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hwmon: (fam15h_power) Introduce a cpu accumulated power reporting algorithm 

This patch introduces an algorithm that computes the average power by
reading a delta value of “core power accumulator” register during
measurement interval, and then dividing delta value by the length of
the time interval.

User is able to use power1_average entry to measure the processor power
consumption and power1_average_interval entry to set the interval.

A simple example:

ray@hr-ub:~/tip$ sensors
fam15h_power-pci-00c4
Adapter: PCI adapter
power1:       19.58 mW (avg =   2.55 mW, interval =   0.01 s)
                       (crit =  15.00 W)

...

The result is current average processor power consumption in 10
millisecond. The unit of the result is uWatt.

Suggested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Cc: Borislav Petkov <bp@alien8.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Huang Rui 2016-04-06 15:44:13 +08:00 committed by Guenter Roeck
parent cdb9e110b1
commit 11bf0d78cc
1 changed files with 124 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

128
drivers/hwmon/fam15h_power.c
View File

@ -27,6 +27,8 @@
#include <linux/bitops.h>
#include <linux/cpu.h>
#include <linux/cpumask.h>
#include <linux/time.h>
#include <linux/sched.h>
#include <asm/processor.h>
#include <asm/msr.h>
@ -48,6 +50,9 @@ MODULE_LICENSE("GPL");
#define FAM15H_NUM_GROUPS 2
#define MAX_CUS 8
/* set maximum interval as 1 second */
#define MAX_INTERVAL 1000
#define MSR_F15H_CU_PWR_ACCUMULATOR 0xc001007a
#define MSR_F15H_CU_MAX_PWR_ACCUMULATOR 0xc001007b
#define MSR_F15H_PTSC 0xc0010280
@ -68,6 +73,9 @@ struct fam15h_power_data {
u64 cu_acc_power[MAX_CUS];
/* performance timestamp counter */
u64 cpu_sw_pwr_ptsc[MAX_CUS];
/* online/offline status of current compute unit */
int cu_on[MAX_CUS];
unsigned long power_period;
};
static ssize_t show_power(struct device *dev,
@ -149,6 +157,8 @@ static void do_read_registers_on_cu(void *_data)
rdmsrl_safe(MSR_F15H_CU_PWR_ACCUMULATOR, &data->cu_acc_power[cu]);
rdmsrl_safe(MSR_F15H_PTSC, &data->cpu_sw_pwr_ptsc[cu]);
data->cu_on[cu] = 1;
}
/*
@ -165,6 +175,8 @@ static int read_registers(struct fam15h_power_data *data)
if (!ret)
return -ENOMEM;
memset(data->cu_on, 0, sizeof(int) * MAX_CUS);
get_online_cpus();
this_cpu = smp_processor_id();
@ -199,6 +211,98 @@ static int read_registers(struct fam15h_power_data *data)
return 0;
}
static ssize_t acc_show_power(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct fam15h_power_data *data = dev_get_drvdata(dev);
u64 prev_cu_acc_power[MAX_CUS], prev_ptsc[MAX_CUS],
jdelta[MAX_CUS];
u64 tdelta, avg_acc;
int cu, cu_num, ret;
signed long leftover;
/*
* With the new x86 topology modelling, x86_max_cores is the
* compute unit number.
*/
cu_num = boot_cpu_data.x86_max_cores;
ret = read_registers(data);
if (ret)
return 0;
for (cu = 0; cu < cu_num; cu++) {
prev_cu_acc_power[cu] = data->cu_acc_power[cu];
prev_ptsc[cu] = data->cpu_sw_pwr_ptsc[cu];
}
leftover = schedule_timeout_interruptible(msecs_to_jiffies(data->power_period));
if (leftover)
return 0;
ret = read_registers(data);
if (ret)
return 0;
for (cu = 0, avg_acc = 0; cu < cu_num; cu++) {
/* check if current compute unit is online */
if (data->cu_on[cu] == 0)
continue;
