Merge tag 'drm-intel-gt-next-2022-11-03' of git://anongit.freedesktop.org/drm/drm-intel into drm-next

Driver Changes:

- Fix for #7306: [Arc A380] white flickering when using arc as a
  secondary gpu (Matt A)
- Add Wa_18017747507 for DG2 (Wayne)
- Avoid spurious WARN on DG1 due to incorrect cache_dirty flag
  (Niranjana, Matt A)
- Corrections to CS timestamp support for Gen5 and earlier (Ville)

- Fix a build error used with clang compiler on hwmon (GG)
- Improvements to LMEM handling with RPM (Anshuman, Matt A)
- Cleanups in dmabuf code (Mike)

- Selftest improvements (Matt A)

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/Y2N11wu175p6qeEN@jlahtine-mobl.ger.corp.intel.com

1 files changed, 732 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_hwmon.c b/drivers/gpu/drm/i915/i915_hwmon.c
new file mode 100644
index 000000000000..c588a17f97e9
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_hwmon.c
@@ -0,0 +1,732 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/types.h>
+
+#include "i915_drv.h"
+#include "i915_hwmon.h"
+#include "i915_reg.h"
+#include "intel_mchbar_regs.h"
+#include "intel_pcode.h"
+#include "gt/intel_gt.h"
+#include "gt/intel_gt_regs.h"
+
+/*
+ * SF_* - scale factors for particular quantities according to hwmon spec.
+ * - voltage  - millivolts
+ * - 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;
+	i915_reg_t pkg_power_sku_unit;
+	i915_reg_t pkg_power_sku;
+	i915_reg_t pkg_rapl_limit;
+	i915_reg_t energy_status_all;
+	i915_reg_t energy_status_tile;
+};
+
+struct hwm_energy_info {
+	u32 reg_val_prev;
+	long accum_energy;			/* Accumulated energy for energy1_input */
+};
+
+struct hwm_drvdata {
+	struct i915_hwmon *hwmon;
+	struct intel_uncore *uncore;
+	struct device *hwmon_dev;
+	struct hwm_energy_info ei;		/*  Energy info for energy1_input */
+	char name[12];
+	int gt_n;
+};
+
+struct i915_hwmon {
+	struct hwm_drvdata ddat;
+	struct hwm_drvdata ddat_gt[I915_MAX_GT];
+	struct mutex hwmon_lock;		/* counter overflow logic and rmw */
+	struct hwm_reg rg;
+	int scl_shift_power;
+	int scl_shift_energy;
+	int scl_shift_time;
+};
+
+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,
+			  int nshift, unsigned int scale_factor, long lval)
+{
+	u32 nval;
+
+	/* Computation in 64-bits to avoid overflow. Round to nearest. */
+	nval = DIV_ROUND_CLOSEST_ULL((u64)lval << nshift, scale_factor);
+
+	hwm_locked_with_pm_intel_uncore_rmw(ddat, rgadr,
+					    PKG_PWR_LIM_1,
+					    REG_FIELD_PREP(PKG_PWR_LIM_1, nval));
+}
+
+/*
+ * hwm_energy - Obtain energy value
+ *
+ * The underlying energy hardware register is 32-bits and is subject to
+ * overflow. 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
+ *
+ * The function significantly increases overflow duration (from 4.36
+ * minutes) by accumulating the energy register into a 'long' as allowed by
+ * the hwmon API. Using x86_64 128 bit arithmetic (see mul_u64_u32_shr()),
+ * a 'long' of 63 bits, SF_ENERGY of 1e6 (~20 bits) and
+ * hwmon->scl_shift_energy of 14 bits we have 57 (63 - 20 + 14) bits before
+ * energy1_input overflows. This at 1000 W is an overflow duration of 278 years.
