2 * coretemp.c - Linux kernel module for hardware monitoring
4 * Copyright (C) 2007 Rudolf Marek <r.marek@assembler.cz>
6 * Inspired from many hwmon drivers
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; version 2 of the License.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
23 #include <linux/module.h>
24 #include <linux/delay.h>
25 #include <linux/init.h>
26 #include <linux/slab.h>
27 #include <linux/jiffies.h>
28 #include <linux/hwmon.h>
29 #include <linux/sysfs.h>
30 #include <linux/hwmon-sysfs.h>
31 #include <linux/err.h>
32 #include <linux/mutex.h>
33 #include <linux/list.h>
34 #include <linux/platform_device.h>
35 #include <linux/cpu.h>
36 #include <linux/pci.h>
38 #include <asm/processor.h>
41 #define DRVNAME "coretemp"
43 typedef enum { SHOW_TEMP
, SHOW_TJMAX
, SHOW_TTARGET
, SHOW_LABEL
,
47 * Functions declaration
50 static struct coretemp_data
*coretemp_update_device(struct device
*dev
);
52 struct coretemp_data
{
53 struct device
*hwmon_dev
;
54 struct mutex update_lock
;
58 char valid
; /* zero until following fields are valid */
59 unsigned long last_updated
; /* in jiffies */
70 static ssize_t
show_name(struct device
*dev
, struct device_attribute
74 struct sensor_device_attribute
*attr
= to_sensor_dev_attr(devattr
);
75 struct coretemp_data
*data
= dev_get_drvdata(dev
);
77 if (attr
->index
== SHOW_NAME
)
78 ret
= sprintf(buf
, "%s\n", data
->name
);
80 ret
= sprintf(buf
, "Core %d\n", data
->core_id
);
84 static ssize_t
show_alarm(struct device
*dev
, struct device_attribute
87 struct coretemp_data
*data
= coretemp_update_device(dev
);
88 /* read the Out-of-spec log, never clear */
89 return sprintf(buf
, "%d\n", data
->alarm
);
92 static ssize_t
show_temp(struct device
*dev
,
93 struct device_attribute
*devattr
, char *buf
)
95 struct sensor_device_attribute
*attr
= to_sensor_dev_attr(devattr
);
96 struct coretemp_data
*data
= coretemp_update_device(dev
);
99 if (attr
->index
== SHOW_TEMP
)
100 err
= data
->valid
? sprintf(buf
, "%d\n", data
->temp
) : -EAGAIN
;
101 else if (attr
->index
== SHOW_TJMAX
)
102 err
= sprintf(buf
, "%d\n", data
->tjmax
);
104 err
= sprintf(buf
, "%d\n", data
->ttarget
);
108 static SENSOR_DEVICE_ATTR(temp1_input
, S_IRUGO
, show_temp
, NULL
,
110 static SENSOR_DEVICE_ATTR(temp1_crit
, S_IRUGO
, show_temp
, NULL
,
112 static SENSOR_DEVICE_ATTR(temp1_max
, S_IRUGO
, show_temp
, NULL
,
114 static DEVICE_ATTR(temp1_crit_alarm
, S_IRUGO
, show_alarm
, NULL
);
115 static SENSOR_DEVICE_ATTR(temp1_label
, S_IRUGO
, show_name
, NULL
, SHOW_LABEL
);
116 static SENSOR_DEVICE_ATTR(name
, S_IRUGO
, show_name
, NULL
, SHOW_NAME
);
118 static struct attribute
*coretemp_attributes
[] = {
119 &sensor_dev_attr_name
.dev_attr
.attr
,
120 &sensor_dev_attr_temp1_label
.dev_attr
.attr
,
121 &dev_attr_temp1_crit_alarm
.attr
,
122 &sensor_dev_attr_temp1_input
.dev_attr
.attr
,
