{
struct intel_miptree_map *map;
+ /* Estimate the size of the mappable aperture into the GTT. There's an
+ * ioctl to get the whole GTT size, but not one to get the mappable subset.
+ * It turns out it's basically always 256MB, though some ancient hardware
+ * was smaller.
+ */
+ uint32_t gtt_size = 256 * 1024 * 1024;
+ if (intel->gen == 2)
+ gtt_size = 128 * 1024 * 1024;
+
+ /* We don't want to map two objects such that a memcpy between them would
+ * just fault one mapping in and then the other over and over forever. So
+ * we would need to divide the GTT size by 2. Additionally, some GTT is
+ * taken up by things like the framebuffer and the ringbuffer and such, so
+ * be more conservative.
+ */
+ uint32_t max_gtt_map_object_size = gtt_size / 4;
+
assert(mt->num_samples <= 1);
map = intel_miptree_attach_map(mt, level, slice, x, y, w, h, mode);
mt->region->tiling == I915_TILING_X &&
mt->region->pitch < 32768) {
intel_miptree_map_blit(intel, mt, map, level, slice);
+ } else if (mt->region->tiling != I915_TILING_NONE &&
+ mt->region->bo->size >= max_gtt_map_object_size) {
+ assert(mt->region->pitch < 32768);
+ intel_miptree_map_blit(intel, mt, map, level, slice);
} else {
intel_miptree_map_gtt(intel, mt, map, level, slice);
}