Messages in this thread | | | Subject | Re: [PATCH 11/14] hwmon: peci: Add cputemp driver | From | Guenter Roeck <> | Date | Fri, 30 Jul 2021 15:04:05 -0700 |
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On 7/30/21 2:51 PM, Winiarska, Iwona wrote: > On Tue, 2021-07-27 at 07:06 +0000, Zev Weiss wrote: >> On Mon, Jul 12, 2021 at 05:04:44PM CDT, Iwona Winiarska wrote: >>> Add peci-cputemp driver for Digital Thermal Sensor (DTS) thermal >>> readings of the processor package and processor cores that are >>> accessible via the PECI interface. >>> >>> The main use case for the driver (and PECI interface) is out-of-band >>> management, where we're able to obtain the DTS readings from an external >>> entity connected with PECI, e.g. BMC on server platforms. >>> >>> Co-developed-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> >>> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> >>> Signed-off-by: Iwona Winiarska <iwona.winiarska@intel.com> >>> Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> >>> --- >>> MAINTAINERS | 7 + >>> drivers/hwmon/Kconfig | 2 + >>> drivers/hwmon/Makefile | 1 + >>> drivers/hwmon/peci/Kconfig | 18 ++ >>> drivers/hwmon/peci/Makefile | 5 + >>> drivers/hwmon/peci/common.h | 46 ++++ >>> drivers/hwmon/peci/cputemp.c | 503 +++++++++++++++++++++++++++++++++++ >>> 7 files changed, 582 insertions(+) >>> create mode 100644 drivers/hwmon/peci/Kconfig >>> create mode 100644 drivers/hwmon/peci/Makefile >>> create mode 100644 drivers/hwmon/peci/common.h >>> create mode 100644 drivers/hwmon/peci/cputemp.c >>> >>> diff --git a/MAINTAINERS b/MAINTAINERS >>> index f47b5f634293..35ba9e3646bd 100644 >>> --- a/MAINTAINERS >>> +++ b/MAINTAINERS >>> @@ -14504,6 +14504,13 @@ L: platform-driver-x86@vger.kernel.org >>> S: Maintained >>> F: drivers/platform/x86/peaq-wmi.c >>> >>> +PECI HARDWARE MONITORING DRIVERS >>> +M: Iwona Winiarska <iwona.winiarska@intel.com> >>> +R: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> >>> +L: linux-hwmon@vger.kernel.org >>> +S: Supported >>> +F: drivers/hwmon/peci/ >>> + >>> PECI SUBSYSTEM >>> M: Iwona Winiarska <iwona.winiarska@intel.com> >>> R: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> >>> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig >>> index e3675377bc5d..61c0e3404415 100644 >>> --- a/drivers/hwmon/Kconfig >>> +++ b/drivers/hwmon/Kconfig >>> @@ -1507,6 +1507,8 @@ config SENSORS_PCF8591 >>> These devices are hard to detect and rarely found on mainstream >>> hardware. If unsure, say N. >>> >>> +source "drivers/hwmon/peci/Kconfig" >>> + >>> source "drivers/hwmon/pmbus/Kconfig" >>> >>> config SENSORS_PWM_FAN >>> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile >>> index d712c61c1f5e..f52331f212ed 100644 >>> --- a/drivers/hwmon/Makefile >>> +++ b/drivers/hwmon/Makefile >>> @@ -202,6 +202,7 @@ obj-$(CONFIG_SENSORS_WM8350) += wm8350-hwmon.o >>> obj-$(CONFIG_SENSORS_XGENE) += xgene-hwmon.o >>> >>> obj-$(CONFIG_SENSORS_OCC) += occ/ >>> +obj-$(CONFIG_SENSORS_PECI) += peci/ >>> obj-$(CONFIG_PMBUS) += pmbus/ >>> >>> ccflags-$(CONFIG_HWMON_DEBUG_CHIP) := -DDEBUG >>> diff --git a/drivers/hwmon/peci/Kconfig b/drivers/hwmon/peci/Kconfig >>> new file mode 100644 >>> index 000000000000..e10eed68d70a >>> --- /dev/null >>> +++ b/drivers/hwmon/peci/Kconfig >>> @@ -0,0 +1,18 @@ >>> +# SPDX-License-Identifier: GPL-2.0-only >>> + >>> +config SENSORS_PECI_CPUTEMP >>> + tristate "PECI CPU temperature monitoring client" >>> + depends on PECI >>> + select SENSORS_PECI >>> + select PECI_CPU >>> + help >>> + If you say yes here you get support for the generic Intel PECI >>> + cputemp driver which provides Digital Thermal Sensor (DTS) thermal >>> + readings of the CPU package and CPU cores that are accessible via >>> + the processor PECI interface. >>> + >>> + This driver can also be built as a module. If