1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * x86_pkg_temp_thermal driver
4 * Copyright (c) 2013, Intel Corporation.
5 */
6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7
8 #include <linux/module.h>
9 #include <linux/init.h>
10 #include <linux/err.h>
11 #include <linux/param.h>
12 #include <linux/device.h>
13 #include <linux/platform_device.h>
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/slab.h>
17 #include <linux/pm.h>
18 #include <linux/thermal.h>
19 #include <linux/debugfs.h>
20 #include <asm/cpu_device_id.h>
21 #include <asm/mce.h>
22
23 /*
24 * Rate control delay: Idea is to introduce denounce effect
25 * This should be long enough to avoid reduce events, when
26 * threshold is set to a temperature, which is constantly
27 * violated, but at the short enough to take any action.
28 * The action can be remove threshold or change it to next
29 * interesting setting. Based on experiments, in around
30 * every 5 seconds under load will give us a significant
31 * temperature change.
32 */
33 #define PKG_TEMP_THERMAL_NOTIFY_DELAY 5000
34 static int notify_delay_ms = PKG_TEMP_THERMAL_NOTIFY_DELAY;
35 module_param(notify_delay_ms, int, 0644);
36 MODULE_PARM_DESC(notify_delay_ms,
37 "User space notification delay in milli seconds.");
38
39 /* Number of trip points in thermal zone. Currently it can't
40 * be more than 2. MSR can allow setting and getting notifications
41 * for only 2 thresholds. This define enforces this, if there
42 * is some wrong values returned by cpuid for number of thresholds.
43 */
44 #define MAX_NUMBER_OF_TRIPS 2
45
46 struct zone_device {
47 int cpu;
48 bool work_scheduled;
49 u32 tj_max;
50 u32 msr_pkg_therm_low;
51 u32 msr_pkg_therm_high;
52 struct delayed_work work;
53 struct thermal_zone_device *tzone;
54 struct cpumask cpumask;
55 };
56
57 static struct thermal_zone_params pkg_temp_tz_params = {
58 .no_hwmon = true,
59 };
60
61 /* Keep track of how many zone pointers we allocated in init() */
62 static int max_id __read_mostly;
63 /* Array of zone pointers */
64 static struct zone_device **zones;
65 /* Serializes interrupt notification, work and hotplug */
66 static DEFINE_RAW_SPINLOCK(pkg_temp_lock);
67 /* Protects zone operation in the work function against hotplug removal */
68 static DEFINE_MUTEX(thermal_zone_mutex);
69
70 /* The dynamically assigned cpu hotplug state for module_exit() */
71 static enum cpuhp_state pkg_thermal_hp_state __read_mostly;
72
73 /* Debug counters to show using debugfs */
74 static struct dentry *debugfs;
75 static unsigned int pkg_interrupt_cnt;
76 static unsigned int pkg_work_cnt;
77
pkg_temp_debugfs_init(void)78 static void pkg_temp_debugfs_init(void)
79 {
80 debugfs = debugfs_create_dir("pkg_temp_thermal", NULL);
81
82 debugfs_create_u32("pkg_thres_interrupt", S_IRUGO, debugfs,
83 &pkg_interrupt_cnt);
84 debugfs_create_u32("pkg_thres_work", S_IRUGO, debugfs,
85 &pkg_work_cnt);
86 }
87
88 /*
89 * Protection:
90 *
91 * - cpu hotplug: Read serialized by cpu hotplug lock
92 * Write must hold pkg_temp_lock
93 *
94 * - Other callsites: Must hold pkg_temp_lock
95 */
pkg_temp_thermal_get_dev(unsigned int cpu)96 static struct zone_device *pkg_temp_thermal_get_dev(unsigned int cpu)
97 {
98 int id = topology_logical_die_id(cpu);
99
100 if (id >= 0 && id < max_id)
101 return zones[id];
102 return NULL;
103 }
104
105 /*
106 * tj-max is is interesting because threshold is set relative to this
107 * temperature.
