Re: [PATCH 11/14] hwmon: peci: Add cputemp driver

Winiarska, Iwona
2021-07-19T23:34:30Z

On Thu, 2021-07-15 at 10:45 -0700, Guenter Roeck wrote:
> On Tue, Jul 13, 2021 at 12:04:44AM +0200, 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>
>
> Note: Due to lack of revision information, this review does not take
> any previous discussions into account, and it may miss critical information.
> For a final review I'll have to compare the code against earlier versions
> to determine if there are any relevant changes and if all comments
> have been addressed. This may take some time.
>

Thank you for taking a look at the patches.

Unfortunately, the changes needed in the PECI-core part impacted HWMON as well.
I tried to minimize refactoring, but changes are rather big (in my opinion -
which is why I assumed that full changelog won't be helpful).
After taking over the series I noted your comments to v11. The changes you
requested are either already there or the code no longer exists due to
refactoring (but after going through that again, I noticed the duplicated
CORE_NUMS_MAX define - I'll remove it in v2).

> > ---
> >  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;
>
> Please use bool.
>

Ok.

> > +       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);
>
>
> Since there is no other update interval, _DEFAULT does not have any value.
> Please drop. Also, please select a prefix such as PECI_.
>

Sure - I'll go with PECI_HWMON_UPDATE_INTERVAL.

> > +}
> > +
> > +/**
> > + * 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;
>
>                 = true;
>

Ok.

> > +       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
> > +#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;
> > +};
> > +
> > +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] = {
> > +       "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;
> > +
> True for the entire code: Please explain how this avoids race conditions
> without locking between the condition check here and the call to
> peci_sensor_mark_updated() below. The explanation needs to be added
> as comment into the code for later reference.
>

You're right, there is a race here that may cause PECI command to be triggered
more than once. It doesn't have any impact on correctness though.
I could add a comment explaining that, but I guess just adding a mutex to avoid
the race makes more sense.

