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| 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/include/asm/assembler.h | |
| parent | 787fd1d019b269af7912249231dfe34a5fe3e7c8 (diff) | |
| download | linux-529c4b05a3cb2f324aac347042ee6d641478e946.tar.bz2 | |
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/include/asm/assembler.h')
| -rw-r--r-- | arch/arm64/include/asm/assembler.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index 04a92307e6c1..49ea3def4bd1 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -530,4 +530,20 @@ alternative_else_nop_endif #endif .endm +/* + * Arrange a physical address in a TTBR register, taking care of 52-bit + * addresses. + * + * phys: physical address, preserved + * ttbr: returns the TTBR value + */ + .macro phys_to_ttbr, phys, ttbr +#ifdef CONFIG_ARM64_PA_BITS_52 + orr \ttbr, \phys, \phys, lsr #46 + and \ttbr, \ttbr, #TTBR_BADDR_MASK_52 +#else + mov \ttbr, \phys +#endif + .endm + #endif /* __ASM_ASSEMBLER_H */ |