Re: [PATCH v3 2/3] fpga: dfl: fme: add thermal management support

[Wu Hao]

On Wed, Jun 05, 2019 at 02:10:31PM -0700, Guenter Roeck wrote:
> On Mon, May 27, 2019 at 02:06:55PM +0800, Wu Hao wrote:
> > This patch adds support to thermal management private feature for DFL
> > FPGA Management Engine (FME). This private feature driver registers
> > a hwmon for thermal/temperature monitoring (hwmon temp1_input).
> > If hardware automatic throttling is supported by this hardware, then
> > driver also exposes sysfs interfaces under hwmon for thresholds
> > (temp1_max/ crit/ emergency), threshold alarms (temp1_max_alarm/
> > temp1_crit_alarm) and throttling policy (temp1_max_policy).
> > 
> > Signed-off-by: Luwei Kang <luwei.kang@xxxxxxxxx>
> > Signed-off-by: Russ Weight <russell.h.weight@xxxxxxxxx>
> > Signed-off-by: Xu Yilun <yilun.xu@xxxxxxxxx>
> > Signed-off-by: Wu Hao <hao.wu@xxxxxxxxx>
> > ----
> > v2: create a dfl_fme_thermal hwmon to expose thermal information.
> >     move all sysfs interfaces under hwmon
> > 	tempareture       --> hwmon temp1_input
> > 	threshold1        --> hwmon temp1_alarm
> > 	threshold2        --> hwmon temp1_crit
> > 	trip_threshold    --> hwmon temp1_emergency
> > 	threshold1_status --> hwmon temp1_alarm_status
> > 	threshold2_status --> hwmon temp1_crit_status
> > 	threshold1_policy --> hwmon temp1_alarm_policy
> > v3: rename some hwmon sysfs interfaces to follow hwmon ABI.
> > 	temp1_alarm        --> temp1_max
> > 	temp1_alarm_status --> temp1_max_alarm
> > 	temp1_crit_status  --> temp1_crit_alarm
> > 	temp1_alarm_policy --> temp1_max_policy
> >     update sysfs doc for above sysfs interface changes.
> >     replace scnprintf with sprintf in sysfs interface.
> > ---
> >  Documentation/ABI/testing/sysfs-platform-dfl-fme |  64 ++++++++
> >  drivers/fpga/Kconfig                             |   2 +-
> >  drivers/fpga/dfl-fme-main.c                      | 196 +++++++++++++++++++++++
> >  3 files changed, 261 insertions(+), 1 deletion(-)
> > 
> > diff --git a/Documentation/ABI/testing/sysfs-platform-dfl-fme b/Documentation/ABI/testing/sysfs-platform-dfl-fme
> > index 63a02cb..0a0b7b9 100644
> > --- a/Documentation/ABI/testing/sysfs-platform-dfl-fme
> > +++ b/Documentation/ABI/testing/sysfs-platform-dfl-fme
> > @@ -212,3 +212,67 @@ Description:	Read-Write. Read this file for current status of port level
> >  		fabric counters. Write "1" to enable port level fabric counters.
> >  		Once port level fabric counters are enabled, device level fabric
> >  		counters will be disabled automatically.
> > +
> > +What:		/sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/name
> > +Date:		May 2019
> > +KernelVersion:	5.3
> > +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
> > +
> > +What:		/sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/temp1_input
> > +Date:		May 2019
> > +KernelVersion:	5.3
> > +Contact:	Wu Hao <hao.wu@xxxxxxxxx>
> > +Description:	Read-Only. It returns FPGA device temperature in millidegrees
> > +		Celsius.
> > +
> > +What:		/sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/temp1_max
> > +Date:		May 2019
> > +KernelVersion:	5.3
