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
	92	static CLASS_ATTR(release, S_IWUSR, NULL, cpu_release_store);
	93
	94	int __init cpu_probe_release_init(void)
	95	{
	96	int rc;
	97
	98	rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
	99	&class_attr_probe.attr);
	100	if (!rc)
	101	rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
	102	&class_attr_release.attr);
	103
	104	return rc;
	105	}
	106	device_initcall(cpu_probe_release_init);
	107	#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
	108
1da177e4 LT	109	#else /* ... !CONFIG_HOTPLUG_CPU */
	110	static inline void register_cpu_control(struct cpu *cpu)
	111	{
	112	}
	113	#endif /* CONFIG_HOTPLUG_CPU */
	114
51be5606 VG	115	#ifdef CONFIG_KEXEC
	116	#include <linux/kexec.h>
	117
4a0b2b4d AK	118	static ssize_t show_crash_notes(struct sys_device dev, struct sysdev_attribute attr,
4a0b2b4d AK	119	char *buf)
51be5606 VG	120	{
	121	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
	122	ssize_t rc;
	123	unsigned long long addr;
	124	int cpunum;
	125
	126	cpunum = cpu->sysdev.id;
	127
	128	/*
	129	* Might be reading other cpu's data based on which cpu read thread
	130	* has been scheduled. But cpu data (memory) is allocated once during
	131	* boot up and this data does not change there after. Hence this
	132	* operation should be safe. No locking required.
	133	*/
3b034b0d	134	addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpunum));
51be5606	135	rc = sprintf(buf, "%Lx\n", addr);
51be5606 VG	136	return rc;
	137	}
	138	static SYSDEV_ATTR(crash_notes, 0400, show_crash_notes, NULL);
	139	#endif
	140
9d1fe323 MT	141	/*
	142	* Print cpu online, possible, present, and system maps
	143	*/
f7df8ed1	144	static ssize_t print_cpus_map(char buf, const struct cpumask map)
9d1fe323	145	{
29c0177e	146	int n = cpulist_scnprintf(buf, PAGE_SIZE-2, map);
9d1fe323 MT	147
	148	buf[n++] = '\n';
	149	buf[n] = '\0';
	150	return n;
	151	}
	152
	153	#define print_cpus_func(type) \
	154	static ssize_t print_cpus_##type(struct sysdev_class class, char buf) \
	155	{ \
aa85ea5b	156	return print_cpus_map(buf, cpu_##type##_mask); \
9d1fe323	157	} \
143aa5c5	158	static struct sysdev_class_attribute attr_##type##_map = \
9d1fe323 MT	159	_SYSDEV_CLASS_ATTR(type, 0444, print_cpus_##type, NULL)
	160
	161	print_cpus_func(online);
	162	print_cpus_func(possible);
	163	print_cpus_func(present);
	164
e057d7ae MT	165	/*
	166	* Print values for NR_CPUS and offlined cpus
	167	*/
	168	static ssize_t print_cpus_kernel_max(struct sysdev_class class, char buf)
	169	{
8fd2d2d5	170	int n = snprintf(buf, PAGE_SIZE-2, "%d\n", NR_CPUS - 1);
e057d7ae MT	171	return n;
	172	}
	173	static SYSDEV_CLASS_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL);
	174
	175	/* arch-optional setting to enable display of offline cpus >= nr_cpu_ids */
	176	unsigned int total_cpus;
	177
	178	static ssize_t print_cpus_offline(struct sysdev_class class, char buf)
	179	{
	180	int n = 0, len = PAGE_SIZE-2;
	181	cpumask_var_t offline;
	182
