On Tue, 13 Apr 2021, Dale B Stimson <dale.b.stimson@xxxxxxxxx> wrote:
> As part of the System Managemenent Interface (SMI), use the HWMON
> subsystem to display power utilization.
>
> The following standard HWMON power sensors are currently supported
> (and appropriately scaled):
> /sys/class/drm/card0/device/hwmon/hwmon<i>
> - energy1_input
> - power1_cap
> - power1_max
>
> Some non-standard HWMON power information is also provided, such as
> enable bits and intervals.
>
> Signed-off-by: Dale B Stimson <dale.b.stimson@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/Kconfig | 1 +
> drivers/gpu/drm/i915/Makefile | 1 +
> drivers/gpu/drm/i915/i915_drv.c | 9 +
> drivers/gpu/drm/i915/i915_drv.h | 3 +
> drivers/gpu/drm/i915/i915_hwmon.c | 788 ++++++++++++++++++++++++++++++
> drivers/gpu/drm/i915/i915_hwmon.h | 41 ++
> drivers/gpu/drm/i915/i915_reg.h | 53 ++
> 7 files changed, 896 insertions(+)
> create mode 100644 drivers/gpu/drm/i915/i915_hwmon.c
> create mode 100644 drivers/gpu/drm/i915/i915_hwmon.h
>
> diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig
> index 1e1cb245fca77..ec8d5a0d7ea96 100644
> --- a/drivers/gpu/drm/i915/Kconfig
> +++ b/drivers/gpu/drm/i915/Kconfig
> @@ -14,6 +14,7 @@ config DRM_I915
> select DRM_MIPI_DSI
> select RELAY
> select IRQ_WORK
> + select HWMON
> # i915 depends on ACPI_VIDEO when ACPI is enabled
> # but for select to work, need to select ACPI_VIDEO's dependencies, ick
> select BACKLIGHT_CLASS_DEVICE if ACPI
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index d0d936d9137bc..e213e2b129e20 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -37,6 +37,7 @@ i915-y += i915_drv.o \
> i915_config.o \
> i915_irq.o \
> i915_getparam.o \
> + i915_hwmon.o \
> i915_mitigations.o \
> i915_params.o \
> i915_pci.o \
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 305557e1942aa..84c7de3b34c7d 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -69,6 +69,7 @@
>
> #include "i915_debugfs.h"
> #include "i915_drv.h"
> +#include "i915_hwmon.h"
> #include "i915_ioc32.h"
> #include "i915_irq.h"
> #include "i915_memcpy.h"
> @@ -675,6 +676,10 @@ static void i915_driver_register(struct drm_i915_private *dev_priv)
> i915_debugfs_register(dev_priv);
> i915_setup_sysfs(dev_priv);
>
> + /* Register with hwmon */
> + if (i915_hwmon_init(&dev_priv->drm))
Please pass in i915, not struct drm_device.
This is i915_driver_register. Almost all functions being have _register
in them. Why not this one?
> + drm_err(&dev_priv->drm, "Failed to register driver hwmon!\n");
Not sure we want this error message at this level.
> +
> /* Depends on sysfs having been initialized */
> i915_perf_register(dev_priv);
>
> @@ -709,9 +714,13 @@ static void i915_driver_unregister(struct drm_i915_private *dev_priv)
> intel_gt_driver_unregister(&dev_priv->gt);
>
> i915_perf_unregister(dev_priv);
> +
> + i915_hwmon_fini(&dev_priv->drm);
> +
Naming, again _unregister in most places.
> i915_pmu_unregister(dev_priv);
>
> i915_teardown_sysfs(dev_priv);
> +
Stray newline.
> drm_dev_unplug(&dev_priv->drm);
>
> i915_gem_driver_unregister(dev_priv);
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 69e43bf91a153..7e9b452c77e2b 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -61,6 +61,7 @@
> #include <drm/drm_connector.h>
> #include <drm/i915_mei_hdcp_interface.h>
>
> +#include "i915_hwmon.h"
> #include "i915_params.h"
> #include "i915_reg.h"
> #include "i915_utils.h"
> @@ -1109,6 +1110,8 @@ struct drm_i915_private {
>
> struct i915_perf perf;
>
> + struct i915_hwmon hwmon;
> +
> /* Abstract the submission mechanism (legacy ringbuffer or execlists) away */
> struct intel_gt gt;
>
> diff --git a/drivers/gpu/drm/i915/i915_hwmon.c b/drivers/gpu/drm/i915/i915_hwmon.c
> new file mode 100644
> index 0000000000000..ab8f32f7ed1de
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/i915_hwmon.c
> @@ -0,0 +1,788 @@
> +// SPDX-License-Identifier: MIT
> +
Superfluous newline.
