mirror of https://gitee.com/openkylin/linux.git
610 lines
15 KiB
C
610 lines
15 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* CPU subsystem support
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/sched.h>
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#include <linux/cpu.h>
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#include <linux/topology.h>
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#include <linux/device.h>
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#include <linux/node.h>
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#include <linux/gfp.h>
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#include <linux/slab.h>
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#include <linux/percpu.h>
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#include <linux/acpi.h>
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#include <linux/of.h>
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#include <linux/cpufeature.h>
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#include <linux/tick.h>
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#include <linux/pm_qos.h>
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#include <linux/sched/isolation.h>
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#include "base.h"
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static DEFINE_PER_CPU(struct device *, cpu_sys_devices);
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static int cpu_subsys_match(struct device *dev, struct device_driver *drv)
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{
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/* ACPI style match is the only one that may succeed. */
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if (acpi_driver_match_device(dev, drv))
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return 1;
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return 0;
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}
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#ifdef CONFIG_HOTPLUG_CPU
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static void change_cpu_under_node(struct cpu *cpu,
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unsigned int from_nid, unsigned int to_nid)
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{
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int cpuid = cpu->dev.id;
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unregister_cpu_under_node(cpuid, from_nid);
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register_cpu_under_node(cpuid, to_nid);
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cpu->node_id = to_nid;
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}
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static int cpu_subsys_online(struct device *dev)
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{
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struct cpu *cpu = container_of(dev, struct cpu, dev);
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int cpuid = dev->id;
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int from_nid, to_nid;
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int ret;
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from_nid = cpu_to_node(cpuid);
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if (from_nid == NUMA_NO_NODE)
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return -ENODEV;
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ret = cpu_device_up(dev);
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/*
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* When hot adding memory to memoryless node and enabling a cpu
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* on the node, node number of the cpu may internally change.
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*/
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to_nid = cpu_to_node(cpuid);
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if (from_nid != to_nid)
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change_cpu_under_node(cpu, from_nid, to_nid);
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return ret;
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}
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static int cpu_subsys_offline(struct device *dev)
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{
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return cpu_device_down(dev);
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}
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void unregister_cpu(struct cpu *cpu)
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{
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int logical_cpu = cpu->dev.id;
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unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));
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device_unregister(&cpu->dev);
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per_cpu(cpu_sys_devices, logical_cpu) = NULL;
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return;
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}
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#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
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static ssize_t cpu_probe_store(struct device *dev,
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struct device_attribute *attr,
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const char *buf,
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size_t count)
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{
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ssize_t cnt;
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int ret;
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ret = lock_device_hotplug_sysfs();
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if (ret)
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return ret;
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cnt = arch_cpu_probe(buf, count);
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unlock_device_hotplug();
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return cnt;
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}
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static ssize_t cpu_release_store(struct device *dev,
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struct device_attribute *attr,
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const char *buf,
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size_t count)
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{
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ssize_t cnt;
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int ret;
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ret = lock_device_hotplug_sysfs();
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if (ret)
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return ret;
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cnt = arch_cpu_release(buf, count);
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unlock_device_hotplug();
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return cnt;
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}
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static DEVICE_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
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static DEVICE_ATTR(release, S_IWUSR, NULL, cpu_release_store);
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#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
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#endif /* CONFIG_HOTPLUG_CPU */
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struct bus_type cpu_subsys = {
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.name = "cpu",
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.dev_name = "cpu",
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.match = cpu_subsys_match,
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#ifdef CONFIG_HOTPLUG_CPU
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.online = cpu_subsys_online,
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.offline = cpu_subsys_offline,
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#endif
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};
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EXPORT_SYMBOL_GPL(cpu_subsys);
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#ifdef CONFIG_KEXEC
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#include <linux/kexec.h>
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static ssize_t show_crash_notes(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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struct cpu *cpu = container_of(dev, struct cpu, dev);
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ssize_t rc;
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unsigned long long addr;
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int cpunum;
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cpunum = cpu->dev.id;
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/*
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* Might be reading other cpu's data based on which cpu read thread
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* has been scheduled. But cpu data (memory) is allocated once during
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* boot up and this data does not change there after. Hence this
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* operation should be safe. No locking required.
