linux/arch/s390/kernel/cache.c
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   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
  13enum {
  14        CACHE_SCOPE_NOTEXISTS,
  15        CACHE_SCOPE_PRIVATE,
  16        CACHE_SCOPE_SHARED,
  17        CACHE_SCOPE_RESERVED,
  18};
  19
  20enum {
  21        CTYPE_SEPARATE,
  22        CTYPE_DATA,
  23        CTYPE_INSTRUCTION,
  24        CTYPE_UNIFIED,
  25};
  26
  27enum {
  28        EXTRACT_TOPOLOGY,
  29        EXTRACT_LINE_SIZE,
  30        EXTRACT_SIZE,
  31        EXTRACT_ASSOCIATIVITY,
  32};
  33
  34enum {
  35        CACHE_TI_UNIFIED = 0,
  36        CACHE_TI_DATA = 0,
  37        CACHE_TI_INSTRUCTION,
  38};
  39
  40struct cache_info {
  41        unsigned char       : 4;
  42        unsigned char scope : 2;
  43        unsigned char type  : 2;
  44};
  45
  46#define CACHE_MAX_LEVEL 8
  47union cache_topology {
  48        struct cache_info ci[CACHE_MAX_LEVEL];
  49        unsigned long long raw;
  50};
  51
  52static const char * const cache_type_string[] = {
  53        "",
  54        "Instruction",
  55        "Data",
  56        "",
  57        "Unified",
  58};
  59
  60static 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
  67void 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
  90static 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
 100static inline unsigned long ecag(int ai, int li, int ti)
 101{
 102        return __ecag(ECAG_CACHE_ATTRIBUTE, ai << 4 | li << 1 | ti);
 103}
 104
 105static 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
 127int 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
 151int 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}
 177