[PATCH v1] drm/xe/hwmon: expose fan speed
Raag Jadav
raag.jadav at intel.com
Thu Mar 6 18:08:38 UTC 2025
On Thu, Mar 06, 2025 at 08:21:45PM +0530, Poosa, Karthik wrote:
> On 24-02-2025 13:16, Raag Jadav wrote:
> > On Fri, Feb 21, 2025 at 08:32:01PM +0530, Poosa, Karthik wrote:
> > > On 10-02-2025 15:35, 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.
> > > >
> > > > Signed-off-by: Raag Jadav <raag.jadav at intel.com>
> > > > ---
> > > > .../ABI/testing/sysfs-driver-intel-xe-hwmon | 24 ++++
> > > > drivers/gpu/drm/xe/regs/xe_pcode_regs.h | 3 +
> > > > drivers/gpu/drm/xe/xe_hwmon.c | 124 +++++++++++++++++-
> > > > drivers/gpu/drm/xe/xe_pcode_api.h | 3 +
> > > > 4 files changed, 153 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)
> > > Can you rename macros without having platform names, as this register is
> > > available for both DG2 and BMG, like FAN_1_SPEED.
> > Are you sure if we want to break the convention here?
>
> I think we should, as the offset is not for a single platform.
> You can also check if future platforms would continue to use the same
> offset.
My understanding is that the conventions are taken very seriously,
especially in hwmon. But if everyone agrees, I have no objections.
> > > > #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_hwmon.c b/drivers/gpu/drm/xe/xe_hwmon.c
> > > > index 7f327e334212..f1f95655d9fb 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 +165,16 @@ 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 (xe->info.platform == XE_BATTLEMAGE || xe->info.platform == XE_DG2) {
> > > > + 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 +485,7 @@ 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 +512,14 @@ 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_num_fans(const struct xe_hwmon *hwmon, u32 *uval)
> > > > +{
> > > > + struct xe_tile *root_tile = xe_device_get_root_tile(hwmon->xe);
> > > > +
> > > > + return xe_pcode_read(root_tile, PCODE_MBOX(FAN_SPEED_CONTROL,
> > > > + FSC_READ_NUM_FANS, 0), uval, NULL);
> > > > +}
> > > > +
> > > > static int xe_hwmon_power_curr_crit_read(struct xe_hwmon *hwmon, int channel,
> > > > long *value, u32 scale_factor)
> > > > {
> > > > @@ -705,6 +745,77 @@ 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)
> > > > +{
> > > > + struct xe_device *xe = hwmon->xe;
> > > > + u32 uval;
> > > > +
> > > > + switch (attr) {
> > > > + case hwmon_fan_input:
> > > > + if (xe_hwmon_pcode_read_num_fans(hwmon, &uval))
> > > > + return 0;
> > > > +
> > > > + /* Platforms that don't return correct value */
> > > This can be rephrased to - "Platforms that don't support fan pcode mailbox
> > > cmds"
> > We wouldn't be at this point if it was not supported.
>
> Does DG2 return incorrect value ?
>
> AFAIK, FSC_READ_NUM_FANS is not supported on DG2.
The CI results seem to suggest otherwise.
Raag
> > > > + if (xe->info.platform == XE_DG2)
> > > > + uval = 2;
> > > > +
> > > > + return channel < uval ? 0444 : 0;
> > > > + default:
> > > > + return 0;
> > > > + }
> > > > +}
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