Re: [Intel-gfx] [PATCH 3/7] drm/i915/hwmon: Power PL1 limit and TDP setting

["Nilawar, Badal" <badal.nilawar@intel.com>]

On 21-09-2022 17:15, Gupta, Anshuman wrote:
> 
> 
> On 9/16/2022 8:30 PM, Badal Nilawar wrote:
>> From: Dale B Stimson <dale.b.stimson@intel.com>
>>
>> Use i915 HWMON to display/modify dGfx power PL1 limit and TDP setting.
>>
>> v2:
>>    - Fix review comments (Ashutosh)
>>    - Do not restore power1_max upon module unload/load sequence
>>      because on production systems modules are always loaded
>>      and not unloaded/reloaded (Ashutosh)
>>    - Fix review comments (Jani)
>>    - Remove endianness conversion (Ashutosh)
>> v3: Add power1_rated_max (Ashutosh)
>> v4:
>>    - Use macro HWMON_CHANNEL_INFO to define power channel (Guenter)
>>    - Update the date and kernel version in Documentation (Badal)
>> v5: Use hwm_ prefix for static functions (Ashutosh)
>> v6:
>>    - Fix review comments (Ashutosh)
>>    - Update date, kernel version in documentation
>>
>> Cc: Guenter Roeck <linux@roeck-us.net>
>> Signed-off-by: Dale B Stimson <dale.b.stimson@intel.com>
>> Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
>> Signed-off-by: Riana Tauro <riana.tauro@intel.com>
>> Signed-off-by: Badal Nilawar <badal.nilawar@intel.com>
>> Acked-by: Guenter Roeck <linux@roeck-us.net>
>> ---
>>   .../ABI/testing/sysfs-driver-intel-i915-hwmon |  20 +++
>>   drivers/gpu/drm/i915/i915_hwmon.c             | 158 +++++++++++++++++-
>>   drivers/gpu/drm/i915/i915_reg.h               |   5 +
>>   drivers/gpu/drm/i915/intel_mchbar_regs.h      |   6 +
>>   4 files changed, 187 insertions(+), 2 deletions(-)
>>
>> diff --git a/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon 
>> b/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
>> index e2974f928e58..bc061238e35c 100644
>> --- a/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
>> +++ b/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
>> @@ -5,3 +5,23 @@ Contact:    dri-devel@lists.freedesktop.org
>>   Description:    RO. Current Voltage in millivolt.
>>           Only supported for particular Intel i915 graphics platforms.
>> +
>> +What:        /sys/devices/.../hwmon/hwmon<i>/power1_max
>> +Date:        September 2022
>> +KernelVersion:    6
>> +Contact:    dri-devel@lists.freedesktop.org
>> +Description:    RW. Card reactive sustained  (PL1/Tau) power limit in 
>> microwatts.
>> +
>> +        The power controller will throttle the operating frequency
>> +        if the power averaged over a window (typically seconds)
>> +        exceeds this limit.
>> +
>> +        Only supported for particular Intel i915 graphics platforms.
>> +
>> +What:        /sys/devices/.../hwmon/hwmon<i>/power1_rated_max
>> +Date:        September 2022
>> +KernelVersion:    6
>> +Contact:    dri-devel@lists.freedesktop.org
>> +Description:    RO. Card default power limit (default TDP setting).
>> +
>> +        Only supported for particular Intel i915 graphics platforms.
>> diff --git a/drivers/gpu/drm/i915/i915_hwmon.c 
>> b/drivers/gpu/drm/i915/i915_hwmon.c
>> index 45745afa5c5b..5183cf51a49b 100644
>> --- a/drivers/gpu/drm/i915/i915_hwmon.c
>> +++ b/drivers/gpu/drm/i915/i915_hwmon.c
>> @@ -16,11 +16,16 @@
>>   /*
>>    * SF_* - scale factors for particular quantities according to hwmon 
>> spec.
