[PATCH v3] drm/xe/hwmon: expose fan speed
Rodrigo Vivi
rodrigo.vivi at intel.com
Fri Mar 14 18:09:19 UTC 2025
On Wed, Mar 12, 2025 at 02:29:09PM +0530, Raag Jadav wrote:
> Add hwmon support for fan1_input, fan2_input and fan3_input attributes,
> which will expose fan speed of respective channels in RPM when supported
> by hardware. With this in place we can monitor fan speed using lm-sensors
> tool.
>
> v2: Rely on platform checks instead of mailbox error (Aravind, Rodrigo)
> v3: Introduce has_fan_control flag (Rodrigo)
>
> Signed-off-by: Raag Jadav <raag.jadav at intel.com>
> Reviewed-by: Andi Shyti <andi.shyti at linux.intel.com>
pushed to drm-xe-next, thanks for the patch and reviews
> ---
> .../ABI/testing/sysfs-driver-intel-xe-hwmon | 24 ++++
> drivers/gpu/drm/xe/regs/xe_pcode_regs.h | 3 +
> drivers/gpu/drm/xe/xe_device_types.h | 2 +
> drivers/gpu/drm/xe/xe_hwmon.c | 125 +++++++++++++++++-
> drivers/gpu/drm/xe/xe_pci.c | 4 +
> drivers/gpu/drm/xe/xe_pcode_api.h | 3 +
> 6 files changed, 160 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon b/Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon
> index 9bce281314df..adbb9bce15a5 100644
> --- a/Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon
> +++ b/Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon
> @@ -124,3 +124,27 @@ Contact: intel-xe at lists.freedesktop.org
> Description: RO. VRAM temperature in millidegree Celsius.
>
> Only supported for particular Intel Xe graphics platforms.
> +
> +What: /sys/bus/pci/drivers/xe/.../hwmon/hwmon<i>/fan1_input
> +Date: March 2025
> +KernelVersion: 6.14
> +Contact: intel-xe at lists.freedesktop.org
> +Description: RO. Fan 1 speed in RPM.
> +
> + Only supported for particular Intel Xe graphics platforms.
> +
> +What: /sys/bus/pci/drivers/xe/.../hwmon/hwmon<i>/fan2_input
> +Date: March 2025
> +KernelVersion: 6.14
> +Contact: intel-xe at lists.freedesktop.org
> +Description: RO. Fan 2 speed in RPM.
> +
> + Only supported for particular Intel Xe graphics platforms.
> +
> +What: /sys/bus/pci/drivers/xe/.../hwmon/hwmon<i>/fan3_input
> +Date: March 2025
> +KernelVersion: 6.14
> +Contact: intel-xe at lists.freedesktop.org
> +Description: RO. Fan 3 speed in RPM.
> +
> + Only supported for particular Intel Xe graphics platforms.
