Re: [PATCH] drm/i915: Extend BIOS stolen mem handling to all platform

From: Daniel Vetter <daniel@ffwll.ch>
To: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
Cc: Deepak S <deepak.s@intel.com>,
	Daniel Vetter <daniel.vetter@ffwll.ch>,
	Intel Graphics Development <intel-gfx@lists.freedesktop.org>
Subject: Re: [PATCH] drm/i915: Extend BIOS stolen mem handling to all platform
Date: Fri, 12 Sep 2014 11:39:30 +0200	[thread overview]
Message-ID: <20140912093930.GE4740@phenom.ffwll.local> (raw)
In-Reply-To: <20140912092314.GL4193@intel.com>

On Fri, Sep 12, 2014 at 12:23:14PM +0300, Ville Syrjälä wrote:
> On Thu, Sep 11, 2014 at 01:28:29PM +0200, Daniel Vetter wrote:
> > Based upon a patch from Deepak, but reworked to only apply on gen7+
> > and with the logic a bit clarified.
> > 
> > Cc: Deepak S <deepak.s@intel.com>
> > Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> 
> > ---
> >  drivers/gpu/drm/i915/i915_gem_stolen.c | 13 +++++++++++--
> >  drivers/gpu/drm/i915/i915_reg.h        |  8 ++++++++
> >  2 files changed, 19 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
> > index 21c025a209c0..15d42b3e2029 100644
> > --- a/drivers/gpu/drm/i915/i915_gem_stolen.c
> > +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
> > @@ -289,6 +289,7 @@ void i915_gem_cleanup_stolen(struct drm_device *dev)
> >  int i915_gem_init_stolen(struct drm_device *dev)
> >  {
> >  	struct drm_i915_private *dev_priv = dev->dev_private;
> > +	u32 tmp;
> >  	int bios_reserved = 0;
> >  
> >  #ifdef CONFIG_INTEL_IOMMU
> > @@ -308,8 +309,16 @@ int i915_gem_init_stolen(struct drm_device *dev)
> >  	DRM_DEBUG_KMS("found %zd bytes of stolen memory at %08lx\n",
> >  		      dev_priv->gtt.stolen_size, dev_priv->mm.stolen_base);
> >  
> > -	if (IS_VALLEYVIEW(dev))
> > -		bios_reserved = 1024*1024; /* top 1M on VLV/BYT */
> > +	if (INTEL_INFO(dev)->gen >= 8) {
> > +		tmp = I915_READ(GEN7_BIOS_RESERVED);
> > +		tmp >>= GEN8_BIOS_RESERVED_SHIFT;
> > +		tmp &= GEN8_BIOS_RESERVED_SHIFT;
>                                           ^^^^^
> MASK

Oops, thanks for spotting this.
> 
> The docs are a bit confusing on this topic, but othwewise this seems
> to be OK wrt. most of the docs.
> 
> So with that one thing fixed:
> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

Queued for -next, thanks for the review.
-Daniel
> 
> 
> > +		bios_reserved = (1024*1024) << tmp;
> > +	} else if (IS_GEN7(dev)) {
> > +		tmp = I915_READ(GEN7_BIOS_RESERVED);
> > +		bios_reserved = tmp & GEN7_BIOS_RESERVED_256K ?
> > +			256*1024 : 1024*1024;
> > +	}
> >  
> >  	if (WARN_ON(bios_reserved > dev_priv->gtt.stolen_size))
> >  		return 0;
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > index 15c0eaa9f97f..eb1430974a9a 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -143,6 +143,14 @@
> >  #define GAB_CTL				0x24000
> >  #define   GAB_CTL_CONT_AFTER_PAGEFAULT	(1<<8)
> >  
> > +#define GEN7_BIOS_RESERVED		0x1082C0
> > +#define GEN7_BIOS_RESERVED_1M		(0 << 5)
> > +#define GEN7_BIOS_RESERVED_256K		(1 << 5)
> > +#define GEN8_BIOS_RESERVED_SHIFT       7
> > +#define GEN7_BIOS_RESERVED_MASK        0x1
> > +#define GEN8_BIOS_RESERVED_MASK        0x3
> > +
> > +
> >  /* VGA stuff */
> >  
> >  #define VGA_ST01_MDA 0x3ba
> > -- 
> > 2.0.1
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Ville Syrjälä
> Intel OTC

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch