linux/drivers/base/topology.c
Tian Tao bb9ec13d15 topology: use bin_attribute to break the size limitation of cpumap ABI
Reading /sys/devices/system/cpu/cpuX/topology/ returns cpu topology.
However, the size of this file is limited to PAGE_SIZE because of
the limitation for sysfs attribute.
This patch moves to use bin_attribute to extend the ABI to be more
than one page so that cpumap bitmask and list won't be potentially
trimmed.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Link: https://lore.kernel.org/r/20210806110251.560-4-song.bao.hua@hisilicon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-13 10:27:49 +02:00

155 lines
4.1 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* driver/base/topology.c - Populate sysfs with cpu topology information
*
* Written by: Zhang Yanmin, Intel Corporation
*
* Copyright (C) 2006, Intel Corp.
*
* All rights reserved.
*/
#include <linux/mm.h>
#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/hardirq.h>
#include <linux/topology.h>
#define define_id_show_func(name) \
static ssize_t name##_show(struct device *dev, \
struct device_attribute *attr, char *buf) \
{ \
return sysfs_emit(buf, "%d\n", topology_##name(dev->id)); \
}
#define define_siblings_read_func(name, mask) \
static ssize_t name##_read(struct file *file, struct kobject *kobj, \
struct bin_attribute *attr, char *buf, \
loff_t off, size_t count) \
{ \
struct device *dev = kobj_to_dev(kobj); \
\
return cpumap_print_bitmask_to_buf(buf, topology_##mask(dev->id), \
off, count); \
} \
\
static ssize_t name##_list_read(struct file *file, struct kobject *kobj, \
struct bin_attribute *attr, char *buf, \
loff_t off, size_t count) \
{ \
struct device *dev = kobj_to_dev(kobj); \
\
return cpumap_print_list_to_buf(buf, topology_##mask(dev->id), \
off, count); \
}
define_id_show_func(physical_package_id);
static DEVICE_ATTR_RO(physical_package_id);
define_id_show_func(die_id);
static DEVICE_ATTR_RO(die_id);
define_id_show_func(core_id);
static DEVICE_ATTR_RO(core_id);
define_siblings_read_func(thread_siblings, sibling_cpumask);
static BIN_ATTR_RO(thread_siblings, 0);
static BIN_ATTR_RO(thread_siblings_list, 0);
define_siblings_read_func(core_cpus, sibling_cpumask);
static BIN_ATTR_RO(core_cpus, 0);
static BIN_ATTR_RO(core_cpus_list, 0);
define_siblings_read_func(core_siblings, core_cpumask);
static BIN_ATTR_RO(core_siblings, 0);
static BIN_ATTR_RO(core_siblings_list, 0);
define_siblings_read_func(die_cpus, die_cpumask);
static BIN_ATTR_RO(die_cpus, 0);
static BIN_ATTR_RO(die_cpus_list, 0);
define_siblings_read_func(package_cpus, core_cpumask);
static BIN_ATTR_RO(package_cpus, 0);
static BIN_ATTR_RO(package_cpus_list, 0);
#ifdef CONFIG_SCHED_BOOK
define_id_show_func(book_id);
static DEVICE_ATTR_RO(book_id);
define_siblings_read_func(book_siblings, book_cpumask);
static BIN_ATTR_RO(book_siblings, 0);
static BIN_ATTR_RO(book_siblings_list, 0);
#endif
#ifdef CONFIG_SCHED_DRAWER
define_id_show_func(drawer_id);
static DEVICE_ATTR_RO(drawer_id);
define_siblings_read_func(drawer_siblings, drawer_cpumask);
static BIN_ATTR_RO(drawer_siblings, 0);
static BIN_ATTR_RO(drawer_siblings_list, 0);
#endif
static struct bin_attribute *bin_attrs[] = {
&bin_attr_core_cpus,
&bin_attr_core_cpus_list,
&bin_attr_thread_siblings,
&bin_attr_thread_siblings_list,
&bin_attr_core_siblings,
&bin_attr_core_siblings_list,
&bin_attr_die_cpus,
&bin_attr_die_cpus_list,
&bin_attr_package_cpus,
&bin_attr_package_cpus_list,
#ifdef CONFIG_SCHED_BOOK
&bin_attr_book_siblings,
&bin_attr_book_siblings_list,
#endif
#ifdef CONFIG_SCHED_DRAWER
&bin_attr_drawer_siblings,
&bin_attr_drawer_siblings_list,
#endif
NULL
};
static struct attribute *default_attrs[] = {
&dev_attr_physical_package_id.attr,
&dev_attr_die_id.attr,
&dev_attr_core_id.attr,
#ifdef CONFIG_SCHED_BOOK
&dev_attr_book_id.attr,
#endif
#ifdef CONFIG_SCHED_DRAWER
&dev_attr_drawer_id.attr,
#endif
NULL
};
static const struct attribute_group topology_attr_group = {
.attrs = default_attrs,
.bin_attrs = bin_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 int topology_remove_dev(unsigned int cpu)
{
struct device *dev = get_cpu_device(cpu);
sysfs_remove_group(&dev->kobj, &topology_attr_group);
return 0;
}
static int __init topology_sysfs_init(void)
{
return cpuhp_setup_state(CPUHP_TOPOLOGY_PREPARE,
"base/topology:prepare", topology_add_dev,
topology_remove_dev);
}
device_initcall(topology_sysfs_init);