6f8c5e9da97f0f3e4c0ac89557a3b2f1c3a5f01e
[linux-2.6.git] / 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         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_sysdev_one_ro(_name)                         \
72         static SYSDEV_ATTR(_name, 0444,                                 \
73                            therm_throt_sysdev_show_##_name,             \
74                                    NULL)                                \
75
76 #define define_therm_throt_sysdev_show_func(event, name)                \
77                                                                         \
78 static ssize_t therm_throt_sysdev_show_##event##_##name(                \
79                         struct sys_device *dev,                         \
80                         struct sysdev_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_sysdev_show_func(core_throttle, count);
98 define_therm_throt_sysdev_one_ro(core_throttle_count);
99
100 define_therm_throt_sysdev_show_func(core_power_limit, count);
101 define_therm_throt_sysdev_one_ro(core_power_limit_count);
102
103 define_therm_throt_sysdev_show_func(package_throttle, count);
104 define_therm_throt_sysdev_one_ro(package_throttle_count);
105
106 define_therm_throt_sysdev_show_func(package_power_limit, count);
107 define_therm_throt_sysdev_one_ro(package_power_limit_count);
108
109 static struct attribute *thermal_throttle_attrs[] = {
110         &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
191                 add_taint(TAINT_MACHINE_CHECK);
192                 return 1;
193         }
194         if (old_event) {
195                 if (event == THERMAL_THROTTLING_EVENT)
196                         printk(KERN_INFO "CPU%d: %s temperature/speed normal\n",
197                                 this_cpu,
198                                 level == CORE_LEVEL ? "Core" : "Package");
199                 else
200                         printk(KERN_INFO "CPU%d: %s power limit normal\n",
201                                 this_cpu,
202                                 level == CORE_LEVEL ? "Core" : "Package");
203                 return 1;
204         }
205
206         return 0;
207 }
208
209 static int thresh_event_valid(int event)
210 {
211         struct _thermal_state *state;
212         unsigned int this_cpu = smp_processor_id();
213         struct thermal_state *pstate = &per_cpu(thermal_state, this_cpu);
214         u64 now = get_jiffies_64();
215
216         state = (event == 0) ? &pstate->core_thresh0 : &pstate->core_thresh1;
217
218         if (time_before64(now, state->next_check))
219                 return 0;
220
221         state->next_check = now + CHECK_INTERVAL;
222         return 1;
223 }
224
225 #ifdef CONFIG_SYSFS
226 /* Add/Remove thermal_throttle interface for CPU device: */
227 static __cpuinit int thermal_throttle_add_dev(struct sys_device *sys_dev,
228                                 unsigned int cpu)
229 {
230         int err;
231         struct cpuinfo_x86 *c = &cpu_data(cpu);
232
233         err = sysfs_create_group(&sys_dev->kobj, &thermal_attr_group);
234         if (err)
235                 return err;
236
237         if (cpu_has(c, X86_FEATURE_PLN))
238                 err = sysfs_add_file_to_group(&sys_dev->kobj,
239                                               &attr_core_power_limit_count.attr,
240                                               thermal_attr_group.name);
241         if (cpu_has(c, X86_FEATURE_PTS)) {
242                 err = sysfs_add_file_to_group(&sys_dev->kobj,
243                                               &attr_package_throttle_count.attr,
244                                               thermal_attr_group.name);
245                 if (cpu_has(c, X86_FEATURE_PLN))
246                         err = sysfs_add_file_to_group(&sys_dev->kobj,
247                                         &attr_package_power_limit_count.attr,
248                                         thermal_attr_group.name);
249         }
250
251         return err;
252 }
253
254 static __cpuinit void thermal_throttle_remove_dev(struct sys_device *sys_dev)
255 {
256         sysfs_remove_group(&sys_dev->kobj, &thermal_attr_group);
257 }
258
259 /* Mutex protecting device creation against CPU hotplug: */
260 static DEFINE_MUTEX(therm_cpu_lock);
261
262 /* Get notified when a cpu comes on/off. Be hotplug friendly. */
263 static __cpuinit int
264 thermal_throttle_cpu_callback(struct notifier_block *nfb,
265                               unsigned long action,
266                               void *hcpu)
267 {
268         unsigned int cpu = (unsigned long)hcpu;
269         struct sys_device *sys_dev;
270         int err = 0;
271
272         sys_dev = get_cpu_sysdev(cpu);
273
274         switch (action) {
275         case CPU_UP_PREPARE:
276         case CPU_UP_PREPARE_FROZEN:
277                 mutex_lock(&therm_cpu_lock);
278                 err = thermal_throttle_add_dev(sys_dev, cpu);
279                 mutex_unlock(&therm_cpu_lock);
280                 WARN_ON(err);
281                 break;
282         case CPU_UP_CANCELED:
283         case CPU_UP_CANCELED_FROZEN:
284         case CPU_DEAD:
285         case CPU_DEAD_FROZEN:
286                 mutex_lock(&therm_cpu_lock);
287                 thermal_throttle_remove_dev(sys_dev);
288                 mutex_unlock(&therm_cpu_lock);
289                 break;
290         }
291         return notifier_from_errno(err);
292 }
293
294 static struct notifier_block thermal_throttle_cpu_notifier __cpuinitdata =
295 {
296         .notifier_call = thermal_throttle_cpu_callback,
297 };
298
299 static __init int thermal_throttle_init_device(void)
300 {
301         unsigned int cpu = 0;
302         int err;
303
304         if (!atomic_read(&therm_throt_en))
305                 return 0;
306
307         register_hotcpu_notifier(&thermal_throttle_cpu_notifier);
308
309 #ifdef CONFIG_HOTPLUG_CPU
310         mutex_lock(&therm_cpu_lock);
311 #endif
312         /* connect live CPUs to sysfs */
313         for_each_online_cpu(cpu) {
314                 err = thermal_throttle_add_dev(get_cpu_sysdev(cpu), cpu);
315                 WARN_ON(err);
316         }
317 #ifdef CONFIG_HOTPLUG_CPU
318         mutex_unlock(&therm_cpu_lock);
319 #endif
320
321         return 0;
322 }
323 device_initcall(thermal_throttle_init_device);
324
325 #endif /* CONFIG_SYSFS */
326
327 /*
328  * Set up the most two significant bit to notify mce log that this thermal
329  * event type.
