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>
31 #define DRVNAME "coretemp"
34 * force_tjmax only matters when TjMax can't be read from the CPU itself.
35 * When set, it replaces the driver's suboptimal heuristic.
37 static int force_tjmax;
38 module_param_named(tjmax, force_tjmax, int, 0444);
39 MODULE_PARM_DESC(tjmax, "TjMax value in degrees Celsius");
41 #define PKG_SYSFS_ATTR_NO 1 /* Sysfs attribute for package temp */
42 #define BASE_SYSFS_ATTR_NO 2 /* Sysfs Base attr no for coretemp */
43 #define NUM_REAL_CORES 128 /* Number of Real cores per cpu */
44 #define CORETEMP_NAME_LENGTH 19 /* String Length of attrs */
45 #define MAX_CORE_ATTRS 4 /* Maximum no of basic attrs */
46 #define TOTAL_ATTRS (MAX_CORE_ATTRS + 1)
47 #define MAX_CORE_DATA (NUM_REAL_CORES + BASE_SYSFS_ATTR_NO)
50 #define for_each_sibling(i, cpu) \
51 for_each_cpu(i, topology_sibling_cpumask(cpu))
53 #define for_each_sibling(i, cpu) for (i = 0; false; )
57 * Per-Core Temperature Data
58 * @tjmax: The static tjmax value when tjmax cannot be retrieved from
59 * IA32_TEMPERATURE_TARGET MSR.
60 * @last_updated: The time when the current temperature value was updated
61 * earlier (in jiffies).
62 * @cpu_core_id: The CPU Core from which temperature values should be read
63 * This value is passed as "id" field to rdmsr/wrmsr functions.
64 * @status_reg: One of IA32_THERM_STATUS or IA32_PACKAGE_THERM_STATUS,
65 * from where the temperature values should be read.
66 * @attr_size: Total number of pre-core attrs displayed in the sysfs.
67 * @is_pkg_data: If this is 1, the temp_data holds pkgtemp data.
68 * Otherwise, temp_data holds coretemp data.
73 unsigned long last_updated;
79 struct sensor_device_attribute sd_attrs[TOTAL_ATTRS];
80 char attr_name[TOTAL_ATTRS][CORETEMP_NAME_LENGTH];
81 struct attribute *attrs[TOTAL_ATTRS + 1];
82 struct attribute_group attr_group;
83 struct mutex update_lock;
86 /* Platform Data per Physical CPU */
87 struct platform_data {
88 struct device *hwmon_dev;
90 u16 cpu_map[NUM_REAL_CORES];
92 struct cpumask cpumask;
93 struct temp_data *core_data[MAX_CORE_DATA];
94 struct device_attribute name_attr;
102 static const struct tjmax_pci tjmax_pci_table[] = {
103 { 0x0708, 110000 }, /* CE41x0 (Sodaville ) */
104 { 0x0c72, 102000 }, /* Atom S1240 (Centerton) */
105 { 0x0c73, 95000 }, /* Atom S1220 (Centerton) */
106 { 0x0c75, 95000 }, /* Atom S1260 (Centerton) */
114 static const struct tjmax tjmax_table[] = {
115 { "CPU 230", 100000 }, /* Model 0x1c, stepping 2 */
116 { "CPU 330", 125000 }, /* Model 0x1c, stepping 2 */
127 static const struct tjmax_model tjmax_model_table[] = {
128 { 0x1c, 10, 100000 }, /* D4xx, K4xx, N4xx, D5xx, K5xx, N5xx */
129 { 0x1c, ANY, 90000 }, /* Z5xx, N2xx, possibly others
130 * Note: Also matches 230 and 330,
131 * which are covered by tjmax_table
133 { 0x26, ANY, 90000 }, /* Atom Tunnel Creek (Exx), Lincroft (Z6xx)
134 * Note: TjMax for E6xxT is 110C, but CPU type
135 * is undetectable by software
137 { 0x27, ANY, 90000 }, /* Atom Medfield (Z2460) */
138 { 0x35, ANY, 90000 }, /* Atom Clover Trail/Cloverview (Z27x0) */
139 { 0x36, ANY, 100000 }, /* Atom Cedar Trail/Cedarview (N2xxx, D2xxx)
140 * Also matches S12x0 (stepping 9), covered by
145 static int adjust_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *dev)
147 /* The 100C is default for both mobile and non mobile CPUs */
150 int tjmax_ee = 85000;
155 u16 devfn = PCI_DEVFN(0, 0);
156 struct pci_dev *host_bridge = pci_get_domain_bus_and_slot(0, 0, devfn);
159 * Explicit tjmax table entries override heuristics.
160 * First try PCI host bridge IDs, followed by model ID strings
161 * and model/stepping information.
163 if (host_bridge && host_bridge->vendor == PCI_VENDOR_ID_INTEL) {
164 for (i = 0; i < ARRAY_SIZE(tjmax_pci_table); i++) {
165 if (host_bridge->device == tjmax_pci_table[i].device) {
166 pci_dev_put(host_bridge);
167 return tjmax_pci_table[i].tjmax;
171 pci_dev_put(host_bridge);
173 for (i = 0; i < ARRAY_SIZE(tjmax_table); i++) {
174 if (strstr(c->x86_model_id, tjmax_table[i].id))
175 return tjmax_table[i].tjmax;
178 for (i = 0; i < ARRAY_SIZE(tjmax_model_table); i++) {
179 const struct tjmax_model *tm = &tjmax_model_table[i];
180 if (c->x86_model == tm->model &&
181 (tm->mask == ANY || c->x86_stepping == tm->mask))
185 /* Early chips have no MSR for TjMax */
187 if (c->x86_model == 0xf && c->x86_stepping < 4)
190 if (c->x86_model > 0xe && usemsr_ee) {
194 * Now we can detect the mobile CPU using Intel provided table
195 * http://softwarecommunity.intel.com/Wiki/Mobility/720.htm
196 * For Core2 cores, check MSR 0x17, bit 28 1 = Mobile CPU
198 err = rdmsr_safe_on_cpu(id, 0x17, &eax, &edx);
201 "Unable to access MSR 0x17, assuming desktop"
204 } else if (c->x86_model < 0x17 && !(eax & 0x10000000)) {
206 * Trust bit 28 up to Penryn, I could not find any
207 * documentation on that; if you happen to know
208 * someone at Intel please ask
212 /* Platform ID bits 52:50 (EDX starts at bit 32) */
213 platform_id = (edx >> 18) & 0x7;
216 * Mobile Penryn CPU seems to be platform ID 7 or 5
219 if (c->x86_model == 0x17 &&
220 (platform_id == 5 || platform_id == 7)) {
222 * If MSR EE bit is set, set it to 90 degrees C,
223 * otherwise 105 degrees C
232 err = rdmsr_safe_on_cpu(id, 0xee, &eax, &edx);
235 "Unable to access MSR 0xEE, for Tjmax, left"
237 } else if (eax & 0x40000000) {
240 } else if (tjmax == 100000) {
242 * If we don't use msr EE it means we are desktop CPU
243 * (with exeception of Atom)
245 dev_warn(dev, "Using relative temperature scale!\n");
251 static bool cpu_has_tjmax(struct cpuinfo_x86 *c)
253 u8 model = c->x86_model;
255 return model > 0xe &&
263 static int get_tjmax(struct temp_data *tdata, struct device *dev)
265 struct cpuinfo_x86 *c = &cpu_data(tdata->cpu);
270 /* use static tjmax once it is set */
275 * A new feature of current Intel(R) processors, the
276 * IA32_TEMPERATURE_TARGET contains the TjMax value
278 err = rdmsr_safe_on_cpu(tdata->cpu, MSR_IA32_TEMPERATURE_TARGET, &eax, &edx);
280 if (cpu_has_tjmax(c))
281 dev_warn(dev, "Unable to read TjMax from CPU %u\n", tdata->cpu);
283 val = (eax >> 16) & 0xff;
285 * If the TjMax is not plausible, an assumption
289 dev_dbg(dev, "TjMax is %d degrees C\n", val);
295 dev_notice(dev, "TjMax forced to %d degrees C by user\n",
297 tdata->tjmax = force_tjmax * 1000;
300 * An assumption is made for early CPUs and unreadable MSR.
301 * NOTE: the calculated value may not be correct.
303 tdata->tjmax = adjust_tjmax(c, tdata->cpu, dev);
308 static int get_ttarget(struct temp_data *tdata, struct device *dev)
311 int tjmax, ttarget_offset, ret;
314 * ttarget is valid only if tjmax can be retrieved from
315 * MSR_IA32_TEMPERATURE_TARGET
320 ret = rdmsr_safe_on_cpu(tdata->cpu, MSR_IA32_TEMPERATURE_TARGET, &eax, &edx);
324 tjmax = (eax >> 16) & 0xff;
326 /* Read the still undocumented bits 8:15 of IA32_TEMPERATURE_TARGET. */
327 ttarget_offset = (eax >> 8) & 0xff;
329 return (tjmax - ttarget_offset) * 1000;
332 /* Keep track of how many zone pointers we allocated in init() */
333 static int max_zones __read_mostly;
334 /* Array of zone pointers. Serialized by cpu hotplug lock */
335 static struct platform_device **zone_devices;
337 static ssize_t show_label(struct device *dev,
338 struct device_attribute *devattr, char *buf)
340 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
341 struct platform_data *pdata = dev_get_drvdata(dev);
342 struct temp_data *tdata = pdata->core_data[attr->index];
344 if (tdata->is_pkg_data)
345 return sprintf(buf, "Package id %u\n", pdata->pkg_id);
347 return sprintf(buf, "Core %u\n", tdata->cpu_core_id);
350 static ssize_t show_crit_alarm(struct device *dev,
351 struct device_attribute *devattr, char *buf)
354 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
355 struct platform_data *pdata = dev_get_drvdata(dev);
356 struct temp_data *tdata = pdata->core_data[attr->index];
358 mutex_lock(&tdata->update_lock);
359 rdmsr_on_cpu(tdata->cpu, tdata->status_reg, &eax, &edx);
360 mutex_unlock(&tdata->update_lock);
362 return sprintf(buf, "%d\n", (eax >> 5) & 1);
365 static ssize_t show_tjmax(struct device *dev,
366 struct device_attribute *devattr, char *buf)
368 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
369 struct platform_data *pdata = dev_get_drvdata(dev);
370 struct temp_data *tdata = pdata->core_data[attr->index];
373 mutex_lock(&tdata->update_lock);
374 tjmax = get_tjmax(tdata, dev);
375 mutex_unlock(&tdata->update_lock);
377 return sprintf(buf, "%d\n", tjmax);
380 static ssize_t show_ttarget(struct device *dev,
381 struct device_attribute *devattr, char *buf)
383 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
384 struct platform_data *pdata = dev_get_drvdata(dev);
385 struct temp_data *tdata = pdata->core_data[attr->index];
388 mutex_lock(&tdata->update_lock);
389 ttarget = get_ttarget(tdata, dev);
390 mutex_unlock(&tdata->update_lock);
394 return sprintf(buf, "%d\n", ttarget);
397 static ssize_t show_temp(struct device *dev,
398 struct device_attribute *devattr, char *buf)
401 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
402 struct platform_data *pdata = dev_get_drvdata(dev);
403 struct temp_data *tdata = pdata->core_data[attr->index];
406 mutex_lock(&tdata->update_lock);
408 tjmax = get_tjmax(tdata, dev);
409 /* Check whether the time interval has elapsed */
410 if (time_after(jiffies, tdata->last_updated + HZ)) {
411 rdmsr_on_cpu(tdata->cpu, tdata->status_reg, &eax, &edx);
413 * Ignore the valid bit. In all observed cases the register
414 * value is either low or zero if the valid bit is 0.
415 * Return it instead of reporting an error which doesn't
416 * really help at all.
418 tdata->temp = tjmax - ((eax >> 16) & 0x7f) * 1000;
419 tdata->last_updated = jiffies;
422 mutex_unlock(&tdata->update_lock);
423 return sprintf(buf, "%d\n", tdata->temp);
426 static int create_core_attrs(struct temp_data *tdata, struct device *dev,
430 static ssize_t (*const rd_ptr[TOTAL_ATTRS]) (struct device *dev,
431 struct device_attribute *devattr, char *buf) = {
432 show_label, show_crit_alarm, show_temp, show_tjmax,
434 static const char *const suffixes[TOTAL_ATTRS] = {
435 "label", "crit_alarm", "input", "crit", "max"
438 for (i = 0; i < tdata->attr_size; i++) {
439 snprintf(tdata->attr_name[i], CORETEMP_NAME_LENGTH,
440 "temp%d_%s", attr_no, suffixes[i]);
441 sysfs_attr_init(&tdata->sd_attrs[i].dev_attr.attr);
442 tdata->sd_attrs[i].dev_attr.attr.name = tdata->attr_name[i];
443 tdata->sd_attrs[i].dev_attr.attr.mode = 0444;
444 tdata->sd_attrs[i].dev_attr.show = rd_ptr[i];
445 tdata->sd_attrs[i].index = attr_no;
446 tdata->attrs[i] = &tdata->sd_attrs[i].dev_attr.attr;
448 tdata->attr_group.attrs = tdata->attrs;
449 return sysfs_create_group(&dev->kobj, &tdata->attr_group);
453 static int chk_ucode_version(unsigned int cpu)
455 struct cpuinfo_x86 *c = &cpu_data(cpu);
458 * Check if we have problem with errata AE18 of Core processors:
459 * Readings might stop update when processor visited too deep sleep,
460 * fixed for stepping D0 (6EC).
462 if (c->x86_model == 0xe && c->x86_stepping < 0xc && c->microcode < 0x39) {
463 pr_err("Errata AE18 not fixed, update BIOS or microcode of the CPU!\n");
469 static struct platform_device *coretemp_get_pdev(unsigned int cpu)
471 int id = topology_logical_die_id(cpu);
473 if (id >= 0 && id < max_zones)
474 return zone_devices[id];
478 static struct temp_data *init_temp_data(unsigned int cpu, int pkg_flag)
480 struct temp_data *tdata;
482 tdata = kzalloc(sizeof(struct temp_data), GFP_KERNEL);
486 tdata->status_reg = pkg_flag ? MSR_IA32_PACKAGE_THERM_STATUS :
487 MSR_IA32_THERM_STATUS;
488 tdata->is_pkg_data = pkg_flag;
490 tdata->cpu_core_id = topology_core_id(cpu);
491 tdata->attr_size = MAX_CORE_ATTRS;
492 mutex_init(&tdata->update_lock);
496 static int create_core_data(struct platform_device *pdev, unsigned int cpu,
499 struct temp_data *tdata;
500 struct platform_data *pdata = platform_get_drvdata(pdev);
501 struct cpuinfo_x86 *c = &cpu_data(cpu);
503 int err, index, attr_no;
506 * Find attr number for sysfs:
507 * We map the attr number to core id of the CPU
508 * The attr number is always core id + 2
509 * The Pkgtemp will always show up as temp1_*, if available
512 attr_no = PKG_SYSFS_ATTR_NO;
514 index = ida_alloc(&pdata->ida, GFP_KERNEL);
517 pdata->cpu_map[index] = topology_core_id(cpu);
518 attr_no = index + BASE_SYSFS_ATTR_NO;
521 if (attr_no > MAX_CORE_DATA - 1) {
526 tdata = init_temp_data(cpu, pkg_flag);
532 /* Test if we can access the status register */
533 err = rdmsr_safe_on_cpu(cpu, tdata->status_reg, &eax, &edx);
537 /* Make sure tdata->tjmax is a valid indicator for dynamic/static tjmax */
