[PATCH v6 3/3] fpga: dfl: fme: add power management support

Wu Hao
2019-09-10T06:09:43Z

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@intel.com>
Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Moritz Fischer <mdf@kernel.org>
---
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
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
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.
v5: clamp threshold inputs in power_hwmon_write function.
update sysfs doc as threshold inputs are clamped now.
add more descriptions to ltr sysfs interface.
v6: rebase and clean up (remove empty uinit function).
update date in sysfs doc.
---
Documentation/ABI/testing/sysfs-platform-dfl-fme | 70 ++++++++
drivers/fpga/dfl-fme-main.c | 207 +++++++++++++++++++++++
2 files changed, 277 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-platform-dfl-fme b/Documentation/ABI/testing/sysfs-platform-dfl-fme
index c84b3c1..9ea4697 100644
--- a/Documentation/ABI/testing/sysfs-platform-dfl-fme
+++ b/Documentation/ABI/testing/sysfs-platform-dfl-fme
@@ -114,6 +114,7 @@ Contact: Wu Hao <hao.wu@intel.com>
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: September 2019
@@ -170,3 +171,72 @@ 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: September 2019
+KernelVersion: 5.4
+Contact: Wu Hao <hao.wu@intel.com>
+Description: Read-Only. It returns current FPGA power consumption in uW.
+
+What: /sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/power1_max
+Date: September 2019
+KernelVersion: 5.4
+Date: June 2019
+KernelVersion: 5.3
+Contact: Wu Hao <hao.wu@intel.com>
+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) and
+ clamped within the range from 0 to 127 Watts. Write fails with
+ -EINVAL if input parsing fails.
+
+What: /sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/power1_crit
+Date: September 2019
+KernelVersion: 5.4
+Contact: Wu Hao <hao.wu@intel.com>
+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) and
+ clamped within the range from 0 to 127 Watts. Write fails with
+ -EINVAL if input parsing fails.
+
+What: /sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/power1_max_alarm
+Date: September 2019
+KernelVersion: 5.4
+Contact: Wu Hao <hao.wu@intel.com>
+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: September 2019
+KernelVersion: 5.4
+Contact: Wu Hao <hao.wu@intel.com>
+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: September 2019
+KernelVersion: 5.4
+Contact: Wu Hao <hao.wu@intel.com>
+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: September 2019
+KernelVersion: 5.4
+Contact: Wu Hao <hao.wu@intel.com>
+Description: Read-Only. It returns power limit for FPGA in uW.
+
+What: /sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/power1_ltr
+Date: September 2019
+KernelVersion: 5.4
+Contact: Wu Hao <hao.wu@intel.com>
+Description: Read-only. Read this file to get current Latency Tolerance
+ Reporting (ltr) value. It returns 1 if all Accelerated
+ Function Units (AFUs) can tolerate latency >= 40us for memory
+ access or 0 if any AFU is latency sensitive (< 40us).
diff --git a/drivers/fpga/dfl-fme-main.c b/drivers/fpga/dfl-fme-main.c
index 752d71c..7c930e6 100644
--- a/drivers/fpga/dfl-fme-main.c
+++ b/drivers/fpga/dfl-fme-main.c
@@ -355,6 +355,209 @@ static int fme_thermal_mgmt_init(struct platform_device *pdev,
.init = fme_thermal_mgmt_init,
};

+#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)
+
+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;
+
+ val = clamp_val(val / 1000000, 0, PWR_THRESHOLD_MAX);
+
+ 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;
+
+ 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 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,
+};
+
static struct dfl_feature_driver fme_feature_drvs[] = {
{
.id_table = fme_hdr_id_table,
@@ -373,6 +576,10 @@ static int fme_thermal_mgmt_init(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