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-rw-r--r--arch/arm64/Kconfig2336
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diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
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--- /dev/null
+++ b/arch/arm64/Kconfig
@@ -0,0 +1,2336 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config ARM64
+ def_bool y
+ select ACPI_APMT if ACPI
+ select ACPI_CCA_REQUIRED if ACPI
+ select ACPI_GENERIC_GSI if ACPI
+ select ACPI_GTDT if ACPI
+ select ACPI_IORT if ACPI
+ select ACPI_REDUCED_HARDWARE_ONLY if ACPI
+ select ACPI_MCFG if (ACPI && PCI)
+ select ACPI_SPCR_TABLE if ACPI
+ select ACPI_PPTT if ACPI
+ select ARCH_HAS_DEBUG_WX
+ select ARCH_BINFMT_ELF_EXTRA_PHDRS
+ select ARCH_BINFMT_ELF_STATE
+ select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
+ select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
+ select ARCH_ENABLE_MEMORY_HOTPLUG
+ select ARCH_ENABLE_MEMORY_HOTREMOVE
+ select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
+ select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
+ select ARCH_HAS_CACHE_LINE_SIZE
+ select ARCH_HAS_CURRENT_STACK_POINTER
+ select ARCH_HAS_DEBUG_VIRTUAL
+ select ARCH_HAS_DEBUG_VM_PGTABLE
+ select ARCH_HAS_DMA_PREP_COHERENT
+ select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
+ select ARCH_HAS_FAST_MULTIPLIER
+ select ARCH_HAS_FORTIFY_SOURCE
+ select ARCH_HAS_GCOV_PROFILE_ALL
+ select ARCH_HAS_GIGANTIC_PAGE
+ select ARCH_HAS_KCOV
+ select ARCH_HAS_KEEPINITRD
+ select ARCH_HAS_MEMBARRIER_SYNC_CORE
+ select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
+ select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+ select ARCH_HAS_PTE_DEVMAP
+ select ARCH_HAS_PTE_SPECIAL
+ select ARCH_HAS_SETUP_DMA_OPS
+ select ARCH_HAS_SET_DIRECT_MAP
+ select ARCH_HAS_SET_MEMORY
+ select ARCH_STACKWALK
+ select ARCH_HAS_STRICT_KERNEL_RWX
+ select ARCH_HAS_STRICT_MODULE_RWX
+ select ARCH_HAS_SYNC_DMA_FOR_DEVICE
+ select ARCH_HAS_SYNC_DMA_FOR_CPU
+ select ARCH_HAS_SYSCALL_WRAPPER
+ select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT
+ select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
+ select ARCH_HAS_ZONE_DMA_SET if EXPERT
+ select ARCH_HAVE_ELF_PROT
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG
+ select ARCH_HAVE_TRACE_MMIO_ACCESS
+ select ARCH_INLINE_READ_LOCK if !PREEMPTION
+ select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
+ select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
+ select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
+ select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
+ select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
+ select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
+ select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
+ select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
+ select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
+ select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
+ select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
+ select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
+ select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
+ select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
+ select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
+ select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
+ select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
+ select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
+ select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
+ select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
+ select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
+ select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
+ select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
+ select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
+ select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
+ select ARCH_KEEP_MEMBLOCK
+ select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
+ select ARCH_USE_CMPXCHG_LOCKREF
+ select ARCH_USE_GNU_PROPERTY
+ select ARCH_USE_MEMTEST
+ select ARCH_USE_QUEUED_RWLOCKS
+ select ARCH_USE_QUEUED_SPINLOCKS
+ select ARCH_USE_SYM_ANNOTATIONS
+ select ARCH_SUPPORTS_DEBUG_PAGEALLOC
+ select ARCH_SUPPORTS_HUGETLBFS
+ select ARCH_SUPPORTS_MEMORY_FAILURE
+ select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
+ select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
+ select ARCH_SUPPORTS_LTO_CLANG_THIN
+ select ARCH_SUPPORTS_CFI_CLANG
+ select ARCH_SUPPORTS_ATOMIC_RMW
+ select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
+ select ARCH_SUPPORTS_NUMA_BALANCING
+ select ARCH_SUPPORTS_PAGE_TABLE_CHECK
+ select ARCH_SUPPORTS_PER_VMA_LOCK
+ select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
+ select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
+ select ARCH_WANT_DEFAULT_BPF_JIT
+ select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
+ select ARCH_WANT_FRAME_POINTERS
+ select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
+ select ARCH_WANT_LD_ORPHAN_WARN
+ select ARCH_WANTS_NO_INSTR
+ select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
+ select ARCH_HAS_UBSAN_SANITIZE_ALL
+ select ARM_AMBA
+ select ARM_ARCH_TIMER
+ select ARM_GIC
+ select AUDIT_ARCH_COMPAT_GENERIC
+ select ARM_GIC_V2M if PCI
+ select ARM_GIC_V3
+ select ARM_GIC_V3_ITS if PCI
+ select ARM_PSCI_FW
+ select BUILDTIME_TABLE_SORT
+ select CLONE_BACKWARDS
+ select COMMON_CLK
+ select CPU_PM if (SUSPEND || CPU_IDLE)
+ select CRC32
+ select DCACHE_WORD_ACCESS
+ select DYNAMIC_FTRACE if FUNCTION_TRACER
+ select DMA_BOUNCE_UNALIGNED_KMALLOC
+ select DMA_DIRECT_REMAP
+ select EDAC_SUPPORT
+ select FRAME_POINTER
+ select FUNCTION_ALIGNMENT_4B
+ select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
+ select GENERIC_ALLOCATOR
+ select GENERIC_ARCH_TOPOLOGY
+ select GENERIC_CLOCKEVENTS_BROADCAST
+ select GENERIC_CPU_AUTOPROBE
+ select GENERIC_CPU_VULNERABILITIES
+ select GENERIC_EARLY_IOREMAP
+ select GENERIC_IDLE_POLL_SETUP
+ select GENERIC_IOREMAP
+ select GENERIC_IRQ_IPI
+ select GENERIC_IRQ_PROBE
+ select GENERIC_IRQ_SHOW
+ select GENERIC_IRQ_SHOW_LEVEL
+ select GENERIC_LIB_DEVMEM_IS_ALLOWED
+ select GENERIC_PCI_IOMAP
+ select GENERIC_PTDUMP
+ select GENERIC_SCHED_CLOCK
+ select GENERIC_SMP_IDLE_THREAD
+ select GENERIC_TIME_VSYSCALL
+ select GENERIC_GETTIMEOFDAY
+ select GENERIC_VDSO_TIME_NS
+ select HARDIRQS_SW_RESEND
+ select HAS_IOPORT
+ select HAVE_MOVE_PMD
+ select HAVE_MOVE_PUD
+ select HAVE_PCI
+ select HAVE_ACPI_APEI if (ACPI && EFI)
+ select HAVE_ALIGNED_STRUCT_PAGE if SLUB
+ select HAVE_ARCH_AUDITSYSCALL
+ select HAVE_ARCH_BITREVERSE
+ select HAVE_ARCH_COMPILER_H
+ select HAVE_ARCH_HUGE_VMALLOC
+ select HAVE_ARCH_HUGE_VMAP
+ select HAVE_ARCH_JUMP_LABEL
+ select HAVE_ARCH_JUMP_LABEL_RELATIVE
+ select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
+ select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
+ select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
+ select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE)
+ # Some instrumentation may be unsound, hence EXPERT
+ select HAVE_ARCH_KCSAN if EXPERT
+ select HAVE_ARCH_KFENCE
+ select HAVE_ARCH_KGDB
+ select HAVE_ARCH_MMAP_RND_BITS
+ select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
+ select HAVE_ARCH_PREL32_RELOCATIONS
+ select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
+ select HAVE_ARCH_SECCOMP_FILTER
+ select HAVE_ARCH_STACKLEAK
+ select HAVE_ARCH_THREAD_STRUCT_WHITELIST
+ select HAVE_ARCH_TRACEHOOK
+ select HAVE_ARCH_TRANSPARENT_HUGEPAGE
+ select HAVE_ARCH_VMAP_STACK
+ select HAVE_ARM_SMCCC
+ select HAVE_ASM_MODVERSIONS
+ select HAVE_EBPF_JIT
+ select HAVE_C_RECORDMCOUNT
+ select HAVE_CMPXCHG_DOUBLE
+ select HAVE_CMPXCHG_LOCAL
+ select HAVE_CONTEXT_TRACKING_USER
+ select HAVE_DEBUG_KMEMLEAK
+ select HAVE_DMA_CONTIGUOUS
+ select HAVE_DYNAMIC_FTRACE
+ select HAVE_DYNAMIC_FTRACE_WITH_ARGS \
+ if $(cc-option,-fpatchable-function-entry=2)
+ select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
+ if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS
+ select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
+ if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \
+ !CC_OPTIMIZE_FOR_SIZE)
+ select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
+ if DYNAMIC_FTRACE_WITH_ARGS
+ select HAVE_SAMPLE_FTRACE_DIRECT
+ select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
+ select HAVE_EFFICIENT_UNALIGNED_ACCESS
+ select HAVE_FAST_GUP
+ select HAVE_FTRACE_MCOUNT_RECORD
+ select HAVE_FUNCTION_TRACER
+ select HAVE_FUNCTION_ERROR_INJECTION
+ select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
+ select HAVE_FUNCTION_GRAPH_TRACER
+ select HAVE_GCC_PLUGINS
+ select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
+ HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
+ select HAVE_HW_BREAKPOINT if PERF_EVENTS
+ select HAVE_IOREMAP_PROT
+ select HAVE_IRQ_TIME_ACCOUNTING
+ select HAVE_KVM
+ select HAVE_MOD_ARCH_SPECIFIC
+ select HAVE_NMI
+ select HAVE_PERF_EVENTS
+ select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
+ select HAVE_PERF_REGS
+ select HAVE_PERF_USER_STACK_DUMP
+ select HAVE_PREEMPT_DYNAMIC_KEY
+ select HAVE_REGS_AND_STACK_ACCESS_API
+ select HAVE_POSIX_CPU_TIMERS_TASK_WORK
+ select HAVE_FUNCTION_ARG_ACCESS_API
+ select MMU_GATHER_RCU_TABLE_FREE
+ select HAVE_RSEQ
+ select HAVE_STACKPROTECTOR
+ select HAVE_SYSCALL_TRACEPOINTS
+ select HAVE_KPROBES
+ select HAVE_KRETPROBES
+ select HAVE_GENERIC_VDSO
+ select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
+ select IRQ_DOMAIN
+ select IRQ_FORCED_THREADING
+ select KASAN_VMALLOC if KASAN
+ select LOCK_MM_AND_FIND_VMA
+ select MODULES_USE_ELF_RELA
+ select NEED_DMA_MAP_STATE
+ select NEED_SG_DMA_LENGTH
+ select OF
+ select OF_EARLY_FLATTREE
+ select PCI_DOMAINS_GENERIC if PCI
+ select PCI_ECAM if (ACPI && PCI)
+ select PCI_SYSCALL if PCI
+ select POWER_RESET
+ select POWER_SUPPLY
+ select SPARSE_IRQ
+ select SWIOTLB
+ select SYSCTL_EXCEPTION_TRACE
+ select THREAD_INFO_IN_TASK
+ select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
+ select TRACE_IRQFLAGS_SUPPORT
+ select TRACE_IRQFLAGS_NMI_SUPPORT
+ select HAVE_SOFTIRQ_ON_OWN_STACK
+ help
+ ARM 64-bit (AArch64) Linux support.