so, the module >>> + will be called peci-cputemp. >>> + >>> +config SENSORS_PECI >>> + tristate >>> diff --git a/drivers/hwmon/peci/Makefile b/drivers/hwmon/peci/Makefile >>> new file mode 100644 >>> index 000000000000..e8a0ada5ab1f >>> --- /dev/null >>> +++ b/drivers/hwmon/peci/Makefile >>> @@ -0,0 +1,5 @@ >>> +# SPDX-License-Identifier: GPL-2.0-only >>> + >>> +peci-cputemp-y := cputemp.o >>> + >>> +obj-$(CONFIG_SENSORS_PECI_CPUTEMP) += peci-cputemp.o >>> diff --git a/drivers/hwmon/peci/common.h b/drivers/hwmon/peci/common.h >>> new file mode 100644 >>> index 000000000000..54580c100d06 >>> --- /dev/null >>> +++ b/drivers/hwmon/peci/common.h >>> @@ -0,0 +1,46 @@ >>> +/* SPDX-License-Identifier: GPL-2.0-only */ >>> +/* Copyright (c) 2021 Intel Corporation */ >>> + >>> +#include <linux/types.h> >>> + >>> +#ifndef __PECI_HWMON_COMMON_H >>> +#define __PECI_HWMON_COMMON_H >>> + >>> +#define UPDATE_INTERVAL_DEFAULT HZ >>> + >>> +/** >>> + * struct peci_sensor_data - PECI sensor information >>> + * @valid: flag to indicate the sensor value is valid >>> + * @value: sensor value in milli units >>> + * @last_updated: time of the last update in jiffies >>> + */ >>> +struct peci_sensor_data { >>> + unsigned int valid; >> >> From what I can see it looks like the 'valid' member here is strictly a >> one-shot has-this-value-ever-been-set indicator, which seems a bit >> wasteful to keep around forever post initialization; couldn't the same >> information be inferred from checking last_updated != 0 or something? > > That's just expressed in jiffies, which means it can overflow (we're just > unlikely to hit it - but IIUC it can happen). > Doing it this way would require making sure that last_updated is never set to 0 > in code that does the update. I don't think it's worth to add more complexity > there just to save a couple of bytes. >
Correct. There are ways around that (eg by setting 'last_updated' to some time in the past), but that isn't really worth the trouble.
'valid' should be bool, though, not "unsigned int".
Guenter
>> >>> + s32 value; >>> + unsigned long last_updated; >>> +}; >>> + >>> +/** >>> + * peci_sensor_need_update() - check whether sensor update is needed or not >>> + * @sensor: pointer to sensor data struct >>> + * >>> + * Return: true if update is needed, false if not. >>> + */ >>> + >>> +static inline bool peci_sensor_need_update(struct peci_sensor_data *sensor) >>> +{ >>> + return !sensor->valid || >>> + time_after(jiffies, sensor->last_updated + >>> UPDATE_INTERVAL_DEFAULT); >>> +} >>> + >>> +/** >>> + * peci_sensor_mark_updated() - mark the sensor is updated >>> + * @sensor: pointer to sensor data struct >>> + */ >>> +static inline void peci_sensor_mark_updated(struct peci_sensor_data >>> *sensor) >>> +{ >>> + sensor->valid = 1; >>> + sensor->last_updated = jiffies; >>> +} >>> + >>> +#endif /* __PECI_HWMON_COMMON_H */ >>> diff --git a/drivers/hwmon/peci/cputemp.c b/drivers/hwmon/peci/cputemp.c >>> new file mode 100644 >>> index 000000000000..56a526471687 >>> --- /dev/null >>> +++ b/drivers/hwmon/peci/cputemp.c >>> @@ -0,0 +1,503 @@ >>> +// SPDX-License-Identifier: GPL-2.0-only >>> +// Copyright (c) 2018-2021 Intel Corporation >>> + >>> +#include <linux/auxiliary_bus.h> >>> +#include <linux/bitfield.h> >>> +#include <linux/bitops.h> >>> +#include <linux/hwmon.h> >>> +#include <linux/jiffies.h> >>> +#include <linux/module.h> >>> +#include <linux/peci.h> >>> +#include <linux/peci-cpu.h> >>> +#include <linux/units.h> >>> +#include <linux/x86/intel-family.h> >>> + >>> +#include "common.h" >>> + >>> +#define CORE_NUMS_MAX 64 >>> + >>> +#define DEFAULT_CHANNEL_NUMS 5 >> >> DEFAULT_ seems like a slightly odd prefix for this (it's not something >> that can really be overridden or anything); would BASE_ perhaps be a bit >> more appropriate? > > Ack. > >> >>> +#define