108 */
get_tj_max(int cpu,u32 * tj_max)109 static int get_tj_max(int cpu, u32 *tj_max)
110 {
111 u32 eax, edx, val;
112 int err;
113
114 err = rdmsr_safe_on_cpu(cpu, MSR_IA32_TEMPERATURE_TARGET, &eax, &edx);
115 if (err)
116 return err;
117
118 val = (eax >> 16) & 0xff;
119 *tj_max = val * 1000;
120
121 return val ? 0 : -EINVAL;
122 }
123
sys_get_curr_temp(struct thermal_zone_device * tzd,int * temp)124 static int sys_get_curr_temp(struct thermal_zone_device *tzd, int *temp)
125 {
126 struct zone_device *zonedev = tzd->devdata;
127 u32 eax, edx;
128
129 rdmsr_on_cpu(zonedev->cpu, MSR_IA32_PACKAGE_THERM_STATUS,
130 &eax, &edx);
131 if (eax & 0x80000000) {
132 *temp = zonedev->tj_max - ((eax >> 16) & 0x7f) * 1000;
133 pr_debug("sys_get_curr_temp %d\n", *temp);
134 return 0;
135 }
136 return -EINVAL;
137 }
138
sys_get_trip_temp(struct thermal_zone_device * tzd,int trip,int * temp)139 static int sys_get_trip_temp(struct thermal_zone_device *tzd,
140 int trip, int *temp)
141 {
142 struct zone_device *zonedev = tzd->devdata;
143 unsigned long thres_reg_value;
144 u32 mask, shift, eax, edx;
145 int ret;
146
147 if (trip >= MAX_NUMBER_OF_TRIPS)
148 return -EINVAL;
149
150 if (trip) {
151 mask = THERM_MASK_THRESHOLD1;
152 shift = THERM_SHIFT_THRESHOLD1;
153 } else {
154 mask = THERM_MASK_THRESHOLD0;
155 shift = THERM_SHIFT_THRESHOLD0;
156 }
157
158 ret = rdmsr_on_cpu(zonedev->cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT,
159 &eax, &edx);
160 if (ret < 0)
161 return ret;
162
163 thres_reg_value = (eax & mask) >> shift;
164 if (thres_reg_value)
165 *temp = zonedev->tj_max - thres_reg_value * 1000;
166 else
167 *temp = THERMAL_TEMP_INVALID;
168 pr_debug("sys_get_trip_temp %d\n", *temp);
169
170 return 0;
171 }
172
173 static int
sys_set_trip_temp(struct thermal_zone_device * tzd,int trip,int temp)174 sys_set_trip_temp(struct thermal_zone_device *tzd, int trip, int temp)
175 {
176 struct zone_device *zonedev = tzd->devdata;
177 u32 l, h, mask, shift, intr;
178 int ret;
179
180 if (trip >= MAX_NUMBER_OF_TRIPS || temp >= zonedev->tj_max)
181 return -EINVAL;
182
183 ret = rdmsr_on_cpu(zonedev->cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT,
184 &l, &h);
185 if (ret < 0)
186 return ret;
187
188 if (trip) {
189 mask = THERM_MASK_THRESHOLD1;
190 shift = THERM_SHIFT_THRESHOLD1;
191 intr = THERM_INT_THRESHOLD1_ENABLE;
192 } else {
193 mask = THERM_MASK_THRESHOLD0;
194 shift = THERM_SHIFT_THRESHOLD0;
195 intr = THERM_INT_THRESHOLD0_ENABLE;
196 }
197 l &= ~mask;
198 /*
199 * When users space sets a trip temperature == 0, which is indication
200 * that, it is no longer interested in receiving notifications.
