arch/x86/kernel/cpu/mcheck/therm_throt.c

   1 /*
   2  * Thermal throttle event support code (such as syslog messaging and rate
   3  * limiting) that was factored out from x86_64 (mce_intel.c) and i386 (p4.c).
   4  *
   5  * This allows consistent reporting of CPU thermal throttle events.
   6  *
   7  * Maintains a counter in /sys that keeps track of the number of thermal
   8  * events, such that the user knows how bad the thermal problem might be
   9  * (since the logging to syslog and mcelog is rate limited).
  10  *
  11  * Author: Dmitriy Zavin (dmitriyz@google.com)
  12  *
  13  * Credits: Adapted from Zwane Mwaikambo's original code in mce_intel.c.
  14  *          Inspired by Ross Biro's and Al Borchers' counter code.
  15  */
  16 #include <linux/interrupt.h>
  17 #include <linux/notifier.h>
  18 #include <linux/jiffies.h>
  19 #include <linux/kernel.h>
  20 #include <linux/percpu.h>
  21 #include <linux/export.h>
  22 #include <linux/types.h>
  23 #include <linux/init.h>
  24 #include <linux/smp.h>
  25 #include <linux/cpu.h>
  26
  27 #include <asm/processor.h>
  28 #include <asm/apic.h>
  29 #include <asm/idle.h>
  30 #include <asm/mce.h>
  31 #include <asm/msr.h>
  32 #include <asm/trace/irq_vectors.h>
  33
  34 /* How long to wait between reporting thermal events */
  35 #define CHECK_INTERVAL          (300 * HZ)
  36
  37 #define THERMAL_THROTTLING_EVENT        0
  38 #define POWER_LIMIT_EVENT               1
  39
  40 /*
  41  * Current thermal event state:
  42  */
  43 struct _thermal_state {
  44         bool                    new_event;
  45         int                     event;
  46         u64                     next_check;
  47         unsigned long           count;
  48         unsigned long           last_count;
  49 };
  50
  51 struct thermal_state {
  52         struct _thermal_state core_throttle;
  53         struct _thermal_state core_power_limit;
  54         struct _thermal_state package_throttle;
  55         struct _thermal_state package_power_limit;
  56         struct _thermal_state core_thresh0;
  57         struct _thermal_state core_thresh1;
  58         struct _thermal_state pkg_thresh0;
  59         struct _thermal_state pkg_thresh1;
  60 };
  61
  62 /* Callback to handle core threshold interrupts */
  63 int (*platform_thermal_notify)(__u64 msr_val);
  64 EXPORT_SYMBOL(platform_thermal_notify);
  65
  66 /* Callback to handle core package threshold_interrupts */
  67 int (*platform_thermal_package_notify)(__u64 msr_val);
  68 EXPORT_SYMBOL_GPL(platform_thermal_package_notify);
  69
  70 /* Callback support of rate control, return true, if
  71  * callback has rate control */
  72 bool (*platform_thermal_package_rate_control)(void);
  73 EXPORT_SYMBOL_GPL(platform_thermal_package_rate_control);
  74
  75
  76 static DEFINE_PER_CPU(struct thermal_state, thermal_state);
  77
  78 static atomic_t therm_throt_en  = ATOMIC_INIT(0);
  79
  80 static u32 lvtthmr_init __read_mostly;
  81
  82 #ifdef CONFIG_SYSFS
  83 #define define_therm_throt_device_one_ro(_name)                         \
  84         static DEVICE_ATTR(_name, 0444,                                 \
  85                            therm_throt_device_show_##_name,             \
  86                                    NULL)                                \
  87
  88 #define define_therm_throt_device_show_func(event, name)                \
  89                                                                         \
  90 static ssize_t therm_throt_device_show_##event##_##name(                \
  91                         struct device *dev,                             \
  92                         struct device_attribute *attr,                  \
  93                         char *buf)                                      \
  94 {                                                                       \
  95         unsigned int cpu = dev->id;                                     \