CORETEMP_CHANNEL_NUMS CORE_NUMS_MAX >>> +#define CPUTEMP_CHANNEL_NUMS (DEFAULT_CHANNEL_NUMS + >>> CORETEMP_CHANNEL_NUMS) >>> + >>> +#define TEMP_TARGET_FAN_TEMP_MASK GENMASK(15, 8) >>> +#define TEMP_TARGET_REF_TEMP_MASK GENMASK(23, 16) >>> +#define TEMP_TARGET_TJ_OFFSET_MASK GENMASK(29, 24) >>> + >>> +#define DTS_MARGIN_MASK GENMASK(15, 0) >>> +#define PCS_MODULE_TEMP_MASK GENMASK(15, 0) >>> + >>> +#define DTS_FIXED_POINT_FRACTION 64 >>> + >>> +struct resolved_cores_reg { >>> + u8 bus; >>> + u8 dev; >>> + u8 func; >>> + u8 offset; >>> +}; >>> + >>> +struct cpu_info { >>> + struct resolved_cores_reg *reg; >>> + u8 min_peci_revision; >> >> As with the dimmtemp driver, min_peci_revision appears unused here, >> though in this case if it were removed there'd only be one (pointer) >> member left in struct cpu_info, so we could perhaps remove it as well >> and then also a level of indirection in peci_cputemp_ids/cpu_{hsx,icx} >> too? > > As I mentioned in reply to previous patch comment, it'll be used to validate if > PECI device revision matches driver requirements. > >> >>> +}; >>> + >>> +struct peci_cputemp { >>> + struct peci_device *peci_dev; >>> + struct device *dev; >>> + const char *name; >>> + const struct cpu_info *gen_info; >>> + struct { >>> + struct peci_sensor_data die; >>> + struct peci_sensor_data dts; >>> + struct peci_sensor_data tcontrol; >>> + struct peci_sensor_data tthrottle; >>> + struct peci_sensor_data tjmax; >>> + struct peci_sensor_data core[CORETEMP_CHANNEL_NUMS]; >>> + } temp; >>> + const char **coretemp_label; >>> + DECLARE_BITMAP(core_mask, CORE_NUMS_MAX); >>> +}; >>> + >>> +enum cputemp_channels { >>> + channel_die, >>> + channel_dts, >>> + channel_tcontrol, >>> + channel_tthrottle, >>> + channel_tjmax, >>> + channel_core, >>> +}; >>> + >>> +static const char *cputemp_label[DEFAULT_CHANNEL_NUMS] = { >> >> static const char * const cputemp_label? (That is, const pointer to >> const char, rather than non-const pointer to const char.) > > Ack. > >> >>> + "Die", >>> + "DTS", >>> + "Tcontrol", >>> + "Tthrottle", >>> + "Tjmax", >>> +}; >>> + >>> +static int get_temp_targets(struct peci_cputemp *priv) >>> +{ >>> + s32 tthrottle_offset, tcontrol_margin; >>> + u32 pcs; >>> + int ret; >>> + >>> + /* >>> + * Just use only the tcontrol marker to determine if target values >>> need >>> + * update. >>> + */ >>> + if (!peci_sensor_need_update(&priv->temp.tcontrol)) >>> + return 0; >>> + >>> + ret = peci_pcs_read(priv->peci_dev, PECI_PCS_TEMP_TARGET, 0, &pcs); >>> + if (ret) >>> + return ret; >>> + >>> + priv->temp.tjmax.value = FIELD_GET(TEMP_TARGET_REF_TEMP_MASK, pcs) * >>> MILLIDEGREE_PER_DEGREE; >>> + >>> + tcontrol_margin = FIELD_GET(TEMP_TARGET_FAN_TEMP_MASK, pcs); >>> + tcontrol_margin = sign_extend32(tcontrol_margin, 7) * >>> MILLIDEGREE_PER_DEGREE; >>> + priv->temp.tcontrol.value = priv->temp.tjmax.value - >>> tcontrol_margin; >>> + >>> + tthrottle_offset = FIELD_GET(TEMP_TARGET_TJ_OFFSET_MASK, pcs) * >>> MILLIDEGREE_PER_DEGREE; >>> + priv->temp.tthrottle.value = priv->temp.tjmax.value - >>> tthrottle_offset; >>> + >>> + peci_sensor_mark_updated(&priv->temp.tcontrol); >>> + >>> + return 0; >>> +} >>> + >>> +/* >>> + * Processors return a value of DTS reading in S10.6 fixed point format >>> + * (sign, 10 bits signed integer value, 6 bits fractional). >> >> This parenthetical reads to me like it's describing 17 bits -- I'm not a >> PECI expert, but from my reading of the (somewhat skimpy) docs I've got >> on it I'd suggest a description more like "sign, 9-bit magnitude, 6-bit >> fraction". > > You're right, adding "sign" here was not intentional. > I'll change it to: > "16 bits: sign, 9-bit magnitude, 6-bit fraction" > or > "16 bits: 10-bit signed magnitude, 6-bit fraction" > > Thanks > -Iwona >
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