linux/drivers/base/topology.c
Hanjun Guo 29f1953d51 cpu topology: remove stale arch_provides_topology_pointers and define_siblings_show_map/list()
arch_provides_topology_pointers was introduced in commit 23ca4bba3 (x86:
cleanup early per cpu variables/accesses v4) to indicate pointers to the
topology cpumask_t maps are valid to avoid copying data on to/off of the
stack.

But later in commit fbd59a8d (cpumask: Use topology_core_cpumask()/
topology_thread_cpumask()), the pointers to the topology struct cpumask maps
are always valid.

After that commit, the only difference is that there is a redundant
"unsigned int cpu = dev->id;" if arch_provides_topology_pointers defined, but
dev->id is type 'u32' which devolves to 'unsigned int' on all supported arches.
So this arch_provides_topology_pointers define is pointless and only cause
obfuscation now, remove it.

Tested on x86 machine, topology information in sys/devices/system/cpu/
cpuX/topology/ is the same after appling this patch set.

Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-29 13:12:45 -07:00

177 lines
4.6 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/init.h>
#include <linux/mm.h>
#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/hardirq.h>
#include <linux/topology.h>
#define define_one_ro_named(_name, _func) \
static DEVICE_ATTR(_name, 0444, _func, NULL)
#define define_one_ro(_name) \
static DEVICE_ATTR(_name, 0444, show_##_name, NULL)
#define define_id_show_func(name) \
static ssize_t show_##name(struct device *dev, \
struct device_attribute *attr, char *buf) \
{ \
unsigned int cpu = dev->id; \
return sprintf(buf, "%d\n", topology_##name(cpu)); \
}
#if defined(topology_thread_cpumask) || defined(topology_core_cpumask) || \
defined(topology_book_cpumask)
static ssize_t show_cpumap(int type, const struct cpumask *mask, char *buf)
{
ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf;
int n = 0;
if (len > 1) {
n = type?
cpulist_scnprintf(buf, len-2, mask) :
cpumask_scnprintf(buf, len-2, mask);
buf[n++] = '\n';
buf[n] = '\0';
}
return n;
}
#endif
#define define_siblings_show_map(name) \
static ssize_t show_##name(struct device *dev, \
struct device_attribute *attr, char *buf) \
{ \
return show_cpumap(0, topology_##name(dev->id), buf); \
}
#define define_siblings_show_list(name) \
static ssize_t show_##name##_list(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
return show_cpumap(1, topology_##name(dev->id), buf); \
}
#define define_siblings_show_func(name) \
define_siblings_show_map(name); define_siblings_show_list(name)
define_id_show_func(physical_package_id);
define_one_ro(physical_package_id);
define_id_show_func(core_id);
define_one_ro(core_id);
define_siblings_show_func(thread_cpumask);
define_one_ro_named(thread_siblings, show_thread_cpumask);
define_one_ro_named(thread_siblings_list, show_thread_cpumask_list);
define_siblings_show_func(core_cpumask);
define_one_ro_named(core_siblings, show_core_cpumask);
define_one_ro_named(core_siblings_list, show_core_cpumask_list);
#ifdef CONFIG_SCHED_BOOK
define_id_show_func(book_id);
define_one_ro(book_id);
define_siblings_show_func(book_cpumask);
define_one_ro_named(book_siblings, show_book_cpumask);
define_one_ro_named(book_siblings_list, show_book_cpumask_list);
#endif
static struct attribute *default_attrs[] = {
&dev_attr_physical_package_id.attr,
&dev_attr_core_id.attr,
&dev_attr_thread_siblings.attr,
&dev_attr_thread_siblings_list.attr,
&dev_attr_core_siblings.attr,
&dev_attr_core_siblings_list.attr,
#ifdef CONFIG_SCHED_BOOK
&dev_attr_book_id.attr,
&dev_attr_book_siblings.attr,
&dev_attr_book_siblings_list.attr,
#endif
NULL
};
static struct attribute_group topology_attr_group = {
.attrs = default_attrs,
.name = "topology"
};
/* Add/Remove cpu_topology interface for CPU device */
static int topology_add_dev(unsigned int cpu)
{
struct device *dev = get_cpu_device(cpu);
return sysfs_create_group(&dev->kobj, &topology_attr_group);
}
static void topology_remove_dev(unsigned int cpu)
{
struct device *dev = get_cpu_device(cpu);
sysfs_remove_group(&dev->kobj, &topology_attr_group);
}
static int 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 notifier_from_errno(rc);
}
static int 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);