/*
* coretemp.c - Linux kernel module for hardware monitoring
*
* Copyright (C) 2007 Rudolf Marek <r.marek@assembler.cz>
*
* Inspired from many hwmon drivers
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA.
*/
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/hwmon.h>
#include <linux/sysfs.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/platform_device.h>
#include <linux/cpu.h>
#include <linux/pci.h>
#include <asm/msr.h>
#include <asm/processor.h>
#define DRVNAME "coretemp"
typedef enum { SHOW_TEMP, SHOW_TJMAX, SHOW_TTARGET, SHOW_LABEL,
SHOW_NAME } SHOW;
/*
* Functions declaration
*/
static struct coretemp_data *coretemp_update_device(struct device *dev);
struct coretemp_data {
struct device *hwmon_dev;
struct mutex update_lock;
const char *name;
u32 id;
char valid; /* zero until following fields are valid */
unsigned long last_updated; /* in jiffies */
int temp;
int tjmax;
int ttarget;
u8 alarm;
};
/*
* Sysfs stuff
*/
static ssize_t show_name(struct device *dev, struct device_attribute
*devattr, char *buf)
{
int ret;
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
struct coretemp_data *data = dev_get_drvdata(dev);
if (attr->index == SHOW_NAME)
ret = sprintf(buf, "%s\n", data->name);
else /* show label */
ret = sprintf(buf, "Core %d\n", data->id);
return ret;
}
static ssize_t show_alarm(struct device *dev, struct device_attribute
*devattr, char *buf)
{
struct coretemp_data *data = coretemp_update_device(dev);
/* read the Out-of-spec log, never clear */
return sprintf(buf, "%d\n", data->alarm);
}
static ssize_t show_temp(struct device *dev,
struct device_attribute *devattr, char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
struct coretemp_data *data = coretemp_update_device(dev);
int err;
if (attr->index == SHOW_TEMP)
err = data->valid ? sprintf(buf, "%d\n", data->temp) : -EAGAIN;
else if (attr->index == SHOW_TJMAX)
err = sprintf(buf, "%d\n", data->tjmax);
else
err = sprintf(buf, "%d\n", data->ttarget);
return err;
}
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL,
SHOW_TEMP);
static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL,
SHOW_TJMAX);
static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL,
SHOW_TTARGET);
static DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL);
static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_name, NULL, SHOW_LABEL);
static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, SHOW_NAME);
static struct attribute *coretemp_attributes[] = {
&sensor_dev_attr_name.dev_attr.attr,
&sensor_dev_attr_temp1_label.dev_attr.attr,
&dev_attr_temp1_crit_alarm.attr,
&sensor_dev_attr_temp1_input.dev_attr.attr,
&sensor_dev_attr_temp1_crit.dev_attr.attr,
NULL
};
static const struct attribute_group coretemp_group = {
.attrs = coretemp_attributes,
};
static struct coretemp_data *coretemp_update_device(struct device *dev)
{
struct coretemp_data *data = dev_get_drvdata(dev);
mutex_lock(&data->update_lock);
if (!data->valid || time_after(jiffies, data->last_updated + HZ)) {
u32 eax, edx;
data->valid = 0;
rdmsr_on_cpu(data->id, MSR_IA32_THERM_STATUS, &eax, &edx);
