hwmon: (k10temp) Blacklist more family 10h processors

The latest version of the Revision Guide for AMD Family 10h Processors
lists two more processor revisions which may be affected by erratum 319.
Change the blacklisting code to correctly detect those processors, by
implementing AMD's recommended algorithm.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Andreas Herrmann <herrmann.der.user@googlemail.com>

1 files changed, 32 insertions, 6 deletions

diff --git a/drivers/hwmon/k10temp.c b/drivers/hwmon/k10temp.c
index d8a26d1..4c9d349 100644
--- a/drivers/hwmon/k10temp.c
+++ b/drivers/hwmon/k10temp.c
@@ -33,6 +33,16 @@ static bool force;
 module_param(force, bool, 0444);
 MODULE_PARM_DESC(force, "force loading on processors with erratum 319");
 
+/* CPUID function 0x80000001, ebx */
+#define CPUID_PKGTYPE_MASK	0xf0000000
+#define CPUID_PKGTYPE_F		0x00000000
+#define CPUID_PKGTYPE_AM2R2_AM3	0x10000000
+
+/* DRAM controller (PCI function 2) */
+#define REG_DCT0_CONFIG_HIGH		0x094
+#define  DDR3_MODE			0x00000100
+
+/* miscellaneous (PCI function 3) */
 #define REG_HARDWARE_THERMAL_CONTROL	0x64
 #define  HTC_ENABLE			0x00000001
 
@@ -85,13 +95,28 @@ static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp_crit, NULL, 0);
 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO, show_temp_crit, NULL, 1);
 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
 
-static bool __devinit has_erratum_319(void)
+static bool __devinit has_erratum_319(struct pci_dev *pdev)
 {
+	u32 pkg_type, reg_dram_cfg;
+
+	if (boot_cpu_data.x86 != 0x10)
+		return false;
+
 	/*
-	 * Erratum 319: The thermal sensor of older Family 10h processors
-	 *              (B steppings) may be unreliable.
+	 * Erratum 319: The thermal sensor of Socket F/AM2+ processors
+	 *              may be unreliable.
 	 */
-	return boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model <= 2;
+	pkg_type = cpuid_ebx(0x80000001) & CPUID_PKGTYPE_MASK;
+	if (pkg_type == CPUID_PKGTYPE_F)
+		return true;
+	if (pkg_type != CPUID_PKGTYPE_AM2R2_AM3)
+		return false;
+
+	/* Differentiate between AM2+ (bad) and AM3 (good) */
+	pci_bus_read_config_dword(pdev->bus,
+				  PCI_DEVFN(PCI_SLOT(pdev->devfn), 2),
+				  REG_DCT0_CONFIG_HIGH, &reg_dram_cfg);
+	return !(reg_dram_cfg & DDR3_MODE);
 }
 
 static int __devinit k10temp_probe(struct pci_dev *pdev,
@@ -99,9 +124,10 @@ static int __devinit k10temp_probe(struct pci_dev *pdev,
 {
 	struct device *hwmon_dev;
 	u32 reg_caps, reg_htc;
+	int unreliable = has_erratum_319(pdev);
 	int err;
 
-	if (has_erratum_319() && !force) {
+	if (unreliable && !force) {
 		dev_err(&pdev->dev,
 			"unreliable CPU thermal sensor; monitoring disabled\n");
 		err = -ENODEV;
@@ -139,7 +165,7 @@ static int __devinit k10temp_probe(struct pci_dev *pdev,
 	}
 	dev_set_drvdata(&pdev->dev, hwmon_dev);
 
-	if (has_erratum_319() && force)
+	if (unreliable && force)
 		dev_warn(&pdev->dev,
 			 "unreliable CPU thermal sensor; check erratum 319\n");
 	return 0;