Release 4.11 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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Rafael J. Wysocki
32
100.00%
1
100.00%
Total
32
100.00%
1
100.00%

#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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Yasuaki Ishimatsu
48
100.00%
1
100.00%
Total
48
100.00%
1
100.00%



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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Yasuaki Ishimatsu
40
43.96%
1
16.67%
Rusty Russell
34
37.36%
1
16.67%
Rafael J. Wysocki
11
12.09%
2
33.33%
Toshi Kani
4
4.40%
1
16.67%
Kay Sievers
2
2.20%
1
16.67%
Total
91
100.00%
6
100.00%



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

Contributors
Person
Tokens
Prop
Commits
CommitProp
Rusty Russell
9
47.37%
1
25.00%
Rafael J. Wysocki
8
42.11%
1
25.00%
Kay Sievers
1
5.26%
1
25.00%
Toshi Kani
1
5.26%
1
25.00%
Total
19
100.00%
4
100.00%



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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Len Brown
23
48.94%
1
20.00%
Ashok Raj
13
27.66%
1
20.00%
Kamezawa Hiroyuki
4
8.51%
1
20.00%
Mike Travis
4
8.51%
1
20.00%
Kay Sievers
3
6.38%
1
20.00%
Total
47
100.00%
5
100.00%

#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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Nathan Fontenot
25
43.86%
1
25.00%
Toshi Kani
25
43.86%
1
25.00%
Andi Kleen
4
7.02%
1
25.00%
Kay Sievers
3
5.26%
1
25.00%
Total
57
100.00%
4
100.00%



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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Toshi Kani
25
43.86%
1
25.00%
Nathan Fontenot
25
43.86%
1
25.00%
Andi Kleen
4
7.02%
1
25.00%
Kay Sievers
3
5.26%
1
25.00%
Total
57
100.00%
4
100.00%

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;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Vivek Goyal
73
90.12%
2
50.00%
Andi Kleen
4
4.94%
1
25.00%
Kay Sievers
4
4.94%
1
25.00%
Total
81
100.00%
4
100.00%

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;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Zhang Yanfei
39
97.50%
1
50.00%
Arnd Bergmann
1
2.50%
1
50.00%
Total
40
100.00%
2
100.00%

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);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Andi Kleen
24
51.06%
1
20.00%
Mike Travis
15
31.91%
1
20.00%
Sudeep Holla
4
8.51%
1
20.00%
Kay Sievers
3
6.38%
1
20.00%
Rusty Russell
1
2.13%
1
20.00%
Total
47
100.00%
5
100.00%


#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;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Mike Travis
34
82.93%
2
50.00%
Andi Kleen
4
9.76%
1
25.00%
Kay Sievers
3
7.32%
1
25.00%
Total
41
100.00%
4
100.00%

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;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Mike Travis
162
91.01%
1
20.00%
Tejun Heo
6
3.37%
1
20.00%
Andi Kleen
4
2.25%
1
20.00%
Kay Sievers
3
1.69%
1
20.00%
Jan Beulich
3
1.69%
1
20.00%
Total
178
100.00%
5
100.00%

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;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Rik Van Riel
50
100.00%
1
100.00%
Total
50
100.00%
1
100.00%

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;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Rik Van Riel
50
100.00%
1
100.00%
Total
50
100.00%
1
100.00%

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.
         */
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Greg Kroah-Hartman
11
91.67%
1
50.00%
Ralf Bächle
1
8.33%
1
50.00%
Total
12
100.00%
2
100.00%

#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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Ard Biesheuvel
108
100.00%
1
100.00%
Total
108
100.00%
1
100.00%



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;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Ard Biesheuvel
59
100.00%
1
100.00%
Total
59
100.00%
1
100.00%

