This patch series brings support for 52-bit userspace VAs to systems that have ARMv8.2-LVA and are running with a 48-bit VA_BITS and a 64KB PAGE_SIZE. If no hardware support is present, the kernel runs with a 48-bit VA space for userspace. Userspace can exploit this feature by providing an address hint to mmap where addr[51:48] != 0. Otherwise all the VA mappings will behave in the same way as a 48-bit VA system (this is to maintain compatibility with software that assumes the maximum VA size on arm64 is 48-bit). This patch series applies to 4.20-rc1. Testing was in a model with Trusted Firmware and UEFI for boot. Changed in V4, pgd_index changes dropped in favour of offsetting the ttbr1. This is performed in a new patch, #4. Changed in V3, COMPAT fixes added (and tested with 32-bit userspace code). Extra patch added to allow forcing all userspace allocations to come from 52-bits (to allow for debugging and testing). The major change to V2 of the series is that mm/mmap.c is altered in the first patch of the series (rather than copied over to arch/arm64). Steve Capper (6): mm: mmap: Allow for "high" userspace addresses arm64: mm: Introduce DEFAULT_MAP_WINDOW arm64: mm: Define arch_get_mmap_end, arch_get_mmap_base arm64: mm: Offset TTBR1 to allow 52-bit PTRS_PER_PGD arm64: mm: introduce 52-bit userspace support arm64: mm: Allow forcing all userspace addresses to 52-bit arch/arm64/Kconfig | 17 ++++++++++++ arch/arm64/include/asm/asm-uaccess.h | 4 +++ arch/arm64/include/asm/assembler.h | 30 ++++++++++++++++++--- arch/arm64/include/asm/elf.h | 4 +++ arch/arm64/include/asm/mmu_context.h | 3 +++ arch/arm64/include/asm/pgtable-hwdef.h | 9 +++++++ arch/arm64/include/asm/processor.h | 36 ++++++++++++++++++++----- arch/arm64/include/asm/uaccess.h | 4 +++ arch/arm64/kernel/head.S | 14 ++++++++++ arch/arm64/kernel/hibernate-asm.S | 1 + arch/arm64/mm/fault.c | 2 +- arch/arm64/mm/init.c | 2 +- arch/arm64/mm/mmu.c | 1 + arch/arm64/mm/proc.S | 14 +++++++++- drivers/firmware/efi/arm-runtime.c | 2 +- drivers/firmware/efi/libstub/arm-stub.c | 2 +- mm/mmap.c | 25 ++++++++++++----- 17 files changed, 148 insertions(+), 22 deletions(-) -- 2.19.2
