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/sysdev.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 };
  57
  58 static DEFINE_PER_CPU(struct thermal_state, thermal_state);
  59
  60 static atomic_t therm_throt_en  = ATOMIC_INIT(0);
  61
  62 static u32 lvtthmr_init __read_mostly;
  63
  64 #ifdef CONFIG_SYSFS
  65 #define define_therm_throt_sysdev_one_ro(_name)                         \
  66         static SYSDEV_ATTR(_name, 0444,                                 \
  67                            therm_throt_sysdev_show_##_name,             \
  68                                    NULL)                                \
  69
  70 #define define_therm_throt_sysdev_show_func(event, name)                \
  71                                                                         \
  72 static ssize_t therm_throt_sysdev_show_##event##_##name(                \
  73                         struct sys_device *dev,                         \
  74                         struct sysdev_attribute *attr,                  \
  75                         char *buf)                                      \
  76 {                                                                       \
  77         unsigned int cpu = dev->id;                                     \
  78         ssize_t ret;                                                    \
  79                                                                         \
  80         preempt_disable();      /* CPU hotplug */                       \
  81         if (cpu_online(cpu)) {                                          \
  82                 ret = sprintf(buf, "%lu\n",                             \
  83                               per_cpu(thermal_state, cpu).event.name);  \
  84         } else                                                          \
  85                 ret = 0;                                                \
  86         preempt_enable();                                               \
  87                                                                         \
  88         return ret;                                                     \
  89 }
  90
  91 define_therm_throt_sysdev_show_func(core_throttle, count);
  92 define_therm_throt_sysdev_one_ro(core_throttle_count);
  93
  94 define_therm_throt_sysdev_show_func(core_power_limit, count);
  95 define_therm_throt_sysdev_one_ro(core_power_limit_count);
  96
  97 define_therm_throt_sysdev_show_func(package_throttle, count);
  98 define_therm_throt_sysdev_one_ro(package_throttle_count);
  99
 100 define_therm_throt_sysdev_show_func(package_power_limit, count);
 101 define_therm_throt_sysdev_one_ro(package_power_limit_count);
 102
 103 static struct attribute *thermal_throttle_attrs[] = {
 104         &attr_core_throttle_count.attr,
 105         NULL
 106 };
 107
 108 static struct attribute_group thermal_attr_group = {
 109         .attrs  = thermal_throttle_attrs,
 110         .name   = "thermal_throttle"
 111 };
 112 #endif /* CONFIG_SYSFS */
 113
 114 #define CORE_LEVEL      0
 115 #define PACKAGE_LEVEL   1
 116
 117 /***
 118  * therm_throt_process - Process thermal throttling event from interrupt
 119  * @curr: Whether the condition is current or not (boolean), since the
 120  *        thermal interrupt normally gets called both when the thermal
 121  *        event begins and once the event has ended.
 122  *
 123  * This function is called by the thermal interrupt after the
 124  * IRQ has been acknowledged.
 125  *
 126  * It will take care of rate limiting and printing messages to the syslog.
 127  *
 128  * Returns: 0 : Event should NOT be further logged, i.e. still in
 129  *              "timeout" from previous log message.
 130  *          1 : Event should be logged further, and a message has been
 131  *              printed to the syslog.
 132  */
 133 static int therm_throt_process(bool new_event, int event, int level)
 134 {
 135         struct _thermal_state *state;
 136         unsigned int this_cpu = smp_processor_id();
 137         bool old_event;
 138         u64 now;
 139         struct thermal_state *pstate = &per_cpu(thermal_state, this_cpu);
 140
 141         now = get_jiffies_64();
 142         if (level == CORE_LEVEL) {
 143                 if (event == THERMAL_THROTTLING_EVENT)
 144                         state = &pstate->core_throttle;
 145                 else if (event == POWER_LIMIT_EVENT)
 146                         state = &pstate->core_power_limit;
 147                 else
 148                          return 0;
 149         } else if (level == PACKAGE_LEVEL) {
 150                 if (event == THERMAL_THROTTLING_EVENT)
 151                         state = &pstate->package_throttle;
 152                 else if (event == POWER_LIMIT_EVENT)
 153                         state = &pstate->package_power_limit;
 154                 else
 155                         return 0;
 156         } else
 157                 return 0;
 158
 159         old_event = state->new_event;
 160         state->new_event = new_event;
 161
 162         if (new_event)
 163                 state->count++;
 164
 165         if (time_before64(now, state->next_check) &&
 166                         state->count != state->last_count)
 167                 return 0;
 168
 169         state->next_check = now + CHECK_INTERVAL;
 170         state->last_count = state->count;
