Commit 727eb1e3 authored by Raag Jadav's avatar Raag Jadav Committed by Anshuman Gupta
Browse files

drm/i915/hwmon: expose fan speed 



Add hwmon support for fan1_input attribute, which will expose fan speed
in RPM. With this in place we can monitor fan speed using lm-sensors tool.

$ sensors
i915-pci-0300
Adapter: PCI adapter
in0:         653.00 mV
fan1:        3833 RPM
power1:           N/A  (max =  43.00 W)
energy1:      32.02 kJ

v2: Handle overflow, add mutex protection and ABI documentation
    Aesthetic adjustments (Riana)
v3: Change rotations data type, ABI date and version
v4: Fix wakeref leak
    Drop switch case and simplify hwm_fan_xx() (Andi)
v5: Rework time calculation, aesthetic adjustments (Andy)
v6: Drop redundant overflow logic (Andy)
    Split fan_input_read() into dedicated helper (Badal)
v7: Fix undefined reference to __udivdi3 for i386 (Andy)

Signed-off-by: default avatarRaag Jadav <raag.jadav@intel.com>
Reviewed-by: default avatarRiana Tauro <riana.tauro@intel.com>
Reviewed-by: default avatarAndi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: default avatarBadal Nilawar <badal.nilawar@intel.com>
Signed-off-by: default avatarAnshuman Gupta <anshuman.gupta@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240823034548.2670032-1-raag.jadav@intel.com
parent 03ded4d4

Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon

+8 −0
Original line number Diff line number Diff line
@@ -75,3 +75,11 @@ Description: RO. Energy input of device or gt in microjoules. 
		for the gt.



		Only supported for particular Intel i915 graphics platforms.



What:		/sys/bus/pci/drivers/i915/.../hwmon/hwmon<i>/fan1_input

Date:		November 2024

KernelVersion:	6.12

Contact:	intel-gfx@lists.freedesktop.org

Description:	RO. Fan speed of device in RPM.



		Only supported for particular Intel i915 graphics platforms.

drivers/gpu/drm/i915/gt/intel_gt_regs.h

+2 −0
Original line number Diff line number Diff line
@@ -1553,6 +1553,8 @@ 
#define VLV_RENDER_C0_COUNT			_MMIO(0x138118)

#define VLV_MEDIA_C0_COUNT			_MMIO(0x13811c)



#define PCU_PWM_FAN_SPEED			_MMIO(0x138140)



#define GEN12_RPSTAT1				_MMIO(0x1381b4)

#define   GEN12_VOLTAGE_MASK			REG_GENMASK(10, 0)

#define   GEN12_CAGF_MASK			REG_GENMASK(19, 11)

drivers/gpu/drm/i915/i915_hwmon.c

+88 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 


#include <linux/hwmon.h>

#include <linux/hwmon-sysfs.h>

#include <linux/jiffies.h>

#include <linux/types.h>



#include "i915_drv.h"
@@ -36,6 +37,7 @@ struct hwm_reg { 
	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 {
@@ -43,11 +45,17 @@ 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;
@@ -276,6 +284,7 @@ static const struct hwmon_channel_info * const hwm_info[] = { 
	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

};
@@ -613,6 +622,69 @@ 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)
@@ -628,6 +700,8 @@ 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;

	}
@@ -648,6 +722,8 @@ 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;

	}
@@ -739,12 +815,14 @@ hwm_get_preregistration_info(struct drm_i915_private *i915) 
		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;

		hwmon->rg.fan_speed = PCU_PWM_FAN_SPEED;

	} 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;

		hwmon->rg.fan_speed = INVALID_MMIO_REG;

	}



	with_intel_runtime_pm(uncore->rpm, wakeref) {
@@ -755,6 +833,16 @@ 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);