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

Message

Thomas Hellström (Intel) March 21, 2021, 6:45 p.m. UTC

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 <[e-mail]>
Cc: David Airlie <[e-mail]>
Cc: Daniel Vetter <[e-mail]>
Cc: Andrew Morton <[e-mail]>
Cc: Jason Gunthorpe <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Signed-off-by: Thomas Hellström (Intel) <[e-mail]>