> > +       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).
> > + * Error codes:
> > + *   0x8000: General sensor error
> > + *   0x8001: Reserved
> > + *   0x8002: Underflow on reading value
> > + *   0x8003-0x81ff: Reserved
> > + */
> > +static bool dts_valid(s32 val)
> > +{
> > +       return val < 0x8000 || val > 0x81ff;
> > +}
> > +
> > +static s32 dts_to_millidegree(s32 val)
> > +{
> > +       return sign_extend32(val, 15) * MILLIDEGREE_PER_DEGREE /
> > DTS_FIXED_POINT_FRACTION;
> > +}
> > +
> > +static int get_die_temp(struct peci_cputemp *priv)
> > +{
> > +       s16 temp;
> > +       int ret;
> > +
> > +       if (!peci_sensor_need_update(&priv->temp.die))
> > +               return 0;
> > +
> > +       ret = peci_temp_read(priv->peci_dev, &temp);
> > +       if (ret)
> > +               return ret;
> > +
> > +       if (!dts_valid(temp))
> > +               return -EIO;
> > +
> > +       /* Note that the tjmax should be available before calling it */
> > +       priv->temp.die.value = priv->temp.tjmax.value +
> > dts_to_millidegree(temp);
> > +
> > +       peci_sensor_mark_updated(&priv->temp.die);
> > +
> > +       return 0;
> > +}
> > +
> > +static int get_dts(struct peci_cputemp *priv)
> > +{
> > +       s32 dts_margin;
> > +       u32 pcs;
> > +       int ret;
> > +
> > +       if (!peci_sensor_need_update(&priv->temp.dts))
> > +               return 0;
> > +
> > +       ret = peci_pcs_read(priv->peci_dev, PECI_PCS_THERMAL_MARGIN, 0, &pcs);
> > +       if (ret)
> > +               return ret;
> > +
> > +       dts_margin = FIELD_GET(DTS_MARGIN_MASK, pcs);
> > +       if (!dts_valid(dts_margin))
> > +               return -EIO;
> > +
> > +       /* Note that the tcontrol should be available before calling it */
> > +       priv->temp.dts.value = priv->temp.tcontrol.value -
> > dts_to_millidegree(dts_margin);
> > +
> > +       peci_sensor_mark_updated(&priv->temp.dts);
> > +
> > +       return 0;
> > +}
> > +
> > +static int get_core_temp(struct peci_cputemp *priv, int core_index)
> > +{
> > +       s32 core_dts_margin;
> > +       u32 pcs;
> > +       int ret;
> > +
> > +       if (!peci_sensor_need_update(&priv->temp.core[core_index]))
> > +               return 0;
> > +
> > +       ret = peci_pcs_read(priv->peci_dev, PECI_PCS_MODULE_TEMP, core_index,
> > &pcs);
> > +       if (ret)
> > +               return ret;
> > +
> > +       core_dts_margin = FIELD_GET(PCS_MODULE_TEMP_MASK, pcs);
> > +       if (!dts_valid(core_dts_margin))
> > +               return -EIO;
> > +
> > +       /* Note that the tjmax should be available before calling it */
> > +       priv->temp.core[core_index].value =
> > +               priv->temp.tjmax.value + dts_to_millidegree(core_dts_margin);
> > +
> > +       peci_sensor_mark_updated(&priv->temp.core[core_index]);
> > +
> > +       return 0;
> > +}
> > +
> > +static int cputemp_read_string(struct device *dev, enum hwmon_sensor_types
> > type,
> > +                              u32 attr, int channel, const char **str)
> > +{
> > +       struct peci_cputemp *priv = dev_get_drvdata(dev);
> > +
> > +       if (attr != hwmon_temp_label)
> > +               return -EOPNOTSUPP;
> > +
> > +       *str = channel < channel_core ?
> > +               cputemp_label[channel] : priv->coretemp_label[channel -
> > channel_core];
> > +
> > +       return 0;
> > +}
> > +
> > +static int cputemp_read(struct device *dev, enum hwmon_sensor_types type,
> > +                       u32 attr, int channel, long *val)
> > +{
> > +       struct peci_cputemp *priv = dev_get_drvdata(dev);
> > +       int ret, core_index;
> > +
> > +       ret = get_temp_targets(priv);
> > +       if (ret)
> > +               return ret;
> > +
> > +       switch (attr) {
> > +       case hwmon_temp_input:
> > +               switch (channel) {
> > +               case channel_die:
> > +                       ret = get_die_temp(priv);
> > +                       if (ret)
> > +                               return ret;
> > +
> > +                       *val = priv->temp.die.value;
> > +                       break;
> > +               case channel_dts:
> > +                       ret = get_dts(priv);
> > +                       if (ret)
> > +                               return ret;
> > +
> > +                       *val = priv->temp.dts.value;
> > +                       break;
> > +               case channel_tcontrol:
> > +                       *val = priv->temp.tcontrol.value;
> > +                       break;
> > +               case channel_tthrottle:
> > +                       *val = priv->temp.tthrottle.value;
> > +                       break;
> > +               case channel_tjmax:
> > +                       *val = priv->temp.tjmax.value;
> > +                       break;
> > +               default:
> > +                       core_index = channel - channel_core;
> > +                       ret = get_core_temp(priv, core_index);
> > +                       if (ret)
> > +                               return ret;
> > +
> > +                       *val = priv->temp.core[core_index].value;
> > +                       break;
> > +               }
> > +               break;
> > +       case hwmon_temp_max:
> > +               *val = priv->temp.tcontrol.value;
> > +               break;
> > +       case hwmon_temp_crit:
> > +               *val = priv->temp.tjmax.value;
> > +               break;
> > +       case hwmon_temp_crit_hyst:
> > +               *val = priv->temp.tjmax.value - priv->temp.tcontrol.value;
> > +               break;
> > +       default:
> > +               return -EOPNOTSUPP;
> > +       }
> > +
> > +       return 0;
> > +}
> > +
> > +static umode_t cputemp_is_visible(const void *data, enum hwmon_sensor_types
> > type,
> > +                                 u32 attr, int channel)
> > +{
> > +       const struct peci_cputemp *priv = data;
> > +
> > +       if (channel > CPUTEMP_CHANNEL_NUMS)
> > +               return 0;
> > +
> > +       if (channel < channel_core)
> > +               return 0444;
> > +
> > +       if (test_bit(channel - channel_core, priv->core_mask))
> > +               return 0444;
> > +
> > +       return 0;
> > +}
> > +
> > +static int init_core_mask(struct peci_cputemp *priv)
> > +{
> > +       struct peci_device *peci_dev = priv->peci_dev;
> > +       struct resolved_cores_reg *reg = priv->gen_info->reg;
> > +       u64 core_mask;
> > +       u32 data;
> > +       int ret;
> > +
> > +       /* Get the RESOLVED_CORES register value */
> > +       switch (peci_dev->info.model) {
> > +       case INTEL_FAM6_ICELAKE_X:
> > +       case INTEL_FAM6_ICELAKE_D:
> > +               ret = peci_ep_pci_local_read(peci_dev, 0, reg->bus, reg->dev,
> > +                                            reg->func, reg->offset + 4,
> > &data);
> > +               if (ret)
> > +                       return ret;
> > +
> > +               core_mask = (u64)data << 32;
> > +
> > +               ret = peci_ep_pci_local_read(peci_dev, 0, reg->bus, reg->dev,
> > +                                            reg->func, reg->offset, &data);
> > +               if (ret)
> > +                       return ret;
> > +
> > +               core_mask |= data;
> > +
> > +               break;
> > +       default:
> > +               ret = peci_pci_local_read(peci_dev, reg->bus, reg->dev,
> > +                                         reg->func, reg->offset, &data);
> > +               if (ret)
> > +                       return ret;
> > +
> > +               core_mask = data;
> > +
> > +               break;
> > +       }
> > +
> > +       if (!core_mask)
> > +               return -EIO;
> > +
> > +       bitmap_from_u64(priv->core_mask, core_mask);
> > +
> > +       return 0;
> > +}
> > +
> > +static int create_temp_label(struct peci_cputemp *priv)
> > +{
> > +       unsigned long core_max = find_last_bit(priv->core_mask,
> > CORE_NUMS_MAX);
> > +       int i;
> > +
> > +       priv->coretemp_label = devm_kzalloc(priv->dev, core_max * sizeof(char
> > *), GFP_KERNEL);
> > +       if (!priv->coretemp_label)
> > +               return -ENOMEM;
> > +
> > +       for_each_set_bit(i, priv->core_mask, CORE_NUMS_MAX) {
> > +               priv->coretemp_label[i] = devm_kasprintf(priv->dev,
> > GFP_KERNEL, "Core %d", i);
> > +               if (!priv->coretemp_label[i])
> > +                       return -ENOMEM;
> > +       }
> > +
> > +       return 0;
> > +}
> > +
> > +static void check_resolved_cores(struct peci_cputemp *priv)
> > +{
> > +       int ret;
> > +
> > +       ret = init_core_mask(priv);
> > +       if (ret)
> > +               return;
> > +
> > +       ret = create_temp_label(priv);
> > +       if (ret)
> > +               bitmap_zero(priv->core_mask, CORE_NUMS_MAX);
>
> This needs a comment explaining why it is ok to ignore the above errors.
>
> I understand it is because the non-core data will still be available.
> Yet, it still needs to be explained so others don't need to examine
> the code to figure out the reason.
>

