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path: root/arch/arm64/include/asm/kernel-pgtable.h
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2016-11-21arm64: Introduce uaccess_{disable,enable} functionality based on TTBR0_EL1Catalin Marinas
This patch adds the uaccess macros/functions to disable access to user space by setting TTBR0_EL1 to a reserved zeroed page. Since the value written to TTBR0_EL1 must be a physical address, for simplicity this patch introduces a reserved_ttbr0 page at a constant offset from swapper_pg_dir. The uaccess_disable code uses the ttbr1_el1 value adjusted by the reserved_ttbr0 offset. Enabling access to user is done by restoring TTBR0_EL1 with the value from the struct thread_info ttbr0 variable. Interrupts must be disabled during the uaccess_ttbr0_enable code to ensure the atomicity of the thread_info.ttbr0 read and TTBR0_EL1 write. This patch also moves the get_thread_info asm macro from entry.S to assembler.h for reuse in the uaccess_ttbr0_* macros. Cc: Will Deacon <will.deacon@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-04-14arm64: choose memstart_addr based on minimum sparsemem section alignmentArd Biesheuvel
This redefines ARM64_MEMSTART_ALIGN in terms of the minimal alignment required by sparsemem vmemmap. This comes down to using 1 GB for all translation granules if CONFIG_SPARSEMEM_VMEMMAP is enabled. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-02-18arm64: allow kernel Image to be loaded anywhere in physical memoryArd Biesheuvel
This relaxes the kernel Image placement requirements, so that it may be placed at any 2 MB aligned offset in physical memory. This is accomplished by ignoring PHYS_OFFSET when installing memblocks, and accounting for the apparent virtual offset of the kernel Image. As a result, virtual address references below PAGE_OFFSET are correctly mapped onto physical references into the kernel Image regardless of where it sits in memory. Special care needs to be taken for dealing with memory limits passed via mem=, since the generic implementation clips memory top down, which may clip the kernel image itself if it is loaded high up in memory. To deal with this case, we simply add back the memory covering the kernel image, which may result in more memory to be retained than was passed as a mem= parameter. Since mem= should not be considered a production feature, a panic notifier handler is installed that dumps the memory limit at panic time if one was set. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-19arm64: Calculate size for idmap_pg_dir at compile timeSuzuki K. Poulose
Now that we can calculate the number of levels required for mapping a va width, reserve exact number of pages that would be required to cover the idmap. The idmap should be able to handle the maximum physical address size supported. Cc: Will Deacon <will.deacon@arm.com> 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> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-19arm64: Handle section maps for swapper/idmapSuzuki K. Poulose
We use section maps with 4K page size to create the swapper/idmaps. So far we have used !64K or 4K checks to handle the case where we use the section maps. This patch adds a new symbol, ARM64_SWAPPER_USES_SECTION_MAPS, to handle cases where we use section maps, instead of using the page size symbols. Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-19arm64: Move swapper pagetable definitionsSuzuki K. Poulose
Move the kernel pagetable (both swapper and idmap) definitions from the generic asm/page.h to a new file, asm/kernel-pgtable.h. This is mostly a cosmetic change, to clean up the asm/page.h to get rid of the arch specific details which are not needed by the generic code. Also renames the symbols to prevent conflicts. e.g, BLOCK_SHIFT => SWAPPER_BLOCK_SHIFT Cc: Will Deacon <will.deacon@arm.com> 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> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>