kernel/linux.git/arch/arm64/include/asm/memory.h, branch linux-5.9.y

arm64: mm: use single quantity to represent the PA to VA translation

2020-10-29T09:11:59+00:00

[ Upstream commit 7bc1a0f9e1765830e945669c99c59c35cf9bca82 ] On arm64, the global variable memstart_addr represents the physical address of PAGE_OFFSET, and so physical to virtual translations or vice versa used to come down to simple additions or subtractions involving the values of PAGE_OFFSET and memstart_addr. When support for 52-bit virtual addressing was introduced, we had to deal with PAGE_OFFSET potentially being outside of the region that can be covered by the virtual range (as the 52-bit VA capable build needs to be able to run on systems that are only 48-bit VA capable), and for this reason, another translation was introduced, and recorded in the global variable physvirt_offset. However, if we go back to the original definition of memstart_addr, i.e., the physical address of PAGE_OFFSET, it turns out that there is no need for two separate translations: instead, we can simply subtract the size of the unaddressable VA space from memstart_addr to make the available physical memory appear in the 48-bit addressable VA region. This simplifies things, but also fixes a bug on KASLR builds, which may update memstart_addr later on in arm64_memblock_init(), but fails to update vmemmap and physvirt_offset accordingly. Fixes: 5383cc6efed1 ("arm64: mm: Introduce vabits_actual") Signed-off-by: Ard Biesheuvel Reviewed-by: Steve Capper Link: https://lore.kernel.org/r/20201008153602.9467-2-ardb@kernel.org Signed-off-by: Will Deacon Signed-off-by: Sasha Levin

Merge branch 'for-next/read-barrier-depends' into for-next/core

2020-07-31T17:09:57+00:00

* for-next/read-barrier-depends: : Allow architectures to override __READ_ONCE() arm64: Reduce the number of header files pulled into vmlinux.lds.S compiler.h: Move compiletime_assert() macros into compiler_types.h checkpatch: Remove checks relating to [smp_]read_barrier_depends() include/linux: Remove smp_read_barrier_depends() from comments tools/memory-model: Remove smp_read_barrier_depends() from informal doc Documentation/barriers/kokr: Remove references to [smp_]read_barrier_depends() Documentation/barriers: Remove references to [smp_]read_barrier_depends() locking/barriers: Remove definitions for [smp_]read_barrier_depends() alpha: Replace smp_read_barrier_depends() usage with smp_[r]mb() vhost: Remove redundant use of read_barrier_depends() barrier asm/rwonce: Don't pull into 'asm-generic/rwonce.h' asm/rwonce: Remove smp_read_barrier_depends() invocation alpha: Override READ_ONCE() with barriered implementation asm/rwonce: Allow __READ_ONCE to be overridden by the architecture compiler.h: Split {READ,WRITE}_ONCE definitions out into rwonce.h tools: bpf: Use local copy of headers including uapi/linux/filter.h

arm64: Reduce the number of header files pulled into vmlinux.lds.S

2020-07-21T09:50:37+00:00

Although vmlinux.lds.S smells like an assembly file and is compiled with __ASSEMBLY__ defined, it's actually just fed to the preprocessor to create our linker script. This means that any assembly macros defined by headers that it includes will result in a helpful link error: | aarch64-linux-gnu-ld:./arch/arm64/kernel/vmlinux.lds:1: syntax error In preparation for an arm64-private asm/rwonce.h implementation, which will end up pulling assembly macros into linux/compiler.h, reduce the number of headers we include directly and transitively in vmlinux.lds.S Acked-by: Peter Zijlstra (Intel) Signed-off-by: Will Deacon

arm64/panic: Unify all three existing notifier blocks

2020-07-02T14:44:50+00:00

Currently there are three different registered panic notifier blocks. This unifies all of them into a single one i.e arm64_panic_block, hence reducing code duplication and required calling sequence during panic. This preserves the existing dump sequence. While here, just use device_initcall() directly instead of __initcall() which has been a legacy alias for the earlier. This replacement is a pure cleanup with no functional implications. Signed-off-by: Anshuman Khandual Acked-by: Mark Rutland Cc: Will Deacon Cc: Steve Capper Cc: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/1593405511-7625-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Catalin Marinas

arm64: remove CONFIG_DEBUG_ALIGN_RODATA feature

2020-04-01T20:44:43+00:00

When CONFIG_DEBUG_ALIGN_RODATA is enabled, kernel segments mapped with different permissions (r-x for .text, r-- for .rodata, rw- for .data, etc) are rounded up to 2 MiB so they can be mapped more efficiently. In particular, it permits the segments to be mapped using level 2 block entries when using 4k pages, which is expected to result in less TLB pressure. However, the mappings for the bulk of the kernel will use level 2 entries anyway, and the misaligned fringes are organized such that they can take advantage of the contiguous bit, and use far fewer level 3 entries than would be needed otherwise. This makes the value of this feature dubious at best, and since it is not enabled in defconfig or in the distro configs, it does not appear to be in wide use either. So let's just remove it. Signed-off-by: Ard Biesheuvel Acked-by: Mark Rutland Acked-by: Will Deacon Acked-by: Laura Abbott Signed-off-by: Catalin Marinas

