Re: [Intel-gfx] [PATCH 2/5] drm/i915: Use GEN12_RPSTAT register for GT freq

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

On Wed, Oct 19, 2022 at 04:37:18PM -0700, Ashutosh Dixit wrote:
> From: Don Hiatt <don.hiatt@intel.com>
> 
> On GEN12+ use GEN12_RPSTAT register to get actual resolved GT
> freq. GEN12_RPSTAT does not require a forcewake and will return 0 freq if
> GT is in RC6.
> 
> v2:
>   - Fixed review comments(Ashutosh)
>   - Added function intel_rps_read_rpstat_fw to read RPSTAT without
>     forcewake, required especially for GEN6_RPSTAT1 (Ashutosh, Tvrtko)
> v3:
>   - Updated commit title and message for more clarity (Ashutosh)
>   - Replaced intel_rps_read_rpstat with direct read to GEN12_RPSTAT1 in
>     read_cagf (Ashutosh)
> v4: Remove GEN12_CAGF_SHIFT and use REG_FIELD_GET (Rodrigo)
> 
> Cc: Don Hiatt <donhiatt@gmail.com>
> Cc: Andi Shyti <andi.shyti@intel.com>
> Signed-off-by: Don Hiatt <don.hiatt@intel.com>
> Signed-off-by: Badal Nilawar <badal.nilawar@intel.com>
> Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
> Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
> ---
>  drivers/gpu/drm/i915/gt/intel_gt_regs.h |  1 +
>  drivers/gpu/drm/i915/gt/intel_rps.c     | 32 +++++++++++++++++++++----
>  drivers/gpu/drm/i915/gt/intel_rps.h     |  2 ++
>  drivers/gpu/drm/i915/i915_pmu.c         |  3 +--
>  4 files changed, 32 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> index 35c039573294c..f8c4f758ac0b1 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> @@ -1539,6 +1539,7 @@
>  
>  #define GEN12_RPSTAT1				_MMIO(0x1381b4)
>  #define   GEN12_VOLTAGE_MASK			REG_GENMASK(10, 0)
> +#define   GEN12_CAGF_MASK			REG_GENMASK(19, 11)
>  
>  #define GEN11_GT_INTR_DW(x)			_MMIO(0x190018 + ((x) * 4))
>  #define   GEN11_CSME				(31)
> diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c b/drivers/gpu/drm/i915/gt/intel_rps.c
> index 5bd6671554a6e..da6b969f554b6 100644
> --- a/drivers/gpu/drm/i915/gt/intel_rps.c
> +++ b/drivers/gpu/drm/i915/gt/intel_rps.c
> @@ -2068,12 +2068,34 @@ void intel_rps_sanitize(struct intel_rps *rps)
>  		rps_disable_interrupts(rps);
>  }
>  
> +u32 intel_rps_read_rpstat_fw(struct intel_rps *rps)
> +{
> +	struct drm_i915_private *i915 = rps_to_i915(rps);
> +	i915_reg_t rpstat;
> +
> +	rpstat = (GRAPHICS_VER(i915) >= 12) ? GEN12_RPSTAT1 : GEN6_RPSTAT1;
> +
> +	return intel_uncore_read_fw(rps_to_gt(rps)->uncore, rpstat);
> +}
> +
> +u32 intel_rps_read_rpstat(struct intel_rps *rps)
> +{
> +	struct drm_i915_private *i915 = rps_to_i915(rps);
> +	i915_reg_t rpstat;
> +
> +	rpstat = (GRAPHICS_VER(i915) >= 12) ? GEN12_RPSTAT1 : GEN6_RPSTAT1;
> +
> +	return intel_uncore_read(rps_to_gt(rps)->uncore, rpstat);
> +}
> +
>  u32 intel_rps_get_cagf(struct intel_rps *rps, u32 rpstat)
>  {
>  	struct drm_i915_private *i915 = rps_to_i915(rps);
>  	u32 cagf;
>  
> -	if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915))
> +	if (GRAPHICS_VER(i915) >= 12)
> +		cagf = REG_FIELD_GET(GEN12_CAGF_MASK, rpstat);
> +	else if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915))