123 &sensor_dev_attr_temp1_crit
.dev_attr
.attr
,
127 static const struct attribute_group coretemp_group
= {
128 .attrs
= coretemp_attributes
,
131 static struct coretemp_data
*coretemp_update_device(struct device
*dev
)
133 struct coretemp_data
*data
= dev_get_drvdata(dev
);
135 mutex_lock(&data
->update_lock
);
137 if (!data
->valid
|| time_after(jiffies
, data
->last_updated
+ HZ
)) {
141 rdmsr_on_cpu(data
->id
, MSR_IA32_THERM_STATUS
, &eax
, &edx
);
142 data
->alarm
= (eax
>> 5) & 1;
143 /* update only if data has been valid */
144 if (eax
& 0x80000000) {
145 data
->temp
= data
->tjmax
- (((eax
>> 16)
149 dev_dbg(dev
, "Temperature data invalid (0x%x)\n", eax
);
151 data
->last_updated
= jiffies
;
154 mutex_unlock(&data
->update_lock
);
158 static int __devinit
adjust_tjmax(struct cpuinfo_x86
*c
, u32 id
, struct device
*dev
)
160 /* The 100C is default for both mobile and non mobile CPUs */
163 int tjmax_ee
= 85000;
167 struct pci_dev
*host_bridge
;
169 /* Early chips have no MSR for TjMax */
171 if ((c
->x86_model
== 0xf) && (c
->x86_mask
< 4)) {
177 if (c
->x86_model
== 0x1c) {
180 host_bridge
= pci_get_bus_and_slot(0, PCI_DEVFN(0, 0));
182 if (host_bridge
&& host_bridge
->vendor
== PCI_VENDOR_ID_INTEL
183 && (host_bridge
->device
== 0xa000 /* NM10 based nettop */
184 || host_bridge
->device
== 0xa010)) /* NM10 based netbook */
189 pci_dev_put(host_bridge
);
192 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
200 err
= rdmsr_safe_on_cpu(id
, 0x17, &eax
, &edx
);
203 "Unable to access MSR 0x17, assuming desktop"
206 } 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 */
212 /* Platform ID bits 52:50 (EDX starts at bit 32) */
213 platform_id
= (edx
>> 18) & 0x7;
215 /* Mobile Penryn CPU seems to be platform ID 7 or 5
217 if ((c
->x86_model
== 0x17) &&
218 ((platform_id
== 5) || (platform_id
== 7))) {
219 /* If MSR EE bit is set, set it to 90 degrees C,
220 otherwise 105 degrees C */
229 err
= rdmsr_safe_on_cpu(id
, 0xee, &eax
, &edx
);
232 "Unable to access MSR 0xEE, for Tjmax, left"
234 } else if (eax
& 0x40000000) {
237 /* if we dont use msr EE it means we are desktop CPU (with exeception
239 } else if (tjmax
== 100000) {
240 dev_warn(dev
, "Using relative temperature scale!\n");
246 static int __devinit
get_tjmax(struct cpuinfo_x86
*c
, u32 id
,
249 /* The 100C is default for both mobile and non mobile CPUs */
254 /* A new feature of current Intel(R) processors, the
255 IA32_TEMPERATURE_TARGET contains the TjMax value */
256 err
= rdmsr_safe_on_cpu(id
, MSR_IA32_TEMPERATURE_TARGET
, &eax
, &edx
);
258 dev_warn(dev
, "Unable to read TjMax from CPU.\n");
260 val
= (eax
>> 16) & 0xff;
262 * If the TjMax is not plausible, an assumption
265 if ((val
> 80) && (val
< 120)) {
266 dev_info(dev
, "TjMax is %d C.\n", val
);
272 * An assumption is made for early CPUs and unreadable MSR.
273 * NOTE: the given value may not be correct.
