1 /* 2 * Extract CPU cache information and expose them via sysfs. 3 * 4 * Copyright IBM Corp. 2012 5 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com> 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 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 if (!test_facility(34)) 74 return; 75 this_cpu_ci = get_cpu_cacheinfo(cpumask_any(cpu_online_mask)); 76 for (idx = 0; idx < this_cpu_ci->num_leaves; idx++) { 77 cache = this_cpu_ci->info_list + idx; 78 seq_printf(m, "cache%-11d: ", idx); 79 seq_printf(m, "level=%d ", cache->level); 80 seq_printf(m, "type=%s ", cache_type_string[cache->type]); 81 seq_printf(m, "scope=%s ", 82 cache->disable_sysfs ? "Shared" : "Private"); 83 seq_printf(m, "size=%dK ", cache->size >> 10); 84 seq_printf(m, "line_size=%u ", cache->coherency_line_size); 85 seq_printf(m, "associativity=%d", cache->ways_of_associativity); 86 seq_puts(m, "\n"); 87 } 88 } 89 90 static inline enum cache_type get_cache_type(struct cache_info *ci, int level) 91 { 92 if (level >= CACHE_MAX_LEVEL) 93 return CACHE_TYPE_NOCACHE; 94 ci += level; 95 if (ci->scope != CACHE_SCOPE_SHARED && ci->scope != CACHE_SCOPE_PRIVATE) 96 return CACHE_TYPE_NOCACHE; 97 return cache_type_map[ci->type]; 98 } 99 100 static inline unsigned long ecag(int ai, int li, int ti) 101 { 102 return __ecag(ECAG_CACHE_ATTRIBUTE, ai << 4 | li << 1 | ti); 103 } 104 105 static void ci_leaf_init(struct cacheinfo *this_leaf, int private, 106 enum cache_type type, unsigned int level, int cpu) 107 { 108 int ti, num_sets; 109 110 if (type == CACHE_TYPE_INST) 111 ti = CACHE_TI_INSTRUCTION; 112 else 113 ti = CACHE_TI_UNIFIED; 114 this_leaf->level = level + 1; 115 this_leaf->type = type; 116 this_leaf->coherency_line_size = ecag(EXTRACT_LINE_SIZE, level, ti); 117 this_leaf->ways_of_associativity = ecag(EXTRACT_ASSOCIATIVITY, level, ti); 118 this_leaf->size = ecag(EXTRACT_SIZE, level, ti); 119 num_sets = this_leaf->size / this_leaf->coherency_line_size; 120 num_sets /= this_leaf->ways_of_associativity; 121 this_leaf->number_of_sets = num_sets; 122 cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map); 123 if (!private) 124 this_leaf->disable_sysfs = true; 125 } 126 127 int init_cache_level(unsigned int cpu) 128 { 129 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); 130 unsigned int level = 0, leaves = 0; 131 union cache_topology ct; 132 enum cache_type ctype; 133 134 if (!test_facility(34)) 135 return -EOPNOTSUPP; 136 if (!this_cpu_ci) 137 return -EINVAL; 138 ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0); 139 do { 140 ctype = get_cache_type(&ct.ci[0], level); 141 if (ctype == CACHE_TYPE_NOCACHE) 142 break; 143 /* Separate instruction and data caches */ 144 leaves += (ctype == CACHE_TYPE_SEPARATE) ? 2 : 1; 145 } while (++level < CACHE_MAX_LEVEL); 146 this_cpu_ci->num_levels = level; 147 this_cpu_ci->num_leaves = leaves; 148 return 0; 149 } 150 151 int populate_cache_leaves(unsigned int cpu) 152 { 153 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); 154 struct cacheinfo *this_leaf = this_cpu_ci->info_list; 155 unsigned int level, idx, pvt; 156 union cache_topology ct; 157 enum cache_type ctype; 158 159 if (!test_facility(34)) 160 return -EOPNOTSUPP; 161 ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0); 162 for (idx = 0, level = 0; level < this_cpu_ci->num_levels && 163 idx < this_cpu_ci->num_leaves; idx++, level++) { 164 if (!this_leaf) 165 return -EINVAL; 166 pvt = (ct.ci[level].scope == CACHE_SCOPE_PRIVATE) ? 1 : 0; 167 ctype = get_cache_type(&ct.ci[0], level); 168 if (ctype == CACHE_TYPE_SEPARATE) { 169 ci_leaf_init(this_leaf++, pvt, CACHE_TYPE_DATA, level, cpu); 170 ci_leaf_init(this_leaf++, pvt, CACHE_TYPE_INST, level, cpu); 171 } else { 172 ci_leaf_init(this_leaf++, pvt, ctype, level, cpu); 173 } 174 } 175 return 0; 176 } 177