On Thu, Jun 27, 2019 at 12:53:38PM +0800, Wu Hao wrote:
> This patch adds support for power management private feature under
> FPGA Management Engine (FME). This private feature driver registers
> a hwmon for power (power1_input), thresholds information, e.g.
> (power1_max / crit / max_alarm / crit_alarm) and also read-only sysfs
> interfaces for other power management information. For configuration,
> user could write threshold values via above power1_max / crit sysfs
> interface under hwmon too.
>
> Signed-off-by: Luwei Kang <luwei.kang@xxxxxxxxx>
> Signed-off-by: Xu Yilun <yilun.xu@xxxxxxxxx>
> Signed-off-by: Wu Hao <hao.wu@xxxxxxxxx>
> ---
> v2: create a dfl_fme_power hwmon to expose power sysfs interfaces.
> move all sysfs interfaces under hwmon
> consumed --> hwmon power1_input
> threshold1 --> hwmon power1_cap
> threshold2 --> hwmon power1_crit
> threshold1_status --> hwmon power1_cap_status
> threshold2_status --> hwmon power1_crit_status
> xeon_limit --> hwmon power1_xeon_limit
> fpga_limit --> hwmon power1_fpga_limit
How do those limits differ from the other limits ?
We do have powerX_cap and powerX_cap_max, and from the context
it appears that you could possibly at least use power1_cap_max
(and power1_cap instead of power1_max) instead of
power1_fpga_limit.
> ltr --> hwmon power1_ltr
> v3: rename some hwmon sysfs interfaces to follow hwmon ABI.
> power1_cap --> power1_max
> power1_cap_status --> power1_max_alarm
> power1_crit_status --> power1_crit_alarm
power1_cap is standard ABI, and since the value is enforced by HW,
it should be usable.
> update sysfs doc for above sysfs interface changes.
> replace scnprintf with sprintf in sysfs interface.
> v4: use HWMON_CHANNEL_INFO.
> update date in sysfs doc.
> ---
> Documentation/ABI/testing/sysfs-platform-dfl-fme | 67 +++++++
> drivers/fpga/dfl-fme-main.c | 221 +++++++++++++++++++++++
> 2 files changed, 288 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-platform-dfl-fme b/Documentation/ABI/testing/sysfs-platform-dfl-fme
> index 2cd17dc..a669548 100644
> --- a/Documentation/ABI/testing/sysfs-platform-dfl-fme
> +++ b/Documentation/ABI/testing/sysfs-platform-dfl-fme
> @@ -127,6 +127,7 @@ Contact: Wu Hao <hao.wu@xxxxxxxxx>
> Description: Read-Only. Read this file to get the name of hwmon device, it
> supports values:
> 'dfl_fme_thermal' - thermal hwmon device name
> + 'dfl_fme_power' - power hwmon device name
>
> What: /sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/temp1_input
> Date: June 2019
> @@ -183,3 +184,69 @@ Description: Read-Only. Read this file to get the policy of hardware threshold1
> (see 'temp1_max'). It only supports two values (policies):
> 0 - AP2 state (90% throttling)
> 1 - AP1 state (50% throttling)
> +
> +What: /sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/power1_input
> +Date: June 2019
> +KernelVersion: 5.3
> +Contact: Wu Hao <hao.wu@xxxxxxxxx>
> +Description: Read-Only. It returns current FPGA power consumption in uW.
> +
> +What: /sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/power1_max
> +Date: June 2019
> +KernelVersion: 5.3
> +Contact: Wu Hao <hao.wu@xxxxxxxxx>
> +Description: Read-Write. Read this file to get current hardware power
> + threshold1 in uW. If power consumption rises at or above
> + this threshold, hardware starts 50% throttling.
> + Write this file to set current hardware power threshold1 in uW.
> + As hardware only accepts values in Watts, so input value will
> + be round down per Watts (< 1 watts part will be discarded).
> + Write fails with -EINVAL if input parsing fails or input isn't
> + in the valid range (0 - 127000000 uW).