> +/*
> + * Copyright © 2020 Intel Corporation
> + */
> +
> +/*
> + * Power-related hwmon entries.
> + */
> +
> +#include <linux/hwmon.h>
> +#include <linux/hwmon-sysfs.h>
> +#include <linux/types.h>
> +
> +#include "i915_drv.h"
> +#include "gt/intel_gt.h"
> +#include "i915_hwmon.h"
> +
> +/*
> + * SF_* - scale factors for particular quantities.
> + * The hwmon standard says that quantities of the given types are specified
> + * in the given units:
> + * - time - milliseconds
> + * - power - microwatts
> + * - energy - microjoules
> + */
> +
> +#define SF_TIME 1000
> +#define SF_POWER 1000000
> +#define SF_ENERGY 1000000
> +
> +static void
> +_locked_with_pm_intel_uncore_rmw(struct intel_uncore *uncore,
> + i915_reg_t reg, u32 clear, u32 set)
> +{
> + struct drm_i915_private *i915 = uncore->i915;
> + struct i915_hwmon *hwmon = &i915->hwmon;
> + 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);
> +}
> +
> +/*
> + * _field_read_and_scale()
Unnecessary if this isn't kernel-doc, and this need not be kernel-doc.
> + * Return type of u64 allows for the case where the scaling might cause a
> + * result exceeding 32 bits.
> + */
> +static __always_inline u64
Why __always_inline? Why not let the compiler decide what makes sense?
> +_field_read_and_scale(struct intel_uncore *uncore, i915_reg_t rgadr,
> + u32 field_msk, int nshift, unsigned int scale_factor)
> +{
> + intel_wakeref_t wakeref;
> + u32 reg_value;
> + u64 scaled_val;
> +
> + with_intel_runtime_pm(uncore->rpm, wakeref)
> + reg_value = intel_uncore_read(uncore, rgadr);
> +
> + reg_value = le32_get_bits(cpu_to_le32(reg_value), field_msk);
> + scaled_val = mul_u32_u32(scale_factor, reg_value);
> +
> + /* Shift, rounding to nearest */
> + if (nshift > 0)
> + scaled_val = (scaled_val + (1 << (nshift - 1))) >> nshift;
> +
> + return scaled_val;
> +}
> +
> +/*
> + * _field_read64_and_scale() - read a 64-bit register and scale.
Ditto for kernel-doc style.
> + */
> +static __always_inline u64
Ditto for __always_inline.
> +_field_read64_and_scale(struct intel_uncore *uncore, i915_reg_t rgadr,
> + u64 field_msk, int nshift, unsigned int scale_factor)
> +{
> + intel_wakeref_t wakeref;
> + u64 reg_value;
> + u64 scaled_val;
> +
> + with_intel_runtime_pm(uncore->rpm, wakeref)
> + reg_value = intel_uncore_read64(uncore, rgadr);
> +
> + reg_value = le64_get_bits(cpu_to_le64(reg_value), field_msk);
> + scaled_val = scale_factor * reg_value;
> +
> + /* Shift, rounding to nearest */
> + if (nshift > 0)
> + scaled_val = (scaled_val + (1 << (nshift - 1))) >> nshift;
> +
> + return scaled_val;
> +}
> +
> +/*
> + * _field_scale_and_write()
> + */
> +static __always_inline void
> +_field_scale_and_write(struct intel_uncore *uncore,
> + 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 = le32_to_cpu(le32_encode_bits(nval, field_msk));
> +
> + _locked_with_pm_intel_uncore_rmw(uncore, rgadr,
> + bits_to_clear, bits_to_set);
> +}
> +
> +/*
> + * i915_energy1_input_show - A custom function to obtain energy1_input.
> + * Use a custom function instead of the usual hwmon helpers in order to
> + * guarantee 64-bits of result to user-space.
> + * Units are microjoules.
> + *
> + * The underlying hardware register is 32-bits and is subject to overflow.
> + * This function compensates for overflow of the 32-bit register by detecting
> + * wrap-around and incrementing an overflow counter.
> + * This only works if the register is sampled often enough to avoid
> + * missing an instance of overflow - achieved either by repeated
> + * queries through the API, or via a possible timer (future - TBD) that
> + * ensures values are read often enough to catch all overflows.
> + *
> + * How long before overflow? For example, with an example scaling bit
> + * shift of 14 bits (see register *PACKAGE_POWER_SKU_UNIT) and a power draw of
> + * 1000 watts, the 32-bit counter will overflow in approximately 4.36 minutes.
