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/system.h>
  29 #include <asm/apic.h>
  30 #include <asm/idle.h>
  31 #include <asm/mce.h>
  32 #include <asm/msr.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 };
  59
  60 /* Callback to handle core threshold interrupts */
  61 int (*platform_thermal_notify)(__u64 msr_val);
  62 EXPORT_SYMBOL(platform_thermal_notify);
  63
  64 static DEFINE_PER_CPU(struct thermal_state, thermal_state);
  65
  66 static atomic_t therm_throt_en  = ATOMIC_INIT(0);
  67
  68 static u32 lvtthmr_init __read_mostly;
  69
  70 #ifdef CONFIG_SYSFS
  71 #define define_therm_throt_device_one_ro(_name)                         \
  72         static DEVICE_ATTR(_name, 0444,                                 \
  73                            therm_throt_device_show_##_name,             \
  74                                    NULL)                                \
  75
  76 #define define_therm_throt_device_show_func(event, name)                \
  77                                                                         \
  78 static ssize_t therm_throt_device_show_##event##_##name(                \
  79                         struct device *dev,                             \
  80                         struct device_attribute *attr,                  \
  81                         char *buf)                                      \
  82 {                                                                       \
  83         unsigned int cpu = dev->id;                                     \
  84         ssize_t ret;                                                    \
  85                                                                         \
  86         preempt_disable();      /* CPU hotplug */                       \
  87         if (cpu_online(cpu)) {                                          \
  88                 ret = sprintf(buf, "%lu\n",                             \
  89                               per_cpu(thermal_state, cpu).event.name);  \
  90         } else                                                          \
  91                 ret = 0;                                                \
  92         preempt_enable();                                               \
  93                                                                         \
  94         return ret;                                                     \
  95 }
  96
  97 define_therm_throt_device_show_func(core_throttle, count);
  98 define_therm_throt_device_one_ro(core_throttle_count);
  99
 100 define_therm_throt_device_show_func(core_power_limit, count);
 101 define_therm_throt_device_one_ro(core_power_limit_count);
 102
 103 define_therm_throt_device_show_func(package_throttle, count);
 104 define_therm_throt_device_one_ro(package_throttle_count);
 105
 106 define_therm_throt_device_show_func(package_power_limit, count);
 107 define_therm_throt_device_one_ro(package_power_limit_count);
 108
 109 static struct attribute *thermal_throttle_attrs[] = {
 110         &dev_attr_core_throttle_count.attr,
 111         NULL
 112 };
 113
 114 static struct attribute_group thermal_attr_group = {
 115         .attrs  = thermal_throttle_attrs,
 116         .name   = "thermal_throttle"
 117 };
 118 #endif /* CONFIG_SYSFS */
 119
 120 #define CORE_LEVEL      0
 121 #define PACKAGE_LEVEL   1
 122
 123 /***
 124  * therm_throt_process - Process thermal throttling event from interrupt
 125  * @curr: Whether the condition is current or not (boolean), since the
 126  *        thermal interrupt normally gets called both when the thermal
 127  *        event begins and once the event has ended.
 128  *
 129  * This function is called by the thermal interrupt after the
 130  * IRQ has been acknowledged.
 131  *
 132  * It will take care of rate limiting and printing messages to the syslog.
 133  *
 134  * Returns: 0 : Event should NOT be further logged, i.e. still in
 135  *              "timeout" from previous log message.
 136  *          1 : Event should be logged further, and a message has been
 137  *              printed to the syslog.
