Re: [Intel-gfx] [PATCH v2] drm/i915/gt: Add sysfs RAPL PL1 interface

["Dixit, Ashutosh" <ashutosh.dixit@intel.com>]

On Mon, 30 Jan 2023 22:25:50 -0800, Sujaritha Sundaresan wrote:
>

Hi Suja,

> Adding sysfs attribute rapl_pl1_freq_mhz. This shows the RAPL PL1
> FREQUENCY LIMIT.

For MTL do we know if this RAPL PL1 freq limit is for just the GPU or the
SOC (CPU + GPU)?

>
> Signed-off-by: Sujaritha Sundaresan <sujaritha.sundaresan@intel.com>
> ---
>  drivers/gpu/drm/i915/gt/intel_gt_regs.h     |  4 ++++
>  drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c | 15 +++++++++++++++
>  drivers/gpu/drm/i915/gt/intel_rps.c         | 18 ++++++++++++++++++
>  drivers/gpu/drm/i915/gt/intel_rps.h         |  1 +
>  4 files changed, 38 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> index 7fa18a3b3957..1c78fc89a37a 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> @@ -1656,6 +1656,10 @@
>  #define GT0_PACKAGE_POWER_SKU_UNIT		_MMIO(0x250068)
>  #define GT0_PLATFORM_ENERGY_STATUS		_MMIO(0x25006c)
>
> +#define XEHPSDV_RAPL_PL1_FREQ_LIMIT		_MMIO(0x250070)
> +#define MTL_RAPL_PL1_FREQ_LIMIT		_MMIO(0x281070)
> +#define   RAPL_PL1_FREQ_LIMIT_MASK		REG_GENMASK(15, 0)
> +
>  /*
>   * Standalone Media's non-engine GT registers are located at their regular GT
>   * offsets plus 0x380000.  This extra offset is stored inside the intel_uncore
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c b/drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c
> index 28f27091cd3b..0b52962e2856 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c
> @@ -451,6 +451,16 @@ static ssize_t punit_req_freq_mhz_show(struct kobject *kobj,
>	return sysfs_emit(buff, "%u\n", preq);
>  }
>
> +static ssize_t rapl_pl1_freq_mhz_show(struct kobject *kobj,
> +				      struct kobj_attribute *attr,
> +				      char *buff)
> +{
> +	struct intel_gt *gt = intel_gt_sysfs_get_drvdata(kobj, attr->attr.name);
> +	u32 rapl_pl1 = intel_rps_read_rapl_pl1(&gt->rps);
> +
> +	return sysfs_emit(buff, "%u\n", rapl_pl1);
> +}
> +
>  struct intel_gt_bool_throttle_attr {
>	struct attribute attr;
>	ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
> @@ -480,6 +490,7 @@ struct intel_gt_bool_throttle_attr attr_##sysfs_func__ = { \
>  }
>
>  INTEL_GT_ATTR_RO(punit_req_freq_mhz);
> +INTEL_GT_ATTR_RO(rapl_pl1_freq_mhz);
>  static INTEL_GT_RPS_BOOL_ATTR_RO(throttle_reason_status, GT0_PERF_LIMIT_REASONS_MASK);
>  static INTEL_GT_RPS_BOOL_ATTR_RO(throttle_reason_pl1, POWER_LIMIT_1_MASK);
>  static INTEL_GT_RPS_BOOL_ATTR_RO(throttle_reason_pl2, POWER_LIMIT_2_MASK);
> @@ -744,6 +755,10 @@ void intel_gt_sysfs_pm_init(struct intel_gt *gt, struct kobject *kobj)
>	if (ret)
>		gt_warn(gt, "failed to create punit_req_freq_mhz sysfs (%pe)", ERR_PTR(ret));
>
> +	ret = sysfs_create_file(kobj, &attr_rapl_pl1_freq_mhz.attr);
> +	if (ret)
> +		gt_warn(gt, "failed to create rapl_pl1_freq_mhz sysfs (%pe)", ERR_PTR(ret));
> +

As I said previously we should create the rapl_pl1_freq_mhz file only on
platforms on which it is is available. So let's put the above code block
inside the if () below:

	if (GRAPHICS_VER_FULL(gt->i915) >= IP_VER(12, 70) || IS_XEHPSDV(gt->i915)) {
		ret = sysfs_create_file(kobj, &attr_rapl_pl1_freq_mhz.attr);
		if (ret)
			gt_warn(gt, "failed to create rapl_pl1_freq_mhz sysfs (%pe)", ERR_PTR(ret));
	}

Where MTL graphics version is 12.70 so I am assuming this will be availble
for all later products too and it will help us to not modify the code for
each individual product (unless we have to).

