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;