Re: [PATCH 27/71] drm/i915/chv: Enable Render Standby (RC6) for Cheeryview

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Thu, Apr 10, 2014 at 07:51:03PM +0300, Jani Nikula wrote:
> On Wed, 09 Apr 2014, ville.syrjala@linux.intel.com wrote:
> > From: Deepak S <deepak.s@intel.com>
> >
> > v2: Configure PCBR if BIOS fails allocate pcbr (deepak)
> >
> > Signed-off-by: Deepak S <deepak.s@intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_pm.c | 101 ++++++++++++++++++++++++++++++++++++++--
> >  1 file changed, 98 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> > index 0889af7..909cc0a 100644
> > --- a/drivers/gpu/drm/i915/intel_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > @@ -3184,6 +3184,18 @@ static void gen6_disable_rps(struct drm_device *dev)
> >  	gen6_disable_rps_interrupts(dev);
> >  }
> >  
> > +static void cherryview_disable_rps(struct drm_device *dev)
> > +{
> > +	struct drm_i915_private *dev_priv = dev->dev_private;
> > +
> > +	I915_WRITE(GEN6_RC_CONTROL, 0);
> > +
> > +	if (dev_priv->vlv_pctx) {
> > +		drm_gem_object_unreference(&dev_priv->vlv_pctx->base);
> > +		dev_priv->vlv_pctx = NULL;
> > +	}
> > +}
> > +
> >  static void valleyview_disable_rps(struct drm_device *dev)
> >  {
> >  	struct drm_i915_private *dev_priv = dev->dev_private;
> > @@ -3551,6 +3563,29 @@ int valleyview_rps_min_freq(struct drm_i915_private *dev_priv)
> >  	return vlv_punit_read(dev_priv, PUNIT_REG_GPU_LFM) & 0xff;
> >  }
> >  
> > +static void cherryview_setup_pctx(struct drm_device *dev)
> > +{
> > +	struct drm_i915_private *dev_priv = dev->dev_private;
> > +	unsigned long pctx_paddr;
> > +	struct i915_gtt *gtt = &dev_priv->gtt;
> > +	u32 pcbr;
> > +	int pctx_size = 32*1024;
> > +
> > +	pcbr = I915_READ(VLV_PCBR);
> > +	if (pcbr >> 12 == 0) {
> > +		/*
> > +		 * From the Gunit register HAS:
> > +		 * The Gfx driver is expected to program this register and ensure
> > +		 * proper allocation within Gfx stolen memory.  For example, this
> > +		 * register should be programmed such than the PCBR range does not
> > +		 * overlap with other relevant ranges.
> > +		 */
> > +		pctx_paddr = (dev_priv->mm.stolen_base + gtt->stolen_size - pctx_size);
> > +		I915_WRITE(VLV_PCBR, pctx_paddr);
> > +	}
> > +}
> > +
> > +
> >  static void valleyview_setup_pctx(struct drm_device *dev)
> >  {
> >  	struct drm_i915_private *dev_priv = dev->dev_private;
> > @@ -3595,6 +3630,61 @@ out:
> >  	dev_priv->vlv_pctx = pctx;
> >  }
> >  
> > +static void cherryview_enable_rps(struct drm_device *dev)
> > +{
> > +	struct drm_i915_private *dev_priv = dev->dev_private;
> > +	struct intel_ring_buffer *ring;
> > +	u32 gtfifodbg, rc6_mode = 0, pcbr;
> > +	int i;
> > +
> > +	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
> > +
> > +	if ((gtfifodbg = I915_READ(GTFIFODBG))) {
> 
> Please no assignment within if; this one's easy to split.
> 
> There's a bunch of other checkpatch issues in the series; I don't
> personally care about most of them but you might want to run it and see
> if you want to do something about it.

Looks like it's a straight up copy-paste from the gen6 and vlv code. So
someone might want to clean those out as well.

And maybe we should just drop this check for CHV since the GT wake FIFO
isn't used anymore. But I'm not sure if the register still hold something
sensible or not.

