Re: [PATCH v2] drm/xe/hwmon: expose package and vram temperature

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Wed, Feb 05, 2025 at 02:02:47PM +0200, Raag Jadav wrote:
> On Wed, Feb 05, 2025 at 12:40:46PM +0530, Riana Tauro wrote:
> > On 2/5/2025 5:15 AM, Rodrigo Vivi wrote:
> > > On Mon, Feb 03, 2025 at 11:57:20AM +0530, Riana Tauro wrote:
> > > > On 2/1/2025 12:07 PM, Raag Jadav wrote:
> > > > > On Fri, Jan 31, 2025 at 08:13:15PM +0530, Poosa, Karthik wrote:
> > > > > > On 31-01-2025 11:15, Raag Jadav wrote:
> > > > > > > Add hwmon support for temp2_input and temp3_input attributes, which will
> > > > > > 
> > > > > > Add hwmon support for temp2_input and temp3_input attributes for supported platforms
> > > > > > 
> > > > > > > expose package and vram temperature in millidegree Celsius. With this in
> > > > > > > place we can monitor temperature using lm-sensors tool.
> > > > > > 
> > > > > > With these changes, package and vram temperatures can be monitored using lm-sensors tool.
> > > > > 
> > > > > That's pretty much what it already says, doesn't it?
> > > > > 
> > > > > > > v2: Reuse existing channels (Badal, Karthik)
> > > > > > Add a new channel for VRAM temperature, channel 3.
> > > > > > > 
> > > > > > > Signed-off-by: Raag Jadav<raag.jadav@intel.com>
> > > > > > > Reviewed-by: Andi Shyti<andi.shyti@linux.intel.com>
> > > > > > > ---
> > > > > > >     .../ABI/testing/sysfs-driver-intel-xe-hwmon   | 16 +++++
> > > > > > >     drivers/gpu/drm/xe/regs/xe_mchbar_regs.h      |  3 +
> > > > > > >     drivers/gpu/drm/xe/regs/xe_pcode_regs.h       |  2 +
> > > > > > >     drivers/gpu/drm/xe/xe_hwmon.c                 | 60 +++++++++++++++++++
> > > > > > >     4 files changed, 81 insertions(+)
> > > > > > > 
> > > > > > > diff --git a/Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon b/Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon
> > > > > > > index d792a56f59ac..9bce281314df 100644
> > > > > > > --- a/Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon
> > > > > > > +++ b/Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon
> > > > > > > @@ -108,3 +108,19 @@ Contact:	intel-xe@lists.freedesktop.org
> > > > > > >     Description:	RO. Package current voltage in millivolt.
> > > > > > >     		Only supported for particular Intel Xe graphics platforms.
> > > > > > > +
> > > > > > > +What:		/sys/bus/pci/drivers/xe/.../hwmon/hwmon<i>/temp2_input
> > > > > > > +Date:		March 2025
> > > > > > 
> > > > > > January 2025,
> > > > > > 
> > > > > > February 2025, if there is a next revision after v2
> > > > > > 
> > > > > > > +KernelVersion:	6.14
> > > > > > > +Contact:	intel-xe@lists.freedesktop.org
> > > > > > > +Description:	RO. Package temperature in millidegree Celsius.
> > > > > > > +
> > > > > > > +		Only supported for particular Intel Xe graphics platforms.
> > > > > > > +
> > > > > > > +What:		/sys/bus/pci/drivers/xe/.../hwmon/hwmon<i>/temp3_input
> > > > > > > +Date:		March 2025
> > > > > > 
> > > > > > January 2025
> > > > > > 
> > > > > > February 2025, if there is a next revision after v2
> > > > > 
> > > > > Something to follow: https://hansen.beer/~dave/phb/
> > > > > 
> > > > > > > +KernelVersion:	6.14
> > > > > > > +Contact:	intel-xe@lists.freedesktop.org
> > > > > > > +Description:	RO. VRAM temperature in millidegree Celsius.
> > > > > > > +
> > > > > > > +		Only supported for particular Intel Xe graphics platforms.
> > > > > > > diff --git a/drivers/gpu/drm/xe/regs/xe_mchbar_regs.h b/drivers/gpu/drm/xe/regs/xe_mchbar_regs.h
> > > > > > > index 519dd1067a19..f5e5234857c1 100644
> > > > > > > --- a/drivers/gpu/drm/xe/regs/xe_mchbar_regs.h
> > > > > > > +++ b/drivers/gpu/drm/xe/regs/xe_mchbar_regs.h
> > > > > > > @@ -34,6 +34,9 @@
> > > > > > >     #define PCU_CR_PACKAGE_ENERGY_STATUS		XE_REG(MCHBAR_MIRROR_BASE_SNB + 0x593c)
> > > > > > > +#define PCU_CR_PACKAGE_TEMPERATURE		XE_REG(MCHBAR_MIRROR_BASE_SNB + 0x5978)
> > > > > > > +#define   TEMP_MASK				REG_GENMASK(7, 0)
> > > > > > TEMP_MASK -> TEMPERATURE_MASK
> > > > > 
> > > > > This is consistent with other GENMASK() macros here.
> > > > > 
> > > > > > >     #define PCU_CR_PACKAGE_RAPL_LIMIT		XE_REG(MCHBAR_MIRROR_BASE_SNB + 0x59a0)