 138  */
 139 static int therm_throt_process(bool new_event, int event, int level)
 140 {
 141         struct _thermal_state *state;
 142         unsigned int this_cpu = smp_processor_id();
 143         bool old_event;
 144         u64 now;
 145         struct thermal_state *pstate = &per_cpu(thermal_state, this_cpu);
 146
 147         now = get_jiffies_64();
 148         if (level == CORE_LEVEL) {
 149                 if (event == THERMAL_THROTTLING_EVENT)
 150                         state = &pstate->core_throttle;
 151                 else if (event == POWER_LIMIT_EVENT)
 152                         state = &pstate->core_power_limit;
 153                 else
 154                          return 0;
 155         } else if (level == PACKAGE_LEVEL) {
 156                 if (event == THERMAL_THROTTLING_EVENT)
 157                         state = &pstate->package_throttle;
 158                 else if (event == POWER_LIMIT_EVENT)
 159                         state = &pstate->package_power_limit;
 160                 else
 161                         return 0;
 162         } else
 163                 return 0;
 164
 165         old_event = state->new_event;
 166         state->new_event = new_event;
 167
 168         if (new_event)
 169                 state->count++;
 170
 171         if (time_before64(now, state->next_check) &&
 172                         state->count != state->last_count)
 173                 return 0;
 174
 175         state->next_check = now + CHECK_INTERVAL;
 176         state->last_count = state->count;
 177
 178         /* if we just entered the thermal event */
 179         if (new_event) {
 180                 if (event == THERMAL_THROTTLING_EVENT)
 181                         printk(KERN_CRIT "CPU%d: %s temperature above threshold, cpu clock throttled (total events = %lu)\n",
 182                                 this_cpu,
 183                                 level == CORE_LEVEL ? "Core" : "Package",
 184                                 state->count);
 185                 else
 186                         printk(KERN_CRIT "CPU%d: %s power limit notification (total events = %lu)\n",
 187                                 this_cpu,
 188                                 level == CORE_LEVEL ? "Core" : "Package",
 189                                 state->count);
 190                 return 1;
 191         }
 192         if (old_event) {
 193                 if (event == THERMAL_THROTTLING_EVENT)
 194                         printk(KERN_INFO "CPU%d: %s temperature/speed normal\n",
 195                                 this_cpu,
 196                                 level == CORE_LEVEL ? "Core" : "Package");
 197                 else
 198                         printk(KERN_INFO "CPU%d: %s power limit normal\n",
 199                                 this_cpu,
 200                                 level == CORE_LEVEL ? "Core" : "Package");
 201                 return 1;
 202         }
 203
 204         return 0;
 205 }
 206
 207 static int thresh_event_valid(int event)
 208 {
 209         struct _thermal_state *state;
 210         unsigned int this_cpu = smp_processor_id();
 211         struct thermal_state *pstate = &per_cpu(thermal_state, this_cpu);
 212         u64 now = get_jiffies_64();
 213
 214         state = (event == 0) ? &pstate->core_thresh0 : &pstate->core_thresh1;
 215
 216         if (time_before64(now, state->next_check))
 217                 return 0;
 218
 219         state->next_check = now + CHECK_INTERVAL;
 220         return 1;
 221 }
 222
 223 #ifdef CONFIG_SYSFS
 224 /* Add/Remove thermal_throttle interface for CPU device: */
 225 static __cpuinit int thermal_throttle_add_dev(struct device *dev,
 226                                 unsigned int cpu)
 227 {
 228         int err;
 229         struct cpuinfo_x86 *c = &cpu_data(cpu);
 230
 231         err = sysfs_create_group(&dev->kobj, &thermal_attr_group);
