linux/arch/s390/kernel/cache.c
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   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
  14enum {
  15        CACHE_SCOPE_NOTEXISTS,
  16        CACHE_SCOPE_PRIVATE,
  17        CACHE_SCOPE_SHARED,
  18        CACHE_SCOPE_RESERVED,
  19};
  20
  21enum {
  22        CTYPE_SEPARATE,
  23        CTYPE_DATA,
  24        CTYPE_INSTRUCTION,
  25        CTYPE_UNIFIED,
  26};
  27
  28enum {
  29        EXTRACT_TOPOLOGY,
  30        EXTRACT_LINE_SIZE,
  31        EXTRACT_SIZE,
  32        EXTRACT_ASSOCIATIVITY,
  33};
  34
  35enum {
  36        CACHE_TI_UNIFIED = 0,
  37        CACHE_TI_DATA = 0,
  38        CACHE_TI_INSTRUCTION,
  39};
  40
  41struct cache_info {
  42        unsigned char       : 4;
  43        unsigned char scope : 2;
  44        unsigned char type  : 2;
  45};
  46
  47#define CACHE_MAX_LEVEL 8
  48union cache_topology {
  49        struct cache_info ci[CACHE_MAX_LEVEL];
  50        unsigned long long raw;
  51};
  52
  53static const char * const cache_type_string[] = {
  54        "",
  55        "Instruction",
  56        "Data",
  57        "",
  58        "Unified",
  59};
  60
  61static 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
  68void 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
  91static 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
 101static inline unsigned long ecag(int ai, int li, int ti)
 102{
 103        return __ecag(ECAG_CACHE_ATTRIBUTE, ai << 4 | li << 1 | ti);
 104}
 105
 106static 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
 128int 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
 152int 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}
 178