330  * This is a temp solution. May be changed in the future with mce log
331  * infrasture.
332  */
333 #define CORE_THROTTLED          (0)
334 #define CORE_POWER_LIMIT        ((__u64)1 << 62)
335 #define PACKAGE_THROTTLED       ((__u64)2 << 62)
336 #define PACKAGE_POWER_LIMIT     ((__u64)3 << 62)
337
338 static void notify_thresholds(__u64 msr_val)
339 {
340         /* check whether the interrupt handler is defined;
341          * otherwise simply return
342          */
343         if (!platform_thermal_notify)
344                 return;
345
346         /* lower threshold reached */
347         if ((msr_val & THERM_LOG_THRESHOLD0) && thresh_event_valid(0))
348                 platform_thermal_notify(msr_val);
349         /* higher threshold reached */
350         if ((msr_val & THERM_LOG_THRESHOLD1) && thresh_event_valid(1))
351                 platform_thermal_notify(msr_val);
352 }
353
354 /* Thermal transition interrupt handler */
355 static void intel_thermal_interrupt(void)
356 {
357         __u64 msr_val;
358         struct cpuinfo_x86 *c = &cpu_data(smp_processor_id());
359
360         rdmsrl(MSR_IA32_THERM_STATUS, msr_val);
361
362         /* Check for violation of core thermal thresholds*/
363         notify_thresholds(msr_val);
364
365         if (therm_throt_process(msr_val & THERM_STATUS_PROCHOT,
366                                 THERMAL_THROTTLING_EVENT,
367                                 CORE_LEVEL) != 0)
368                 mce_log_therm_throt_event(CORE_THROTTLED | msr_val);
369
370         if (cpu_has(c, X86_FEATURE_PLN))
371                 if (therm_throt_process(msr_val & THERM_STATUS_POWER_LIMIT,
372                                         POWER_LIMIT_EVENT,
373                                         CORE_LEVEL) != 0)
374                         mce_log_therm_throt_event(CORE_POWER_LIMIT | msr_val);
375
376         if (cpu_has(c, X86_FEATURE_PTS)) {
377                 rdmsrl(MSR_IA32_PACKAGE_THERM_STATUS, msr_val);
378                 if (therm_throt_process(msr_val & PACKAGE_THERM_STATUS_PROCHOT,
379                                         THERMAL_THROTTLING_EVENT,
380                                         PACKAGE_LEVEL) != 0)
381                         mce_log_therm_throt_event(PACKAGE_THROTTLED | msr_val);
382                 if (cpu_has(c, X86_FEATURE_PLN))
383                         if (therm_throt_process(msr_val &
384                                         PACKAGE_THERM_STATUS_POWER_LIMIT,
385                                         POWER_LIMIT_EVENT,
386                                         PACKAGE_LEVEL) != 0)
387                                 mce_log_therm_throt_event(PACKAGE_POWER_LIMIT
388                                                           | msr_val);
389         }
390 }
391
392 static void unexpected_thermal_interrupt(void)
393 {
394         printk(KERN_ERR "CPU%d: Unexpected LVT thermal interrupt!\n",
395                         smp_processor_id());
396         add_taint(TAINT_MACHINE_CHECK);
397 }
398
399 static void (*smp_thermal_vector)(void) = unexpected_thermal_interrupt;
400
401 asmlinkage void smp_thermal_interrupt(struct pt_regs *regs)
402 {
403         exit_idle();
404         irq_enter();
405         inc_irq_stat(irq_thermal_count);
406         smp_thermal_vector();
407         irq_exit();
408         /* Ack only at the end to avoid potential reentry */
409         ack_APIC_irq();
410 }
411
412 /* Thermal monitoring depends on APIC, ACPI and clock modulation */
413 static int intel_thermal_supported(struct cpuinfo_x86 *c)
414 {
415         if (!cpu_has_apic)
416                 return 0;
417         if (!cpu_has(c, X86_FEATURE_ACPI) || !cpu_has(c, X86_FEATURE_ACC))
418                 return 0;
419         return 1;
420 }
421
422 void __init mcheck_intel_therm_init(void)
423 {
424         /*
425          * This function is only called on boot CPU. Save the init thermal
426          * LVT value on BSP and use that value to restore APs' thermal LVT
427          * entry BIOS programmed later
428          */
429         if (intel_thermal_supported(&boot_cpu_data))
430                 lvtthmr_init = apic_read(APIC_LVTTHMR);
431 }
432
433 void intel_init_thermal(struct cpuinfo_x86 *c)
434 {
435         unsigned int cpu = smp_processor_id();
436         int tm2 = 0;
437         u32 l, h;
438
439         if (!intel_thermal_supported(c))
440                 return;
441
442         /*
443          * First check if its enabled already, in which case there might
444          * be some SMM goo which handles it, so we can't even put a handler
445          * since it might be delivered via SMI already:
446          */
447         rdmsr(MSR_IA32_MISC_ENABLE, l, h);
448
449         /*
450          * The initial value of thermal LVT entries on all APs always reads
451          * 0x10000 because APs are woken up by BSP issuing INIT-SIPI-SIPI
452          * sequence to them and LVT registers are reset to 0s except for
453          * the mask bits which are set to 1s when APs receive INIT IPI.