> + *
> + * Examples:
> + * 1 watt: (2^32 >> 14) / 1 W / (60 * 60 * 24) secs/day -> 3 days
> + * 1000 watts: (2^32 >> 14) / 1000 W / 60 secs/min -> 4.36 minutes
> + */
> +static ssize_t
> +i915_energy1_input_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + struct drm_i915_private *i915 = dev_get_drvdata(dev);
> + struct intel_uncore *uncore = &i915->uncore;
> + struct i915_hwmon *hwmon = &i915->hwmon;
> + int nshift = hwmon->scl_shift_energy;
> + ssize_t ret;
> + intel_wakeref_t wakeref;
> + u32 reg_value;
> + u64 vlo;
> + u64 vhi;
> +
> + mutex_lock(&hwmon->hwmon_lock);
> +
> + with_intel_runtime_pm(uncore->rpm, wakeref)
> + reg_value = intel_uncore_read(uncore,
> + hwmon->rg.reg_energy_status);
> +
> + /*
> + * The u32 register concatenated with the u32 overflow counter
> + * gives an effective energy counter size of 64-bits. However, the
> + * computations below are done modulo 2^96 to avoid overflow during
> + * scaling in the conversion to microjoules.
> + *
> + * The low-order 64-bits of the resulting quantity are returned to
> + * the caller in units of microjoules, encoded into a decimal string.
> + *
> + * For a power of 1000 watts, 64 bits in units of microjoules will
> + * overflow after 584 years.
> + */
> +
> + if (hwmon->energy_counter_prev > reg_value)
> + hwmon->energy_counter_overflow++;
> +
> + hwmon->energy_counter_prev = reg_value;
> +
> + /*
> + * 64-bit variables vlo and vhi are used for the scaling process.
> + * The 96-bit counter value is composed from the two 64-bit variables
> + * vhi and vlo thusly: counter == vhi << 32 + vlo .
> + * The 32-bits of overlap between the two variables is convenient for
> + * handling overflows out of vlo.
> + */
> +
> + vlo = reg_value;
> + vhi = hwmon->energy_counter_overflow;
> +
> + mutex_unlock(&hwmon->hwmon_lock);
> +
> + vlo = SF_ENERGY * vlo;
> +
> + /* Prepare to round to nearest */
> + if (nshift > 0)
> + vlo += 1 << (nshift - 1);
> +
> + /*
> + * Anything in the upper-32 bits of vlo gets added into vhi here,
> + * and then cleared from vlo.
> + */
> + vhi = (SF_ENERGY * vhi) + (vlo >> 32);
> + vlo &= 0xffffffffULL;
> +
> + /*
> + * Apply the right shift.
> + * - vlo shifted by itself.
> + * - vlo receiving what's shifted out of vhi.
> + * - vhi shifted by itself
> + */
> + vlo = vlo >> nshift;
> + vlo |= (vhi << (32 - nshift)) & 0xffffffffULL;
> + vhi = vhi >> nshift;
> +
> + /* Combined to get a 64-bit result in vlo. */
> + vlo |= (vhi << 32);
> +
> + ret = scnprintf(buf, PAGE_SIZE, "%llu\n", vlo);
sysfs_emit() instead?
> +
> + return ret;
> +}
> +
> +static ssize_t
> +i915_power1_max_enable_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + struct drm_i915_private *i915 = dev_get_drvdata(dev);
> + struct intel_uncore *uncore = &i915->uncore;
> + intel_wakeref_t wakeref;
> + ssize_t ret;
> + u32 reg_value;
> + bool is_enabled;
> +
> + with_intel_runtime_pm(uncore->rpm, wakeref)
> + reg_value = intel_uncore_read(uncore,
> + i915->hwmon.rg.pkg_rapl_limit);
> +
> + is_enabled = !!(reg_value & PKG_PWR_LIM_1_EN);
> +
> + ret = scnprintf(buf, PAGE_SIZE, "%u\n", is_enabled);
> +
> + return ret;
> +}
> +
> +static ssize_t
> +i915_power1_max_enable_store(struct device *dev, struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct drm_i915_private *i915 = dev_get_drvdata(dev);
> + struct intel_uncore *uncore = &i915->uncore;
> + struct i915_hwmon *hwmon = &i915->hwmon;
> + ssize_t ret;
> + u32 val;
> + u32 bits_to_clear;
> + u32 bits_to_set;
> +
> + ret = kstrtou32(buf, 0, &val);
> + if (ret)
> + return ret;
> +
> + bits_to_clear = PKG_PWR_LIM_1_EN;
> + if (!val)
> + bits_to_set = 0;
> + else
> + bits_to_set = PKG_PWR_LIM_1_EN;
> +
> + _locked_with_pm_intel_uncore_rmw(uncore, hwmon->rg.pkg_rapl_limit,
> + bits_to_clear, bits_to_set);
> +
> + return count;
> +}
> +
> +static ssize_t