data->alarm = (eax >> 5) & 1;
/* update only if data has been valid */
if (eax & 0x80000000) {
data->temp = data->tjmax - (((eax >> 16)
& 0x7f) * 1000);
data->valid = 1;
} else {
dev_dbg(dev, "Temperature data invalid (0x%x)\n", eax);
}
data->last_updated = jiffies;
}
mutex_unlock(&data->update_lock);
return data;
}
static int __devinit adjust_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *dev)
{
/* The 100C is default for both mobile and non mobile CPUs */
int tjmax = 100000;
int tjmax_ee = 85000;
int usemsr_ee = 1;
int err;
u32 eax, edx;
struct pci_dev *host_bridge;
/* Early chips have no MSR for TjMax */
if ((c->x86_model == 0xf) && (c->x86_mask < 4)) {
usemsr_ee = 0;
}
/* Atom CPUs */
if (c->x86_model == 0x1c) {
usemsr_ee = 0;
host_bridge = pci_get_bus_and_slot(0, PCI_DEVFN(0, 0));
if (host_bridge && host_bridge->vendor == PCI_VENDOR_ID_INTEL
&& (host_bridge->device == 0xa000 /* NM10 based nettop */
|| host_bridge->device == 0xa010)) /* NM10 based netbook */
tjmax = 100000;
else
tjmax = 90000;
pci_dev_put(host_bridge);
}
if ((c->x86_model > 0xe) && (usemsr_ee)) {
u8 platform_id;
/* Now we can detect the mobile CPU using Intel provided table
http://softwarecommunity.intel.com/Wiki/Mobility/720.htm
For Core2 cores, check MSR 0x17, bit 28 1 = Mobile CPU
*/
err = rdmsr_safe_on_cpu(id, 0x17, &eax, &edx);
if (err) {
dev_warn(dev,
"Unable to access MSR 0x17, assuming desktop"
" CPU\n");
usemsr_ee = 0;
} else if (c->x86_model < 0x17 && !(eax & 0x10000000)) {
/* Trust bit 28 up to Penryn, I could not find any
documentation on that; if you happen to know
someone at Intel please ask */
usemsr_ee = 0;
} else {
/* Platform ID bits 52:50 (EDX starts at bit 32) */
platform_id = (edx >> 18) & 0x7;
/* Mobile Penryn CPU seems to be platform ID 7 or 5
(guesswork) */
if ((c->x86_model == 0x17) &&
((platform_id == 5) || (platform_id == 7))) {
/* If MSR EE bit is set, set it to 90 degrees C,
otherwise 105 degrees C */
tjmax_ee = 90000;
tjmax = 105000;
}
}
}
if (usemsr_ee) {
err = rdmsr_safe_on_cpu(id, 0xee, &eax, &edx);
if (err) {
dev_warn(dev,
"Unable to access MSR 0xEE, for Tjmax, left"
" at default\n");
} else if (eax & 0x40000000) {
tjmax = tjmax_ee;
}
/* if we dont use msr EE it means we are desktop CPU (with exeception
of Atom) */
} else if (tjmax == 100000) {
dev_warn(dev, "Using relative temperature scale!\n");
}
return tjmax;
}
static int __devinit get_tjmax(struct cpuinfo_x86 *c, u32 id,
struct device *dev)
{
/* The 100C is default for both mobile and non mobile CPUs */
int err;
u32 eax, edx;
u32 val;
/* A new feature of current Intel(R) processors, the
IA32_TEMPERATURE_TARGET contains the TjMax value */
err = rdmsr_safe_on_cpu(id, MSR_IA32_TEMPERATURE_TARGET, &eax, &edx);
if (err) {
dev_warn(dev, "Unable to read TjMax from CPU.\n");
} else {
val = (eax >> 16) & 0xff;
/*
* If the TjMax is not plausible, an assumption
* will be used
*/
if ((val > 80) && (val < 120)) {
dev_info(dev, "TjMax is %d C.\n", val);
return val * 1000;
}
}
/*
* An assumption is made for early CPUs and unreadable MSR.
* NOTE: the given value may not be correct.
