arch/s390/kernel/cache.c

   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  *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
   7  */
   8
   9 #include <linux/seq_file.h>
  10 #include <linux/cpu.h>
  11 #include <linux/cacheinfo.h>
  12 #include <asm/facility.h>
  13
  14 enum {
  15         CACHE_SCOPE_NOTEXISTS,
  16         CACHE_SCOPE_PRIVATE,
  17         CACHE_SCOPE_SHARED,
  18         CACHE_SCOPE_RESERVED,
  19 };
  20
  21 enum {
  22         CTYPE_SEPARATE,
  23         CTYPE_DATA,
  24         CTYPE_INSTRUCTION,
  25         CTYPE_UNIFIED,
  26 };
  27
  28 enum {
  29         EXTRACT_TOPOLOGY,
  30         EXTRACT_LINE_SIZE,
  31         EXTRACT_SIZE,
  32         EXTRACT_ASSOCIATIVITY,
  33 };
  34
  35 enum {
  36         CACHE_TI_UNIFIED = 0,
  37         CACHE_TI_DATA = 0,
  38         CACHE_TI_INSTRUCTION,
  39 };
  40
  41 struct cache_info {
  42         unsigned char       : 4;
  43         unsigned char scope : 2;
  44         unsigned char type  : 2;
  45 };
  46
  47 #define CACHE_MAX_LEVEL 8
  48 union cache_topology {
  49         struct cache_info ci[CACHE_MAX_LEVEL];
  50         unsigned long long raw;
  51 };
  52
  53 static const char * const cache_type_string[] = {
  54         "",
  55         "Instruction",
  56         "Data",
  57         "",
  58         "Unified",
  59 };
  60
  61 static const enum cache_type cache_type_map[] = {
  62         [CTYPE_SEPARATE] = CACHE_TYPE_SEPARATE,
  63         [CTYPE_DATA] = CACHE_TYPE_DATA,
  64         [CTYPE_INSTRUCTION] = CACHE_TYPE_INST,
  65         [CTYPE_UNIFIED] = CACHE_TYPE_UNIFIED,
  66 };
  67
  68 void show_cacheinfo(struct seq_file *m)
  69 {
  70         struct cpu_cacheinfo *this_cpu_ci;
  71         struct cacheinfo *cache;
  72         int idx;
  73
  74         if (!test_facility(34))
  75                 return;
  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 }
  90
  91 static inline enum cache_type get_cache_type(struct cache_info *ci, int level)
  92 {
  93         if (level >= CACHE_MAX_LEVEL)
  94                 return CACHE_TYPE_NOCACHE;
  95         ci += level;
  96         if (ci->scope != CACHE_SCOPE_SHARED && ci->scope != CACHE_SCOPE_PRIVATE)
  97                 return CACHE_TYPE_NOCACHE;
  98         return cache_type_map[ci->type];
  99 }
 100
 101 static inline unsigned long ecag(int ai, int li, int ti)
 102 {
 103         return __ecag(ECAG_CACHE_ATTRIBUTE, ai << 4 | li << 1 | ti);
 104 }
 105
 106 static void ci_leaf_init(struct cacheinfo *this_leaf, int private,
 107                          enum cache_type type, unsigned int level, int cpu)
 108 {
 109         int ti, num_sets;
 110
 111         if (type == CACHE_TYPE_INST)
 112                 ti = CACHE_TI_INSTRUCTION;
 113         else
 114                 ti = CACHE_TI_UNIFIED;
 115         this_leaf->level = level + 1;
 116         this_leaf->type = type;
 117         this_leaf->coherency_line_size = ecag(EXTRACT_LINE_SIZE, level, ti);
 118         this_leaf->ways_of_associativity = ecag(EXTRACT_ASSOCIATIVITY, level, ti);
 119         this_leaf->size = ecag(EXTRACT_SIZE, level, ti);
 120         num_sets = this_leaf->size / this_leaf->coherency_line_size;
 121         num_sets /= this_leaf->ways_of_associativity;
 122         this_leaf->number_of_sets = num_sets;
 123         cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
 124         if (!private)
 125                 this_leaf->disable_sysfs = true;
 126 }
 127
 128 int init_cache_level(unsigned int cpu)
 129 {
 130         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 131         unsigned int level = 0, leaves = 0;
 132         union cache_topology ct;
 133         enum cache_type ctype;
 134
 135         if (!test_facility(34))
 136                 return -EOPNOTSUPP;
 137         if (!this_cpu_ci)
 138                 return -EINVAL;
 139         ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0);
 140         do {
 141                 ctype = get_cache_type(&ct.ci[0], level);
 142                 if (ctype == CACHE_TYPE_NOCACHE)
 143                         break;
 144                 /* Separate instruction and data caches */
 145                 leaves += (ctype == CACHE_TYPE_SEPARATE) ? 2 : 1;
 146         } while (++level < CACHE_MAX_LEVEL);
 147         this_cpu_ci->num_levels = level;
 148         this_cpu_ci->num_leaves = leaves;
 149         return 0;
 150 }
 151
 152 int populate_cache_leaves(unsigned int cpu)
 153 {
 154         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 155         struct cacheinfo *this_leaf = this_cpu_ci->info_list;
 156         unsigned int level, idx, pvt;
 157         union cache_topology ct;
 158         enum cache_type ctype;
 159
 160         if (!test_facility(34))
 161                 return -EOPNOTSUPP;
 162         ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0);
 163         for (idx = 0, level = 0; level < this_cpu_ci->num_levels &&
 164              idx < this_cpu_ci->num_leaves; idx++, level++) {
 165                 if (!this_leaf)
 166                         return -EINVAL;
 167                 pvt = (ct.ci[level].scope == CACHE_SCOPE_PRIVATE) ? 1 : 0;
 168                 ctype = get_cache_type(&ct.ci[0], level);
 169                 if (ctype == CACHE_TYPE_SEPARATE) {
 170                         ci_leaf_init(this_leaf++, pvt, CACHE_TYPE_DATA, level, cpu);
 171                         ci_leaf_init(this_leaf++, pvt, CACHE_TYPE_INST, level, cpu);
 172                 } else {
 173                         ci_leaf_init(this_leaf++, pvt, ctype, level, cpu);
 174                 }
 175         }
 176         return 0;
 177 }