454          * Always restore the value that BIOS has programmed on AP based on
455          * BSP's info we saved since BIOS is always setting the same value
456          * for all threads/cores
457          */
458         apic_write(APIC_LVTTHMR, lvtthmr_init);
459
460         h = lvtthmr_init;
461
462         if ((l & MSR_IA32_MISC_ENABLE_TM1) && (h & APIC_DM_SMI)) {
463                 printk(KERN_DEBUG
464                        "CPU%d: Thermal monitoring handled by SMI\n", cpu);
465                 return;
466         }
467
468         /* Check whether a vector already exists */
469         if (h & APIC_VECTOR_MASK) {
470                 printk(KERN_DEBUG
471                        "CPU%d: Thermal LVT vector (%#x) already installed\n",
472                        cpu, (h & APIC_VECTOR_MASK));
473                 return;
474         }
475
476         /* early Pentium M models use different method for enabling TM2 */
477         if (cpu_has(c, X86_FEATURE_TM2)) {
478                 if (c->x86 == 6 && (c->x86_model == 9 || c->x86_model == 13)) {
479                         rdmsr(MSR_THERM2_CTL, l, h);
480                         if (l & MSR_THERM2_CTL_TM_SELECT)
481                                 tm2 = 1;
482                 } else if (l & MSR_IA32_MISC_ENABLE_TM2)
483                         tm2 = 1;
484         }
485
486         /* We'll mask the thermal vector in the lapic till we're ready: */
487         h = THERMAL_APIC_VECTOR | APIC_DM_FIXED | APIC_LVT_MASKED;
488         apic_write(APIC_LVTTHMR, h);
489
490         rdmsr(MSR_IA32_THERM_INTERRUPT, l, h);
491         if (cpu_has(c, X86_FEATURE_PLN))
492                 wrmsr(MSR_IA32_THERM_INTERRUPT,
493                       l | (THERM_INT_LOW_ENABLE
494                         | THERM_INT_HIGH_ENABLE | THERM_INT_PLN_ENABLE), h);
495         else
496                 wrmsr(MSR_IA32_THERM_INTERRUPT,
497                       l | (THERM_INT_LOW_ENABLE | THERM_INT_HIGH_ENABLE), h);
498
499         if (cpu_has(c, X86_FEATURE_PTS)) {
500                 rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
501                 if (cpu_has(c, X86_FEATURE_PLN))
502                         wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
503                               l | (PACKAGE_THERM_INT_LOW_ENABLE
504                                 | PACKAGE_THERM_INT_HIGH_ENABLE
505                                 | PACKAGE_THERM_INT_PLN_ENABLE), h);
506                 else
507                         wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
508                               l | (PACKAGE_THERM_INT_LOW_ENABLE
509                                 | PACKAGE_THERM_INT_HIGH_ENABLE), h);
510         }
511
512         smp_thermal_vector = intel_thermal_interrupt;
513
514         rdmsr(MSR_IA32_MISC_ENABLE, l, h);
515         wrmsr(MSR_IA32_MISC_ENABLE, l | MSR_IA32_MISC_ENABLE_TM1, h);
516
517         /* Unmask the thermal vector: */
518         l = apic_read(APIC_LVTTHMR);
519         apic_write(APIC_LVTTHMR, l & ~APIC_LVT_MASKED);
520
521         printk_once(KERN_INFO "CPU0: Thermal monitoring enabled (%s)\n",
522                        tm2 ? "TM2" : "TM1");
523
524         /* enable thermal throttle processing */
525         atomic_set(&therm_throt_en, 1);
526 }