+
+config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
+ def_bool CC_IS_CLANG
+ # https://github.com/ClangBuiltLinux/linux/issues/1507
+ depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
+ select HAVE_DYNAMIC_FTRACE_WITH_ARGS
+
+config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
+ def_bool CC_IS_GCC
+ depends on $(cc-option,-fpatchable-function-entry=2)
+ select HAVE_DYNAMIC_FTRACE_WITH_ARGS
+
+config 64BIT
+ def_bool y
+
+config MMU
+ def_bool y
+
+config ARM64_PAGE_SHIFT
+ int
+ default 16 if ARM64_64K_PAGES
+ default 14 if ARM64_16K_PAGES
+ default 12
+
+config ARM64_CONT_PTE_SHIFT
+ int
+ default 5 if ARM64_64K_PAGES
+ default 7 if ARM64_16K_PAGES
+ default 4
+
+config ARM64_CONT_PMD_SHIFT
+ int
+ default 5 if ARM64_64K_PAGES
+ default 5 if ARM64_16K_PAGES
+ default 4
+
+config ARCH_MMAP_RND_BITS_MIN
+ default 14 if ARM64_64K_PAGES
+ default 16 if ARM64_16K_PAGES
+ default 18
+
+# max bits determined by the following formula:
+# VA_BITS - PAGE_SHIFT - 3
+config ARCH_MMAP_RND_BITS_MAX
+ default 19 if ARM64_VA_BITS=36
+ default 24 if ARM64_VA_BITS=39
+ default 27 if ARM64_VA_BITS=42
+ default 30 if ARM64_VA_BITS=47
+ default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
+ default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
+ default 33 if ARM64_VA_BITS=48
+ default 14 if ARM64_64K_PAGES
+ default 16 if ARM64_16K_PAGES
+ default 18
+
+config ARCH_MMAP_RND_COMPAT_BITS_MIN
+ default 7 if ARM64_64K_PAGES
+ default 9 if ARM64_16K_PAGES
+ default 11
+
+config ARCH_MMAP_RND_COMPAT_BITS_MAX
+ default 16
+
+config NO_IOPORT_MAP
+ def_bool y if !PCI
+
+config STACKTRACE_SUPPORT
+ def_bool y
+
+config ILLEGAL_POINTER_VALUE
+ hex
+ default 0xdead000000000000
+
+config LOCKDEP_SUPPORT
+ def_bool y
+
+config GENERIC_BUG
+ def_bool y
+ depends on BUG
+
+config GENERIC_BUG_RELATIVE_POINTERS
+ def_bool y
+ depends on GENERIC_BUG
+
+config GENERIC_HWEIGHT
+ def_bool y
+
+config GENERIC_CSUM
+ def_bool y
+
+config GENERIC_CALIBRATE_DELAY
+ def_bool y
+
+config SMP
+ def_bool y
+
+config KERNEL_MODE_NEON
+ def_bool y
+
+config FIX_EARLYCON_MEM
+ def_bool y
+
+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 || ARM64_VA_BITS_52)
+ default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
+ default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
+ default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
+
+config ARCH_SUPPORTS_UPROBES
+ def_bool y
+
+config ARCH_PROC_KCORE_TEXT
+ def_bool y
+
+config BROKEN_GAS_INST
+ def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
+
+config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
+ bool
+ # Clang's __builtin_return_adddress() strips the PAC since 12.0.0
+ # https://reviews.llvm.org/D75044
+ default y if CC_IS_CLANG && (CLANG_VERSION >= 120000)
+ # GCC's __builtin_return_address() strips the PAC since 11.1.0,
+ # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
+ # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
+ default y if CC_IS_GCC && (GCC_VERSION >= 110100)
+ default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
+ default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000)
+ default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000)
+ default n
+
+config KASAN_SHADOW_OFFSET
+ hex
+ depends on KASAN_GENERIC || KASAN_SW_TAGS
+ default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS
+ default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS
+ default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
+ default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
+ default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
+ default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS
+ default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS
+ default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
+ default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
+ default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
+ default 0xffffffffffffffff
+
+config UNWIND_TABLES
+ bool
+
+source "arch/arm64/Kconfig.platforms"
+
+menu "Kernel Features"
+
+menu "ARM errata workarounds via the alternatives framework"
+
+config AMPERE_ERRATUM_AC03_CPU_38
+ bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics"
+ default y
+ help
+ This option adds an alternative code sequence to work around Ampere
+ erratum AC03_CPU_38 on AmpereOne.
+
+ The affected design reports FEAT_HAFDBS as not implemented in
+ ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
+ as required by the architecture. The unadvertised HAFDBS
+ implementation suffers from an additional erratum where hardware
+ A/D updates can occur after a PTE has been marked invalid.
+
+ The workaround forces KVM to explicitly set VTCR_EL2.HA to 0,
+ which avoids enabling unadvertised hardware Access Flag management
+ at stage-2.
+
+ If unsure, say Y.
+
+config ARM64_WORKAROUND_CLEAN_CACHE
+ bool
+
+config ARM64_ERRATUM_826319
+ bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
+ default y
+ select ARM64_WORKAROUND_CLEAN_CACHE
+ help
+ This option adds an alternative code sequence to work around ARM
+ erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
+ AXI master interface and an L2 cache.
+
+ If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
+ and is unable to accept a certain write via this interface, it will
+ not progress on read data presented on the read data channel and the
+ system can deadlock.
+
+ The workaround promotes data cache clean instructions to
+ data cache clean-and-invalidate.
+ Please note that this does not necessarily enable the workaround,
+ as it depends on the alternative framework, which will only patch
+ the kernel if an affected CPU is detected.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_827319
+ bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
+ default y
+ select ARM64_WORKAROUND_CLEAN_CACHE
+ help
+ This option adds an alternative code sequence to work around ARM
+ erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
+ master interface and an L2 cache.
+
+ Under certain conditions this erratum can cause a clean line eviction
+ to occur at the same time as another transaction to the same address
+ on the AMBA 5 CHI interface, which can cause data corruption if the
+ interconnect reorders the two transactions.
+
+ The workaround promotes data cache clean instructions to
+ data cache clean-and-invalidate.
+ Please note that this does not necessarily enable the workaround,
+ as it depends on the alternative framework, which will only patch
+ the kernel if an affected CPU is detected.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_824069
+ bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
+ default y
+ select ARM64_WORKAROUND_CLEAN_CACHE
+ help
+ This option adds an alternative code sequence to work around ARM
+ erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
+ to a coherent interconnect.
+
+ If a Cortex-A53 processor is executing a store or prefetch for
+ write instruction at the same time as a processor in another
+ cluster is executing a cache maintenance operation to the same
+ address, then this erratum might cause a clean cache line to be
+ incorrectly marked as dirty.
+
+ The workaround promotes data cache clean instructions to
+ data cache clean-and-invalidate.
+ Please note that this option does not necessarily enable the
+ workaround, as it depends on the alternative framework, which will
+ only patch the kernel if an affected CPU is detected.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_819472
+ bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
+ default y
+ select ARM64_WORKAROUND_CLEAN_CACHE
+ help
+ This option adds an alternative code sequence to work around ARM
+ erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
+ present when it is connected to a coherent interconnect.
+
+ If the processor is executing a load and store exclusive sequence at
+ the same time as a processor in another cluster is executing a cache
+ maintenance operation to the same address, then this erratum might
+ cause data corruption.
+
+ The workaround promotes data cache clean instructions to
+ data cache clean-and-invalidate.
+ Please note that this does not necessarily enable the workaround,
+ as it depends on the alternative framework, which will only patch
+ the kernel if an affected CPU is detected.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_832075
+ bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
+ default y
+ help
+ This option adds an alternative code sequence to work around ARM
+ erratum 832075 on Cortex-A57 parts up to r1p2.
