[Intel-gfx] [PATCH v4 2/3] drm/i915/vlv: WA for Turbo and RC6 to work together.

Ville Syrjälä ville.syrjala at linux.intel.com
Mon Mar 24 20:26:37 CET 2014


On Sat, Mar 15, 2014 at 08:23:23PM +0530, deepak.s at linux.intel.com wrote:
> From: Deepak S <deepak.s at linux.intel.com>
> 
> With RC6 enabled, BYT has an HW issue in determining the right
> Gfx busyness.
> WA for Turbo + RC6: Use SW based Gfx busy-ness detection to decide
> on increasing/decreasing the freq. This logic will monitor C0
> counters of render/media power-wells over EI period and takes
> necessary action based on these values
> 
> v2: Refactor duplicate code. (Ville)
> 
> v3: Reformat the comments. (Ville)
> 
> v4: Enable required counters and remove unwanted code (Ville)
> 
> Signed-off-by: Deepak S <deepak.s at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.h |  15 +++++
>  drivers/gpu/drm/i915/i915_irq.c | 126 +++++++++++++++++++++++++++++++++++++++-
>  drivers/gpu/drm/i915/i915_reg.h |  13 ++++-
>  drivers/gpu/drm/i915/intel_pm.c |  15 +++--
>  4 files changed, 163 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index d522313..f23c258 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -974,6 +974,12 @@ struct i915_suspend_saved_registers {
>  	u32 savePCH_PORT_HOTPLUG;
>  };
>  
> +struct intel_rps_ei_calc {
> +	u32 cz_ts_ei;
> +	u32 render_ei_c0;
> +	u32 media_ei_c0;
> +};
> +
>  struct intel_gen6_power_mgmt {
>  	/* work and pm_iir are protected by dev_priv->irq_lock */
>  	struct work_struct work;
> @@ -990,6 +996,8 @@ struct intel_gen6_power_mgmt {
>  	bool rp_up_masked;
>  	bool rp_down_masked;
>  
> +	u32 ei_interrupt_count;
> +
>  	int last_adj;
>  	enum { LOW_POWER, BETWEEN, HIGH_POWER } power;
>  
> @@ -1583,6 +1591,13 @@ typedef struct drm_i915_private {
>  	/* gen6+ rps state */
>  	struct intel_gen6_power_mgmt rps;
>  
> +	/* rps wa up ei calculation */
> +	struct intel_rps_ei_calc rps_up_ei;
> +
> +	/* rps wa down ei calculation */
> +	struct intel_rps_ei_calc rps_down_ei;
> +
> +
>  	/* ilk-only ips/rps state. Everything in here is protected by the global
>  	 * mchdev_lock in intel_pm.c */
>  	struct intel_ilk_power_mgmt ips;
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 00b3bfc..a817c43 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -1121,6 +1121,123 @@ void gen6_set_pm_mask(struct drm_i915_private *dev_priv,
>  	}
>  }
>  
> +static u32 vlv_c0_residency(struct drm_i915_private *dev_priv,
> +				struct  intel_rps_ei_calc *rps_ei)
> +{
> +	u32 cz_ts, cz_freq_khz;
> +	u32 render_count, media_count;
> +	u32 elapsed_render, elapsed_media, elapsed_time;
> +	u32 residency = 0;
> +
> +	cz_ts = vlv_punit_read(dev_priv, PUNIT_REG_CZ_TIMESTAMP);
> +	cz_freq_khz = DIV_ROUND_CLOSEST(dev_priv->mem_freq * 1000, 4);
> +
> +	render_count = I915_READ(VLV_RENDER_C0_COUNT_REG);
> +	media_count = I915_READ(VLV_MEDIA_C0_COUNT_REG);
> +
> +	if (rps_ei->cz_ts_ei == 0) {
> +		rps_ei->cz_ts_ei = cz_ts;
> +		rps_ei->render_ei_c0 = render_count;
> +		rps_ei->media_ei_c0 = media_count;
> +
> +		return dev_priv->rps.cur_delay;
> +	}
> +
> +	elapsed_time = cz_ts - rps_ei->cz_ts_ei;
> +	rps_ei->cz_ts_ei = cz_ts;
> +
> +	elapsed_render = render_count - rps_ei->render_ei_c0;
> +	rps_ei->render_ei_c0 = render_count;
> +
> +	elapsed_media = media_count - rps_ei->media_ei_c0;
> +	rps_ei->media_ei_c0 = media_count;
> +
> +	/* Convert all the counters into common unit of milli sec */
> +	elapsed_time /= VLV_CZ_CLOCK_TO_MILLI_SEC;
> +	elapsed_render /=  cz_freq_khz;
> +	elapsed_media /= cz_freq_khz;
> +
> +	/**

