[Intel-xe] [PATCH v5 6/6] drm/xe/hwmon: Expose power1_max_interval

Ghimiray, Himal Prasad himal.prasad.ghimiray at intel.com
Fri Sep 22 12:43:59 UTC 2023



> -----Original Message-----
> From: Nilawar, Badal <badal.nilawar at intel.com>
> Sent: 22 September 2023 15:19
> To: Ghimiray, Himal Prasad <himal.prasad.ghimiray at intel.com>; intel-
> xe at lists.freedesktop.org; linux-hwmon at vger.kernel.org
> Cc: linux at roeck-us.net; Vivi, Rodrigo <rodrigo.vivi at intel.com>
> Subject: Re: [Intel-xe] [PATCH v5 6/6] drm/xe/hwmon: Expose
> power1_max_interval
> 
> 
> 
> On 21-09-2023 17:13, Ghimiray, Himal Prasad wrote:
> >
> > On 21-09-2023 15:55, Badal Nilawar wrote:
> >> Expose power1_max_interval, that is the tau corresponding to PL1, as
> >> a custom hwmon attribute. Some bit manipulation is needed because of
> >> the format of PKG_PWR_LIM_1_TIME in PACKAGE_RAPL_LIMIT register
> (1.x
> >> * power(2,y))
> >>
> >> v2: Get rpm wake ref while accessing power1_max_interval
> >> v3: %s/hwmon/xe_hwmon/
> >>
> >> Signed-off-by: Badal Nilawar <badal.nilawar at intel.com>
> >> ---
> >>   .../ABI/testing/sysfs-driver-intel-xe-hwmon   |  11 ++
> >>   drivers/gpu/drm/xe/regs/xe_mchbar_regs.h      |   8 +
> >>   drivers/gpu/drm/xe/xe_hwmon.c                 | 138
> >> +++++++++++++++++-
> >>   3 files changed, 156 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon
> >> b/Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon
> >> index 1a7a6c23e141..9ceb9c04b52b 100644
> >> --- a/Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon
> >> +++ b/Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon
> >> @@ -59,3 +59,14 @@ Contact:    intel-xe at lists.freedesktop.org
> >>   Description:    RO. Energy input of device in microjoules.
> >>           Only supported for particular Intel xe graphics platforms.
> >> +
> >> +What:        /sys/devices/.../hwmon/hwmon<i>/power1_max_interval
> >> +Date:        September 2023
> >> +KernelVersion:    6.5
> >> +Contact:    intel-xe at lists.freedesktop.org
> >> +Description:    RW. Sustained power limit interval (Tau in PL1/Tau)
> >> +in
> >> +        milliseconds over which sustained power is averaged.
> >> +
> >> +        Only supported for particular Intel xe graphics platforms.
> >> +
> >> +
> >> diff --git a/drivers/gpu/drm/xe/regs/xe_mchbar_regs.h
> >> b/drivers/gpu/drm/xe/regs/xe_mchbar_regs.h
> >> index d8ecbe1858d1..519dd1067a19 100644
> >> --- a/drivers/gpu/drm/xe/regs/xe_mchbar_regs.h
> >> +++ b/drivers/gpu/drm/xe/regs/xe_mchbar_regs.h
> >> @@ -22,15 +22,23 @@
> >>   #define   PKG_TDP                GENMASK_ULL(14, 0)
> >>   #define   PKG_MIN_PWR                GENMASK_ULL(30, 16)
> >>   #define   PKG_MAX_PWR                GENMASK_ULL(46, 32)
> >> +#define   PKG_MAX_WIN                GENMASK_ULL(54, 48) #define
> >> +PKG_MAX_WIN_X            GENMASK_ULL(54, 53) #define
> >> +PKG_MAX_WIN_Y            GENMASK_ULL(52, 48)
> >> +
> >>   #define PCU_CR_PACKAGE_POWER_SKU_UNIT
> >> XE_REG(MCHBAR_MIRROR_BASE_SNB + 0x5938)
> >>   #define   PKG_PWR_UNIT                REG_GENMASK(3, 0)
> >>   #define   PKG_ENERGY_UNIT            REG_GENMASK(12, 8)
> >> +#define   PKG_TIME_UNIT                REG_GENMASK(19, 16)
> >>   #define PCU_CR_PACKAGE_ENERGY_STATUS
> >> XE_REG(MCHBAR_MIRROR_BASE_SNB + 0x593c)
> >>   #define PCU_CR_PACKAGE_RAPL_LIMIT
> >> XE_REG(MCHBAR_MIRROR_BASE_SNB + 0x59a0)
> >>   #define   PKG_PWR_LIM_1                REG_GENMASK(14, 0)
> >>   #define   PKG_PWR_LIM_1_EN            REG_BIT(15)
> >> +#define   PKG_PWR_LIM_1_TIME            REG_GENMASK(23, 17) #define
