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/notifier.h>
   9 #include <linux/seq_file.h>
  10 #include <linux/init.h>
  11 #include <linux/list.h>
  12 #include <linux/slab.h>
  13 #include <linux/cpu.h>
  14 #include <asm/facility.h>
  15
  16 struct cache {
  17         unsigned long size;
  18         unsigned int line_size;
  19         unsigned int associativity;
  20         unsigned int nr_sets;
  21         unsigned int level   : 3;
  22         unsigned int type    : 2;
  23         unsigned int private : 1;
  24         struct list_head list;
  25 };
  26
  27 struct cache_dir {
  28         struct kobject *kobj;
  29         struct cache_index_dir *index;
  30 };
  31
  32 struct cache_index_dir {
  33         struct kobject kobj;
  34         int cpu;
  35         struct cache *cache;
  36         struct cache_index_dir *next;
  37 };
  38
  39 enum {
  40         CACHE_SCOPE_NOTEXISTS,
  41         CACHE_SCOPE_PRIVATE,
  42         CACHE_SCOPE_SHARED,
  43         CACHE_SCOPE_RESERVED,
  44 };
  45
  46 enum {
  47         CACHE_TYPE_SEPARATE,
  48         CACHE_TYPE_DATA,
  49         CACHE_TYPE_INSTRUCTION,
  50         CACHE_TYPE_UNIFIED,
  51 };
  52
  53 enum {
  54         EXTRACT_TOPOLOGY,
  55         EXTRACT_LINE_SIZE,
  56         EXTRACT_SIZE,
  57         EXTRACT_ASSOCIATIVITY,
  58 };
  59
  60 enum {
  61         CACHE_TI_UNIFIED = 0,
  62         CACHE_TI_DATA = 0,
  63         CACHE_TI_INSTRUCTION,
  64 };
  65
  66 struct cache_info {
  67         unsigned char       : 4;
  68         unsigned char scope : 2;
  69         unsigned char type  : 2;
  70 };
  71
  72 #define CACHE_MAX_LEVEL 8
  73
  74 union cache_topology {
  75         struct cache_info ci[CACHE_MAX_LEVEL];
  76         unsigned long long raw;
  77 };
  78
  79 static const char * const cache_type_string[] = {
  80         "Data",
  81         "Instruction",
  82         "Unified",
  83 };
  84
  85 static struct cache_dir *cache_dir_cpu[NR_CPUS];
  86 static LIST_HEAD(cache_list);
  87
  88 void show_cacheinfo(struct seq_file *m)
  89 {
  90         struct cache *cache;
  91         int index = 0;
  92
  93         list_for_each_entry(cache, &cache_list, list) {
  94                 seq_printf(m, "cache%-11d: ", index);
  95                 seq_printf(m, "level=%d ", cache->level);
  96                 seq_printf(m, "type=%s ", cache_type_string[cache->type]);
  97                 seq_printf(m, "scope=%s ", cache->private ? "Private" : "Shared");
  98                 seq_printf(m, "size=%luK ", cache->size >> 10);
  99                 seq_printf(m, "line_size=%u ", cache->line_size);
 100                 seq_printf(m, "associativity=%d", cache->associativity);
 101                 seq_puts(m, "\n");
 102                 index++;
 103         }
 104 }
 105
 106 static inline unsigned long ecag(int ai, int li, int ti)
 107 {
 108         unsigned long cmd, val;
 109
 110         cmd = ai << 4 | li << 1 | ti;
 111         asm volatile(".insn     rsy,0xeb000000004c,%0,0,0(%1)" /* ecag */
 112                      : "=d" (val) : "a" (cmd));
 113         return val;
 114 }
 115
 116 static int __init cache_add(int level, int private, int type)
 117 {
 118         struct cache *cache;
 119         int ti;
 120
 121         cache = kzalloc(sizeof(*cache), GFP_KERNEL);
 122         if (!cache)
 123                 return -ENOMEM;
 124         if (type == CACHE_TYPE_INSTRUCTION)
 125                 ti = CACHE_TI_INSTRUCTION;
 126         else
 127                 ti = CACHE_TI_UNIFIED;
 128         cache->size = ecag(EXTRACT_SIZE, level, ti);
 129         cache->line_size = ecag(EXTRACT_LINE_SIZE, level, ti);
 130         cache->associativity = ecag(EXTRACT_ASSOCIATIVITY, level, ti);
 131         cache->nr_sets = cache->size / cache->associativity;
 132         cache->nr_sets /= cache->line_size;
 133         cache->private = private;
 134         cache->level = level + 1;
 135         cache->type = type - 1;
 136         list_add_tail(&cache->list, &cache_list);
 137         return 0;
 138 }
 139
 140 static void __init cache_build_info(void)
 141 {
 142         struct cache *cache, *next;
 143         union cache_topology ct;
 144         int level, private, rc;
 145
