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 get_online_cpus(); 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 put_online_cpus(); 90 } 91 92 static inline enum cache_type get_cache_type(struct cache_info *ci, int level) 93 { 94 if (level >= CACHE_MAX_LEVEL) 95 return CACHE_TYPE_NOCACHE; 96 ci += level; 97 if (ci->scope != CACHE_SCOPE_SHARED && ci->scope != CACHE_SCOPE_PRIVATE) 98 return CACHE_TYPE_NOCACHE; 99 return cache_type_map[ci->type]; 100 } 101 102 static inline unsigned long ecag(int ai, int li, int ti) 103 { 104 unsigned long cmd, val; 105 106 cmd = ai << 4 | li << 1 | ti; 107 asm volatile(".insn rsy,0xeb000000004c,%0,0,0(%1)" /* ecag */ 108 : "=d" (val) : "a" (cmd)); 109 return val; 110 } 111 112 static void ci_leaf_init(struct cacheinfo *this_leaf, int private, 113 enum cache_type type, unsigned int level, int cpu) 114 { 115 int ti, num_sets; 116 117 if (type == CACHE_TYPE_INST) 118 ti = CACHE_TI_INSTRUCTION; 119 else 120 ti = CACHE_TI_UNIFIED; 121 this_leaf->level = level + 1; 122 this_leaf->type = type; 123 this_leaf->coherency_line_size = ecag(EXTRACT_LINE_SIZE, level, ti); 124 this_leaf->ways_of_associativity = ecag(EXTRACT_ASSOCIATIVITY, level, ti); 125 this_leaf->size = ecag(EXTRACT_SIZE, level, ti); 126 num_sets = this_leaf->size / this_leaf->coherency_line_size; 127 num_sets /= this_leaf->ways_of_associativity; 128 this_leaf->number_of_sets = num_sets; 129 cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map); 130 if (!private) 131 this_leaf->disable_sysfs = true; 132 } 133 134 int init_cache_level(unsigned int cpu) 135 { 136 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); 137 unsigned int level = 0, leaves = 0; 138 union cache_topology ct; 139 enum cache_type ctype; 140 141 if (!test_facility(34)) 142 return -EOPNOTSUPP; 143 if (!this_cpu_ci) 144 return -EINVAL; 145 ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0); 146 do { 147 ctype = get_cache_type(&ct.ci[0], level); 148 if (ctype == CACHE_TYPE_NOCACHE) 149 break; 150 /* Separate instruction and data caches */ 151 leaves += (ctype == CACHE_TYPE_SEPARATE) ? 2 : 1; 152 } while (++level < CACHE_MAX_LEVEL); 153 this_cpu_ci->num_levels = level; 154 this_cpu_ci->num_leaves = leaves; 155 return 0; 156 } 157 158 int populate_cache_leaves(unsigned int cpu) 159 { 160 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); 161 struct cacheinfo *this_leaf = this_cpu_ci->info_list; 162 unsigned int level, idx, pvt; 163 union cache_topology ct; 164 enum cache_type ctype; 165 166 if (!test_facility(34)) 167 return -EOPNOTSUPP; 168 ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0); 169 for (idx = 0, level = 0; level < this_cpu_ci->num_levels && 170 idx < this_cpu_ci->num_leaves; idx++, level++) { 171 if (!this_leaf) 172 return -EINVAL; 173 pvt = (ct.ci[level].scope == CACHE_SCOPE_PRIVATE) ? 1 : 0; 174 ctype = get_cache_type(&ct.ci[0], level); 175 if (ctype == CACHE_TYPE_SEPARATE) { 176 ci_leaf_init(this_leaf++, pvt, CACHE_TYPE_DATA, level, cpu); 177 ci_leaf_init(this_leaf++, pvt, CACHE_TYPE_INST, level, cpu); 178 } else { 179 ci_leaf_init(this_leaf++, pvt, ctype, level, cpu); 180 } 181 } 182 return 0; 183 } 184