+
+ Affected Cortex-A57 parts might deadlock when exclusive load/store
+ instructions to Write-Back memory are mixed with Device loads.
+
+ The workaround is to promote device loads to use Load-Acquire
+ semantics.
+ Please note that this does not necessarily enable the workaround,
+ as it depends on the alternative framework, which will only patch
+ the kernel if an affected CPU is detected.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_834220
+ bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
+ depends on KVM
+ default y
+ help
+ This option adds an alternative code sequence to work around ARM
+ erratum 834220 on Cortex-A57 parts up to r1p2.
+
+ Affected Cortex-A57 parts might report a Stage 2 translation
+ fault as the result of a Stage 1 fault for load crossing a
+ page boundary when there is a permission or device memory
+ alignment fault at Stage 1 and a translation fault at Stage 2.
+
+ The workaround is to verify that the Stage 1 translation
+ doesn't generate a fault before handling the Stage 2 fault.
+ Please note that this does not necessarily enable the workaround,
+ as it depends on the alternative framework, which will only patch
+ the kernel if an affected CPU is detected.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_1742098
+ bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
+ depends on COMPAT
+ default y
+ help
+ This option removes the AES hwcap for aarch32 user-space to
+ workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
+
+ Affected parts may corrupt the AES state if an interrupt is
+ taken between a pair of AES instructions. These instructions
+ are only present if the cryptography extensions are present.
+ All software should have a fallback implementation for CPUs
+ that don't implement the cryptography extensions.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_845719
+ bool "Cortex-A53: 845719: a load might read incorrect data"
+ depends on COMPAT
+ default y
+ help
+ This option adds an alternative code sequence to work around ARM
+ erratum 845719 on Cortex-A53 parts up to r0p4.
+
+ When running a compat (AArch32) userspace on an affected Cortex-A53
+ part, a load at EL0 from a virtual address that matches the bottom 32
+ bits of the virtual address used by a recent load at (AArch64) EL1
+ might return incorrect data.
+
+ The workaround is to write the contextidr_el1 register on exception
+ return to a 32-bit task.
+ Please note that this does not necessarily enable the workaround,
+ as it depends on the alternative framework, which will only patch
+ the kernel if an affected CPU is detected.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_843419
+ bool "Cortex-A53: 843419: A load or store might access an incorrect address"
+ default y
+ help
+ This option links the kernel with '--fix-cortex-a53-843419' and
+ enables PLT support to replace certain ADRP instructions, which can
+ cause subsequent memory accesses to use an incorrect address on
+ Cortex-A53 parts up to r0p4.
+
+ If unsure, say Y.
+
+config ARM64_LD_HAS_FIX_ERRATUM_843419
+ def_bool $(ld-option,--fix-cortex-a53-843419)
+
+config ARM64_ERRATUM_1024718
+ bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
+ default y
+ help
+ This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
+
+ Affected Cortex-A55 cores (all revisions) could cause incorrect
+ update of the hardware dirty bit when the DBM/AP bits are updated
+ without a break-before-make. The workaround is to disable the usage
+ of hardware DBM locally on the affected cores. CPUs not affected by
+ this erratum will continue to use the feature.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_1418040
+ bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
+ default y
+ depends on COMPAT
+ help
+ This option adds a workaround for ARM Cortex-A76/Neoverse-N1
+ errata 1188873 and 1418040.
+
+ Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
+ cause register corruption when accessing the timer registers
+ from AArch32 userspace.
+
+ If unsure, say Y.
+
+config ARM64_WORKAROUND_SPECULATIVE_AT
+ bool
+
+config ARM64_ERRATUM_1165522
+ bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
+ default y
+ select ARM64_WORKAROUND_SPECULATIVE_AT
+ help
+ This option adds a workaround for ARM Cortex-A76 erratum 1165522.
+
+ Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
+ corrupted TLBs by speculating an AT instruction during a guest
+ context switch.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_1319367
+ bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
+ default y
+ select ARM64_WORKAROUND_SPECULATIVE_AT
+ help
+ This option adds work arounds for ARM Cortex-A57 erratum 1319537
+ and A72 erratum 1319367
+
+ Cortex-A57 and A72 cores could end-up with corrupted TLBs by
+ speculating an AT instruction during a guest context switch.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_1530923
+ bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
+ default y
+ select ARM64_WORKAROUND_SPECULATIVE_AT
+ help
+ This option adds a workaround for ARM Cortex-A55 erratum 1530923.
+
+ Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
+ corrupted TLBs by speculating an AT instruction during a guest
+ context switch.
+
+ If unsure, say Y.
+
+config ARM64_WORKAROUND_REPEAT_TLBI
+ bool
+
+config ARM64_ERRATUM_2441007
+ bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
+ default y
+ select ARM64_WORKAROUND_REPEAT_TLBI
+ help
+ This option adds a workaround for ARM Cortex-A55 erratum #2441007.
+
+ Under very rare circumstances, affected Cortex-A55 CPUs
+ may not handle a race between a break-before-make sequence on one
+ CPU, and another CPU accessing the same page. This could allow a
+ store to a page that has been unmapped.
+
+ Work around this by adding the affected CPUs to the list that needs
+ TLB sequences to be done twice.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_1286807
+ bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
+ default y
+ select ARM64_WORKAROUND_REPEAT_TLBI
+ help
+ This option adds a workaround for ARM Cortex-A76 erratum 1286807.
+
+ On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
+ address for a cacheable mapping of a location is being
+ accessed by a core while another core is remapping the virtual
+ address to a new physical page using the recommended
+ break-before-make sequence, then under very rare circumstances
+ TLBI+DSB completes before a read using the translation being
+ invalidated has been observed by other observers. The
+ workaround repeats the TLBI+DSB operation.
+
+config ARM64_ERRATUM_1463225
+ bool "Cortex-A76: Software Step might prevent interrupt recognition"
+ default y
+ help
+ This option adds a workaround for Arm Cortex-A76 erratum 1463225.
+
+ On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
+ of a system call instruction (SVC) can prevent recognition of
+ subsequent interrupts when software stepping is disabled in the
+ exception handler of the system call and either kernel debugging
+ is enabled or VHE is in use.
+
+ Work around the erratum by triggering a dummy step exception
+ when handling a system call from a task that is being stepped
+ in a VHE configuration of the kernel.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_1542419
+ bool "Neoverse-N1: workaround mis-ordering of instruction fetches"
+ default y
+ help
+ This option adds a workaround for ARM Neoverse-N1 erratum
+ 1542419.
+
+ Affected Neoverse-N1 cores could execute a stale instruction when
+ modified by another CPU. The workaround depends on a firmware
+ counterpart.
+
+ Workaround the issue by hiding the DIC feature from EL0. This
+ forces user-space to perform cache maintenance.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_1508412
+ bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
+ default y
+ help
+ This option adds a workaround for Arm Cortex-A77 erratum 1508412.
+
+ Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
+ of a store-exclusive or read of PAR_EL1 and a load with device or
+ non-cacheable memory attributes. The workaround depends on a firmware
+ counterpart.
+
+ KVM guests must also have the workaround implemented or they can
+ deadlock the system.
+
+ Work around the issue by inserting DMB SY barriers around PAR_EL1
+ register reads and warning KVM users. The DMB barrier is sufficient
+ to prevent a speculative PAR_EL1 read.
+
+ If unsure, say Y.
+
+config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
+ bool
+
+config ARM64_ERRATUM_2051678
+ bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
+ default y
+ help
+ This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
+ Affected Cortex-A510 might not respect the ordering rules for
+ hardware update of the page table's dirty bit. The workaround
+ is to not enable the feature on affected CPUs.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_2077057
+ bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
+ default y
+ help
+ This option adds the workaround for ARM Cortex-A510 erratum 2077057.
+ Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
+ expected, but a Pointer Authentication trap is taken instead. The
+ erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
+ EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
+
+ This can only happen when EL2 is stepping EL1.
+
+ When these conditions occur, the SPSR_EL2 value is unchanged from the
+ previous guest entry, and can be restored from the in-memory copy.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_2658417
+ bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
+ default y
+ help
+ This option adds the workaround for ARM Cortex-A510 erratum 2658417.
+ Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
+ BFMMLA or VMMLA instructions in rare circumstances when a pair of
+ A510 CPUs are using shared neon hardware. As the sharing is not
+ discoverable by the kernel, hide the BF16 HWCAP to indicate that
+ user-space should not be using these instructions.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_2119858
+ bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
+ default y
+ depends on CORESIGHT_TRBE
+ select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
+ help
+ This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
+
+ Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
+ data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
+ the event of a WRAP event.
+
+ Work around the issue by always making sure we move the TRBPTR_EL1 by
+ 256 bytes before enabling the buffer and filling the first 256 bytes of
+ the buffer with ETM ignore packets upon disabling.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_2139208
+ bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
+ default y
+ depends on CORESIGHT_TRBE
+ select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
+ help
+ This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
+
+ Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
+ data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
+ the event of a WRAP event.
+
+ Work around the issue by always making sure we move the TRBPTR_EL1 by
+ 256 bytes before enabling the buffer and filling the first 256 bytes of
+ the buffer with ETM ignore packets upon disabling.
+
+ If unsure, say Y.
+
+config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
+ bool
+
+config ARM64_ERRATUM_2054223
+ bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
+ default y
+ select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
+ help
+ Enable workaround for ARM Cortex-A710 erratum 2054223
+
+ Affected cores may fail to flush the trace data on a TSB instruction, when
+ the PE is in trace prohibited state. This will cause losing a few bytes
+ of the trace cached.