> diff --git a/drivers/gpu/drm/xe/regs/xe_pcode_regs.h b/drivers/gpu/drm/xe/regs/xe_pcode_regs.h
> index 8846eb9ce2a4..c7d5d782e3f9 100644
> --- a/drivers/gpu/drm/xe/regs/xe_pcode_regs.h
> +++ b/drivers/gpu/drm/xe/regs/xe_pcode_regs.h
> @@ -21,6 +21,9 @@
> #define BMG_PACKAGE_POWER_SKU XE_REG(0x138098)
> #define BMG_PACKAGE_POWER_SKU_UNIT XE_REG(0x1380dc)
> #define BMG_PACKAGE_ENERGY_STATUS XE_REG(0x138120)
> +#define BMG_FAN_1_SPEED XE_REG(0x138140)
> +#define BMG_FAN_2_SPEED XE_REG(0x138170)
> +#define BMG_FAN_3_SPEED XE_REG(0x1381a0)
> #define BMG_VRAM_TEMPERATURE XE_REG(0x1382c0)
> #define BMG_PACKAGE_TEMPERATURE XE_REG(0x138434)
> #define BMG_PACKAGE_RAPL_LIMIT XE_REG(0x138440)
> diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
> index 833c29fed3a3..6bde5b5e45f9 100644
> --- a/drivers/gpu/drm/xe/xe_device_types.h
> +++ b/drivers/gpu/drm/xe/xe_device_types.h
> @@ -300,6 +300,8 @@ struct xe_device {
> u8 has_atomic_enable_pte_bit:1;
> /** @info.has_device_atomics_on_smem: Supports device atomics on SMEM */
> u8 has_device_atomics_on_smem:1;
> + /** @info.has_fan_control: Device supports fan control */
> + u8 has_fan_control:1;
> /** @info.has_flat_ccs: Whether flat CCS metadata is used */
> u8 has_flat_ccs:1;
> /** @info.has_heci_cscfi: device has heci cscfi */
> diff --git a/drivers/gpu/drm/xe/xe_hwmon.c b/drivers/gpu/drm/xe/xe_hwmon.c
> index 48d80ffdf7bb..eb293aec36a0 100644
> --- a/drivers/gpu/drm/xe/xe_hwmon.c
> +++ b/drivers/gpu/drm/xe/xe_hwmon.c
> @@ -5,6 +5,7 @@
>
> #include <linux/hwmon-sysfs.h>
> #include <linux/hwmon.h>
> +#include <linux/jiffies.h>
> #include <linux/types.h>
> #include <linux/units.h>
>
> @@ -27,6 +28,7 @@ enum xe_hwmon_reg {
> REG_PKG_POWER_SKU_UNIT,
> REG_GT_PERF_STATUS,
> REG_PKG_ENERGY_STATUS,
> + REG_FAN_SPEED,
> };
>
> enum xe_hwmon_reg_operation {
> @@ -42,6 +44,13 @@ enum xe_hwmon_channel {
> CHANNEL_MAX,
> };
>
> +enum xe_fan_channel {
> + FAN_1,
> + FAN_2,
> + FAN_3,
> + FAN_MAX,
> +};
> +
> /*
> * SF_* - scale factors for particular quantities according to hwmon spec.
> */
> @@ -61,6 +70,16 @@ struct xe_hwmon_energy_info {
> long accum_energy;
> };
>
> +/**
> + * struct xe_hwmon_fan_info - to cache previous fan reading
> + */
> +struct xe_hwmon_fan_info {
> + /** @reg_val_prev: previous fan reg val */
> + u32 reg_val_prev;
> + /** @time_prev: previous timestamp */
> + u64 time_prev;
> +};
> +
> /**
> * struct xe_hwmon - xe hwmon data structure
> */
> @@ -79,6 +98,8 @@ struct xe_hwmon {
> int scl_shift_time;
> /** @ei: Energy info for energyN_input */
> struct xe_hwmon_energy_info ei[CHANNEL_MAX];
> + /** @fi: Fan info for fanN_input */
> + struct xe_hwmon_fan_info fi[FAN_MAX];
> };
>
> static struct xe_reg xe_hwmon_get_reg(struct xe_hwmon *hwmon, enum xe_hwmon_reg hwmon_reg,
> @@ -144,6 +165,14 @@ static struct xe_reg xe_hwmon_get_reg(struct xe_hwmon *hwmon, enum xe_hwmon_reg
> return PCU_CR_PACKAGE_ENERGY_STATUS;
> }
> break;
> + case REG_FAN_SPEED:
> + if (channel == FAN_1)
> + return BMG_FAN_1_SPEED;