> +
> +What: /sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/power1_crit
> +Date: June 2019
> +KernelVersion: 5.3
> +Contact: Wu Hao <hao.wu@xxxxxxxxx>
> +Description: Read-Write. Read this file to get current hardware power
> + threshold2 in uW. If power consumption rises at or above
> + this threshold, hardware starts 90% throttling.
> + Write this file to set current hardware power threshold2 in uW.
> + As hardware only accepts values in Watts, so input value will
> + be round down per Watts (< 1 watts part will be discarded).
> + Write fails with -EINVAL if input parsing fails or input isn't
> + in the valid range (0 - 127000000 uW).
> +
> +What: /sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/power1_max_alarm
> +Date: June 2019
> +KernelVersion: 5.3
> +Contact: Wu Hao <hao.wu@xxxxxxxxx>
> +Description: Read-only. It returns 1 if power consumption is currently at or
> + above hardware threshold1 (see 'power1_max'), otherwise 0.
> +
> +What: /sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/power1_crit_alarm
> +Date: June 2019
> +KernelVersion: 5.3
> +Contact: Wu Hao <hao.wu@xxxxxxxxx>
> +Description: Read-only. It returns 1 if power consumption is currently at or
> + above hardware threshold2 (see 'power1_crit'), otherwise 0.
> +
> +What: /sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/power1_xeon_limit
> +Date: June 2019
> +KernelVersion: 5.3
> +Contact: Wu Hao <hao.wu@xxxxxxxxx>
> +Description: Read-Only. It returns power limit for XEON in uW.
> +
> +What: /sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/power1_fpga_limit
> +Date: June 2019
> +KernelVersion: 5.3
> +Contact: Wu Hao <hao.wu@xxxxxxxxx>
> +Description: Read-Only. It returns power limit for FPGA in uW.
> +
> +What: /sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/power1_ltr
> +Date: June 2019
> +KernelVersion: 5.3
> +Contact: Wu Hao <hao.wu@xxxxxxxxx>
> +Description: Read-only. Read this file to get current Latency Tolerance
> + Reporting (ltr) value. This ltr impacts the CPU low power
> + state in integrated solution.
Does that attribute add any value without any kind of unit or an explanation
of its meaning ? What is userspace supposed to do with that information ?
Without context, it is just a meaningless number.
Also, it appears that the information is supposed to be passed to power
management via the set_latency_tolerance() callback. If so, it would be
reported there. Would it possibly make more sense to use that interface ?
> diff --git a/drivers/fpga/dfl-fme-main.c b/drivers/fpga/dfl-fme-main.c
> index 59ff9f1..9225b68 100644
> --- a/drivers/fpga/dfl-fme-main.c
> +++ b/drivers/fpga/dfl-fme-main.c
> @@ -400,6 +400,223 @@ static void fme_thermal_mgmt_uinit(struct platform_device *pdev,
> .uinit = fme_thermal_mgmt_uinit,
> };
>
> +#define FME_PWR_STATUS 0x8
> +#define FME_LATENCY_TOLERANCE BIT_ULL(18)
> +#define PWR_CONSUMED GENMASK_ULL(17, 0)
> +
> +#define FME_PWR_THRESHOLD 0x10
> +#define PWR_THRESHOLD1 GENMASK_ULL(6, 0) /* in Watts */
> +#define PWR_THRESHOLD2 GENMASK_ULL(14, 8) /* in Watts */