> +i915_power1_max_interval_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + struct drm_i915_private *i915 = dev_get_drvdata(dev);
> + struct intel_uncore *uncore = &i915->uncore;
> + struct i915_hwmon *hwmon = &i915->hwmon;
> + ssize_t ret;
> + u64 ullval;
> +
> + ullval = _field_read_and_scale(uncore, hwmon->rg.pkg_rapl_limit,
> + PKG_PWR_LIM_1_TIME,
> + hwmon->scl_shift_time, SF_TIME);
> +
> + ret = scnprintf(buf, PAGE_SIZE, "%llu\n", ullval);
> +
> + return ret;
> +}
> +
> +static ssize_t
> +i915_power1_max_interval_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct drm_i915_private *i915 = dev_get_drvdata(dev);
> + struct intel_uncore *uncore = &i915->uncore;
> + struct i915_hwmon *hwmon = &i915->hwmon;
> + ssize_t ret;
> + long val;
> +
> + ret = kstrtoul(buf, 0, &val);
> + if (ret)
> + return ret;
> +
> + _field_scale_and_write(uncore, hwmon->rg.pkg_rapl_limit,
> + PKG_PWR_LIM_2_TIME,
> + hwmon->scl_shift_time, SF_TIME, val);
> +
> + return count;
> +}
> +
> +static ssize_t
> +i915_power1_cap_enable_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + struct drm_i915_private *i915 = dev_get_drvdata(dev);
> + struct intel_uncore *uncore = &i915->uncore;
> + struct i915_hwmon *hwmon = &i915->hwmon;
> + intel_wakeref_t wakeref;
> + ssize_t ret;
> + u32 reg_value;
> + bool is_enabled;
> +
> + with_intel_runtime_pm(uncore->rpm, wakeref)
> + reg_value = intel_uncore_read(uncore,
> + hwmon->rg.pkg_rapl_limit_udw);
> +
> + is_enabled = !!(reg_value & PKG_PWR_LIM_2_EN);
> +
> + ret = scnprintf(buf, PAGE_SIZE, "%u\n", is_enabled);
> +
> + return ret;
> +}
> +
> +static ssize_t
> +i915_power1_cap_enable_store(struct device *dev, struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct drm_i915_private *i915 = dev_get_drvdata(dev);
> + struct intel_uncore *uncore = &i915->uncore;
> + struct i915_hwmon *hwmon = &i915->hwmon;
> + ssize_t ret;
> + u32 val;
> + u32 bits_to_clear;
> + u32 bits_to_set;
> +
> + ret = kstrtou32(buf, 0, &val);
> + if (ret)
> + return ret;
> +
> + bits_to_clear = PKG_PWR_LIM_2_EN;
> + if (!val)
> + bits_to_set = 0;
> + else
> + bits_to_set = PKG_PWR_LIM_2_EN;
> +
> + _locked_with_pm_intel_uncore_rmw(uncore, hwmon->rg.pkg_rapl_limit_udw,
> + bits_to_clear, bits_to_set);
> +
> + return count;
> +}
> +
> +static ssize_t
> +i915_power_default_limit_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + struct drm_i915_private *i915 = dev_get_drvdata(dev);
> + struct i915_hwmon *hwmon = &i915->hwmon;
> + ssize_t ret;
> +
> + ret = scnprintf(buf, PAGE_SIZE, "%u\n", hwmon->power_max_initial_value);
> +
> + return ret;
> +}
> +
> +static ssize_t
> +i915_power_min_limit_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + struct drm_i915_private *i915 = dev_get_drvdata(dev);
> + struct intel_uncore *uncore = &i915->uncore;
> + struct i915_hwmon *hwmon = &i915->hwmon;
> + ssize_t ret;
> + u32 uval;
> +
> + /*
> + * This is a 64-bit register but the individual fields are under 32 bits
> + * in size even after scaling.
> + * The UAPI specifies a size of 32 bits.
> + * The UAPI specifies that 0 should be returned if unsupported.
> + * So, using u32 and %u is sufficient.
> + */
> + if (i915_mmio_reg_valid(hwmon->rg.pkg_power_sku))
> + uval = (u32)_field_read64_and_scale(uncore,
> + hwmon->rg.pkg_power_sku,
> + PKG_MIN_PWR,
> + hwmon->scl_shift_power,
> + SF_POWER);
> + else
> + uval = 0;
> +
> + ret = scnprintf(buf, PAGE_SIZE, "%u\n", uval);
> +
> + return ret;
> +}
> +
> +static ssize_t
> +i915_power_max_limit_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + struct drm_i915_private *i915 = dev_get_drvdata(dev);
> + struct intel_uncore *uncore = &i915->uncore;
> + struct i915_hwmon *hwmon = &i915->hwmon;
> + ssize_t ret;
> + u32 uval;
> +
> + /*
> + * This is a 64-bit register but the individual fields are under 32 bits
> + * in size even after scaling.
