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diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
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+# SPDX-License-Identifier: GPL-2.0
+config ARM
+ bool
+ default y
+ select ARCH_32BIT_OFF_T
+ select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE if HAVE_KRETPROBES && FRAME_POINTER && !ARM_UNWIND
+ select ARCH_HAS_BINFMT_FLAT
+ select ARCH_HAS_CPU_FINALIZE_INIT if MMU
+ select ARCH_HAS_CURRENT_STACK_POINTER
+ select ARCH_HAS_DEBUG_VIRTUAL if MMU
+ select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE
+ select ARCH_HAS_ELF_RANDOMIZE
+ select ARCH_HAS_FORTIFY_SOURCE
+ select ARCH_HAS_KEEPINITRD
+ select ARCH_HAS_KCOV
+ select ARCH_HAS_MEMBARRIER_SYNC_CORE
+ select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+ select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
+ select ARCH_HAS_SETUP_DMA_OPS
+ select ARCH_HAS_SET_MEMORY
+ select ARCH_STACKWALK
+ select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
+ select ARCH_HAS_STRICT_MODULE_RWX if MMU
+ select ARCH_HAS_SYNC_DMA_FOR_DEVICE
+ select ARCH_HAS_SYNC_DMA_FOR_CPU
+ select ARCH_HAS_TEARDOWN_DMA_OPS if MMU
+ select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG if CPU_V7 || CPU_V7M || CPU_V6K
+ select ARCH_HAS_GCOV_PROFILE_ALL
+ select ARCH_KEEP_MEMBLOCK
+ select ARCH_HAS_UBSAN_SANITIZE_ALL
+ select ARCH_MIGHT_HAVE_PC_PARPORT
+ select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
+ select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if CPU_V7
+ select ARCH_SUPPORTS_ATOMIC_RMW
+ select ARCH_SUPPORTS_HUGETLBFS if ARM_LPAE
+ select ARCH_USE_BUILTIN_BSWAP
+ select ARCH_USE_CMPXCHG_LOCKREF
+ select ARCH_USE_MEMTEST
+ select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
+ select ARCH_WANT_GENERAL_HUGETLB
+ select ARCH_WANT_IPC_PARSE_VERSION
+ select ARCH_WANT_LD_ORPHAN_WARN
+ select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
+ select BUILDTIME_TABLE_SORT if MMU
+ select COMMON_CLK if !(ARCH_RPC || ARCH_FOOTBRIDGE)
+ select CLONE_BACKWARDS
+ select CPU_PM if SUSPEND || CPU_IDLE
+ select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
+ select DMA_DECLARE_COHERENT
+ select DMA_GLOBAL_POOL if !MMU
+ select DMA_OPS
+ select DMA_NONCOHERENT_MMAP if MMU
+ select EDAC_SUPPORT
+ select EDAC_ATOMIC_SCRUB
+ select GENERIC_ALLOCATOR
+ select GENERIC_ARCH_TOPOLOGY if ARM_CPU_TOPOLOGY
+ select GENERIC_ATOMIC64 if CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI
+ select GENERIC_CLOCKEVENTS_BROADCAST if SMP
+ select GENERIC_IRQ_IPI if SMP
+ select GENERIC_CPU_AUTOPROBE
+ select GENERIC_EARLY_IOREMAP
+ select GENERIC_IDLE_POLL_SETUP
+ select GENERIC_IRQ_MULTI_HANDLER
+ 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_SCHED_CLOCK
+ select GENERIC_SMP_IDLE_THREAD
+ select HARDIRQS_SW_RESEND
+ select HAS_IOPORT
+ select HAVE_ARCH_AUDITSYSCALL if AEABI && !OABI_COMPAT
+ select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
+ select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
+ select HAVE_ARCH_KFENCE if MMU && !XIP_KERNEL
+ select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
+ select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL
+ select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
+ select HAVE_ARCH_MMAP_RND_BITS if MMU
+ select HAVE_ARCH_PFN_VALID
+ select HAVE_ARCH_SECCOMP
+ select HAVE_ARCH_SECCOMP_FILTER if AEABI && !OABI_COMPAT
+ select HAVE_ARCH_THREAD_STRUCT_WHITELIST
+ select HAVE_ARCH_TRACEHOOK
+ select HAVE_ARCH_TRANSPARENT_HUGEPAGE if ARM_LPAE
+ select HAVE_ARM_SMCCC if CPU_V7
+ select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
+ select HAVE_CONTEXT_TRACKING_USER
+ select HAVE_C_RECORDMCOUNT
+ select HAVE_BUILDTIME_MCOUNT_SORT
