1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Extract CPU cache information and expose them via sysfs.
4 *
5 * Copyright IBM Corp. 2012
6 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
7 */
8
9 #include <linux/seq_file.h>
10 #include <linux/cpu.h>
11 #include <linux/cacheinfo.h>
12 #include <asm/facility.h>
13
14 enum {
15 CACHE_SCOPE_NOTEXISTS,
16 CACHE_SCOPE_PRIVATE,
17 CACHE_SCOPE_SHARED,
18 CACHE_SCOPE_RESERVED,
19 };
20
21 enum {
22 CTYPE_SEPARATE,
23 CTYPE_DATA,
24 CTYPE_INSTRUCTION,
25 CTYPE_UNIFIED,
26 };
27
28 enum {
29 EXTRACT_TOPOLOGY,
30 EXTRACT_LINE_SIZE,
31 EXTRACT_SIZE,
32 EXTRACT_ASSOCIATIVITY,
33 };
34
35 enum {
36 CACHE_TI_UNIFIED = 0,
37 CACHE_TI_DATA = 0,
38 CACHE_TI_INSTRUCTION,
39 };
40
41 struct cache_info {
42 unsigned char : 4;
43 unsigned char scope : 2;
44 unsigned char type : 2;
45 };
46
47 #define CACHE_MAX_LEVEL 8
48 union cache_topology {
49 struct cache_info ci[CACHE_MAX_LEVEL];
50 unsigned long long raw;
51 };
52
53 static const char * const cache_type_string[] = {
54 "",
55 "Instruction",
56 "Data",
57 "",
58 "Unified",
59 };
60
61 static const enum cache_type cache_type_map[] = {
62 [CTYPE_SEPARATE] = CACHE_TYPE_SEPARATE,
63 [CTYPE_DATA] = CACHE_TYPE_DATA,
64 [CTYPE_INSTRUCTION] = CACHE_TYPE_INST,
65 [CTYPE_UNIFIED] = CACHE_TYPE_UNIFIED,
66 };
67
show_cacheinfo(struct seq_file * m)68 void show_cacheinfo(struct seq_file *m)
69 {
70 struct cpu_cacheinfo *this_cpu_ci;
71 struct cacheinfo *cache;
72 int idx;
73
74 if (!test_facility(34))
75 return;
76 this_cpu_ci = get_cpu_cacheinfo(cpumask_any(cpu_online_mask));
77 for (idx = 0; idx < this_cpu_ci->num_leaves; idx++) {
78 cache = this_cpu_ci->info_list + idx;
79 seq_printf(m, "cache%-11d: ", idx);
80 seq_printf(m, "level=%d ", cache->level);
81 seq_printf(m, "type=%s ", cache_type_string[cache->type]);
82 seq_printf(m, "scope=%s ",
83 cache->disable_sysfs ? "Shared" : "Private");
84 seq_printf(m, "size=%dK ", cache->size >> 10);
85 seq_printf(m, "line_size=%u ", cache->coherency_line_size);
86 seq_printf(m, "associativity=%d", cache->ways_of_associativity);
87 seq_puts(m, "\n");
88 }
89 }
90
get_cache_type(struct cache_info * ci,int level)91 static inline enum cache_type get_cache_type(struct cache_info *ci, int level)
92 {
93 if (level >= CACHE_MAX_LEVEL)
94 return CACHE_TYPE_NOCACHE;
95 ci += level;
96 if (ci->scope != CACHE_SCOPE_SHARED && ci->scope != CACHE_SCOPE_PRIVATE)
97 return CACHE_TYPE_NOCACHE;
98 return cache_type_map[ci->type];
99 }
100
ecag(int ai,int li,int ti)101 static inline unsigned long ecag(int ai, int li, int ti)
102 {
103 return __ecag(ECAG_CACHE_ATTRIBUTE, ai << 4 | li << 1 | ti);
104 }
105
ci_leaf_init(struct cacheinfo * this_leaf,int private,enum cache_type type,unsigned int level,int cpu)106 static void ci_leaf_init(struct cacheinfo *this_leaf, int private,
107 enum cache_type type, unsigned int level, int cpu)
108 {
109 int ti, num_sets;
110
111 if (type == CACHE_TYPE_INST)
112 ti = CACHE_TI_INSTRUCTION;
113 else
114 ti = CACHE_TI_UNIFIED;
115 this_leaf->level = level + 1;
116 this_leaf->type = type;
117 this_leaf->coherency_line_size = ecag(EXTRACT_LINE_SIZE, level, ti);
118 this_leaf->ways_of_associativity = ecag(EXTRACT_ASSOCIATIVITY, level, ti);
119 this_leaf->size = ecag(EXTRACT_SIZE, level, ti);
120 num_sets = this_leaf->size / this_leaf->coherency_line_size;
121 num_sets /= this_leaf->ways_of_associativity;
122 this_leaf->number_of_sets = num_sets;
123 cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
124 if (!private)
125 this_leaf->disable_sysfs = true;
126 }
127
init_cache_level(unsigned int cpu)128 int init_cache_level(unsigned int cpu)
129 {
130 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
131 unsigned int level = 0, leaves = 0;
132 union cache_topology ct;
133 enum cache_type ctype;
134
135 if (!test_facility(34))
136 return -EOPNOTSUPP;
137 if (!this_cpu_ci)
138 return -EINVAL;
139 ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0);
140 do {
141 ctype = get_cache_type(&ct.ci[0], level);
142 if (ctype == CACHE_TYPE_NOCACHE)
143 break;
144 /* Separate instruction and data caches */
145 leaves += (ctype == CACHE_TYPE_SEPARATE) ? 2 : 1;
146 } while (++level < CACHE_MAX_LEVEL);
147 this_cpu_ci->num_levels = level;
148 this_cpu_ci->num_leaves = leaves;
149 return 0;
150 }
151
populate_cache_leaves(unsigned int cpu)152 int populate_cache_leaves(unsigned int cpu)
153 {
154 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
155 struct cacheinfo *this_leaf = this_cpu_ci->info_list;
156 unsigned int level, idx, pvt;
157 union cache_topology ct;
158 enum cache_type ctype;
159
160 if (!test_facility(34))
161 return -EOPNOTSUPP;
162 ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0);
163 for (idx = 0, level = 0; level < this_cpu_ci->num_levels &&
164 idx < this_cpu_ci->num_leaves; idx++, level++) {
165 if (!this_leaf)
166 return -EINVAL;
167 pvt = (ct.ci[level].scope == CACHE_SCOPE_PRIVATE) ? 1 : 0;
168 ctype = get_cache_type(&ct.ci[0], level);
169 if (ctype == CACHE_TYPE_SEPARATE) {
170 ci_leaf_init(this_leaf++, pvt, CACHE_TYPE_DATA, level, cpu);
171 ci_leaf_init(this_leaf++, pvt, CACHE_TYPE_INST, level, cpu);
172 } else {
173 ci_leaf_init(this_leaf++, pvt, ctype, level, cpu);
174 }
175 }
176 return 0;
177 }
178