>>    * - voltage  - millivolts
>> + * - power  - microwatts
>>    */
>>   #define SF_VOLTAGE    1000
>> +#define SF_POWER    1000000
>>   struct hwm_reg {
>>       i915_reg_t gt_perf_status;
>> +    i915_reg_t pkg_power_sku_unit;
>> +    i915_reg_t pkg_power_sku;
>> +    i915_reg_t pkg_rapl_limit;
>>   };
>>   struct hwm_drvdata {
>> @@ -34,10 +39,68 @@ struct i915_hwmon {
>>       struct hwm_drvdata ddat;
>>       struct mutex hwmon_lock;        /* counter overflow logic and 
>> rmw */
>>       struct hwm_reg rg;
>> +    int scl_shift_power;
>>   };
>> +static void
>> +hwm_locked_with_pm_intel_uncore_rmw(struct hwm_drvdata *ddat,
>> +                    i915_reg_t reg, u32 clear, u32 set)
>> +{
>> +    struct i915_hwmon *hwmon = ddat->hwmon;
>> +    struct intel_uncore *uncore = ddat->uncore;
>> +    intel_wakeref_t wakeref;
>> +
>> +    mutex_lock(&hwmon->hwmon_lock);
>> +
>> +    with_intel_runtime_pm(uncore->rpm, wakeref)
>> +        intel_uncore_rmw(uncore, reg, clear, set);
>> +
>> +    mutex_unlock(&hwmon->hwmon_lock);
>> +}
>> +
>> +/*
>> + * This function's return type of u64 allows for the case where the 
>> scaling
>> + * of the field taken from the 32-bit register value might cause a 
>> result to
>> + * exceed 32 bits.
>> + */
>> +static u64
>> +hwm_field_read_and_scale(struct hwm_drvdata *ddat, i915_reg_t rgadr,
>> +             u32 field_msk, int nshift, u32 scale_factor)
>> +{
>> +    struct intel_uncore *uncore = ddat->uncore;
>> +    intel_wakeref_t wakeref;
>> +    u32 reg_value;
>> +
>> +    with_intel_runtime_pm(uncore->rpm, wakeref)
>> +        reg_value = intel_uncore_read(uncore, rgadr);
>> +
>> +    reg_value = REG_FIELD_GET(field_msk, reg_value);
>> +
>> +    return mul_u64_u32_shr(reg_value, scale_factor, nshift);
>> +}
>> +
>> +static void
>> +hwm_field_scale_and_write(struct hwm_drvdata *ddat, i915_reg_t rgadr,
>> +              u32 field_msk, int nshift,
>> +              unsigned int scale_factor, long lval)
>> +{
>> +    u32 nval;
>> +    u32 bits_to_clear;
>> +    u32 bits_to_set;
>> +
>> +    /* Computation in 64-bits to avoid overflow. Round to nearest. */
>> +    nval = DIV_ROUND_CLOSEST_ULL((u64)lval << nshift, scale_factor);
>> +
>> +    bits_to_clear = field_msk;
>> +    bits_to_set = FIELD_PREP(field_msk, nval);
>> +
>> +    hwm_locked_with_pm_intel_uncore_rmw(ddat, rgadr,
>> +                        bits_to_clear, bits_to_set);
>> +}
>> +
>>   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),
>>       NULL
>>   };
>> @@ -71,6 +134,64 @@ hwm_in_read(struct hwm_drvdata *ddat, u32 attr, 
>> long *val)
>>       }
>>   }
>> +static umode_t
>> +hwm_power_is_visible(const struct hwm_drvdata *ddat, u32 attr, int chan)
>> +{
>> +    struct i915_hwmon *hwmon = ddat->hwmon;
>> +
>> +    switch (attr) {
>> +    case hwmon_power_max:
>> +        return i915_mmio_reg_valid(hwmon->rg.pkg_rapl_limit) ? 0664 : 0;
>> +    case hwmon_power_rated_max:
>> +        return i915_mmio_reg_valid(hwmon->rg.pkg_power_sku) ? 0444 : 0;
>> +    default:
>> +        return 0;
>> +    }
>> +}
>> +
>> +static int
>> +hwm_power_read(struct hwm_drvdata *ddat, u32 attr, int chan, long *val)
>> +{
>> +    struct i915_hwmon *hwmon = ddat->hwmon;
>> +
>> +    switch (attr) {
>> +    case hwmon_power_max:
>> +        *val = hwm_field_read_and_scale(ddat,
>> +                        hwmon->rg.pkg_rapl_limit,
>> +                        PKG_PWR_LIM_1,
>> +                        hwmon->scl_shift_power,
>> +                        SF_POWER);
>> +        return 0;
>> +    case hwmon_power_rated_max:
>> +        *val = hwm_field_read_and_scale(ddat,
>> +                        hwmon->rg.pkg_power_sku,
>> +                        PKG_PKG_TDP,It seems a dead code, 
>> pkg_power_sky register in initialized with 
> INVALID_MMMIO_REG, why are we exposing this, unless i am missing 
> something ?