 171
 172         /* if we just entered the thermal event */
 173         if (new_event) {
 174                 if (event == THERMAL_THROTTLING_EVENT)
 175                         printk(KERN_CRIT "CPU%d: %s temperature above threshold, cpu clock throttled (total events = %lu)\n",
 176                                 this_cpu,
 177                                 level == CORE_LEVEL ? "Core" : "Package",
 178                                 state->count);
 179                 else
 180                         printk(KERN_CRIT "CPU%d: %s power limit notification (total events = %lu)\n",
 181                                 this_cpu,
 182                                 level == CORE_LEVEL ? "Core" : "Package",
 183                                 state->count);
 184
 185                 add_taint(TAINT_MACHINE_CHECK);
 186                 return 1;
 187         }
 188         if (old_event) {
 189                 if (event == THERMAL_THROTTLING_EVENT)
 190                         printk(KERN_INFO "CPU%d: %s temperature/speed normal\n",
 191                                 this_cpu,
 192                                 level == CORE_LEVEL ? "Core" : "Package");
 193                 else
 194                         printk(KERN_INFO "CPU%d: %s power limit normal\n",
 195                                 this_cpu,
 196                                 level == CORE_LEVEL ? "Core" : "Package");
 197                 return 1;
 198         }
 199
 200         return 0;
 201 }
 202
 203 #ifdef CONFIG_SYSFS
 204 /* Add/Remove thermal_throttle interface for CPU device: */
 205 static __cpuinit int thermal_throttle_add_dev(struct sys_device *sys_dev,
 206                                 unsigned int cpu)
 207 {
 208         int err;
 209         struct cpuinfo_x86 *c = &cpu_data(cpu);
 210
 211         err = sysfs_create_group(&sys_dev->kobj, &thermal_attr_group);
 212         if (err)
 213                 return err;
 214
 215         if (cpu_has(c, X86_FEATURE_PLN))
 216                 err = sysfs_add_file_to_group(&sys_dev->kobj,
 217                                               &attr_core_power_limit_count.attr,
 218                                               thermal_attr_group.name);
 219         if (cpu_has(c, X86_FEATURE_PTS))
 220                 err = sysfs_add_file_to_group(&sys_dev->kobj,
 221                                               &attr_package_throttle_count.attr,
 222                                               thermal_attr_group.name);
 223                 if (cpu_has(c, X86_FEATURE_PLN))
 224                         err = sysfs_add_file_to_group(&sys_dev->kobj,
 225                                         &attr_package_power_limit_count.attr,
 226                                         thermal_attr_group.name);
 227
 228         return err;
 229 }
 230
 231 static __cpuinit void thermal_throttle_remove_dev(struct sys_device *sys_dev)
 232 {
 233         sysfs_remove_group(&sys_dev->kobj, &thermal_attr_group);
 234 }
 235
 236 /* Mutex protecting device creation against CPU hotplug: */
 237 static DEFINE_MUTEX(therm_cpu_lock);
 238
 239 /* Get notified when a cpu comes on/off. Be hotplug friendly. */
 240 static __cpuinit int
 241 thermal_throttle_cpu_callback(struct notifier_block *nfb,
 242                               unsigned long action,
 243                               void *hcpu)
 244 {
 245         unsigned int cpu = (unsigned long)hcpu;
 246         struct sys_device *sys_dev;
 247         int err = 0;
 248
 249         sys_dev = get_cpu_sysdev(cpu);
 250
 251         switch (action) {
 252         case CPU_UP_PREPARE:
 253         case CPU_UP_PREPARE_FROZEN:
 254                 mutex_lock(&therm_cpu_lock);
 255                 err = thermal_throttle_add_dev(sys_dev, cpu);
 256                 mutex_unlock(&therm_cpu_lock);
 257                 WARN_ON(err);
 258                 break;
 259         case CPU_UP_CANCELED:
 260         case CPU_UP_CANCELED_FROZEN:
 261         case CPU_DEAD:
 262         case CPU_DEAD_FROZEN:
 263                 mutex_lock(&therm_cpu_lock);
 264                 thermal_throttle_remove_dev(sys_dev);
 265                 mutex_unlock(&therm_cpu_lock);
 266                 break;
 267         }
 268         return notifier_from_errno(err);
 269 }
 270
 271 static struct notifier_block thermal_throttle_cpu_notifier __cpuinitdata =
 272 {
 273         .notifier_call = thermal_throttle_cpu_callback,
 274 };
 275
 276 static __init int thermal_throttle_init_device(void)
 277 {
 278         unsigned int cpu = 0;
 279         int err;
 280
 281         if (!atomic_read(&therm_throt_en))
 282                 return 0;
 283
 284         register_hotcpu_notifier(&thermal_throttle_cpu_notifier);
 285
 286 #ifdef CONFIG_HOTPLUG_CPU
 287         mutex_lock(&therm_cpu_lock);
 288 #endif
 289         /* connect live CPUs to sysfs */
 290         for_each_online_cpu(cpu) {
 291                 err = thermal_throttle_add_dev(get_cpu_sysdev(cpu), cpu);
 292                 WARN_ON(err);
 293         }
 294 #ifdef CONFIG_HOTPLUG_CPU
 295         mutex_unlock(&therm_cpu_lock);
 296 #endif
 297
 298         return 0;
 299 }
 300 device_initcall(thermal_throttle_init_device);
 301
 302 #endif /* CONFIG_SYSFS */
 303
 304 /*
 305  * Set up the most two significant bit to notify mce log that this thermal
 306  * event type.