if (data->cu_acc_power[cu] < prev_cu_acc_power[cu]) {
jdelta[cu] = data->max_cu_acc_power + data->cu_acc_power[cu];
jdelta[cu] -= prev_cu_acc_power[cu];
} else {
jdelta[cu] = data->cu_acc_power[cu] - prev_cu_acc_power[cu];
}
tdelta = data->cpu_sw_pwr_ptsc[cu] - prev_ptsc[cu];
jdelta[cu] *= data->cpu_pwr_sample_ratio * 1000;
do_div(jdelta[cu], tdelta);
/* the unit is microWatt */
avg_acc += jdelta[cu];
}
return sprintf(buf, "%llu\n", (unsigned long long)avg_acc);
}
static DEVICE_ATTR(power1_average, S_IRUGO, acc_show_power, NULL);
static ssize_t acc_show_power_period(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct fam15h_power_data *data = dev_get_drvdata(dev);
return sprintf(buf, "%lu\n", data->power_period);
}
static ssize_t acc_set_power_period(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct fam15h_power_data *data = dev_get_drvdata(dev);
unsigned long temp;
int ret;
ret = kstrtoul(buf, 10, &temp);
if (ret)
return ret;
if (temp > MAX_INTERVAL)
return -EINVAL;
/* the interval value should be greater than 0 */
if (temp <= 0)
return -EINVAL;
data->power_period = temp;
return count;
}
static DEVICE_ATTR(power1_average_interval, S_IRUGO | S_IWUSR,
acc_show_power_period, acc_set_power_period);
static int fam15h_power_init_attrs(struct pci_dev *pdev,
struct fam15h_power_data *data)
{
@ -211,6 +315,10 @@ static int fam15h_power_init_attrs(struct pci_dev *pdev,
(c->x86_model >= 0x60 && c->x86_model <= 0x7f)))
n += 1;
/* check if processor supports accumulated power */
if (boot_cpu_has(X86_FEATURE_ACC_POWER))
n += 2;
fam15h_power_attrs = devm_kcalloc(&pdev->dev, n,
sizeof(*fam15h_power_attrs),
GFP_KERNEL);
@ -225,6 +333,11 @@ static int fam15h_power_init_attrs(struct pci_dev *pdev,
(c->x86_model >= 0x60 && c->x86_model <= 0x7f)))
fam15h_power_attrs[n++] = &dev_attr_power1_input.attr;
if (boot_cpu_has(X86_FEATURE_ACC_POWER)) {
fam15h_power_attrs[n++] = &dev_attr_power1_average.attr;
fam15h_power_attrs[n++] = &dev_attr_power1_average_interval.attr;
}
data->group.attrs = fam15h_power_attrs;
return 0;
@ -290,7 +403,7 @@ static int fam15h_power_resume(struct pci_dev *pdev)
static int fam15h_power_init_data(struct pci_dev *f4,
struct fam15h_power_data *data)
{
u32 val, eax, ebx, ecx, edx;
u32 val;
u64 tmp;
int ret;
@ -317,10 +430,9 @@ static int fam15h_power_init_data(struct pci_dev *f4,
if (ret)
return ret;
cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
/* CPUID Fn8000_0007:EDX[12] indicates to support accumulated power */
if (!(edx & BIT(12)))
if (!boot_cpu_has(X86_FEATURE_ACC_POWER))
return 0;
/*
@ -328,7 +440,7 @@ static int fam15h_power_init_data(struct pci_dev *f4,
* sample period to the PTSC counter period by executing CPUID
* Fn8000_0007:ECX
*/
data->cpu_pwr_sample_ratio = ecx;
data->cpu_pwr_sample_ratio = cpuid_ecx(0x80000007);
if (rdmsrl_safe(MSR_F15H_CU_MAX_PWR_ACCUMULATOR, &tmp)) {
pr_err("Failed to read max compute unit power accumulator MSR\n");
@ -337,6 +449,14 @@ static int fam15h_power_init_data(struct pci_dev *f4,
data->max_cu_acc_power = tmp;
/*
* Milliseconds are a reasonable interval for the measurement.
* But it shouldn't set too long here, because several seconds
* would cause the read function to hang. So set default
* interval as 10 ms.
*/
data->power_period = 10;
return read_registers(data);
}