> >> +PKG_PWR_LIM_1_TIME_X            REG_GENMASK(23, 22) #define
> >> +PKG_PWR_LIM_1_TIME_Y            REG_GENMASK(21, 17)
> >>   #endif /* _XE_MCHBAR_REGS_H_ */
> >> diff --git a/drivers/gpu/drm/xe/xe_hwmon.c
> >> b/drivers/gpu/drm/xe/xe_hwmon.c index cb75b9a386c0..dfa638942d47
> >> 100644
> >> --- a/drivers/gpu/drm/xe/xe_hwmon.c
> >> +++ b/drivers/gpu/drm/xe/xe_hwmon.c
> >> @@ -38,6 +38,7 @@ enum xe_hwmon_reg_operation {
> >>   #define SF_CURR        1000        /* milliamperes */
> >>   #define SF_VOLTAGE    1000        /* millivolts */
> >>   #define SF_ENERGY    1000000        /* microjoules */
> >> +#define SF_TIME        1000        /* milliseconds */
> >>   struct hwmon_energy_info {
> >>       u32 reg_val_prev;
> >> @@ -50,6 +51,7 @@ struct xe_hwmon {
> >>       struct mutex hwmon_lock; /* rmw operations*/
> >>       int scl_shift_power;
> >>       int scl_shift_energy;
> >> +    int scl_shift_time;
> >>       struct hwmon_energy_info ei;    /*  Energy info for
> >> energy1_input */
> >>   };
> >> @@ -255,6 +257,138 @@ xe_hwmon_energy_get(struct xe_hwmon
> *hwmon,
> >> long
> >> *energy)
> >>       xe_device_mem_access_put(gt_to_xe(hwmon->gt));
> >>   }
> >> +static ssize_t
> >> +xe_hwmon_power1_max_interval_show(struct device *dev, struct
> >> device_attribute *attr,
> >> +                  char *buf)
> >> +{
> >> +    struct xe_hwmon *hwmon = dev_get_drvdata(dev);
> >> +    u32 r, x, y, x_w = 2; /* 2 bits */
> >> +    u64 tau4, out;
> >> +
> >> +    xe_device_mem_access_get(gt_to_xe(hwmon->gt));
> >> +
> >> +    xe_hwmon_process_reg(hwmon, REG_PKG_RAPL_LIMIT,
> >> +                 REG_READ, &r, 0, 0);
> >> +
> >> +    xe_device_mem_access_put(gt_to_xe(hwmon->gt));
> >> +
> >> +    x = REG_FIELD_GET(PKG_PWR_LIM_1_TIME_X, r);
> >> +    y = REG_FIELD_GET(PKG_PWR_LIM_1_TIME_Y, r);
> >> +    /*
> >> +     * tau = 1.x * power(2,y), x = bits(23:22), y = bits(21:17)
> >> +     *     = (4 | x) << (y - 2)
> >> +     * where (y - 2) ensures a 1.x fixed point representation of 1.x
> >> +     * However because y can be < 2, we compute
> >> +     *     tau4 = (4 | x) << y
> >> +     * but add 2 when doing the final right shift to account for
> >> +units
> >> +     */
> >> +    tau4 = ((1 << x_w) | x) << y;
> >> +    /* val in hwmon interface units (millisec) */
> >> +    out = mul_u64_u32_shr(tau4, SF_TIME, hwmon->scl_shift_time +
> >> +x_w);
> >> +
> >> +    return sysfs_emit(buf, "%llu\n", out); }
> >> +
> >> +static ssize_t
> >> +xe_hwmon_power1_max_interval_store(struct device *dev, struct
> >> device_attribute *attr,
> >> +                   const char *buf, size_t count) {
> >> +    struct xe_hwmon *hwmon = dev_get_drvdata(dev);
> >> +    u32 x, y, rxy, x_w = 2; /* 2 bits */
> >> +    u64 tau4, r, max_win;
> >> +    unsigned long val;
> >> +    int ret;
> >> +
> >> +    ret = kstrtoul(buf, 0, &val);
> >> +    if (ret)
> >> +        return ret;
> >> +
> >> +    /*
> >> +     * Max HW supported tau in '1.x * power(2,y)' format, x = 0, y =
> >> 0x12
> >> +     * The hwmon->scl_shift_time default of 0xa results in a max tau
> >> of 256 seconds
> >> +     */
> >> +#define PKG_MAX_WIN_DEFAULT 0x12ull
> >
> > Do we need to determine r, x, y etc for max limit ?
> >
> > Why cant we simply define MAX_LIMIT 256 ?
> PKG_MAX_WIN is field of PKG_PWR_SKU but it is observed that for some
> platforms it is invalid and for some not populated. So fixed the max limit. For
> future platforms if PKG_MAX_WIN is valid then it is prefered to read from
> register, in that case below equation is needed to calculate max limit.

