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>
---
.../ABI/testing/sysfs-driver-intel-i915-hwmon | 116 +++
drivers/gpu/drm/i915/Kconfig | 1 +
drivers/gpu/drm/i915/Makefile | 1 +
drivers/gpu/drm/i915/i915_drv.c | 6 +
drivers/gpu/drm/i915/i915_drv.h | 3 +
drivers/gpu/drm/i915/i915_hwmon.c | 757 ++++++++++++++++++
drivers/gpu/drm/i915/i915_hwmon.h | 42 +
drivers/gpu/drm/i915/i915_reg.h | 52 ++
8 files changed, 978 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
create mode 100644 drivers/gpu/drm/i915/i915_hwmon.c
create mode 100644 drivers/gpu/drm/i915/i915_hwmon.h
diff --git a/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon b/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
new file mode 100644
index 0000000000000..2ee7c413ca190
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
@@ -0,0 +1,116 @@
+What: /sys/devices/.../hwmon/hwmon<i>/energy1_input
+Date: June 2021
+KernelVersion: 5.14
+Contact: dri-devel@xxxxxxxxxxxxxxxxxxxxx
+Description:
+ RO. Energy input of device in microjoules.
+
+ The returned textual representation is an unsigned integer
+ number that can be stored in 64-bits. Warning: The hardware
+ register is 32-bits wide and can overflow by wrapping around.
+ A single wrap-around between calls to read this value can
+ be detected and will be accounted for in the returned value.
+ At a power consumption of 1 watt, the 32-bit hardware register
+ would wrap-around approximately every 3 days.
+
+ Only supported for particular Intel i915 graphics platforms.
+
+What: /sys/devices/.../hwmon/hwmon<i>/power1_max_enable
+Date: June 2021
+KernelVersion: 5.14
+Contact: dri-devel@xxxxxxxxxxxxxxxxxxxxx
+Description:
+ RW. Sustained power limit is enabled - true or false.
+
+ The power controller will throttle the operating frequency
+ if the power averaged over a window (typically seconds)
+ exceeds this limit.
+
+ See power1_max_enable power1_max power1_max_interval
+
+ Only supported for particular Intel i915 graphics platforms.
+
+What: /sys/devices/.../hwmon/hwmon<i>/power1_max
+Date: June 2021
+KernelVersion: 5.14
+Contact: dri-devel@xxxxxxxxxxxxxxxxxxxxx
+Description:
+ RW. Sustained power limit in milliwatts
+
+ The power controller will throttle the operating frequency
+ if the power averaged over a window (typically seconds)
+ exceeds this limit.
+
+ See power1_max_enable power1_max power1_max_interval
+
+ Only supported for particular Intel i915 graphics platforms.
+
+What: /sys/devices/.../hwmon/hwmon<i>/power1_max_interval
+Date: June 2021
+KernelVersion: 5.14
+Contact: dri-devel@xxxxxxxxxxxxxxxxxxxxx
+Description:
+ RW. Sustained power limit interval in milliseconds over
+ which sustained power is averaged.
+
+ See power1_max_enable power1_max power1_max_interval
+
+ Only supported for particular Intel i915 graphics platforms.
+
+What: /sys/devices/.../hwmon/hwmon<i>/power1_cap_enable
+Date: June 2021
+KernelVersion: 5.14
+Contact: dri-devel@xxxxxxxxxxxxxxxxxxxxx
+Description:
+ RW. Power burst limit is enabled - true or false
+
+ See power1_cap_enable power1_cap
+
+ Only supported for particular Intel i915 graphics platforms.
+
+What: /sys/devices/.../hwmon/hwmon<i>/power1_cap
+Date: June 2021
+KernelVersion: 5.14
+Contact: dri-devel@xxxxxxxxxxxxxxxxxxxxx
+Description:
+ RW. Power burst limit in milliwatts.
+
+ See power1_cap_enable power1_cap
+
+ Only supported for particular Intel i915 graphics platforms.
+
+What: /sys/devices/.../hwmon/hwmon<i>/power_default_limit
+Date: June 2021
+KernelVersion: 5.14
+Contact: dri-devel@xxxxxxxxxxxxxxxxxxxxx
+Description:
+ RO. Default power limit.
+
+ Only supported for particular Intel i915 graphics platforms.
+
+What: /sys/devices/.../hwmon/hwmon<i>/power_min_limit
+Date: June 2021
+KernelVersion: 5.14
+Contact: dri-devel@xxxxxxxxxxxxxxxxxxxxx
+Description:
+ RO. Default minimum power limit.
+
+ Only supported for particular Intel i915 graphics platforms.
+
+ If not supported, then attribute will be absent, or attempted
+ access will give error return or return value as 0.
+
+What: /sys/devices/.../hwmon/hwmon<i>/power_max_limit
+Date: June 2021
+KernelVersion: 5.14
+Contact: dri-devel@xxxxxxxxxxxxxxxxxxxxx
+Description:
+ RO. Default maximum power limit.
+
+ Only supported for particular Intel i915 graphics platforms.
+
+ If not supported, then one of: absent, error return or value
+ returned as 0 or UINT_MAX.