> > +Contact:	Wu Hao <hao.wu@xxxxxxxxx>
> > +Description:	Read-Only. It returns hardware threshold1 temperature in
> > +		millidegrees Celsius. If temperature rises at or above this
> > +		threshold, hardware starts 50% or 90% throttling (see
> > +		'temp1_max_policy').
> > +
> > +What:		/sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/temp1_crit
> > +Date:		May 2019
> > +KernelVersion:	5.3
> > +Contact:	Wu Hao <hao.wu@xxxxxxxxx>
> > +Description:	Read-Only. It returns hardware threshold2 temperature in
> > +		millidegrees Celsius. If temperature rises at or above this
> > +		threshold, hardware starts 100% throttling.
> > +
> > +What:		/sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/temp1_emergency
> > +Date:		May 2019
> > +KernelVersion:	5.3
> > +Contact:	Wu Hao <hao.wu@xxxxxxxxx>
> > +Description:	Read-Only. It returns hardware trip threshold temperature in
> > +		millidegrees Celsius. If temperature rises at or above this
> > +		threshold, a fatal event will be triggered to board management
> > +		controller (BMC) to shutdown FPGA.
> > +
> > +What:		/sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/temp1_max_alarm
> > +Date:		May 2019
> > +KernelVersion:	5.3
> > +Contact:	Wu Hao <hao.wu@xxxxxxxxx>
> > +Description:	Read-only. It returns 1 if temperature is currently at or above
> > +		hardware threshold1 (see 'temp1_max'), otherwise 0.
> > +
> > +What:		/sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/temp1_crit_alarm
> > +Date:		May 2019
> > +KernelVersion:	5.3
> > +Contact:	Wu Hao <hao.wu@xxxxxxxxx>
> > +Description:	Read-only. It returns 1 if temperature is currently at or above
> > +		hardware threshold2 (see 'temp1_crit'), otherwise 0.
> > +
> > +What:		/sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/temp1_max_policy
> > +Date:		May 2019
> > +KernelVersion:	5.3
> > +Contact:	Wu Hao <hao.wu@xxxxxxxxx>
> > +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)
> > diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> > index d892f3e..36551d6 100644
> > --- a/drivers/fpga/Kconfig
> > +++ b/drivers/fpga/Kconfig
> > @@ -154,7 +154,7 @@ config FPGA_DFL
> >  
> >  config FPGA_DFL_FME
> >  	tristate "FPGA DFL FME Driver"
> > -	depends on FPGA_DFL
> > +	depends on FPGA_DFL && HWMON
> >  	help
> >  	  The FPGA Management Engine (FME) is a feature device implemented
> >  	  under Device Feature List (DFL) framework. Select this option to
> > diff --git a/drivers/fpga/dfl-fme-main.c b/drivers/fpga/dfl-fme-main.c
> > index 4a5b25d..91152d5 100644
> > --- a/drivers/fpga/dfl-fme-main.c
> > +++ b/drivers/fpga/dfl-fme-main.c
> > @@ -14,6 +14,8 @@
> >   *   Henry Mitchel <henry.mitchel@xxxxxxxxx>
> >   */
> >  
> > +#include <linux/hwmon.h>
> > +#include <linux/hwmon-sysfs.h>
> >  #include <linux/kernel.h>
> >  #include <linux/module.h>
> >  #include <linux/uaccess.h>
> > @@ -217,6 +219,196 @@ static long fme_hdr_ioctl(struct platform_device *pdev,
> >  	.ioctl = fme_hdr_ioctl,
> >  };
> >  
> > +#define FME_THERM_THRESHOLD	0x8
> > +#define TEMP_THRESHOLD1		GENMASK_ULL(6, 0)
> > +#define TEMP_THRESHOLD1_EN	BIT_ULL(7)
> > +#define TEMP_THRESHOLD2		GENMASK_ULL(14, 8)