#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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
40
20.94%
4
16.67%
Greg Kroah-Hartman
26
13.61%
3
12.50%
Igor Mammedov
22
11.52%
2
8.33%
Alex Shi
14
7.33%
2
8.33%
Thomas Renninger
13
6.81%
1
4.17%
Sudeep KarkadaNagesha
13
6.81%
1
4.17%
Ashok Raj
13
6.81%
2
8.33%
Toshi Kani
12
6.28%
1
4.17%
Rafael J. Wysocki
11
5.76%
1
4.17%
Kamezawa Hiroyuki
10
5.24%
1
4.17%
Kay Sievers
5
2.62%
1
4.17%
Rusty Russell
5
2.62%
1
4.17%
Mike Travis
4
2.09%
1
4.17%
Ard Biesheuvel
2
1.05%
2
8.33%
Suresh B. Siddha
1
0.52%
1
4.17%
Total
191
100.00%
24
100.00%



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;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Ashok Raj
20
60.61%
1
25.00%
Mike Travis
10
30.30%
1
25.00%
Kay Sievers
2
6.06%
1
25.00%
Andrew Morton
1
3.03%
1
25.00%
Total
33
100.00%
4
100.00%


EXPORT_SYMBOL_GPL(get_cpu_device);



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

Contributors
Person
Tokens
Prop
Commits
CommitProp
Sudeep Holla
16
100.00%
1
100.00%
Total
16
100.00%
1
100.00%


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);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Sudeep Holla
154
100.00%
1
100.00%
Total
154
100.00%
1
100.00%



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;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Sudeep Holla
68
100.00%
1
100.00%
Total
68
100.00%
1
100.00%


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;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Josh Triplett
30
90.91%
1
50.00%
Linus Torvalds
3
9.09%
1
50.00%
Total
33
100.00%
2
100.00%


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
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Ben Hutchings
43
100.00%
1
100.00%
Total
43
100.00%
1
100.00%



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();
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Ben Hutchings
11
42.31%
2
33.33%
Patrick Mochel
10
38.46%
3
50.00%
Kay Sievers
5
19.23%
1
16.67%
Total
26
100.00%
6
100.00%

Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Mike Travis
279
13.19%
4
6.15%
Sudeep Holla
247
11.68%
2
3.08%
Ard Biesheuvel
180
8.51%
2
3.08%
Rik Van Riel
147
6.95%
2
3.08%
Andi Kleen
129
6.10%
5
7.69%
Rafael J. Wysocki
107
5.06%
3
4.62%
Igor Mammedov
95
4.49%
2
3.08%
Kay Sievers
95
4.49%
1
1.54%
Vivek Goyal
92
4.35%
2
3.08%
Yasuaki Ishimatsu
88
4.16%
1
1.54%
Nathan Fontenot
78
3.69%
1
1.54%
Ben Hutchings
74
3.50%
2
3.08%
Toshi Kani
67
3.17%
3
4.62%
Rusty Russell
58
2.74%
2
3.08%
Ashok Raj
52
2.46%
2
3.08%
Zhang Yanfei
51
2.41%
1
1.54%
Andrew Morton
43
2.03%
5
7.69%
Thomas Renninger
40
1.89%
1
1.54%
Greg Kroah-Hartman
37
1.75%
3
4.62%
Josh Triplett
35
1.65%
1
1.54%
Len Brown
23
1.09%
1
1.54%
Patrick Mochel
20
0.95%
4
6.15%
Kamezawa Hiroyuki
17
0.80%
1
1.54%
Alex Shi
17
0.80%
2
3.08%
Sudeep KarkadaNagesha
16
0.76%
1
1.54%
Tejun Heo
9
0.43%
2
3.08%
Linus Torvalds
3
0.14%
1
1.54%
Rasmus Villemoes
3
0.14%
1
1.54%
Al Viro
3
0.14%
1
1.54%
Jan Beulich
3
0.14%
1
1.54%
Ben Dooks
3
0.14%
1
1.54%
Suresh B. Siddha
1
0.05%
1
1.54%
Ralf Bächle
1
0.05%
1
1.54%
Robert P. J. Day
1
0.05%
1
1.54%
Arnd Bergmann
1
0.05%
1
1.54%
Total
2115
100.00%
65
100.00%
Directory: drivers/base

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.