1 files changed, 293 insertions, 62 deletions

diff --git a/drivers/gpu/drm/i915/i915_hwmon.c b/drivers/gpu/drm/i915/i915_hwmon.c
index 1225bc432f0d..7dfe1784153f 100644
--- a/drivers/gpu/drm/i915/i915_hwmon.c
+++ b/drivers/gpu/drm/i915/i915_hwmon.c
@@ -5,7 +5,9 @@
 
 #include <linux/hwmon.h>
 #include <linux/hwmon-sysfs.h>
+#include <linux/jiffies.h>
 #include <linux/types.h>
+#include <linux/units.h>
 
 #include "i915_drv.h"
 #include "i915_hwmon.h"
@@ -31,11 +33,13 @@
 
 struct hwm_reg {
 	i915_reg_t gt_perf_status;
+	i915_reg_t pkg_temp;
 	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;
+	i915_reg_t fan_speed;
 };
 
 struct hwm_energy_info {
@@ -43,13 +47,21 @@ struct hwm_energy_info {
 	long accum_energy;			/* Accumulated energy for energy1_input */
 };
 
+struct hwm_fan_info {
+	u32 reg_val_prev;
+	u64 time_prev;
+};
+
 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 */
+	struct hwm_fan_info fi;			/*  Fan info for fan1_input */
 	char name[12];
 	int gt_n;
+	bool reset_in_progress;
+	wait_queue_head_t waitq;
 };
 
 struct i915_hwmon {
@@ -70,12 +82,13 @@ hwm_locked_with_pm_intel_uncore_rmw(struct hwm_drvdata *ddat,
 	struct intel_uncore *uncore = ddat->uncore;
 	intel_wakeref_t wakeref;
 
-	mutex_lock(&hwmon->hwmon_lock);
+	with_intel_runtime_pm(uncore->rpm, 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);
+		mutex_unlock(&hwmon->hwmon_lock);
+	}
 }
 
 /*
@@ -99,20 +112,6 @@ hwm_field_read_and_scale(struct hwm_drvdata *ddat, i915_reg_t rgadr,
 	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
  *
@@ -148,20 +147,21 @@ hwm_energy(struct hwm_drvdata *ddat, long *energy)
 	else
 		rgaddr = hwmon->rg.energy_status_all;
 
-	mutex_lock(&hwmon->hwmon_lock);
+	with_intel_runtime_pm(uncore->rpm, wakeref) {
+		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;
+		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);
+		*energy = mul_u64_u32_shr(ei->accum_energy, SF_ENERGY,
+					  hwmon->scl_shift_energy);
+		mutex_unlock(&hwmon->hwmon_lock);
+	}
 }
 
 static ssize_t
@@ -187,7 +187,7 @@ hwm_power1_max_interval_show(struct device *dev, struct device_attribute *attr,
 	 *     tau4 = (4 | x) << y
 	 * but add 2 when doing the final right shift to account for units
 	 */
-	tau4 = ((1 << x_w) | x) << y;
+	tau4 = (u64)((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);
 
@@ -223,7 +223,7 @@ hwm_power1_max_interval_store(struct device *dev,
 	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;
+	tau4 = (u64)((1 << x_w) | x) << y;
 	max_win = mul_u64_u32_shr(tau4, SF_TIME, hwmon->scl_shift_time + x_w);
 
 	if (val > max_win)
@@ -232,11 +232,15 @@ hwm_power1_max_interval_store(struct device *dev,
 	/* 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;
+	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);
 
@@ -277,15 +281,17 @@ static const struct attribute_group *hwm_groups[] = {
 	NULL
 };
 
-static const struct hwmon_channel_info *hwm_info[] = {
+static const struct hwmon_channel_info * const hwm_info[] = {
+	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
 	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),
+	HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT),
 	NULL
 };
 
-static const struct hwmon_channel_info *hwm_gt_info[] = {
+static const struct hwmon_channel_info * const hwm_gt_info[] = {
 	HWMON_CHANNEL_INFO(energy, HWMON_E_INPUT),
 	NULL
 };
@@ -308,6 +314,37 @@ static int hwm_pcode_write_i1(struct drm_i915_private *i915, u32 uval)
 }
 
