[Intel-gfx] [PATCH] drm/i915/lmem: add the fake lmem region

[Chris Wilson]

Quoting Arkadiusz Hiler (2019-10-31 12:40:35)
> On Wed, Oct 30, 2019 at 10:22:37PM +0000, Matthew Auld wrote:
> > On Tue, 29 Oct 2019 at 16:51, Matthew Auld <matthew.auld at intel.com> wrote:
> > >
> > > Intended for upstream testing so that we can still exercise the LMEM
> > > plumbing and !i915_ggtt_has_aperture paths. Smoke tested on Skull Canyon
> > > device. This works by allocating an intel_memory_region for a reserved
> > > portion of system memory, which we treat like LMEM. For the LMEMBAR we
> > > steal the aperture and 1:1 it map to the stolen region.
> > >
> > > To enable simply set the i915 modparam fake_lmem_start= on the kernel
> > > cmdline with the start of reserved region(see memmap=). The size of the
> > > region we can use is determined by the size of the mappable aperture, so
> > > the size of reserved region should be >= mappable_end. For now we only
> > > enable for the selftests. Depends on CONFIG_DRM_I915_UNSTABLE being
> > > enabled.
> > >
> > > eg. memmap=2G$16G i915.fake_lmem_start=0x400000000
> > 
> > Hi Arek,
> > 
> > Would you be able to update the fi-skl-lmem kernel cmd line with
> > s/i915_fake_lmem_start/i915.fake_lmem_start?
> 
> done

<6>[  497.897456] [drm] Intel graphics fake LMEM: [mem 0x100000000-0x13fffffff]
<6>[  497.897459] [drm] Intel graphics fake LMEM IO start: 40000000
<6>[  497.897461] [drm] Intel graphics fake LMEM size: 40000000

All present.
-Chris