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path: root/drivers/hwmon/coretemp.c
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Diffstat (limited to 'drivers/hwmon/coretemp.c')
-rw-r--r--drivers/hwmon/coretemp.c93
1 files changed, 69 insertions, 24 deletions
diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
index e9b7fbc5a447..2988da150ed6 100644
--- a/drivers/hwmon/coretemp.c
+++ b/drivers/hwmon/coretemp.c
@@ -241,6 +241,55 @@ static int __devinit adjust_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *
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;
@@ -283,14 +332,18 @@ static int __devinit coretemp_probe(struct platform_device *pdev)
}
}
- data->tjmax = adjust_tjmax(c, data->id, &pdev->dev);
+ 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 */
+ /*
+ * 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, 0x1a2, &eax, &edx);
+ 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");
@@ -451,28 +504,20 @@ static int __init coretemp_init(void)
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;
- /* check if family 6, models 0xe (Pentium M DC),
- 0xf (Core 2 DC 65nm), 0x16 (Core 2 SC 65nm),
- 0x17 (Penryn 45nm), 0x1a (Nehalem), 0x1c (Atom),
- 0x1e (Lynnfield) */
- if ((c->cpuid_level < 0) || (c->x86 != 0x6) ||
- !((c->x86_model == 0xe) || (c->x86_model == 0xf) ||
- (c->x86_model == 0x16) || (c->x86_model == 0x17) ||
- (c->x86_model == 0x1a) || (c->x86_model == 0x1c) ||
- (c->x86_model == 0x1e))) {
-
- /* supported CPU not found, but report the unknown
- family 6 CPU */
- if ((c->x86 == 0x6) && (c->x86_model > 0xf))
- printk(KERN_WARNING DRVNAME ": Unknown CPU "
- "model 0x%x\n", c->x86_model);
- continue;
+ } else {
+ printk(KERN_INFO DRVNAME ": CPU (model=0x%x)"
+ " has no thermal sensor.\n", c->x86_model);
}
-
- err = coretemp_device_add(i);
- if (err)
- goto exit_devices_unreg;
}
if (list_empty(&pdev_list)) {
err = -ENODEV;