1 // SPDX-License-Identifier: GPL-2.0-only
3 * coretemp.c - Linux kernel module for hardware monitoring
7 * Inspired from many hwmon drivers
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/slab.h>
15 #include <linux/jiffies.h>
16 #include <linux/hwmon.h>
17 #include <linux/sysfs.h>
18 #include <linux/hwmon-sysfs.h>
19 #include <linux/err.h>
20 #include <linux/mutex.h>
21 #include <linux/list.h>
22 #include <linux/platform_device.h>
23 #include <linux/cpu.h>
24 #include <linux/smp.h>
25 #include <linux/moduleparam.h>
26 #include <linux/pci.h>
28 #include <asm/processor.h>
29 #include <asm/cpu_device_id.h>
30 #include <linux/sched/isolation.h>
32 #define DRVNAME "coretemp"
35 * force_tjmax only matters when TjMax can't be read from the CPU itself.
36 * When set, it replaces the driver's suboptimal heuristic.
38 static int force_tjmax;
39 module_param_named(tjmax, force_tjmax, int, 0444);
40 MODULE_PARM_DESC(tjmax, "TjMax value in degrees Celsius");
42 #define PKG_SYSFS_ATTR_NO 1 /* Sysfs attribute for package temp */
43 #define BASE_SYSFS_ATTR_NO 2 /* Sysfs Base attr no for coretemp */
44 #define NUM_REAL_CORES 128 /* Number of Real cores per cpu */
45 #define CORETEMP_NAME_LENGTH 19 /* String Length of attrs */
46 #define MAX_CORE_ATTRS 4 /* Maximum no of basic attrs */
47 #define TOTAL_ATTRS (MAX_CORE_ATTRS + 1)
48 #define MAX_CORE_DATA (NUM_REAL_CORES + BASE_SYSFS_ATTR_NO)
51 #define for_each_sibling(i, cpu) \
52 for_each_cpu(i, topology_sibling_cpumask(cpu))
54 #define for_each_sibling(i, cpu) for (i = 0; false; )
58 * Per-Core Temperature Data
59 * @tjmax: The static tjmax value when tjmax cannot be retrieved from
60 * IA32_TEMPERATURE_TARGET MSR.
61 * @last_updated: The time when the current temperature value was updated
62 * earlier (in jiffies).
63 * @cpu_core_id: The CPU Core from which temperature values should be read
64 * This value is passed as "id" field to rdmsr/wrmsr functions.
65 * @status_reg: One of IA32_THERM_STATUS or IA32_PACKAGE_THERM_STATUS,
66 * from where the temperature values should be read.
67 * @attr_size: Total number of pre-core attrs displayed in the sysfs.
68 * @is_pkg_data: If this is 1, the temp_data holds pkgtemp data.
69 * Otherwise, temp_data holds coretemp data.
74 unsigned long last_updated;
80 struct sensor_device_attribute sd_attrs[TOTAL_ATTRS];
81 char attr_name[TOTAL_ATTRS][CORETEMP_NAME_LENGTH];
82 struct attribute *attrs[TOTAL_ATTRS + 1];
83 struct attribute_group attr_group;
84 struct mutex update_lock;
87 /* Platform Data per Physical CPU */
88 struct platform_data {
89 struct device *hwmon_dev;
91 u16 cpu_map[NUM_REAL_CORES];
93 struct cpumask cpumask;
94 struct temp_data *core_data[MAX_CORE_DATA];
95 struct device_attribute name_attr;
103 static const struct tjmax_pci tjmax_pci_table[] = {
104 { 0x0708, 110000 }, /* CE41x0 (Sodaville ) */
105 { 0x0c72, 102000 }, /* Atom S1240 (Centerton) */
106 { 0x0c73, 95000 }, /* Atom S1220 (Centerton) */
107 { 0x0c75, 95000 }, /* Atom S1260 (Centerton) */
115 static const struct tjmax tjmax_table[] = {
116 { "CPU 230", 100000 }, /* Model 0x1c, stepping 2 */
117 { "CPU 330", 125000 }, /* Model 0x1c, stepping 2 */
128 static const struct tjmax_model tjmax_model_table[] = {
129 { 0x1c, 10, 100000 }, /* D4xx, K4xx, N4xx, D5xx, K5xx, N5xx */
130 { 0x1c, ANY, 90000 }, /* Z5xx, N2xx, possibly others
131 * Note: Also matches 230 and 330,
132 * which are covered by tjmax_table
134 { 0x26, ANY, 90000 }, /* Atom Tunnel Creek (Exx), Lincroft (Z6xx)
