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[PATCHv4 12/12] arm64: 36 bit VA

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36bit VA lets us use 2 level page tables while limiting the
available address space to 64GB.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Steve Capper <steve.capper@linaro.org>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 arch/arm64/Kconfig |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 8541664..a346671 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

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[UPDATED] [PATCHv4 00/12] arm64: 16K translation granule support "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-10-19 15:30 +0200
  [PATCHv4 03/12] arm64: Introduce helpers for page table levels "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-10-19 15:30 +0200
  [PATCHv4 01/12] arm64: Move swapper pagetable definitions "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-10-19 15:30 +0200
  [PATCHv4 11/12] arm64: Add 16K page size support "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-10-19 15:30 +0200
  [PATCHv4 10/12] arm64: Add page size to the kernel image header "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-10-19 15:30 +0200
  [PATCHv4 08/12] arm64: Kconfig: Fix help text about AArch32 support with 64K pages "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-10-19 15:30 +0200
  [PATCHv4 04/12] arm64: Calculate size for idmap_pg_dir at compile time "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-10-19 15:30 +0200
  [PATCHv4 06/12] arm64: Clean config usages for page size "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-10-19 15:30 +0200
  [PATCHv4 12/12] arm64: 36 bit VA "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-10-19 15:30 +0200
  [PATCHv4 09/12] arm64: Check for selected granule support "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-10-19 15:30 +0200
  Re: [UPDATED] [PATCHv4 00/12] arm64: 16K translation granule support Mark Rutland <mark.rutland@arm.com> - 2015-10-19 18:40 +0200
  Re: [UPDATED] [PATCHv4 00/12] arm64: 16K translation granule support Catalin Marinas <catalin.marinas@arm.com> - 2015-10-19 19:40 +0200
    Re: [UPDATED] [PATCHv4 00/12] arm64: 16K translation granule support "Suzuki K. Poulose" <Suzuki.Poulose@arm.com> - 2015-10-19 19:50 +0200

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