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