[Intel-gfx] [PATCH] drm/i915/skl: Update eDRAM calculation

[Ben Widawsky]

On Thu, Apr 14, 2016 at 11:14:48AM +0300, Jani Nikula wrote:
> On Thu, 14 Apr 2016, Jani Nikula <jani.nikula at linux.intel.com> wrote:
> > On Wed, 13 Apr 2016, Ben Widawsky <ben at bwidawsk.net> wrote:
> >> The two behavioral changes here are the correct detection of the eDRAM size on
> >> gen9 (SKL + KBL), and unconditional printing of the eLLC size.
> >>
> >> Cc: Eero Tamminen <eero.t.tamminen at intel.com>
> >> Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
> >
> > Please see [1].
> >
> > BR,
> > Jani.
> >
> >
> > [1] http://patchwork.freedesktop.org/patch/msgid/1460557604-7126-3-git-send-email-mika.kuoppala@intel.com
> 
> I did mean to refer to the entire series
> 
> https://patchwork.freedesktop.org/series/5663/
> 
> 

My patch is more correct as it does the proper calculation.

> >
> >
> >> ---
> >>  drivers/gpu/drm/i915/intel_uncore.c | 16 +++++++++++++---
> >>  1 file changed, 13 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
> >> index fbc1d21..efef724 100644
> >> --- a/drivers/gpu/drm/i915/intel_uncore.c
> >> +++ b/drivers/gpu/drm/i915/intel_uncore.c
> >> @@ -314,8 +314,17 @@ static void intel_uncore_ellc_detect(struct drm_device *dev)
> >>  {
> >>  	struct drm_i915_private *dev_priv = dev->dev_private;
> >>  
> >> -	if ((IS_HASWELL(dev) || IS_BROADWELL(dev) ||
> >> -	     INTEL_INFO(dev)->gen >= 9) &&
> >> +	if (INTEL_INFO(dev)->gen >= 9 && HAS_LLC(dev)) {
> >> +		u32 edramcap = __raw_i915_read32(dev_priv, HSW_EDRAM_PRESENT);
> >> +		if (edramcap & EDRAM_ENABLED) {
> >> +			int sets = (edramcap >> 8) & 0x3;
> >> +			int ways = (edramcap >> 5) & 0x7;
> >> +			int banks = (edramcap >> 1) & 0xf;
> >> +
> >> +			ways = (ways + 1) * 4;
> >> +			dev_priv->ellc_size = sets * ways * banks;
> >> +		}
> >> +	} else if ((IS_HASWELL(dev) || IS_BROADWELL(dev)) &&
> >>  	    (__raw_i915_read32(dev_priv, HSW_EDRAM_PRESENT) & EDRAM_ENABLED)) {
> >>  		/* The docs do not explain exactly how the calculation can be
> >>  		 * made. It is somewhat guessable, but for now, it's always
> >> @@ -323,8 +332,9 @@ static void intel_uncore_ellc_detect(struct drm_device *dev)
> >>  		 * NB: We can't write IDICR yet because we do not have gt funcs
> >>  		 * set up */
> >>  		dev_priv->ellc_size = 128;
> >> -		DRM_INFO("Found %zuMB of eLLC\n", dev_priv->ellc_size);
> >>  	}
> >> +
> >> +	DRM_INFO("Found %zuMB of eLLC\n", dev_priv->ellc_size);
> >>  }
> >>  
> >>  static bool
> 
> -- 
> Jani Nikula, Intel Open Source Technology Center