> + * The UAPI specifies a size of 32 bits.
> + * The UAPI specifies that UINT_MAX should be returned if unsupported.
> + * So, using u32 and %u is sufficient.
> + */
> + if (i915_mmio_reg_valid(hwmon->rg.pkg_power_sku))
> + uval = (u32)_field_read64_and_scale(uncore,
> + hwmon->rg.pkg_power_sku,
> + PKG_MAX_PWR,
> + hwmon->scl_shift_power,
> + SF_POWER);
> + else
> + uval = UINT_MAX;
> +
> + ret = scnprintf(buf, PAGE_SIZE, "%u\n", uval);
> +
> + return ret;
> +}
> +
> +static SENSOR_DEVICE_ATTR(power1_max_enable, 0664,
> + i915_power1_max_enable_show,
> + i915_power1_max_enable_store, 0);
> +static SENSOR_DEVICE_ATTR(power1_max_interval, 0664,
> + i915_power1_max_interval_show,
> + i915_power1_max_interval_store, 0);
> +static SENSOR_DEVICE_ATTR(power1_cap_enable, 0664,
> + i915_power1_cap_enable_show,
> + i915_power1_cap_enable_store, 0);
> +static SENSOR_DEVICE_ATTR(power_default_limit, 0444,
> + i915_power_default_limit_show, NULL, 0);
> +static SENSOR_DEVICE_ATTR(power_min_limit, 0444,
> + i915_power_min_limit_show, NULL, 0);
> +static SENSOR_DEVICE_ATTR(power_max_limit, 0444,
> + i915_power_max_limit_show, NULL, 0);
> +static SENSOR_DEVICE_ATTR(energy1_input, 0444,
> + i915_energy1_input_show, NULL, 0);
> +
> +static struct attribute *hwmon_attributes[] = {
> + &sensor_dev_attr_power1_max_enable.dev_attr.attr,
> + &sensor_dev_attr_power1_max_interval.dev_attr.attr,
> + &sensor_dev_attr_power1_cap_enable.dev_attr.attr,
> + &sensor_dev_attr_power_default_limit.dev_attr.attr,
> + &sensor_dev_attr_power_min_limit.dev_attr.attr,
> + &sensor_dev_attr_power_max_limit.dev_attr.attr,
> + &sensor_dev_attr_energy1_input.dev_attr.attr,
> + NULL
> +};
> +
> +static umode_t hwmon_attributes_visible(struct kobject *kobj,
> + struct attribute *attr, int index)
> +{
> + struct device *dev = kobj_to_dev(kobj);
> + struct drm_i915_private *i915 = dev_get_drvdata(dev);
> + struct i915_hwmon *hwmon = &i915->hwmon;
> + i915_reg_t rgadr;
> +
> + if (attr == &sensor_dev_attr_energy1_input.dev_attr.attr)
> + rgadr = hwmon->rg.reg_energy_status;
> + else if (attr == &sensor_dev_attr_power1_max_enable.dev_attr.attr)
> + rgadr = hwmon->rg.pkg_rapl_limit;
> + else if (attr == &sensor_dev_attr_power1_max_interval.dev_attr.attr)
> + rgadr = hwmon->rg.pkg_rapl_limit;
> + else if (attr == &sensor_dev_attr_power1_cap_enable.dev_attr.attr)
> + rgadr = hwmon->rg.pkg_rapl_limit_udw;
> + else if (attr == &sensor_dev_attr_power_default_limit.dev_attr.attr)
> + rgadr = hwmon->rg.pkg_rapl_limit;
> + else if (attr == &sensor_dev_attr_power_min_limit.dev_attr.attr)
> + return attr->mode;
> + else if (attr == &sensor_dev_attr_power_max_limit.dev_attr.attr)
> + return attr->mode;
> + else
> + return 0;
> +
> + if (!i915_mmio_reg_valid(rgadr))
> + return 0;
> +
> + return attr->mode;
> +}
> +
> +static const struct attribute_group hwmon_attrgroup = {
> + .attrs = hwmon_attributes,
> + .is_visible = hwmon_attributes_visible,
> +};
> +
> +static const struct attribute_group *hwmon_groups[] = {
> + &hwmon_attrgroup,
> + NULL
> +};
> +
> +/*
> + * HWMON SENSOR TYPE = hwmon_power
> + * - Sustained Power (power1_max)
> + * - Burst power (power1_cap)
> + * - Peak power (power1_crit)
> + */
> +static const u32 i915_config_power[] = {
> + HWMON_P_CAP | HWMON_P_MAX,
> + 0
> +};
> +
> +static const struct hwmon_channel_info i915_power = {
> + .type = hwmon_power,
> + .config = i915_config_power,
> +};
> +
> +static const struct hwmon_channel_info *i915_info[] = {
> + &i915_power,
> + NULL
> +};
> +
> +static umode_t
> +i915_power_is_visible(const struct drm_i915_private *i915, u32 attr, int chan)
> +{
> + i915_reg_t rgadr;
> +
> + switch (attr) {
> + case hwmon_power_max:
> + rgadr = i915->hwmon.rg.pkg_rapl_limit;
> + break;
> + case hwmon_power_cap:
> + rgadr = i915->hwmon.rg.pkg_rapl_limit_udw;
> + break;
> + default:
> + return 0;
> + }
> +
> + if (!i915_mmio_reg_valid(rgadr))
> + return 0;
> +
> + return 0664;
> +}
> +
> +static int
> +i915_power_read(struct drm_i915_private *i915, u32 attr, int chan, long *val)
> +{
> + struct intel_uncore *uncore = &i915->uncore;
> + struct i915_hwmon *hwmon = &i915->hwmon;
> + int ret = 0;
> +
> + switch (attr) {
> + case hwmon_power_max:
> + *val = (long)_field_read_and_scale(uncore,
> + hwmon->rg.pkg_rapl_limit,
> + PKG_PWR_LIM_1,
> + hwmon->scl_shift_power,
> + SF_POWER);
> + break;
> + case hwmon_power_cap:
> + *val = (long)_field_read_and_scale(uncore,
> + hwmon->rg.pkg_rapl_limit_udw,
> + PKG_PWR_LIM_2,
> + hwmon->scl_shift_power,
> + SF_POWER);
> + break;
> + default:
> + ret = -EOPNOTSUPP;
> + }
> +
> + return ret;
> +}
> +
> +static int
> +i915_power_write(struct drm_i915_private *i915, u32 attr, int chan, long val)
> +{
> + struct intel_uncore *uncore = &i915->uncore;
> + struct i915_hwmon *hwmon = &i915->hwmon;
> + int ret = 0;
> +
> + switch (attr) {
> + case hwmon_power_max:
> + _field_scale_and_write(uncore,
> + hwmon->rg.pkg_rapl_limit,
> + PKG_PWR_LIM_1,
> + hwmon->scl_shift_power,
> + SF_POWER, val);
> + break;
> + case hwmon_power_cap:
> + _field_scale_and_write(uncore,
> + hwmon->rg.pkg_rapl_limit_udw,
> + PKG_PWR_LIM_2,
> + hwmon->scl_shift_power,
> + SF_POWER, val);
> + break;
> + default:
> + ret = -EOPNOTSUPP;
> + }
> +
> + return ret;
> +}
> +
> +static umode_t
> +i915_is_visible(const void *data, enum hwmon_sensor_types type,
> + u32 attr, int channel)
> +{
> + struct drm_i915_private *i915 = (struct drm_i915_private *)data;
> +
> + switch (type) {
> + case hwmon_power:
> + return i915_power_is_visible(i915, attr, channel);
> + default:
> + return 0;
> + }
> +}
> +
> +static int
> +i915_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
> + int channel, long *val)
> +{
> + struct drm_i915_private *i915 = kdev_to_i915(dev);
> +
> + switch (type) {
> + case hwmon_power:
> + return i915_power_read(i915, attr, channel, val);
> + default:
> + return -EOPNOTSUPP;
> + }
> +}
> +
> +static int
> +i915_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
> + int channel, long val)
> +{
> + struct drm_i915_private *i915 = kdev_to_i915(dev);
> +
> + switch (type) {
> + case hwmon_power:
> + return i915_power_write(i915, attr, channel, val);
> + default:
> + return -EOPNOTSUPP;
> + }
> +}
> +
> +static const struct hwmon_ops i915_hwmon_ops = {
> + .is_visible = i915_is_visible,
> + .read = i915_read,
> + .write = i915_write,
> +};
> +
> +static const struct hwmon_chip_info i915_chip_info = {
> + .ops = &i915_hwmon_ops,
> + .info = i915_info,
> +};
> +
> +static void
> +i915_hwmon_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;
> + __le32 le_sku_unit;
> +
> + if (IS_DG1(i915)) {
> + hwmon->rg.pkg_power_sku_unit = PCU_PACKAGE_POWER_SKU_UNIT;
> + hwmon->rg.pkg_power_sku = PCU_PACKAGE_POWER_SKU;
> + hwmon->rg.pkg_energy_status = PCU_PACKAGE_ENERGY_STATUS;
> + hwmon->rg.pkg_rapl_limit = PCU_PACKAGE_RAPL_LIMIT;
> + hwmon->rg.pkg_rapl_limit_udw = PCU_PACKAGE_RAPL_LIMIT_UDW;
> + hwmon->rg.plt_energy_status = PCU_PLATFORM_ENERGY_STATUS;
> + } else {
> + hwmon->rg.pkg_power_sku_unit = INVALID_MMIO_REG;
> + hwmon->rg.pkg_power_sku = INVALID_MMIO_REG;
> + hwmon->rg.pkg_energy_status = INVALID_MMIO_REG;
> + hwmon->rg.pkg_rapl_limit = INVALID_MMIO_REG;
> + hwmon->rg.pkg_rapl_limit_udw = INVALID_MMIO_REG;
> + hwmon->rg.plt_energy_status = INVALID_MMIO_REG;
> + }
> +
> + /*
> + * If a platform does not support *_PLATFORM_ENERGY_STATUS,
> + * try *PACKAGE_ENERGY_STATUS.