538 get_tjmax(tdata, &pdev->dev);
541 * The target temperature is available on older CPUs but not in the
542 * MSR_IA32_TEMPERATURE_TARGET register. Atoms don't have the register
545 if (c->x86_model > 0xe && c->x86_model != 0x1c)
546 if (get_ttarget(tdata, &pdev->dev) >= 0)
549 pdata->core_data[attr_no] = tdata;
551 /* Create sysfs interfaces */
552 err = create_core_attrs(tdata, pdata->hwmon_dev, attr_no);
558 pdata->core_data[attr_no] = NULL;
562 ida_free(&pdata->ida, index);
567 coretemp_add_core(struct platform_device *pdev, unsigned int cpu, int pkg_flag)
569 if (create_core_data(pdev, cpu, pkg_flag))
570 dev_err(&pdev->dev, "Adding Core %u failed\n", cpu);
573 static void coretemp_remove_core(struct platform_data *pdata, int indx)
575 struct temp_data *tdata = pdata->core_data[indx];
577 /* if we errored on add then this is already gone */
581 /* Remove the sysfs attributes */
582 sysfs_remove_group(&pdata->hwmon_dev->kobj, &tdata->attr_group);
584 kfree(pdata->core_data[indx]);
585 pdata->core_data[indx] = NULL;
587 if (indx >= BASE_SYSFS_ATTR_NO)
588 ida_free(&pdata->ida, indx - BASE_SYSFS_ATTR_NO);
591 static int coretemp_probe(struct platform_device *pdev)
593 struct device *dev = &pdev->dev;
594 struct platform_data *pdata;
596 /* Initialize the per-zone data structures */
597 pdata = devm_kzalloc(dev, sizeof(struct platform_data), GFP_KERNEL);
601 pdata->pkg_id = pdev->id;
602 ida_init(&pdata->ida);
603 platform_set_drvdata(pdev, pdata);
605 pdata->hwmon_dev = devm_hwmon_device_register_with_groups(dev, DRVNAME,
607 return PTR_ERR_OR_ZERO(pdata->hwmon_dev);
610 static int coretemp_remove(struct platform_device *pdev)
612 struct platform_data *pdata = platform_get_drvdata(pdev);
615 for (i = MAX_CORE_DATA - 1; i >= 0; --i)
616 if (pdata->core_data[i])
617 coretemp_remove_core(pdata, i);
619 ida_destroy(&pdata->ida);
623 static struct platform_driver coretemp_driver = {
627 .probe = coretemp_probe,
628 .remove = coretemp_remove,
631 static struct platform_device *coretemp_device_add(unsigned int cpu)
633 int err, zoneid = topology_logical_die_id(cpu);
634 struct platform_device *pdev;
637 return ERR_PTR(-ENOMEM);
639 pdev = platform_device_alloc(DRVNAME, zoneid);
641 return ERR_PTR(-ENOMEM);
643 err = platform_device_add(pdev);
645 platform_device_put(pdev);
649 zone_devices[zoneid] = pdev;
653 static int coretemp_cpu_online(unsigned int cpu)
655 struct platform_device *pdev = coretemp_get_pdev(cpu);
656 struct cpuinfo_x86 *c = &cpu_data(cpu);
657 struct platform_data *pdata;
660 * Don't execute this on resume as the offline callback did
661 * not get executed on suspend.
663 if (cpuhp_tasks_frozen)
667 * CPUID.06H.EAX[0] indicates whether the CPU has thermal
668 * sensors. We check this bit only, all the early CPUs
669 * without thermal sensors will be filtered out.
671 if (!cpu_has(c, X86_FEATURE_DTHERM))
675 /* Check the microcode version of the CPU */
676 if (chk_ucode_version(cpu))
680 * Alright, we have DTS support.
681 * We are bringing the _first_ core in this pkg
682 * online. So, initialize per-pkg data structures and
683 * then bring this core online.
