[PATCH 08/15] hwmon, fam15h_power: add max compute unit accumulated power

[Huang Rui <ray.huang@amd.com>]

This patch adds a member in fam15h_power_data which specifies the
maximum accumulated power in a compute unit.

Signed-off-by: Huang Rui <ray.huang@amd.com>
---
 drivers/hwmon/fam15h_power.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/hwmon/fam15h_power.c b/drivers/hwmon/fam15h_power.c
index d6efcf6..fdfa18e 100644
--- a/drivers/hwmon/fam15h_power.c
+++ b/drivers/hwmon/fam15h_power.c
@@ -26,6 +26,7 @@
 #include <linux/pci.h>
 #include <linux/bitops.h>
 #include <asm/processor.h>
+#include <asm/msr.h>
 
 MODULE_DESCRIPTION("AMD Family 15h CPU processor power monitor");
 MODULE_AUTHOR("Andreas Herrmann <herrmann.der.user@googlemail.com>");
@@ -43,12 +44,16 @@ MODULE_LICENSE("GPL");
 
 #define FAM15H_MIN_POWER_GROUPS		2
 
+#define MSR_F15H_CU_MAX_PWR_ACCUMULATOR	0xc001007b
+
 struct fam15h_power_data {
 	struct pci_dev *pdev;
 	unsigned int tdp_to_watts;
 	unsigned int base_tdp;
 	unsigned int processor_pwr_watts;
 	unsigned int cpu_pwr_sample_ratio;
+	/* maximum accumulated power of a compute unit */
+	u64 max_cu_acc_power;
 };
 
 static ssize_t show_power(struct device *dev,
@@ -199,8 +204,8 @@ static int fam15h_power_resume(struct pci_dev *pdev)
 #define fam15h_power_resume NULL
 #endif
 
-static void fam15h_power_init_data(struct pci_dev *f4,
-					     struct fam15h_power_data *data)
+static int fam15h_power_init_data(struct pci_dev *f4,
+				  struct fam15h_power_data *data)
 {
 	u32 val, eax, ebx, ecx, edx;
 	u64 tmp;
@@ -228,7 +233,7 @@ static void fam15h_power_init_data(struct pci_dev *f4,
 
 	/* CPUID Fn8000_0007:EDX[12] indicates to support accumulated power */
 	if (!(edx & BIT(12)))
-		return;
+		return 0;
 
 	/*
 	 * detemine the ratio of the compute unit power accumulator
@@ -236,6 +241,15 @@ static void fam15h_power_init_data(struct pci_dev *f4,
 	 * Fn8000_0007:ECX
 	 */
 	data->cpu_pwr_sample_ratio = ecx;
+
+	if (rdmsrl_safe(MSR_F15H_CU_MAX_PWR_ACCUMULATOR, &tmp)) {
+		pr_err("Failed to read max compute unit power accumulator MSR\n");
+		return -ENODEV;
+	}
+
+	data->max_cu_acc_power = tmp;
+
+	return 0;
 }
 
 static int fam15h_power_probe(struct pci_dev *pdev,
@@ -262,7 +276,9 @@ static int fam15h_power_probe(struct pci_dev *pdev,
 	if (fam15h_power_init_attrs(pdev))
 		return -ENOMEM;
 
-	fam15h_power_init_data(pdev, data);
+	if (fam15h_power_init_data(pdev, data))
+		return -ENODEV;
+
 	data->pdev = pdev;
 
 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, "fam15h_power",
-- 
1.9.1