1 /* 2 * Extract CPU cache information and expose them via sysfs. 3 * 4 * Copyright IBM Corp. 2012 5 * Author(s): Heiko Carstens <[email protected]> 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 get_online_cpus(); 74 this_cpu_ci = get_cpu_cacheinfo(cpumask_any(cpu_online_mask)); 75 for (idx = 0; idx < this_cpu_ci->num_leaves; idx++) { 76 cache = this_cpu_ci->info_list + idx; 77 seq_printf(m, "cache%-11d: ", idx); 78 seq_printf(m, "level=%d ", cache->level); 79 seq_printf(m, "type=%s ", cache_type_string[cache->type]); 80 seq_printf(m, "scope=%s ", 81 cache->disable_sysfs ? "Shared" : "Private"); 82 seq_printf(m, "size=%dK ", cache->size >> 10); 83 seq_printf(m, "line_size=%u ", cache->coherency_line_size); 84 seq_printf(m, "associativity=%d", cache->ways_of_associativity); 85 seq_puts(m, "\n"); 86 } 87 put_online_cpus(); 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 95 ci += level; 96 97 if (ci->scope != CACHE_SCOPE_SHARED && ci->scope != CACHE_SCOPE_PRIVATE) 98 return CACHE_TYPE_NOCACHE; 99 100 return cache_type_map[ci->type]; 101 } 102 103 static inline unsigned long ecag(int ai, int li, int ti) 104 { 105 unsigned long cmd, val; 106 107 cmd = ai << 4 | li << 1 | ti; 108 asm volatile(".insn rsy,0xeb000000004c,%0,0,0(%1)" /* ecag */ 109 : "=d" (val) : "a" (cmd)); 110 return val; 111 } 112 113 static void ci_leaf_init(struct cacheinfo *this_leaf, int private, 114 enum cache_type type, unsigned int level) 115 { 116 int ti, num_sets; 117 int cpu = smp_processor_id(); 118 119 if (type == CACHE_TYPE_INST) 120 ti = CACHE_TI_INSTRUCTION; 121 else 122 ti = CACHE_TI_UNIFIED; 123 124 this_leaf->level = level + 1; 125 this_leaf->type = type; 126 this_leaf->coherency_line_size = ecag(EXTRACT_LINE_SIZE, level, ti); 127 this_leaf->ways_of_associativity = ecag(EXTRACT_ASSOCIATIVITY, 128 level, ti); 129 this_leaf->size = ecag(EXTRACT_SIZE, level, ti); 130 131 num_sets = this_leaf->size / this_leaf->coherency_line_size; 132 num_sets /= this_leaf->ways_of_associativity; 133 this_leaf->number_of_sets = num_sets; 134 cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map); 135 if (!private) 136 this_leaf->disable_sysfs = true; 137 } 138 139 int init_cache_level(unsigned int cpu) 140 { 141 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); 142 unsigned int level = 0, leaves = 0; 143 union cache_topology ct; 144 enum cache_type ctype; 145 146 if (!this_cpu_ci) 147 return -EINVAL; 148 149 ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0); 150 do { 151 ctype = get_cache_type(&ct.ci[0], level); 152 if (ctype == CACHE_TYPE_NOCACHE) 153 break; 154 /* Separate instruction and data caches */ 155 leaves += (ctype == CACHE_TYPE_SEPARATE) ? 2 : 1; 156 } while (++level < CACHE_MAX_LEVEL); 157 158 this_cpu_ci->num_levels = level; 159 this_cpu_ci->num_leaves = leaves; 160 161 return 0; 162 } 163 164 int populate_cache_leaves(unsigned int cpu) 165 { 166 unsigned int level, idx, pvt; 167 union cache_topology ct; 168 enum cache_type ctype; 169 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); 170 struct cacheinfo *this_leaf = this_cpu_ci->info_list; 171 172 ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0); 173 for (idx = 0, level = 0; level < this_cpu_ci->num_levels && 174 idx < this_cpu_ci->num_leaves; idx++, level++) { 175 if (!this_leaf) 176 return -EINVAL; 177 178 pvt = (ct.ci[level].scope == CACHE_SCOPE_PRIVATE) ? 1 : 0; 179 ctype = get_cache_type(&ct.ci[0], level); 180 if (ctype == CACHE_TYPE_SEPARATE) { 181 ci_leaf_init(this_leaf++, pvt, CACHE_TYPE_DATA, level); 182 ci_leaf_init(this_leaf++, pvt, CACHE_TYPE_INST, level); 183 } else { 184 ci_leaf_init(this_leaf++, pvt, ctype, level); 185 } 186 } 187 return 0; 188 } 189