*/
switch (c->x86_model) {
case 0xe:
case 0xf:
case 0x16:
case 0x1a:
dev_warn(dev, "TjMax is assumed as 100 C!\n");
return 100000;
break;
case 0x17:
case 0x1c: /* Atom CPUs */
return adjust_tjmax(c, id, dev);
break;
default:
dev_warn(dev, "CPU (model=0x%x) is not supported yet,"
" using default TjMax of 100C.\n", c->x86_model);
return 100000;
}
}
static int __devinit coretemp_probe(struct platform_device *pdev)
{
struct coretemp_data *data;
struct cpuinfo_x86 *c = &cpu_data(pdev->id);
int err;
u32 eax, edx;
if (!(data = kzalloc(sizeof(struct coretemp_data), GFP_KERNEL))) {
err = -ENOMEM;
dev_err(&pdev->dev, "Out of memory\n");
goto exit;
}
data->id = pdev->id;
data->name = "coretemp";
mutex_init(&data->update_lock);
/* test if we can access the THERM_STATUS MSR */
err = rdmsr_safe_on_cpu(data->id, MSR_IA32_THERM_STATUS, &eax, &edx);
if (err) {
dev_err(&pdev->dev,
"Unable to access THERM_STATUS MSR, giving up\n");
goto exit_free;
}
/* Check if we have problem with errata AE18 of Core processors:
Readings might stop update when processor visited too deep sleep,
fixed for stepping D0 (6EC).
*/
if ((c->x86_model == 0xe) && (c->x86_mask < 0xc)) {
/* check for microcode update */
rdmsr_on_cpu(data->id, MSR_IA32_UCODE_REV, &eax, &edx);
if (edx < 0x39) {
err = -ENODEV;
dev_err(&pdev->dev,
"Errata AE18 not fixed, update BIOS or "
"microcode of the CPU!\n");
goto exit_free;
}
}
data->tjmax = get_tjmax(c, data->id, &pdev->dev);
platform_set_drvdata(pdev, data);
/*
* read the still undocumented IA32_TEMPERATURE_TARGET. It exists
* on older CPUs but not in this register,
* Atoms don't have it either.
*/
if ((c->x86_model > 0xe) && (c->x86_model != 0x1c)) {
err = rdmsr_safe_on_cpu(data->id, MSR_IA32_TEMPERATURE_TARGET,
&eax, &edx);
if (err) {
dev_warn(&pdev->dev, "Unable to read"
" IA32_TEMPERATURE_TARGET MSR\n");
} else {
data->ttarget = data->tjmax -
(((eax >> 8) & 0xff) * 1000);
err = device_create_file(&pdev->dev,
&sensor_dev_attr_temp1_max.dev_attr);
if (err)
goto exit_free;
}
}
if ((err = sysfs_create_group(&pdev->dev.kobj, &coretemp_group)))
goto exit_dev;
data->hwmon_dev = hwmon_device_register(&pdev->dev);
if (IS_ERR(data->hwmon_dev)) {
err = PTR_ERR(data->hwmon_dev);
dev_err(&pdev->dev, "Class registration failed (%d)\n",
err);
goto exit_class;
}
return 0;
exit_class:
sysfs_remove_group(&pdev->dev.kobj, &coretemp_group);
exit_dev:
device_remove_file(&pdev->dev, &sensor_dev_attr_temp1_max.dev_attr);
exit_free:
kfree(data);
exit:
return err;
}
static int __devexit coretemp_remove(struct platform_device *pdev)
{
struct coretemp_data *data = platform_get_drvdata(pdev);
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&pdev->dev.kobj, &coretemp_group);
device_remove_file(&pdev->dev, &sensor_dev_attr_temp1_max.dev_attr);
platform_set_drvdata(pdev, NULL);
kfree(data);
return 0;
}
static struct platform_driver coretemp_driver = {
.driver = {
.owner = THIS_MODULE,
.name = DRVNAME,
},
.probe = coretemp_probe,
.remove = __devexit_p(coretemp_remove),
};
struct pdev_entry {
struct list_head list;
struct platform_device *pdev;
unsigned int cpu;
};
static LIST_HEAD(pdev_list);
static DEFINE_MUTEX(pdev_list_mutex);
static int __cpuinit coretemp_device_add(unsigned int cpu)