201 */
202 if (!temp) {
203 l &= ~intr;
204 } else {
205 l |= (zonedev->tj_max - temp)/1000 << shift;
206 l |= intr;
207 }
208
209 return wrmsr_on_cpu(zonedev->cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT,
210 l, h);
211 }
212
sys_get_trip_type(struct thermal_zone_device * thermal,int trip,enum thermal_trip_type * type)213 static int sys_get_trip_type(struct thermal_zone_device *thermal, int trip,
214 enum thermal_trip_type *type)
215 {
216 *type = THERMAL_TRIP_PASSIVE;
217 return 0;
218 }
219
220 /* Thermal zone callback registry */
221 static struct thermal_zone_device_ops tzone_ops = {
222 .get_temp = sys_get_curr_temp,
223 .get_trip_temp = sys_get_trip_temp,
224 .get_trip_type = sys_get_trip_type,
225 .set_trip_temp = sys_set_trip_temp,
226 };
227
pkg_thermal_rate_control(void)228 static bool pkg_thermal_rate_control(void)
229 {
230 return true;
231 }
232
233 /* Enable threshold interrupt on local package/cpu */
enable_pkg_thres_interrupt(void)234 static inline void enable_pkg_thres_interrupt(void)
235 {
236 u8 thres_0, thres_1;
237 u32 l, h;
238
239 rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
240 /* only enable/disable if it had valid threshold value */
241 thres_0 = (l & THERM_MASK_THRESHOLD0) >> THERM_SHIFT_THRESHOLD0;
242 thres_1 = (l & THERM_MASK_THRESHOLD1) >> THERM_SHIFT_THRESHOLD1;
243 if (thres_0)
244 l |= THERM_INT_THRESHOLD0_ENABLE;
245 if (thres_1)
246 l |= THERM_INT_THRESHOLD1_ENABLE;
247 wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
248 }
249
250 /* Disable threshold interrupt on local package/cpu */
disable_pkg_thres_interrupt(void)251 static inline void disable_pkg_thres_interrupt(void)
252 {
253 u32 l, h;
254
255 rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
256
257 l &= ~(THERM_INT_THRESHOLD0_ENABLE | THERM_INT_THRESHOLD1_ENABLE);
258 wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
259 }
260
pkg_temp_thermal_threshold_work_fn(struct work_struct * work)261 static void pkg_temp_thermal_threshold_work_fn(struct work_struct *work)
262 {
263 struct thermal_zone_device *tzone = NULL;
264 int cpu = smp_processor_id();
265 struct zone_device *zonedev;
266 u64 msr_val, wr_val;
267
268 mutex_lock(&thermal_zone_mutex);
269 raw_spin_lock_irq(&pkg_temp_lock);
270 ++pkg_work_cnt;
271
272 zonedev = pkg_temp_thermal_get_dev(cpu);
273 if (!zonedev) {
274 raw_spin_unlock_irq(&pkg_temp_lock);
275 mutex_unlock(&thermal_zone_mutex);
276 return;
277 }
278 zonedev->work_scheduled = false;
279
280 rdmsrl(MSR_IA32_PACKAGE_THERM_STATUS, msr_val);
281 wr_val = msr_val & ~(THERM_LOG_THRESHOLD0 | THERM_LOG_THRESHOLD1);
282 if (wr_val != msr_val) {
283 wrmsrl(MSR_IA32_PACKAGE_THERM_STATUS, wr_val);
284 tzone = zonedev->tzone;
285 }
286
287 enable_pkg_thres_interrupt();
288 raw_spin_unlock_irq(&pkg_temp_lock);
289
290 /*
291 * If tzone is not NULL, then thermal_zone_mutex will prevent the
292 * concurrent removal in the cpu offline callback.