> 
> BR,
> Jani.
> 
> 
> > +		DRM_DEBUG_DRIVER("GT fifo had a previous error %x\n",
> > +				 gtfifodbg);
> > +		I915_WRITE(GTFIFODBG, gtfifodbg);
> > +	}
> > +
> > +	cherryview_setup_pctx(dev);
> > +
> > +	/* 1a & 1b: Get forcewake during program sequence. Although the driver
> > +	 * hasn't enabled a state yet where we need forcewake, BIOS may have.*/
> > +	gen6_gt_force_wake_get(dev_priv, FORCEWAKE_ALL);
> > +
> > +	/* 2a: Program RC6 thresholds.*/
> > +	I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 40 << 16);
> > +	I915_WRITE(GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
> > +	I915_WRITE(GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
> > +
> > +	for_each_ring(ring, dev_priv, i)
> > +		I915_WRITE(RING_MAX_IDLE(ring->mmio_base), 10);
> > +
> > +	I915_WRITE(GEN6_RC6_THRESHOLD, 50000); /* 50/125ms per EI */
> > +
> > +	/* allows RC6 residency counter to work */
> > +	I915_WRITE(VLV_COUNTER_CONTROL,
> > +		   _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH |
> > +				      VLV_MEDIA_RC6_COUNT_EN |
> > +				      VLV_RENDER_RC6_COUNT_EN));
> > +
> > +	/* Todo: If BIOS has not configured PCBR
> > +	 *       then allocate in BIOS Reserved */
> > +
> > +	/* For now we assume BIOS is allocating and populating the PCBR  */
> > +	pcbr = I915_READ(VLV_PCBR);
> > +
> > +	DRM_DEBUG_DRIVER("PCBR offset : 0x%x\n", pcbr);
> > +
> > +	/* 3: Enable RC6 */
> > +	if (intel_enable_rc6(dev) & INTEL_RC6_ENABLE & (pcbr >> 12))
> > +		rc6_mode = GEN6_RC_CTL_EI_MODE(1) | VLV_RC_CTL_CTX_RST_PARALLEL;
> > +
> > +	I915_WRITE(GEN6_RC_CONTROL, rc6_mode);
> > +
> > +	gen6_gt_force_wake_put(dev_priv, FORCEWAKE_ALL);
> > +}
> > +
> > +
> >  static void valleyview_enable_rps(struct drm_device *dev)
> >  {
> >  	struct drm_i915_private *dev_priv = dev->dev_private;
> > @@ -4437,7 +4527,9 @@ void intel_disable_gt_powersave(struct drm_device *dev)
> >  		cancel_delayed_work_sync(&dev_priv->rps.delayed_resume_work);
> >  		cancel_work_sync(&dev_priv->rps.work);
> >  		mutex_lock(&dev_priv->rps.hw_lock);
> > -		if (IS_VALLEYVIEW(dev))
> > +		if (IS_CHERRYVIEW(dev))
> > +			cherryview_disable_rps(dev);
> > +		else if (IS_VALLEYVIEW(dev))
> >  			valleyview_disable_rps(dev);
> >  		else
> >  			gen6_disable_rps(dev);
> > @@ -4455,7 +4547,9 @@ static void intel_gen6_powersave_work(struct work_struct *work)
> >  
> >  	mutex_lock(&dev_priv->rps.hw_lock);
> >  
> > -	if (IS_VALLEYVIEW(dev)) {
> > +	if (IS_CHERRYVIEW(dev)) {
> > +		cherryview_enable_rps(dev);
> > +	} else if (IS_VALLEYVIEW(dev)) {
> >  		valleyview_enable_rps(dev);
> >  	} else if (IS_BROADWELL(dev)) {
> >  		gen8_enable_rps(dev);
> > @@ -4476,7 +4570,7 @@ void intel_enable_gt_powersave(struct drm_device *dev)
> >  		ironlake_enable_drps(dev);
> >  		ironlake_enable_rc6(dev);
> >  		intel_init_emon(dev);
> > -	} else if (IS_GEN6(dev) || IS_GEN7(dev)) {
> > +	} else if (INTEL_INFO(dev)->gen >= 6) {
> >  		if (IS_VALLEYVIEW(dev))
> >  			valleyview_setup_pctx(dev);
> >  		/*
> > @@ -5051,6 +5145,7 @@ static void valleyview_init_clock_gating(struct drm_device *dev)
> >  		dev_priv->mem_freq = 1333;
> >  		break;
> >  	}
> > +
> >  	DRM_DEBUG_DRIVER("DDR speed: %d MHz", dev_priv->mem_freq);
> >  
> >  	dev_priv->vlv_cdclk_freq = valleyview_cur_cdclk(dev_priv);
> > -- 
> > 1.8.3.2
> >
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Jani Nikula, Intel Open Source Technology Center

-- 
Ville Syrjälä
Intel OTC