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   1 /*
   2  *  (c) 2005 Advanced Micro Devices, Inc.
   3  *  Your use of this code is subject to the terms and conditions of the
   4  *  GNU general public license version 2. See "COPYING" or
   5  *  http://www.gnu.org/licenses/gpl.html
   6  *
   7  *  Written by Jacob Shin - AMD, Inc.
   8  *
   9  *  Support : jacob.shin@amd.com
  10  *
  11  *  MC4_MISC0 DRAM ECC Error Threshold available under AMD K8 Rev F.
  12  *  MC4_MISC0 exists per physical processor.
  13  *
  14  */
  15
  16 #include <linux/cpu.h>
  17 #include <linux/errno.h>
  18 #include <linux/init.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/kobject.h>
  21 #include <linux/notifier.h>
  22 #include <linux/sched.h>
  23 #include <linux/smp.h>
  24 #include <linux/sysdev.h>
  25 #include <linux/sysfs.h>
  26 #include <asm/apic.h>
  27 #include <asm/mce.h>
  28 #include <asm/msr.h>
  29 #include <asm/percpu.h>
  30 #include <asm/idle.h>
  31
  32 #define PFX "mce_threshold: "
  33 #define VERSION "version 1.00.9"
  34 #define NR_BANKS 5
  35 #define THRESHOLD_MAX 0xFFF
  36 #define INT_TYPE_APIC 0x00020000
  37 #define MASK_VALID_HI 0x80000000
  38 #define MASK_LVTOFF_HI 0x00F00000
  39 #define MASK_COUNT_EN_HI 0x00080000
  40 #define MASK_INT_TYPE_HI 0x00060000
  41 #define MASK_OVERFLOW_HI 0x00010000
  42 #define MASK_ERR_COUNT_HI 0x00000FFF
  43 #define MASK_OVERFLOW 0x0001000000000000L
  44
  45 struct threshold_bank {
  46         unsigned int cpu;
  47         u8 bank;
  48         u8 interrupt_enable;
  49         u16 threshold_limit;
  50         struct kobject kobj;
  51 };
  52
  53 static struct threshold_bank threshold_defaults = {
  54         .interrupt_enable = 0,
  55         .threshold_limit = THRESHOLD_MAX,
  56 };
  57
  58 #ifdef CONFIG_SMP
  59 static unsigned char shared_bank[NR_BANKS] = {
  60         0, 0, 0, 0, 1
  61 };
  62 #endif
  63
  64 static DEFINE_PER_CPU(unsigned char, bank_map); /* see which banks are on */
  65
  66 /*
  67  * CPU Initialization
  68  */
  69
  70 /* must be called with correct cpu affinity */
  71 static void threshold_restart_bank(struct threshold_bank *b,
  72                                    int reset, u16 old_limit)
  73 {
  74         u32 mci_misc_hi, mci_misc_lo;
  75
  76         rdmsr(MSR_IA32_MC0_MISC + b->bank * 4, mci_misc_lo, mci_misc_hi);
  77
  78         if (b->threshold_limit < (mci_misc_hi & THRESHOLD_MAX))
  79                 reset = 1;      /* limit cannot be lower than err count */
  80
  81         if (reset) {            /* reset err count and overflow bit */
  82                 mci_misc_hi =
  83                     (mci_misc_hi & ~(MASK_ERR_COUNT_HI | MASK_OVERFLOW_HI)) |
  84                     (THRESHOLD_MAX - b->threshold_limit);
  85         } else if (old_limit) { /* change limit w/o reset */
  86                 int new_count = (mci_misc_hi & THRESHOLD_MAX) +
  87                     (old_limit - b->threshold_limit);
  88                 mci_misc_hi = (mci_misc_hi & ~MASK_ERR_COUNT_HI) |
  89                     (new_count & THRESHOLD_MAX);
  90         }
  91
  92         b->interrupt_enable ?
