Merge branch 'x86-hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[sfrench/cifs-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 };
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 {
207         int err;
208         struct cpuinfo_x86 *c = &cpu_data(smp_processor_id());
209
210         err = sysfs_create_group(&sys_dev->kobj, &thermal_attr_group);
211         if (err)
212                 return err;
213
214         if (cpu_has(c, X86_FEATURE_PLN))
215                 err = sysfs_add_file_to_group(&sys_dev->kobj,
216                                               &attr_core_power_limit_count.attr,
217                                               thermal_attr_group.name);
218         if (cpu_has(c, X86_FEATURE_PTS))
219                 err = sysfs_add_file_to_group(&sys_dev->kobj,
220                                               &attr_package_throttle_count.attr,
221                                               thermal_attr_group.name);
222                 if (cpu_has(c, X86_FEATURE_PLN))
223                         err = sysfs_add_file_to_group(&sys_dev->kobj,
224                                         &attr_package_power_limit_count.attr,
225                                         thermal_attr_group.name);
226
227         return err;
228 }
229
230 static __cpuinit void thermal_throttle_remove_dev(struct sys_device *sys_dev)
231 {
232         sysfs_remove_group(&sys_dev->kobj, &thermal_attr_group);
233 }
234
235 /* Mutex protecting device creation against CPU hotplug: */
236 static DEFINE_MUTEX(therm_cpu_lock);
237
238 /* Get notified when a cpu comes on/off. Be hotplug friendly. */
239 static __cpuinit int
240 thermal_throttle_cpu_callback(struct notifier_block *nfb,
241                               unsigned long action,
242                               void *hcpu)
243 {
244         unsigned int cpu = (unsigned long)hcpu;
245         struct sys_device *sys_dev;
246         int err = 0;
247
248         sys_dev = get_cpu_sysdev(cpu);
249
250         switch (action) {
251         case CPU_UP_PREPARE:
252         case CPU_UP_PREPARE_FROZEN:
253                 mutex_lock(&therm_cpu_lock);
254                 err = thermal_throttle_add_dev(sys_dev);
255                 mutex_unlock(&therm_cpu_lock);
256                 WARN_ON(err);
257                 break;
258         case CPU_UP_CANCELED:
259         case CPU_UP_CANCELED_FROZEN:
260         case CPU_DEAD:
261         case CPU_DEAD_FROZEN:
262                 mutex_lock(&therm_cpu_lock);
263                 thermal_throttle_remove_dev(sys_dev);
264                 mutex_unlock(&therm_cpu_lock);
265                 break;
266         }
267         return notifier_from_errno(err);
268 }
269
270 static struct notifier_block thermal_throttle_cpu_notifier __cpuinitdata =
271 {
272         .notifier_call = thermal_throttle_cpu_callback,
273 };
274
275 static __init int thermal_throttle_init_device(void)
276 {
277         unsigned int cpu = 0;
278         int err;
279
280         if (!atomic_read(&therm_throt_en))
281                 return 0;
282
283         register_hotcpu_notifier(&thermal_throttle_cpu_notifier);
284
285 #ifdef CONFIG_HOTPLUG_CPU
286         mutex_lock(&therm_cpu_lock);
287 #endif
288         /* connect live CPUs to sysfs */
289         for_each_online_cpu(cpu) {
290                 err = thermal_throttle_add_dev(get_cpu_sysdev(cpu));
291                 WARN_ON(err);
292         }
293 #ifdef CONFIG_HOTPLUG_CPU
294         mutex_unlock(&therm_cpu_lock);
295 #endif
296
297         return 0;
298 }
299 device_initcall(thermal_throttle_init_device);
300
301 #endif /* CONFIG_SYSFS */
302
303 /*
304  * Set up the most two significant bit to notify mce log that this thermal
305  * event type.
306  * This is a temp solution. May be changed in the future with mce log
307  * infrasture.