293 */
294 if (tzone)
295 thermal_zone_device_update(tzone, THERMAL_EVENT_UNSPECIFIED);
296
297 mutex_unlock(&thermal_zone_mutex);
298 }
299
pkg_thermal_schedule_work(int cpu,struct delayed_work * work)300 static void pkg_thermal_schedule_work(int cpu, struct delayed_work *work)
301 {
302 unsigned long ms = msecs_to_jiffies(notify_delay_ms);
303
304 schedule_delayed_work_on(cpu, work, ms);
305 }
306
pkg_thermal_notify(u64 msr_val)307 static int pkg_thermal_notify(u64 msr_val)
308 {
309 int cpu = smp_processor_id();
310 struct zone_device *zonedev;
311 unsigned long flags;
312
313 raw_spin_lock_irqsave(&pkg_temp_lock, flags);
314 ++pkg_interrupt_cnt;
315
316 disable_pkg_thres_interrupt();
317
318 /* Work is per package, so scheduling it once is enough. */
319 zonedev = pkg_temp_thermal_get_dev(cpu);
320 if (zonedev && !zonedev->work_scheduled) {
321 zonedev->work_scheduled = true;
322 pkg_thermal_schedule_work(zonedev->cpu, &zonedev->work);
323 }
324
325 raw_spin_unlock_irqrestore(&pkg_temp_lock, flags);
326 return 0;
327 }
328
pkg_temp_thermal_device_add(unsigned int cpu)329 static int pkg_temp_thermal_device_add(unsigned int cpu)
330 {
331 int id = topology_logical_die_id(cpu);
332 u32 tj_max, eax, ebx, ecx, edx;
333 struct zone_device *zonedev;
334 int thres_count, err;
335
336 if (id >= max_id)
337 return -ENOMEM;
338
339 cpuid(6, &eax, &ebx, &ecx, &edx);
340 thres_count = ebx & 0x07;
341 if (!thres_count)
342 return -ENODEV;
343
344 thres_count = clamp_val(thres_count, 0, MAX_NUMBER_OF_TRIPS);
345
346 err = get_tj_max(cpu, &tj_max);
347 if (err)
348 return err;
349
350 zonedev = kzalloc(sizeof(*zonedev), GFP_KERNEL);
351 if (!zonedev)
352 return -ENOMEM;
353
354 INIT_DELAYED_WORK(&zonedev->work, pkg_temp_thermal_threshold_work_fn);
355 zonedev->cpu = cpu;
356 zonedev->tj_max = tj_max;
357 zonedev->tzone = thermal_zone_device_register("x86_pkg_temp",
358 thres_count,
359 (thres_count == MAX_NUMBER_OF_TRIPS) ? 0x03 : 0x01,
360 zonedev, &tzone_ops, &pkg_temp_tz_params, 0, 0);
361 if (IS_ERR(zonedev->tzone)) {
362 err = PTR_ERR(zonedev->tzone);
363 kfree(zonedev);
364 return err;
365 }
366 err = thermal_zone_device_enable(zonedev->tzone);
367 if (err) {
368 thermal_zone_device_unregister(zonedev->tzone);
369 kfree(zonedev);
370 return err;
371 }
372 /* Store MSR value for package thermal interrupt, to restore at exit */
373 rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, zonedev->msr_pkg_therm_low,
374 zonedev->msr_pkg_therm_high);
375
376 cpumask_set_cpu(cpu, &zonedev->cpumask);
377 raw_spin_lock_irq(&pkg_temp_lock);
378 zones[id] = zonedev;
379 raw_spin_unlock_irq(&pkg_temp_lock);
380 return 0;
381 }
382
pkg_thermal_cpu_offline(unsigned int cpu)383 static int pkg_thermal_cpu_offline(unsigned int cpu)
384 {
385 struct zone_device *zonedev = pkg_temp_thermal_get_dev(cpu);
386 bool lastcpu, was_target;
387 int target;
388
389 if (!zonedev)
390 return 0;
391
392 target = cpumask_any_but(&zonedev->cpumask, cpu);
393 cpumask_clear_cpu(cpu, &zonedev->cpumask);
394 lastcpu = target >= nr_cpu_ids;
395 /*
396 * Remove the sysfs files, if this is the last cpu in the package
397 * before doing further cleanups.
398 */
399 if (lastcpu) {
400 struct thermal_zone_device *tzone = zonedev->tzone;
401
402 /*
403 * We must protect against a work function calling
404 * thermal_zone_update, after/while unregister. We null out
405 * the pointer under the zone mutex, so the worker function
406 * won't try to call.
407 */
408 mutex_lock(&thermal_zone_mutex);
409 zonedev->tzone = NULL;
410 mutex_unlock(&thermal_zone_mutex);
411
412 thermal_zone_device_unregister(tzone);
413 }
414
415 /* Protect against work and interrupts */
416 raw_spin_lock_irq(&pkg_temp_lock);
417
418 /*
419 * Check whether this cpu was the current target and store the new
420 * one. When we drop the lock, then the interrupt notify function
421 * will see the new target.
422 */
423 was_target = zonedev->cpu == cpu;
424 zonedev->cpu = target;
425
426 /*
427 * If this is the last CPU in the package remove the package
428 * reference from the array and restore the interrupt MSR. When we
429 * drop the lock neither the interrupt notify function nor the
430 * worker will see the package anymore.