135 * Note: TjMax for E6xxT is 110C, but CPU type
136 * is undetectable by software
138 { 0x27, ANY, 90000 }, /* Atom Medfield (Z2460) */
139 { 0x35, ANY, 90000 }, /* Atom Clover Trail/Cloverview (Z27x0) */
140 { 0x36, ANY, 100000 }, /* Atom Cedar Trail/Cedarview (N2xxx, D2xxx)
141 * Also matches S12x0 (stepping 9), covered by
146 static int adjust_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *dev)
148 /* The 100C is default for both mobile and non mobile CPUs */
151 int tjmax_ee = 85000;
156 u16 devfn = PCI_DEVFN(0, 0);
157 struct pci_dev *host_bridge = pci_get_domain_bus_and_slot(0, 0, devfn);
160 * Explicit tjmax table entries override heuristics.
161 * First try PCI host bridge IDs, followed by model ID strings
162 * and model/stepping information.
164 if (host_bridge && host_bridge->vendor == PCI_VENDOR_ID_INTEL) {
165 for (i = 0; i < ARRAY_SIZE(tjmax_pci_table); i++) {
166 if (host_bridge->device == tjmax_pci_table[i].device) {
167 pci_dev_put(host_bridge);
168 return tjmax_pci_table[i].tjmax;
172 pci_dev_put(host_bridge);
174 for (i = 0; i < ARRAY_SIZE(tjmax_table); i++) {
175 if (strstr(c->x86_model_id, tjmax_table[i].id))
176 return tjmax_table[i].tjmax;
179 for (i = 0; i < ARRAY_SIZE(tjmax_model_table); i++) {
180 const struct tjmax_model *tm = &tjmax_model_table[i];
181 if (c->x86_model == tm->model &&
182 (tm->mask == ANY || c->x86_stepping == tm->mask))
186 /* Early chips have no MSR for TjMax */
188 if (c->x86_model == 0xf && c->x86_stepping < 4)
191 if (c->x86_model > 0xe && usemsr_ee) {
195 * Now we can detect the mobile CPU using Intel provided table
196 * http://softwarecommunity.intel.com/Wiki/Mobility/720.htm
197 * For Core2 cores, check MSR 0x17, bit 28 1 = Mobile CPU
199 err = rdmsr_safe_on_cpu(id, 0x17, &eax, &edx);
202 "Unable to access MSR 0x17, assuming desktop"
205 } else if (c->x86_model < 0x17 && !(eax & 0x10000000)) {
207 * Trust bit 28 up to Penryn, I could not find any
208 * documentation on that; if you happen to know
209 * someone at Intel please ask
213 /* Platform ID bits 52:50 (EDX starts at bit 32) */
214 platform_id = (edx >> 18) & 0x7;
217 * Mobile Penryn CPU seems to be platform ID 7 or 5
220 if (c->x86_model == 0x17 &&
221 (platform_id == 5 || platform_id == 7)) {
223 * If MSR EE bit is set, set it to 90 degrees C,
224 * otherwise 105 degrees C
233 err = rdmsr_safe_on_cpu(id, 0xee, &eax, &edx);
236 "Unable to access MSR 0xEE, for Tjmax, left"
238 } else if (eax & 0x40000000) {
241 } else if (tjmax == 100000) {
243 * If we don't use msr EE it means we are desktop CPU
244 * (with exeception of Atom)
246 dev_warn(dev, "Using relative temperature scale!\n");
252 static bool cpu_has_tjmax(struct cpuinfo_x86 *c)
254 u8 model = c->x86_model;
256 return model > 0xe &&
264 static int get_tjmax(struct temp_data *tdata, struct device *dev)
266 struct cpuinfo_x86 *c = &cpu_data(tdata->cpu);
271 /* use static tjmax once it is set */
276 * A new feature of current Intel(R) processors, the
277 * IA32_TEMPERATURE_TARGET contains the TjMax value
279 err = rdmsr_safe_on_cpu(tdata->cpu, MSR_IA32_TEMPERATURE_TARGET, &eax, &edx);
281 if (cpu_has_tjmax(c))
282 dev_warn(dev, "Unable to read TjMax from CPU %u\n", tdata->cpu);
284 val = (eax >> 16) & 0xff;
286 * If the TjMax is not plausible, an assumption
290 dev_dbg(dev, "TjMax is %d degrees C\n", val);
296 dev_notice(dev, "TjMax forced to %d degrees C by user\n",
298 tdata->tjmax = force_tjmax * 1000;
301 * An assumption is made for early CPUs and unreadable MSR.
