- Build fix with DMA_CMA enabled
- Introduction of PTE_WRITE to distinguish between writable but clean
and truly read-only pages
- FIQs enabling/disabling clean-up (they aren't used on arm64)
- CPU resume fix for the per-cpu offset restoring
- Code comment typos
arm64: mm: Introduce PTE_WRITE
We have the following means for encoding writable or dirty ptes:
PTE_DIRTY PTE_RDONLY
!pte_dirty && !pte_write 0 1
!pte_dirty && pte_write 0 1
pte_dirty && !pte_write 1 1
pte_dirty && pte_write 1 0
So we can't distinguish between writable clean ptes and read only
ptes. This can cause problems with ptes being incorrectly flagged as
read only when they are writable but not dirty.
This patch introduces a new software bit PTE_WRITE which allows us to
correctly identify writable ptes. PTE_RDONLY is now only clear for
valid ptes where a page is both writable and dirty.
Signed-off-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
1 file changed
