diff options
| author | Kristina Martsenko <kristina.martsenko@arm.com> | 2017-12-13 17:07:18 +0000 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2017-12-22 17:35:21 +0000 |
| commit | 529c4b05a3cb2f324aac347042ee6d641478e946 (patch) | |
| tree | 2fab0e91f3abe37f2b7ee29a02e0c41af6ad03d6 /arch/arm64/mm/pgd.c | |
| parent | 787fd1d019b269af7912249231dfe34a5fe3e7c8 (diff) | |
arm64: handle 52-bit addresses in TTBR
The top 4 bits of a 52-bit physical address are positioned at bits 2..5
in the TTBR registers. Introduce a couple of macros to move the bits
there, and change all TTBR writers to use them.
Leave TTBR0 PAN code unchanged, to avoid complicating it. A system with
52-bit PA will have PAN anyway (because it's ARMv8.1 or later), and a
system without 52-bit PA can only use up to 48-bit PAs. A later patch in
this series will add a kconfig dependency to ensure PAN is configured.
In addition, when using 52-bit PA there is a special alignment
requirement on the top-level table. We don't currently have any VA_BITS
configuration that would violate the requirement, but one could be added
in the future, so add a compile-time BUG_ON to check for it.
Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Bob Picco <bob.picco@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
[catalin.marinas@arm.com: added TTBR_BADD_MASK_52 comment]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/mm/pgd.c')
| -rw-r--r-- | arch/arm64/mm/pgd.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/arm64/mm/pgd.c b/arch/arm64/mm/pgd.c index 051e71ec3335..289f9113a27a 100644 --- a/arch/arm64/mm/pgd.c +++ b/arch/arm64/mm/pgd.c @@ -49,6 +49,14 @@ void __init pgd_cache_init(void) if (PGD_SIZE == PAGE_SIZE) return; +#ifdef CONFIG_ARM64_PA_BITS_52 + /* + * With 52-bit physical addresses, the architecture requires the + * top-level table to be aligned to at least 64 bytes. + */ + BUILD_BUG_ON(PGD_SIZE < 64); +#endif + /* * Naturally aligned pgds required by the architecture. */ |