topology.c

  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * driver/base/topology.c - Populate sysfs with cpu topology information
  4 *
  5 * Written by: Zhang Yanmin, Intel Corporation
  6 *
  7 * Copyright (C) 2006, Intel Corp.
  8 *
  9 * All rights reserved.
 10 */
 11#include <linux/mm.h>
 12#include <linux/cpu.h>
 13#include <linux/module.h>
 14#include <linux/hardirq.h>
 15#include <linux/topology.h>
 16
 17#define define_id_show_func(name, fmt)					\
 18static ssize_t name##_show(struct device *dev,				\
 19			   struct device_attribute *attr, char *buf)	\
 20{									\
 21	return sysfs_emit(buf, fmt "\n", topology_##name(dev->id));	\
 22}
 23
 24#define define_siblings_read_func(name, mask)					\
 25static ssize_t name##_read(struct file *file, struct kobject *kobj,		\
 26			   const struct bin_attribute *attr, char *buf,		\
 27			   loff_t off, size_t count)				\
 28{										\
 29	struct device *dev = kobj_to_dev(kobj);                                 \
 30	cpumask_var_t mask;							\
 31	ssize_t n;								\
 32										\
 33	if (!alloc_cpumask_var(&mask, GFP_KERNEL))				\
 34		return -ENOMEM;							\
 35										\
 36	cpumask_copy(mask, topology_##mask(dev->id));				\
 37	n = cpumap_print_bitmask_to_buf(buf, mask, off, count);			\
 38	free_cpumask_var(mask);							\
 39										\
 40	return n;								\
 41}										\
 42										\
 43static ssize_t name##_list_read(struct file *file, struct kobject *kobj,	\
 44				const struct bin_attribute *attr, char *buf,	\
 45				loff_t off, size_t count)			\
 46{										\
 47	struct device *dev = kobj_to_dev(kobj);					\
 48	cpumask_var_t mask;							\
 49	ssize_t n;								\
 50										\
 51	if (!alloc_cpumask_var(&mask, GFP_KERNEL))				\
 52		return -ENOMEM;							\
 53										\
 54	cpumask_copy(mask, topology_##mask(dev->id));				\
 55	n = cpumap_print_list_to_buf(buf, mask, off, count);			\
 56	free_cpumask_var(mask);							\
 57										\
 58	return n;								\
 59}
 60
 61define_id_show_func(physical_package_id, "%d");
 62static DEVICE_ATTR_RO(physical_package_id);
 63
 64#ifdef TOPOLOGY_DIE_SYSFS
 65define_id_show_func(die_id, "%d");
 66static DEVICE_ATTR_RO(die_id);
 67#endif
 68
 69#ifdef TOPOLOGY_CLUSTER_SYSFS
 70define_id_show_func(cluster_id, "%d");
 71static DEVICE_ATTR_RO(cluster_id);
 72#endif
 73
 74define_id_show_func(core_id, "%d");
 75static DEVICE_ATTR_RO(core_id);
 76
 77define_id_show_func(ppin, "0x%llx");
 78static DEVICE_ATTR_ADMIN_RO(ppin);
 79
 80define_siblings_read_func(thread_siblings, sibling_cpumask);
 81static const BIN_ATTR_RO(thread_siblings, CPUMAP_FILE_MAX_BYTES);
 82static const BIN_ATTR_RO(thread_siblings_list, CPULIST_FILE_MAX_BYTES);
 83
 84define_siblings_read_func(core_cpus, sibling_cpumask);
 85static const BIN_ATTR_RO(core_cpus, CPUMAP_FILE_MAX_BYTES);
 86static const BIN_ATTR_RO(core_cpus_list, CPULIST_FILE_MAX_BYTES);
 87
 88define_siblings_read_func(core_siblings, core_cpumask);
 89static const BIN_ATTR_RO(core_siblings, CPUMAP_FILE_MAX_BYTES);
 90static const BIN_ATTR_RO(core_siblings_list, CPULIST_FILE_MAX_BYTES);
 91
 92#ifdef TOPOLOGY_CLUSTER_SYSFS
 93define_siblings_read_func(cluster_cpus, cluster_cpumask);
 94static const BIN_ATTR_RO(cluster_cpus, CPUMAP_FILE_MAX_BYTES);
 95static const BIN_ATTR_RO(cluster_cpus_list, CPULIST_FILE_MAX_BYTES);
 96#endif
 97
 98#ifdef TOPOLOGY_DIE_SYSFS
 99define_siblings_read_func(die_cpus, die_cpumask);
100static const BIN_ATTR_RO(die_cpus, CPUMAP_FILE_MAX_BYTES);
101static const BIN_ATTR_RO(die_cpus_list, CPULIST_FILE_MAX_BYTES);
102#endif
103
104define_siblings_read_func(package_cpus, core_cpumask);
105static const BIN_ATTR_RO(package_cpus, CPUMAP_FILE_MAX_BYTES);
106static const BIN_ATTR_RO(package_cpus_list, CPULIST_FILE_MAX_BYTES);
107
108#ifdef TOPOLOGY_BOOK_SYSFS
109define_id_show_func(book_id, "%d");
110static DEVICE_ATTR_RO(book_id);
111define_siblings_read_func(book_siblings, book_cpumask);
112static const BIN_ATTR_RO(book_siblings, CPUMAP_FILE_MAX_BYTES);
