kernel-ark/drivers/base/topology.c
Rafael J. Wysocki 8bb7844286 Add suspend-related notifications for CPU hotplug
Since nonboot CPUs are now disabled after tasks and devices have been
frozen and the CPU hotplug infrastructure is used for this purpose, we need
special CPU hotplug notifications that will help the CPU-hotplug-aware
subsystems distinguish normal CPU hotplug events from CPU hotplug events
related to a system-wide suspend or resume operation in progress.  This
patch introduces such notifications and causes them to be used during
suspend and resume transitions.  It also changes all of the
CPU-hotplug-aware subsystems to take these notifications into consideration
(for now they are handled in the same way as the corresponding "normal"
ones).

[oleg@tv-sign.ru: cleanups]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:56 -07:00

158 lines
4.0 KiB
C

/*
* driver/base/topology.c - Populate sysfs with cpu topology information
*
* Written by: Zhang Yanmin, Intel Corporation
*
* Copyright (C) 2006, Intel Corp.
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <linux/sysdev.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/topology.h>
#define define_one_ro(_name) \
static SYSDEV_ATTR(_name, 0444, show_##_name, NULL)
#define define_id_show_func(name) \
static ssize_t show_##name(struct sys_device *dev, char *buf) \
{ \
unsigned int cpu = dev->id; \
return sprintf(buf, "%d\n", topology_##name(cpu)); \
}
#define define_siblings_show_func(name) \
static ssize_t show_##name(struct sys_device *dev, char *buf) \
{ \
ssize_t len = -1; \
unsigned int cpu = dev->id; \
len = cpumask_scnprintf(buf, NR_CPUS+1, topology_##name(cpu)); \
return (len + sprintf(buf + len, "\n")); \
}
#ifdef topology_physical_package_id
define_id_show_func(physical_package_id);
define_one_ro(physical_package_id);
#define ref_physical_package_id_attr &attr_physical_package_id.attr,
#else
#define ref_physical_package_id_attr
#endif
#ifdef topology_core_id
define_id_show_func(core_id);
define_one_ro(core_id);
#define ref_core_id_attr &attr_core_id.attr,
#else
#define ref_core_id_attr
#endif
#ifdef topology_thread_siblings
define_siblings_show_func(thread_siblings);
define_one_ro(thread_siblings);
#define ref_thread_siblings_attr &attr_thread_siblings.attr,
#else
#define ref_thread_siblings_attr
#endif
#ifdef topology_core_siblings
define_siblings_show_func(core_siblings);
define_one_ro(core_siblings);
#define ref_core_siblings_attr &attr_core_siblings.attr,
#else
#define ref_core_siblings_attr
#endif
static struct attribute *default_attrs[] = {
ref_physical_package_id_attr
ref_core_id_attr
ref_thread_siblings_attr
ref_core_siblings_attr
NULL
};
static struct attribute_group topology_attr_group = {
.attrs = default_attrs,
.name = "topology"
};
static cpumask_t topology_dev_map = CPU_MASK_NONE;
/* Add/Remove cpu_topology interface for CPU device */
static int __cpuinit topology_add_dev(unsigned int cpu)
{
int rc;
struct sys_device *sys_dev = get_cpu_sysdev(cpu);
rc = sysfs_create_group(&sys_dev->kobj, &topology_attr_group);
if (!rc)
cpu_set(cpu, topology_dev_map);
return rc;
}
static void __cpuinit topology_remove_dev(unsigned int cpu)
{
struct sys_device *sys_dev = get_cpu_sysdev(cpu);
if (!cpu_isset(cpu, topology_dev_map))
return;
cpu_clear(cpu, topology_dev_map);
sysfs_remove_group(&sys_dev->kobj, &topology_attr_group);
}
static int __cpuinit topology_cpu_callback(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
int rc = 0;
switch (action) {
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
rc = topology_add_dev(cpu);
break;
case CPU_UP_CANCELED:
case CPU_UP_CANCELED_FROZEN:
case CPU_DEAD:
case CPU_DEAD_FROZEN:
topology_remove_dev(cpu);
break;
}
return rc ? NOTIFY_BAD : NOTIFY_OK;
}
static int __cpuinit topology_sysfs_init(void)
{
int cpu;
int rc;
for_each_online_cpu(cpu) {
rc = topology_add_dev(cpu);
if (rc)
return rc;
}
hotcpu_notifier(topology_cpu_callback, 0);
return 0;
}
device_initcall(topology_sysfs_init);