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

Nilawar, Badal badal.nilawar at intel.com
Fri Sep 22 09:49:29 UTC 2023



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.

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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