> > > > > > >     #define   PKG_PWR_LIM_1				REG_GENMASK(14, 0)
> > > > > > >     #define   PKG_PWR_LIM_1_EN			REG_BIT(15)
> > > > > > > diff --git a/drivers/gpu/drm/xe/regs/xe_pcode_regs.h b/drivers/gpu/drm/xe/regs/xe_pcode_regs.h
> > > > > > > index 0b0b49d850ae..8846eb9ce2a4 100644
> > > > > > > --- a/drivers/gpu/drm/xe/regs/xe_pcode_regs.h
> > > > > > > +++ b/drivers/gpu/drm/xe/regs/xe_pcode_regs.h
> > > > > > > @@ -21,6 +21,8 @@
> > > > > > >     #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_VRAM_TEMPERATURE			XE_REG(0x1382c0)
> > > > > > > +#define BMG_PACKAGE_TEMPERATURE			XE_REG(0x138434)
> > > > > > >     #define BMG_PACKAGE_RAPL_LIMIT			XE_REG(0x138440)
> > > > > > >     #define BMG_PLATFORM_ENERGY_STATUS		XE_REG(0x138458)
> > > > > > >     #define BMG_PLATFORM_POWER_LIMIT		XE_REG(0x138460)
> > > > > > > diff --git a/drivers/gpu/drm/xe/xe_hwmon.c b/drivers/gpu/drm/xe/xe_hwmon.c
> > > > > > > index fde56dad3ab7..7f327e334212 100644
> > > > > > > --- a/drivers/gpu/drm/xe/xe_hwmon.c
> > > > > > > +++ b/drivers/gpu/drm/xe/xe_hwmon.c
> > > > > > > @@ -6,6 +6,7 @@
> > > > > > >     #include <linux/hwmon-sysfs.h>
> > > > > > >     #include <linux/hwmon.h>
> > > > > > >     #include <linux/types.h>
> > > > > > > +#include <linux/units.h>
> > > > > > >     #include <drm/drm_managed.h>
> > > > > > >     #include "regs/xe_gt_regs.h"
> > > > > > > @@ -20,6 +21,7 @@
> > > > > > >     #include "xe_pm.h"
> > > > > > >     enum xe_hwmon_reg {
> > > > > > > +	REG_TEMP,
> > > > > > 
> > > > > > Any specific reason for adding this at the beginning of enum ?
> > > > > 
> > > > > This follows the ordering of enum hwmon_sensor_types (as the rest of the patch).
> > > > > 
> > > > > > Generally addition is at the end for any new enums.
> > > > > > 
> > > > > > >     	REG_PKG_RAPL_LIMIT,
> > > > > > >     	REG_PKG_POWER_SKU,
> > > > > > >     	REG_PKG_POWER_SKU_UNIT,
> > > > > > > @@ -36,6 +38,7 @@ enum xe_hwmon_reg_operation {
> > > > > > >     enum xe_hwmon_channel {
> > > > > > >     	CHANNEL_CARD,
> > > > > > >     	CHANNEL_PKG,
> > > > > > > +	CHANNEL_VRAM,
> > > > > > >     	CHANNEL_MAX,
> > > > > > >     };
> > > > > > > @@ -84,6 +87,19 @@ static struct xe_reg xe_hwmon_get_reg(struct xe_hwmon *hwmon, enum xe_hwmon_reg
> > > > > > >     	struct xe_device *xe = hwmon->xe;
> > > > > > >     	switch (hwmon_reg) {
> > > > > > > +	case REG_TEMP:
> > > > > > > +		if (xe->info.platform == XE_BATTLEMAGE) {
> > > > > > > +			if (channel == CHANNEL_PKG)
> > > > > > > +				return BMG_PACKAGE_TEMPERATURE;
> > > > > > > +			else if (channel == CHANNEL_VRAM)
> > > > > > > +				return BMG_VRAM_TEMPERATURE;
> > > > > > > +		} else if (xe->info.platform == XE_DG2) {
> > > > > > > +			if (channel == CHANNEL_PKG)
> > > > > > > +				return PCU_CR_PACKAGE_TEMPERATURE;
> > > > > > > +			else if (channel == CHANNEL_VRAM)
> > > > > > > +				return BMG_VRAM_TEMPERATURE;
> > > > > > 
> > > > > > This doesn't look good.
> > > > > > 
> > > > > > Can you add PCU_CR_VRAM_TEMPERATURE with same offset in
> > > > > > xe/regs/xe_mchbar_regs.h ?
> > > > > 
> > > > > It's not mchbar register.
> > > > 
> > > > add it under the same file without the bmg prefix.
> > > > 
> > > > The other registers are platform specific and have the prefix.
> > > > This is common and can have the PCU prefix
> > > 
> > > No, but the point of the xe_mchbar_reg itself is to only
> > > include registers that are from the mchbar.
> > 
> > Sorry for the misunderstanding.
> > I meant under the existing pcode_regs file.
> > 
> > It should be okay to have a common prefix (like PCU) if register is common.
> 
> Although others are platform specific they are expected to be reused in
> the future, aren't they?

This strategy of adding registers with the first platform acronym as register
prefix, then reusing later on the following platforms, was a strategy very
utilized in i915. However, when Lucas refactored the registers accesses here
in Xe, it started a trend of avoiding it, unless needed.

+ Lucas and Thomas


> 
> Do we really want another group in the same range?

perhaps we need to adjust the current ones bringing to the new trend?

> 
> Raag