[Intel-gfx] [PATCH 6/7] drm/i915/hwmon: Expose power1_max_interval

Dixit, Ashutosh ashutosh.dixit at intel.com
Thu Oct 13 15:55:31 UTC 2022


On Mon, 03 Oct 2022 14:32:36 -0700, Andi Shyti wrote:
>

Hi Andi,

> > diff --git a/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon b/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
> > index f9d6d3b08bba..19b9fe3ef237 100644
> > --- a/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
> > +++ b/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
> > @@ -26,6 +26,15 @@ Description:	RO. Card default power limit (default TDP setting).
> >
> >		Only supported for particular Intel i915 graphics platforms.
> >
> > +What:		/sys/devices/.../hwmon/hwmon<i>/power1_max_interval
> > +Date:		February 2023
> > +KernelVersion:	6.2
> > +Contact:	dri-devel at lists.freedesktop.org
>
> same question here.
>
> > +Description:	RW. Sustained power limit interval (Tau in PL1/Tau) in
> > +		milliseconds over which sustained power is averaged.
> > +
> > +		Only supported for particular Intel i915 graphics platforms.
> > +
> >  What:		/sys/devices/.../hwmon/hwmon<i>/power1_crit
> >  Date:		February 2023
> >  KernelVersion:	6.2
> > diff --git a/drivers/gpu/drm/i915/i915_hwmon.c b/drivers/gpu/drm/i915/i915_hwmon.c
> > index 2394fa789793..641143956c45 100644
> > --- a/drivers/gpu/drm/i915/i915_hwmon.c
> > +++ b/drivers/gpu/drm/i915/i915_hwmon.c
> > @@ -20,11 +20,13 @@
> >   * - power  - microwatts
> >   * - curr   - milliamperes
> >   * - energy - microjoules
> > + * - time   - milliseconds
> >   */
> >  #define SF_VOLTAGE	1000
> >  #define SF_POWER	1000000
> >  #define SF_CURR		1000
> >  #define SF_ENERGY	1000000
> > +#define SF_TIME		1000
> >
> >  struct hwm_reg {
> >	i915_reg_t gt_perf_status;
> > @@ -53,6 +55,7 @@ struct i915_hwmon {
> >	struct hwm_reg rg;
> >	int scl_shift_power;
> >	int scl_shift_energy;
> > +	int scl_shift_time;
> >  };
> >
> >  static void
> > @@ -161,6 +164,115 @@ hwm_energy(struct hwm_drvdata *ddat, long *energy)
> >	return 0;
> >  }
> >
> > +static ssize_t
> > +hwm_power1_max_interval_show(struct device *dev, struct device_attribute *attr,
> > +			     char *buf)
> > +{
> > +	struct hwm_drvdata *ddat = dev_get_drvdata(dev);
> > +	struct i915_hwmon *hwmon = ddat->hwmon;
> > +	intel_wakeref_t wakeref;
> > +	u32 r, x, y, x_w = 2; /* 2 bits */
> > +	u64 tau4, out;
> > +
> > +	with_intel_runtime_pm(ddat->uncore->rpm, wakeref)
> > +		r = intel_uncore_read(ddat->uncore, hwmon->rg.pkg_rapl_limit);
> > +
> > +	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
> > +hwm_power1_max_interval_store(struct device *dev,
> > +			      struct device_attribute *attr,
> > +			      const char *buf, size_t count)
> > +{
> > +	struct hwm_drvdata *ddat = dev_get_drvdata(dev);
> > +	struct i915_hwmon *hwmon = ddat->hwmon;
> > +	long val, max_win, ret;
>
> you have some type mismatch here:
>
>  - val should be unsigned long
>  - max_win should be u64
>  - ret should be int

Thanks, fixed in v9.

>
> > +	u32 x, y, rxy, x_w = 2; /* 2 bits */
> > +	u64 tau4, r;
> > +
> > +#define PKG_MAX_WIN_DEFAULT 0x12ull
>
> could you please add a comment here?

Done.