 232         if (err)
 233                 return err;
 234
 235         if (cpu_has(c, X86_FEATURE_PLN))
 236                 err = sysfs_add_file_to_group(&dev->kobj,
 237                                               &dev_attr_core_power_limit_count.attr,
 238                                               thermal_attr_group.name);
 239         if (cpu_has(c, X86_FEATURE_PTS)) {
 240                 err = sysfs_add_file_to_group(&dev->kobj,
 241                                               &dev_attr_package_throttle_count.attr,
 242                                               thermal_attr_group.name);
 243                 if (cpu_has(c, X86_FEATURE_PLN))
 244                         err = sysfs_add_file_to_group(&dev->kobj,
 245                                         &dev_attr_package_power_limit_count.attr,
 246                                         thermal_attr_group.name);
 247         }
 248
 249         return err;
 250 }
 251
 252 static __cpuinit void thermal_throttle_remove_dev(struct device *dev)
 253 {
 254         sysfs_remove_group(&dev->kobj, &thermal_attr_group);
 255 }
 256
 257 /* Mutex protecting device creation against CPU hotplug: */
 258 static DEFINE_MUTEX(therm_cpu_lock);
 259
 260 /* Get notified when a cpu comes on/off. Be hotplug friendly. */
 261 static __cpuinit int
 262 thermal_throttle_cpu_callback(struct notifier_block *nfb,
 263                               unsigned long action,
 264                               void *hcpu)
 265 {
 266         unsigned int cpu = (unsigned long)hcpu;
 267         struct device *dev;
 268         int err = 0;
 269
 270         dev = get_cpu_device(cpu);
 271
 272         switch (action) {
 273         case CPU_UP_PREPARE:
 274         case CPU_UP_PREPARE_FROZEN:
 275                 mutex_lock(&therm_cpu_lock);
 276                 err = thermal_throttle_add_dev(dev, cpu);
 277                 mutex_unlock(&therm_cpu_lock);
 278                 WARN_ON(err);
 279                 break;
 280         case CPU_UP_CANCELED:
 281         case CPU_UP_CANCELED_FROZEN:
 282         case CPU_DEAD:
 283         case CPU_DEAD_FROZEN:
 284                 mutex_lock(&therm_cpu_lock);
 285                 thermal_throttle_remove_dev(dev);
 286                 mutex_unlock(&therm_cpu_lock);
 287                 break;
 288         }
 289         return notifier_from_errno(err);
 290 }
 291
 292 static struct notifier_block thermal_throttle_cpu_notifier __cpuinitdata =
 293 {
 294         .notifier_call = thermal_throttle_cpu_callback,
 295 };
 296
 297 static __init int thermal_throttle_init_device(void)
 298 {
 299         unsigned int cpu = 0;
 300         int err;
 301
 302         if (!atomic_read(&therm_throt_en))
 303                 return 0;
 304
 305         register_hotcpu_notifier(&thermal_throttle_cpu_notifier);
 306
 307 #ifdef CONFIG_HOTPLUG_CPU
 308         mutex_lock(&therm_cpu_lock);
 309 #endif
 310         /* connect live CPUs to sysfs */
 311         for_each_online_cpu(cpu) {
 312                 err = thermal_throttle_add_dev(get_cpu_device(cpu), cpu);
 313                 WARN_ON(err);
 314         }
 315 #ifdef CONFIG_HOTPLUG_CPU
 316         mutex_unlock(&therm_cpu_lock);
 317 #endif
 318
 319         return 0;
 320 }
 321 device_initcall(thermal_throttle_init_device);
 322
 323 #endif /* CONFIG_SYSFS */
 324
 325 static void notify_thresholds(__u64 msr_val)
 326 {
 327         /* check whether the interrupt handler is defined;
 328          * otherwise simply return
 329          */
 330         if (!platform_thermal_notify)
 331                 return;
 332
 333         /* lower threshold reached */
 334         if ((msr_val & THERM_LOG_THRESHOLD0) && thresh_event_valid(0))
 335                 platform_thermal_notify(msr_val);
 336         /* higher threshold reached */
 337         if ((msr_val & THERM_LOG_THRESHOLD1) && thresh_event_valid(1))