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*/
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addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpunum));
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rc = sprintf(buf, "%Lx\n", addr);
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return rc;
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}
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static DEVICE_ATTR(crash_notes, 0400, show_crash_notes, NULL);
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static ssize_t show_crash_notes_size(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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ssize_t rc;
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rc = sprintf(buf, "%zu\n", sizeof(note_buf_t));
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return rc;
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}
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static DEVICE_ATTR(crash_notes_size, 0400, show_crash_notes_size, NULL);
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static struct attribute *crash_note_cpu_attrs[] = {
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&dev_attr_crash_notes.attr,
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&dev_attr_crash_notes_size.attr,
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NULL
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};
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static struct attribute_group crash_note_cpu_attr_group = {
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.attrs = crash_note_cpu_attrs,
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};
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#endif
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static const struct attribute_group *common_cpu_attr_groups[] = {
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#ifdef CONFIG_KEXEC
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&crash_note_cpu_attr_group,
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#endif
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NULL
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};
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static const struct attribute_group *hotplugable_cpu_attr_groups[] = {
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#ifdef CONFIG_KEXEC
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&crash_note_cpu_attr_group,
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#endif
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NULL
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};
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/*
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* Print cpu online, possible, present, and system maps
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*/
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struct cpu_attr {
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struct device_attribute attr;
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const struct cpumask *const map;
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};
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static ssize_t show_cpus_attr(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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struct cpu_attr *ca = container_of(attr, struct cpu_attr, attr);
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return cpumap_print_to_pagebuf(true, buf, ca->map);
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}
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#define _CPU_ATTR(name, map) \
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{ __ATTR(name, 0444, show_cpus_attr, NULL), map }
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/* Keep in sync with cpu_subsys_attrs */
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static struct cpu_attr cpu_attrs[] = {
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_CPU_ATTR(online, &__cpu_online_mask),
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_CPU_ATTR(possible, &__cpu_possible_mask),
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_CPU_ATTR(present, &__cpu_present_mask),
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};
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/*
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* Print values for NR_CPUS and offlined cpus
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*/
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static ssize_t print_cpus_kernel_max(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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return sprintf(buf, "%d\n", NR_CPUS - 1);
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}
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static DEVICE_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL);
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/* arch-optional setting to enable display of offline cpus >= nr_cpu_ids */
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unsigned int total_cpus;
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static ssize_t print_cpus_offline(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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int n = 0, len = PAGE_SIZE-2;
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cpumask_var_t offline;
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/* display offline cpus < nr_cpu_ids */
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if (!alloc_cpumask_var(&offline, GFP_KERNEL))
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return -ENOMEM;
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cpumask_andnot(offline, cpu_possible_mask, cpu_online_mask);
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n = scnprintf(buf, len, "%*pbl", cpumask_pr_args(offline));
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free_cpumask_var(offline);
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/* display offline cpus >= nr_cpu_ids */
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if (total_cpus && nr_cpu_ids < total_cpus) {
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if (n && n < len)
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buf[n++] = ',';
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if (nr_cpu_ids == total_cpus-1)
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n += scnprintf(&buf[n], len - n, "%u", nr_cpu_ids);
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else
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n += scnprintf(&buf[n], len - n, "%u-%d",
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nr_cpu_ids, total_cpus-1);
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}
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n += scnprintf(&buf[n], len - n, "\n");
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return n;
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}
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static DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL);
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static ssize_t print_cpus_isolated(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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int n;
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cpumask_var_t isolated;
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if (!alloc_cpumask_var(&isolated, GFP_KERNEL))
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return -ENOMEM;
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cpumask_andnot(isolated, cpu_possible_mask,
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housekeeping_cpumask(HK_FLAG_DOMAIN));
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n = sprintf(buf, "%*pbl\n", cpumask_pr_args(isolated));
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free_cpumask_var(isolated);
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return n;
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}
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static DEVICE_ATTR(isolated, 0444, print_cpus_isolated, NULL);
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#ifdef CONFIG_NO_HZ_FULL
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static ssize_t print_cpus_nohz_full(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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return sprintf(buf, "%*pbl\n", cpumask_pr_args(tick_nohz_full_mask));
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}
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static DEVICE_ATTR(nohz_full, 0444, print_cpus_nohz_full, NULL);
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#endif
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static void cpu_device_release(struct device *dev)
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{
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/*
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* This is an empty function to prevent the driver core from spitting a
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* warning at us. Yes, I know this is directly opposite of what the
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* documentation for the driver core and kobjects say, and the author
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* of this code has already been publically ridiculed for doing
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* something as foolish as this. However, at this point in time, it is
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* the only way to handle the issue of statically allocated cpu
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* devices. The different architectures will have their cpu device
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* code reworked to properly handle this in the near future, so this
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* function will then be changed to correctly free up the memory held
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* by the cpu device.