> + */
> + if (i915_mmio_reg_valid(hwmon->rg.plt_energy_status))
> + hwmon->rg.reg_energy_status = hwmon->rg.plt_energy_status;
> + else
> + hwmon->rg.reg_energy_status = hwmon->rg.pkg_energy_status;
> +
> + wakeref = intel_runtime_pm_get(uncore->rpm);
> +
> + /*
> + * 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->energy_counter_overflow = 0;
> +
> + if (i915_mmio_reg_valid(hwmon->rg.reg_energy_status))
> + hwmon->energy_counter_prev =
> + intel_uncore_read(uncore, hwmon->rg.reg_energy_status);
> + else
> + hwmon->energy_counter_prev = 0;
> +
> + intel_runtime_pm_put(uncore->rpm, wakeref);
> +
> + le_sku_unit = cpu_to_le32(val_sku_unit);
> + hwmon->scl_shift_power = le32_get_bits(le_sku_unit, PKG_PWR_UNIT);
> + hwmon->scl_shift_energy = le32_get_bits(le_sku_unit, PKG_ENERGY_UNIT);
> + hwmon->scl_shift_time = le32_get_bits(le_sku_unit, PKG_TIME_UNIT);
> +
> + /*
> + * There is no direct way to obtain the power default_limit.
> + * The best known workaround is to use the initial value of power1_max.
> + *
> + * The value of power1_max is reset to the default on reboot, but is
> + * not reset by a module unload/load sequence. To allow proper
> + * functioning after a module reload, the value for power1_max is
> + * restored to its original value at module unload time in
> + * i915_hwmon_fini().
> + */
> + hwmon->power_max_initial_value =
> + (u32)_field_read_and_scale(uncore,
> + hwmon->rg.pkg_rapl_limit,
> + PKG_PWR_LIM_1,
> + hwmon->scl_shift_power, SF_POWER);
> +}
> +
> +int i915_hwmon_init(struct drm_device *drm_dev)
> +{
> + struct drm_i915_private *i915 = to_i915(drm_dev);
> + struct i915_hwmon *hwmon = &i915->hwmon;
> + struct device *hwmon_dev;
> +
> + mutex_init(&hwmon->hwmon_lock);
> +
> + i915_hwmon_get_preregistration_info(i915);
> +
> + hwmon_dev = hwmon_device_register_with_info(drm_dev->dev, "i915",
> + drm_dev,
> + &i915_chip_info,
> + hwmon_groups);
> +
> + if (IS_ERR(hwmon_dev)) {
> + mutex_destroy(&hwmon->hwmon_lock);
> + return PTR_ERR(hwmon_dev);
> + }
> +
> + hwmon->dev = hwmon_dev;
> +
> + return 0;
> +}
> +
> +void i915_hwmon_fini(struct drm_device *drm_dev)
> +{
> + struct drm_i915_private *i915 = to_i915(drm_dev);
> + struct i915_hwmon *hwmon = &i915->hwmon;
> +
> + if (hwmon->power_max_initial_value) {
> + /* Restore power1_max. */
> + _field_scale_and_write(&i915->uncore, hwmon->rg.pkg_rapl_limit,
> + PKG_PWR_LIM_1, hwmon->scl_shift_power,
> + SF_POWER,
> + hwmon->power_max_initial_value);
> + }
> +
> + if (hwmon->dev)
> + hwmon_device_unregister(hwmon->dev);
> +
> + mutex_destroy(&hwmon->hwmon_lock);
> +
> + memset(hwmon, 0, sizeof(*hwmon));
> +}
> diff --git a/drivers/gpu/drm/i915/i915_hwmon.h b/drivers/gpu/drm/i915/i915_hwmon.h
> new file mode 100644
> index 0000000000000..0be919f0a463d
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/i915_hwmon.h
> @@ -0,0 +1,41 @@
> +/* SPDX-License-Identifier: MIT */
> +
> +/*
> + * Copyright © 2020 Intel Corporation
> + */
> +
> +#ifndef __INTEL_HWMON_H__
> +#define __INTEL_HWMON_H__
> +
> +#include <drm/drm_device.h>
A forward declaration should be enough. Need <linux/types.h> though.