> > +#define TEMP_THRESHOLD2_EN	BIT_ULL(15)
> > +#define TRIP_THRESHOLD		GENMASK_ULL(30, 24)
> > +#define TEMP_THRESHOLD1_STATUS	BIT_ULL(32)		/* threshold1 reached */
> > +#define TEMP_THRESHOLD2_STATUS	BIT_ULL(33)		/* threshold2 reached */
> > +/* threshold1 policy: 0 - AP2 (90% throttle) / 1 - AP1 (50% throttle) */
> > +#define TEMP_THRESHOLD1_POLICY	BIT_ULL(44)
> > +
> > +#define FME_THERM_RDSENSOR_FMT1	0x10
> > +#define FPGA_TEMPERATURE	GENMASK_ULL(6, 0)
> > +
> > +#define FME_THERM_CAP		0x20
> > +#define THERM_NO_THROTTLE	BIT_ULL(0)
> > +
> > +#define MD_PRE_DEG
> > +
> > +static bool fme_thermal_throttle_support(void __iomem *base)
> > +{
> > +	u64 v = readq(base + FME_THERM_CAP);
> > +
> > +	return FIELD_GET(THERM_NO_THROTTLE, v) ? false : true;
> > +}
> > +
> > +static umode_t thermal_hwmon_attrs_visible(const void *drvdata,
> > +					   enum hwmon_sensor_types type,
> > +					   u32 attr, int channel)
> > +{
> > +	const struct dfl_feature *feature = drvdata;
> > +
> > +	/* temperature is always supported, and check hardware cap for others */
> > +	if (attr == hwmon_temp_input)
> > +		return 0444;
> > +
> > +	return fme_thermal_throttle_support(feature->ioaddr) ? 0444 : 0;
> > +}
> > +
> > +static int thermal_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_temp_input:
> > +		v = readq(feature->ioaddr + FME_THERM_RDSENSOR_FMT1);
> > +		*val = (long)(FIELD_GET(FPGA_TEMPERATURE, v) * 1000);
> > +		break;
> > +	case hwmon_temp_max:
> > +		v = readq(feature->ioaddr + FME_THERM_THRESHOLD);
> > +		*val = (long)(FIELD_GET(TEMP_THRESHOLD1, v) * 1000);
> > +		break;
> > +	case hwmon_temp_crit:
> > +		v = readq(feature->ioaddr + FME_THERM_THRESHOLD);
> > +		*val = (long)(FIELD_GET(TEMP_THRESHOLD2, v) * 1000);
> > +		break;
> > +	case hwmon_temp_emergency:
> > +		v = readq(feature->ioaddr + FME_THERM_THRESHOLD);
> > +		*val = (long)(FIELD_GET(TRIP_THRESHOLD, v) * 1000);
> > +		break;
> > +	case hwmon_temp_max_alarm:
> > +		v = readq(feature->ioaddr + FME_THERM_THRESHOLD);
> > +		*val = (long)FIELD_GET(TEMP_THRESHOLD1_STATUS, v);
> > +		break;
> > +	case hwmon_temp_crit_alarm:
> > +		v = readq(feature->ioaddr + FME_THERM_THRESHOLD);
> > +		*val = (long)FIELD_GET(TEMP_THRESHOLD2_STATUS, v);
> > +		break;
> > +	default:
> > +		return -EOPNOTSUPP;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct hwmon_ops thermal_hwmon_ops = {
> > +	.is_visible = thermal_hwmon_attrs_visible,
> > +	.read = thermal_hwmon_read,
> > +};
> > +
> > +static const u32 thermal_hwmon_temp_config[] = {
> > +	HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT | HWMON_T_EMERGENCY |
> > +	HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM,
> > +	0
> > +};
> > +
> > +static const struct hwmon_channel_info hwmon_temp_info = {
> > +	.type = hwmon_temp,
> > +	.config = thermal_hwmon_temp_config,
> > +};
> > +
> > +static const struct hwmon_channel_info *thermal_hwmon_info[] = {
> > +	&hwmon_temp_info,
> > +	NULL
> > +};
> 
> Please use the HWMON_CHANNEL_INFO() macro to reduce boilerplate code.

Sure, will fix this in the next version. Thanks a lot!

Hao

> 
> Thanks,
> Guenter
>