arm64/mm: Enable memory hot remove

2020-03-04T15:35:44+00:00

The arch code for hot-remove must tear down portions of the linear map and vmemmap corresponding to memory being removed. In both cases the page tables mapping these regions must be freed, and when sparse vmemmap is in use the memory backing the vmemmap must also be freed. This patch adds unmap_hotplug_range() and free_empty_tables() helpers which can be used to tear down either region and calls it from vmemmap_free() and ___remove_pgd_mapping(). The free_mapped argument determines whether the backing memory will be freed. It makes two distinct passes over the kernel page table. In the first pass with unmap_hotplug_range() it unmaps, invalidates applicable TLB cache and frees backing memory if required (vmemmap) for each mapped leaf entry. In the second pass with free_empty_tables() it looks for empty page table sections whose page table page can be unmapped, TLB invalidated and freed. While freeing intermediate level page table pages bail out if any of its entries are still valid. This can happen for partially filled kernel page table either from a previously attempted failed memory hot add or while removing an address range which does not span the entire page table page range. The vmemmap region may share levels of table with the vmalloc region. There can be conflicts between hot remove freeing page table pages with a concurrent vmalloc() walking the kernel page table. This conflict can not just be solved by taking the init_mm ptl because of existing locking scheme in vmalloc(). So free_empty_tables() implements a floor and ceiling method which is borrowed from user page table tear with free_pgd_range() which skips freeing page table pages if intermediate address range is not aligned or maximum floor-ceiling might not own the entire page table page. Boot memory on arm64 cannot be removed. Hence this registers a new memory hotplug notifier which prevents boot memory offlining and it's removal. While here update arch_add_memory() to handle __add_pages() failures by just unmapping recently added kernel linear mapping. Now enable memory hot remove on arm64 platforms by default with ARCH_ENABLE_MEMORY_HOTREMOVE. This implementation is overall inspired from kernel page table tear down procedure on X86 architecture and user page table tear down method. [Mike and Catalin added P4D page table level support] Reviewed-by: Catalin Marinas Signed-off-by: Mike Rapoport Signed-off-by: Catalin Marinas Signed-off-by: Anshuman Khandual Signed-off-by: Catalin Marinas

arm64: memory: Add missing brackets to untagged_addr() macro

2020-02-19T13:41:33+00:00

Add brackets around the evaluation of the 'addr' parameter to the untagged_addr() macro so that the cast to 'u64' applies to the result of the expression. Cc: Fixes: 597399d0cb91 ("arm64: tags: Preserve tags for addresses translated via TTBR1") Reported-by: Linus Torvalds Signed-off-by: Will Deacon

Merge branches 'for-next/elf-hwcap-docs', 'for-next/smccc-conduit-cleanup', 'for-next/zone-dma', 'for-next/relax-icc_pmr_el1-sync', 'for-next/double-page-fault', 'for-next/misc', 'for-next/kselftest-arm64-signal' and 'for-next/kaslr-diagnostics' into for-next/core