  96         ssize_t ret;                                                    \
  97                                                                         \
  98         preempt_disable();      /* CPU hotplug */                       \
  99         if (cpu_online(cpu)) {                                          \
 100                 ret = sprintf(buf, "%lu\n",                             \
 101                               per_cpu(thermal_state, cpu).event.name);  \
 102         } else                                                          \
 103                 ret = 0;                                                \
 104         preempt_enable();                                               \
 105                                                                         \
 106         return ret;                                                     \
 107 }
 108
 109 define_therm_throt_device_show_func(core_throttle, count);
 110 define_therm_throt_device_one_ro(core_throttle_count);
 111
 112 define_therm_throt_device_show_func(core_power_limit, count);
 113 define_therm_throt_device_one_ro(core_power_limit_count);
 114
 115 define_therm_throt_device_show_func(package_throttle, count);
 116 define_therm_throt_device_one_ro(package_throttle_count);
 117
 118 define_therm_throt_device_show_func(package_power_limit, count);
 119 define_therm_throt_device_one_ro(package_power_limit_count);
 120
 121 static struct attribute *thermal_throttle_attrs[] = {
 122         &dev_attr_core_throttle_count.attr,
 123         NULL
 124 };
 125
 126 static struct attribute_group thermal_attr_group = {
 127         .attrs  = thermal_throttle_attrs,
 128         .name   = "thermal_throttle"
 129 };
 130 #endif /* CONFIG_SYSFS */
 131
 132 #define CORE_LEVEL      0
 133 #define PACKAGE_LEVEL   1
 134
 135 /***
 136  * therm_throt_process - Process thermal throttling event from interrupt
 137  * @curr: Whether the condition is current or not (boolean), since the
 138  *        thermal interrupt normally gets called both when the thermal
 139  *        event begins and once the event has ended.
 140  *
 141  * This function is called by the thermal interrupt after the
 142  * IRQ has been acknowledged.
 143  *
 144  * It will take care of rate limiting and printing messages to the syslog.
 145  *
 146  * Returns: 0 : Event should NOT be further logged, i.e. still in
 147  *              "timeout" from previous log message.
 148  *          1 : Event should be logged further, and a message has been
 149  *              printed to the syslog.
 150  */
 151 static int therm_throt_process(bool new_event, int event, int level)
 152 {
 153         struct _thermal_state *state;
 154         unsigned int this_cpu = smp_processor_id();
 155         bool old_event;
 156         u64 now;
 157         struct thermal_state *pstate = &per_cpu(thermal_state, this_cpu);
 158
 159         now = get_jiffies_64();
 160         if (level == CORE_LEVEL) {
 161                 if (event == THERMAL_THROTTLING_EVENT)
 162                         state = &pstate->core_throttle;
 163                 else if (event == POWER_LIMIT_EVENT)
 164                         state = &pstate->core_power_limit;
 165                 else
 166                          return 0;
 167         } else if (level == PACKAGE_LEVEL) {
 168                 if (event == THERMAL_THROTTLING_EVENT)
 169                         state = &pstate->package_throttle;
 170                 else if (event == POWER_LIMIT_EVENT)
 171                         state = &pstate->package_power_limit;
 172                 else
 173                         return 0;
 174         } else
 175                 return 0;
 176
 177         old_event = state->new_event;
 178         state->new_event = new_event;
 179
 180         if (new_event)
 181                 state->count++;
 182
 183         if (time_before64(now, state->next_check) &&
 184                         state->count != state->last_count)
