linux/drivers/base/topology.c
Tony Luck ab28e94419 topology/sysfs: Add PPIN in sysfs under cpu topology
PPIN is the Protected Processor Identification Number.
This is used to identify the socket as a Field Replaceable Unit (FRU).

Existing code only displays this when reporting errors. But this makes
it inconvenient for large clusters to use it for its intended purpose
of inventory control.

Add ppin to /sys/devices/system/cpu/cpu*/topology to make what
is already available using RDMSR more easily accessible. Make
the file read only for root in case there are still people
concerned about making a unique system "serial number" available.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20220131230111.2004669-6-tony.luck@intel.com
2022-02-01 16:36:42 +01:00

185 lines
4.8 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, fmt) \
static ssize_t name##_show(struct device *dev, \
struct device_attribute *attr, char *buf) \
{ \
return sysfs_emit(buf, fmt "\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, "%d");
static DEVICE_ATTR_RO(physical_package_id);
#ifdef TOPOLOGY_DIE_SYSFS
define_id_show_func(die_id, "%d");
static DEVICE_ATTR_RO(die_id);
#endif
#ifdef TOPOLOGY_CLUSTER_SYSFS
define_id_show_func(cluster_id, "%d");
static DEVICE_ATTR_RO(cluster_id);
#endif
define_id_show_func(core_id, "%d");
static DEVICE_ATTR_RO(core_id);
define_id_show_func(ppin, "0x%llx");
static DEVICE_ATTR_ADMIN_RO(ppin);
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);
#ifdef TOPOLOGY_CLUSTER_SYSFS
define_siblings_read_func(cluster_cpus, cluster_cpumask);
static BIN_ATTR_RO(cluster_cpus, 0);
static BIN_ATTR_RO(cluster_cpus_list, 0);
#endif
#ifdef TOPOLOGY_DIE_SYSFS
define_siblings_read_func(die_cpus, die_cpumask);
static BIN_ATTR_RO(die_cpus, 0);
static BIN_ATTR_RO(die_cpus_list, 0);
#endif
define_siblings_read_func(package_cpus, core_cpumask);
static BIN_ATTR_RO(package_cpus, 0);
static BIN_ATTR_RO(package_cpus_list, 0);
#ifdef TOPOLOGY_BOOK_SYSFS
define_id_show_func(book_id, "%d");
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 TOPOLOGY_DRAWER_SYSFS
define_id_show_func(drawer_id, "%d");
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,
#ifdef TOPOLOGY_CLUSTER_SYSFS
&bin_attr_cluster_cpus,
&bin_attr_cluster_cpus_list,
#endif
#ifdef TOPOLOGY_DIE_SYSFS
&bin_attr_die_cpus,
&bin_attr_die_cpus_list,
#endif
&bin_attr_package_cpus,
&bin_attr_package_cpus_list,
#ifdef TOPOLOGY_BOOK_SYSFS
&bin_attr_book_siblings,
&bin_attr_book_siblings_list,
#endif
#ifdef TOPOLOGY_DRAWER_SYSFS
&bin_attr_drawer_siblings,
&bin_attr_drawer_siblings_list,
#endif
NULL
};
static struct attribute *default_attrs[] = {
&dev_attr_physical_package_id.attr,
#ifdef TOPOLOGY_DIE_SYSFS
&dev_attr_die_id.attr,
#endif
#ifdef TOPOLOGY_CLUSTER_SYSFS
&dev_attr_cluster_id.attr,
#endif
&dev_attr_core_id.attr,
#ifdef TOPOLOGY_BOOK_SYSFS
&dev_attr_book_id.attr,
#endif
#ifdef TOPOLOGY_DRAWER_SYSFS
&dev_attr_drawer_id.attr,
#endif
&dev_attr_ppin.attr,
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);