Right - I'll add a:
/*
* Failure to resolve cores is non-critical, we're still able to
* provide other sensor data.
*/

> > +}
> > +
> > +static const struct hwmon_ops peci_cputemp_ops = {
> > +       .is_visible = cputemp_is_visible,
> > +       .read_string = cputemp_read_string,
> > +       .read = cputemp_read,
> > +};
> > +
> > +static const u32 peci_cputemp_temp_channel_config[] = {
> > +       /* Die temperature */
> > +       HWMON_T_LABEL | HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
> > HWMON_T_CRIT_HYST,
> > +       /* DTS margin */
> > +       HWMON_T_LABEL | HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
> > HWMON_T_CRIT_HYST,
> > +       /* Tcontrol temperature */
> > +       HWMON_T_LABEL | HWMON_T_INPUT | HWMON_T_CRIT,
> > +       /* Tthrottle temperature */
> > +       HWMON_T_LABEL | HWMON_T_INPUT,
> > +       /* Tjmax temperature */
> > +       HWMON_T_LABEL | HWMON_T_INPUT,
> > +       /* Core temperature - for all core channels */
> > +       [channel_core ... CPUTEMP_CHANNEL_NUMS - 1] = HWMON_T_LABEL |
> > HWMON_T_INPUT,
> > +       0
> > +};
> > +
> > +static const struct hwmon_channel_info peci_cputemp_temp_channel = {
> > +       .type = hwmon_temp,
> > +       .config = peci_cputemp_temp_channel_config,
> > +};
> > +
> > +static const struct hwmon_channel_info *peci_cputemp_info[] = {
> > +       &peci_cputemp_temp_channel,
> > +       NULL
> > +};
> > +
> > +static const struct hwmon_chip_info peci_cputemp_chip_info = {
> > +       .ops = &peci_cputemp_ops,
> > +       .info = peci_cputemp_info,
> > +};
> > +
> > +static int peci_cputemp_probe(struct auxiliary_device *adev,
> > +                             const struct auxiliary_device_id *id)
> > +{
> > +       struct device *dev = &adev->dev;
> > +       struct peci_device *peci_dev = to_peci_device(dev->parent);
> > +       struct peci_cputemp *priv;
> > +       struct device *hwmon_dev;
> > +
> > +       priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> > +       if (!priv)
> > +               return -ENOMEM;
> > +
> > +       priv->name = devm_kasprintf(dev, GFP_KERNEL, "peci_cputemp.cpu%d",
> > +                                   peci_dev->info.socket_id);
> > +       if (!priv->name)
> > +               return -ENOMEM;
> > +
> > +       dev_set_drvdata(dev, priv);
>
> What is this used for ?