> + else if (channel == FAN_2)
> + return BMG_FAN_2_SPEED;
> + else if (channel == FAN_3)
> + return BMG_FAN_3_SPEED;
> + break;
> default:
> drm_warn(&xe->drm, "Unknown xe hwmon reg id: %d\n", hwmon_reg);
> break;
> @@ -454,6 +483,7 @@ static const struct hwmon_channel_info * const hwmon_info[] = {
> HWMON_CHANNEL_INFO(curr, HWMON_C_LABEL, HWMON_C_CRIT | HWMON_C_LABEL),
> HWMON_CHANNEL_INFO(in, HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL),
> HWMON_CHANNEL_INFO(energy, HWMON_E_INPUT | HWMON_E_LABEL, HWMON_E_INPUT | HWMON_E_LABEL),
> + HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT, HWMON_F_INPUT, HWMON_F_INPUT),
> NULL
> };
>
> @@ -480,6 +510,19 @@ static int xe_hwmon_pcode_write_i1(const struct xe_hwmon *hwmon, u32 uval)
> (uval & POWER_SETUP_I1_DATA_MASK));
> }
>
> +static int xe_hwmon_pcode_read_fan_control(const struct xe_hwmon *hwmon, u32 subcmd, u32 *uval)
> +{
> + struct xe_tile *root_tile = xe_device_get_root_tile(hwmon->xe);
> +
> + /* Platforms that don't return correct value */
> + if (hwmon->xe->info.platform == XE_DG2 && subcmd == FSC_READ_NUM_FANS) {
> + *uval = 2;
> + return 0;
> + }
> +
> + return xe_pcode_read(root_tile, PCODE_MBOX(FAN_SPEED_CONTROL, subcmd, 0), uval, NULL);
> +}
> +
> static int xe_hwmon_power_curr_crit_read(struct xe_hwmon *hwmon, int channel,
> long *value, u32 scale_factor)
> {
> @@ -705,6 +748,75 @@ xe_hwmon_energy_read(struct xe_hwmon *hwmon, u32 attr, int channel, long *val)
> }
> }
>
> +static umode_t
> +xe_hwmon_fan_is_visible(struct xe_hwmon *hwmon, u32 attr, int channel)
> +{
> + u32 uval;
> +
> + if (!hwmon->xe->info.has_fan_control)
> + return 0;
> +
> + switch (attr) {
> + case hwmon_fan_input:
> + if (xe_hwmon_pcode_read_fan_control(hwmon, FSC_READ_NUM_FANS, &uval))
> + return 0;
> +
> + return channel < uval ? 0444 : 0;
> + default:
> + return 0;
> + }
> +}
> +
> +static int
> +xe_hwmon_fan_input_read(struct xe_hwmon *hwmon, int channel, long *val)
> +{
> + struct xe_mmio *mmio = xe_root_tile_mmio(hwmon->xe);
> + struct xe_hwmon_fan_info *fi = &hwmon->fi[channel];
> + u64 rotations, time_now, time;
> + u32 reg_val;
> + int ret = 0;
> +
> + mutex_lock(&hwmon->hwmon_lock);
> +
> + reg_val = xe_mmio_read32(mmio, xe_hwmon_get_reg(hwmon, REG_FAN_SPEED, channel));
> + 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 unlock;
> + }
> +
> + /*
> + * 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;
> +unlock:
> + mutex_unlock(&hwmon->hwmon_lock);
> + return ret;
> +}
> +
> +static int
> +xe_hwmon_fan_read(struct xe_hwmon *hwmon, u32 attr, int channel, long *val)
> +{
> + switch (attr) {
> + case hwmon_fan_input:
> + return xe_hwmon_fan_input_read(hwmon, channel, val);
> + default:
> + return -EOPNOTSUPP;
> + }
> +}
> +
> static umode_t
> xe_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_types type,
> u32 attr, int channel)
> @@ -730,6 +842,9 @@ xe_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_types type,
> case hwmon_energy:
> ret = xe_hwmon_energy_is_visible(hwmon, attr, channel);
> break;
> + case hwmon_fan:
> + ret = xe_hwmon_fan_is_visible(hwmon, attr, channel);
> + break;
> default:
> ret = 0;
> break;
> @@ -765,6 +880,9 @@ xe_hwmon_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
> case hwmon_energy:
> ret = xe_hwmon_energy_read(hwmon, attr, channel, val);
> break;
> + case hwmon_fan:
> + ret = xe_hwmon_fan_read(hwmon, attr, channel, val);
> + break;
> default:
> ret = -EOPNOTSUPP;
> break;
> @@ -842,7 +960,7 @@ static void
> xe_hwmon_get_preregistration_info(struct xe_hwmon *hwmon)
> {
> struct xe_mmio *mmio = xe_root_tile_mmio(hwmon->xe);
> - long energy;
> + long energy, fan_speed;
> u64 val_sku_unit = 0;
> int channel;
> struct xe_reg pkg_power_sku_unit;
> @@ -866,6 +984,11 @@ xe_hwmon_get_preregistration_info(struct xe_hwmon *hwmon)
> for (channel = 0; channel < CHANNEL_MAX; channel++)
> if (xe_hwmon_is_visible(hwmon, hwmon_energy, hwmon_energy_input, channel))
> xe_hwmon_energy_get(hwmon, channel, &energy);
> +
> + /* Initialize 'struct xe_hwmon_fan_info' with initial fan register reading. */
> + for (channel = 0; channel < FAN_MAX; channel++)
> + if (xe_hwmon_is_visible(hwmon, hwmon_fan, hwmon_fan_input, channel))
> + xe_hwmon_fan_input_read(hwmon, channel, &fan_speed);
> }
>
> static void xe_hwmon_mutex_destroy(void *arg)
> diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c
> index 8b6658b214be..2eaee2476c65 100644
> --- a/drivers/gpu/drm/xe/xe_pci.c
> +++ b/drivers/gpu/drm/xe/xe_pci.c
> @@ -62,6 +62,7 @@ struct xe_device_desc {
> u8 is_dgfx:1;
>
> u8 has_display:1;
> + u8 has_fan_control:1;
> u8 has_heci_gscfi:1;
> u8 has_heci_cscfi:1;
> u8 has_llc:1;
> @@ -322,6 +323,7 @@ static const struct xe_device_desc dg2_desc = {
>
> DG2_FEATURES,
> .has_display = true,
> + .has_fan_control = true,
> };
>
> static const __maybe_unused struct xe_device_desc pvc_desc = {
> @@ -356,6 +358,7 @@ static const struct xe_device_desc bmg_desc = {
> PLATFORM(BATTLEMAGE),
> .dma_mask_size = 46,
> .has_display = true,
> + .has_fan_control = true,
> .has_heci_cscfi = 1,
> };
>
> @@ -631,6 +634,7 @@ static int xe_info_init_early(struct xe_device *xe,
>
> xe->info.dma_mask_size = desc->dma_mask_size;
> xe->info.is_dgfx = desc->is_dgfx;
> + xe->info.has_fan_control = desc->has_fan_control;
> xe->info.has_heci_gscfi = desc->has_heci_gscfi;
> xe->info.has_heci_cscfi = desc->has_heci_cscfi;
> xe->info.has_llc = desc->has_llc;
> diff --git a/drivers/gpu/drm/xe/xe_pcode_api.h b/drivers/gpu/drm/xe/xe_pcode_api.h
> index 2bae9afdbd35..e622ae17f08d 100644
> --- a/drivers/gpu/drm/xe/xe_pcode_api.h
> +++ b/drivers/gpu/drm/xe/xe_pcode_api.h
> @@ -49,6 +49,9 @@
> /* Domain IDs (param2) */
> #define PCODE_MBOX_DOMAIN_HBM 0x2
>
> +#define FAN_SPEED_CONTROL 0x7D
> +#define FSC_READ_NUM_FANS 0x4
> +
> #define PCODE_SCRATCH(x) XE_REG(0x138320 + ((x) * 4))
> /* PCODE_SCRATCH0 */
> #define AUXINFO_REG_OFFSET REG_GENMASK(17, 15)
> --
> 2.34.1
>
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