 185                 return 0;
 186
 187         state->next_check = now + CHECK_INTERVAL;
 188         state->last_count = state->count;
 189
 190         /* if we just entered the thermal event */
 191         if (new_event) {
 192                 if (event == THERMAL_THROTTLING_EVENT)
 193                         printk(KERN_CRIT "CPU%d: %s temperature above threshold, cpu clock throttled (total events = %lu)\n",
 194                                 this_cpu,
 195                                 level == CORE_LEVEL ? "Core" : "Package",
 196                                 state->count);
 197                 return 1;
 198         }
 199         if (old_event) {
 200                 if (event == THERMAL_THROTTLING_EVENT)
 201                         printk(KERN_INFO "CPU%d: %s temperature/speed normal\n",
 202                                 this_cpu,
 203                                 level == CORE_LEVEL ? "Core" : "Package");
 204                 return 1;
 205         }
 206
 207         return 0;
 208 }
 209
 210 static int thresh_event_valid(int level, int event)
 211 {
 212         struct _thermal_state *state;
 213         unsigned int this_cpu = smp_processor_id();
 214         struct thermal_state *pstate = &per_cpu(thermal_state, this_cpu);
 215         u64 now = get_jiffies_64();
 216
 217         if (level == PACKAGE_LEVEL)
 218                 state = (event == 0) ? &pstate->pkg_thresh0 :
 219                                                 &pstate->pkg_thresh1;
 220         else
 221                 state = (event == 0) ? &pstate->core_thresh0 :
 222                                                 &pstate->core_thresh1;
 223
 224         if (time_before64(now, state->next_check))
 225                 return 0;
 226
 227         state->next_check = now + CHECK_INTERVAL;
 228
 229         return 1;
 230 }
 231
 232 static bool int_pln_enable;
 233 static int __init int_pln_enable_setup(char *s)
 234 {
 235         int_pln_enable = true;
 236
 237         return 1;
 238 }
 239 __setup("int_pln_enable", int_pln_enable_setup);
 240
 241 #ifdef CONFIG_SYSFS
 242 /* Add/Remove thermal_throttle interface for CPU device: */
 243 static int thermal_throttle_add_dev(struct device *dev, unsigned int cpu)
 244 {
 245         int err;
 246         struct cpuinfo_x86 *c = &cpu_data(cpu);
 247
 248         err = sysfs_create_group(&dev->kobj, &thermal_attr_group);
 249         if (err)
 250                 return err;
 251
 252         if (cpu_has(c, X86_FEATURE_PLN) && int_pln_enable)
 253                 err = sysfs_add_file_to_group(&dev->kobj,
 254                                               &dev_attr_core_power_limit_count.attr,
 255                                               thermal_attr_group.name);
 256         if (cpu_has(c, X86_FEATURE_PTS)) {
 257                 err = sysfs_add_file_to_group(&dev->kobj,
 258                                               &dev_attr_package_throttle_count.attr,
 259                                               thermal_attr_group.name);
 260                 if (cpu_has(c, X86_FEATURE_PLN) && int_pln_enable)
 261                         err = sysfs_add_file_to_group(&dev->kobj,
 262                                         &dev_attr_package_power_limit_count.attr,
 263                                         thermal_attr_group.name);
 264         }
 265
 266         return err;
 267 }
 268
 269 static void thermal_throttle_remove_dev(struct device *dev)
 270 {
 271         sysfs_remove_group(&dev->kobj, &thermal_attr_group);
 272 }
 273
 274 /* Get notified when a cpu comes on/off. Be hotplug friendly. */
 275 static int
 276 thermal_throttle_cpu_callback(struct notifier_block *nfb,
 277                               unsigned long action,
 278                               void *hcpu)
 279 {
 280         unsigned int cpu = (unsigned long)hcpu;
 281         struct device *dev;
 282         int err = 0;
 283
 284         dev = get_cpu_device(cpu);
 285
