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_NOTEXISTS:
 150                 case CACHE_SCOPE_RESERVED:
 151                         return;
 152                 case CACHE_SCOPE_SHARED:
 153                         private = 0;
 154                         break;
 155                 case CACHE_SCOPE_PRIVATE:
 156                         private = 1;
 157                         break;
 158                 }
 159                 if (ct.ci[level].type == CACHE_TYPE_SEPARATE) {
 160                         rc  = cache_add(level, private, CACHE_TYPE_DATA);
 161                         rc |= cache_add(level, private, CACHE_TYPE_INSTRUCTION);
 162                 } else {
 163                         rc = cache_add(level, private, ct.ci[level].type);
 164                 }
 165                 if (rc)
 166                         goto error;
 167         }
 168         return;
 169 error:
 170         list_for_each_entry_safe(cache, next, &cache_list, list) {
 171                 list_del(&cache->list);
 172                 kfree(cache);
 173         }
 174 }
 175
 176 static struct cache_dir *cache_create_cache_dir(int cpu)
 177 {
 178         struct cache_dir *cache_dir;
 179         struct kobject *kobj = NULL;
 180         struct device *dev;
 181
 182         dev = get_cpu_device(cpu);
 183         if (!dev)
 184                 goto out;
 185         kobj = kobject_create_and_add("cache", &dev->kobj);
 186         if (!kobj)
 187                 goto out;
 188         cache_dir = kzalloc(sizeof(*cache_dir), GFP_KERNEL);
 189         if (!cache_dir)
 190                 goto out;
 191         cache_dir->kobj = kobj;
 192         cache_dir_cpu[cpu] = cache_dir;
 193         return cache_dir;
 194 out:
 195         kobject_put(kobj);
 196         return NULL;
 197 }
 198
 199 static struct cache_index_dir *kobj_to_cache_index_dir(struct kobject *kobj)
 200 {
 201         return container_of(kobj, struct cache_index_dir, kobj);
 202 }
 203
 204 static void cache_index_release(struct kobject *kobj)
 205 {
 206         struct cache_index_dir *index;
 207
 208         index = kobj_to_cache_index_dir(kobj);
 209         kfree(index);
 210 }
 211
 212 static ssize_t cache_index_show(struct kobject *kobj,
 213                                 struct attribute *attr, char *buf)
 214 {
 215         struct kobj_attribute *kobj_attr;
 216
 217         kobj_attr = container_of(attr, struct kobj_attribute, attr);
 218         return kobj_attr->show(kobj, kobj_attr, buf);
 219 }
 220
 221 #define DEFINE_CACHE_ATTR(_name, _format, _value)                       \
 222 static ssize_t cache_##_name##_show(struct kobject *kobj,               \
 223                                     struct kobj_attribute *attr,        \
 224                                     char *buf)                          \
 225 {                                                                       \
 226         struct cache_index_dir *index;                                  \
 227                                                                         \
 228         index = kobj_to_cache_index_dir(kobj);                          \
 229         return sprintf(buf, _format, _value);                           \
 230 }                                                                       \
 231 static struct kobj_attribute cache_##_name##_attr =                     \
 232         __ATTR(_name, 0444, cache_##_name##_show, NULL);
 233
 234 DEFINE_CACHE_ATTR(size, "%luK\n", index->cache->size >> 10);
 235 DEFINE_CACHE_ATTR(coherency_line_size, "%u\n", index->cache->line_size);
 236 DEFINE_CACHE_ATTR(number_of_sets, "%u\n", index->cache->nr_sets);
 237 DEFINE_CACHE_ATTR(ways_of_associativity, "%u\n", index->cache->associativity);
 238 DEFINE_CACHE_ATTR(type, "%s\n", cache_type_string[index->cache->type]);
 239 DEFINE_CACHE_ATTR(level, "%d\n", index->cache->level);
 240
 241 static ssize_t shared_cpu_map_func(struct kobject *kobj, int type, char *buf)
 242 {
 243         struct cache_index_dir *index;
 244         int len;
 245
 246         index = kobj_to_cache_index_dir(kobj);
 247         len = type ?