+ select HAVE_DEBUG_KMEMLEAK if !XIP_KERNEL
+ select HAVE_DMA_CONTIGUOUS if MMU
+ select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
+ select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
+ select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
+ select HAVE_EXIT_THREAD
+ select HAVE_FAST_GUP if ARM_LPAE
+ select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
+ select HAVE_FUNCTION_ERROR_INJECTION
+ select HAVE_FUNCTION_GRAPH_TRACER
+ select HAVE_FUNCTION_TRACER if !XIP_KERNEL
+ select HAVE_GCC_PLUGINS
+ select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7)
+ select HAVE_IRQ_TIME_ACCOUNTING
+ select HAVE_KERNEL_GZIP
+ select HAVE_KERNEL_LZ4
+ select HAVE_KERNEL_LZMA
+ select HAVE_KERNEL_LZO
+ select HAVE_KERNEL_XZ
+ select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
+ select HAVE_KRETPROBES if HAVE_KPROBES
+ select HAVE_MOD_ARCH_SPECIFIC
+ select HAVE_NMI
+ select HAVE_OPTPROBES if !THUMB2_KERNEL
+ select HAVE_PCI if MMU
+ select HAVE_PERF_EVENTS
+ select HAVE_PERF_REGS
+ select HAVE_PERF_USER_STACK_DUMP
+ select MMU_GATHER_RCU_TABLE_FREE if SMP && ARM_LPAE
+ select HAVE_REGS_AND_STACK_ACCESS_API
+ select HAVE_RSEQ
+ select HAVE_STACKPROTECTOR
+ select HAVE_SYSCALL_TRACEPOINTS
+ select HAVE_UID16
+ select HAVE_VIRT_CPU_ACCOUNTING_GEN
+ select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
+ select IRQ_FORCED_THREADING
+ select LOCK_MM_AND_FIND_VMA
+ select MODULES_USE_ELF_REL
+ select NEED_DMA_MAP_STATE
+ select OF_EARLY_FLATTREE if OF
+ select OLD_SIGACTION
+ select OLD_SIGSUSPEND3
+ select PCI_DOMAINS_GENERIC if PCI
+ select PCI_SYSCALL if PCI
+ select PERF_USE_VMALLOC
+ select RTC_LIB
+ select SPARSE_IRQ if !(ARCH_FOOTBRIDGE || ARCH_RPC)
+ select SYS_SUPPORTS_APM_EMULATION
+ select THREAD_INFO_IN_TASK
+ select TIMER_OF if OF
+ select HAVE_ARCH_VMAP_STACK if MMU && ARM_HAS_GROUP_RELOCS
+ select TRACE_IRQFLAGS_SUPPORT if !CPU_V7M
+ select USE_OF if !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
+ # Above selects are sorted alphabetically; please add new ones
+ # according to that. Thanks.
+ help
+ The ARM series is a line of low-power-consumption RISC chip designs
+ licensed by ARM Ltd and targeted at embedded applications and
+ handhelds such as the Compaq IPAQ. ARM-based PCs are no longer
+ manufactured, but legacy ARM-based PC hardware remains popular in
+ Europe. There is an ARM Linux project with a web page at
+ <http://www.arm.linux.org.uk/>.
+
+config ARM_HAS_GROUP_RELOCS
+ def_bool y
+ depends on !LD_IS_LLD || LLD_VERSION >= 140000
+ depends on !COMPILE_TEST
+ help
+ Whether or not to use R_ARM_ALU_PC_Gn or R_ARM_LDR_PC_Gn group
+ relocations, which have been around for a long time, but were not
+ supported in LLD until version 14. The combined range is -/+ 256 MiB,
+ which is usually sufficient, but not for allyesconfig, so we disable
+ this feature when doing compile testing.
+
+config ARM_DMA_USE_IOMMU
+ bool
+ select NEED_SG_DMA_LENGTH
+
+if ARM_DMA_USE_IOMMU
+
+config ARM_DMA_IOMMU_ALIGNMENT
+ int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
+ range 4 9
+ default 8
+ help
+ DMA mapping framework by default aligns all buffers to the smallest
+ PAGE_SIZE order which is greater than or equal to the requested buffer
+ size. This works well for buffers up to a few hundreds kilobytes, but
+ for larger buffers it just a waste of address space. Drivers which has
+ relatively small addressing window (like 64Mib) might run out of
+ virtual space with just a few allocations.
+
+ With this parameter you can specify the maximum PAGE_SIZE order for
+ DMA IOMMU buffers. Larger buffers will be aligned only to this
+ specified order. The order is expressed as a power of two multiplied
+ by the PAGE_SIZE.
