[RFC PATCH 0/2] mm,drm/ttm: Always block GUP to TTM pages

get_user_pages() to TTM pages is uwanted since TTM assumes it owns the pages exclusively and / or sets up page-table mappings to io memory.

The first patch make sures we stop fast gup to huge TTM pages using a trick with pmd_devmap() and pud_devmap() without a backing dev_pagemap.

The second patch makes sure we block normal gup by setting VM_PFNMAP

Cc: Christian Koenig christian.koenig@amd.com Cc: David Airlie airlied@linux.ie Cc: Daniel Vetter daniel@ffwll.ch Cc: Andrew Morton akpm@linux-foundation.org Cc: Jason Gunthorpe jgg@nvidia.com Cc: linux-mm@kvack.org Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Thomas Hellström (Intel) thomas_os@shipmail.org