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