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
21 #include <asm/cpu_device_id.h>
22
23 #include "thermal_interrupt.h"
24
25 /*
26 * Rate control delay: Idea is to introduce denounce effect
27 * This should be long enough to avoid reduce events, when
28 * threshold is set to a temperature, which is constantly
29 * violated, but at the short enough to take any action.
30 * The action can be remove threshold or change it to next
31 * interesting setting. Based on experiments, in around
32 * every 5 seconds under load will give us a significant
33 * temperature change.
34 */
35 #define PKG_TEMP_THERMAL_NOTIFY_DELAY 5000
36 static int notify_delay_ms = PKG_TEMP_THERMAL_NOTIFY_DELAY;
37 module_param(notify_delay_ms, int, 0644);
38 MODULE_PARM_DESC(notify_delay_ms,
39 "User space notification delay in milli seconds.");
40
41 /* Number of trip points in thermal zone. Currently it can't
42 * be more than 2. MSR can allow setting and getting notifications
43 * for only 2 thresholds. This define enforces this, if there
44 * is some wrong values returned by cpuid for number of thresholds.
45 */
46 #define MAX_NUMBER_OF_TRIPS 2
47
48 struct zone_device {
49 int cpu;
50 bool work_scheduled;
51 u32 tj_max;
52 u32 msr_pkg_therm_low;
53 u32 msr_pkg_therm_high;
54 struct delayed_work work;
55 struct thermal_zone_device *tzone;
56 struct cpumask cpumask;
57 };
58
59 static struct thermal_zone_params pkg_temp_tz_params = {
60 .no_hwmon = true,
61 };
62
63 /* Keep track of how many zone pointers we allocated in init() */
64 static int max_id __read_mostly;
65 /* Array of zone pointers */
66 static struct zone_device **zones;
67 /* Serializes interrupt notification, work and hotplug */
68 static DEFINE_RAW_SPINLOCK(pkg_temp_lock);
69 /* Protects zone operation in the work function against hotplug removal */
70 static DEFINE_MUTEX(thermal_zone_mutex);
71
72 /* The dynamically assigned cpu hotplug state for module_exit() */
73 static enum cpuhp_state pkg_thermal_hp_state __read_mostly;
74
75 /* Debug counters to show using debugfs */
76 static struct dentry *debugfs;
77 static unsigned int pkg_interrupt_cnt;
78 static unsigned int pkg_work_cnt;
79
pkg_temp_debugfs_init(void)80 static void pkg_temp_debugfs_init(void)
81 {
82 debugfs = debugfs_create_dir("pkg_temp_thermal", NULL);
83
84 debugfs_create_u32("pkg_thres_interrupt", S_IRUGO, debugfs,
85 &pkg_interrupt_cnt);
86 debugfs_create_u32("pkg_thres_work", S_IRUGO, debugfs,
87 &pkg_work_cnt);
88 }
89
90 /*
91 * Protection:
92 *
93 * - cpu hotplug: Read serialized by cpu hotplug lock
94 * Write must hold pkg_temp_lock
95 *
96 * - Other callsites: Must hold pkg_temp_lock
97 */
pkg_temp_thermal_get_dev(unsigned int cpu)98 static struct zone_device *pkg_temp_thermal_get_dev(unsigned int cpu)
99 {
100 int id = topology_logical_die_id(cpu);
101
102 if (id >= 0 && id < max_id)
103 return zones[id];
104 return NULL;
105 }
106
107 /*
108 * tj-max is is interesting because threshold is set relative to this
109 * temperature.