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*
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* Never copy this way of doing things, or you too will be made fun of
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* on the linux-kernel list, you have been warned.
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*/
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}
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#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
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static ssize_t print_cpu_modalias(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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ssize_t n;
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u32 i;
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n = sprintf(buf, "cpu:type:" CPU_FEATURE_TYPEFMT ":feature:",
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CPU_FEATURE_TYPEVAL);
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for (i = 0; i < MAX_CPU_FEATURES; i++)
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if (cpu_have_feature(i)) {
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if (PAGE_SIZE < n + sizeof(",XXXX\n")) {
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WARN(1, "CPU features overflow page\n");
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break;
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}
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n += sprintf(&buf[n], ",%04X", i);
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}
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buf[n++] = '\n';
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return n;
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}
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static int cpu_uevent(struct device *dev, struct kobj_uevent_env *env)
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{
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char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
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if (buf) {
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print_cpu_modalias(NULL, NULL, buf);
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add_uevent_var(env, "MODALIAS=%s", buf);
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kfree(buf);
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}
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return 0;
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}
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#endif
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/*
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* register_cpu - Setup a sysfs device for a CPU.
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* @cpu - cpu->hotpluggable field set to 1 will generate a control file in
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* sysfs for this CPU.
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* @num - CPU number to use when creating the device.
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*
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* Initialize and register the CPU device.
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*/
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int register_cpu(struct cpu *cpu, int num)
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{
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int error;
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cpu->node_id = cpu_to_node(num);
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memset(&cpu->dev, 0x00, sizeof(struct device));
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cpu->dev.id = num;
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cpu->dev.bus = &cpu_subsys;
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cpu->dev.release = cpu_device_release;
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cpu->dev.offline_disabled = !cpu->hotpluggable;
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cpu->dev.offline = !cpu_online(num);
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cpu->dev.of_node = of_get_cpu_node(num, NULL);
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#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
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cpu->dev.bus->uevent = cpu_uevent;
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#endif
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cpu->dev.groups = common_cpu_attr_groups;
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if (cpu->hotpluggable)
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cpu->dev.groups = hotplugable_cpu_attr_groups;
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error = device_register(&cpu->dev);
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if (error) {
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put_device(&cpu->dev);
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return error;
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}
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per_cpu(cpu_sys_devices, num) = &cpu->dev;
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register_cpu_under_node(num, cpu_to_node(num));
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dev_pm_qos_expose_latency_limit(&cpu->dev,
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PM_QOS_RESUME_LATENCY_NO_CONSTRAINT);
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return 0;
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}
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struct device *get_cpu_device(unsigned cpu)
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{
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if (cpu < nr_cpu_ids && cpu_possible(cpu))
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return per_cpu(cpu_sys_devices, cpu);
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else
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return NULL;
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}
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EXPORT_SYMBOL_GPL(get_cpu_device);
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static void device_create_release(struct device *dev)
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{
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kfree(dev);
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}
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__printf(4, 0)
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static struct device *
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__cpu_device_create(struct device *parent, void *drvdata,
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const struct attribute_group **groups,
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const char *fmt, va_list args)
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{
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struct device *dev = NULL;
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int retval = -ENODEV;
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dev = kzalloc(sizeof(*dev), GFP_KERNEL);
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if (!dev) {
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retval = -ENOMEM;
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goto error;
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}
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device_initialize(dev);
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dev->parent = parent;
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dev->groups = groups;
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dev->release = device_create_release;
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device_set_pm_not_required(dev);
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dev_set_drvdata(dev, drvdata);
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retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
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if (retval)
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goto error;
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retval = device_add(dev);
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if (retval)
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goto error;
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return dev;
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error:
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put_device(dev);
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return ERR_PTR(retval);
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}
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struct device *cpu_device_create(struct device *parent, void *drvdata,
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const struct attribute_group **groups,
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const char *fmt, ...)