 static umode_t
+hwm_temp_is_visible(const struct hwm_drvdata *ddat, u32 attr)
+{
+	struct i915_hwmon *hwmon = ddat->hwmon;
+
+	if (attr == hwmon_temp_input && i915_mmio_reg_valid(hwmon->rg.pkg_temp))
+		return 0444;
+
+	return 0;
+}
+
+static int
+hwm_temp_read(struct hwm_drvdata *ddat, u32 attr, long *val)
+{
+	struct i915_hwmon *hwmon = ddat->hwmon;
+	intel_wakeref_t wakeref;
+	u32 reg_val;
+
+	switch (attr) {
+	case hwmon_temp_input:
+		with_intel_runtime_pm(ddat->uncore->rpm, wakeref)
+			reg_val = intel_uncore_read(ddat->uncore, hwmon->rg.pkg_temp);
+
+		/* HW register value is in degrees Celsius, convert to millidegrees. */
+		*val = REG_FIELD_GET(TEMP_MASK, reg_val) * MILLIDEGREE_PER_DEGREE;
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static umode_t
 hwm_in_is_visible(const struct hwm_drvdata *ddat, u32 attr)
 {
 	struct drm_i915_private *i915 = ddat->uncore->i915;
@@ -359,6 +396,8 @@ hwm_power_is_visible(const struct hwm_drvdata *ddat, u32 attr, int chan)
 	}
 }
 
+#define PL1_DISABLE 0
+
 /*
  * HW allows arbitrary PL1 limits to be set but silently clamps these values to
  * "typical but not guaranteed" min/max values in rg.pkg_power_sku. Follow the
@@ -372,6 +411,14 @@ hwm_power_max_read(struct hwm_drvdata *ddat, long *val)
 	intel_wakeref_t wakeref;
 	u64 r, min, max;
 
+	/* Check if PL1 limit is disabled */
+	with_intel_runtime_pm(ddat->uncore->rpm, wakeref)
+		r = intel_uncore_read(ddat->uncore, hwmon->rg.pkg_rapl_limit);
+	if (!(r & PKG_PWR_LIM_1_EN)) {
+		*val = PL1_DISABLE;
+		return 0;
+	}
+
 	*val = hwm_field_read_and_scale(ddat,
 					hwmon->rg.pkg_rapl_limit,
 					PKG_PWR_LIM_1,
@@ -392,6 +439,62 @@ hwm_power_max_read(struct hwm_drvdata *ddat, long *val)
 }
 
 static int
+hwm_power_max_write(struct hwm_drvdata *ddat, long val)
+{
+	struct i915_hwmon *hwmon = ddat->hwmon;
+	intel_wakeref_t wakeref;
+	DEFINE_WAIT(wait);
+	int ret = 0;
+	u32 nval;
+
+	/* Block waiting for GuC reset to complete when needed */
+	for (;;) {
+		wakeref = intel_runtime_pm_get(ddat->uncore->rpm);
+		mutex_lock(&hwmon->hwmon_lock);
+
+		prepare_to_wait(&ddat->waitq, &wait, TASK_INTERRUPTIBLE);
+
+		if (!hwmon->ddat.reset_in_progress)
+			break;
+
+		if (signal_pending(current)) {
+			ret = -EINTR;
+			break;
+		}
+
+		mutex_unlock(&hwmon->hwmon_lock);
+		intel_runtime_pm_put(ddat->uncore->rpm, wakeref);
+
+		schedule();
+	}
+	finish_wait(&ddat->waitq, &wait);
+	if (ret)
+		goto exit;
+
+	/* Disable PL1 limit and verify, because the limit cannot be disabled on all platforms */
+	if (val == PL1_DISABLE) {
+		intel_uncore_rmw(ddat->uncore, hwmon->rg.pkg_rapl_limit,
+				 PKG_PWR_LIM_1_EN, 0);
+		nval = intel_uncore_read(ddat->uncore, hwmon->rg.pkg_rapl_limit);
+
+		if (nval & PKG_PWR_LIM_1_EN)
+			ret = -ENODEV;
+		goto exit;
+	}
+
+	/* Computation in 64-bits to avoid overflow. Round to nearest. */
+	nval = DIV_ROUND_CLOSEST_ULL((u64)val << hwmon->scl_shift_power, SF_POWER);
+	nval = PKG_PWR_LIM_1_EN | REG_FIELD_PREP(PKG_PWR_LIM_1, nval);
+
+	intel_uncore_rmw(ddat->uncore, hwmon->rg.pkg_rapl_limit,
+			 PKG_PWR_LIM_1_EN | PKG_PWR_LIM_1, nval);
+exit:
+	mutex_unlock(&hwmon->hwmon_lock);
+	intel_runtime_pm_put(ddat->uncore->rpm, wakeref);
+	return ret;
+}
+
+static int
 hwm_power_read(struct hwm_drvdata *ddat, u32 attr, int chan, long *val)
 {
 	struct i915_hwmon *hwmon = ddat->hwmon;
@@ -425,16 +528,11 @@ hwm_power_read(struct hwm_drvdata *ddat, u32 attr, int chan, long *val)
 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;
+		return hwm_power_max_write(ddat, val);
 	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);
@@ -443,6 +541,41 @@ hwm_power_write(struct hwm_drvdata *ddat, u32 attr, int chan, long val)
 	}
 }
 