 286         switch (action) {
 287         case CPU_UP_PREPARE:
 288         case CPU_UP_PREPARE_FROZEN:
 289                 err = thermal_throttle_add_dev(dev, cpu);
 290                 WARN_ON(err);
 291                 break;
 292         case CPU_UP_CANCELED:
 293         case CPU_UP_CANCELED_FROZEN:
 294         case CPU_DEAD:
 295         case CPU_DEAD_FROZEN:
 296                 thermal_throttle_remove_dev(dev);
 297                 break;
 298         }
 299         return notifier_from_errno(err);
 300 }
 301
 302 static struct notifier_block thermal_throttle_cpu_notifier =
 303 {
 304         .notifier_call = thermal_throttle_cpu_callback,
 305 };
 306
 307 static __init int thermal_throttle_init_device(void)
 308 {
 309         unsigned int cpu = 0;
 310         int err;
 311
 312         if (!atomic_read(&therm_throt_en))
 313                 return 0;
 314
 315         cpu_notifier_register_begin();
 316
 317         /* connect live CPUs to sysfs */
 318         for_each_online_cpu(cpu) {
 319                 err = thermal_throttle_add_dev(get_cpu_device(cpu), cpu);
 320                 WARN_ON(err);
 321         }
 322
 323         __register_hotcpu_notifier(&thermal_throttle_cpu_notifier);
 324         cpu_notifier_register_done();
 325
 326         return 0;
 327 }
 328 device_initcall(thermal_throttle_init_device);
 329
 330 #endif /* CONFIG_SYSFS */
 331
 332 static void notify_package_thresholds(__u64 msr_val)
 333 {
 334         bool notify_thres_0 = false;
 335         bool notify_thres_1 = false;
 336
 337         if (!platform_thermal_package_notify)
 338                 return;
 339
 340         /* lower threshold check */
 341         if (msr_val & THERM_LOG_THRESHOLD0)
 342                 notify_thres_0 = true;
 343         /* higher threshold check */
 344         if (msr_val & THERM_LOG_THRESHOLD1)
 345                 notify_thres_1 = true;
 346
 347         if (!notify_thres_0 && !notify_thres_1)
 348                 return;
 349
 350         if (platform_thermal_package_rate_control &&
 351                 platform_thermal_package_rate_control()) {
 352                 /* Rate control is implemented in callback */
 353                 platform_thermal_package_notify(msr_val);
 354                 return;
 355         }
 356
 357         /* lower threshold reached */
 358         if (notify_thres_0 && thresh_event_valid(PACKAGE_LEVEL, 0))
 359                 platform_thermal_package_notify(msr_val);
 360         /* higher threshold reached */
 361         if (notify_thres_1 && thresh_event_valid(PACKAGE_LEVEL, 1))
 362                 platform_thermal_package_notify(msr_val);
 363 }
 364
 365 static void notify_thresholds(__u64 msr_val)
 366 {
 367         /* check whether the interrupt handler is defined;
 368          * otherwise simply return
 369          */
 370         if (!platform_thermal_notify)
 371                 return;
 372
 373         /* lower threshold reached */
 374         if ((msr_val & THERM_LOG_THRESHOLD0) &&
 375                         thresh_event_valid(CORE_LEVEL, 0))
 376                 platform_thermal_notify(msr_val);
 377         /* higher threshold reached */
 378         if ((msr_val & THERM_LOG_THRESHOLD1) &&
 379                         thresh_event_valid(CORE_LEVEL, 1))
 380                 platform_thermal_notify(msr_val);
 381 }
 382
 383 /* Thermal transition interrupt handler */
 384 static void intel_thermal_interrupt(void)
 385 {
 386         __u64 msr_val;
 387
 388         rdmsrl(MSR_IA32_THERM_STATUS, msr_val);
 389
 390         /* Check for violation of core thermal thresholds*/
 391         notify_thresholds(msr_val);
 392
 393         if (therm_throt_process(msr_val & THERM_STATUS_PROCHOT,
 394                                 THERMAL_THROTTLING_EVENT,
 395                                 CORE_LEVEL) != 0)
 396                 mce_log_therm_throt_event(msr_val);
 397
 398         if (this_cpu_has(X86_FEATURE_PLN) && int_pln_enable)