 338                 platform_thermal_notify(msr_val);
 339 }
 340
 341 /* Thermal transition interrupt handler */
 342 static void intel_thermal_interrupt(void)
 343 {
 344         __u64 msr_val;
 345
 346         rdmsrl(MSR_IA32_THERM_STATUS, msr_val);
 347
 348         /* Check for violation of core thermal thresholds*/
 349         notify_thresholds(msr_val);
 350
 351         if (therm_throt_process(msr_val & THERM_STATUS_PROCHOT,
 352                                 THERMAL_THROTTLING_EVENT,
 353                                 CORE_LEVEL) != 0)
 354                 mce_log_therm_throt_event(msr_val);
 355
 356         if (this_cpu_has(X86_FEATURE_PLN))
 357                 therm_throt_process(msr_val & THERM_STATUS_POWER_LIMIT,
 358                                         POWER_LIMIT_EVENT,
 359                                         CORE_LEVEL);
 360
 361         if (this_cpu_has(X86_FEATURE_PTS)) {
 362                 rdmsrl(MSR_IA32_PACKAGE_THERM_STATUS, msr_val);
 363                 therm_throt_process(msr_val & PACKAGE_THERM_STATUS_PROCHOT,
 364                                         THERMAL_THROTTLING_EVENT,
 365                                         PACKAGE_LEVEL);
 366                 if (this_cpu_has(X86_FEATURE_PLN))
 367                         therm_throt_process(msr_val &
 368                                         PACKAGE_THERM_STATUS_POWER_LIMIT,
 369                                         POWER_LIMIT_EVENT,
 370                                         PACKAGE_LEVEL);
 371         }
 372 }
 373
 374 static void unexpected_thermal_interrupt(void)
 375 {
 376         printk(KERN_ERR "CPU%d: Unexpected LVT thermal interrupt!\n",
 377                         smp_processor_id());
 378 }
 379
 380 static void (*smp_thermal_vector)(void) = unexpected_thermal_interrupt;
 381
 382 asmlinkage void smp_thermal_interrupt(struct pt_regs *regs)
 383 {
 384         irq_enter();
 385         exit_idle();
 386         inc_irq_stat(irq_thermal_count);
 387         smp_thermal_vector();
 388         irq_exit();
 389         /* Ack only at the end to avoid potential reentry */
 390         ack_APIC_irq();
 391 }
 392
 393 /* Thermal monitoring depends on APIC, ACPI and clock modulation */
 394 static int intel_thermal_supported(struct cpuinfo_x86 *c)
 395 {
 396         if (!cpu_has_apic)
 397                 return 0;
 398         if (!cpu_has(c, X86_FEATURE_ACPI) || !cpu_has(c, X86_FEATURE_ACC))
 399                 return 0;
 400         return 1;
 401 }
 402
 403 void __init mcheck_intel_therm_init(void)
 404 {
 405         /*
 406          * This function is only called on boot CPU. Save the init thermal
 407          * LVT value on BSP and use that value to restore APs' thermal LVT
 408          * entry BIOS programmed later
 409          */
 410         if (intel_thermal_supported(&boot_cpu_data))
 411                 lvtthmr_init = apic_read(APIC_LVTTHMR);
 412 }
 413
 414 void intel_init_thermal(struct cpuinfo_x86 *c)
 415 {
 416         unsigned int cpu = smp_processor_id();
 417         int tm2 = 0;
 418         u32 l, h;
 419
 420         if (!intel_thermal_supported(c))
 421                 return;
 422
 423         /*
 424          * First check if its enabled already, in which case there might
 425          * be some SMM goo which handles it, so we can't even put a handler
 426          * since it might be delivered via SMI already:
 427          */
 428         rdmsr(MSR_IA32_MISC_ENABLE, l, h);
 429
 430         h = lvtthmr_init;
 431         /*
 432          * The initial value of thermal LVT entries on all APs always reads
 433          * 0x10000 because APs are woken up by BSP issuing INIT-SIPI-SIPI
 434          * sequence to them and LVT registers are reset to 0s except for
 435          * the mask bits which are set to 1s when APs receive INIT IPI.