+ */
+static void
+hwm_energy(struct hwm_drvdata *ddat, long *energy)
+{
+	struct intel_uncore *uncore = ddat->uncore;
+	struct i915_hwmon *hwmon = ddat->hwmon;
+	struct hwm_energy_info *ei = &ddat->ei;
+	intel_wakeref_t wakeref;
+	i915_reg_t rgaddr;
+	u32 reg_val;
+
+	if (ddat->gt_n >= 0)
+		rgaddr = hwmon->rg.energy_status_tile;
+	else
+		rgaddr = hwmon->rg.energy_status_all;
+
+	mutex_lock(&hwmon->hwmon_lock);
+
+	with_intel_runtime_pm(uncore->rpm, wakeref)
+		reg_val = intel_uncore_read(uncore, rgaddr);
+
+	if (reg_val >= ei->reg_val_prev)
+		ei->accum_energy += reg_val - ei->reg_val_prev;
+	else
+		ei->accum_energy += UINT_MAX - ei->reg_val_prev + reg_val;
+	ei->reg_val_prev = reg_val;
+
+	*energy = mul_u64_u32_shr(ei->accum_energy, SF_ENERGY,
+				  hwmon->scl_shift_energy);
+	mutex_unlock(&hwmon->hwmon_lock);
+}
+
+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;
+	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
+
+	/*
+	 * 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); */
+	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;
+
+	return 0;
+}
+
+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),
+	HWMON_CHANNEL_INFO(energy, HWMON_E_INPUT),
+	HWMON_CHANNEL_INFO(curr, HWMON_C_CRIT),
+	NULL
+};
+
+static const struct hwmon_channel_info *hwm_gt_info[] = {
+	HWMON_CHANNEL_INFO(energy, HWMON_E_INPUT),
+	NULL
+};
+
+/* I1 is exposed as power_crit or as curr_crit depending on bit 31 */
+static int hwm_pcode_read_i1(struct drm_i915_private *i915, u32 *uval)
+{
+	return snb_pcode_read_p(&i915->uncore, PCODE_POWER_SETUP,
+				POWER_SETUP_SUBCOMMAND_READ_I1, 0, uval);
+}
+
+static int hwm_pcode_write_i1(struct drm_i915_private *i915, u32 uval)
+{
+	return  snb_pcode_write_p(&i915->uncore, PCODE_POWER_SETUP,
+				  POWER_SETUP_SUBCOMMAND_WRITE_I1, 0, uval);
+}
+
+static umode_t
+hwm_in_is_visible(const struct hwm_drvdata *ddat, u32 attr)
+{
+	struct drm_i915_private *i915 = ddat->uncore->i915;
+
+	switch (attr) {
+	case hwmon_in_input:
+		return IS_DG1(i915) || IS_DG2(i915) ? 0444 : 0;
+	default:
+		return 0;
+	}
+}
+
+static int
+hwm_in_read(struct hwm_drvdata *ddat, u32 attr, long *val)
+{
+	struct i915_hwmon *hwmon = ddat->hwmon;
+	intel_wakeref_t wakeref;
+	u32 reg_value;
+
+	switch (attr) {
+	case hwmon_in_input:
+		with_intel_runtime_pm(ddat->uncore->rpm, wakeref)
+			reg_value = intel_uncore_read(ddat->uncore, hwmon->rg.gt_perf_status);
+		/* HW register value in units of 2.5 millivolt */
+		*val = DIV_ROUND_CLOSEST(REG_FIELD_GET(GEN12_VOLTAGE_MASK, reg_value) * 25, 10);
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static umode_t
+hwm_power_is_visible(const struct hwm_drvdata *ddat, u32 attr, int chan)
+{
+	struct drm_i915_private *i915 = ddat->uncore->i915;
+	struct i915_hwmon *hwmon = ddat->hwmon;
+	u32 uval;
+
+	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;
+	case hwmon_power_crit:
+		return (hwm_pcode_read_i1(i915, &uval) ||
+			!(uval & POWER_SETUP_I1_WATTS)) ? 0 : 0644;
+	default:
+		return 0;
+	}
+}
+
+static int
+hwm_power_read(struct hwm_drvdata *ddat, u32 attr, int chan, long *val)
+{
+	struct i915_hwmon *hwmon = ddat->hwmon;
+	int ret;
+	u32 uval;
+
+	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,
+						hwmon->scl_shift_power,
+						SF_POWER);
+		return 0;
+	case hwmon_power_crit:
+		ret = hwm_pcode_read_i1(ddat->uncore->i915, &uval);
+		if (ret)
+			return ret;
+		if (!(uval & POWER_SETUP_I1_WATTS))
+			return -ENODEV;
+		*val = mul_u64_u32_shr(REG_FIELD_GET(POWER_SETUP_I1_DATA_MASK, uval),
+				       SF_POWER, POWER_SETUP_I1_SHIFT);
+		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;
+	u32 uval;
+