302 * NOTE: the calculated value may not be correct.
304 tdata->tjmax = adjust_tjmax(c, tdata->cpu, dev);
309 static int get_ttarget(struct temp_data *tdata, struct device *dev)
312 int tjmax, ttarget_offset, ret;
315 * ttarget is valid only if tjmax can be retrieved from
316 * MSR_IA32_TEMPERATURE_TARGET
321 ret = rdmsr_safe_on_cpu(tdata->cpu, MSR_IA32_TEMPERATURE_TARGET, &eax, &edx);
325 tjmax = (eax >> 16) & 0xff;
327 /* Read the still undocumented bits 8:15 of IA32_TEMPERATURE_TARGET. */
328 ttarget_offset = (eax >> 8) & 0xff;
330 return (tjmax - ttarget_offset) * 1000;
333 /* Keep track of how many zone pointers we allocated in init() */
334 static int max_zones __read_mostly;
335 /* Array of zone pointers. Serialized by cpu hotplug lock */
336 static struct platform_device **zone_devices;
338 static ssize_t show_label(struct device *dev,
339 struct device_attribute *devattr, char *buf)
341 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
342 struct platform_data *pdata = dev_get_drvdata(dev);
343 struct temp_data *tdata = pdata->core_data[attr->index];
345 if (tdata->is_pkg_data)
346 return sprintf(buf, "Package id %u\n", pdata->pkg_id);
348 return sprintf(buf, "Core %u\n", tdata->cpu_core_id);
351 static ssize_t show_crit_alarm(struct device *dev,
352 struct device_attribute *devattr, char *buf)
355 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
356 struct platform_data *pdata = dev_get_drvdata(dev);
357 struct temp_data *tdata = pdata->core_data[attr->index];
359 mutex_lock(&tdata->update_lock);
360 rdmsr_on_cpu(tdata->cpu, tdata->status_reg, &eax, &edx);
361 mutex_unlock(&tdata->update_lock);
363 return sprintf(buf, "%d\n", (eax >> 5) & 1);
366 static ssize_t show_tjmax(struct device *dev,
367 struct device_attribute *devattr, char *buf)
369 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
370 struct platform_data *pdata = dev_get_drvdata(dev);
371 struct temp_data *tdata = pdata->core_data[attr->index];
374 mutex_lock(&tdata->update_lock);
375 tjmax = get_tjmax(tdata, dev);
376 mutex_unlock(&tdata->update_lock);
378 return sprintf(buf, "%d\n", tjmax);
381 static ssize_t show_ttarget(struct device *dev,
382 struct device_attribute *devattr, char *buf)
384 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
385 struct platform_data *pdata = dev_get_drvdata(dev);
386 struct temp_data *tdata = pdata->core_data[attr->index];
389 mutex_lock(&tdata->update_lock);
390 ttarget = get_ttarget(tdata, dev);
391 mutex_unlock(&tdata->update_lock);
395 return sprintf(buf, "%d\n", ttarget);
398 static ssize_t show_temp(struct device *dev,
399 struct device_attribute *devattr, char *buf)
402 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
403 struct platform_data *pdata = dev_get_drvdata(dev);
404 struct temp_data *tdata = pdata->core_data[attr->index];
407 mutex_lock(&tdata->update_lock);
409 tjmax = get_tjmax(tdata, dev);
410 /* Check whether the time interval has elapsed */
411 if (time_after(jiffies, tdata->last_updated + HZ)) {
412 rdmsr_on_cpu(tdata->cpu, tdata->status_reg, &eax, &edx);
414 * Ignore the valid bit. In all observed cases the register
415 * value is either low or zero if the valid bit is 0.