 248                 cpulist_scnprintf(buf, PAGE_SIZE - 2, cpumask_of(index->cpu)) :
 249                 cpumask_scnprintf(buf, PAGE_SIZE - 2, cpumask_of(index->cpu));
 250         len += sprintf(&buf[len], "\n");
 251         return len;
 252 }
 253
 254 static ssize_t shared_cpu_map_show(struct kobject *kobj,
 255                                    struct kobj_attribute *attr, char *buf)
 256 {
 257         return shared_cpu_map_func(kobj, 0, buf);
 258 }
 259 static struct kobj_attribute cache_shared_cpu_map_attr =
 260         __ATTR(shared_cpu_map, 0444, shared_cpu_map_show, NULL);
 261
 262 static ssize_t shared_cpu_list_show(struct kobject *kobj,
 263                                     struct kobj_attribute *attr, char *buf)
 264 {
 265         return shared_cpu_map_func(kobj, 1, buf);
 266 }
 267 static struct kobj_attribute cache_shared_cpu_list_attr =
 268         __ATTR(shared_cpu_list, 0444, shared_cpu_list_show, NULL);
 269
 270 static struct attribute *cache_index_default_attrs[] = {
 271         &cache_type_attr.attr,
 272         &cache_size_attr.attr,
 273         &cache_number_of_sets_attr.attr,
 274         &cache_ways_of_associativity_attr.attr,
 275         &cache_level_attr.attr,
 276         &cache_coherency_line_size_attr.attr,
 277         &cache_shared_cpu_map_attr.attr,
 278         &cache_shared_cpu_list_attr.attr,
 279         NULL,
 280 };
 281
 282 static const struct sysfs_ops cache_index_ops = {
 283         .show = cache_index_show,
 284 };
 285
 286 static struct kobj_type cache_index_type = {
 287         .sysfs_ops = &cache_index_ops,
 288         .release = cache_index_release,
 289         .default_attrs = cache_index_default_attrs,
 290 };
 291
 292 static int cache_create_index_dir(struct cache_dir *cache_dir,
 293                                   struct cache *cache, int index, int cpu)
 294 {
 295         struct cache_index_dir *index_dir;
 296         int rc;
 297
 298         index_dir = kzalloc(sizeof(*index_dir), GFP_KERNEL);
 299         if (!index_dir)
 300                 return -ENOMEM;
 301         index_dir->cache = cache;
 302         index_dir->cpu = cpu;
 303         rc = kobject_init_and_add(&index_dir->kobj, &cache_index_type,
 304                                   cache_dir->kobj, "index%d", index);
 305         if (rc)
 306                 goto out;
 307         index_dir->next = cache_dir->index;
 308         cache_dir->index = index_dir;
 309         return 0;
 310 out:
 311         kfree(index_dir);
 312         return rc;
 313 }
 314
 315 static int cache_add_cpu(int cpu)
 316 {
 317         struct cache_dir *cache_dir;
 318         struct cache *cache;
 319         int rc, index = 0;
 320
 321         if (list_empty(&cache_list))
 322                 return 0;
 323         cache_dir = cache_create_cache_dir(cpu);
 324         if (!cache_dir)
 325                 return -ENOMEM;
 326         list_for_each_entry(cache, &cache_list, list) {
 327                 if (!cache->private)
 328                         break;
 329                 rc = cache_create_index_dir(cache_dir, cache, index, cpu);
 330                 if (rc)
 331                         return rc;
 332                 index++;
 333         }
 334         return 0;
 335 }
 336
 337 static void cache_remove_cpu(int cpu)
 338 {
 339         struct cache_index_dir *index, *next;
 340         struct cache_dir *cache_dir;
 341
 342         cache_dir = cache_dir_cpu[cpu];
 343         if (!cache_dir)
 344                 return;
 345         index = cache_dir->index;
 346         while (index) {
 347                 next = index->next;
 348                 kobject_put(&index->kobj);
 349                 index = next;
 350         }
 351         kobject_put(cache_dir->kobj);
 352         kfree(cache_dir);
 353         cache_dir_cpu[cpu] = NULL;
 354 }
 355
 356 static int cache_hotplug(struct notifier_block *nfb, unsigned long action,
 357                          void *hcpu)
 358 {
 359         int cpu = (long)hcpu;
 360         int rc = 0;
 361
 362         switch (action & ~CPU_TASKS_FROZEN) {
 363         case CPU_ONLINE:
 364                 rc = cache_add_cpu(cpu);
 365                 if (rc)
 366                         cache_remove_cpu(cpu);
 367                 break;
 368         case CPU_DEAD:
 369                 cache_remove_cpu(cpu);
 370                 break;
 371         }
 372         return rc ? NOTIFY_BAD : NOTIFY_OK;
 373 }
 374
 375 static int __init cache_init(void)
 376 {
 377         int cpu;
 378
 379         if (!test_facility(34))
 380                 return 0;
 381         cache_build_info();
 382         for_each_online_cpu(cpu)
 383                 cache_add_cpu(cpu);
 384         hotcpu_notifier(cache_hotplug, 0);
 385         return 0;
 386 }
 387 device_initcall(cache_init);