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