+
+ If not supported, then attribute will be absent, or attempted
+ access will give error return or return value as 0 or UINT_MAX.
diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig
index 93f4d059fc89f..cd1b9b406c725 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 6947495bf34b8..993c0a9943ef8 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 2f06bb7b3ed2c..3636755622c37 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -70,6 +70,7 @@
#include "i915_debugfs.h"
#include "i915_drv.h"
+#include "i915_hwmon.h"
#include "i915_ioc32.h"
#include "i915_irq.h"
#include "i915_memcpy.h"
@@ -681,6 +682,8 @@ static void i915_driver_register(struct drm_i915_private *dev_priv)
intel_gt_driver_register(&dev_priv->gt);
+ i915_hwmon_register(dev_priv);
+
intel_display_driver_register(dev_priv);
intel_power_domains_enable(dev_priv);
@@ -707,9 +710,12 @@ static void i915_driver_unregister(struct drm_i915_private *dev_priv)
intel_display_driver_unregister(dev_priv);
+ i915_hwmon_unregister(dev_priv);
+
intel_gt_driver_unregister(&dev_priv->gt);
i915_perf_unregister(dev_priv);
+
i915_pmu_unregister(dev_priv);
i915_teardown_sysfs(dev_priv);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 0f6d27da69acd..f0476908e0359 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -60,6 +60,7 @@
#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"
@@ -1118,6 +1119,8 @@ 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..e9e532fcf9d1e
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_hwmon.c
@@ -0,0 +1,757 @@
+// SPDX-License-Identifier: MIT
+/*
+ * 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
+
+#define FIELD_SHIFT(__mask) \
+ (BUILD_BUG_ON_ZERO(!__builtin_constant_p(__mask)) + \
+ BUILD_BUG_ON_ZERO((__mask) == 0) + \
+ __bf_shf(__mask))
+
+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);
+}
+
+/*
+ * 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
+_field_read_and_scale(struct intel_uncore *uncore, i915_reg_t rgadr,
+ u32 field_msk, int field_shift,
+ 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 = (reg_value & field_msk) >> field_shift;
+ 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;
+}
+
+static u64
+_field_read64_and_scale(struct intel_uncore *uncore, i915_reg_t rgadr,
+ u64 field_msk, int field_shift,
+ 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 = (reg_value & field_msk) >> field_shift;
+ scaled_val = scale_factor * reg_value;
+
+ /* Shift, rounding to nearest */
+ if (nshift > 0)
+ scaled_val = (scaled_val + (1 << (nshift - 1))) >> nshift;
+
+ return scaled_val;
+}
+
+static void
+_field_scale_and_write(struct intel_uncore *uncore,
+ i915_reg_t rgadr,
+ u32 field_msk, int field_shift,
+ 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 = (nval << field_shift) | 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.pkg_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 = sysfs_emit(buf, "%llu\n", vlo);
+
+ 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 = sysfs_emit(buf, "%u\n", is_enabled);
+
+ return ret;
+}
+
+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,
+ FIELD_SHIFT(PKG_PWR_LIM_1_TIME),
+ hwmon->scl_shift_time, SF_TIME);
+
+ ret = sysfs_emit(buf, "%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,
+ FIELD_SHIFT(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 = sysfs_emit(buf, "%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 = sysfs_emit(buf, "%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,
+ FIELD_SHIFT(PKG_MIN_PWR),
+ hwmon->scl_shift_power,
+ SF_POWER);
+ else
+ uval = 0;
+
+ ret = sysfs_emit(buf, "%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,
+ FIELD_SHIFT(PKG_MAX_PWR),
+ hwmon->scl_shift_power,
+ SF_POWER);
+ else
+ uval = UINT_MAX;
+
+ ret = sysfs_emit(buf, "%u\n", uval);
+
+ return ret;
+}
+
+static SENSOR_DEVICE_ATTR(power1_max_enable, 0444,
+ i915_power1_max_enable_show, NULL, 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.pkg_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,
+ FIELD_SHIFT(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,
+ FIELD_SHIFT(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,
+ FIELD_SHIFT(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,
+ FIELD_SHIFT(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;
+ } 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;
+ }
+
+ 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.pkg_energy_status))
+ hwmon->energy_counter_prev =
+ intel_uncore_read(uncore, hwmon->rg.pkg_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_unregister().
+ */
+ hwmon->power_max_initial_value =
+ (u32)_field_read_and_scale(uncore,
+ hwmon->rg.pkg_rapl_limit,
+ PKG_PWR_LIM_1,
+ FIELD_SHIFT(PKG_PWR_LIM_1),
+ hwmon->scl_shift_power, SF_POWER);
+}
+
+void i915_hwmon_register(struct drm_i915_private *i915)
+{
+ struct drm_device *drm_dev = &i915->drm;
+ 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);
+ drm_info(&i915->drm, "Failed to register hwmon for i915\n");
+ return;
+ }
+
+ hwmon->dev = hwmon_dev;
+}
+
+void i915_hwmon_unregister(struct drm_i915_private *i915)
+{
+ 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,
+ FIELD_SHIFT(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..2fff4f9a6303f
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_hwmon.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: MIT */
+
+/*
+ * Copyright © 2020 Intel Corporation
+ */
+
+#ifndef __INTEL_HWMON_H__
+#define __INTEL_HWMON_H__
+
+#include <linux/types.h>
+#include <linux/mutex.h>
+#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;
+};
+
+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;
+};
+
+struct drm_i915_private;
+
+void i915_hwmon_register(struct drm_i915_private *i915);
+void i915_hwmon_unregister(struct drm_i915_private *i915);
+
+#endif
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 4979b4965a828..931fdd3a681ac 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -4083,6 +4083,58 @@ 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
+
+/* 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
*/
--
2.31.1