This isn't a kernel-doc comment so the double ** shouldn't be here.

> +	 * Calculate overall C0 residency percentage
> +	 * only if elapsed time is non zero
> +	 */
> +	if (elapsed_time) {
> +		residency =
> +			((max(elapsed_render, elapsed_media) * 100)
> +				/ elapsed_time);
> +	}
> +
> +	return residency;
> +}
> +
> +
> +/**
> + * vlv_calc_delay_from_C0_counters - Increase/Decrease freq based on GPU
> + * busy-ness calculated from C0 counters of render & media power wells
> + * @dev_priv: DRM device private
> + *
> + */
> +static u32 vlv_calc_delay_from_C0_counters(struct drm_i915_private *dev_priv)
> +{
> +	u32 residency_C0_up = 0, residency_C0_down = 0;
> +	u8 new_delay;
> +
> +	dev_priv->rps.ei_interrupt_count++;
> +
> +	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
> +
> +
> +	if (dev_priv->rps_up_ei.cz_ts_ei == 0) {
> +		vlv_c0_residency(dev_priv, &dev_priv->rps_up_ei);
> +		vlv_c0_residency(dev_priv, &dev_priv->rps_down_ei);
> +		return dev_priv->rps.cur_delay;
> +	}
> +
> +
> +	/**

here too

> +	 * To down throttle, C0 residency should be less than down threshold
> +	 * for continous EI intervals. So calculate down EI counters
> +	 * once in VLV_INT_COUNT_FOR_DOWN_EI
> +	 */
> +	if (dev_priv->rps.ei_interrupt_count == VLV_INT_COUNT_FOR_DOWN_EI) {
> +
> +		dev_priv->rps.ei_interrupt_count = 0;
> +
> +		residency_C0_down = vlv_c0_residency(dev_priv,
> +						&dev_priv->rps_down_ei);
> +	} else {
> +		residency_C0_up = vlv_c0_residency(dev_priv,
> +						&dev_priv->rps_up_ei);
> +	}
> +
> +	new_delay = dev_priv->rps.cur_delay;
> +
> +	/* C0 residency is greater than UP threshold. Increase Frequency */
> +	if (residency_C0_up >= VLV_RP_UP_EI_THRESHOLD) {
> +
> +		if (dev_priv->rps.cur_delay < dev_priv->rps.max_delay)
> +			new_delay = dev_priv->rps.cur_delay + 1;
> +
> +		/**

and here

> +		 * For better performance, jump directly
> +		 * to RPe if we're below it.
> +		 */
> +		if (new_delay < dev_priv->rps.rpe_delay)
> +			new_delay = dev_priv->rps.rpe_delay;
> +
> +	} else if (!dev_priv->rps.ei_interrupt_count &&
> +			(residency_C0_down < VLV_RP_DOWN_EI_THRESHOLD)) {
> +		/**