416 * Return it instead of reporting an error which doesn't
417 * really help at all.
419 tdata->temp = tjmax - ((eax >> 16) & 0x7f) * 1000;
420 tdata->last_updated = jiffies;
423 mutex_unlock(&tdata->update_lock);
424 return sprintf(buf, "%d\n", tdata->temp);
427 static int create_core_attrs(struct temp_data *tdata, struct device *dev,
431 static ssize_t (*const rd_ptr[TOTAL_ATTRS]) (struct device *dev,
432 struct device_attribute *devattr, char *buf) = {
433 show_label, show_crit_alarm, show_temp, show_tjmax,
435 static const char *const suffixes[TOTAL_ATTRS] = {
436 "label", "crit_alarm", "input", "crit", "max"
439 for (i = 0; i < tdata->attr_size; i++) {
440 snprintf(tdata->attr_name[i], CORETEMP_NAME_LENGTH,
441 "temp%d_%s", attr_no, suffixes[i]);
442 sysfs_attr_init(&tdata->sd_attrs[i].dev_attr.attr);
443 tdata->sd_attrs[i].dev_attr.attr.name = tdata->attr_name[i];
444 tdata->sd_attrs[i].dev_attr.attr.mode = 0444;
445 tdata->sd_attrs[i].dev_attr.show = rd_ptr[i];
446 tdata->sd_attrs[i].index = attr_no;
447 tdata->attrs[i] = &tdata->sd_attrs[i].dev_attr.attr;
449 tdata->attr_group.attrs = tdata->attrs;
450 return sysfs_create_group(&dev->kobj, &tdata->attr_group);
454 static int chk_ucode_version(unsigned int cpu)
456 struct cpuinfo_x86 *c = &cpu_data(cpu);
459 * Check if we have problem with errata AE18 of Core processors:
460 * Readings might stop update when processor visited too deep sleep,
461 * fixed for stepping D0 (6EC).
463 if (c->x86_model == 0xe && c->x86_stepping < 0xc && c->microcode < 0x39) {
464 pr_err("Errata AE18 not fixed, update BIOS or microcode of the CPU!\n");
470 static struct platform_device *coretemp_get_pdev(unsigned int cpu)
472 int id = topology_logical_die_id(cpu);
474 if (id >= 0 && id < max_zones)
475 return zone_devices[id];
479 static struct temp_data *init_temp_data(unsigned int cpu, int pkg_flag)
481 struct temp_data *tdata;
483 tdata = kzalloc(sizeof(struct temp_data), GFP_KERNEL);
487 tdata->status_reg = pkg_flag ? MSR_IA32_PACKAGE_THERM_STATUS :
488 MSR_IA32_THERM_STATUS;
489 tdata->is_pkg_data = pkg_flag;
491 tdata->cpu_core_id = topology_core_id(cpu);
492 tdata->attr_size = MAX_CORE_ATTRS;
493 mutex_init(&tdata->update_lock);
497 static int create_core_data(struct platform_device *pdev, unsigned int cpu,
500 struct temp_data *tdata;
501 struct platform_data *pdata = platform_get_drvdata(pdev);
502 struct cpuinfo_x86 *c = &cpu_data(cpu);
504 int err, index, attr_no;
506 if (!housekeeping_cpu(cpu, HK_TYPE_MISC))
510 * Find attr number for sysfs:
511 * We map the attr number to core id of the CPU
512 * The attr number is always core id + 2
513 * The Pkgtemp will always show up as temp1_*, if available
516 attr_no = PKG_SYSFS_ATTR_NO;
518 index = ida_alloc(&pdata->ida, GFP_KERNEL);
521 pdata->cpu_map[index] = topology_core_id(cpu);
522 attr_no = index + BASE_SYSFS_ATTR_NO;
525 if (attr_no > MAX_CORE_DATA - 1) {
530 tdata = init_temp_data(cpu, pkg_flag);
536 /* Test if we can access the status register */