{
int err;
struct platform_device *pdev;
struct pdev_entry *pdev_entry;
pdev = platform_device_alloc(DRVNAME, cpu);
if (!pdev) {
err = -ENOMEM;
printk(KERN_ERR DRVNAME ": Device allocation failed\n");
goto exit;
}
pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
if (!pdev_entry) {
err = -ENOMEM;
goto exit_device_put;
}
err = platform_device_add(pdev);
if (err) {
printk(KERN_ERR DRVNAME ": Device addition failed (%d)\n",
err);
goto exit_device_free;
}
pdev_entry->pdev = pdev;
pdev_entry->cpu = cpu;
mutex_lock(&pdev_list_mutex);
list_add_tail(&pdev_entry->list, &pdev_list);
mutex_unlock(&pdev_list_mutex);
return 0;
exit_device_free:
kfree(pdev_entry);
exit_device_put:
platform_device_put(pdev);
exit:
return err;
}
#ifdef CONFIG_HOTPLUG_CPU
static void coretemp_device_remove(unsigned int cpu)
{
struct pdev_entry *p, *n;
mutex_lock(&pdev_list_mutex);
list_for_each_entry_safe(p, n, &pdev_list, list) {
if (p->cpu == cpu) {
platform_device_unregister(p->pdev);
list_del(&p->list);
kfree(p);
}
}
mutex_unlock(&pdev_list_mutex);
}
static int __cpuinit coretemp_cpu_callback(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned long) hcpu;
switch (action) {
case CPU_ONLINE:
case CPU_DOWN_FAILED:
coretemp_device_add(cpu);
break;
case CPU_DOWN_PREPARE:
coretemp_device_remove(cpu);
break;
}
return NOTIFY_OK;
}
static struct notifier_block coretemp_cpu_notifier __refdata = {
.notifier_call = coretemp_cpu_callback,
};
#endif /* !CONFIG_HOTPLUG_CPU */
static int __init coretemp_init(void)
{
int i, err = -ENODEV;
struct pdev_entry *p, *n;
/* quick check if we run Intel */
if (cpu_data(0).x86_vendor != X86_VENDOR_INTEL)
goto exit;
err = platform_driver_register(&coretemp_driver);
if (err)
goto exit;
for_each_online_cpu(i) {
struct cpuinfo_x86 *c = &cpu_data(i);
/*
* CPUID.06H.EAX[0] indicates whether the CPU has thermal
* sensors. We check this bit only, all the early CPUs
* without thermal sensors will be filtered out.
*/
if (c->cpuid_level >= 6 && (cpuid_eax(0x06) & 0x01)) {
err = coretemp_device_add(i);
if (err)
goto exit_devices_unreg;
} else {
printk(KERN_INFO DRVNAME ": CPU (model=0x%x)"
" has no thermal sensor.\n", c->x86_model);
}
}
if (list_empty(&pdev_list)) {
err = -ENODEV;
goto exit_driver_unreg;
}
#ifdef CONFIG_HOTPLUG_CPU
register_hotcpu_notifier(&coretemp_cpu_notifier);
#endif
return 0;
exit_devices_unreg:
mutex_lock(&pdev_list_mutex);
list_for_each_entry_safe(p, n, &pdev_list, list) {
platform_device_unregister(p->pdev);
list_del(&p->list);
kfree(p);
}
mutex_unlock(&pdev_list_mutex);
exit_driver_unreg:
platform_driver_unregister(&coretemp_driver);
exit:
return err;
}
static void __exit coretemp_exit(void)
{
struct pdev_entry *p, *n;
#ifdef CONFIG_HOTPLUG_CPU
unregister_hotcpu_notifier(&coretemp_cpu_notifier);
#endif
mutex_lock(&pdev_list_mutex);
list_for_each_entry_safe(p, n, &pdev_list, list) {
platform_device_unregister(p->pdev);
list_del(&p->list);
kfree(p);
}
mutex_unlock(&pdev_list_mutex);
platform_driver_unregister(&coretemp_driver);
}
MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>");
MODULE_DESCRIPTION("Intel Core temperature monitor");
MODULE_LICENSE("GPL");
module_init(coretemp_init)
module_exit(coretemp_exit)