+	switch (attr) {
+	case hwmon_power_max:
+		hwm_field_scale_and_write(ddat,
+					  hwmon->rg.pkg_rapl_limit,
+					  hwmon->scl_shift_power,
+					  SF_POWER, val);
+		return 0;
+	case hwmon_power_crit:
+		uval = DIV_ROUND_CLOSEST_ULL(val << POWER_SETUP_I1_SHIFT, SF_POWER);
+		return hwm_pcode_write_i1(ddat->uncore->i915, uval);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static umode_t
+hwm_energy_is_visible(const struct hwm_drvdata *ddat, u32 attr)
+{
+	struct i915_hwmon *hwmon = ddat->hwmon;
+	i915_reg_t rgaddr;
+
+	switch (attr) {
+	case hwmon_energy_input:
+		if (ddat->gt_n >= 0)
+			rgaddr = hwmon->rg.energy_status_tile;
+		else
+			rgaddr = hwmon->rg.energy_status_all;
+		return i915_mmio_reg_valid(rgaddr) ? 0444 : 0;
+	default:
+		return 0;
+	}
+}
+
+static int
+hwm_energy_read(struct hwm_drvdata *ddat, u32 attr, long *val)
+{
+	switch (attr) {
+	case hwmon_energy_input:
+		hwm_energy(ddat, val);
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static umode_t
+hwm_curr_is_visible(const struct hwm_drvdata *ddat, u32 attr)
+{
+	struct drm_i915_private *i915 = ddat->uncore->i915;
+	u32 uval;
+
+	switch (attr) {
+	case hwmon_curr_crit:
+		return (hwm_pcode_read_i1(i915, &uval) ||
+			(uval & POWER_SETUP_I1_WATTS)) ? 0 : 0644;
+	default:
+		return 0;
+	}
+}
+
+static int
+hwm_curr_read(struct hwm_drvdata *ddat, u32 attr, long *val)
+{
+	int ret;
+	u32 uval;
+
+	switch (attr) {
+	case hwmon_curr_crit:
+		ret = hwm_pcode_read_i1(ddat->uncore->i915, &uval);
+		if (ret)
+			return ret;
+		if (uval & POWER_SETUP_I1_WATTS)
+			return -ENODEV;
+		*val = mul_u64_u32_shr(REG_FIELD_GET(POWER_SETUP_I1_DATA_MASK, uval),
+				       SF_CURR, POWER_SETUP_I1_SHIFT);
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int
+hwm_curr_write(struct hwm_drvdata *ddat, u32 attr, long val)
+{
+	u32 uval;
+
+	switch (attr) {
+	case hwmon_curr_crit:
+		uval = DIV_ROUND_CLOSEST_ULL(val << POWER_SETUP_I1_SHIFT, SF_CURR);
+		return hwm_pcode_write_i1(ddat->uncore->i915, uval);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static umode_t
+hwm_is_visible(const void *drvdata, enum hwmon_sensor_types type,
+	       u32 attr, int channel)
+{
+	struct hwm_drvdata *ddat = (struct hwm_drvdata *)drvdata;
+
+	switch (type) {
+	case hwmon_in:
+		return hwm_in_is_visible(ddat, attr);
+	case hwmon_power:
+		return hwm_power_is_visible(ddat, attr, channel);
+	case hwmon_energy:
+		return hwm_energy_is_visible(ddat, attr);
+	case hwmon_curr:
+		return hwm_curr_is_visible(ddat, attr);
+	default:
+		return 0;
+	}
+}
+
+static int
+hwm_read(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_in:
+		return hwm_in_read(ddat, attr, val);
+	case hwmon_power:
+		return hwm_power_read(ddat, attr, channel, val);
+	case hwmon_energy:
+		return hwm_energy_read(ddat, attr, val);
+	case hwmon_curr:
+		return hwm_curr_read(ddat, attr, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+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);
+	case hwmon_curr:
+		return hwm_curr_write(ddat, attr, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static const struct hwmon_ops hwm_ops = {
+	.is_visible = hwm_is_visible,
+	.read = hwm_read,
+	.write = hwm_write,
+};
+
+static const struct hwmon_chip_info hwm_chip_info = {
+	.ops = &hwm_ops,
+	.info = hwm_info,
+};
+
+static umode_t
+hwm_gt_is_visible(const void *drvdata, enum hwmon_sensor_types type,
+		  u32 attr, int channel)
+{
+	struct hwm_drvdata *ddat = (struct hwm_drvdata *)drvdata;
+
+	switch (type) {
+	case hwmon_energy:
+		return hwm_energy_is_visible(ddat, attr);
+	default:
+		return 0;
+	}
+}
+
+static int
+hwm_gt_read(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_energy:
