arch/s390/kernel/cache.c

   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 }