110 */
get_tj_max(int cpu,u32 * tj_max)111 static int get_tj_max(int cpu, u32 *tj_max)
112 {
113 u32 eax, edx, val;
114 int err;
115
116 err = rdmsr_safe_on_cpu(cpu, MSR_IA32_TEMPERATURE_TARGET, &eax, &edx);
117 if (err)
118 return err;
119
120 val = (eax >> 16) & 0xff;
121 *tj_max = val * 1000;
122
123 return val ? 0 : -EINVAL;
124 }
125
sys_get_curr_temp(struct thermal_zone_device * tzd,int * temp)126 static int sys_get_curr_temp(struct thermal_zone_device *tzd, int *temp)
127 {
128 struct zone_device *zonedev = tzd->devdata;
129 u32 eax, edx;
130
131 rdmsr_on_cpu(zonedev->cpu, MSR_IA32_PACKAGE_THERM_STATUS,
132 &eax, &edx);
133 if (eax & 0x80000000) {
134 *temp = zonedev->tj_max - ((eax >> 16) & 0x7f) * 1000;
135 pr_debug("sys_get_curr_temp %d\n", *temp);
136 return 0;
137 }
138 return -EINVAL;
139 }
140
sys_get_trip_temp(struct thermal_zone_device * tzd,int trip,int * temp)141 static int sys_get_trip_temp(struct thermal_zone_device *tzd,
142 int trip, int *temp)
143 {
144 struct zone_device *zonedev = tzd->devdata;
145 unsigned long thres_reg_value;
146 u32 mask, shift, eax, edx;
147 int ret;
148
149 if (trip >= MAX_NUMBER_OF_TRIPS)
150 return -EINVAL;
151
152 if (trip) {
153 mask = THERM_MASK_THRESHOLD1;
154 shift = THERM_SHIFT_THRESHOLD1;
155 } else {
156 mask = THERM_MASK_THRESHOLD0;
157 shift = THERM_SHIFT_THRESHOLD0;
158 }
159
160 ret = rdmsr_on_cpu(zonedev->cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT,
161 &eax, &edx);
162 if (ret < 0)
163 return ret;
164
165 thres_reg_value = (eax & mask) >> shift;
166 if (thres_reg_value)
167 *temp = zonedev->tj_max - thres_reg_value * 1000;
168 else
169 *temp = 0;
170 pr_debug("sys_get_trip_temp %d\n", *temp);
171
172 return 0;
173 }
174
175 static int
sys_set_trip_temp(struct thermal_zone_device * tzd,int trip,int temp)176 sys_set_trip_temp(struct thermal_zone_device *tzd, int trip, int temp)
177 {
178 struct zone_device *zonedev = tzd->devdata;
179 u32 l, h, mask, shift, intr;
180 int ret;
181
182 if (trip >= MAX_NUMBER_OF_TRIPS || temp >= zonedev->tj_max)
183 return -EINVAL;
184
185 ret = rdmsr_on_cpu(zonedev->cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT,
186 &l, &h);
187 if (ret < 0)
188 return ret;
189
190 if (trip) {
191 mask = THERM_MASK_THRESHOLD1;
192 shift = THERM_SHIFT_THRESHOLD1;
193 intr = THERM_INT_THRESHOLD1_ENABLE;
194 } else {
195 mask = THERM_MASK_THRESHOLD0;
196 shift = THERM_SHIFT_THRESHOLD0;
197 intr = THERM_INT_THRESHOLD0_ENABLE;
198 }
199 l &= ~mask;
200 /*
201 * When users space sets a trip temperature == 0, which is indication
202 * that, it is no longer interested in receiving notifications.