 436          * If BIOS takes over the thermal interrupt and sets its interrupt
 437          * delivery mode to SMI (not fixed), it restores the value that the
 438          * BIOS has programmed on AP based on BSP's info we saved since BIOS
 439          * is always setting the same value for all threads/cores.
 440          */
 441         if ((h & APIC_DM_FIXED_MASK) != APIC_DM_FIXED)
 442                 apic_write(APIC_LVTTHMR, lvtthmr_init);
 443
 444
 445         if ((l & MSR_IA32_MISC_ENABLE_TM1) && (h & APIC_DM_SMI)) {
 446                 printk(KERN_DEBUG
 447                        "CPU%d: Thermal monitoring handled by SMI\n", cpu);
 448                 return;
 449         }
 450
 451         /* Check whether a vector already exists */
 452         if (h & APIC_VECTOR_MASK) {
 453                 printk(KERN_DEBUG
 454                        "CPU%d: Thermal LVT vector (%#x) already installed\n",
 455                        cpu, (h & APIC_VECTOR_MASK));
 456                 return;
 457         }
 458
 459         /* early Pentium M models use different method for enabling TM2 */
 460         if (cpu_has(c, X86_FEATURE_TM2)) {
 461                 if (c->x86 == 6 && (c->x86_model == 9 || c->x86_model == 13)) {
 462                         rdmsr(MSR_THERM2_CTL, l, h);
 463                         if (l & MSR_THERM2_CTL_TM_SELECT)
 464                                 tm2 = 1;
 465                 } else if (l & MSR_IA32_MISC_ENABLE_TM2)
 466                         tm2 = 1;
 467         }
 468
 469         /* We'll mask the thermal vector in the lapic till we're ready: */
 470         h = THERMAL_APIC_VECTOR | APIC_DM_FIXED | APIC_LVT_MASKED;
 471         apic_write(APIC_LVTTHMR, h);
 472
 473         rdmsr(MSR_IA32_THERM_INTERRUPT, l, h);
 474         if (cpu_has(c, X86_FEATURE_PLN))
 475                 wrmsr(MSR_IA32_THERM_INTERRUPT,
 476                       l | (THERM_INT_LOW_ENABLE
 477                         | THERM_INT_HIGH_ENABLE | THERM_INT_PLN_ENABLE), h);
 478         else
 479                 wrmsr(MSR_IA32_THERM_INTERRUPT,
 480                       l | (THERM_INT_LOW_ENABLE | THERM_INT_HIGH_ENABLE), h);
 481
 482         if (cpu_has(c, X86_FEATURE_PTS)) {
 483                 rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
 484                 if (cpu_has(c, X86_FEATURE_PLN))
 485                         wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
 486                               l | (PACKAGE_THERM_INT_LOW_ENABLE
 487                                 | PACKAGE_THERM_INT_HIGH_ENABLE
 488                                 | PACKAGE_THERM_INT_PLN_ENABLE), h);
 489                 else
 490                         wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
 491                               l | (PACKAGE_THERM_INT_LOW_ENABLE
 492                                 | PACKAGE_THERM_INT_HIGH_ENABLE), h);
 493         }
 494
 495         smp_thermal_vector = intel_thermal_interrupt;
 496
 497         rdmsr(MSR_IA32_MISC_ENABLE, l, h);
 498         wrmsr(MSR_IA32_MISC_ENABLE, l | MSR_IA32_MISC_ENABLE_TM1, h);
 499
 500         /* Unmask the thermal vector: */
 501         l = apic_read(APIC_LVTTHMR);
 502         apic_write(APIC_LVTTHMR, l & ~APIC_LVT_MASKED);
 503
 504         printk_once(KERN_INFO "CPU0: Thermal monitoring enabled (%s)\n",
 505                        tm2 ? "TM2" : "TM1");
 506
 507         /* enable thermal throttle processing */
 508         atomic_set(&therm_throt_en, 1);
 509 }