arm64/mm: Add uffd write-protect support

Let's use the newly-free PTE SW bit (58) to add support for uffd-wp.

The standard handlers are implemented for set/test/clear for both pte
and pmd. Additionally we must also track the uffd-wp state as a pte swp
bit, so use a free swap pte bit (3).

Acked-by: Peter Xu <[email protected]>
Reviewed-by: Catalin Marinas <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Signed-off-by: Ryan Roberts <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>

0 files changed, 0 insertions, 0 deletions