> > +
> > +	ret = kstrtoul(buf, 0, &val);
> > +	if (ret)
> > +		return ret;
> > +
> > +	/*
> > +	 * val must be < max in hwmon interface units. The steps below are
> > +	 * explained in i915_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)
> > +		return -EINVAL;
> > +	y = ilog2(val);
> > +	/* x = (val - (1 << y)) >> (y - 2); */
>
> some leftover

No, it's a comment describing what's happening in the line below. I've left
it as is for now. Can remove it if you think it's unnecessary.

>
> > +	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);
> > +
> > +	hwm_locked_with_pm_intel_uncore_rmw(ddat, hwmon->rg.pkg_rapl_limit,
> > +					    PKG_PWR_LIM_1_TIME, rxy);
> > +	return count;
> > +}
> > +
> > +static SENSOR_DEVICE_ATTR(power1_max_interval, 0664,
> > +			  hwm_power1_max_interval_show,
> > +			  hwm_power1_max_interval_store, 0);
> > +
> > +static struct attribute *hwm_attributes[] = {
> > +	&sensor_dev_attr_power1_max_interval.dev_attr.attr,
> > +	NULL
> > +};
> > +
> > +static umode_t hwm_attributes_visible(struct kobject *kobj,
> > +				      struct attribute *attr, int index)
> > +{
> > +	struct device *dev = kobj_to_dev(kobj);
> > +	struct hwm_drvdata *ddat = dev_get_drvdata(dev);
> > +	struct i915_hwmon *hwmon = ddat->hwmon;
> > +
> > +	if (attr == &sensor_dev_attr_power1_max_interval.dev_attr.attr)
> > +		return i915_mmio_reg_valid(hwmon->rg.pkg_rapl_limit) ? attr->mode : 0;
> > +	else
> > +		return 0;
>
> please remove the else

Done.

Thanks.
--
Ashutosh

> > +}
> > +
> > +static const struct attribute_group hwm_attrgroup = {
> > +	.attrs = hwm_attributes,
> > +	.is_visible = hwm_attributes_visible,
> > +};
> > +
> > +static const struct attribute_group *hwm_groups[] = {
> > +	&hwm_attrgroup,
> > +	NULL
> > +};
> > +
> >  static const struct hwmon_channel_info *hwm_info[] = {
> >	HWMON_CHANNEL_INFO(in, HWMON_I_INPUT),
> >	HWMON_CHANNEL_INFO(power, HWMON_P_MAX | HWMON_P_RATED_MAX | HWMON_P_CRIT),
> > @@ -472,6 +584,7 @@ hwm_get_preregistration_info(struct drm_i915_private *i915)
> >
> >	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);
> >
> >	/*
> >	 * Initialize 'struct hwm_energy_info', i.e. set fields to the
> > @@ -510,7 +623,7 @@ void i915_hwmon_register(struct drm_i915_private *i915)
> >	hwmon_dev = devm_hwmon_device_register_with_info(dev, ddat->name,
> >							 ddat,
> >							 &hwm_chip_info,
> > -							 NULL);
> > +							 hwm_groups);
> >	if (IS_ERR(hwmon_dev)) {
> >		i915->hwmon = NULL;
> >		return;
> > diff --git a/drivers/gpu/drm/i915/intel_mchbar_regs.h b/drivers/gpu/drm/i915/intel_mchbar_regs.h
> > index bd42fb66e297..64aa1e9be463 100644
> > --- a/drivers/gpu/drm/i915/intel_mchbar_regs.h
> > +++ b/drivers/gpu/drm/i915/intel_mchbar_regs.h
> > @@ -194,6 +194,9 @@
> >   */
> >  #define PCU_PACKAGE_POWER_SKU			_MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5930)
> >  #define   PKG_PKG_TDP				GENMASK_ULL(14, 0)
> > +#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_PACKAGE_POWER_SKU_UNIT		_MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5938)
> >  #define   PKG_PWR_UNIT				REG_GENMASK(3, 0)
> > @@ -212,6 +215,10 @@
> >  #define   RPE_MASK				REG_GENMASK(15, 8)
> >  #define PCU_PACKAGE_RAPL_LIMIT			_MMIO(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)
> >
> >  /* snb MCH registers for priority tuning */
> >  #define MCH_SSKPD				_MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5d10)
> > --
> > 2.25.1


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