 307  * This is a temp solution. May be changed in the future with mce log
 308  * infrasture.
 309  */
 310 #define CORE_THROTTLED          (0)
 311 #define CORE_POWER_LIMIT        ((__u64)1 << 62)
 312 #define PACKAGE_THROTTLED       ((__u64)2 << 62)
 313 #define PACKAGE_POWER_LIMIT     ((__u64)3 << 62)
 314
 315 /* Thermal transition interrupt handler */
 316 static void intel_thermal_interrupt(void)
 317 {
 318         __u64 msr_val;
 319         struct cpuinfo_x86 *c = &cpu_data(smp_processor_id());
 320
 321         rdmsrl(MSR_IA32_THERM_STATUS, msr_val);
 322
 323         if (therm_throt_process(msr_val & THERM_STATUS_PROCHOT,
 324                                 THERMAL_THROTTLING_EVENT,
 325                                 CORE_LEVEL) != 0)
 326                 mce_log_therm_throt_event(CORE_THROTTLED | msr_val);
 327
 328         if (cpu_has(c, X86_FEATURE_PLN))
 329                 if (therm_throt_process(msr_val & THERM_STATUS_POWER_LIMIT,
 330                                         POWER_LIMIT_EVENT,
 331                                         CORE_LEVEL) != 0)
 332                         mce_log_therm_throt_event(CORE_POWER_LIMIT | msr_val);
 333
 334         if (cpu_has(c, X86_FEATURE_PTS)) {
 335                 rdmsrl(MSR_IA32_PACKAGE_THERM_STATUS, msr_val);
 336                 if (therm_throt_process(msr_val & PACKAGE_THERM_STATUS_PROCHOT,
 337                                         THERMAL_THROTTLING_EVENT,
 338                                         PACKAGE_LEVEL) != 0)
 339                         mce_log_therm_throt_event(PACKAGE_THROTTLED | msr_val);
 340                 if (cpu_has(c, X86_FEATURE_PLN))
 341                         if (therm_throt_process(msr_val &
 342                                         PACKAGE_THERM_STATUS_POWER_LIMIT,
 343                                         POWER_LIMIT_EVENT,
 344                                         PACKAGE_LEVEL) != 0)
 345                                 mce_log_therm_throt_event(PACKAGE_POWER_LIMIT
 346                                                           | msr_val);
 347         }
 348 }
 349
 350 static void unexpected_thermal_interrupt(void)
 351 {
 352         printk(KERN_ERR "CPU%d: Unexpected LVT TMR interrupt!\n",
 353                         smp_processor_id());
 354         add_taint(TAINT_MACHINE_CHECK);
 355 }
 356
 357 static void (*smp_thermal_vector)(void) = unexpected_thermal_interrupt;
 358
 359 asmlinkage void smp_thermal_interrupt(struct pt_regs *regs)
 360 {
 361         exit_idle();
 362         irq_enter();
 363         inc_irq_stat(irq_thermal_count);
 364         smp_thermal_vector();
 365         irq_exit();
 366         /* Ack only at the end to avoid potential reentry */
 367         ack_APIC_irq();
 368 }
 369
 370 /* Thermal monitoring depends on APIC, ACPI and clock modulation */
 371 static int intel_thermal_supported(struct cpuinfo_x86 *c)
 372 {
 373         if (!cpu_has_apic)
 374                 return 0;
 375         if (!cpu_has(c, X86_FEATURE_ACPI) || !cpu_has(c, X86_FEATURE_ACC))
 376                 return 0;
 377         return 1;
 378 }
 379
 380 void __init mcheck_intel_therm_init(void)
 381 {
 382         /*
 383          * This function is only called on boot CPU. Save the init thermal
 384          * LVT value on BSP and use that value to restore APs' thermal LVT
 385          * entry BIOS programmed later
 386          */
 387         if (intel_thermal_supported(&boot_cpu_data))
 388                 lvtthmr_init = apic_read(APIC_LVTTHMR);
 389 }
 390
 391 void intel_init_thermal(struct cpuinfo_x86 *c)
 392 {
 393         unsigned int cpu = smp_processor_id();
 394         int tm2 = 0;
 395         u32 l, h;
 396
 397         if (!intel_thermal_supported(c))
 398                 return;
 399
 400         /*
 401          * First check if its enabled already, in which case there might
 402          * be some SMM goo which handles it, so we can't even put a handler
 403          * since it might be delivered via SMI already:
 404          */
 405         rdmsr(MSR_IA32_MISC_ENABLE, l, h);
 406
 407         /*
 408          * The initial value of thermal LVT entries on all APs always reads
 409          * 0x10000 because APs are woken up by BSP issuing INIT-SIPI-SIPI
 410          * sequence to them and LVT registers are reset to 0s except for
 411          * the mask bits which are set to 1s when APs receive INIT IPI.