>	if (i915_mmio_reg_valid(intel_gt_perf_limit_reasons_reg(gt))) {
>		ret = sysfs_create_files(kobj, throttle_reason_attrs);
>		if (ret)
> diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c b/drivers/gpu/drm/i915/gt/intel_rps.c
> index f5d7b5126433..f66d6f47f2cf 100644
> --- a/drivers/gpu/drm/i915/gt/intel_rps.c
> +++ b/drivers/gpu/drm/i915/gt/intel_rps.c
> @@ -2202,6 +2202,24 @@ u32 intel_rps_get_max_frequency(struct intel_rps *rps)
>		return intel_gpu_freq(rps, rps->max_freq_softlimit);
>  }
>
> +u32 intel_rps_read_rapl_pl1(struct intel_rps *rps)
> +{
> +	struct drm_i915_private *i915 = rps_to_i915(rps);
> +	u32 rapl_pl1;
> +	u32 rapl;
> +
> +	if (IS_METEORLAKE(i915))
> +		rapl_pl1 = intel_uncore_read(rps_to_gt(rps)->uncore, MTL_RAPL_PL1_FREQ_LIMIT);
> +	else if (IS_XEHPSDV(i915))
> +		rapl_pl1  = intel_uncore_read(rps_to_gt(rps)->uncore, XEHPSDV_RAPL_PL1_FREQ_LIMIT);
> +
> +
> +	if (IS_METEORLAKE(i915) || IS_XEHPSDV(i915))
> +		rapl = REG_FIELD_GET(RAPL_PL1_FREQ_LIMIT_MASK, rapl_pl1);
> +
> +	return rapl;
> +}

This should be something like this:

u32 intel_rps_read_rapl_pl1(struct intel_rps *rps)
{
	struct drm_i915_private *i915 = rps_to_i915(rps);
	i915_reg_t rgadr = INVALID_MMIO_REG;
	u32 rapl_pl1, rapl;

	if (GRAPHICS_VER_FULL(gt->i915) >= IP_VER(12, 70))
		rgadr = MTL_RAPL_PL1_FREQ_LIMIT;
	else if (IS_XEHPSDV(i915))
		rgadr = XEHPSDV_RAPL_PL1_FREQ_LIMIT;

	rapl_pl1 = rps_read_mmio(gt, rgadr);
	rapl = REG_FIELD_GET(RAPL_PL1_FREQ_LIMIT_MASK, rapl_pl1);

	return rapl;
}

rps_read_mmio is needed to take the runtime PM wakeref, we cannot use
intel_uncore_read directly. Note also that we've already ensured that
rapl_pl1_freq_mhz file is only available for XEHPSDV and >= 12.70.

Thanks.
--
Ashutosh

> +
>  /**
>   * intel_rps_get_max_raw_freq - returns the max frequency in some raw format.
>   * @rps: the intel_rps structure
> diff --git a/drivers/gpu/drm/i915/gt/intel_rps.h b/drivers/gpu/drm/i915/gt/intel_rps.h
> index c622962c6bef..c37d297c9d82 100644
> --- a/drivers/gpu/drm/i915/gt/intel_rps.h
> +++ b/drivers/gpu/drm/i915/gt/intel_rps.h
> @@ -51,6 +51,7 @@ u32 intel_rps_get_rp1_frequency(struct intel_rps *rps);
>  u32 intel_rps_get_rpn_frequency(struct intel_rps *rps);
>  u32 intel_rps_read_punit_req(struct intel_rps *rps);
>  u32 intel_rps_read_punit_req_frequency(struct intel_rps *rps);
> +u32 intel_rps_read_rapl_pl1(struct intel_rps *rps);
>  u32 intel_rps_read_rpstat(struct intel_rps *rps);
>  u32 intel_rps_read_rpstat_fw(struct intel_rps *rps);
>  void gen6_rps_get_freq_caps(struct intel_rps *rps, struct intel_rps_freq_caps *caps);
> --
> 2.34.1
>