308  */
309 #define CORE_THROTTLED          (0)
310 #define CORE_POWER_LIMIT        ((__u64)1 << 62)
311 #define PACKAGE_THROTTLED       ((__u64)2 << 62)
312 #define PACKAGE_POWER_LIMIT     ((__u64)3 << 62)
313
314 /* Thermal transition interrupt handler */
315 static void intel_thermal_interrupt(void)
316 {
317         __u64 msr_val;
318         struct cpuinfo_x86 *c = &cpu_data(smp_processor_id());
319
320         rdmsrl(MSR_IA32_THERM_STATUS, msr_val);
321
322         if (therm_throt_process(msr_val & THERM_STATUS_PROCHOT,
323                                 THERMAL_THROTTLING_EVENT,
324                                 CORE_LEVEL) != 0)
325                 mce_log_therm_throt_event(CORE_THROTTLED | msr_val);
326
327         if (cpu_has(c, X86_FEATURE_PLN))
328                 if (therm_throt_process(msr_val & THERM_STATUS_POWER_LIMIT,
329                                         POWER_LIMIT_EVENT,
330                                         CORE_LEVEL) != 0)
331                         mce_log_therm_throt_event(CORE_POWER_LIMIT | msr_val);
332
333         if (cpu_has(c, X86_FEATURE_PTS)) {
334                 rdmsrl(MSR_IA32_PACKAGE_THERM_STATUS, msr_val);
335                 if (therm_throt_process(msr_val & PACKAGE_THERM_STATUS_PROCHOT,
336                                         THERMAL_THROTTLING_EVENT,
337                                         PACKAGE_LEVEL) != 0)
338                         mce_log_therm_throt_event(PACKAGE_THROTTLED | msr_val);
339                 if (cpu_has(c, X86_FEATURE_PLN))
340                         if (therm_throt_process(msr_val &
341                                         PACKAGE_THERM_STATUS_POWER_LIMIT,
342                                         POWER_LIMIT_EVENT,
343                                         PACKAGE_LEVEL) != 0)
344                                 mce_log_therm_throt_event(PACKAGE_POWER_LIMIT
345                                                           | msr_val);
346         }
347 }
348
349 static void unexpected_thermal_interrupt(void)
350 {
351         printk(KERN_ERR "CPU%d: Unexpected LVT TMR interrupt!\n",
352                         smp_processor_id());
353         add_taint(TAINT_MACHINE_CHECK);
354 }
355
356 static void (*smp_thermal_vector)(void) = unexpected_thermal_interrupt;
357
358 asmlinkage void smp_thermal_interrupt(struct pt_regs *regs)
359 {
360         exit_idle();
361         irq_enter();
362         inc_irq_stat(irq_thermal_count);
363         smp_thermal_vector();
364         irq_exit();
365         /* Ack only at the end to avoid potential reentry */
366         ack_APIC_irq();
367 }
368
369 /* Thermal monitoring depends on APIC, ACPI and clock modulation */
370 static int intel_thermal_supported(struct cpuinfo_x86 *c)
371 {
372         if (!cpu_has_apic)
373                 return 0;
374         if (!cpu_has(c, X86_FEATURE_ACPI) || !cpu_has(c, X86_FEATURE_ACC))
375                 return 0;
376         return 1;
377 }
378
379 void __init mcheck_intel_therm_init(void)
380 {
381         /*
382          * This function is only called on boot CPU. Save the init thermal
383          * LVT value on BSP and use that value to restore APs' thermal LVT
384          * entry BIOS programmed later
385          */
386         if (intel_thermal_supported(&boot_cpu_data))
387                 lvtthmr_init = apic_read(APIC_LVTTHMR);
388 }
389
390 void intel_init_thermal(struct cpuinfo_x86 *c)
391 {
392         unsigned int cpu = smp_processor_id();
393         int tm2 = 0;
394         u32 l, h;
395
396         if (!intel_thermal_supported(c))
397                 return;
398
399         /*
400          * First check if its enabled already, in which case there might
401          * be some SMM goo which handles it, so we can't even put a handler
402          * since it might be delivered via SMI already:
403          */
404         rdmsr(MSR_IA32_MISC_ENABLE, l, h);
405
406         /*
407          * The initial value of thermal LVT entries on all APs always reads
408          * 0x10000 because APs are woken up by BSP issuing INIT-SIPI-SIPI
409          * sequence to them and LVT registers are reset to 0s except for
410          * the mask bits which are set to 1s when APs receive INIT IPI.