+
+ Workaround is to issue two TSB consecutively on affected cores.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_2067961
+ bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
+ default y
+ select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
+ help
+ Enable workaround for ARM Neoverse-N2 erratum 2067961
+
+ Affected cores may fail to flush the trace data on a TSB instruction, when
+ the PE is in trace prohibited state. This will cause losing a few bytes
+ of the trace cached.
+
+ Workaround is to issue two TSB consecutively on affected cores.
+
+ If unsure, say Y.
+
+config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
+ bool
+
+config ARM64_ERRATUM_2253138
+ bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
+ depends on CORESIGHT_TRBE
+ default y
+ select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
+ help
+ This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
+
+ Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
+ for TRBE. Under some conditions, the TRBE might generate a write to the next
+ virtually addressed page following the last page of the TRBE address space
+ (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
+
+ Work around this in the driver by always making sure that there is a
+ page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_2224489
+ bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
+ depends on CORESIGHT_TRBE
+ default y
+ select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
+ help
+ This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
+
+ Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
+ for TRBE. Under some conditions, the TRBE might generate a write to the next
+ virtually addressed page following the last page of the TRBE address space
+ (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
+
+ Work around this in the driver by always making sure that there is a
+ page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_2441009
+ bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
+ default y
+ select ARM64_WORKAROUND_REPEAT_TLBI
+ help
+ This option adds a workaround for ARM Cortex-A510 erratum #2441009.
+
+ Under very rare circumstances, affected Cortex-A510 CPUs
+ may not handle a race between a break-before-make sequence on one
+ CPU, and another CPU accessing the same page. This could allow a
+ store to a page that has been unmapped.
+
+ Work around this by adding the affected CPUs to the list that needs
+ TLB sequences to be done twice.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_2064142
+ bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
+ depends on CORESIGHT_TRBE
+ default y
+ help
+ This option adds the workaround for ARM Cortex-A510 erratum 2064142.
+
+ Affected Cortex-A510 core might fail to write into system registers after the
+ TRBE has been disabled. Under some conditions after the TRBE has been disabled
+ writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
+ and TRBTRG_EL1 will be ignored and will not be effected.
+
+ Work around this in the driver by executing TSB CSYNC and DSB after collection
+ is stopped and before performing a system register write to one of the affected
+ registers.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_2038923
+ bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
+ depends on CORESIGHT_TRBE
+ default y
+ help
+ This option adds the workaround for ARM Cortex-A510 erratum 2038923.
+
+ Affected Cortex-A510 core might cause an inconsistent view on whether trace is
+ prohibited within the CPU. As a result, the trace buffer or trace buffer state
+ might be corrupted. This happens after TRBE buffer has been enabled by setting
+ TRBLIMITR_EL1.E, followed by just a single context synchronization event before
+ execution changes from a context, in which trace is prohibited to one where it
+ isn't, or vice versa. In these mentioned conditions, the view of whether trace
+ is prohibited is inconsistent between parts of the CPU, and the trace buffer or
+ the trace buffer state might be corrupted.
+
+ Work around this in the driver by preventing an inconsistent view of whether the
+ trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
+ change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
+ two ISB instructions if no ERET is to take place.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_1902691
+ bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
+ depends on CORESIGHT_TRBE
+ default y
+ help
+ This option adds the workaround for ARM Cortex-A510 erratum 1902691.
+
+ Affected Cortex-A510 core might cause trace data corruption, when being written
+ into the memory. Effectively TRBE is broken and hence cannot be used to capture
+ trace data.
+
+ Work around this problem in the driver by just preventing TRBE initialization on
+ affected cpus. The firmware must have disabled the access to TRBE for the kernel
+ on such implementations. This will cover the kernel for any firmware that doesn't
+ do this already.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_2457168
+ bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
+ depends on ARM64_AMU_EXTN
+ default y
+ help
+ This option adds the workaround for ARM Cortex-A510 erratum 2457168.
+
+ The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
+ as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
+ incorrectly giving a significantly higher output value.
+
+ Work around this problem by returning 0 when reading the affected counter in
+ key locations that results in disabling all users of this counter. This effect
+ is the same to firmware disabling affected counters.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_2645198
+ bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
+ default y
+ help
+ This option adds the workaround for ARM Cortex-A715 erratum 2645198.
+
+ If a Cortex-A715 cpu sees a page mapping permissions change from executable
+ to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
+ next instruction abort caused by permission fault.
+
+ Only user-space does executable to non-executable permission transition via
+ mprotect() system call. Workaround the problem by doing a break-before-make
+ TLB invalidation, for all changes to executable user space mappings.
+
+ If unsure, say Y.
+
+config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
+ bool
+
+config ARM64_ERRATUM_2966298
+ bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load"
+ select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
+ default y
+ help
+ This option adds the workaround for ARM Cortex-A520 erratum 2966298.
+
+ On an affected Cortex-A520 core, a speculatively executed unprivileged
+ load might leak data from a privileged level via a cache side channel.
+
+ Work around this problem by executing a TLBI before returning to EL0.
+
+ If unsure, say Y.
+
+config ARM64_ERRATUM_3117295
+ bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load"
+ select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
+ default y
+ help
+ This option adds the workaround for ARM Cortex-A510 erratum 3117295.
+
+ On an affected Cortex-A510 core, a speculatively executed unprivileged
+ load might leak data from a privileged level via a cache side channel.
+
+ Work around this problem by executing a TLBI before returning to EL0.
+
+ If unsure, say Y.
+
+config CAVIUM_ERRATUM_22375
+ bool "Cavium erratum 22375, 24313"
+ default y
+ help
+ Enable workaround for errata 22375 and 24313.
+
+ This implements two gicv3-its errata workarounds for ThunderX. Both
+ with a small impact affecting only ITS table allocation.
+
+ erratum 22375: only alloc 8MB table size
+ erratum 24313: ignore memory access type
+
+ The fixes are in ITS initialization and basically ignore memory access
+ type and table size provided by the TYPER and BASER registers.
+
+ If unsure, say Y.
+
+config CAVIUM_ERRATUM_23144
+ bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
+ depends on NUMA
+ default y
+ help
+ ITS SYNC command hang for cross node io and collections/cpu mapping.
+
+ If unsure, say Y.
+
+config CAVIUM_ERRATUM_23154
+ bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
+ default y
+ help
+ The ThunderX GICv3 implementation requires a modified version for
+ reading the IAR status to ensure data synchronization
+ (access to icc_iar1_el1 is not sync'ed before and after).
+
+ It also suffers from erratum 38545 (also present on Marvell's
+ OcteonTX and OcteonTX2), resulting in deactivated interrupts being
+ spuriously presented to the CPU interface.
+
+ If unsure, say Y.
+
+config CAVIUM_ERRATUM_27456
+ bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
+ default y
+ help
+ On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
+ instructions may cause the icache to become corrupted if it
+ contains data for a non-current ASID. The fix is to
+ invalidate the icache when changing the mm context.
+
+ If unsure, say Y.
+
+config CAVIUM_ERRATUM_30115
+ bool "Cavium erratum 30115: Guest may disable interrupts in host"
+ default y
+ help
+ On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
+ 1.2, and T83 Pass 1.0, KVM guest execution may disable
+ interrupts in host. Trapping both GICv3 group-0 and group-1
+ accesses sidesteps the issue.
+
+ If unsure, say Y.
+
+config CAVIUM_TX2_ERRATUM_219
+ bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
+ default y
+ help
+ On Cavium ThunderX2, a load, store or prefetch instruction between a
+ TTBR update and the corresponding context synchronizing operation can
+ cause a spurious Data Abort to be delivered to any hardware thread in
+ the CPU core.
+
+ Work around the issue by avoiding the problematic code sequence and
+ trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
+ trap handler performs the corresponding register access, skips the
+ instruction and ensures context synchronization by virtue of the
+ exception return.
+
+ If unsure, say Y.
+
+config FUJITSU_ERRATUM_010001
+ bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
+ default y
+ help
+ This option adds a workaround for Fujitsu-A64FX erratum E#010001.
+ On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
+ accesses may cause undefined fault (Data abort, DFSC=0b111111).
+ This fault occurs under a specific hardware condition when a
+ load/store instruction performs an address translation using:
+ case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1.
+ case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1.
+ case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1.
+ case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1.
+
+ The workaround is to ensure these bits are clear in TCR_ELx.
+ The workaround only affects the Fujitsu-A64FX.
+
+ If unsure, say Y.
+
+config HISILICON_ERRATUM_161600802
+ bool "Hip07 161600802: Erroneous redistributor VLPI base"
+ default y
+ help
+ The HiSilicon Hip07 SoC uses the wrong redistributor base
+ when issued ITS commands such as VMOVP and VMAPP, and requires
+ a 128kB offset to be applied to the target address in this commands.
+
+ If unsure, say Y.
+
+config QCOM_FALKOR_ERRATUM_1003
+ bool "Falkor E1003: Incorrect translation due to ASID change"
+ default y
+ help
+ On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
+ and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
+ in TTBR1_EL1, this situation only occurs in the entry trampoline and
+ then only for entries in the walk cache, since the leaf translation
+ is unchanged. Work around the erratum by invalidating the walk cache
+ entries for the trampoline before entering the kernel proper.
+
+config QCOM_FALKOR_ERRATUM_1009
+ bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
+ default y
+ select ARM64_WORKAROUND_REPEAT_TLBI
+ help
+ On Falkor v1, the CPU may prematurely complete a DSB following a
+ TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
+ one more time to fix the issue.
+
+ If unsure, say Y.
+
+config QCOM_QDF2400_ERRATUM_0065
+ bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
+ default y
+ help
+ On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
+ ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
+ been indicated as 16Bytes (0xf), not 8Bytes (0x7).
+
+ If unsure, say Y.
+
+config QCOM_FALKOR_ERRATUM_E1041
+ bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
+ default y
+ help
+ Falkor CPU may speculatively fetch instructions from an improper
+ memory location when MMU translation is changed from SCTLR_ELn[M]=1
+ to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
+
+ If unsure, say Y.
+
+config NVIDIA_CARMEL_CNP_ERRATUM
+ bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
+ default y
+ help
+ If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
+ invalidate shared TLB entries installed by a different core, as it would
+ on standard ARM cores.
+
+ If unsure, say Y.
+
+config ROCKCHIP_ERRATUM_3588001
+ bool "Rockchip 3588001: GIC600 can not support shareability attributes"
+ default y
+ help
+ The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
+ This means, that its sharability feature may not be used, even though it
+ is supported by the IP itself.
+
+ If unsure, say Y.
+
+config SOCIONEXT_SYNQUACER_PREITS
+ bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
+ default y
+ help
+ Socionext Synquacer SoCs implement a separate h/w block to generate
+ MSI doorbell writes with non-zero values for the device ID.
+
+ If unsure, say Y.
+
+endmenu # "ARM errata workarounds via the alternatives framework"
+
+choice
+ prompt "Page size"
+ default ARM64_4K_PAGES
+ help
+ Page size (translation granule) configuration.
+
+config ARM64_4K_PAGES
+ bool "4KB"
+ help
+ This feature enables 4KB pages support.
+
+config ARM64_16K_PAGES
+ bool "16KB"
+ help
+ The system will use 16KB pages support. AArch32 emulation
+ requires applications compiled with 16K (or a multiple of 16K)
+ aligned segments.
+
+config ARM64_64K_PAGES
+ bool "64KB"
+ help
+ This feature enables 64KB pages support (4KB by default)
+ allowing only two levels of page tables and faster TLB
+ look-up. AArch32 emulation requires applications compiled
+ with 64K aligned segments.
+
+endchoice
+
+choice
+ prompt "Virtual address space size"
+ default ARM64_VA_BITS_39 if ARM64_4K_PAGES
+ default ARM64_VA_BITS_47 if ARM64_16K_PAGES
+ default ARM64_VA_BITS_42 if ARM64_64K_PAGES
+ help
+ Allows choosing one of multiple possible virtual address
+ 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" if EXPERT
+ depends on ARM64_16K_PAGES
+
+config ARM64_VA_BITS_39
+ bool "39-bit"
+ depends on ARM64_4K_PAGES
+
+config ARM64_VA_BITS_42
+ bool "42-bit"
+ depends on ARM64_64K_PAGES
+
+config ARM64_VA_BITS_47
+ bool "47-bit"
+ depends on ARM64_16K_PAGES
+
+config ARM64_VA_BITS_48
+ bool "48-bit"
+
+config ARM64_VA_BITS_52
+ bool "52-bit"
+ depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
+ help
+ Enable 52-bit virtual addressing for userspace when explicitly
+ requested via a hint to mmap(). The kernel will also use 52-bit
+ virtual addresses for its own mappings (provided HW support for
+ this feature is available, otherwise it reverts to 48-bit).
+
+ NOTE: Enabling 52-bit virtual addressing in conjunction with
+ ARMv8.3 Pointer Authentication will result in the PAC being
+ reduced from 7 bits to 3 bits, which may have a significant
+ impact on its susceptibility to brute-force attacks.
+
+ If unsure, select 48-bit virtual addressing instead.
+
+endchoice
+
+config ARM64_FORCE_52BIT
+ bool "Force 52-bit virtual addresses for userspace"
+ depends on ARM64_VA_BITS_52 && EXPERT
+ help
+ For systems with 52-bit userspace VAs enabled, the kernel will attempt
+ to maintain compatibility with older software by providing 48-bit VAs
+ unless a hint is supplied to mmap.
+
+ This configuration option disables the 48-bit compatibility logic, and
+ forces all userspace addresses to be 52-bit on HW that supports it. One
+ should only enable this configuration option for stress testing userspace
+ memory management code. If unsure say N here.
+
+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
+ default 48 if ARM64_VA_BITS_48
+ default 52 if ARM64_VA_BITS_52
+
+choice
+ prompt "Physical address space size"
+ default ARM64_PA_BITS_48
+ help
+ Choose the maximum physical address range that the kernel will
+ support.
+
+config ARM64_PA_BITS_48
+ bool "48-bit"
+
+config ARM64_PA_BITS_52
+ bool "52-bit (ARMv8.2)"
+ depends on ARM64_64K_PAGES
+ depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
+ help
+ Enable support for a 52-bit physical address space, introduced as
+ part of the ARMv8.2-LPA extension.
+
+ With this enabled, the kernel will also continue to work on CPUs that
+ do not support ARMv8.2-LPA, but with some added memory overhead (and
+ minor performance overhead).
+
+endchoice
+
+config ARM64_PA_BITS
+ int
+ default 48 if ARM64_PA_BITS_48
+ default 52 if ARM64_PA_BITS_52
+
+choice
+ prompt "Endianness"
+ default CPU_LITTLE_ENDIAN
+ help
+ Select the endianness of data accesses performed by the CPU. Userspace
+ applications will need to be compiled and linked for the endianness
+ that is selected here.
+
+config CPU_BIG_ENDIAN
+ bool "Build big-endian kernel"
+ depends on !LD_IS_LLD || LLD_VERSION >= 130000
+ # https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c
+ depends on AS_IS_GNU || AS_VERSION >= 150000
+ help
+ Say Y if you plan on running a kernel with a big-endian userspace.
+
+config CPU_LITTLE_ENDIAN
+ bool "Build little-endian kernel"
+ help
+ Say Y if you plan on running a kernel with a little-endian userspace.
+ This is usually the case for distributions targeting arm64.
+
+endchoice
+
+config SCHED_MC
+ bool "Multi-core scheduler support"
+ help
+ Multi-core scheduler support improves the CPU scheduler's decision
+ making when dealing with multi-core CPU chips at a cost of slightly
+ increased overhead in some places. If unsure say N here.
+
+config SCHED_CLUSTER
+ bool "Cluster scheduler support"
+ help
+ Cluster scheduler support improves the CPU scheduler's decision
+ making when dealing with machines that have clusters of CPUs.
+ Cluster usually means a couple of CPUs which are placed closely
+ by sharing mid-level caches, last-level cache tags or internal
+ busses.
+
+config SCHED_SMT
+ bool "SMT scheduler support"
+ help
+ Improves the CPU scheduler's decision making when dealing with
+ MultiThreading at a cost of slightly increased overhead in some
+ places. If unsure say N here.
+
+config NR_CPUS
+ int "Maximum number of CPUs (2-4096)"
+ range 2 4096
+ default "256"
+
+config HOTPLUG_CPU
+ bool "Support for hot-pluggable CPUs"
+ select GENERIC_IRQ_MIGRATION
+ help
+ Say Y here to experiment with turning CPUs off and on. CPUs
+ can be controlled through /sys/devices/system/cpu.
+
+# Common NUMA Features
+config NUMA
+ bool "NUMA Memory Allocation and Scheduler Support"
+ select GENERIC_ARCH_NUMA
+ select ACPI_NUMA if ACPI
+ select OF_NUMA
+ select HAVE_SETUP_PER_CPU_AREA
+ select NEED_PER_CPU_EMBED_FIRST_CHUNK
+ select NEED_PER_CPU_PAGE_FIRST_CHUNK
+ select USE_PERCPU_NUMA_NODE_ID
+ help
+ Enable NUMA (Non-Uniform Memory Access) support.
+
+ The kernel will try to allocate memory used by a CPU on the
+ local memory of the CPU and add some more
+ NUMA awareness to the kernel.
+
+config NODES_SHIFT
+ int "Maximum NUMA Nodes (as a power of 2)"
+ range 1 10
+ default "4"
+ depends on NUMA
+ help
+ Specify the maximum number of NUMA Nodes available on the target
+ system. Increases memory reserved to accommodate various tables.
+
+source "kernel/Kconfig.hz"
+
+config ARCH_SPARSEMEM_ENABLE
+ def_bool y
+ select SPARSEMEM_VMEMMAP_ENABLE
+ select SPARSEMEM_VMEMMAP
+
+config HW_PERF_EVENTS
+ def_bool y
+ depends on ARM_PMU
+
+# Supported by clang >= 7.0 or GCC >= 12.0.0
+config CC_HAVE_SHADOW_CALL_STACK
+ def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
+
+config PARAVIRT
+ bool "Enable paravirtualization code"
+ help
+ This changes the kernel so it can modify itself when it is run
+ under a hypervisor, potentially improving performance significantly
+ over full virtualization.
+
+config PARAVIRT_TIME_ACCOUNTING
+ bool "Paravirtual steal time accounting"
+ select PARAVIRT
+ help
+ Select this option to enable fine granularity task steal time
+ accounting. Time spent executing other tasks in parallel with
+ the current vCPU is discounted from the vCPU power. To account for
+ that, there can be a small performance impact.
+
+ If in doubt, say N here.
+
+config ARCH_SUPPORTS_KEXEC
+ def_bool PM_SLEEP_SMP
+
+config ARCH_SUPPORTS_KEXEC_FILE
+ def_bool y
+
+config ARCH_SELECTS_KEXEC_FILE
+ def_bool y
+ depends on KEXEC_FILE
+ select HAVE_IMA_KEXEC if IMA
+
+config ARCH_SUPPORTS_KEXEC_SIG
+ def_bool y
+
+config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
+ def_bool y
+
+config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
+ def_bool y
+
+config ARCH_SUPPORTS_CRASH_DUMP
+ def_bool y
+
+config TRANS_TABLE
+ def_bool y
+ depends on HIBERNATION || KEXEC_CORE
+
+config XEN_DOM0
+ def_bool y
+ depends on XEN
+
+config XEN
+ bool "Xen guest support on ARM64"
+ depends on ARM64 && OF
+ select SWIOTLB_XEN
+ select PARAVIRT
+ help
+ Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
+
+# include/linux/mmzone.h requires the following to be true:
+#
+# MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
+#
+# so the maximum value of MAX_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
+#
+# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_ORDER | default MAX_ORDER |
+# ----+-------------------+--------------+-----------------+--------------------+
+# 4K | 27 | 12 | 15 | 10 |
+# 16K | 27 | 14 | 13 | 11 |
+# 64K | 29 | 16 | 13 | 13 |
+config ARCH_FORCE_MAX_ORDER
+ int
+ default "13" if ARM64_64K_PAGES
+ default "11" if ARM64_16K_PAGES
+ default "10"
+ help
+ The kernel page allocator limits the size of maximal physically
+ contiguous allocations. The limit is called MAX_ORDER and it
+ defines the maximal power of two of number of pages that can be
+ allocated as a single contiguous block. This option allows
+ overriding the default setting when ability to allocate very
+ large blocks of physically contiguous memory is required.
+
+ The maximal size of allocation cannot exceed the size of the
+ section, so the value of MAX_ORDER should satisfy
+
+ MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
+
+ Don't change if unsure.
+
+config UNMAP_KERNEL_AT_EL0
+ bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
+ default y
+ help
+ Speculation attacks against some high-performance processors can
+ be used to bypass MMU permission checks and leak kernel data to
+ userspace. This can be defended against by unmapping the kernel
+ when running in userspace, mapping it back in on exception entry
+ via a trampoline page in the vector table.
+
+ If unsure, say Y.
+
+config MITIGATE_SPECTRE_BRANCH_HISTORY
+ bool "Mitigate Spectre style attacks against branch history" if EXPERT
+ default y
+ help
+ Speculation attacks against some high-performance processors can
+ make use of branch history to influence future speculation.
+ When taking an exception from user-space, a sequence of branches
+ or a firmware call overwrites the branch history.
+
+config RODATA_FULL_DEFAULT_ENABLED
+ bool "Apply r/o permissions of VM areas also to their linear aliases"
+ default y
+ help
+ Apply read-only attributes of VM areas to the linear alias of
+ the backing pages as well. This prevents code or read-only data
+ from being modified (inadvertently or intentionally) via another
+ mapping of the same memory page. This additional enhancement can
+ be turned off at runtime by passing rodata=[off|on] (and turned on
+ with rodata=full if this option is set to 'n')
+
+ This requires the linear region to be mapped down to pages,
+ which may adversely affect performance in some cases.
+
+config ARM64_SW_TTBR0_PAN
+ bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
+ help
+ Enabling this option prevents the kernel from accessing
+ user-space memory directly by pointing TTBR0_EL1 to a reserved
+ zeroed area and reserved ASID. The user access routines
+ restore the valid TTBR0_EL1 temporarily.
+
+config ARM64_TAGGED_ADDR_ABI
+ bool "Enable the tagged user addresses syscall ABI"
+ default y
+ help
+ When this option is enabled, user applications can opt in to a
+ relaxed ABI via prctl() allowing tagged addresses to be passed
+ to system calls as pointer arguments. For details, see
+ Documentation/arch/arm64/tagged-address-abi.rst.
+
+menuconfig COMPAT
+ bool "Kernel support for 32-bit EL0"
+ depends on ARM64_4K_PAGES || EXPERT
+ select HAVE_UID16
+ select OLD_SIGSUSPEND3
+ select COMPAT_OLD_SIGACTION
+ help
+ This option enables support for a 32-bit EL0 running under a 64-bit
+ kernel at EL1. AArch32-specific components such as system calls,
+ the user helper functions, VFP support and the ptrace interface are
+ handled appropriately by the kernel.
+
+ If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
+ that you will only be able to execute AArch32 binaries that were compiled
+ with page size aligned segments.
+
+ If you want to execute 32-bit userspace applications, say Y.
+
+if COMPAT
+
+config KUSER_HELPERS
+ bool "Enable kuser helpers page for 32-bit applications"
+ default y
+ help
+ Warning: disabling this option may break 32-bit user programs.
+
+ Provide kuser helpers to compat tasks. The kernel provides
+ helper code to userspace in read only form at a fixed location
+ to allow userspace to be independent of the CPU type fitted to
+ the system. This permits binaries to be run on ARMv4 through
+ to ARMv8 without modification.
+
+ See Documentation/arch/arm/kernel_user_helpers.rst for details.
+
+ However, the fixed address nature of these helpers can be used
+ by ROP (return orientated programming) authors when creating
+ exploits.
+
+ If all of the binaries and libraries which run on your platform
+ are built specifically for your platform, and make no use of
+ these helpers, then you can turn this option off to hinder
+ such exploits. However, in that case, if a binary or library
+ relying on those helpers is run, it will not function correctly.
+
+ Say N here only if you are absolutely certain that you do not
+ need these helpers; otherwise, the safe option is to say Y.
+
+config COMPAT_VDSO
+ bool "Enable vDSO for 32-bit applications"
+ depends on !CPU_BIG_ENDIAN
+ depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
+ select GENERIC_COMPAT_VDSO
+ default y
+ help
+ Place in the process address space of 32-bit applications an
+ ELF shared object providing fast implementations of gettimeofday
+ and clock_gettime.
+
+ You must have a 32-bit build of glibc 2.22 or later for programs
+ to seamlessly take advantage of this.
+
+config THUMB2_COMPAT_VDSO
+ bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
+ depends on COMPAT_VDSO
+ default y
+ help
+ Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
+ otherwise with '-marm'.
+
+config COMPAT_ALIGNMENT_FIXUPS
+ bool "Fix up misaligned multi-word loads and stores in user space"
+
+menuconfig ARMV8_DEPRECATED
+ bool "Emulate deprecated/obsolete ARMv8 instructions"
+ depends on SYSCTL
+ help
+ Legacy software support may require certain instructions
+ that have been deprecated or obsoleted in the architecture.
+
+ Enable this config to enable selective emulation of these
+ features.
+
+ If unsure, say Y
+
+if ARMV8_DEPRECATED
+
+config SWP_EMULATION
+ bool "Emulate SWP/SWPB instructions"
+ help
+ ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
+ they are always undefined. Say Y here to enable software
+ emulation of these instructions for userspace using LDXR/STXR.
+ This feature can be controlled at runtime with the abi.swp
+ sysctl which is disabled by default.
+
+ In some older versions of glibc [<=2.8] SWP is used during futex
+ trylock() operations with the assumption that the code will not
+ be preempted. This invalid assumption may be more likely to fail
+ with SWP emulation enabled, leading to deadlock of the user
+ application.
+
+ NOTE: when accessing uncached shared regions, LDXR/STXR rely
+ on an external transaction monitoring block called a global
+ monitor to maintain update atomicity. If your system does not
+ implement a global monitor, this option can cause programs that
+ perform SWP operations to uncached memory to deadlock.
+
+ If unsure, say Y
+
+config CP15_BARRIER_EMULATION
+ bool "Emulate CP15 Barrier instructions"
+ help
+ The CP15 barrier instructions - CP15ISB, CP15DSB, and
+ CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
+ strongly recommended to use the ISB, DSB, and DMB
+ instructions instead.
+
+ Say Y here to enable software emulation of these
+ instructions for AArch32 userspace code. When this option is
+ enabled, CP15 barrier usage is traced which can help
+ identify software that needs updating. This feature can be
+ controlled at runtime with the abi.cp15_barrier sysctl.
+
+ If unsure, say Y
+
+config SETEND_EMULATION
+ bool "Emulate SETEND instruction"
+ help
+ The SETEND instruction alters the data-endianness of the
+ AArch32 EL0, and is deprecated in ARMv8.
+
+ Say Y here to enable software emulation of the instruction
+ for AArch32 userspace code. This feature can be controlled
+ at runtime with the abi.setend sysctl.
+
+ Note: All the cpus on the system must have mixed endian support at EL0
+ for this feature to be enabled. If a new CPU - which doesn't support mixed
+ endian - is hotplugged in after this feature has been enabled, there could
+ be unexpected results in the applications.
+
+ If unsure, say Y
+endif # ARMV8_DEPRECATED
+
+endif # COMPAT
+
+menu "ARMv8.1 architectural features"
+
+config ARM64_HW_AFDBM
+ bool "Support for hardware updates of the Access and Dirty page flags"
+ default y
+ help
+ The ARMv8.1 architecture extensions introduce support for
+ hardware updates of the access and dirty information in page
+ table entries. When enabled in TCR_EL1 (HA and HD bits) on
+ capable processors, accesses to pages with PTE_AF cleared will
+ set this bit instead of raising an access flag fault.
+ Similarly, writes to read-only pages with the DBM bit set will
+ clear the read-only bit (AP[2]) instead of raising a
+ permission fault.
+
+ Kernels built with this configuration option enabled continue
+ to work on pre-ARMv8.1 hardware and the performance impact is
+ minimal. If unsure, say Y.
+
+config ARM64_PAN
+ bool "Enable support for Privileged Access Never (PAN)"
+ default y
+ help
+ Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
+ prevents the kernel or hypervisor from accessing user-space (EL0)
+ memory directly.
+
+ Choosing this option will cause any unprotected (not using
+ copy_to_user et al) memory access to fail with a permission fault.
+
+ The feature is detected at runtime, and will remain as a 'nop'
+ instruction if the cpu does not implement the feature.
+
+config AS_HAS_LSE_ATOMICS
+ def_bool $(as-instr,.arch_extension lse)
+
+config ARM64_LSE_ATOMICS
+ bool
+ default ARM64_USE_LSE_ATOMICS
+ depends on AS_HAS_LSE_ATOMICS
+
+config ARM64_USE_LSE_ATOMICS
+ bool "Atomic instructions"
+ default y
+ help
+ As part of the Large System Extensions, ARMv8.1 introduces new
+ atomic instructions that are designed specifically to scale in
+ very large systems.
+
+ Say Y here to make use of these instructions for the in-kernel
+ atomic routines. This incurs a small overhead on CPUs that do
+ not support these instructions and requires the kernel to be
+ built with binutils >= 2.25 in order for the new instructions
+ to be used.
+
+endmenu # "ARMv8.1 architectural features"
+
+menu "ARMv8.2 architectural features"
+
+config AS_HAS_ARMV8_2
+ def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a)
+
+config AS_HAS_SHA3
+ def_bool $(as-instr,.arch armv8.2-a+sha3)
+
+config ARM64_PMEM
+ bool "Enable support for persistent memory"
+ select ARCH_HAS_PMEM_API
+ select ARCH_HAS_UACCESS_FLUSHCACHE
+ help
+ Say Y to enable support for the persistent memory API based on the
+ ARMv8.2 DCPoP feature.
+
+ The feature is detected at runtime, and the kernel will use DC CVAC
+ operations if DC CVAP is not supported (following the behaviour of
+ DC CVAP itself if the system does not define a point of persistence).
+
+config ARM64_RAS_EXTN
+ bool "Enable support for RAS CPU Extensions"
+ default y
+ help
+ CPUs that support the Reliability, Availability and Serviceability
+ (RAS) Extensions, part of ARMv8.2 are able to track faults and
+ errors, classify them and report them to software.
+
+ On CPUs with these extensions system software can use additional
+ barriers to determine if faults are pending and read the
+ classification from a new set of registers.
+
+ Selecting this feature will allow the kernel to use these barriers
+ and access the new registers if the system supports the extension.
+ Platform RAS features may additionally depend on firmware support.
+
+config ARM64_CNP
+ bool "Enable support for Common Not Private (CNP) translations"
+ default y
+ depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
+ help
+ Common Not Private (CNP) allows translation table entries to
+ be shared between different PEs in the same inner shareable
+ domain, so the hardware can use this fact to optimise the
+ caching of such entries in the TLB.
+
+ Selecting this option allows the CNP feature to be detected
+ at runtime, and does not affect PEs that do not implement
+ this feature.
+
+endmenu # "ARMv8.2 architectural features"
+
+menu "ARMv8.3 architectural features"
+
+config ARM64_PTR_AUTH
+ bool "Enable support for pointer authentication"
+ default y
+ help
+ Pointer authentication (part of the ARMv8.3 Extensions) provides
+ instructions for signing and authenticating pointers against secret
+ keys, which can be used to mitigate Return Oriented Programming (ROP)
+ and other attacks.
+
+ This option enables these instructions at EL0 (i.e. for userspace).
+ Choosing this option will cause the kernel to initialise secret keys
+ for each process at exec() time, with these keys being
+ context-switched along with the process.
+
+ The feature is detected at runtime. If the feature is not present in
+ hardware it will not be advertised to userspace/KVM guest nor will it
+ be enabled.
+
+ If the feature is present on the boot CPU but not on a late CPU, then
+ the late CPU will be parked. Also, if the boot CPU does not have
+ address auth and the late CPU has then the late CPU will still boot
+ but with the feature disabled. On such a system, this option should
+ not be selected.
+
+config ARM64_PTR_AUTH_KERNEL
+ bool "Use pointer authentication for kernel"
+ default y
+ depends on ARM64_PTR_AUTH
+ depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3
+ # Modern compilers insert a .note.gnu.property section note for PAC
+ # which is only understood by binutils starting with version 2.33.1.
+ depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
+ depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
+ depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
+ help
+ If the compiler supports the -mbranch-protection or
+ -msign-return-address flag (e.g. GCC 7 or later), then this option
+ will cause the kernel itself to be compiled with return address
+ protection. In this case, and if the target hardware is known to
+ support pointer authentication, then CONFIG_STACKPROTECTOR can be
+ disabled with minimal loss of protection.
+
+ This feature works with FUNCTION_GRAPH_TRACER option only if
+ DYNAMIC_FTRACE_WITH_ARGS is enabled.
+
+config CC_HAS_BRANCH_PROT_PAC_RET
+ # GCC 9 or later, clang 8 or later
+ def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
+
+config CC_HAS_SIGN_RETURN_ADDRESS
+ # GCC 7, 8
+ def_bool $(cc-option,-msign-return-address=all)
+
+config AS_HAS_ARMV8_3
+ def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
+
+config AS_HAS_CFI_NEGATE_RA_STATE
+ def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
+
+config AS_HAS_LDAPR
+ def_bool $(as-instr,.arch_extension rcpc)
+
+endmenu # "ARMv8.3 architectural features"
+
+menu "ARMv8.4 architectural features"
+
+config ARM64_AMU_EXTN
+ bool "Enable support for the Activity Monitors Unit CPU extension"
+ default y
+ help
+ The activity monitors extension is an optional extension introduced
+ by the ARMv8.4 CPU architecture. This enables support for version 1
+ of the activity monitors architecture, AMUv1.
+
+ To enable the use of this extension on CPUs that implement it, say Y.
+
+ Note that for architectural reasons, firmware _must_ implement AMU
+ support when running on CPUs that present the activity monitors
+ extension. The required support is present in:
+ * Version 1.5 and later of the ARM Trusted Firmware
+
+ For kernels that have this configuration enabled but boot with broken
+ firmware, you may need to say N here until the firmware is fixed.
+ Otherwise you may experience firmware panics or lockups when
+ accessing the counter registers. Even if you are not observing these
+ symptoms, the values returned by the register reads might not
+ correctly reflect reality. Most commonly, the value read will be 0,
+ indicating that the counter is not enabled.
+
+config AS_HAS_ARMV8_4
+ def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
+
+config ARM64_TLB_RANGE
+ bool "Enable support for tlbi range feature"
+ default y
+ depends on AS_HAS_ARMV8_4
+ help
+ ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
+ range of input addresses.
+
+ The feature introduces new assembly instructions, and they were
+ support when binutils >= 2.30.
+
+endmenu # "ARMv8.4 architectural features"
+
+menu "ARMv8.5 architectural features"
+
+config AS_HAS_ARMV8_5
+ def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
+
+config ARM64_BTI
+ bool "Branch Target Identification support"
+ default y
+ help
+ Branch Target Identification (part of the ARMv8.5 Extensions)
+ provides a mechanism to limit the set of locations to which computed
+ branch instructions such as BR or BLR can jump.
+
+ To make use of BTI on CPUs that support it, say Y.
+
+ BTI is intended to provide complementary protection to other control
+ flow integrity protection mechanisms, such as the Pointer
+ authentication mechanism provided as part of the ARMv8.3 Extensions.
+ For this reason, it does not make sense to enable this option without
+ also enabling support for pointer authentication. Thus, when
+ enabling this option you should also select ARM64_PTR_AUTH=y.
+
+ Userspace binaries must also be specifically compiled to make use of
+ this mechanism. If you say N here or the hardware does not support
+ BTI, such binaries can still run, but you get no additional
+ enforcement of branch destinations.
+
+config ARM64_BTI_KERNEL
+ bool "Use Branch Target Identification for kernel"
+ default y
+ depends on ARM64_BTI
+ depends on ARM64_PTR_AUTH_KERNEL
+ depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
+ # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
+ depends on !CC_IS_GCC || GCC_VERSION >= 100100
+ # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
+ depends on !CC_IS_GCC
+ # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9
+ depends on !CC_IS_CLANG || CLANG_VERSION >= 120000
+ depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
+ help
+ Build the kernel with Branch Target Identification annotations
+ and enable enforcement of this for kernel code. When this option
+ is enabled and the system supports BTI all kernel code including
+ modular code must have BTI enabled.
+
+config CC_HAS_BRANCH_PROT_PAC_RET_BTI
+ # GCC 9 or later, clang 8 or later
+ def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
+
+config ARM64_E0PD
+ bool "Enable support for E0PD"
+ default y
+ help
+ E0PD (part of the ARMv8.5 extensions) allows us to ensure
+ that EL0 accesses made via TTBR1 always fault in constant time,
+ providing similar benefits to KASLR as those provided by KPTI, but
+ with lower overhead and without disrupting legitimate access to
+ kernel memory such as SPE.
+
+ This option enables E0PD for TTBR1 where available.
+
+config ARM64_AS_HAS_MTE
+ # Initial support for MTE went in binutils 2.32.0, checked with
+ # ".arch armv8.5-a+memtag" below. However, this was incomplete
+ # as a late addition to the final architecture spec (LDGM/STGM)
+ # is only supported in the newer 2.32.x and 2.33 binutils
+ # versions, hence the extra "stgm" instruction check below.
+ def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
+
+config ARM64_MTE
+ bool "Memory Tagging Extension support"
+ default y
+ depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
+ depends on AS_HAS_ARMV8_5
+ depends on AS_HAS_LSE_ATOMICS
+ # Required for tag checking in the uaccess routines
+ depends on ARM64_PAN
+ select ARCH_HAS_SUBPAGE_FAULTS
+ select ARCH_USES_HIGH_VMA_FLAGS
+ select ARCH_USES_PG_ARCH_X
+ help
+ Memory Tagging (part of the ARMv8.5 Extensions) provides
+ architectural support for run-time, always-on detection of
+ various classes of memory error to aid with software debugging
+ to eliminate vulnerabilities arising from memory-unsafe
+ languages.