Agree that for platforms considered in this series does not support 
hwmon_power_rated_max. In fact hwm_power_is_visible will not allow to 
create sysfs entry if pkg_power_sku is not supported. Considering future 
dgfx platforms we didn't remove this entry. In future for supported 
platforms we just need to assign valid register to pkg_power_sku.

Regards,
Badal
> Br,
> Anshuman.
>> +                        hwmon->scl_shift_power,
>> +                        SF_POWER);
>> +        return 0;
>> +    default:
>> +        return -EOPNOTSUPP;
>> +    }
>> +}
>> +
>> +static int
>> +hwm_power_write(struct hwm_drvdata *ddat, u32 attr, int chan, long val)
>> +{
>> +    struct i915_hwmon *hwmon = ddat->hwmon;
>> +
>> +    switch (attr) {
>> +    case hwmon_power_max:
>> +        hwm_field_scale_and_write(ddat,
>> +                      hwmon->rg.pkg_rapl_limit,
>> +                      PKG_PWR_LIM_1,
>> +                      hwmon->scl_shift_power,
>> +                      SF_POWER, val);
>> +        return 0;
>> +    default:
>> +        return -EOPNOTSUPP;
>> +    }
>> +}
>> +
>>   static umode_t
>>   hwm_is_visible(const void *drvdata, enum hwmon_sensor_types type,
>>              u32 attr, int channel)
>> @@ -80,6 +201,8 @@ hwm_is_visible(const void *drvdata, enum 
>> hwmon_sensor_types type,
>>       switch (type) {
>>       case hwmon_in:
>>           return hwm_in_is_visible(ddat, attr);
>> +    case hwmon_power:
>> +        return hwm_power_is_visible(ddat, attr, channel);
>>       default:
>>           return 0;
>>       }
>> @@ -94,6 +217,8 @@ hwm_read(struct device *dev, enum 
>> hwmon_sensor_types type, u32 attr,
>>       switch (type) {
>>       case hwmon_in:
>>           return hwm_in_read(ddat, attr, val);
>> +    case hwmon_power:
>> +        return hwm_power_read(ddat, attr, channel, val);
>>       default:
>>           return -EOPNOTSUPP;
>>       }
>> @@ -103,7 +228,11 @@ static int
>>   hwm_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
>>         int channel, long val)
>>   {
>> +    struct hwm_drvdata *ddat = dev_get_drvdata(dev);
>> +
>>       switch (type) {
>> +    case hwmon_power:
>> +        return hwm_power_write(ddat, attr, channel, val);
>>       default:
>>           return -EOPNOTSUPP;
>>       }
>> @@ -124,11 +253,36 @@ static void
>>   hwm_get_preregistration_info(struct drm_i915_private *i915)
>>   {
>>       struct i915_hwmon *hwmon = i915->hwmon;
>> +    struct intel_uncore *uncore = &i915->uncore;
>> +    intel_wakeref_t wakeref;
>> +    u32 val_sku_unit;
>> -    if (IS_DG1(i915) || IS_DG2(i915))
>> +    if (IS_DG1(i915) || IS_DG2(i915)) {
>>           hwmon->rg.gt_perf_status = GEN12_RPSTAT1;
>> -    else
>> +        hwmon->rg.pkg_power_sku_unit = PCU_PACKAGE_POWER_SKU_UNIT;
>> +        hwmon->rg.pkg_power_sku = INVALID_MMIO_REG;
>> +        hwmon->rg.pkg_rapl_limit = PCU_PACKAGE_RAPL_LIMIT;
>> +    } else {
>>           hwmon->rg.gt_perf_status = INVALID_MMIO_REG;
>> +        hwmon->rg.pkg_power_sku_unit = INVALID_MMIO_REG;
>> +        hwmon->rg.pkg_power_sku = INVALID_MMIO_REG;
>> +        hwmon->rg.pkg_rapl_limit = INVALID_MMIO_REG;
>> +    }
>> +
>> +    with_intel_runtime_pm(uncore->rpm, wakeref) {
>> +        /*
>> +         * The contents of register hwmon->rg.pkg_power_sku_unit do 
>> not change,
>> +         * so read it once and store the shift values.
