intel: limit aperture space to mappable area on gen3

Otherwise we blow up on heavy tiled blitter loads (with giant
pixmaps).

Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>

diff --git a/intel/intel_bufmgr_gem.c b/intel/intel_bufmgr_gem.c
index dd58c0c..0cfeb98 100644 (file)
--- a/intel/intel_bufmgr_gem.c
+++ b/intel/intel_bufmgr_gem.c
@@ -2204,6 +2204,14 @@ drm_intel_bufmgr_gem_init(int fd, int batch_size)
        else
                bufmgr_gem->gen = 6;
 
+       if (IS_GEN3(bufmgr_gem) && bufmgr_gem->gtt_size > 256*1024*1024) {
+               /* The unmappable part of gtt on gen 3 (i.e. above 256MB) can't
+                * be used for tiled blits. To simplify the accounting, just
+                * substract the unmappable part (fixed to 256MB on all known
+                * gen3 devices) if the kernel advertises it. */
+               bufmgr_gem->gtt_size -= 256*1024*1024;
+       }
+
        gp.value = &tmp;
 
        gp.param = I915_PARAM_HAS_EXECBUF2;