203 */
204 if (!temp) {
205 l &= ~intr;
206 } else {
207 l |= (zonedev->tj_max - temp)/1000 << shift;
208 l |= intr;
209 }
210
211 return wrmsr_on_cpu(zonedev->cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT,
212 l, h);
213 }
214
sys_get_trip_type(struct thermal_zone_device * thermal,int trip,enum thermal_trip_type * type)215 static int sys_get_trip_type(struct thermal_zone_device *thermal, int trip,
216 enum thermal_trip_type *type)
217 {
218 *type = THERMAL_TRIP_PASSIVE;
219 return 0;
220 }
221
222 /* Thermal zone callback registry */
223 static struct thermal_zone_device_ops tzone_ops = {
224 .get_temp = sys_get_curr_temp,
225 .get_trip_temp = sys_get_trip_temp,
226 .get_trip_type = sys_get_trip_type,
227 .set_trip_temp = sys_set_trip_temp,
228 };
229
pkg_thermal_rate_control(void)230 static bool pkg_thermal_rate_control(void)
231 {
232 return true;
233 }
234
235 /* Enable threshold interrupt on local package/cpu */
enable_pkg_thres_interrupt(void)236 static inline void enable_pkg_thres_interrupt(void)
237 {
238 u8 thres_0, thres_1;
239 u32 l, h;
240
241 rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
242 /* only enable/disable if it had valid threshold value */
243 thres_0 = (l & THERM_MASK_THRESHOLD0) >> THERM_SHIFT_THRESHOLD0;
244 thres_1 = (l & THERM_MASK_THRESHOLD1) >> THERM_SHIFT_THRESHOLD1;
245 if (thres_0)
246 l |= THERM_INT_THRESHOLD0_ENABLE;
247 if (thres_1)
248 l |= THERM_INT_THRESHOLD1_ENABLE;
249 wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
250 }
251
252 /* Disable threshold interrupt on local package/cpu */
disable_pkg_thres_interrupt(void)253 static inline void disable_pkg_thres_interrupt(void)
254 {
255 u32 l, h;
256
257 rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
258
259 l &= ~(THERM_INT_THRESHOLD0_ENABLE | THERM_INT_THRESHOLD1_ENABLE);
260 wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
261 }
262
pkg_temp_thermal_threshold_work_fn(struct work_struct * work)263 static void pkg_temp_thermal_threshold_work_fn(struct work_struct *work)
264 {
265 struct thermal_zone_device *tzone = NULL;
266 int cpu = smp_processor_id();
267 struct zone_device *zonedev;
268 u64 msr_val, wr_val;
269
270 mutex_lock(&thermal_zone_mutex);
271 raw_spin_lock_irq(&pkg_temp_lock);
272 ++pkg_work_cnt;
273
274 zonedev = pkg_temp_thermal_get_dev(cpu);
275 if (!zonedev) {
276 raw_spin_unlock_irq(&pkg_temp_lock);
277 mutex_unlock(&thermal_zone_mutex);
278 return;
279 }
280 zonedev->work_scheduled = false;
281
282 rdmsrl(MSR_IA32_PACKAGE_THERM_STATUS, msr_val);
283 wr_val = msr_val & ~(THERM_LOG_THRESHOLD0 | THERM_LOG_THRESHOLD1);
284 if (wr_val != msr_val) {
285 wrmsrl(MSR_IA32_PACKAGE_THERM_STATUS, wr_val);
286 tzone = zonedev->tzone;
287 }
288
289 enable_pkg_thres_interrupt();
290 raw_spin_unlock_irq(&pkg_temp_lock);
291
292 /*
293 * If tzone is not NULL, then thermal_zone_mutex will prevent the
294 * concurrent removal in the cpu offline callback.
295 */
296 if (tzone)
297 thermal_zone_device_update(tzone, THERMAL_EVENT_UNSPECIFIED);
298
299 mutex_unlock(&thermal_zone_mutex);
300 }
301
pkg_thermal_schedule_work(int cpu,struct delayed_work * work)302 static void pkg_thermal_schedule_work(int cpu, struct delayed_work *work)
303 {
304 unsigned long ms = msecs_to_jiffies(notify_delay_ms);
305
306 schedule_delayed_work_on(cpu, work, ms);
307 }
308
pkg_thermal_notify(u64 msr_val)309 static int pkg_thermal_notify(u64 msr_val)
310 {
311 int cpu = smp_processor_id();
312 struct zone_device *zonedev;
313 unsigned long flags;
314
315 raw_spin_lock_irqsave(&pkg_temp_lock, flags);
316 ++pkg_interrupt_cnt;