537 err = rdmsr_safe_on_cpu(cpu, tdata->status_reg, &eax, &edx);
541 /* Make sure tdata->tjmax is a valid indicator for dynamic/static tjmax */
542 get_tjmax(tdata, &pdev->dev);
545 * The target temperature is available on older CPUs but not in the
546 * MSR_IA32_TEMPERATURE_TARGET register. Atoms don't have the register
549 if (c->x86_model > 0xe && c->x86_model != 0x1c)
550 if (get_ttarget(tdata, &pdev->dev) >= 0)
553 pdata->core_data[attr_no] = tdata;
555 /* Create sysfs interfaces */
556 err = create_core_attrs(tdata, pdata->hwmon_dev, attr_no);
562 pdata->core_data[attr_no] = NULL;
566 ida_free(&pdata->ida, index);
571 coretemp_add_core(struct platform_device *pdev, unsigned int cpu, int pkg_flag)
573 if (create_core_data(pdev, cpu, pkg_flag))
574 dev_err(&pdev->dev, "Adding Core %u failed\n", cpu);
577 static void coretemp_remove_core(struct platform_data *pdata, int indx)
579 struct temp_data *tdata = pdata->core_data[indx];
581 /* if we errored on add then this is already gone */
585 /* Remove the sysfs attributes */
586 sysfs_remove_group(&pdata->hwmon_dev->kobj, &tdata->attr_group);
588 kfree(pdata->core_data[indx]);
589 pdata->core_data[indx] = NULL;
591 if (indx >= BASE_SYSFS_ATTR_NO)
592 ida_free(&pdata->ida, indx - BASE_SYSFS_ATTR_NO);
595 static int coretemp_device_add(int zoneid)
597 struct platform_device *pdev;
598 struct platform_data *pdata;
601 /* Initialize the per-zone data structures */
602 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
606 pdata->pkg_id = zoneid;
607 ida_init(&pdata->ida);
609 pdev = platform_device_alloc(DRVNAME, zoneid);
615 err = platform_device_add(pdev);
619 platform_set_drvdata(pdev, pdata);
620 zone_devices[zoneid] = pdev;
624 platform_device_put(pdev);
630 static void coretemp_device_remove(int zoneid)
632 struct platform_device *pdev = zone_devices[zoneid];
633 struct platform_data *pdata = platform_get_drvdata(pdev);
635 ida_destroy(&pdata->ida);
637 platform_device_unregister(pdev);
640 static int coretemp_cpu_online(unsigned int cpu)
642 struct platform_device *pdev = coretemp_get_pdev(cpu);
643 struct cpuinfo_x86 *c = &cpu_data(cpu);
644 struct platform_data *pdata;
647 * Don't execute this on resume as the offline callback did
648 * not get executed on suspend.
650 if (cpuhp_tasks_frozen)
654 * CPUID.06H.EAX[0] indicates whether the CPU has thermal
655 * sensors. We check this bit only, all the early CPUs
656 * without thermal sensors will be filtered out.
658 if (!cpu_has(c, X86_FEATURE_DTHERM))
661 pdata = platform_get_drvdata(pdev);
662 if (!pdata->hwmon_dev) {
663 struct device *hwmon;
665 /* Check the microcode version of the CPU */
666 if (chk_ucode_version(cpu))
670 * Alright, we have DTS support.
671 * We are bringing the _first_ core in this pkg
672 * online. So, initialize per-pkg data structures and
673 * then bring this core online.
675 hwmon = hwmon_device_register_with_groups(&pdev->dev, DRVNAME,
678 return PTR_ERR(hwmon);
679 pdata->hwmon_dev = hwmon;
682 * Check whether pkgtemp support is available.
