diff options
| author | Will Deacon <will.deacon@arm.com> | 2018-01-29 11:59:54 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-02-16 20:22:50 +0100 |
| commit | ee28fed5ccc66fbdef4119451aa6754501705a7e (patch) | |
| tree | 19a25fb0c68ee712bf4245878c33effbebc3b2e6 /arch/arm64/mm | |
| parent | 69288201803aecffd7f17ffa9c0c5043ffb8367c (diff) | |
arm64: mm: Permit transitioning from Global to Non-Global without BBM
Commit 4e6020565596 upstream.
Break-before-make is not needed when transitioning from Global to
Non-Global mappings, provided that the contiguous hint is not being used.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm64/mm')
| -rw-r--r-- | arch/arm64/mm/mmu.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 606c3654186f..fa20124c19d5 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -117,6 +117,10 @@ static bool pgattr_change_is_safe(u64 old, u64 new) if ((old | new) & PTE_CONT) return false; + /* Transitioning from Global to Non-Global is safe */ + if (((old ^ new) == PTE_NG) && (new & PTE_NG)) + return true; + return ((old ^ new) & ~mask) == 0; } |