317
318 disable_pkg_thres_interrupt();
319
320 /* Work is per package, so scheduling it once is enough. */
321 zonedev = pkg_temp_thermal_get_dev(cpu);
322 if (zonedev && !zonedev->work_scheduled) {
323 zonedev->work_scheduled = true;
324 pkg_thermal_schedule_work(zonedev->cpu, &zonedev->work);
325 }
326
327 raw_spin_unlock_irqrestore(&pkg_temp_lock, flags);
328 return 0;
329 }
330
pkg_temp_thermal_device_add(unsigned int cpu)331 static int pkg_temp_thermal_device_add(unsigned int cpu)
332 {
333 int id = topology_logical_die_id(cpu);
334 u32 tj_max, eax, ebx, ecx, edx;
335 struct zone_device *zonedev;
336 int thres_count, err;
337
338 if (id >= max_id)
339 return -ENOMEM;
340
341 cpuid(6, &eax, &ebx, &ecx, &edx);
342 thres_count = ebx & 0x07;
343 if (!thres_count)
344 return -ENODEV;
345
346 thres_count = clamp_val(thres_count, 0, MAX_NUMBER_OF_TRIPS);
347
348 err = get_tj_max(cpu, &tj_max);
349 if (err)
350 return err;
351
352 zonedev = kzalloc(sizeof(*zonedev), GFP_KERNEL);
353 if (!zonedev)
354 return -ENOMEM;
355
356 INIT_DELAYED_WORK(&zonedev->work, pkg_temp_thermal_threshold_work_fn);
357 zonedev->cpu = cpu;
358 zonedev->tj_max = tj_max;
359 zonedev->tzone = thermal_zone_device_register("x86_pkg_temp",
360 thres_count,
361 (thres_count == MAX_NUMBER_OF_TRIPS) ? 0x03 : 0x01,
362 zonedev, &tzone_ops, &pkg_temp_tz_params, 0, 0);
363 if (IS_ERR(zonedev->tzone)) {
364 err = PTR_ERR(zonedev->tzone);
365 kfree(zonedev);
366 return err;
367 }
368 err = thermal_zone_device_enable(zonedev->tzone);
369 if (err) {
370 thermal_zone_device_unregister(zonedev->tzone);
371 kfree(zonedev);
372 return err;
373 }
374 /* Store MSR value for package thermal interrupt, to restore at exit */
375 rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, zonedev->msr_pkg_therm_low,
376 zonedev->msr_pkg_therm_high);
377
378 cpumask_set_cpu(cpu, &zonedev->cpumask);
379 raw_spin_lock_irq(&pkg_temp_lock);
380 zones[id] = zonedev;
381 raw_spin_unlock_irq(&pkg_temp_lock);
382 return 0;
383 }
384
pkg_thermal_cpu_offline(unsigned int cpu)385 static int pkg_thermal_cpu_offline(unsigned int cpu)
386 {
387 struct zone_device *zonedev = pkg_temp_thermal_get_dev(cpu);
388 bool lastcpu, was_target;
389 int target;
390
391 if (!zonedev)
392 return 0;
393
394 target = cpumask_any_but(&zonedev->cpumask, cpu);
395 cpumask_clear_cpu(cpu, &zonedev->cpumask);
396 lastcpu = target >= nr_cpu_ids;
397 /*
398 * Remove the sysfs files, if this is the last cpu in the package
399 * before doing further cleanups.
400 */
401 if (lastcpu) {
402 struct thermal_zone_device *tzone = zonedev->tzone;
403
404 /*
405 * We must protect against a work function calling
406 * thermal_zone_update, after/while unregister. We null out
407 * the pointer under the zone mutex, so the worker function
408 * won't try to call.
409 */
410 mutex_lock(&thermal_zone_mutex);
411 zonedev->tzone = NULL;
412 mutex_unlock(&thermal_zone_mutex);
413
414 thermal_zone_device_unregister(tzone);
415 }
416
417 /* Protect against work and interrupts */
418 raw_spin_lock_irq(&pkg_temp_lock);
419
420 /*
421 * Check whether this cpu was the current target and store the new
422 * one. When we drop the lock, then the interrupt notify function
423 * will see the new target.
424 */
425 was_target = zonedev->cpu == cpu;
426 zonedev->cpu = target;
427
428 /*
429 * If this is the last CPU in the package remove the package
430 * reference from the array and restore the interrupt MSR. When we
431 * drop the lock neither the interrupt notify function nor the
432 * worker will see the package anymore.