431 */
432 if (lastcpu) {
433 zones[topology_logical_die_id(cpu)] = NULL;
434 /* After this point nothing touches the MSR anymore. */
435 wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
436 zonedev->msr_pkg_therm_low, zonedev->msr_pkg_therm_high);
437 }
438
439 /*
440 * Check whether there is work scheduled and whether the work is
441 * targeted at the outgoing CPU.
442 */
443 if (zonedev->work_scheduled && was_target) {
444 /*
445 * To cancel the work we need to drop the lock, otherwise
446 * we might deadlock if the work needs to be flushed.
447 */
448 raw_spin_unlock_irq(&pkg_temp_lock);
449 cancel_delayed_work_sync(&zonedev->work);
450 raw_spin_lock_irq(&pkg_temp_lock);
451 /*
452 * If this is not the last cpu in the package and the work
453 * did not run after we dropped the lock above, then we
454 * need to reschedule the work, otherwise the interrupt
455 * stays disabled forever.
456 */
457 if (!lastcpu && zonedev->work_scheduled)
458 pkg_thermal_schedule_work(target, &zonedev->work);
459 }
460
461 raw_spin_unlock_irq(&pkg_temp_lock);
462
463 /* Final cleanup if this is the last cpu */
464 if (lastcpu)
465 kfree(zonedev);
466 return 0;
467 }
468
pkg_thermal_cpu_online(unsigned int cpu)469 static int pkg_thermal_cpu_online(unsigned int cpu)
470 {
471 struct zone_device *zonedev = pkg_temp_thermal_get_dev(cpu);
472 struct cpuinfo_x86 *c = &cpu_data(cpu);
473
474 /* Paranoia check */
475 if (!cpu_has(c, X86_FEATURE_DTHERM) || !cpu_has(c, X86_FEATURE_PTS))
476 return -ENODEV;
477
478 /* If the package exists, nothing to do */
479 if (zonedev) {
480 cpumask_set_cpu(cpu, &zonedev->cpumask);
481 return 0;
482 }
483 return pkg_temp_thermal_device_add(cpu);
484 }
485
486 static const struct x86_cpu_id __initconst pkg_temp_thermal_ids[] = {
487 X86_MATCH_VENDOR_FEATURE(INTEL, X86_FEATURE_PTS, NULL),
488 {}
489 };
490 MODULE_DEVICE_TABLE(x86cpu, pkg_temp_thermal_ids);
491
pkg_temp_thermal_init(void)492 static int __init pkg_temp_thermal_init(void)
493 {
494 int ret;
495
496 if (!x86_match_cpu(pkg_temp_thermal_ids))
497 return -ENODEV;
498
499 max_id = topology_max_packages() * topology_max_die_per_package();
500 zones = kcalloc(max_id, sizeof(struct zone_device *),
501 GFP_KERNEL);
502 if (!zones)
503 return -ENOMEM;
504
505 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "thermal/x86_pkg:online",
506 pkg_thermal_cpu_online, pkg_thermal_cpu_offline);
507 if (ret < 0)
508 goto err;
509
510 /* Store the state for module exit */
511 pkg_thermal_hp_state = ret;
512
513 platform_thermal_package_notify = pkg_thermal_notify;
514 platform_thermal_package_rate_control = pkg_thermal_rate_control;
515
516 /* Don't care if it fails */
517 pkg_temp_debugfs_init();
518 return 0;
519
520 err:
521 kfree(zones);
522 return ret;
523 }
module_init(pkg_temp_thermal_init)524 module_init(pkg_temp_thermal_init)
525
526 static void __exit pkg_temp_thermal_exit(void)
527 {
528 platform_thermal_package_notify = NULL;
529 platform_thermal_package_rate_control = NULL;
530
531 cpuhp_remove_state(pkg_thermal_hp_state);
532 debugfs_remove_recursive(debugfs);
533 kfree(zones);
534 }
535 module_exit(pkg_temp_thermal_exit)
536
537 MODULE_DESCRIPTION("X86 PKG TEMP Thermal Driver");
538 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
539 MODULE_LICENSE("GPL v2");
540