 399                 therm_throt_process(msr_val & THERM_STATUS_POWER_LIMIT,
 400                                         POWER_LIMIT_EVENT,
 401                                         CORE_LEVEL);
 402
 403         if (this_cpu_has(X86_FEATURE_PTS)) {
 404                 rdmsrl(MSR_IA32_PACKAGE_THERM_STATUS, msr_val);
 405                 /* check violations of package thermal thresholds */
 406                 notify_package_thresholds(msr_val);
 407                 therm_throt_process(msr_val & PACKAGE_THERM_STATUS_PROCHOT,
 408                                         THERMAL_THROTTLING_EVENT,
 409                                         PACKAGE_LEVEL);
 410                 if (this_cpu_has(X86_FEATURE_PLN) && int_pln_enable)
 411                         therm_throt_process(msr_val &
 412                                         PACKAGE_THERM_STATUS_POWER_LIMIT,
 413                                         POWER_LIMIT_EVENT,
 414                                         PACKAGE_LEVEL);
 415         }
 416 }
 417
 418 static void unexpected_thermal_interrupt(void)
 419 {
 420         printk(KERN_ERR "CPU%d: Unexpected LVT thermal interrupt!\n",
 421                         smp_processor_id());
 422 }
 423
 424 static void (*smp_thermal_vector)(void) = unexpected_thermal_interrupt;
 425
 426 static inline void __smp_thermal_interrupt(void)
 427 {
 428         inc_irq_stat(irq_thermal_count);
 429         smp_thermal_vector();
 430 }
 431
 432 asmlinkage __visible void smp_thermal_interrupt(struct pt_regs *regs)
 433 {
 434         entering_irq();
 435         __smp_thermal_interrupt();
 436         exiting_ack_irq();
 437 }
 438
 439 asmlinkage __visible void smp_trace_thermal_interrupt(struct pt_regs *regs)
 440 {
 441         entering_irq();
 442         trace_thermal_apic_entry(THERMAL_APIC_VECTOR);
 443         __smp_thermal_interrupt();
 444         trace_thermal_apic_exit(THERMAL_APIC_VECTOR);
 445         exiting_ack_irq();
 446 }
 447
 448 /* Thermal monitoring depends on APIC, ACPI and clock modulation */
 449 static int intel_thermal_supported(struct cpuinfo_x86 *c)
 450 {
 451         if (!cpu_has_apic)
 452                 return 0;
 453         if (!cpu_has(c, X86_FEATURE_ACPI) || !cpu_has(c, X86_FEATURE_ACC))
 454                 return 0;
 455         return 1;
 456 }
 457
 458 void __init mcheck_intel_therm_init(void)
 459 {
 460         /*
 461          * This function is only called on boot CPU. Save the init thermal
 462          * LVT value on BSP and use that value to restore APs' thermal LVT
 463          * entry BIOS programmed later
 464          */
 465         if (intel_thermal_supported(&boot_cpu_data))
 466                 lvtthmr_init = apic_read(APIC_LVTTHMR);
 467 }
 468
 469 void intel_init_thermal(struct cpuinfo_x86 *c)
 470 {
 471         unsigned int cpu = smp_processor_id();
 472         int tm2 = 0;
 473         u32 l, h;
 474
 475         if (!intel_thermal_supported(c))
 476                 return;
 477
 478         /*
 479          * First check if its enabled already, in which case there might
 480          * be some SMM goo which handles it, so we can't even put a handler
 481          * since it might be delivered via SMI already:
 482          */
 483         rdmsr(MSR_IA32_MISC_ENABLE, l, h);
 484
 485         h = lvtthmr_init;
 486         /*
 487          * The initial value of thermal LVT entries on all APs always reads
 488          * 0x10000 because APs are woken up by BSP issuing INIT-SIPI-SIPI
 489          * sequence to them and LVT registers are reset to 0s except for
 490          * the mask bits which are set to 1s when APs receive INIT IPI.
 491          * If BIOS takes over the thermal interrupt and sets its interrupt
 492          * delivery mode to SMI (not fixed), it restores the value that the
 493          * BIOS has programmed on AP based on BSP's info we saved since BIOS
 494          * is always setting the same value for all threads/cores.