+void i915_hwmon_power_max_disable(struct drm_i915_private *i915, bool *old)
+{
+	struct i915_hwmon *hwmon = i915->hwmon;
+	u32 r;
+
+	if (!hwmon || !i915_mmio_reg_valid(hwmon->rg.pkg_rapl_limit))
+		return;
+
+	mutex_lock(&hwmon->hwmon_lock);
+
+	hwmon->ddat.reset_in_progress = true;
+	r = intel_uncore_rmw(hwmon->ddat.uncore, hwmon->rg.pkg_rapl_limit,
+			     PKG_PWR_LIM_1_EN, 0);
+	*old = !!(r & PKG_PWR_LIM_1_EN);
+
+	mutex_unlock(&hwmon->hwmon_lock);
+}
+
+void i915_hwmon_power_max_restore(struct drm_i915_private *i915, bool old)
+{
+	struct i915_hwmon *hwmon = i915->hwmon;
+
+	if (!hwmon || !i915_mmio_reg_valid(hwmon->rg.pkg_rapl_limit))
+		return;
+
+	mutex_lock(&hwmon->hwmon_lock);
+
+	intel_uncore_rmw(hwmon->ddat.uncore, hwmon->rg.pkg_rapl_limit,
+			 PKG_PWR_LIM_1_EN, old ? PKG_PWR_LIM_1_EN : 0);
+	hwmon->ddat.reset_in_progress = false;
+	wake_up_all(&hwmon->ddat.waitq);
+
+	mutex_unlock(&hwmon->hwmon_lock);
+}
+
 static umode_t
 hwm_energy_is_visible(const struct hwm_drvdata *ddat, u32 attr)
 {
@@ -524,12 +657,77 @@ hwm_curr_write(struct hwm_drvdata *ddat, u32 attr, long val)
 }
 
 static umode_t
+hwm_fan_is_visible(const struct hwm_drvdata *ddat, u32 attr)
+{
+	struct i915_hwmon *hwmon = ddat->hwmon;
+
+	if (attr == hwmon_fan_input && i915_mmio_reg_valid(hwmon->rg.fan_speed))
+		return 0444;
+
+	return 0;
+}
+
+static int
+hwm_fan_input_read(struct hwm_drvdata *ddat, long *val)
+{
+	struct i915_hwmon *hwmon = ddat->hwmon;
+	struct hwm_fan_info *fi = &ddat->fi;
+	u64 rotations, time_now, time;
+	intel_wakeref_t wakeref;
+	u32 reg_val;
+	int ret = 0;
+
+	wakeref = intel_runtime_pm_get(ddat->uncore->rpm);
+	mutex_lock(&hwmon->hwmon_lock);
+
+	reg_val = intel_uncore_read(ddat->uncore, hwmon->rg.fan_speed);
+	time_now = get_jiffies_64();
+
+	/*
+	 * HW register value is accumulated count of pulses from
+	 * PWM fan with the scale of 2 pulses per rotation.
+	 */
+	rotations = (reg_val - fi->reg_val_prev) / 2;
+
+	time = jiffies_delta_to_msecs(time_now - fi->time_prev);
+	if (unlikely(!time)) {
+		ret = -EAGAIN;
+		goto exit;
+	}
+
+	/*
+	 * Calculate fan speed in RPM by time averaging two subsequent
+	 * readings in minutes.
+	 * RPM = number of rotations * msecs per minute / time in msecs
+	 */
+	*val = DIV_ROUND_UP_ULL(rotations * (MSEC_PER_SEC * 60), time);
+
+	fi->reg_val_prev = reg_val;
+	fi->time_prev = time_now;
+exit:
+	mutex_unlock(&hwmon->hwmon_lock);
+	intel_runtime_pm_put(ddat->uncore->rpm, wakeref);
+	return ret;
+}
+
+static int
+hwm_fan_read(struct hwm_drvdata *ddat, u32 attr, long *val)
+{
+	if (attr == hwmon_fan_input)
+		return hwm_fan_input_read(ddat, val);
+
+	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_temp:
+		return hwm_temp_is_visible(ddat, attr);
 	case hwmon_in:
 		return hwm_in_is_visible(ddat, attr);
 	case hwmon_power:
@@ -538,6 +736,8 @@ hwm_is_visible(const void *drvdata, enum hwmon_sensor_types type,
 		return hwm_energy_is_visible(ddat, attr);
 	case hwmon_curr:
 		return hwm_curr_is_visible(ddat, attr);
+	case hwmon_fan:
+		return hwm_fan_is_visible(ddat, attr);
 	default:
 		return 0;
 	}
@@ -550,6 +750,8 @@ hwm_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 	struct hwm_drvdata *ddat = dev_get_drvdata(dev);
 