> +#include "i915_reg.h"
> +
> +struct i915_hwmon_reg {
> + i915_reg_t pkg_power_sku_unit;
> + i915_reg_t pkg_power_sku;
> + i915_reg_t pkg_energy_status;
> + i915_reg_t pkg_rapl_limit;
> + i915_reg_t pkg_rapl_limit_udw;
> + i915_reg_t plt_energy_status;
> + i915_reg_t reg_energy_status;
> +};
> +
> +struct i915_hwmon {
> + struct device *dev;
> + struct mutex hwmon_lock; /* counter overflow logic and rmw */
> +
> + struct i915_hwmon_reg rg;
> +
> + u32 energy_counter_overflow;
> + u32 energy_counter_prev;
> + u32 power_max_initial_value;
> +
> + int scl_shift_power;
> + int scl_shift_energy;
> + int scl_shift_time;
> +};
> +
> +int i915_hwmon_init(struct drm_device *drm_dev);
> +void i915_hwmon_fini(struct drm_device *drm_dev);
> +
> +#endif
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index f80d656331f42..62fccf71ddad6 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -4071,6 +4071,59 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
> #define BXT_RP_STATE_CAP _MMIO(0x138170)
> #define GEN9_RP_STATE_LIMITS _MMIO(0x138148)
>
> +/* DG1 */
> +
> +/* based on MCHBAR_MIRROR_BASE_SNB == 0x140000 */
> +#define PCU_PACKAGE_POWER_SKU_UNIT _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5938)
> +#define PCU_PACKAGE_ENERGY_STATUS _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x593c)
> +#define PCU_PACKAGE_RAPL_LIMIT _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x59a0)
> +#define PCU_PACKAGE_RAPL_LIMIT_UDW _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x59a4)
> +#define PCU_PACKAGE_POWER_SKU INVALID_MMIO_REG
> +#define PCU_PLATFORM_ENERGY_STATUS INVALID_MMIO_REG
> +
> +/* Fields for *_PACKAGE_RAPL_LIMIT: */
> +#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)
> +
> +/*
> + * Fields for *_PACKAGE_RAPL_LIMIT_UDW:
> + * In docs, these fields may be defined relative to the entire 64-bit
> + * register, but here they are defined relative to the 32-bit boundary.
> + */
> +#define PKG_PWR_LIM_2 REG_GENMASK(14, 0) // 46:32
> +#define PKG_PWR_LIM_2_EN REG_BIT(15) // 47:47
> +#define PKG_PWR_LIM_2_TIME REG_GENMASK(23, 17) // 55:49
> +
> +/*
> + * *_PACKAGE_POWER_SKU_UNIT - fields specifying scaling for PCU quantities.
> + * - PKG_PWR_UNIT - Power Units used for power control registers. The
> + * actual unit value is calculated by 1 W / Power(2,PKG_PWR_UNIT).
> + * - PKG_ENERGY_UNIT - Energy Units used for power control registers. The
> + * actual unit value is calculated by 1 J / Power(2,PKG_ENERGY_UNIT).
> + * - PKG_TIME_UNIT - Time Units used for power control registers. The
> + * actual unit value is calculated by 1 s / Power(2,PKG_TIME_UNIT).
> + */
> +#define PKG_PWR_UNIT REG_GENMASK(3, 0)
> +#define PKG_ENERGY_UNIT REG_GENMASK(12, 8)
> +#define PKG_TIME_UNIT REG_GENMASK(19, 16)
> +
> +/*
> + * *_PACKAGE_POWER_SKU - SKU power and timing parameters.
> + * Used herein as a 64-bit bit register.
> + * These masks are defined using GENMASK_ULL as REG_GENMASK is limited to u32
> + * and as GENMASK is "long" and therefore 32-bits on a 32-bit system.
> + * PKG_PKG_TDP, PKG_MIN_PWR, and PKG_MAX_PWR are scaled in the same way as
> + * PKG_PWR_LIM_*, above.
> + * PKG_MAX_WIN has sub-fields for x and y, and has the value: is 1.x * 2^y.
> + */
> +#define PKG_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_Y GENMASK_ULL(54, 53)
> +#define PKG_MAX_WIN_X GENMASK_ULL(52, 48)
> +
> /*
> * Logical Context regs
> */
--
Jani Nikula, Intel Open Source Graphics Center
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