Contributors: 58
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Mike Travis |
265 |
10.18% |
4 |
3.64% |
| Sudeep Holla |
256 |
9.84% |
4 |
3.64% |
| Kay Sievers |
181 |
6.96% |
3 |
2.73% |
| Andi Kleen |
175 |
6.73% |
7 |
6.36% |
| Thomas Gleixner |
138 |
5.30% |
2 |
1.82% |
| Rusty Russell |
134 |
5.15% |
3 |
2.73% |
| Ard Biesheuvel |
127 |
4.88% |
2 |
1.82% |
| Igor Mammedov |
87 |
3.34% |
2 |
1.82% |
| Rafael J. Wysocki |
86 |
3.31% |
4 |
3.64% |
| Nathan Fontenot |
85 |
3.27% |
1 |
0.91% |
| Rik Van Riel |
85 |
3.27% |
2 |
1.82% |
| Yasuaki Ishimatsu |
78 |
3.00% |
1 |
0.91% |
| Ben Hutchings |
74 |
2.84% |
2 |
1.82% |
| Toshi Kani |
72 |
2.77% |
4 |
3.64% |
| Vivek Goyal |
69 |
2.65% |
2 |
1.82% |
| Borislav Petkov |
64 |
2.46% |
4 |
3.64% |
| Joe Perches |
63 |
2.42% |
2 |
1.82% |
| Ashok Raj |
62 |
2.38% |
2 |
1.82% |
| Greg Kroah-Hartman |
56 |
2.15% |
6 |
5.45% |
| Andrew Morton |
49 |
1.88% |
5 |
4.55% |
| Waiman Long |
46 |
1.77% |
1 |
0.91% |
| Pawan Gupta |
30 |
1.15% |
2 |
1.82% |
| Zhang Yanfei |
27 |
1.04% |
1 |
0.91% |
| Josh Triplett |
24 |
0.92% |
1 |
0.91% |
| Len Brown |
24 |
0.92% |
1 |
0.91% |
| Frédéric Weisbecker |
23 |
0.88% |
3 |
2.73% |
| Patrick Mochel |
23 |
0.88% |
5 |
4.55% |
| Thomas Renninger |
19 |
0.73% |
1 |
0.91% |
| Eric DeVolder |
18 |
0.69% |
1 |
0.91% |
| Alex Shi |
16 |
0.61% |
2 |
1.82% |
| Kamezawa Hiroyuki |
15 |
0.58% |
1 |
0.91% |
| Mark Gross |
15 |
0.58% |
1 |
0.91% |
| Vineela Tummalapalli |
12 |
0.46% |
1 |
0.91% |
| Konrad Rzeszutek Wilk |
12 |
0.46% |
1 |
0.91% |
| Alexandre Chartre |
12 |
0.46% |
1 |
0.91% |
| Arvind Yadav |
10 |
0.38% |
1 |
0.91% |
| Daniel Sneddon |
7 |
0.27% |
1 |
0.91% |
| Mathieu Malaterre |
6 |
0.23% |
1 |
0.91% |
| Ben Dooks |
5 |
0.19% |
1 |
0.91% |
| Alan Stern |
5 |
0.19% |
1 |
0.91% |
| Joel A Fernandes |
5 |
0.19% |
1 |
0.91% |
| Linus Torvalds |
5 |
0.19% |
2 |
1.82% |
| Tejun Heo |
5 |
0.19% |
1 |
0.91% |
| Jan Beulich |
4 |
0.15% |
1 |
0.91% |
| Rasmus Villemoes |
3 |
0.12% |
1 |
0.91% |
| Avi Kivity |
3 |
0.12% |
1 |
0.91% |
| Qais Yousef |
3 |
0.12% |
1 |
0.91% |
| Linus Torvalds (pre-git) |
3 |
0.12% |
2 |
1.82% |
| Baoquan He |
3 |
0.12% |
1 |
0.91% |
| Jinchao Wang |
2 |
0.08% |
1 |
0.91% |
| Rikard Falkeborn |
2 |
0.08% |
1 |
0.91% |
| Takashi Iwai |
2 |
0.08% |
1 |
0.91% |
| Alexey Dobriyan |
2 |
0.08% |
1 |
0.91% |
| Robert P. J. Day |
1 |
0.04% |
1 |
0.91% |
| Colin Ian King |
1 |
0.04% |
1 |
0.91% |
| Ralf Baechle |
1 |
0.04% |
1 |
0.91% |
| Suresh B. Siddha |
1 |
0.04% |
1 |
0.91% |
| Arnd Bergmann |
1 |
0.04% |
1 |
0.91% |
| Total |
2602 |
|
110 |
|
// SPDX-License-Identifier: GPL-2.0
/*
* 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 <linux/delay.h>
#include <linux/sched/isolation.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;
int retries = 0;
from_nid = cpu_to_node(cpuid);
if (from_nid == NUMA_NO_NODE)
return -ENODEV;
retry:
ret = cpu_device_up(dev);
/*
* If -EBUSY is returned, it is likely that hotplug is temporarily
* disabled when cpu_hotplug_disable() was called. This condition is
* transient. So we retry after waiting for an exponentially
* increasing delay up to a total of at least 620ms as some PCI
* device initialization can take quite a while.