  93             (mci_misc_hi = (mci_misc_hi & ~MASK_INT_TYPE_HI) | INT_TYPE_APIC) :
  94             (mci_misc_hi &= ~MASK_INT_TYPE_HI);
  95
  96         mci_misc_hi |= MASK_COUNT_EN_HI;
  97         wrmsr(MSR_IA32_MC0_MISC + b->bank * 4, mci_misc_lo, mci_misc_hi);
  98 }
  99
 100 void __cpuinit mce_amd_feature_init(struct cpuinfo_x86 *c)
 101 {
 102         int bank;
 103         u32 mci_misc_lo, mci_misc_hi;
 104         unsigned int cpu = smp_processor_id();
 105
 106         for (bank = 0; bank < NR_BANKS; ++bank) {
 107                 rdmsr(MSR_IA32_MC0_MISC + bank * 4, mci_misc_lo, mci_misc_hi);
 108
 109                 /* !valid, !counter present, bios locked */
 110                 if (!(mci_misc_hi & MASK_VALID_HI) ||
 111                     !(mci_misc_hi & MASK_VALID_HI >> 1) ||
 112                     (mci_misc_hi & MASK_VALID_HI >> 2))
 113                         continue;
 114
 115                 per_cpu(bank_map, cpu) |= (1 << bank);
 116
 117 #ifdef CONFIG_SMP
 118                 if (shared_bank[bank] && cpu_core_id[cpu])
 119                         continue;
 120 #endif
 121
 122                 setup_threshold_lvt((mci_misc_hi & MASK_LVTOFF_HI) >> 20);
 123                 threshold_defaults.cpu = cpu;
 124                 threshold_defaults.bank = bank;
 125                 threshold_restart_bank(&threshold_defaults, 0, 0);
 126         }
 127 }
 128
 129 /*
 130  * APIC Interrupt Handler
 131  */
 132
 133 /*
 134  * threshold interrupt handler will service THRESHOLD_APIC_VECTOR.
 135  * the interrupt goes off when error_count reaches threshold_limit.
 136  * the handler will simply log mcelog w/ software defined bank number.
 137  */
 138 asmlinkage void mce_threshold_interrupt(void)
 139 {
 140         int bank;
 141         struct mce m;
 142
 143         ack_APIC_irq();
 144         exit_idle();
 145         irq_enter();
 146
 147         memset(&m, 0, sizeof(m));
 148         rdtscll(m.tsc);
 149         m.cpu = smp_processor_id();
 150
 151         /* assume first bank caused it */
 152         for (bank = 0; bank < NR_BANKS; ++bank) {
 153                 m.bank = MCE_THRESHOLD_BASE + bank;
 154                 rdmsrl(MSR_IA32_MC0_MISC + bank * 4, m.misc);
 155
 156                 if (m.misc & MASK_OVERFLOW) {
 157                         mce_log(&m);
 158                         goto out;
 159                 }
 160         }
 161       out:
 162         irq_exit();
 163 }
 164
 165 /*
 166  * Sysfs Interface
 167  */
 168
 169 static struct sysdev_class threshold_sysclass = {
 170         set_kset_name("threshold"),
 171 };
 172
 173 static DEFINE_PER_CPU(struct sys_device, device_threshold);
 174
 175 struct threshold_attr {
 176         struct attribute attr;
 177         ssize_t(*show) (struct threshold_bank *, char *);
 178         ssize_t(*store) (struct threshold_bank *, const char *, size_t count);
 179 };
 180
 181 static DEFINE_PER_CPU(struct threshold_bank *, threshold_banks[NR_BANKS]);
 182
 183 static cpumask_t affinity_set(unsigned int cpu)
 184 {
 185         cpumask_t oldmask = current->cpus_allowed;
 186         cpumask_t newmask = CPU_MASK_NONE;
 187         cpu_set(cpu, newmask);
 188         set_cpus_allowed(current, newmask);
 189         return oldmask;
 190 }
 191
 192 static void affinity_restore(cpumask_t oldmask)
 193 {
 194         set_cpus_allowed(current, oldmask);
 195 }
 196
 197 #define SHOW_FIELDS(name) \
 198         static ssize_t show_ ## name(struct threshold_bank * b, char *buf) \
