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)					\
18 static 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)					\
25 static ssize_t name##_read(struct file *file, struct kobject *kobj,		\
26 			   struct bin_attribute *attr, char *buf,		\
27 			   loff_t off, size_t count)				\
28 {										\
29 	struct device *dev = kobj_to_dev(kobj);                                 \
30 										\
31 	return cpumap_print_bitmask_to_buf(buf, topology_##mask(dev->id),	\
32 					   off, count);                         \
33 }										\
34 										\
35 static ssize_t name##_list_read(struct file *file, struct kobject *kobj,	\
36 				struct bin_attribute *attr, char *buf,		\
37 				loff_t off, size_t count)			\
38 {										\
39 	struct device *dev = kobj_to_dev(kobj);					\
40 										\
41 	return cpumap_print_list_to_buf(buf, topology_##mask(dev->id),		\
42 					off, count);				\
43 }
44 
45 define_id_show_func(physical_package_id, "%d");
46 static DEVICE_ATTR_RO(physical_package_id);
47 
48 #ifdef TOPOLOGY_DIE_SYSFS
49 define_id_show_func(die_id, "%d");
50 static DEVICE_ATTR_RO(die_id);
51 #endif
52 
53 #ifdef TOPOLOGY_CLUSTER_SYSFS
54 define_id_show_func(cluster_id, "%d");
55 static DEVICE_ATTR_RO(cluster_id);
56 #endif
57 
58 define_id_show_func(core_id, "%d");
59 static DEVICE_ATTR_RO(core_id);
60 
61 define_id_show_func(ppin, "0x%llx");
62 static DEVICE_ATTR_ADMIN_RO(ppin);
63 
64 define_siblings_read_func(thread_siblings, sibling_cpumask);
65 static BIN_ATTR_RO(thread_siblings, CPUMAP_FILE_MAX_BYTES);
66 static BIN_ATTR_RO(thread_siblings_list, CPULIST_FILE_MAX_BYTES);
67 
68 define_siblings_read_func(core_cpus, sibling_cpumask);
69 static BIN_ATTR_RO(core_cpus, CPUMAP_FILE_MAX_BYTES);
70 static BIN_ATTR_RO(core_cpus_list, CPULIST_FILE_MAX_BYTES);
71 
72 define_siblings_read_func(core_siblings, core_cpumask);
73 static BIN_ATTR_RO(core_siblings, CPUMAP_FILE_MAX_BYTES);
74 static BIN_ATTR_RO(core_siblings_list, CPULIST_FILE_MAX_BYTES);
75 
76 #ifdef TOPOLOGY_CLUSTER_SYSFS
77 define_siblings_read_func(cluster_cpus, cluster_cpumask);
78 static BIN_ATTR_RO(cluster_cpus, CPUMAP_FILE_MAX_BYTES);
79 static BIN_ATTR_RO(cluster_cpus_list, CPULIST_FILE_MAX_BYTES);
80 #endif
81 
82 #ifdef TOPOLOGY_DIE_SYSFS
83 define_siblings_read_func(die_cpus, die_cpumask);
84 static BIN_ATTR_RO(die_cpus, CPUMAP_FILE_MAX_BYTES);
85 static BIN_ATTR_RO(die_cpus_list, CPULIST_FILE_MAX_BYTES);
86 #endif
87 
88 define_siblings_read_func(package_cpus, core_cpumask);
89 static BIN_ATTR_RO(package_cpus, CPUMAP_FILE_MAX_BYTES);
90 static BIN_ATTR_RO(package_cpus_list, CPULIST_FILE_MAX_BYTES);
91 
92 #ifdef TOPOLOGY_BOOK_SYSFS
93 define_id_show_func(book_id, "%d");
94 static DEVICE_ATTR_RO(book_id);
95 define_siblings_read_func(book_siblings, book_cpumask);
96 static BIN_ATTR_RO(book_siblings, CPUMAP_FILE_MAX_BYTES);
97 static BIN_ATTR_RO(book_siblings_list, CPULIST_FILE_MAX_BYTES);