113static const BIN_ATTR_RO(book_siblings_list, CPULIST_FILE_MAX_BYTES);
114#endif
115
116#ifdef TOPOLOGY_DRAWER_SYSFS
117define_id_show_func(drawer_id, "%d");
118static DEVICE_ATTR_RO(drawer_id);
119define_siblings_read_func(drawer_siblings, drawer_cpumask);
120static const BIN_ATTR_RO(drawer_siblings, CPUMAP_FILE_MAX_BYTES);
121static const BIN_ATTR_RO(drawer_siblings_list, CPULIST_FILE_MAX_BYTES);
122#endif
123
124static const struct bin_attribute *const bin_attrs[] = {
125	&bin_attr_core_cpus,
126	&bin_attr_core_cpus_list,
127	&bin_attr_thread_siblings,
128	&bin_attr_thread_siblings_list,
129	&bin_attr_core_siblings,
130	&bin_attr_core_siblings_list,
131#ifdef TOPOLOGY_CLUSTER_SYSFS
132	&bin_attr_cluster_cpus,
133	&bin_attr_cluster_cpus_list,
134#endif
135#ifdef TOPOLOGY_DIE_SYSFS
136	&bin_attr_die_cpus,
137	&bin_attr_die_cpus_list,
138#endif
139	&bin_attr_package_cpus,
140	&bin_attr_package_cpus_list,
141#ifdef TOPOLOGY_BOOK_SYSFS
142	&bin_attr_book_siblings,
143	&bin_attr_book_siblings_list,
144#endif
145#ifdef TOPOLOGY_DRAWER_SYSFS
146	&bin_attr_drawer_siblings,
147	&bin_attr_drawer_siblings_list,
148#endif
149	NULL
150};
151
152static struct attribute *default_attrs[] = {
153	&dev_attr_physical_package_id.attr,
154#ifdef TOPOLOGY_DIE_SYSFS
155	&dev_attr_die_id.attr,
156#endif
157#ifdef TOPOLOGY_CLUSTER_SYSFS
158	&dev_attr_cluster_id.attr,
159#endif
160	&dev_attr_core_id.attr,
161#ifdef TOPOLOGY_BOOK_SYSFS
162	&dev_attr_book_id.attr,
163#endif
164#ifdef TOPOLOGY_DRAWER_SYSFS
165	&dev_attr_drawer_id.attr,
166#endif
167	&dev_attr_ppin.attr,
168	NULL
169};
170
171static umode_t topology_is_visible(struct kobject *kobj,
172				   struct attribute *attr, int unused)
173{
174	if (attr == &dev_attr_ppin.attr && !topology_ppin(kobj_to_dev(kobj)->id))
175		return 0;
176
177	return attr->mode;
178}
179
180static const struct attribute_group topology_attr_group = {
181	.attrs = default_attrs,
182	.bin_attrs = bin_attrs,
183	.is_visible = topology_is_visible,
184	.name = "topology"
185};
186
187/* Add/Remove cpu_topology interface for CPU device */
188static int topology_add_dev(unsigned int cpu)
189{
190	struct device *dev = get_cpu_device(cpu);
191
192	return sysfs_create_group(&dev->kobj, &topology_attr_group);
193}
194
195static int topology_remove_dev(unsigned int cpu)
196{
197	struct device *dev = get_cpu_device(cpu);
198
199	sysfs_remove_group(&dev->kobj, &topology_attr_group);
200	return 0;
201}
202
203static int __init topology_sysfs_init(void)
204{
205	return cpuhp_setup_state(CPUHP_TOPOLOGY_PREPARE,
206				 "base/topology:prepare", topology_add_dev,
207				 topology_remove_dev);
208}
209
210device_initcall(topology_sysfs_init);
211
212DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;
213EXPORT_PER_CPU_SYMBOL_GPL(cpu_scale);
214
215void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity)
216{
217	per_cpu(cpu_scale, cpu) = capacity;
218}
219
220static ssize_t cpu_capacity_show(struct device *dev,
221				 struct device_attribute *attr,
222				 char *buf)
223{
224	struct cpu *cpu = container_of(dev, struct cpu, dev);
225
226	return sysfs_emit(buf, "%lu\n", topology_get_cpu_scale(cpu->dev.id));
227}
228
229static DEVICE_ATTR_RO(cpu_capacity);
230
231static int cpu_capacity_sysctl_add(unsigned int cpu)
232{
233	struct device *cpu_dev = get_cpu_device(cpu);
234
235	if (!cpu_dev)
236		return -ENOENT;
237
238	device_create_file(cpu_dev, &dev_attr_cpu_capacity);
239
240	return 0;
241}
242
243static int cpu_capacity_sysctl_remove(unsigned int cpu)
244{
245	struct device *cpu_dev = get_cpu_device(cpu);
246
247	if (!cpu_dev)
248		return -ENOENT;
249
250	device_remove_file(cpu_dev, &dev_attr_cpu_capacity);
251
252	return 0;
253}
254
255static int register_cpu_capacity_sysctl(void)
256{
257	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "topology/cpu-capacity",
258			  cpu_capacity_sysctl_add, cpu_capacity_sysctl_remove);
259
260	return 0;
261}
262subsys_initcall(register_cpu_capacity_sysctl);