[PATCH 07/15] hwmon, fam15h_power: add ratio of Tsample to the PTSC period

Huang Rui
2015-08-27T08:25:11Z

This patch adds a member (cpu_pwr_sample_ratio) of fam15h_power_data,
that represents the ratio of compute unit power accumulator sample
period to the PTSC counter period.

Tsample: compute unit power accumulator sample period
Tref: the performance timestamp counter period
PTSC: performance timestamp counter

Signed-off-by: Huang Rui <ray.huang@amd.com>
---
drivers/hwmon/fam15h_power.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/fam15h_power.c b/drivers/hwmon/fam15h_power.c
index 55b25ef..d6efcf6 100644
--- a/drivers/hwmon/fam15h_power.c
+++ b/drivers/hwmon/fam15h_power.c
@@ -48,6 +48,7 @@ struct fam15h_power_data {
unsigned int tdp_to_watts;
unsigned int base_tdp;
unsigned int processor_pwr_watts;
+ unsigned int cpu_pwr_sample_ratio;
};

static ssize_t show_power(struct device *dev,
@@ -201,7 +202,7 @@ static int fam15h_power_resume(struct pci_dev *pdev)
static void fam15h_power_init_data(struct pci_dev *f4,
struct fam15h_power_data *data)
{
- u32 val;
+ u32 val, eax, ebx, ecx, edx;
u64 tmp;

pci_read_config_dword(f4, REG_PROCESSOR_TDP, &val);
@@ -222,6 +223,19 @@ static void fam15h_power_init_data(struct pci_dev *f4,

/* convert to microWatt */
data->processor_pwr_watts = (tmp * 15625) >> 10;
+
+ cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
+
+ /* CPUID Fn8000_0007:EDX[12] indicates to support accumulated power */
+ if (!(edx & BIT(12)))
+ return;
+
+ /*
+ * detemine the ratio of the compute unit power accumulator
+ * sample period to the PTSC counter period by executing CPUID
+ * Fn8000_0007:ECX
+ */
+ data->cpu_pwr_sample_ratio = ecx;
}

static int fam15h_power_probe(struct pci_dev *pdev,
--
1.9.1