276 switch (c
->x86_model
) {
281 dev_warn(dev
, "TjMax is assumed as 100 C!\n");
285 case 0x1c: /* Atom CPUs */
286 return adjust_tjmax(c
, id
, dev
);
289 dev_warn(dev
, "CPU (model=0x%x) is not supported yet,"
290 " using default TjMax of 100C.\n", c
->x86_model
);
295 static int __devinit
coretemp_probe(struct platform_device
*pdev
)
297 struct coretemp_data
*data
;
298 struct cpuinfo_x86
*c
= &cpu_data(pdev
->id
);
302 if (!(data
= kzalloc(sizeof(struct coretemp_data
), GFP_KERNEL
))) {
304 dev_err(&pdev
->dev
, "Out of memory\n");
310 data
->core_id
= c
->cpu_core_id
;
312 data
->name
= "coretemp";
313 mutex_init(&data
->update_lock
);
315 /* test if we can access the THERM_STATUS MSR */
316 err
= rdmsr_safe_on_cpu(data
->id
, MSR_IA32_THERM_STATUS
, &eax
, &edx
);
319 "Unable to access THERM_STATUS MSR, giving up\n");
323 /* Check if we have problem with errata AE18 of Core processors:
324 Readings might stop update when processor visited too deep sleep,
325 fixed for stepping D0 (6EC).
328 if ((c
->x86_model
== 0xe) && (c
->x86_mask
< 0xc)) {
329 /* check for microcode update */
330 rdmsr_on_cpu(data
->id
, MSR_IA32_UCODE_REV
, &eax
, &edx
);
334 "Errata AE18 not fixed, update BIOS or "
335 "microcode of the CPU!\n");
340 data
->tjmax
= get_tjmax(c
, data
->id
, &pdev
->dev
);
341 platform_set_drvdata(pdev
, data
);
344 * read the still undocumented IA32_TEMPERATURE_TARGET. It exists
345 * on older CPUs but not in this register,
346 * Atoms don't have it either.
349 if ((c
->x86_model
> 0xe) && (c
->x86_model
!= 0x1c)) {
350 err
= rdmsr_safe_on_cpu(data
->id
, MSR_IA32_TEMPERATURE_TARGET
,
353 dev_warn(&pdev
->dev
, "Unable to read"
354 " IA32_TEMPERATURE_TARGET MSR\n");
356 data
->ttarget
= data
->tjmax
-
357 (((eax
>> 8) & 0xff) * 1000);
358 err
= device_create_file(&pdev
->dev
,
359 &sensor_dev_attr_temp1_max
.dev_attr
);
365 if ((err
= sysfs_create_group(&pdev
->dev
.kobj
, &coretemp_group
)))
368 data
->hwmon_dev
= hwmon_device_register(&pdev
->dev
);
369 if (IS_ERR(data
->hwmon_dev
)) {
370 err
= PTR_ERR(data
->hwmon_dev
);
371 dev_err(&pdev
->dev
, "Class registration failed (%d)\n",
379 sysfs_remove_group(&pdev
->dev
.kobj
, &coretemp_group
);
381 device_remove_file(&pdev
->dev
, &sensor_dev_attr_temp1_max
.dev_attr
);
388 static int __devexit
coretemp_remove(struct platform_device
*pdev
)
390 struct coretemp_data
*data
= platform_get_drvdata(pdev
);
392 hwmon_device_unregister(data
->hwmon_dev
);
393 sysfs_remove_group(&pdev
->dev
.kobj
, &coretemp_group
);
394 device_remove_file(&pdev
->dev
, &sensor_dev_attr_temp1_max
.dev_attr
);
395 platform_set_drvdata(pdev
, NULL
);
400 static struct platform_driver coretemp_driver
= {
402 .owner
= THIS_MODULE
,
405 .probe
= coretemp_probe
,
406 .remove
= __devexit_p(coretemp_remove
),
410 struct list_head list
;
411 struct platform_device
*pdev
;
419 static LIST_HEAD(pdev_list
);
420 static DEFINE_MUTEX(pdev_list_mutex
);
422 static int __cpuinit
coretemp_device_add(unsigned int cpu
)
425 struct platform_device
*pdev
;
426 struct pdev_entry
*pdev_entry
;
427 struct cpuinfo_x86
*c
= &cpu_data(cpu
);
430 * CPUID.06H.EAX[0] indicates whether the CPU has thermal
431 * sensors. We check this bit only, all the early CPUs
432 * without thermal sensors will be filtered out.