 	switch (type) {
+	case hwmon_temp:
+		return hwm_temp_read(ddat, attr, val);
 	case hwmon_in:
 		return hwm_in_read(ddat, attr, val);
 	case hwmon_power:
@@ -558,6 +760,8 @@ hwm_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 		return hwm_energy_read(ddat, attr, val);
 	case hwmon_curr:
 		return hwm_curr_read(ddat, attr, val);
+	case hwmon_fan:
+		return hwm_fan_read(ddat, attr, val);
 	default:
 		return -EOPNOTSUPP;
 	}
@@ -644,23 +848,21 @@ hwm_get_preregistration_info(struct drm_i915_private *i915)
 	hwmon->rg.gt_perf_status = GEN12_RPSTAT1;
 
 	if (IS_DG1(i915) || IS_DG2(i915)) {
+		hwmon->rg.pkg_temp = PCU_PACKAGE_TEMPERATURE;
 		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;
+		hwmon->rg.fan_speed = PCU_PWM_FAN_SPEED;
 	} else {
+		hwmon->rg.pkg_temp = INVALID_MMIO_REG;
 		hwmon->rg.pkg_power_sku_unit = INVALID_MMIO_REG;
 		hwmon->rg.pkg_power_sku = INVALID_MMIO_REG;
 		hwmon->rg.pkg_rapl_limit = INVALID_MMIO_REG;
 		hwmon->rg.energy_status_all = INVALID_MMIO_REG;
 		hwmon->rg.energy_status_tile = INVALID_MMIO_REG;
+		hwmon->rg.fan_speed = INVALID_MMIO_REG;
 	}
 
 	with_intel_runtime_pm(uncore->rpm, wakeref) {
@@ -671,6 +873,16 @@ hwm_get_preregistration_info(struct drm_i915_private *i915)
 		if (i915_mmio_reg_valid(hwmon->rg.pkg_power_sku_unit))
 			val_sku_unit = intel_uncore_read(uncore,
 							 hwmon->rg.pkg_power_sku_unit);
+
+		/*
+		 * Store the initial fan register value, so that we can use it for
+		 * initial fan speed calculation.
+		 */
+		if (i915_mmio_reg_valid(hwmon->rg.fan_speed)) {
+			ddat->fi.reg_val_prev = intel_uncore_read(uncore,
+								  hwmon->rg.fan_speed);
+			ddat->fi.time_prev = get_jiffies_64();
+		}
 	}
 
 	hwmon->scl_shift_power = REG_FIELD_GET(PKG_PWR_UNIT, val_sku_unit);
@@ -703,7 +915,7 @@ void i915_hwmon_register(struct drm_i915_private *i915)
 	if (!IS_DGFX(i915))
 		return;
 
-	hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
+	hwmon = kzalloc(sizeof(*hwmon), GFP_KERNEL);
 	if (!hwmon)
 		return;
 
@@ -715,6 +927,7 @@ void i915_hwmon_register(struct drm_i915_private *i915)
 	ddat->uncore = &i915->uncore;
 	snprintf(ddat->name, sizeof(ddat->name), "i915");
 	ddat->gt_n = -1;
+	init_waitqueue_head(&ddat->waitq);
 
 	for_each_gt(gt, i915, i) {
 		ddat_gt = hwmon->ddat_gt + i;
@@ -728,14 +941,12 @@ void i915_hwmon_register(struct drm_i915_private *i915)
 	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;
-	}
+	hwmon_dev = hwmon_device_register_with_info(dev, ddat->name,
+						    ddat,
+						    &hwm_chip_info,
+						    hwm_groups);
+	if (IS_ERR(hwmon_dev))
+		goto err;
 
 	ddat->hwmon_dev = hwmon_dev;
 
@@ -748,16 +959,36 @@ void i915_hwmon_register(struct drm_i915_private *i915)
 		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);
+		hwmon_dev = 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;
 	}
+	return;
+err:
+	i915_hwmon_unregister(i915);
 }
 
 void i915_hwmon_unregister(struct drm_i915_private *i915)
 {
-	fetch_and_zero(&i915->hwmon);
+	struct i915_hwmon *hwmon = i915->hwmon;
+	struct intel_gt *gt;
+	int i;
+
+	if (!hwmon)
+		return;
+
+	for_each_gt(gt, i915, i)
+		if (hwmon->ddat_gt[i].hwmon_dev)
+			hwmon_device_unregister(hwmon->ddat_gt[i].hwmon_dev);
+
+	if (hwmon->ddat.hwmon_dev)
+		hwmon_device_unregister(hwmon->ddat.hwmon_dev);
+
+	mutex_destroy(&hwmon->hwmon_lock);
+
+	kfree(i915->hwmon);
+	i915->hwmon = NULL;
 }