TTM_TT_FLAG_BACKED_UP
tt->page_flags |= TTM_TT_FLAG_BACKED_UP;
tt->page_flags &= ~TTM_TT_FLAG_BACKED_UP;
ttm->page_flags &= ~TTM_TT_FLAG_BACKED_UP;
return tt->page_flags & (TTM_TT_FLAG_SWAPPED | TTM_TT_FLAG_BACKED_UP);
return tt->page_flags & TTM_TT_FLAG_BACKED_UP;
tt->page_flags &= ~TTM_TT_FLAG_BACKED_UP;