ditto

> +		 * This means, C0 residency is less than down threshold over
> +		 * a period of VLV_INT_COUNT_FOR_DOWN_EI. So, reduce the freq
> +		 */
> +		if (dev_priv->rps.cur_delay > dev_priv->rps.min_delay)
> +			new_delay = dev_priv->rps.cur_delay - 1;
> +	}
> +
> +	return new_delay;
> +}
> +
>  static void gen6_pm_rps_work(struct work_struct *work)
>  {
>  	drm_i915_private_t *dev_priv = container_of(work, drm_i915_private_t,
> @@ -1163,6 +1280,8 @@ static void gen6_pm_rps_work(struct work_struct *work)
>  		else
>  			new_delay = dev_priv->rps.min_delay;
>  		adj = 0;
> +	} else if (pm_iir & GEN6_PM_RP_UP_EI_EXPIRED) {
> +		new_delay = vlv_calc_delay_from_C0_counters(dev_priv);
>  	} else if (pm_iir & GEN6_PM_RP_DOWN_THRESHOLD) {
>  		if (adj < 0)
>  			adj *= 2;
> @@ -2989,6 +3108,7 @@ static void gen5_gt_irq_postinstall(struct drm_device *dev)
>  			pm_irqs |= PM_VEBOX_USER_INTERRUPT;
>  
>  		dev_priv->pm_irq_mask = 0xffffffff;
> +
>  		I915_WRITE(GEN6_PMIIR, I915_READ(GEN6_PMIIR));
>  		I915_WRITE(GEN6_PMIMR, dev_priv->pm_irq_mask);
>  		I915_WRITE(GEN6_PMIER, pm_irqs);
> @@ -4031,7 +4151,11 @@ void intel_irq_init(struct drm_device *dev)
>  	INIT_WORK(&dev_priv->l3_parity.error_work, ivybridge_parity_work);
>  
>  	/* Let's track the enabled rps events */
> -	dev_priv->pm_rps_events = GEN6_PM_RPS_EVENTS;
> +	if (IS_VALLEYVIEW(dev))
> +		/* WAUseRC0ResidenncyTurbo:VLV */

I can't see this name in the database (even with the typo fixed).
I do see something called WaGsvRC0ResidencyMethod:vlv which I'm
assuming is the right one.

So apart from the minor nits I listed, my only two remaining issues here
are whether we want to make this optional or not, and whether we should
apply acceleration to the up/down transitions like gen6_pm_rps_work()
does (to ramp the freq up/down faster). I forget if you tested how that
affects the power consumption numbers, or if you just tested the effect
of the __wait_seqno() boost mechanism.

