Revision 40509ca982c00c4b70fc00be887509feca0bff15 authored by Johan Hovold on 19 March 2013, 08:21:22 UTC, committed by Greg Kroah-Hartman on 21 March 2013, 22:59:05 UTC
Use the port wait queue and make sure to check the serial disconnected flag before accessing private port data after waking up. This is is needed as the private port data (including the wait queue itself) can be gone when waking up after a disconnect. Cc: stable <stable@vger.kernel.org> Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 parent 8edfdab
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 "base.h"
struct bus_type cpu_subsys = {
.name = "cpu",
.dev_name = "cpu",
};
EXPORT_SYMBOL_GPL(cpu_subsys);
static DEFINE_PER_CPU(struct device *, cpu_sys_devices);
#ifdef CONFIG_HOTPLUG_CPU
static ssize_t show_online(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct cpu *cpu = container_of(dev, struct cpu, dev);
return sprintf(buf, "%u\n", !!cpu_online(cpu->dev.id));
}
static ssize_t __ref store_online(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct cpu *cpu = container_of(dev, struct cpu, dev);
ssize_t ret;
cpu_hotplug_driver_lock();
switch (buf[0]) {
case '0':
ret = cpu_down(cpu->dev.id);
if (!ret)
kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
break;
case '1':
ret = cpu_up(cpu->dev.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 DEVICE_ATTR(online, 0644, show_online, store_online);
static void __cpuinit register_cpu_control(struct cpu *cpu)
{
device_create_file(&cpu->dev, &dev_attr_online);
}
void unregister_cpu(struct cpu *cpu)
{
int logical_cpu = cpu->dev.id;
unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));
device_remove_file(&cpu->dev, &dev_attr_online);
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)
{
return arch_cpu_probe(buf, count);
}
static ssize_t cpu_release_store(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t count)
{
return arch_cpu_release(buf, count);
}
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 */
#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 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);
#endif
/*
* Print cpu online, possible, present, and system maps
*/
struct cpu_attr {
struct device_attribute attr;
const struct cpumask *const * 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);
int n = cpulist_scnprintf(buf, PAGE_SIZE-2, *(ca->map));
buf[n++] = '\n';
buf[n] = '\0';
return n;
}
#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 = 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 DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL);
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.
*/
}
/*
* 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);
memset(&cpu->dev, 0x00, sizeof(struct device));
cpu->dev.id = num;
cpu->dev.bus = &cpu_subsys;
cpu->dev.release = cpu_device_release;
#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
cpu->dev.bus->uevent = arch_cpu_uevent;
#endif
error = device_register(&cpu->dev);
if (!error && cpu->hotpluggable)
register_cpu_control(cpu);
if (!error)
per_cpu(cpu_sys_devices, num) = &cpu->dev;
if (!error)
register_cpu_under_node(num, cpu_to_node(num));
#ifdef CONFIG_KEXEC
if (!error)
error = device_create_file(&cpu->dev, &dev_attr_crash_notes);
#endif
return error;
}
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);
#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
static DEVICE_ATTR(modalias, 0444, arch_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,
#ifdef CONFIG_ARCH_HAS_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();
}
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