On g33, the documentation states
HWS_PGA:
Format = Bits 28:12 of graphics memory address (bits 31:29 MBZ).
which translates to that the address of the HWS must be below 256MiB,
which is conveniently the mappable aperture.
This also appears to be true (but not documented as so) for gen4 and
This also appears to be true (but not documented as so) for gen4 and
gen5. To generalise we force it into the low mappable region for all
non-LLC platforms. If we locate the HWS at the top of the GTT the
machine will hard hang during boot (fails on pnv, gm45, ilk and byt,
but works on snb, ivb,
On Mon, May 19, 2014 at 07:56:11AM +0100, Chris Wilson wrote:
This also appears to be true (but not documented as so) for gen4 and
gen5. To generalise we force it into the low mappable region for all
non-LLC platforms. If we locate the HWS at the top of the GTT the
machine will hard hang