That makes sense. LGTM
Reviewed-by:  Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
> 
> Regards,
> Badal
> >
> > BR
> >
> > Himal
> >
> >> +
> >> +    /*
> >> +     * val must be < max in hwmon interface units. The steps below
> >> +are
> >> +     * explained in xe_hwmon_power1_max_interval_show()
> >> +     */
> >> +    r = FIELD_PREP(PKG_MAX_WIN, PKG_MAX_WIN_DEFAULT);
> >> +    x = REG_FIELD_GET(PKG_MAX_WIN_X, r);
> >> +    y = REG_FIELD_GET(PKG_MAX_WIN_Y, r);
> >> +    tau4 = ((1 << x_w) | x) << y;
> >> +    max_win = mul_u64_u32_shr(tau4, SF_TIME, hwmon->scl_shift_time +
> >> x_w);
> >> +
> >> +    if (val > max_win)
> >> +        return -EINVAL;
> >> +
> >> +    /* val in hw units */
> >> +    val = DIV_ROUND_CLOSEST_ULL((u64)val << hwmon->scl_shift_time,
> >> SF_TIME);
> >> +    /* Convert to 1.x * power(2,y) */
> >> +    if (!val) {
> >> +        /* Avoid ilog2(0) */
> >> +        y = 0;
> >> +        x = 0;
> >> +    } else {
> >> +        y = ilog2(val);
> >> +        /* x = (val - (1 << y)) >> (y - 2); */
> >> +        x = (val - (1ul << y)) << x_w >> y;
> >> +    }
> >> +
> >> +    rxy = REG_FIELD_PREP(PKG_PWR_LIM_1_TIME_X, x) |
> >> REG_FIELD_PREP(PKG_PWR_LIM_1_TIME_Y, y);
> >> +
> >> +    xe_device_mem_access_get(gt_to_xe(hwmon->gt));
> >> +
> >> +    mutex_lock(&hwmon->hwmon_lock);
> >> +
> >> +    xe_hwmon_process_reg(hwmon, REG_PKG_RAPL_LIMIT, REG_RMW,
> (u32
> >> +*)&r,
> >> +                 PKG_PWR_LIM_1_TIME, rxy);
> >> +
> >> +    mutex_unlock(&hwmon->hwmon_lock);
> >> +
> >> +    xe_device_mem_access_put(gt_to_xe(hwmon->gt));
> >> +
> >> +    return count;
> >> +}
> >> +
> >> +static SENSOR_DEVICE_ATTR(power1_max_interval, 0664,
> >> +              xe_hwmon_power1_max_interval_show,
> >> +              xe_hwmon_power1_max_interval_store, 0);
> >> +
> >> +static struct attribute *hwmon_attributes[] = {
> >> +    &sensor_dev_attr_power1_max_interval.dev_attr.attr,
> >> +    NULL
> >> +};
> >> +
> >> +static umode_t xe_hwmon_attributes_visible(struct kobject *kobj,
> >> +                       struct attribute *attr, int index) {
> >> +    struct device *dev = kobj_to_dev(kobj);
> >> +    struct xe_hwmon *hwmon = dev_get_drvdata(dev);
> >> +    u32 reg_val;
> >> +    int ret = 0;
> >> +
> >> +    xe_device_mem_access_get(gt_to_xe(hwmon->gt));
> >> +
> >> +    if (attr == &sensor_dev_attr_power1_max_interval.dev_attr.attr)
> >> +        ret =  xe_hwmon_process_reg(hwmon, REG_PKG_RAPL_LIMIT,
> >> +                        REG_READ, &reg_val, 0, 0) ? 0 : attr->mode;
> >> +
> >> +    xe_device_mem_access_put(gt_to_xe(hwmon->gt));
> >> +
> >> +    return ret;
> >> +}
> >> +
> >> +static const struct attribute_group hwmon_attrgroup = {
> >> +    .attrs = hwmon_attributes,
> >> +    .is_visible = xe_hwmon_attributes_visible, };
> >> +
> >> +static const struct attribute_group *hwmon_groups[] = {
> >> +    &hwmon_attrgroup,
> >> +    NULL
> >> +};
> >> +
> >>   static const struct hwmon_channel_info *hwmon_info[] = {
> >>       HWMON_CHANNEL_INFO(power, HWMON_P_MAX |
> HWMON_P_RATED_MAX |
> >> HWMON_P_CRIT),
> >>       HWMON_CHANNEL_INFO(curr, HWMON_C_CRIT), @@ -573,6 +707,7
> @@
> >> xe_hwmon_get_preregistration_info(struct xe_device
> >> *xe)
> >>       if (!ret) {
> >>           hwmon->scl_shift_power = REG_FIELD_GET(PKG_PWR_UNIT,
> >> val_sku_unit);
> >>           hwmon->scl_shift_energy = REG_FIELD_GET(PKG_ENERGY_UNIT,
> >> val_sku_unit);
> >> +        hwmon->scl_shift_time = REG_FIELD_GET(PKG_TIME_UNIT,
> >> val_sku_unit);
> >>       }
> >>       /*
> >> @@ -612,7 +747,8 @@ void xe_hwmon_register(struct xe_device *xe)
> >>                                   "xe",
> >>                                   hwmon,
> >>                                   &hwmon_chip_info,
> >> -                                NULL);
> >> +                                hwmon_groups);
> >> +
> >>       if (IS_ERR(hwmon->hwmon_dev)) {
> >>           drm_warn(&xe->drm, "Failed to register xe hwmon (%pe)\n",
> >> hwmon->hwmon_dev);
> >>           xe->hwmon = NULL;


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