411          * Always restore the value that BIOS has programmed on AP based on
412          * BSP's info we saved since BIOS is always setting the same value
413          * for all threads/cores
414          */
415         apic_write(APIC_LVTTHMR, lvtthmr_init);
416
417         h = lvtthmr_init;
418
419         if ((l & MSR_IA32_MISC_ENABLE_TM1) && (h & APIC_DM_SMI)) {
420                 printk(KERN_DEBUG
421                        "CPU%d: Thermal monitoring handled by SMI\n", cpu);
422                 return;
423         }
424
425         /* Check whether a vector already exists */
426         if (h & APIC_VECTOR_MASK) {
427                 printk(KERN_DEBUG
428                        "CPU%d: Thermal LVT vector (%#x) already installed\n",
429                        cpu, (h & APIC_VECTOR_MASK));
430                 return;
431         }
432
433         /* early Pentium M models use different method for enabling TM2 */
434         if (cpu_has(c, X86_FEATURE_TM2)) {
435                 if (c->x86 == 6 && (c->x86_model == 9 || c->x86_model == 13)) {
436                         rdmsr(MSR_THERM2_CTL, l, h);
437                         if (l & MSR_THERM2_CTL_TM_SELECT)
438                                 tm2 = 1;
439                 } else if (l & MSR_IA32_MISC_ENABLE_TM2)
440                         tm2 = 1;
441         }
442
443         /* We'll mask the thermal vector in the lapic till we're ready: */
444         h = THERMAL_APIC_VECTOR | APIC_DM_FIXED | APIC_LVT_MASKED;
445         apic_write(APIC_LVTTHMR, h);
446
447         rdmsr(MSR_IA32_THERM_INTERRUPT, l, h);
448         if (cpu_has(c, X86_FEATURE_PLN))
449                 wrmsr(MSR_IA32_THERM_INTERRUPT,
450                       l | (THERM_INT_LOW_ENABLE
451                         | THERM_INT_HIGH_ENABLE | THERM_INT_PLN_ENABLE), h);
452         else
453                 wrmsr(MSR_IA32_THERM_INTERRUPT,
454                       l | (THERM_INT_LOW_ENABLE | THERM_INT_HIGH_ENABLE), h);
455
456         if (cpu_has(c, X86_FEATURE_PTS)) {
457                 rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
458                 if (cpu_has(c, X86_FEATURE_PLN))
459                         wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
460                               l | (PACKAGE_THERM_INT_LOW_ENABLE
461                                 | PACKAGE_THERM_INT_HIGH_ENABLE
462                                 | PACKAGE_THERM_INT_PLN_ENABLE), h);
463                 else
464                         wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
465                               l | (PACKAGE_THERM_INT_LOW_ENABLE
466                                 | PACKAGE_THERM_INT_HIGH_ENABLE), h);
467         }
468
469         smp_thermal_vector = intel_thermal_interrupt;
470
471         rdmsr(MSR_IA32_MISC_ENABLE, l, h);
472         wrmsr(MSR_IA32_MISC_ENABLE, l | MSR_IA32_MISC_ENABLE_TM1, h);
473
474         /* Unmask the thermal vector: */
475         l = apic_read(APIC_LVTTHMR);
476         apic_write(APIC_LVTTHMR, l & ~APIC_LVT_MASKED);
477
478         printk_once(KERN_INFO "CPU0: Thermal monitoring enabled (%s)\n",
479                        tm2 ? "TM2" : "TM1");
480
481         /* enable thermal throttle processing */
482         atomic_set(&therm_throt_en, 1);
483 }