98 #endif
99 
100 #ifdef TOPOLOGY_DRAWER_SYSFS
101 define_id_show_func(drawer_id, "%d");
102 static DEVICE_ATTR_RO(drawer_id);
103 define_siblings_read_func(drawer_siblings, drawer_cpumask);
104 static BIN_ATTR_RO(drawer_siblings, CPUMAP_FILE_MAX_BYTES);
105 static BIN_ATTR_RO(drawer_siblings_list, CPULIST_FILE_MAX_BYTES);
106 #endif
107 
108 static struct bin_attribute *bin_attrs[] = {
109 	&bin_attr_core_cpus,
110 	&bin_attr_core_cpus_list,
111 	&bin_attr_thread_siblings,
112 	&bin_attr_thread_siblings_list,
113 	&bin_attr_core_siblings,
114 	&bin_attr_core_siblings_list,
115 #ifdef TOPOLOGY_CLUSTER_SYSFS
116 	&bin_attr_cluster_cpus,
117 	&bin_attr_cluster_cpus_list,
118 #endif
119 #ifdef TOPOLOGY_DIE_SYSFS
120 	&bin_attr_die_cpus,
121 	&bin_attr_die_cpus_list,
122 #endif
123 	&bin_attr_package_cpus,
124 	&bin_attr_package_cpus_list,
125 #ifdef TOPOLOGY_BOOK_SYSFS
126 	&bin_attr_book_siblings,
127 	&bin_attr_book_siblings_list,
128 #endif
129 #ifdef TOPOLOGY_DRAWER_SYSFS
130 	&bin_attr_drawer_siblings,
131 	&bin_attr_drawer_siblings_list,
132 #endif
133 	NULL
134 };
135 
136 static struct attribute *default_attrs[] = {
137 	&dev_attr_physical_package_id.attr,
138 #ifdef TOPOLOGY_DIE_SYSFS
139 	&dev_attr_die_id.attr,
140 #endif
141 #ifdef TOPOLOGY_CLUSTER_SYSFS
142 	&dev_attr_cluster_id.attr,
143 #endif
144 	&dev_attr_core_id.attr,
145 #ifdef TOPOLOGY_BOOK_SYSFS
146 	&dev_attr_book_id.attr,
147 #endif
148 #ifdef TOPOLOGY_DRAWER_SYSFS
149 	&dev_attr_drawer_id.attr,
150 #endif
151 	&dev_attr_ppin.attr,
152 	NULL
153 };
154 
topology_is_visible(struct kobject * kobj,struct attribute * attr,int unused)155 static umode_t topology_is_visible(struct kobject *kobj,
156 				   struct attribute *attr, int unused)
157 {
158 	if (attr == &dev_attr_ppin.attr && !topology_ppin(kobj_to_dev(kobj)->id))
159 		return 0;
160 
161 	return attr->mode;
162 }
163 
164 static const struct attribute_group topology_attr_group = {
165 	.attrs = default_attrs,
166 	.bin_attrs = bin_attrs,
167 	.is_visible = topology_is_visible,
168 	.name = "topology"
169 };
170 
171 /* Add/Remove cpu_topology interface for CPU device */
topology_add_dev(unsigned int cpu)172 static int topology_add_dev(unsigned int cpu)
173 {
174 	struct device *dev = get_cpu_device(cpu);
175 
176 	return sysfs_create_group(&dev->kobj, &topology_attr_group);
177 }
178 
topology_remove_dev(unsigned int cpu)179 static int topology_remove_dev(unsigned int cpu)
180 {
181 	struct device *dev = get_cpu_device(cpu);
182 
183 	sysfs_remove_group(&dev->kobj, &topology_attr_group);
184 	return 0;
185 }
186 
topology_sysfs_init(void)187 static int __init topology_sysfs_init(void)
188 {
189 	return cpuhp_setup_state(CPUHP_TOPOLOGY_PREPARE,
190 				 "base/topology:prepare", topology_add_dev,
191 				 topology_remove_dev);
192 }
193 
194 device_initcall(topology_sysfs_init);
195