+
+ This option enables the support for the Memory Tagging
+ Extension at EL0 (i.e. for userspace).
+
+ Selecting this option allows the feature to be detected at
+ runtime. Any secondary CPU not implementing this feature will
+ not be allowed a late bring-up.
+
+ Userspace binaries that want to use this feature must
+ explicitly opt in. The mechanism for the userspace is
+ described in:
+
+ Documentation/arch/arm64/memory-tagging-extension.rst.
+
+endmenu # "ARMv8.5 architectural features"
+
+menu "ARMv8.7 architectural features"
+
+config ARM64_EPAN
+ bool "Enable support for Enhanced Privileged Access Never (EPAN)"
+ default y
+ depends on ARM64_PAN
+ help
+ Enhanced Privileged Access Never (EPAN) allows Privileged
+ Access Never to be used with Execute-only mappings.
+
+ The feature is detected at runtime, and will remain disabled
+ if the cpu does not implement the feature.
+endmenu # "ARMv8.7 architectural features"
+
+config ARM64_SVE
+ bool "ARM Scalable Vector Extension support"
+ default y
+ help
+ The Scalable Vector Extension (SVE) is an extension to the AArch64
+ execution state which complements and extends the SIMD functionality
+ of the base architecture to support much larger vectors and to enable
+ additional vectorisation opportunities.
+
+ To enable use of this extension on CPUs that implement it, say Y.
+
+ On CPUs that support the SVE2 extensions, this option will enable
+ those too.
+
+ Note that for architectural reasons, firmware _must_ implement SVE
+ support when running on SVE capable hardware. The required support
+ is present in:
+
+ * version 1.5 and later of the ARM Trusted Firmware
+ * the AArch64 boot wrapper since commit 5e1261e08abf
+ ("bootwrapper: SVE: Enable SVE for EL2 and below").
+
+ For other firmware implementations, consult the firmware documentation
+ or vendor.
+
+ If you need the kernel to boot on SVE-capable hardware with broken
+ firmware, you may need to say N here until you get your firmware
+ fixed. Otherwise, you may experience firmware panics or lockups when
+ booting the kernel. If unsure and you are not observing these
+ symptoms, you should assume that it is safe to say Y.
+
+config ARM64_SME
+ bool "ARM Scalable Matrix Extension support"
+ default y
+ depends on ARM64_SVE
+ help
+ The Scalable Matrix Extension (SME) is an extension to the AArch64
+ execution state which utilises a substantial subset of the SVE
+ instruction set, together with the addition of new architectural
+ register state capable of holding two dimensional matrix tiles to
+ enable various matrix operations.
+
+config ARM64_PSEUDO_NMI
+ bool "Support for NMI-like interrupts"
+ select ARM_GIC_V3
+ help
+ Adds support for mimicking Non-Maskable Interrupts through the use of
+ GIC interrupt priority. This support requires version 3 or later of
+ ARM GIC.
+
+ This high priority configuration for interrupts needs to be
+ explicitly enabled by setting the kernel parameter
+ "irqchip.gicv3_pseudo_nmi" to 1.
+
+ If unsure, say N
+
+if ARM64_PSEUDO_NMI
+config ARM64_DEBUG_PRIORITY_MASKING
+ bool "Debug interrupt priority masking"
+ help
+ This adds runtime checks to functions enabling/disabling
+ interrupts when using priority masking. The additional checks verify
+ the validity of ICC_PMR_EL1 when calling concerned functions.
+
+ If unsure, say N
+endif # ARM64_PSEUDO_NMI
+
+config RELOCATABLE
+ bool "Build a relocatable kernel image" if EXPERT
+ select ARCH_HAS_RELR
+ default y
+ help
+ This builds the kernel as a Position Independent Executable (PIE),
+ which retains all relocation metadata required to relocate the
+ kernel binary at runtime to a different virtual address than the
+ address it was linked at.
+ Since AArch64 uses the RELA relocation format, this requires a
+ relocation pass at runtime even if the kernel is loaded at the
+ same address it was linked at.
+
+config RANDOMIZE_BASE
+ bool "Randomize the address of the kernel image"
+ select RELOCATABLE
+ help
+ Randomizes the virtual address at which the kernel image is
+ loaded, as a security feature that deters exploit attempts
+ relying on knowledge of the location of kernel internals.
+
+ It is the bootloader's job to provide entropy, by passing a
+ random u64 value in /chosen/kaslr-seed at kernel entry.
+
+ When booting via the UEFI stub, it will invoke the firmware's
+ EFI_RNG_PROTOCOL implementation (if available) to supply entropy
+ to the kernel proper. In addition, it will randomise the physical
+ location of the kernel Image as well.
+
+ If unsure, say N.
+
+config RANDOMIZE_MODULE_REGION_FULL
+ bool "Randomize the module region over a 2 GB range"
+ depends on RANDOMIZE_BASE
+ default y
+ help
+ Randomizes the location of the module region inside a 2 GB window
+ covering the core kernel. This way, it is less likely for modules
+ to leak information about the location of core kernel data structures
+ but it does imply that function calls between modules and the core
+ kernel will need to be resolved via veneers in the module PLT.
+
+ When this option is not set, the module region will be randomized over
+ a limited range that contains the [_stext, _etext] interval of the
+ core kernel, so branch relocations are almost always in range unless
+ the region is exhausted. In this particular case of region
+ exhaustion, modules might be able to fall back to a larger 2GB area.
+
+config CC_HAVE_STACKPROTECTOR_SYSREG
+ def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
+
+config STACKPROTECTOR_PER_TASK
+ def_bool y
+ depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
+
+config UNWIND_PATCH_PAC_INTO_SCS
+ bool "Enable shadow call stack dynamically using code patching"
+ # needs Clang with https://reviews.llvm.org/D111780 incorporated
+ depends on CC_IS_CLANG && CLANG_VERSION >= 150000
+ depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
+ depends on SHADOW_CALL_STACK
+ select UNWIND_TABLES
+ select DYNAMIC_SCS
+
+endmenu # "Kernel Features"
+
+menu "Boot options"
+
+config ARM64_ACPI_PARKING_PROTOCOL
+ bool "Enable support for the ARM64 ACPI parking protocol"
+ depends on ACPI
+ help
+ Enable support for the ARM64 ACPI parking protocol. If disabled
+ the kernel will not allow booting through the ARM64 ACPI parking
+ protocol even if the corresponding data is present in the ACPI
+ MADT table.
+
+config CMDLINE
+ string "Default kernel command string"
+ default ""
+ help
+ Provide a set of default command-line options at build time by
+ entering them here. As a minimum, you should specify the the
+ root device (e.g. root=/dev/nfs).
+
+choice
+ prompt "Kernel command line type" if CMDLINE != ""
+ default CMDLINE_FROM_BOOTLOADER
+ help
+ Choose how the kernel will handle the provided default kernel
+ command line string.
+
+config CMDLINE_FROM_BOOTLOADER
+ bool "Use bootloader kernel arguments if available"
+ help
+ Uses the command-line options passed by the boot loader. If
+ the boot loader doesn't provide any, the default kernel command
+ string provided in CMDLINE will be used.
+
+config CMDLINE_FORCE
+ bool "Always use the default kernel command string"
+ help
+ Always use the default kernel command string, even if the boot
+ loader passes other arguments to the kernel.
+ This is useful if you cannot or don't want to change the
+ command-line options your boot loader passes to the kernel.
+
+endchoice
+
+config EFI_STUB
+ bool
+
+config EFI
+ bool "UEFI runtime support"
+ depends on OF && !CPU_BIG_ENDIAN
+ depends on KERNEL_MODE_NEON
+ select ARCH_SUPPORTS_ACPI
+ select LIBFDT
+ select UCS2_STRING
+ select EFI_PARAMS_FROM_FDT
+ select EFI_RUNTIME_WRAPPERS
+ select EFI_STUB
+ select EFI_GENERIC_STUB
+ imply IMA_SECURE_AND_OR_TRUSTED_BOOT
+ default y
+ help
+ This option provides support for runtime services provided
+ by UEFI firmware (such as non-volatile variables, realtime
+ clock, and platform reset). A UEFI stub is also provided to
+ allow the kernel to be booted as an EFI application. This
+ is only useful on systems that have UEFI firmware.
+
+config DMI
+ bool "Enable support for SMBIOS (DMI) tables"
+ depends on EFI
+ default y
+ help
+ This enables SMBIOS/DMI feature for systems.
+
+ This option is only useful on systems that have UEFI firmware.
+ However, even with this option, the resultant kernel should
+ continue to boot on existing non-UEFI platforms.
+
+endmenu # "Boot options"
+
+menu "Power management options"
+
+source "kernel/power/Kconfig"
+
+config ARCH_HIBERNATION_POSSIBLE
+ def_bool y
+ depends on CPU_PM
+
+config ARCH_HIBERNATION_HEADER
+ def_bool y
+ depends on HIBERNATION
+
+config ARCH_SUSPEND_POSSIBLE
+ def_bool y
+
+endmenu # "Power management options"
+
+menu "CPU Power Management"
+
+source "drivers/cpuidle/Kconfig"
+
+source "drivers/cpufreq/Kconfig"
+
+endmenu # "CPU Power Management"
+
+source "drivers/acpi/Kconfig"
+
+source "arch/arm64/kvm/Kconfig"
+