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 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 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 } 100 101 static inline unsigned long ecag(int ai, int li, int ti) 102 { 103 return __ecag(ECAG_CACHE_ATTRIBUTE, ai << 4 | li << 1 | ti); 104 } 105 106 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 } 127 128 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 } 151 152 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