683 * If so, add interfaces for pkgtemp.
685 if (cpu_has(c, X86_FEATURE_PTS))
686 coretemp_add_core(pdev, cpu, 1);
690 * Check whether a thread sibling is already online. If not add the
691 * interface for this CPU core.
693 if (!cpumask_intersects(&pdata->cpumask, topology_sibling_cpumask(cpu)))
694 coretemp_add_core(pdev, cpu, 0);
696 cpumask_set_cpu(cpu, &pdata->cpumask);
700 static int coretemp_cpu_offline(unsigned int cpu)
702 struct platform_device *pdev = coretemp_get_pdev(cpu);
703 struct platform_data *pd;
704 struct temp_data *tdata;
705 int i, indx = -1, target;
707 /* No need to tear down any interfaces for suspend */
708 if (cpuhp_tasks_frozen)
711 /* If the physical CPU device does not exist, just return */
712 pd = platform_get_drvdata(pdev);
716 for (i = 0; i < NUM_REAL_CORES; i++) {
717 if (pd->cpu_map[i] == topology_core_id(cpu)) {
718 indx = i + BASE_SYSFS_ATTR_NO;
723 /* Too many cores and this core is not populated, just return */
727 tdata = pd->core_data[indx];
729 cpumask_clear_cpu(cpu, &pd->cpumask);
732 * If this is the last thread sibling, remove the CPU core
733 * interface, If there is still a sibling online, transfer the
734 * target cpu of that core interface to it.
736 target = cpumask_any_and(&pd->cpumask, topology_sibling_cpumask(cpu));
737 if (target >= nr_cpu_ids) {
738 coretemp_remove_core(pd, indx);
739 } else if (tdata && tdata->cpu == cpu) {
740 mutex_lock(&tdata->update_lock);
742 mutex_unlock(&tdata->update_lock);
746 * If all cores in this pkg are offline, remove the interface.
748 tdata = pd->core_data[PKG_SYSFS_ATTR_NO];
749 if (cpumask_empty(&pd->cpumask)) {
751 coretemp_remove_core(pd, PKG_SYSFS_ATTR_NO);
752 hwmon_device_unregister(pd->hwmon_dev);
753 pd->hwmon_dev = NULL;
758 * Check whether this core is the target for the package
759 * interface. We need to assign it to some other cpu.
761 if (tdata && tdata->cpu == cpu) {
762 target = cpumask_first(&pd->cpumask);
763 mutex_lock(&tdata->update_lock);
765 mutex_unlock(&tdata->update_lock);
769 static const struct x86_cpu_id __initconst coretemp_ids[] = {
770 X86_MATCH_VENDOR_FEATURE(INTEL, X86_FEATURE_DTHERM, NULL),
773 MODULE_DEVICE_TABLE(x86cpu, coretemp_ids);
775 static enum cpuhp_state coretemp_hp_online;
777 static int __init coretemp_init(void)
782 * CPUID.06H.EAX[0] indicates whether the CPU has thermal
783 * sensors. We check this bit only, all the early CPUs
784 * without thermal sensors will be filtered out.
786 if (!x86_match_cpu(coretemp_ids))
789 max_zones = topology_max_packages() * topology_max_die_per_package();
790 zone_devices = kcalloc(max_zones, sizeof(struct platform_device *),
795 for (i = 0; i < max_zones; i++) {
796 err = coretemp_device_add(i);
801 err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hwmon/coretemp:online",
802 coretemp_cpu_online, coretemp_cpu_offline);
805 coretemp_hp_online = err;
810 coretemp_device_remove(i);
814 module_init(coretemp_init)
816 static void __exit coretemp_exit(void)
820 cpuhp_remove_state(coretemp_hp_online);
821 for (i = 0; i < max_zones; i++)
822 coretemp_device_remove(i);
825 module_exit(coretemp_exit)
828 MODULE_DESCRIPTION("Intel Core temperature monitor");
829 MODULE_LICENSE("GPL");