+		return hwm_energy_read(ddat, attr, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static const struct hwmon_ops hwm_gt_ops = {
+	.is_visible = hwm_gt_is_visible,
+	.read = hwm_gt_read,
+};
+
+static const struct hwmon_chip_info hwm_gt_chip_info = {
+	.ops = &hwm_gt_ops,
+	.info = hwm_gt_info,
+};
+
+static void
+hwm_get_preregistration_info(struct drm_i915_private *i915)
+{
+	struct i915_hwmon *hwmon = i915->hwmon;
+	struct intel_uncore *uncore = &i915->uncore;
+	struct hwm_drvdata *ddat = &hwmon->ddat;
+	intel_wakeref_t wakeref;
+	u32 val_sku_unit = 0;
+	struct intel_gt *gt;
+	long energy;
+	int i;
+
+	/* Available for all Gen12+/dGfx */
+	hwmon->rg.gt_perf_status = GEN12_RPSTAT1;
+
+	if (IS_DG1(i915) || IS_DG2(i915)) {
+		hwmon->rg.pkg_power_sku_unit = PCU_PACKAGE_POWER_SKU_UNIT;
+		hwmon->rg.pkg_power_sku = PCU_PACKAGE_POWER_SKU;
+		hwmon->rg.pkg_rapl_limit = PCU_PACKAGE_RAPL_LIMIT;
+		hwmon->rg.energy_status_all = PCU_PACKAGE_ENERGY_STATUS;
+		hwmon->rg.energy_status_tile = INVALID_MMIO_REG;
+	} else if (IS_XEHPSDV(i915)) {
+		hwmon->rg.pkg_power_sku_unit = GT0_PACKAGE_POWER_SKU_UNIT;
+		hwmon->rg.pkg_power_sku = INVALID_MMIO_REG;
+		hwmon->rg.pkg_rapl_limit = GT0_PACKAGE_RAPL_LIMIT;
+		hwmon->rg.energy_status_all = GT0_PLATFORM_ENERGY_STATUS;
+		hwmon->rg.energy_status_tile = GT0_PACKAGE_ENERGY_STATUS;
+	} else {
+		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;
+		hwmon->rg.energy_status_all = INVALID_MMIO_REG;
+		hwmon->rg.energy_status_tile = 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);
+	}
+
+	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
+	 * first value of the energy register read
+	 */
+	if (i915_mmio_reg_valid(hwmon->rg.energy_status_all))
+		hwm_energy(ddat, &energy);
+	if (i915_mmio_reg_valid(hwmon->rg.energy_status_tile)) {
+		for_each_gt(gt, i915, i)
+			hwm_energy(&hwmon->ddat_gt[i], &energy);
+	}
+}
+
+void i915_hwmon_register(struct drm_i915_private *i915)
+{
+	struct device *dev = i915->drm.dev;
+	struct i915_hwmon *hwmon;
+	struct device *hwmon_dev;
+	struct hwm_drvdata *ddat;
+	struct hwm_drvdata *ddat_gt;
+	struct intel_gt *gt;
+	int i;
+
+	/* hwmon is available only for dGfx */
+	if (!IS_DGFX(i915))
+		return;
+
+	hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
+	if (!hwmon)
+		return;
+
+	i915->hwmon = hwmon;
+	mutex_init(&hwmon->hwmon_lock);
+	ddat = &hwmon->ddat;
+
+	ddat->hwmon = hwmon;
+	ddat->uncore = &i915->uncore;
+	snprintf(ddat->name, sizeof(ddat->name), "i915");
+	ddat->gt_n = -1;
+
+	for_each_gt(gt, i915, i) {
+		ddat_gt = hwmon->ddat_gt + i;
+
+		ddat_gt->hwmon = hwmon;
+		ddat_gt->uncore = gt->uncore;
+		snprintf(ddat_gt->name, sizeof(ddat_gt->name), "i915_gt%u", i);
+		ddat_gt->gt_n = i;
+	}
+
+	hwm_get_preregistration_info(i915);
+
+	/*  hwmon_dev points to device hwmon<i> */
+	hwmon_dev = devm_hwmon_device_register_with_info(dev, ddat->name,
+							 ddat,
+							 &hwm_chip_info,
+							 hwm_groups);
+	if (IS_ERR(hwmon_dev)) {
+		i915->hwmon = NULL;
+		return;
+	}
+
+	ddat->hwmon_dev = hwmon_dev;
+
+	for_each_gt(gt, i915, i) {
+		ddat_gt = hwmon->ddat_gt + i;
+		/*
+		 * Create per-gt directories only if a per-gt attribute is
+		 * visible. Currently this is only energy
+		 */
+		if (!hwm_gt_is_visible(ddat_gt, hwmon_energy, hwmon_energy_input, 0))
+			continue;
+
+		hwmon_dev = devm_hwmon_device_register_with_info(dev, ddat_gt->name,
+								 ddat_gt,
+								 &hwm_gt_chip_info,
+								 NULL);
+		if (!IS_ERR(hwmon_dev))
+			ddat_gt->hwmon_dev = hwmon_dev;
+	}
+}
+
+void i915_hwmon_unregister(struct drm_i915_private *i915)
+{
+	fetch_and_zero(&i915->hwmon);
+}