434 if (!cpu_has(c
, X86_FEATURE_DTS
)) {
435 printk(KERN_INFO DRVNAME
": CPU (model=0x%x)"
436 " has no thermal sensor.\n", c
->x86_model
);
440 mutex_lock(&pdev_list_mutex
);
443 /* Skip second HT entry of each core */
444 list_for_each_entry(pdev_entry
, &pdev_list
, list
) {
445 if (c
->phys_proc_id
== pdev_entry
->phys_proc_id
&&
446 c
->cpu_core_id
== pdev_entry
->cpu_core_id
) {
447 err
= 0; /* Not an error */
453 pdev
= platform_device_alloc(DRVNAME
, cpu
);
456 printk(KERN_ERR DRVNAME
": Device allocation failed\n");
460 pdev_entry
= kzalloc(sizeof(struct pdev_entry
), GFP_KERNEL
);
463 goto exit_device_put
;
466 err
= platform_device_add(pdev
);
468 printk(KERN_ERR DRVNAME
": Device addition failed (%d)\n",
470 goto exit_device_free
;
473 pdev_entry
->pdev
= pdev
;
474 pdev_entry
->cpu
= cpu
;
476 pdev_entry
->phys_proc_id
= c
->phys_proc_id
;
477 pdev_entry
->cpu_core_id
= c
->cpu_core_id
;
479 list_add_tail(&pdev_entry
->list
, &pdev_list
);
480 mutex_unlock(&pdev_list_mutex
);
487 platform_device_put(pdev
);
489 mutex_unlock(&pdev_list_mutex
);
493 static void coretemp_device_remove(unsigned int cpu
)
495 struct pdev_entry
*p
;
498 mutex_lock(&pdev_list_mutex
);
499 list_for_each_entry(p
, &pdev_list
, list
) {
503 platform_device_unregister(p
->pdev
);
505 mutex_unlock(&pdev_list_mutex
);
507 for_each_cpu(i
, cpu_sibling_mask(cpu
))
508 if (i
!= cpu
&& !coretemp_device_add(i
))
512 mutex_unlock(&pdev_list_mutex
);
515 static int __cpuinit
coretemp_cpu_callback(struct notifier_block
*nfb
,
516 unsigned long action
, void *hcpu
)
518 unsigned int cpu
= (unsigned long) hcpu
;
522 case CPU_DOWN_FAILED
:
523 coretemp_device_add(cpu
);
525 case CPU_DOWN_PREPARE
:
526 coretemp_device_remove(cpu
);
532 static struct notifier_block coretemp_cpu_notifier __refdata
= {
533 .notifier_call
= coretemp_cpu_callback
,
536 static int __init
coretemp_init(void)
538 int i
, err
= -ENODEV
;
540 /* quick check if we run Intel */
541 if (cpu_data(0).x86_vendor
!= X86_VENDOR_INTEL
)
544 err
= platform_driver_register(&coretemp_driver
);
548 for_each_online_cpu(i
)
549 coretemp_device_add(i
);
551 #ifndef CONFIG_HOTPLUG_CPU
552 if (list_empty(&pdev_list
)) {
554 goto exit_driver_unreg
;
558 register_hotcpu_notifier(&coretemp_cpu_notifier
);
561 #ifndef CONFIG_HOTPLUG_CPU
563 platform_driver_unregister(&coretemp_driver
);
569 static void __exit
coretemp_exit(void)
571 struct pdev_entry
*p
, *n
;
572 #ifdef CONFIG_HOTPLUG_CPU
573 unregister_hotcpu_notifier(&coretemp_cpu_notifier
);
575 mutex_lock(&pdev_list_mutex
);
576 list_for_each_entry_safe(p
, n
, &pdev_list
, list
) {
577 platform_device_unregister(p
->pdev
);
581 mutex_unlock(&pdev_list_mutex
);
582 platform_driver_unregister(&coretemp_driver
);
585 MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>");
586 MODULE_DESCRIPTION("Intel Core temperature monitor");
587 MODULE_LICENSE("GPL");
589 module_init(coretemp_init
)
590 module_exit(coretemp_exit
)