[PATCH v7] drm/i915/hwmon: expose fan speed
Nilawar, Badal
badal.nilawar at intel.com
Wed Aug 28 05:27:14 UTC 2024
On 23-08-2024 09:15, Raag Jadav wrote:
> 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: Raag Jadav <raag.jadav at intel.com>
> Reviewed-by: Riana Tauro <riana.tauro at intel.com>
> Reviewed-by: Andi Shyti <andi.shyti at linux.intel.com>
> ---
> .../ABI/testing/sysfs-driver-intel-i915-hwmon | 8 ++
> drivers/gpu/drm/i915/gt/intel_gt_regs.h | 2 +
> drivers/gpu/drm/i915/i915_hwmon.c | 88 +++++++++++++++++++
> 3 files changed, 98 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon b/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
> index 92fe7c5c5ac1..be4141a7522f 100644
> --- a/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
> +++ b/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
> @@ -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 at lists.freedesktop.org
> +Description: RO. Fan speed of device in RPM.
> +
> + Only supported for particular Intel i915 graphics platforms.
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> index e42b3a5d4e63..57a3c83d3655 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> @@ -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)
> diff --git a/drivers/gpu/drm/i915/i915_hwmon.c b/drivers/gpu/drm/i915/i915_hwmon.c
> index 49db3e09826c..17d30f6b84b0 100644
> --- a/drivers/gpu/drm/i915/i915_hwmon.c
> +++ b/drivers/gpu/drm/i915/i915_hwmon.c
> @@ -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();
> + }
Reviewed-by: Badal Nilawar <badal.nilawar at intel.com>
> }
>
> hwmon->scl_shift_power = REG_FIELD_GET(PKG_PWR_UNIT, val_sku_unit);
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