 146         ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0);
 147         for (level = 0; level < CACHE_MAX_LEVEL; level++) {
 148                 switch (ct.ci[level].scope) {
 149                 case CACHE_SCOPE_SHARED:
 150                         private = 0;
 151                         break;
 152                 case CACHE_SCOPE_PRIVATE:
 153                         private = 1;
 154                         break;
 155                 default:
 156                         return;
 157                 }
 158                 if (ct.ci[level].type == CACHE_TYPE_SEPARATE) {
 159                         rc  = cache_add(level, private, CACHE_TYPE_DATA);
 160                         rc |= cache_add(level, private, CACHE_TYPE_INSTRUCTION);
 161                 } else {
 162                         rc = cache_add(level, private, ct.ci[level].type);
 163                 }
 164                 if (rc)
 165                         goto error;
 166         }
 167         return;
 168 error:
 169         list_for_each_entry_safe(cache, next, &cache_list, list) {
 170                 list_del(&cache->list);
 171                 kfree(cache);
 172         }
 173 }
 174
 175 static struct cache_dir *cache_create_cache_dir(int cpu)
 176 {
 177         struct cache_dir *cache_dir;
 178         struct kobject *kobj = NULL;
 179         struct device *dev;
 180
 181         dev = get_cpu_device(cpu);
 182         if (!dev)
 183                 goto out;
 184         kobj = kobject_create_and_add("cache", &dev->kobj);
 185         if (!kobj)
 186                 goto out;
 187         cache_dir = kzalloc(sizeof(*cache_dir), GFP_KERNEL);
 188         if (!cache_dir)
 189                 goto out;
 190         cache_dir->kobj = kobj;
 191         cache_dir_cpu[cpu] = cache_dir;
 192         return cache_dir;
 193 out:
 194         kobject_put(kobj);
 195         return NULL;
 196 }
 197
 198 static struct cache_index_dir *kobj_to_cache_index_dir(struct kobject *kobj)
 199 {
 200         return container_of(kobj, struct cache_index_dir, kobj);
 201 }
 202
 203 static void cache_index_release(struct kobject *kobj)
 204 {
 205         struct cache_index_dir *index;
 206
 207         index = kobj_to_cache_index_dir(kobj);
 208         kfree(index);
 209 }
 210
 211 static ssize_t cache_index_show(struct kobject *kobj,
 212                                 struct attribute *attr, char *buf)
 213 {
 214         struct kobj_attribute *kobj_attr;
 215
 216         kobj_attr = container_of(attr, struct kobj_attribute, attr);
 217         return kobj_attr->show(kobj, kobj_attr, buf);
 218 }
 219
 220 #define DEFINE_CACHE_ATTR(_name, _format, _value)                       \
 221 static ssize_t cache_##_name##_show(struct kobject *kobj,               \
 222                                     struct kobj_attribute *attr,        \
 223                                     char *buf)                          \
 224 {                                                                       \
 225         struct cache_index_dir *index;                                  \
 226                                                                         \
 227         index = kobj_to_cache_index_dir(kobj);                          \
 228         return sprintf(buf, _format, _value);                           \
 229 }                                                                       \
 230 static struct kobj_attribute cache_##_name##_attr =                     \
 231         __ATTR(_name, 0444, cache_##_name##_show, NULL);
 232
 233 DEFINE_CACHE_ATTR(size, "%luK\n", index->cache->size >> 10);
 234 DEFINE_CACHE_ATTR(coherency_line_size, "%u\n", index->cache->line_size);
 235 DEFINE_CACHE_ATTR(number_of_sets, "%u\n", index->cache->nr_sets);
 236 DEFINE_CACHE_ATTR(ways_of_associativity, "%u\n", index->cache->associativity);
 237 DEFINE_CACHE_ATTR(type, "%s\n", cache_type_string[index->cache->type]);
 238 DEFINE_CACHE_ATTR(level, "%d\n", index->cache->level);
 239
 240 static ssize_t shared_cpu_map_func(struct kobject *kobj, int type, char *buf)
 241 {
 242         struct cache_index_dir *index;
 243         int len;
 244
 245         index = kobj_to_cache_index_dir(kobj);
 246         len = type ?