> +#define PWR_THRESHOLD_MAX 0x7f /* in Watts */
> +#define PWR_THRESHOLD1_STATUS BIT_ULL(16)
> +#define PWR_THRESHOLD2_STATUS BIT_ULL(17)
> +
> +#define FME_PWR_XEON_LIMIT 0x18
> +#define XEON_PWR_LIMIT GENMASK_ULL(14, 0) /* in 0.1 Watts */
> +#define XEON_PWR_EN BIT_ULL(15)
> +#define FME_PWR_FPGA_LIMIT 0x20
> +#define FPGA_PWR_LIMIT GENMASK_ULL(14, 0) /* in 0.1 Watts */
> +#define FPGA_PWR_EN BIT_ULL(15)
> +
> +#define PWR_THRESHOLD_MAX_IN_UW (PWR_THRESHOLD_MAX * 1000000)
> +
> +static int power_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
> + u32 attr, int channel, long *val)
> +{
> + struct dfl_feature *feature = dev_get_drvdata(dev);
> + u64 v;
> +
> + switch (attr) {
> + case hwmon_power_input:
> + v = readq(feature->ioaddr + FME_PWR_STATUS);
> + *val = (long)(FIELD_GET(PWR_CONSUMED, v) * 1000000);
> + break;
> + case hwmon_power_max:
> + v = readq(feature->ioaddr + FME_PWR_THRESHOLD);
> + *val = (long)(FIELD_GET(PWR_THRESHOLD1, v) * 1000000);
> + break;
> + case hwmon_power_crit:
> + v = readq(feature->ioaddr + FME_PWR_THRESHOLD);
> + *val = (long)(FIELD_GET(PWR_THRESHOLD2, v) * 1000000);
> + break;
> + case hwmon_power_max_alarm:
> + v = readq(feature->ioaddr + FME_PWR_THRESHOLD);
> + *val = (long)FIELD_GET(PWR_THRESHOLD1_STATUS, v);
> + break;
> + case hwmon_power_crit_alarm:
> + v = readq(feature->ioaddr + FME_PWR_THRESHOLD);
> + *val = (long)FIELD_GET(PWR_THRESHOLD2_STATUS, v);
> + break;
> + default:
> + return -EOPNOTSUPP;
> + }
> +
> + return 0;
> +}
> +
> +static int power_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
> + u32 attr, int channel, long val)
> +{
> + struct dfl_feature_platform_data *pdata = dev_get_platdata(dev->parent);
> + struct dfl_feature *feature = dev_get_drvdata(dev);
> + int ret = 0;
> + u64 v;
> +
> + if (val < 0 || val > PWR_THRESHOLD_MAX_IN_UW)
> + return -EINVAL;
We usually use clamp_val() in such cases because there is no useful means
for the user to know the valid range.
> +
> + val = val / 1000000;
> +
> + mutex_lock(&pdata->lock);
> +
> + switch (attr) {
> + case hwmon_power_max:
> + v = readq(feature->ioaddr + FME_PWR_THRESHOLD);
> + v &= ~PWR_THRESHOLD1;
> + v |= FIELD_PREP(PWR_THRESHOLD1, val);
> + writeq(v, feature->ioaddr + FME_PWR_THRESHOLD);
> + break;
> + case hwmon_power_crit:
> + v = readq(feature->ioaddr + FME_PWR_THRESHOLD);
> + v &= ~PWR_THRESHOLD2;
> + v |= FIELD_PREP(PWR_THRESHOLD2, val);
> + writeq(v, feature->ioaddr + FME_PWR_THRESHOLD);
> + break;
> + default:
> + ret = -EOPNOTSUPP;
> + break;
> + }
> +
> + mutex_unlock(&pdata->lock);
> +
> + return ret;
> +}
> +
> +static umode_t power_hwmon_attrs_visible(const void *drvdata,
> + enum hwmon_sensor_types type,
> + u32 attr, int channel)
> +{
> + switch (attr) {
> + case hwmon_power_input:
> + case hwmon_power_max_alarm:
> + case hwmon_power_crit_alarm:
> + return 0444;
> + case hwmon_power_max:
> + case hwmon_power_crit:
> + return 0644;
> + }
> +
> + return 0;
> +}
> +
> +static const struct hwmon_ops power_hwmon_ops = {
> + .is_visible = power_hwmon_attrs_visible,
> + .read = power_hwmon_read,