 199         { \
 200                 return sprintf(buf, "%lx\n", (unsigned long) b->name); \
 201         }
 202 SHOW_FIELDS(interrupt_enable)
 203 SHOW_FIELDS(threshold_limit)
 204
 205 static ssize_t store_interrupt_enable(struct threshold_bank *b,
 206                                       const char *buf, size_t count)
 207 {
 208         char *end;
 209         cpumask_t oldmask;
 210         unsigned long new = simple_strtoul(buf, &end, 0);
 211         if (end == buf)
 212                 return -EINVAL;
 213         b->interrupt_enable = !!new;
 214
 215         oldmask = affinity_set(b->cpu);
 216         threshold_restart_bank(b, 0, 0);
 217         affinity_restore(oldmask);
 218
 219         return end - buf;
 220 }
 221
 222 static ssize_t store_threshold_limit(struct threshold_bank *b,
 223                                      const char *buf, size_t count)
 224 {
 225         char *end;
 226         cpumask_t oldmask;
 227         u16 old;
 228         unsigned long new = simple_strtoul(buf, &end, 0);
 229         if (end == buf)
 230                 return -EINVAL;
 231         if (new > THRESHOLD_MAX)
 232                 new = THRESHOLD_MAX;
 233         if (new < 1)
 234                 new = 1;
 235         old = b->threshold_limit;
 236         b->threshold_limit = new;
 237
 238         oldmask = affinity_set(b->cpu);
 239         threshold_restart_bank(b, 0, old);
 240         affinity_restore(oldmask);
 241
 242         return end - buf;
 243 }
 244
 245 static ssize_t show_error_count(struct threshold_bank *b, char *buf)
 246 {
 247         u32 high, low;
 248         cpumask_t oldmask;
 249         oldmask = affinity_set(b->cpu);
 250         rdmsr(MSR_IA32_MC0_MISC + b->bank * 4, low, high); /* ignore low 32 */
 251         affinity_restore(oldmask);
 252         return sprintf(buf, "%x\n",
 253                        (high & 0xFFF) - (THRESHOLD_MAX - b->threshold_limit));
 254 }
 255
 256 static ssize_t store_error_count(struct threshold_bank *b,
 257                                  const char *buf, size_t count)
 258 {
 259         cpumask_t oldmask;
 260         oldmask = affinity_set(b->cpu);
 261         threshold_restart_bank(b, 1, 0);
 262         affinity_restore(oldmask);
 263         return 1;
 264 }
 265
 266 #define THRESHOLD_ATTR(_name,_mode,_show,_store) {            \
 267         .attr = {.name = __stringify(_name), .mode = _mode }, \
 268         .show = _show,                                        \
 269         .store = _store,                                      \
 270 };
 271
 272 #define ATTR_FIELDS(name) \
 273         static struct threshold_attr name = \
 274         THRESHOLD_ATTR(name, 0644, show_## name, store_## name)
 275
 276 ATTR_FIELDS(interrupt_enable);
 277 ATTR_FIELDS(threshold_limit);
 278 ATTR_FIELDS(error_count);
 279
 280 static struct attribute *default_attrs[] = {
 281         &interrupt_enable.attr,
 282         &threshold_limit.attr,
 283         &error_count.attr,
 284         NULL
 285 };
 286
 287 #define to_bank(k) container_of(k,struct threshold_bank,kobj)
 288 #define to_attr(a) container_of(a,struct threshold_attr,attr)
 289
 290 static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
 291 {
 292         struct threshold_bank *b = to_bank(kobj);
 293         struct threshold_attr *a = to_attr(attr);
 294         ssize_t ret;
 295         ret = a->show ? a->show(b, buf) : -EIO;
 296         return ret;
 297 }
 298
 299 static ssize_t store(struct kobject *kobj, struct attribute *attr,