 247                 cpulist_scnprintf(buf, PAGE_SIZE - 2, cpumask_of(index->cpu)) :
 248                 cpumask_scnprintf(buf, PAGE_SIZE - 2, cpumask_of(index->cpu));
 249         len += sprintf(&buf[len], "\n");
 250         return len;
 251 }
 252
 253 static ssize_t shared_cpu_map_show(struct kobject *kobj,
 254                                    struct kobj_attribute *attr, char *buf)
 255 {
 256         return shared_cpu_map_func(kobj, 0, buf);
 257 }
 258 static struct kobj_attribute cache_shared_cpu_map_attr =
 259         __ATTR(shared_cpu_map, 0444, shared_cpu_map_show, NULL);
 260
 261 static ssize_t shared_cpu_list_show(struct kobject *kobj,
 262                                     struct kobj_attribute *attr, char *buf)
 263 {
 264         return shared_cpu_map_func(kobj, 1, buf);
 265 }
 266 static struct kobj_attribute cache_shared_cpu_list_attr =
 267         __ATTR(shared_cpu_list, 0444, shared_cpu_list_show, NULL);
 268
 269 static struct attribute *cache_index_default_attrs[] = {
 270         &cache_type_attr.attr,
 271         &cache_size_attr.attr,
 272         &cache_number_of_sets_attr.attr,
 273         &cache_ways_of_associativity_attr.attr,
 274         &cache_level_attr.attr,
 275         &cache_coherency_line_size_attr.attr,
 276         &cache_shared_cpu_map_attr.attr,
 277         &cache_shared_cpu_list_attr.attr,
 278         NULL,
 279 };
 280
 281 static const struct sysfs_ops cache_index_ops = {
 282         .show = cache_index_show,
 283 };
 284
 285 static struct kobj_type cache_index_type = {
 286         .sysfs_ops = &cache_index_ops,
 287         .release = cache_index_release,
 288         .default_attrs = cache_index_default_attrs,
 289 };
 290
 291 static int cache_create_index_dir(struct cache_dir *cache_dir,
 292                                   struct cache *cache, int index, int cpu)
 293 {
 294         struct cache_index_dir *index_dir;
 295         int rc;
 296
 297         index_dir = kzalloc(sizeof(*index_dir), GFP_KERNEL);
 298         if (!index_dir)
 299                 return -ENOMEM;
 300         index_dir->cache = cache;
 301         index_dir->cpu = cpu;
 302         rc = kobject_init_and_add(&index_dir->kobj, &cache_index_type,
 303                                   cache_dir->kobj, "index%d", index);
 304         if (rc)
 305                 goto out;
 306         index_dir->next = cache_dir->index;
 307         cache_dir->index = index_dir;
 308         return 0;
 309 out:
 310         kfree(index_dir);
 311         return rc;
 312 }
 313
 314 static int cache_add_cpu(int cpu)
 315 {
 316         struct cache_dir *cache_dir;
 317         struct cache *cache;
 318         int rc, index = 0;
 319
 320         if (list_empty(&cache_list))
 321                 return 0;
 322         cache_dir = cache_create_cache_dir(cpu);
 323         if (!cache_dir)
 324                 return -ENOMEM;
 325         list_for_each_entry(cache, &cache_list, list) {
 326                 if (!cache->private)
 327                         break;
 328                 rc = cache_create_index_dir(cache_dir, cache, index, cpu);
 329                 if (rc)
 330                         return rc;
 331                 index++;
 332         }
 333         return 0;
 334 }
 335
 336 static void cache_remove_cpu(int cpu)
 337 {
 338         struct cache_index_dir *index, *next;
 339         struct cache_dir *cache_dir;
 340
 341         cache_dir = cache_dir_cpu[cpu];
 342         if (!cache_dir)
 343                 return;
 344         index = cache_dir->index;
 345         while (index) {
 346                 next = index->next;
 347                 kobject_put(&index->kobj);
 348                 index = next;
 349         }
 350         kobject_put(cache_dir->kobj);
 351         kfree(cache_dir);
 352         cache_dir_cpu[cpu] = NULL;
 353 }
 354
 355 static int cache_hotplug(struct notifier_block *nfb, unsigned long action,
 356                          void *hcpu)
 357 {
 358         int cpu = (long)hcpu;
 359         int rc = 0;
 360
 361         switch (action & ~CPU_TASKS_FROZEN) {
 362         case CPU_ONLINE:
 363                 rc = cache_add_cpu(cpu);
 364                 if (rc)
 365                         cache_remove_cpu(cpu);
 366                 break;
 367         case CPU_DEAD:
 368                 cache_remove_cpu(cpu);
 369                 break;
 370         }
 371         return rc ? NOTIFY_BAD : NOTIFY_OK;
 372 }
 373
 374 static int __init cache_init(void)
 375 {
 376         int cpu;
 377
 378         if (!test_facility(34))
 379                 return 0;
 380         cache_build_info();
 381
 382         cpu_notifier_register_begin();
 383         for_each_online_cpu(cpu)
 384                 cache_add_cpu(cpu);
 385         __hotcpu_notifier(cache_hotplug, 0);
 386         cpu_notifier_register_done();
 387         return 0;
 388 }
 389 device_initcall(cache_init);