>  		cagf = REG_FIELD_GET(RPE_MASK, rpstat);
>  	else if (GRAPHICS_VER(i915) >= 9)
>  		cagf = REG_FIELD_GET(GEN9_CAGF_MASK, rpstat);
> @@ -2093,7 +2115,9 @@ static u32 read_cagf(struct intel_rps *rps)
>  	struct intel_uncore *uncore = rps_to_uncore(rps);
>  	u32 freq;
>  
> -	if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915)) {
> +	if (GRAPHICS_VER(i915) >= 12) {
> +		freq = intel_uncore_read(uncore, GEN12_RPSTAT1);
> +	} else if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915)) {
>  		vlv_punit_get(i915);
>  		freq = vlv_punit_read(i915, PUNIT_REG_GPU_FREQ_STS);
>  		vlv_punit_put(i915);
> @@ -2259,7 +2283,7 @@ static void rps_frequency_dump(struct intel_rps *rps, struct drm_printer *p)
>  	rpinclimit = intel_uncore_read(uncore, GEN6_RP_UP_THRESHOLD);
>  	rpdeclimit = intel_uncore_read(uncore, GEN6_RP_DOWN_THRESHOLD);
>  
> -	rpstat = intel_uncore_read(uncore, GEN6_RPSTAT1);
> +	rpstat = intel_rps_read_rpstat(rps);
>  	rpcurupei = intel_uncore_read(uncore, GEN6_RP_CUR_UP_EI) & GEN6_CURICONT_MASK;
>  	rpcurup = intel_uncore_read(uncore, GEN6_RP_CUR_UP) & GEN6_CURBSYTAVG_MASK;
>  	rpprevup = intel_uncore_read(uncore, GEN6_RP_PREV_UP) & GEN6_CURBSYTAVG_MASK;
> @@ -2394,7 +2418,7 @@ static void slpc_frequency_dump(struct intel_rps *rps, struct drm_printer *p)
>  	drm_printf(p, "PM MASK=0x%08x\n", pm_mask);
>  	drm_printf(p, "pm_intrmsk_mbz: 0x%08x\n",
>  		   rps->pm_intrmsk_mbz);
> -	drm_printf(p, "RPSTAT1: 0x%08x\n", intel_uncore_read(uncore, GEN6_RPSTAT1));
> +	drm_printf(p, "RPSTAT1: 0x%08x\n", intel_rps_read_rpstat(rps));
>  	drm_printf(p, "RPNSWREQ: %dMHz\n", intel_rps_get_requested_frequency(rps));
>  	drm_printf(p, "Lowest (RPN) frequency: %dMHz\n",
>  		   intel_gpu_freq(rps, caps.min_freq));
> diff --git a/drivers/gpu/drm/i915/gt/intel_rps.h b/drivers/gpu/drm/i915/gt/intel_rps.h
> index 110300dfd4383..9e1cad9ba0e9c 100644
> --- a/drivers/gpu/drm/i915/gt/intel_rps.h
> +++ b/drivers/gpu/drm/i915/gt/intel_rps.h
> @@ -48,6 +48,8 @@ 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_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);
>  void intel_rps_raise_unslice(struct intel_rps *rps);
>  void intel_rps_lower_unslice(struct intel_rps *rps);
> diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c
> index 958b37123bf12..67140a87182f8 100644
> --- a/drivers/gpu/drm/i915/i915_pmu.c
> +++ b/drivers/gpu/drm/i915/i915_pmu.c
> @@ -371,7 +371,6 @@ static void
>  frequency_sample(struct intel_gt *gt, unsigned int period_ns)
>  {
>  	struct drm_i915_private *i915 = gt->i915;
> -	struct intel_uncore *uncore = gt->uncore;
>  	struct i915_pmu *pmu = &i915->pmu;
>  	struct intel_rps *rps = &gt->rps;
>  
> @@ -394,7 +393,7 @@ frequency_sample(struct intel_gt *gt, unsigned int period_ns)
>  		 * case we assume the system is running at the intended
>  		 * frequency. Fortunately, the read should rarely fail!
>  		 */
> -		val = intel_uncore_read_fw(uncore, GEN6_RPSTAT1);
> +		val = intel_rps_read_rpstat_fw(rps);
>  		if (val)
>  			val = intel_rps_get_cagf(rps, val);
>  		else
> -- 
> 2.38.0
>