685 pdev = coretemp_device_add(cpu);
687 return PTR_ERR(pdev);
690 * Check whether pkgtemp support is available.
691 * If so, add interfaces for pkgtemp.
693 if (cpu_has(c, X86_FEATURE_PTS))
694 coretemp_add_core(pdev, cpu, 1);
697 pdata = platform_get_drvdata(pdev);
699 * Check whether a thread sibling is already online. If not add the
700 * interface for this CPU core.
702 if (!cpumask_intersects(&pdata->cpumask, topology_sibling_cpumask(cpu)))
703 coretemp_add_core(pdev, cpu, 0);
705 cpumask_set_cpu(cpu, &pdata->cpumask);
709 static int coretemp_cpu_offline(unsigned int cpu)
711 struct platform_device *pdev = coretemp_get_pdev(cpu);
712 struct platform_data *pd;
713 struct temp_data *tdata;
714 int i, indx = -1, target;
717 * Don't execute this on suspend as the device remove locks
720 if (cpuhp_tasks_frozen)
723 /* If the physical CPU device does not exist, just return */
727 pd = platform_get_drvdata(pdev);
729 for (i = 0; i < NUM_REAL_CORES; i++) {
730 if (pd->cpu_map[i] == topology_core_id(cpu)) {
731 indx = i + BASE_SYSFS_ATTR_NO;
736 /* Too many cores and this core is not populated, just return */
740 tdata = pd->core_data[indx];
742 cpumask_clear_cpu(cpu, &pd->cpumask);
745 * If this is the last thread sibling, remove the CPU core
746 * interface, If there is still a sibling online, transfer the
747 * target cpu of that core interface to it.
749 target = cpumask_any_and(&pd->cpumask, topology_sibling_cpumask(cpu));
750 if (target >= nr_cpu_ids) {
751 coretemp_remove_core(pd, indx);
752 } else if (tdata && tdata->cpu == cpu) {
753 mutex_lock(&tdata->update_lock);
755 mutex_unlock(&tdata->update_lock);
759 * If all cores in this pkg are offline, remove the device. This
760 * will invoke the platform driver remove function, which cleans up
763 if (cpumask_empty(&pd->cpumask)) {
764 zone_devices[topology_logical_die_id(cpu)] = NULL;
765 platform_device_unregister(pdev);
770 * Check whether this core is the target for the package
771 * interface. We need to assign it to some other cpu.
773 tdata = pd->core_data[PKG_SYSFS_ATTR_NO];
774 if (tdata && tdata->cpu == cpu) {
775 target = cpumask_first(&pd->cpumask);
776 mutex_lock(&tdata->update_lock);
778 mutex_unlock(&tdata->update_lock);
782 static const struct x86_cpu_id __initconst coretemp_ids[] = {
783 X86_MATCH_VENDOR_FEATURE(INTEL, X86_FEATURE_DTHERM, NULL),
786 MODULE_DEVICE_TABLE(x86cpu, coretemp_ids);
788 static enum cpuhp_state coretemp_hp_online;
790 static int __init coretemp_init(void)
795 * CPUID.06H.EAX[0] indicates whether the CPU has thermal
796 * sensors. We check this bit only, all the early CPUs
797 * without thermal sensors will be filtered out.
799 if (!x86_match_cpu(coretemp_ids))
802 max_zones = topology_max_packages() * topology_max_die_per_package();
803 zone_devices = kcalloc(max_zones, sizeof(struct platform_device *),
808 err = platform_driver_register(&coretemp_driver);
812 err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hwmon/coretemp:online",
813 coretemp_cpu_online, coretemp_cpu_offline);
816 coretemp_hp_online = err;
820 platform_driver_unregister(&coretemp_driver);
825 module_init(coretemp_init)
827 static void __exit coretemp_exit(void)
829 cpuhp_remove_state(coretemp_hp_online);
830 platform_driver_unregister(&coretemp_driver);
833 module_exit(coretemp_exit)
836 MODULE_DESCRIPTION("Intel Core temperature monitor");
837 MODULE_LICENSE("GPL");