*/
if (ret == -EBUSY) {
retries++;
if (retries > 5)
return ret;
msleep(10 * (1 << retries));
goto retry;
}
/*
* 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_device_down(dev);
}
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 */
#ifdef CONFIG_KEXEC_CORE
#include <linux/kexec.h>
static ssize_t crash_notes_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct cpu *cpu = container_of(dev, struct cpu, dev);
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));
return sysfs_emit(buf, "%llx\n", addr);
}
static DEVICE_ATTR_ADMIN_RO(crash_notes);
static ssize_t crash_notes_size_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return sysfs_emit(buf, "%zu\n", sizeof(note_buf_t));
}
static DEVICE_ATTR_ADMIN_RO(crash_notes_size);
static struct attribute *crash_note_cpu_attrs[] = {
&dev_attr_crash_notes.attr,
&dev_attr_crash_notes_size.attr,
NULL
};
static const 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_CORE
&crash_note_cpu_attr_group,
#endif
NULL
};
static const struct attribute_group *hotplugable_cpu_attr_groups[] = {
#ifdef CONFIG_KEXEC_CORE
&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)
{
return sysfs_emit(buf, "%d\n", NR_CPUS - 1);
}
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 len = 0;
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);
len += sysfs_emit_at(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) {
len += sysfs_emit_at(buf, len, ",");
if (nr_cpu_ids == total_cpus-1)
len += sysfs_emit_at(buf, len, "%u", nr_cpu_ids);
else
len += sysfs_emit_at(buf, len, "%u-%d",
nr_cpu_ids, total_cpus - 1);
}
len += sysfs_emit_at(buf, len, "\n");
return len;
}
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 len;
cpumask_var_t isolated;
if (!alloc_cpumask_var(&isolated, GFP_KERNEL))
return -ENOMEM;
cpumask_andnot(isolated, cpu_possible_mask,
housekeeping_cpumask(HK_TYPE_DOMAIN));
len = sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(isolated));
free_cpumask_var(isolated);
return len;
}
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)
{
return sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(tick_nohz_full_mask));
}
static DEVICE_ATTR(nohz_full, 0444, print_cpus_nohz_full, NULL);
#endif
#ifdef CONFIG_CRASH_HOTPLUG
static ssize_t crash_hotplug_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return sysfs_emit(buf, "%d\n", crash_hotplug_cpu_support());
}
static DEVICE_ATTR_ADMIN_RO(crash_hotplug);
#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)
{
int len = 0;
u32 i;
len += sysfs_emit_at(buf, len,
"cpu:type:" CPU_FEATURE_TYPEFMT ":feature:",
CPU_FEATURE_TYPEVAL);
for (i = 0; i < MAX_CPU_FEATURES; i++)
if (cpu_have_feature(i)) {
if (len + sizeof(",XXXX\n") >= PAGE_SIZE) {
WARN(1, "CPU features overflow page\n");
break;
}
len += sysfs_emit_at(buf, len, ",%04X", i);
}
len += sysfs_emit_at(buf, len, "\n");
return len;
}
static int cpu_uevent(const 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
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
#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
.uevent = cpu_uevent,
#endif
};
EXPORT_SYMBOL_GPL(cpu_subsys);
/*
* 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);
cpu->dev.groups = common_cpu_attr_groups;
if (cpu->hotpluggable)
cpu->dev.groups = hotplugable_cpu_attr_groups;
error = device_register(&cpu->dev);
if (error) {
put_device(&cpu->dev);
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,
PM_QOS_RESUME_LATENCY_NO_CONSTRAINT);
return 0;
}