> +		dev_priv->pm_rps_events = GEN6_PM_RP_UP_EI_EXPIRED;
> +	else
> +		dev_priv->pm_rps_events = GEN6_PM_RPS_EVENTS;
>  
>  	setup_timer(&dev_priv->gpu_error.hangcheck_timer,
>  		    i915_hangcheck_elapsed,
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 6174fda..d978b46 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -419,6 +419,7 @@ enum punit_power_well {
>  #define PUNIT_REG_GPU_FREQ_STS			0xd8
>  #define   GENFREQSTATUS				(1<<0)
>  #define PUNIT_REG_MEDIA_TURBO_FREQ_REQ		0xdc
> +#define PUNIT_REG_CZ_TIMESTAMP			0xce
>  
>  #define PUNIT_FUSE_BUS2				0xf6 /* bits 47:40 */
>  #define PUNIT_FUSE_BUS1				0xf5 /* bits 55:48 */
> @@ -434,6 +435,11 @@ enum punit_power_well {
>  #define   FB_FMAX_VMIN_FREQ_LO_SHIFT		27
>  #define   FB_FMAX_VMIN_FREQ_LO_MASK		0xf8000000
>  
> +#define VLV_CZ_CLOCK_TO_MILLI_SEC		100000
> +#define VLV_RP_UP_EI_THRESHOLD			90
> +#define VLV_RP_DOWN_EI_THRESHOLD		70
> +#define VLV_INT_COUNT_FOR_DOWN_EI		5
> +
>  /* vlv2 north clock has */
>  #define CCK_FUSE_REG				0x8
>  #define  CCK_FUSE_HPLL_FREQ_MASK		0x3
> @@ -4892,6 +4898,7 @@ enum punit_power_well {
>  #define  VLV_GTLC_PW_STATUS			0x130094
>  #define VLV_GTLC_PW_RENDER_STATUS_MASK		0x80
>  #define VLV_GTLC_PW_MEDIA_STATUS_MASK		0x20
> +#define VLV_GTLC_SURVIVABILITY_REG              0x130098
>  #define  FORCEWAKE_MT				0xa188 /* multi-threaded */
>  #define   FORCEWAKE_KERNEL			0x1
>  #define   FORCEWAKE_USER			0x2
> @@ -5019,13 +5026,17 @@ enum punit_power_well {
>  
>  #define GEN6_GT_GFX_RC6_LOCKED			0x138104
>  #define VLV_COUNTER_CONTROL			0x138104
> +#define VLV_RC_COUNTER_CONTROL                  0xFFFF00FF
>  #define   VLV_COUNT_RANGE_HIGH			(1<<15)
> +#define   VLV_MEDIA_RC0_COUNT_EN		(1<<5)
> +#define   VLV_RENDER_RC0_COUNT_EN		(1<<4)
>  #define   VLV_MEDIA_RC6_COUNT_EN		(1<<1)
>  #define   VLV_RENDER_RC6_COUNT_EN		(1<<0)
>  #define GEN6_GT_GFX_RC6				0x138108
>  #define GEN6_GT_GFX_RC6p			0x13810C
>  #define GEN6_GT_GFX_RC6pp			0x138110
> -
> +#define VLV_RENDER_C0_COUNT_REG		0x138118
> +#define VLV_MEDIA_C0_COUNT_REG			0x13811C
>  #define GEN6_PCODE_MAILBOX			0x138124
>  #define   GEN6_PCODE_READY			(1<<31)
>  #define   GEN6_READ_OC_PARAMS			0xc
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 95b133a..858cd1f 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -3096,10 +3096,14 @@ static void vlv_set_rps_idle(struct drm_i915_private *dev_priv)
>  		I915_READ(VLV_GTLC_SURVIVABILITY_REG) &
>  				~VLV_GFX_CLK_FORCE_ON_BIT);
>  
> -	/* Unmask Up interrupts */
> -	dev_priv->rps.rp_up_masked = true;
> -	gen6_set_pm_mask(dev_priv, GEN6_PM_RP_DOWN_THRESHOLD,
> +	/* Unmask Turbo interrupts */
> +	if (dev_priv->pm_rps_events & GEN6_PM_RP_UP_EI_EXPIRED)
> +		I915_WRITE(GEN6_PMINTRMSK, ~dev_priv->pm_rps_events);
> +	else {
> +		dev_priv->rps.rp_up_masked = true;
> +		gen6_set_pm_mask(dev_priv, GEN6_PM_RP_DOWN_THRESHOLD,
>  						dev_priv->rps.min_delay);
> +	}
>  }
>  
>  void gen6_rps_idle(struct drm_i915_private *dev_priv)
> @@ -3618,6 +3622,7 @@ static void valleyview_enable_rps(struct drm_device *dev)
>  	I915_WRITE(GEN6_RP_DOWN_EI, 350000);
>  
>  	I915_WRITE(GEN6_RP_IDLE_HYSTERSIS, 10);
> +	I915_WRITE(GEN6_RP_DOWN_TIMEOUT, 0xf4240);
>  
>  	I915_WRITE(GEN6_RP_CONTROL,
>  		   GEN6_RP_MEDIA_TURBO |
> @@ -3638,9 +3643,11 @@ static void valleyview_enable_rps(struct drm_device *dev)
>  
>  	/* allows RC6 residency counter to work */
>  	I915_WRITE(VLV_COUNTER_CONTROL,
> -		   _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH |
> +		   _MASKED_BIT_ENABLE(VLV_MEDIA_RC0_COUNT_EN |
> +				      VLV_RENDER_RC0_COUNT_EN |
>  				      VLV_MEDIA_RC6_COUNT_EN |
>  				      VLV_RENDER_RC6_COUNT_EN));
> +
>  	if (intel_enable_rc6(dev) & INTEL_RC6_ENABLE)
>  		rc6_mode = GEN7_RC_CTL_TO_MODE | VLV_RC_CTL_CTX_RST_PARALLEL;
>  
> -- 
> 1.8.4.2
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Ville Syrjälä
Intel OTC



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