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{
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va_list vargs;
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struct device *dev;
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va_start(vargs, fmt);
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dev = __cpu_device_create(parent, drvdata, groups, fmt, vargs);
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va_end(vargs);
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return dev;
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}
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EXPORT_SYMBOL_GPL(cpu_device_create);
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#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
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static DEVICE_ATTR(modalias, 0444, print_cpu_modalias, NULL);
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#endif
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static struct attribute *cpu_root_attrs[] = {
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#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
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&dev_attr_probe.attr,
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&dev_attr_release.attr,
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#endif
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&cpu_attrs[0].attr.attr,
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&cpu_attrs[1].attr.attr,
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&cpu_attrs[2].attr.attr,
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&dev_attr_kernel_max.attr,
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&dev_attr_offline.attr,
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&dev_attr_isolated.attr,
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#ifdef CONFIG_NO_HZ_FULL
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&dev_attr_nohz_full.attr,
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#endif
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#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
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&dev_attr_modalias.attr,
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#endif
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NULL
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};
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static struct attribute_group cpu_root_attr_group = {
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.attrs = cpu_root_attrs,
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};
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static const struct attribute_group *cpu_root_attr_groups[] = {
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&cpu_root_attr_group,
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NULL,
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};
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bool cpu_is_hotpluggable(unsigned cpu)
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{
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struct device *dev = get_cpu_device(cpu);
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return dev && container_of(dev, struct cpu, dev)->hotpluggable;
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}
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EXPORT_SYMBOL_GPL(cpu_is_hotpluggable);
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#ifdef CONFIG_GENERIC_CPU_DEVICES
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static DEFINE_PER_CPU(struct cpu, cpu_devices);
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#endif
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static void __init cpu_dev_register_generic(void)
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{
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#ifdef CONFIG_GENERIC_CPU_DEVICES
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int i;
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for_each_possible_cpu(i) {
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if (register_cpu(&per_cpu(cpu_devices, i), i))
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panic("Failed to register CPU device");
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}
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#endif
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}
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#ifdef CONFIG_GENERIC_CPU_VULNERABILITIES
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ssize_t __weak cpu_show_meltdown(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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return sprintf(buf, "Not affected\n");
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}
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ssize_t __weak cpu_show_spectre_v1(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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return sprintf(buf, "Not affected\n");
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}
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ssize_t __weak cpu_show_spectre_v2(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
|
|
return sprintf(buf, "Not affected\n");
|
|
}
|
|
|
|
ssize_t __weak cpu_show_spec_store_bypass(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
return sprintf(buf, "Not affected\n");
|
|
}
|
|
|
|
ssize_t __weak cpu_show_l1tf(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
return sprintf(buf, "Not affected\n");
|
|
}
|
|
|
|
ssize_t __weak cpu_show_mds(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
return sprintf(buf, "Not affected\n");
|
|
}
|
|
|
|
ssize_t __weak cpu_show_tsx_async_abort(struct device *dev,
|
|
struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
return sprintf(buf, "Not affected\n");
|
|
}
|
|
|
|
ssize_t __weak cpu_show_itlb_multihit(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
return sprintf(buf, "Not affected\n");
|
|
}
|
|
|
|
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 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,
|
|
NULL
|
|
};
|
|
|
|
static const struct attribute_group cpu_root_vulnerabilities_group = {
|
|
.name = "vulnerabilities",
|
|
.attrs = cpu_root_vulnerabilities_attrs,
|
|
};
|
|
|
|
static void __init cpu_register_vulnerabilities(void)
|
|
{
|
|
if (sysfs_create_group(&cpu_subsys.dev_root->kobj,
|
|
&cpu_root_vulnerabilities_group))
|
|
pr_err("Unable to register CPU vulnerabilities\n");
|
|
}
|
|
|
|
#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();
|
|
}
|