2019-11-08T17:46:11+00:00

* for-next/elf-hwcap-docs: : Update the arm64 ELF HWCAP documentation docs/arm64: cpu-feature-registers: Rewrite bitfields that don't follow [e, s] docs/arm64: cpu-feature-registers: Documents missing visible fields docs/arm64: elf_hwcaps: Document HWCAP_SB docs/arm64: elf_hwcaps: sort the HWCAP{, 2} documentation by ascending value * for-next/smccc-conduit-cleanup: : SMC calling convention conduit clean-up firmware: arm_sdei: use common SMCCC_CONDUIT_* firmware/psci: use common SMCCC_CONDUIT_* arm: spectre-v2: use arm_smccc_1_1_get_conduit() arm64: errata: use arm_smccc_1_1_get_conduit() arm/arm64: smccc/psci: add arm_smccc_1_1_get_conduit() * for-next/zone-dma: : Reintroduction of ZONE_DMA for Raspberry Pi 4 support arm64: mm: reserve CMA and crashkernel in ZONE_DMA32 dma/direct: turn ARCH_ZONE_DMA_BITS into a variable arm64: Make arm64_dma32_phys_limit static arm64: mm: Fix unused variable warning in zone_sizes_init mm: refresh ZONE_DMA and ZONE_DMA32 comments in 'enum zone_type' arm64: use both ZONE_DMA and ZONE_DMA32 arm64: rename variables used to calculate ZONE_DMA32's size arm64: mm: use arm64_dma_phys_limit instead of calling max_zone_dma_phys() * for-next/relax-icc_pmr_el1-sync: : Relax ICC_PMR_EL1 (GICv3) accesses when ICC_CTLR_EL1.PMHE is clear arm64: Document ICC_CTLR_EL3.PMHE setting requirements arm64: Relax ICC_PMR_EL1 accesses when ICC_CTLR_EL1.PMHE is clear * for-next/double-page-fault: : Avoid a double page fault in __copy_from_user_inatomic() if hw does not support auto Access Flag mm: fix double page fault on arm64 if PTE_AF is cleared x86/mm: implement arch_faults_on_old_pte() stub on x86 arm64: mm: implement arch_faults_on_old_pte() on arm64 arm64: cpufeature: introduce helper cpu_has_hw_af() * for-next/misc: : Various fixes and clean-ups arm64: kpti: Add NVIDIA's Carmel core to the KPTI whitelist arm64: mm: Remove MAX_USER_VA_BITS definition arm64: mm: simplify the page end calculation in __create_pgd_mapping() arm64: print additional fault message when executing non-exec memory arm64: psci: Reduce the waiting time for cpu_psci_cpu_kill() arm64: pgtable: Correct typo in comment arm64: docs: cpu-feature-registers: Document ID_AA64PFR1_EL1 arm64: cpufeature: Fix typos in comment arm64/mm: Poison initmem while freeing with free_reserved_area() arm64: use generic free_initrd_mem() arm64: simplify syscall wrapper ifdeffery * for-next/kselftest-arm64-signal: : arm64-specific kselftest support with signal-related test-cases kselftest: arm64: fake_sigreturn_misaligned_sp kselftest: arm64: fake_sigreturn_bad_size kselftest: arm64: fake_sigreturn_duplicated_fpsimd kselftest: arm64: fake_sigreturn_missing_fpsimd kselftest: arm64: fake_sigreturn_bad_size_for_magic0 kselftest: arm64: fake_sigreturn_bad_magic kselftest: arm64: add helper get_current_context kselftest: arm64: extend test_init functionalities kselftest: arm64: mangle_pstate_invalid_mode_el[123][ht] kselftest: arm64: mangle_pstate_invalid_daif_bits kselftest: arm64: mangle_pstate_invalid_compat_toggle and common utils kselftest: arm64: extend toplevel skeleton Makefile * for-next/kaslr-diagnostics: : Provide diagnostics on boot for KASLR arm64: kaslr: Check command line before looking for a seed arm64: kaslr: Announce KASLR status on boot

arm64: mm: Remove MAX_USER_VA_BITS definition

2019-11-06T11:19:25+00:00

commit 9b31cf493ffa ("arm64: mm: Introduce MAX_USER_VA_BITS definition") introduced the MAX_USER_VA_BITS definition, which was used to support the arm64 mm use-cases where the user-space could use 52-bit virtual addresses whereas the kernel-space would still could a maximum of 48-bit virtual addressing. But, now with commit b6d00d47e81a ("arm64: mm: Introduce 52-bit Kernel VAs"), we removed the 52-bit user/48-bit kernel kconfig option and hence there is no longer any scenario where user VA != kernel VA size (even with CONFIG_ARM64_FORCE_52BIT enabled, the same is true). Hence we can do away with the MAX_USER_VA_BITS macro as it is equal to VA_BITS (maximum VA space size) in all possible use-cases. Note that even though the 'vabits_actual' value would be 48 for arm64 hardware which don't support LVA-8.2 extension (even when CONFIG_ARM64_VA_BITS_52 is enabled), VA_BITS would still be set to a value 52. Hence this change would be safe in all possible VA address space combinations. Cc: James Morse Cc: Will Deacon Cc: Steve Capper Cc: Ard Biesheuvel Cc: linux-kernel@vger.kernel.org Cc: kexec@lists.infradead.org Reviewed-by: Mark Rutland Signed-off-by: Bhupesh Sharma Signed-off-by: Catalin Marinas

arm64: tags: Preserve tags for addresses translated via TTBR1

2019-10-16T17:11:38+00:00

Sign-extending TTBR1 addresses when converting to an untagged address breaks the documented POSIX semantics for mlock() in some obscure error cases where we end up returning -EINVAL instead of -ENOMEM as a direct result of rewriting the upper address bits. Rework the untagged_addr() macro to preserve the upper address bits for TTBR1 addresses and only clear the tag bits for user addresses. This matches the behaviour of the 'clear_address_tag' assembly macro, so rename that and align the implementations at the same time so that they use the same instruction sequences for the tag manipulation. Link: https://lore.kernel.org/stable/20191014162651.GF19200@arrakis.emea.arm.com/ Reported-by: Jan Stancek Tested-by: Jan Stancek Reviewed-by: Catalin Marinas Tested-by: Catalin Marinas Reviewed-by: Vincenzo Frascino Tested-by: Vincenzo Frascino Reviewed-by: Andrey Konovalov Signed-off-by: Will Deacon