Our sensors are per-device. We need this to access the corresponding priv in
cputemp_read_string() and cputemp_read().

>
> > +       priv->dev = dev;
> > +       priv->peci_dev = peci_dev;
> > +       priv->gen_info = (const struct cpu_info *)id->driver_data;
> > +
> > +       check_resolved_cores(priv);
> > +
> > +       hwmon_dev = devm_hwmon_device_register_with_info(priv->dev, priv-
> > >name,
> > +                                                        priv,
> > &peci_cputemp_chip_info, NULL);
> > +
> > +       return PTR_ERR_OR_ZERO(hwmon_dev);
> > +}
> > +
> > +static struct resolved_cores_reg resolved_cores_reg_hsx = {
> > +       .bus = 1,
> > +       .dev = 30,
> > +       .func = 3,
> > +       .offset = 0xb4,
> > +};
> > +
> > +static struct resolved_cores_reg resolved_cores_reg_icx = {
> > +       .bus = 14,
> > +       .dev = 30,
> > +       .func = 3,
> > +       .offset = 0xd0,
> > +};
>
> Please explain those magic numbers.
>

Those magic numbers refer to BDF (bus, device, function) and offset of the PCI
config register (RESOLVED_CORES_CFG) that can be accessed via PECI to read
resolved cores configuration.
Unfortunately, the values are just platform-specific magic numbers.
Do you think this should be explained with an additional comment?

Thank you
-Iwona

> > +
> > +static const struct cpu_info cpu_hsx = {
> > +       .reg            = &resolved_cores_reg_hsx,
> > +       .min_peci_revision = 0x30,
> > +};
> > +
> > +static const struct cpu_info cpu_icx = {
> > +       .reg            = &resolved_cores_reg_icx,
> > +       .min_peci_revision = 0x40,
> > +};
> > +
> > +static const struct auxiliary_device_id peci_cputemp_ids[] = {
> > +       {
> > +               .name = "peci_cpu.cputemp.hsx",
> > +               .driver_data = (kernel_ulong_t)&cpu_hsx,
> > +       },
> > +       {
> > +               .name = "peci_cpu.cputemp.bdx",
> > +               .driver_data = (kernel_ulong_t)&cpu_hsx,
> > +       },
> > +       {
> > +               .name = "peci_cpu.cputemp.bdxd",
> > +               .driver_data = (kernel_ulong_t)&cpu_hsx,
> > +       },
> > +       {
> > +               .name = "peci_cpu.cputemp.skx",
> > +               .driver_data = (kernel_ulong_t)&cpu_hsx,
> > +       },
> > +       {
> > +               .name = "peci_cpu.cputemp.icx",
> > +               .driver_data = (kernel_ulong_t)&cpu_icx,
> > +       },
> > +       {
> > +               .name = "peci_cpu.cputemp.icxd",
> > +               .driver_data = (kernel_ulong_t)&cpu_icx,
> > +       },
> > +       { }
> > +};
> > +MODULE_DEVICE_TABLE(auxiliary, peci_cputemp_ids);
> > +
> > +static struct auxiliary_driver peci_cputemp_driver = {
> > +       .probe          = peci_cputemp_probe,
> > +       .id_table       = peci_cputemp_ids,
> > +};
> > +
> > +module_auxiliary_driver(peci_cputemp_driver);
> > +
> > +MODULE_AUTHOR("Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>");
> > +MODULE_AUTHOR("Iwona Winiarska <iwona.winiarska@intel.com>");
> > +MODULE_DESCRIPTION("PECI cputemp driver");
> > +MODULE_LICENSE("GPL");
> > +MODULE_IMPORT_NS(PECI_CPU);