>> +         */
>> +        if (i915_mmio_reg_valid(hwmon->rg.pkg_power_sku_unit)) {
>> +            val_sku_unit = intel_uncore_read(uncore,
>> +                             hwmon->rg.pkg_power_sku_unit);
>> +        } else {
>> +            val_sku_unit = 0;
>> +        }
>> +
>> +        hwmon->scl_shift_power = REG_FIELD_GET(PKG_PWR_UNIT, 
>> val_sku_unit);
>> +    }
>>   }
>>   void i915_hwmon_register(struct drm_i915_private *i915)
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h 
>> b/drivers/gpu/drm/i915/i915_reg.h
>> index 1a9bd829fc7e..55c35903adca 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -1807,6 +1807,11 @@
>>   #define   POWER_LIMIT_1_MASK        REG_BIT(10)
>>   #define   POWER_LIMIT_2_MASK        REG_BIT(11)
>> +/*
>> + * *_PACKAGE_POWER_SKU - SKU power and timing parameters.
>> + */
>> +#define   PKG_PKG_TDP            GENMASK_ULL(14, 0)
>> +
>>   #define CHV_CLK_CTL1            _MMIO(0x101100)
>>   #define VLV_CLK_CTL2            _MMIO(0x101104)
>>   #define   CLK_CTL2_CZCOUNT_30NS_SHIFT    28
>> diff --git a/drivers/gpu/drm/i915/intel_mchbar_regs.h 
>> b/drivers/gpu/drm/i915/intel_mchbar_regs.h
>> index ffc702b79579..b74df11977c6 100644
>> --- a/drivers/gpu/drm/i915/intel_mchbar_regs.h
>> +++ b/drivers/gpu/drm/i915/intel_mchbar_regs.h
>> @@ -189,6 +189,10 @@
>>   #define  DG1_QCLK_RATIO_MASK            REG_GENMASK(9, 2)
>>   #define  DG1_QCLK_REFERENCE            REG_BIT(10)
>> +#define PCU_PACKAGE_POWER_SKU_UNIT        
>> _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5938)
>> +#define   PKG_PWR_UNIT                REG_GENMASK(3, 0)
>> +#define   PKG_TIME_UNIT                REG_GENMASK(19, 16)
>> +
>>   #define GEN6_GT_PERF_STATUS            _MMIO(MCHBAR_MIRROR_BASE_SNB 
>> + 0x5948)
>>   #define GEN6_RP_STATE_LIMITS            _MMIO(MCHBAR_MIRROR_BASE_SNB 
>> + 0x5994)
>>   #define GEN6_RP_STATE_CAP            _MMIO(MCHBAR_MIRROR_BASE_SNB + 
>> 0x5998)
>> @@ -198,6 +202,8 @@
>>   #define GEN10_FREQ_INFO_REC            _MMIO(MCHBAR_MIRROR_BASE_SNB 
>> + 0x5ef0)
>>   #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)
>>   /* snb MCH registers for priority tuning */
>>   #define MCH_SSKPD                _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5d10)