> + .write = power_hwmon_write,
> +};
> +
> +static const struct hwmon_channel_info *power_hwmon_info[] = {
> + HWMON_CHANNEL_INFO(power, HWMON_P_INPUT |
> + HWMON_P_MAX | HWMON_P_MAX_ALARM |
> + HWMON_P_CRIT | HWMON_P_CRIT_ALARM),
> + NULL
> +};
> +
> +static const struct hwmon_chip_info power_hwmon_chip_info = {
> + .ops = &power_hwmon_ops,
> + .info = power_hwmon_info,
> +};
> +
> +static ssize_t power1_xeon_limit_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct dfl_feature *feature = dev_get_drvdata(dev);
> + u16 xeon_limit = 0;
> + u64 v;
> +
> + v = readq(feature->ioaddr + FME_PWR_XEON_LIMIT);
> +
> + if (FIELD_GET(XEON_PWR_EN, v))
> + xeon_limit = FIELD_GET(XEON_PWR_LIMIT, v);
> +
> + return sprintf(buf, "%u\n", xeon_limit * 100000);
> +}
> +
> +static ssize_t power1_fpga_limit_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct dfl_feature *feature = dev_get_drvdata(dev);
> + u16 fpga_limit = 0;
> + u64 v;
> +
> + v = readq(feature->ioaddr + FME_PWR_FPGA_LIMIT);
> +
> + if (FIELD_GET(FPGA_PWR_EN, v))
> + fpga_limit = FIELD_GET(FPGA_PWR_LIMIT, v);
> +
> + return sprintf(buf, "%u\n", fpga_limit * 100000);
> +}
> +
> +static ssize_t power1_ltr_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct dfl_feature *feature = dev_get_drvdata(dev);
> + u64 v;
> +
> + v = readq(feature->ioaddr + FME_PWR_STATUS);
> +
> + return sprintf(buf, "%u\n",
> + (unsigned int)FIELD_GET(FME_LATENCY_TOLERANCE, v));
> +}
> +
> +static DEVICE_ATTR_RO(power1_xeon_limit);
> +static DEVICE_ATTR_RO(power1_fpga_limit);
> +static DEVICE_ATTR_RO(power1_ltr);
> +
> +static struct attribute *power_extra_attrs[] = {
> + &dev_attr_power1_xeon_limit.attr,
> + &dev_attr_power1_fpga_limit.attr,
> + &dev_attr_power1_ltr.attr,
> + NULL
> +};
> +
> +ATTRIBUTE_GROUPS(power_extra);
> +
> +static int fme_power_mgmt_init(struct platform_device *pdev,
> + struct dfl_feature *feature)
> +{
> + struct device *hwmon;
> +
> + dev_dbg(&pdev->dev, "FME Power Management Init.\n");
> +
> + hwmon = devm_hwmon_device_register_with_info(&pdev->dev,
> + "dfl_fme_power", feature,
> + &power_hwmon_chip_info,
> + power_extra_groups);
> + if (IS_ERR(hwmon)) {
> + dev_err(&pdev->dev, "Fail to register power hwmon\n");
> + return PTR_ERR(hwmon);
> + }
> +
> + return 0;
> +}
> +
> +static void fme_power_mgmt_uinit(struct platform_device *pdev,
> + struct dfl_feature *feature)
> +{
> + dev_dbg(&pdev->dev, "FME Power Management UInit.\n");
> +}
> +
> +static const struct dfl_feature_id fme_power_mgmt_id_table[] = {
> + {.id = FME_FEATURE_ID_POWER_MGMT,},
> + {0,}
> +};
> +
> +static const struct dfl_feature_ops fme_power_mgmt_ops = {
> + .init = fme_power_mgmt_init,
> + .uinit = fme_power_mgmt_uinit,
> +};
> +
> static struct dfl_feature_driver fme_feature_drvs[] = {
> {
> .id_table = fme_hdr_id_table,
> @@ -418,6 +635,10 @@ static void fme_thermal_mgmt_uinit(struct platform_device *pdev,
> .ops = &fme_thermal_mgmt_ops,
> },
> {
> + .id_table = fme_power_mgmt_id_table,
> + .ops = &fme_power_mgmt_ops,
> + },
> + {
> .ops = NULL,
> },
> };
> --
> 1.8.3.1
>
