Commit f77d2817 authored Dec 13, 2017 by Kristina Martsenko Committed by Catalin Marinas Dec 22, 2017

arm64: enable 52-bit physical address support



Now that 52-bit physical address support is in place, add the kconfig
symbol to enable it. As described in ARMv8.2, the larger addresses are
only supported with the 64k granule. Also ensure that PAN is configured
(or TTBR0 PAN is not), as explained in an earlier patch in this series.

Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-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>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

parent fa2a8445

arch/arm64/Kconfig

+13 −0

Original line number	Diff line number	Diff line
		@@ -656,11 +656,24 @@ choice
		config ARM64_PA_BITS_48
		bool "48-bit"

		config ARM64_PA_BITS_52
		bool "52-bit (ARMv8.2)"
		depends on ARM64_64K_PAGES
		depends on ARM64_PAN \|\| !ARM64_SW_TTBR0_PAN
		help
		Enable support for a 52-bit physical address space, introduced as
		part of the ARMv8.2-LPA extension.

		With this enabled, the kernel will also continue to work on CPUs that
		do not support ARMv8.2-LPA, but with some added memory overhead (and
		minor performance overhead).

		endchoice

		config ARM64_PA_BITS
		int
		default 48 if ARM64_PA_BITS_48
		default 52 if ARM64_PA_BITS_52

		config CPU_BIG_ENDIAN
		bool "Build big-endian kernel"

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