	183	/* display offline cpus < nr_cpu_ids */
	184	if (!alloc_cpumask_var(&offline, GFP_KERNEL))
	185	return -ENOMEM;
	186	cpumask_complement(offline, cpu_online_mask);
	187	n = cpulist_scnprintf(buf, len, offline);
	188	free_cpumask_var(offline);
	189
	190	/* display offline cpus >= nr_cpu_ids */
	191	if (total_cpus && nr_cpu_ids < total_cpus) {
	192	if (n && n < len)
	193	buf[n++] = ',';
	194
	195	if (nr_cpu_ids == total_cpus-1)
	196	n += snprintf(&buf[n], len - n, "%d", nr_cpu_ids);
	197	else
	198	n += snprintf(&buf[n], len - n, "%d-%d",
	199	nr_cpu_ids, total_cpus-1);
	200	}
	201
	202	n += snprintf(&buf[n], len - n, "\n");
	203	return n;
	204	}
	205	static SYSDEV_CLASS_ATTR(offline, 0444, print_cpus_offline, NULL);
	206
143aa5c5	207	static struct sysdev_class_attribute *cpu_state_attr[] = {
9d1fe323 MT	208	&attr_online_map,
	209	&attr_possible_map,
	210	&attr_present_map,
e057d7ae MT	211	&attr_kernel_max,
e057d7ae MT	212	&attr_offline,
9d1fe323 MT	213	};
	214
	215	static int cpu_states_init(void)
	216	{
	217	int i;
	218	int err = 0;
	219
	220	for (i = 0; i < ARRAY_SIZE(cpu_state_attr); i++) {
	221	int ret;
	222	ret = sysdev_class_create_file(&cpu_sysdev_class,
	223	cpu_state_attr[i]);
	224	if (!err)
	225	err = ret;
	226	}
	227	return err;
	228	}
	229
1da177e4	230	/*
405ae7d3	231	* register_cpu - Setup a sysfs device for a CPU.
72486f1f SS	232	* @cpu - cpu->hotpluggable field set to 1 will generate a control file in
72486f1f SS	233	* sysfs for this CPU.
1da177e4 LT	234	* @num - CPU number to use when creating the device.
	235	*
	236	* Initialize and register the CPU device.
	237	*/
33b5f31b	238	int __cpuinit register_cpu(struct cpu *cpu, int num)
1da177e4 LT	239	{
1da177e4 LT	240	int error;
1da177e4 LT	241	cpu->node_id = cpu_to_node(num);
	242	cpu->sysdev.id = num;
	243	cpu->sysdev.cls = &cpu_sysdev_class;
	244
	245	error = sysdev_register(&cpu->sysdev);
76b67ed9	246
72486f1f	247	if (!error && cpu->hotpluggable)
1da177e4	248	register_cpu_control(cpu);
ad74557a	249	if (!error)
e37d05da	250	per_cpu(cpu_sys_devices, num) = &cpu->sysdev;
76b67ed9 KH	251	if (!error)
76b67ed9 KH	252	register_cpu_under_node(num, cpu_to_node(num));
51be5606 VG	253
	254	#ifdef CONFIG_KEXEC
	255	if (!error)
	256	error = sysdev_create_file(&cpu->sysdev, &attr_crash_notes);
	257	#endif
1da177e4 LT	258	return error;
	259	}
	260
a29d642a	261	struct sys_device *get_cpu_sysdev(unsigned cpu)
ad74557a	262	{
e37d05da MT	263	if (cpu < nr_cpu_ids && cpu_possible(cpu))
e37d05da MT	264	return per_cpu(cpu_sys_devices, cpu);
ad74557a AR	265	else
	266	return NULL;
	267	}
	268	EXPORT_SYMBOL_GPL(get_cpu_sysdev);
1da177e4 LT	269
	270	int __init cpu_dev_init(void)
	271	{
5c45bf27 SS	272	int err;
	273
	274	err = sysdev_class_register(&cpu_sysdev_class);
9d1fe323 MT	275	if (!err)
	276	err = cpu_states_init();
	277
5c45bf27 SS	278	#if defined(CONFIG_SCHED_MC) \|\| defined(CONFIG_SCHED_SMT)
	279	if (!err)
	280	err = sched_create_sysfs_power_savings_entries(&cpu_sysdev_class);
	281	#endif
	282
	283	return err;
1da177e4	284	}