 412          * Always restore the value that BIOS has programmed on AP based on
 413          * BSP's info we saved since BIOS is always setting the same value
 414          * for all threads/cores
 415          */
 416         apic_write(APIC_LVTTHMR, lvtthmr_init);
 417
 418         h = lvtthmr_init;
 419
 420         if ((l & MSR_IA32_MISC_ENABLE_TM1) && (h & APIC_DM_SMI)) {
 421                 printk(KERN_DEBUG
 422                        "CPU%d: Thermal monitoring handled by SMI\n", cpu);
 423                 return;
 424         }
 425
 426         /* Check whether a vector already exists */
 427         if (h & APIC_VECTOR_MASK) {
 428                 printk(KERN_DEBUG
 429                        "CPU%d: Thermal LVT vector (%#x) already installed\n",
 430                        cpu, (h & APIC_VECTOR_MASK));
 431                 return;
 432         }
 433
 434         /* early Pentium M models use different method for enabling TM2 */
 435         if (cpu_has(c, X86_FEATURE_TM2)) {
 436                 if (c->x86 == 6 && (c->x86_model == 9 || c->x86_model == 13)) {
 437                         rdmsr(MSR_THERM2_CTL, l, h);
 438                         if (l & MSR_THERM2_CTL_TM_SELECT)
 439                                 tm2 = 1;
 440                 } else if (l & MSR_IA32_MISC_ENABLE_TM2)
 441                         tm2 = 1;
 442         }
 443
 444         /* We'll mask the thermal vector in the lapic till we're ready: */
 445         h = THERMAL_APIC_VECTOR | APIC_DM_FIXED | APIC_LVT_MASKED;
 446         apic_write(APIC_LVTTHMR, h);
 447
 448         rdmsr(MSR_IA32_THERM_INTERRUPT, l, h);
 449         if (cpu_has(c, X86_FEATURE_PLN))
 450                 wrmsr(MSR_IA32_THERM_INTERRUPT,
 451                       l | (THERM_INT_LOW_ENABLE
 452                         | THERM_INT_HIGH_ENABLE | THERM_INT_PLN_ENABLE), h);
 453         else
 454                 wrmsr(MSR_IA32_THERM_INTERRUPT,
 455                       l | (THERM_INT_LOW_ENABLE | THERM_INT_HIGH_ENABLE), h);
 456
 457         if (cpu_has(c, X86_FEATURE_PTS)) {
 458                 rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
 459                 if (cpu_has(c, X86_FEATURE_PLN))
 460                         wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
 461                               l | (PACKAGE_THERM_INT_LOW_ENABLE
 462                                 | PACKAGE_THERM_INT_HIGH_ENABLE
 463                                 | PACKAGE_THERM_INT_PLN_ENABLE), h);
 464                 else
 465                         wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
 466                               l | (PACKAGE_THERM_INT_LOW_ENABLE
 467                                 | PACKAGE_THERM_INT_HIGH_ENABLE), h);
 468         }
 469
 470         smp_thermal_vector = intel_thermal_interrupt;
 471
 472         rdmsr(MSR_IA32_MISC_ENABLE, l, h);
 473         wrmsr(MSR_IA32_MISC_ENABLE, l | MSR_IA32_MISC_ENABLE_TM1, h);
 474
 475         /* Unmask the thermal vector: */
 476         l = apic_read(APIC_LVTTHMR);
 477         apic_write(APIC_LVTTHMR, l & ~APIC_LVT_MASKED);
 478
 479         printk_once(KERN_INFO "CPU0: Thermal monitoring enabled (%s)\n",
 480                        tm2 ? "TM2" : "TM1");
 481
 482         /* enable thermal throttle processing */
 483         atomic_set(&therm_throt_en, 1);
 484 }