From mboxrd@z Thu Jan 1 00:00:00 1970 From: suzuki.poulose@arm.com (Suzuki K. Poulose) Date: Wed, 14 Oct 2015 12:20:34 +0100 Subject: [PATCHv3 11/11] arm64: 36 bit VA In-Reply-To: <1444821634-1689-1-git-send-email-suzuki.poulose@arm.com> References: <1444821634-1689-1-git-send-email-suzuki.poulose@arm.com> Message-ID: <1444821634-1689-12-git-send-email-suzuki.poulose@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 36bit VA lets us use 2 level page tables while limiting the available address space to 64GB. Cc: Mark Rutland Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Suzuki K. Poulose Reviewed-by: Ard Biesheuvel Tested-by: Ard Biesheuvel --- arch/arm64/Kconfig | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index e78045c..3b99aa9 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -170,6 +170,7 @@ config FIX_EARLYCON_MEM config PGTABLE_LEVELS int + default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 default 3 if ARM64_64K_PAGES && ARM64_VA_BITS_48 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 @@ -391,6 +392,10 @@ choice space sizes. The level of translation table is determined by a combination of page size and virtual address space size. +config ARM64_VA_BITS_36 + bool "36-bit" + depends on ARM64_16K_PAGES + config ARM64_VA_BITS_39 bool "39-bit" depends on ARM64_4K_PAGES @@ -410,6 +415,7 @@ endchoice config ARM64_VA_BITS int + default 36 if ARM64_VA_BITS_36 default 39 if ARM64_VA_BITS_39 default 42 if ARM64_VA_BITS_42 default 47 if ARM64_VA_BITS_47 @@ -480,7 +486,7 @@ config ARCH_WANT_GENERAL_HUGETLB def_bool y config ARCH_WANT_HUGE_PMD_SHARE - def_bool y if ARM64_4K_PAGES || ARM64_16K_PAGES + def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) config HAVE_ARCH_TRANSPARENT_HUGEPAGE def_bool y -- 1.7.9.5