433 */
434 if (lastcpu) {
435 zones[topology_logical_die_id(cpu)] = NULL;
436 /* After this point nothing touches the MSR anymore. */
437 wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
438 zonedev->msr_pkg_therm_low, zonedev->msr_pkg_therm_high);
439 }
440
441 /*
442 * Check whether there is work scheduled and whether the work is
443 * targeted at the outgoing CPU.
444 */
445 if (zonedev->work_scheduled && was_target) {
446 /*
447 * To cancel the work we need to drop the lock, otherwise
448 * we might deadlock if the work needs to be flushed.
449 */
450 raw_spin_unlock_irq(&pkg_temp_lock);
451 cancel_delayed_work_sync(&zonedev->work);
452 raw_spin_lock_irq(&pkg_temp_lock);
453 /*
454 * If this is not the last cpu in the package and the work
455 * did not run after we dropped the lock above, then we
456 * need to reschedule the work, otherwise the interrupt
457 * stays disabled forever.
458 */
459 if (!lastcpu && zonedev->work_scheduled)
460 pkg_thermal_schedule_work(target, &zonedev->work);
461 }
462
463 raw_spin_unlock_irq(&pkg_temp_lock);
464
465 /* Final cleanup if this is the last cpu */
466 if (lastcpu)
467 kfree(zonedev);
468 return 0;
469 }
470
pkg_thermal_cpu_online(unsigned int cpu)471 static int pkg_thermal_cpu_online(unsigned int cpu)
472 {
473 struct zone_device *zonedev = pkg_temp_thermal_get_dev(cpu);
474 struct cpuinfo_x86 *c = &cpu_data(cpu);
475
476 /* Paranoia check */
477 if (!cpu_has(c, X86_FEATURE_DTHERM) || !cpu_has(c, X86_FEATURE_PTS))
478 return -ENODEV;
479
480 /* If the package exists, nothing to do */
481 if (zonedev) {
482 cpumask_set_cpu(cpu, &zonedev->cpumask);
483 return 0;
484 }
485 return pkg_temp_thermal_device_add(cpu);
486 }
487
488 static const struct x86_cpu_id __initconst pkg_temp_thermal_ids[] = {
489 X86_MATCH_VENDOR_FEATURE(INTEL, X86_FEATURE_PTS, NULL),
490 {}
491 };
492 MODULE_DEVICE_TABLE(x86cpu, pkg_temp_thermal_ids);
493
pkg_temp_thermal_init(void)494 static int __init pkg_temp_thermal_init(void)
495 {
496 int ret;
497
498 if (!x86_match_cpu(pkg_temp_thermal_ids))
499 return -ENODEV;
500
501 max_id = topology_max_packages() * topology_max_die_per_package();
502 zones = kcalloc(max_id, sizeof(struct zone_device *),
503 GFP_KERNEL);
504 if (!zones)
505 return -ENOMEM;
506
507 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "thermal/x86_pkg:online",
508 pkg_thermal_cpu_online, pkg_thermal_cpu_offline);
509 if (ret < 0)
510 goto err;
511
512 /* Store the state for module exit */
513 pkg_thermal_hp_state = ret;
514
515 platform_thermal_package_notify = pkg_thermal_notify;
516 platform_thermal_package_rate_control = pkg_thermal_rate_control;
517
518 /* Don't care if it fails */
519 pkg_temp_debugfs_init();
520 return 0;
521
522 err:
523 kfree(zones);
524 return ret;
525 }
module_init(pkg_temp_thermal_init)526 module_init(pkg_temp_thermal_init)
527
528 static void __exit pkg_temp_thermal_exit(void)
529 {
530 platform_thermal_package_notify = NULL;
531 platform_thermal_package_rate_control = NULL;
532
533 cpuhp_remove_state(pkg_thermal_hp_state);
534 debugfs_remove_recursive(debugfs);
535 kfree(zones);
536 }
537 module_exit(pkg_temp_thermal_exit)
538
539 MODULE_DESCRIPTION("X86 PKG TEMP Thermal Driver");
540 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
541 MODULE_LICENSE("GPL v2");
542