 300                      const char *buf, size_t count)
 301 {
 302         struct threshold_bank *b = to_bank(kobj);
 303         struct threshold_attr *a = to_attr(attr);
 304         ssize_t ret;
 305         ret = a->store ? a->store(b, buf, count) : -EIO;
 306         return ret;
 307 }
 308
 309 static struct sysfs_ops threshold_ops = {
 310         .show = show,
 311         .store = store,
 312 };
 313
 314 static struct kobj_type threshold_ktype = {
 315         .sysfs_ops = &threshold_ops,
 316         .default_attrs = default_attrs,
 317 };
 318
 319 /* symlinks sibling shared banks to first core.  first core owns dir/files. */
 320 static __cpuinit int threshold_create_bank(unsigned int cpu, int bank)
 321 {
 322         int err = 0;
 323         struct threshold_bank *b = NULL;
 324
 325 #ifdef CONFIG_SMP
 326         if (cpu_core_id[cpu] && shared_bank[bank]) {    /* symlink */
 327                 char name[16];
 328                 unsigned lcpu = first_cpu(cpu_core_map[cpu]);
 329                 if (cpu_core_id[lcpu])
 330                         goto out;       /* first core not up yet */
 331
 332                 b = per_cpu(threshold_banks, lcpu)[bank];
 333                 if (!b)
 334                         goto out;
 335                 sprintf(name, "bank%i", bank);
 336                 err = sysfs_create_link(&per_cpu(device_threshold, cpu).kobj,
 337                                         &b->kobj, name);
 338                 if (err)
 339                         goto out;
 340                 per_cpu(threshold_banks, cpu)[bank] = b;
 341                 goto out;
 342         }
 343 #endif
 344
 345         b = kmalloc(sizeof(struct threshold_bank), GFP_KERNEL);
 346         if (!b) {
 347                 err = -ENOMEM;
 348                 goto out;
 349         }
 350         memset(b, 0, sizeof(struct threshold_bank));
 351
 352         b->cpu = cpu;
 353         b->bank = bank;
 354         b->interrupt_enable = 0;
 355         b->threshold_limit = THRESHOLD_MAX;
 356         kobject_set_name(&b->kobj, "bank%i", bank);
 357         b->kobj.parent = &per_cpu(device_threshold, cpu).kobj;
 358         b->kobj.ktype = &threshold_ktype;
 359
 360         err = kobject_register(&b->kobj);
 361         if (err) {
 362                 kfree(b);
 363                 goto out;
 364         }
 365         per_cpu(threshold_banks, cpu)[bank] = b;
 366       out:
 367         return err;
 368 }
 369
 370 /* create dir/files for all valid threshold banks */
 371 static __cpuinit int threshold_create_device(unsigned int cpu)
 372 {
 373         int bank;
 374         int err = 0;
 375
 376         per_cpu(device_threshold, cpu).id = cpu;
 377         per_cpu(device_threshold, cpu).cls = &threshold_sysclass;
 378         err = sysdev_register(&per_cpu(device_threshold, cpu));
 379         if (err)
 380                 goto out;
 381
 382         for (bank = 0; bank < NR_BANKS; ++bank) {
 383                 if (!(per_cpu(bank_map, cpu) & 1 << bank))
 384                         continue;
 385                 err = threshold_create_bank(cpu, bank);
 386                 if (err)
 387                         goto out;
 388         }
 389       out:
 390         return err;
 391 }
 392
 393 #ifdef CONFIG_HOTPLUG_CPU
 394 /*
 395  * let's be hotplug friendly.
 396  * in case of multiple core processors, the first core always takes ownership
 397  *   of shared sysfs dir/files, and rest of the cores will be symlinked to it.