 495          */
 496         if ((h & APIC_DM_FIXED_MASK) != APIC_DM_FIXED)
 497                 apic_write(APIC_LVTTHMR, lvtthmr_init);
 498
 499
 500         if ((l & MSR_IA32_MISC_ENABLE_TM1) && (h & APIC_DM_SMI)) {
 501                 if (system_state == SYSTEM_BOOTING)
 502                         printk(KERN_DEBUG "CPU%d: Thermal monitoring handled by SMI\n", cpu);
 503                 return;
 504         }
 505
 506         /* early Pentium M models use different method for enabling TM2 */
 507         if (cpu_has(c, X86_FEATURE_TM2)) {
 508                 if (c->x86 == 6 && (c->x86_model == 9 || c->x86_model == 13)) {
 509                         rdmsr(MSR_THERM2_CTL, l, h);
 510                         if (l & MSR_THERM2_CTL_TM_SELECT)
 511                                 tm2 = 1;
 512                 } else if (l & MSR_IA32_MISC_ENABLE_TM2)
 513                         tm2 = 1;
 514         }
 515
 516         /* We'll mask the thermal vector in the lapic till we're ready: */
 517         h = THERMAL_APIC_VECTOR | APIC_DM_FIXED | APIC_LVT_MASKED;
 518         apic_write(APIC_LVTTHMR, h);
 519
 520         rdmsr(MSR_IA32_THERM_INTERRUPT, l, h);
 521         if (cpu_has(c, X86_FEATURE_PLN) && !int_pln_enable)
 522                 wrmsr(MSR_IA32_THERM_INTERRUPT,
 523                         (l | (THERM_INT_LOW_ENABLE
 524                         | THERM_INT_HIGH_ENABLE)) & ~THERM_INT_PLN_ENABLE, h);
 525         else if (cpu_has(c, X86_FEATURE_PLN) && int_pln_enable)
 526                 wrmsr(MSR_IA32_THERM_INTERRUPT,
 527                         l | (THERM_INT_LOW_ENABLE
 528                         | THERM_INT_HIGH_ENABLE | THERM_INT_PLN_ENABLE), h);
 529         else
 530                 wrmsr(MSR_IA32_THERM_INTERRUPT,
 531                       l | (THERM_INT_LOW_ENABLE | THERM_INT_HIGH_ENABLE), h);
 532
 533         if (cpu_has(c, X86_FEATURE_PTS)) {
 534                 rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
 535                 if (cpu_has(c, X86_FEATURE_PLN) && !int_pln_enable)
 536                         wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
 537                                 (l | (PACKAGE_THERM_INT_LOW_ENABLE
 538                                 | PACKAGE_THERM_INT_HIGH_ENABLE))
 539                                 & ~PACKAGE_THERM_INT_PLN_ENABLE, h);
 540                 else if (cpu_has(c, X86_FEATURE_PLN) && int_pln_enable)
 541                         wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
 542                                 l | (PACKAGE_THERM_INT_LOW_ENABLE
 543                                 | PACKAGE_THERM_INT_HIGH_ENABLE
 544                                 | PACKAGE_THERM_INT_PLN_ENABLE), h);
 545                 else
 546                         wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
 547                               l | (PACKAGE_THERM_INT_LOW_ENABLE
 548                                 | PACKAGE_THERM_INT_HIGH_ENABLE), h);
 549         }
 550
 551         smp_thermal_vector = intel_thermal_interrupt;
 552
 553         rdmsr(MSR_IA32_MISC_ENABLE, l, h);
 554         wrmsr(MSR_IA32_MISC_ENABLE, l | MSR_IA32_MISC_ENABLE_TM1, h);
 555
 556         /* Unmask the thermal vector: */
 557         l = apic_read(APIC_LVTTHMR);
 558         apic_write(APIC_LVTTHMR, l & ~APIC_LVT_MASKED);
 559
 560         printk_once(KERN_INFO "CPU0: Thermal monitoring enabled (%s)\n",
 561                        tm2 ? "TM2" : "TM1");
 562
 563         /* enable thermal throttle processing */
 564         atomic_set(&therm_throt_en, 1);
 565 }