struct device *get_cpu_device(unsigned int 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);
}
__printf(4, 0)
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 = -ENOMEM;
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
goto error;
device_initialize(dev);
dev->parent = parent;
dev->groups = groups;
dev->release = device_create_release;
device_set_pm_not_required(dev);
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_CRASH_HOTPLUG
&dev_attr_crash_hotplug.attr,
#endif
#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
&dev_attr_modalias.attr,
#endif
NULL
};
static const 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 int cpu)
{
struct device *dev = get_cpu_device(cpu);
return dev && container_of(dev, struct cpu, dev)->hotpluggable
&& tick_nohz_cpu_hotpluggable(cpu);
}
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
}
#ifdef CONFIG_GENERIC_CPU_VULNERABILITIES
static ssize_t cpu_show_not_affected(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sysfs_emit(buf, "Not affected\n");
}
#define CPU_SHOW_VULN_FALLBACK(func) \
ssize_t cpu_show_##func(struct device *, \
struct device_attribute *, char *) \
__attribute__((weak, alias("cpu_show_not_affected")))
CPU_SHOW_VULN_FALLBACK(meltdown);
CPU_SHOW_VULN_FALLBACK(spectre_v1);
CPU_SHOW_VULN_FALLBACK(spectre_v2);
CPU_SHOW_VULN_FALLBACK(spec_store_bypass);
CPU_SHOW_VULN_FALLBACK(l1tf);
CPU_SHOW_VULN_FALLBACK(mds);
CPU_SHOW_VULN_FALLBACK(tsx_async_abort);
CPU_SHOW_VULN_FALLBACK(itlb_multihit);
CPU_SHOW_VULN_FALLBACK(srbds);
CPU_SHOW_VULN_FALLBACK(mmio_stale_data);
CPU_SHOW_VULN_FALLBACK(retbleed);
CPU_SHOW_VULN_FALLBACK(spec_rstack_overflow);
CPU_SHOW_VULN_FALLBACK(gds);
static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL);
static DEVICE_ATTR(spectre_v1, 0444, cpu_show_spectre_v1, NULL);
static DEVICE_ATTR(spectre_v2, 0444, cpu_show_spectre_v2, NULL);
static DEVICE_ATTR(spec_store_bypass, 0444, cpu_show_spec_store_bypass, NULL);
static DEVICE_ATTR(l1tf, 0444, cpu_show_l1tf, NULL);
static DEVICE_ATTR(mds, 0444, cpu_show_mds, NULL);
static DEVICE_ATTR(tsx_async_abort, 0444, cpu_show_tsx_async_abort, NULL);
static DEVICE_ATTR(itlb_multihit, 0444, cpu_show_itlb_multihit, NULL);
static DEVICE_ATTR(srbds, 0444, cpu_show_srbds, NULL);
static DEVICE_ATTR(mmio_stale_data, 0444, cpu_show_mmio_stale_data, NULL);
static DEVICE_ATTR(retbleed, 0444, cpu_show_retbleed, NULL);
static DEVICE_ATTR(spec_rstack_overflow, 0444, cpu_show_spec_rstack_overflow, NULL);
static DEVICE_ATTR(gather_data_sampling, 0444, cpu_show_gds, NULL);
static struct attribute *cpu_root_vulnerabilities_attrs[] = {
&dev_attr_meltdown.attr,
&dev_attr_spectre_v1.attr,
&dev_attr_spectre_v2.attr,
&dev_attr_spec_store_bypass.attr,
&dev_attr_l1tf.attr,
&dev_attr_mds.attr,
&dev_attr_tsx_async_abort.attr,
&dev_attr_itlb_multihit.attr,
&dev_attr_srbds.attr,
&dev_attr_mmio_stale_data.attr,
&dev_attr_retbleed.attr,
&dev_attr_spec_rstack_overflow.attr,
&dev_attr_gather_data_sampling.attr,
NULL
};
static const struct attribute_group cpu_root_vulnerabilities_group = {
.name = "vulnerabilities",
.attrs = cpu_root_vulnerabilities_attrs,
};
static void __init cpu_register_vulnerabilities(void)
{
struct device *dev = bus_get_dev_root(&cpu_subsys);
if (dev) {
if (sysfs_create_group(&dev->kobj, &cpu_root_vulnerabilities_group))
pr_err("Unable to register CPU vulnerabilities\n");
put_device(dev);
}
}
#else
static inline void cpu_register_vulnerabilities(void) { }
#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();
cpu_register_vulnerabilities();
}