 398  */
 399
 400 /* cpu hotplug call removes all symlinks before first core dies */
 401 static __cpuinit void threshold_remove_bank(unsigned int cpu, int bank)
 402 {
 403         struct threshold_bank *b;
 404         char name[16];
 405
 406         b = per_cpu(threshold_banks, cpu)[bank];
 407         if (!b)
 408                 return;
 409         if (shared_bank[bank] && atomic_read(&b->kobj.kref.refcount) > 2) {
 410                 sprintf(name, "bank%i", bank);
 411                 sysfs_remove_link(&per_cpu(device_threshold, cpu).kobj, name);
 412                 per_cpu(threshold_banks, cpu)[bank] = NULL;
 413         } else {
 414                 kobject_unregister(&b->kobj);
 415                 kfree(per_cpu(threshold_banks, cpu)[bank]);
 416         }
 417 }
 418
 419 static __cpuinit void threshold_remove_device(unsigned int cpu)
 420 {
 421         int bank;
 422
 423         for (bank = 0; bank < NR_BANKS; ++bank) {
 424                 if (!(per_cpu(bank_map, cpu) & 1 << bank))
 425                         continue;
 426                 threshold_remove_bank(cpu, bank);
 427         }
 428         sysdev_unregister(&per_cpu(device_threshold, cpu));
 429 }
 430
 431 /* link all existing siblings when first core comes up */
 432 static __cpuinit int threshold_create_symlinks(unsigned int cpu)
 433 {
 434         int bank, err = 0;
 435         unsigned int lcpu = 0;
 436
 437         if (cpu_core_id[cpu])
 438                 return 0;
 439         for_each_cpu_mask(lcpu, cpu_core_map[cpu]) {
 440                 if (lcpu == cpu)
 441                         continue;
 442                 for (bank = 0; bank < NR_BANKS; ++bank) {
 443                         if (!(per_cpu(bank_map, cpu) & 1 << bank))
 444                                 continue;
 445                         if (!shared_bank[bank])
 446                                 continue;
 447                         err = threshold_create_bank(lcpu, bank);
 448                 }
 449         }
 450         return err;
 451 }
 452
 453 /* remove all symlinks before first core dies. */
 454 static __cpuinit void threshold_remove_symlinks(unsigned int cpu)
 455 {
 456         int bank;
 457         unsigned int lcpu = 0;
 458         if (cpu_core_id[cpu])
 459                 return;
 460         for_each_cpu_mask(lcpu, cpu_core_map[cpu]) {
 461                 if (lcpu == cpu)
 462                         continue;
 463                 for (bank = 0; bank < NR_BANKS; ++bank) {
 464                         if (!(per_cpu(bank_map, cpu) & 1 << bank))
 465                                 continue;
 466                         if (!shared_bank[bank])
 467                                 continue;
 468                         threshold_remove_bank(lcpu, bank);
 469                 }
 470         }
 471 }
 472 #else /* !CONFIG_HOTPLUG_CPU */
 473 static __cpuinit void threshold_create_symlinks(unsigned int cpu)
 474 {
 475 }
 476 static __cpuinit void threshold_remove_symlinks(unsigned int cpu)
 477 {
 478 }
 479 static void threshold_remove_device(unsigned int cpu)
 480 {
 481 }
 482 #endif
 483
 484 /* get notified when a cpu comes on/off */
 485 static int threshold_cpu_callback(struct notifier_block *nfb,
 486                                             unsigned long action, void *hcpu)
 487 {
 488         /* cpu was unsigned int to begin with */
 489         unsigned int cpu = (unsigned long)hcpu;
 490
 491         if (cpu >= NR_CPUS)
 492                 goto out;
 493
 494         switch (action) {
 495         case CPU_ONLINE:
 496                 threshold_create_device(cpu);
 497                 threshold_create_symlinks(cpu);
 498                 break;
 499         case CPU_DOWN_PREPARE:
 500                 threshold_remove_symlinks(cpu);
 501                 break;
 502         case CPU_DOWN_FAILED:
 503                 threshold_create_symlinks(cpu);
 504                 break;
 505         case CPU_DEAD:
 506                 threshold_remove_device(cpu);
 507                 break;
 508         default:
 509                 break;
 510         }
 511       out:
 512         return NOTIFY_OK;
 513 }
 514
 515 static struct notifier_block threshold_cpu_notifier = {
 516         .notifier_call = threshold_cpu_callback,
 517 };
 518
 519 static __init int threshold_init_device(void)
 520 {
 521         int err;
 522         int lcpu = 0;
 523
 524         err = sysdev_class_register(&threshold_sysclass);
 525         if (err)
 526                 goto out;
 527
 528         /* to hit CPUs online before the notifier is up */
 529         for_each_online_cpu(lcpu) {
 530                 err = threshold_create_device(lcpu);
 531                 if (err)
 532                         goto out;
 533         }
 534         register_cpu_notifier(&threshold_cpu_notifier);
 535
 536       out:
 537         return err;
 538 }
 539
 540 device_initcall(threshold_init_device);