+
+endif
+
+config SYS_SUPPORTS_APM_EMULATION
+ bool
+
+config HAVE_TCM
+ bool
+ select GENERIC_ALLOCATOR
+
+config HAVE_PROC_CPU
+ bool
+
+config NO_IOPORT_MAP
+ bool
+
+config SBUS
+ bool
+
+config STACKTRACE_SUPPORT
+ bool
+ default y
+
+config LOCKDEP_SUPPORT
+ bool
+ default y
+
+config ARCH_HAS_ILOG2_U32
+ bool
+
+config ARCH_HAS_ILOG2_U64
+ bool
+
+config ARCH_HAS_BANDGAP
+ bool
+
+config FIX_EARLYCON_MEM
+ def_bool y if MMU
+
+config GENERIC_HWEIGHT
+ bool
+ default y
+
+config GENERIC_CALIBRATE_DELAY
+ bool
+ default y
+
+config ARCH_MAY_HAVE_PC_FDC
+ bool
+
+config ARCH_SUPPORTS_UPROBES
+ def_bool y
+
+config GENERIC_ISA_DMA
+ bool
+
+config FIQ
+ bool
+
+config ARCH_MTD_XIP
+ bool
+
+config ARM_PATCH_PHYS_VIRT
+ bool "Patch physical to virtual translations at runtime" if !ARCH_MULTIPLATFORM
+ default y
+ depends on MMU
+ help
+ Patch phys-to-virt and virt-to-phys translation functions at
+ boot and module load time according to the position of the
+ kernel in system memory.
+
+ This can only be used with non-XIP MMU kernels where the base
+ of physical memory is at a 2 MiB boundary.
+
+ Only disable this option if you know that you do not require
+ this feature (eg, building a kernel for a single machine) and
+ you need to shrink the kernel to the minimal size.
+
+config NEED_MACH_IO_H
+ bool
+ help
+ Select this when mach/io.h is required to provide special
+ definitions for this platform. The need for mach/io.h should
+ be avoided when possible.
+
+config NEED_MACH_MEMORY_H
+ bool
+ help
+ Select this when mach/memory.h is required to provide special
+ definitions for this platform. The need for mach/memory.h should
+ be avoided when possible.
+
+config PHYS_OFFSET
+ hex "Physical address of main memory" if MMU
+ depends on !ARM_PATCH_PHYS_VIRT || !AUTO_ZRELADDR
+ default DRAM_BASE if !MMU
+ default 0x00000000 if ARCH_FOOTBRIDGE
+ default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
+ default 0xa0000000 if ARCH_PXA
+ default 0xc0000000 if ARCH_EP93XX || ARCH_SA1100
+ default 0
+ help
+ Please provide the physical address corresponding to the
+ location of main memory in your system.
+
+config GENERIC_BUG
+ def_bool y
+ depends on BUG
+
+config PGTABLE_LEVELS
+ int
+ default 3 if ARM_LPAE
+ default 2
+
+menu "System Type"
+
+config MMU
+ bool "MMU-based Paged Memory Management Support"
+ default y
+ help
+ Select if you want MMU-based virtualised addressing space
+ support by paged memory management. If unsure, say 'Y'.
+
+config ARM_SINGLE_ARMV7M
+ def_bool !MMU
+ select ARM_NVIC
+ select CPU_V7M
+ select NO_IOPORT_MAP
+
+config ARCH_MMAP_RND_BITS_MIN
+ default 8
+
+config ARCH_MMAP_RND_BITS_MAX
+ default 14 if PAGE_OFFSET=0x40000000
+ default 15 if PAGE_OFFSET=0x80000000
+ default 16
+
+config ARCH_MULTIPLATFORM
+ bool "Require kernel to be portable to multiple machines" if EXPERT
+ depends on MMU && !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
+ default y
+ help
+ In general, all Arm machines can be supported in a single
+ kernel image, covering either Armv4/v5 or Armv6/v7.
+
+ However, some configuration options require hardcoding machine
+ specific physical addresses or enable errata workarounds that may
+ break other machines.
+
+ Selecting N here allows using those options, including
+ DEBUG_UNCOMPRESS, XIP_KERNEL and ZBOOT_ROM. If unsure, say Y.
+
+menu "Platform selection"
+ depends on MMU
+
+comment "CPU Core family selection"
+
+config ARCH_MULTI_V4
+ bool "ARMv4 based platforms (FA526, StrongARM)"
+ depends on !ARCH_MULTI_V6_V7
+ # https://github.com/llvm/llvm-project/issues/50764
+ depends on !LD_IS_LLD || LLD_VERSION >= 160000
+ select ARCH_MULTI_V4_V5
+ select CPU_FA526 if !(CPU_SA110 || CPU_SA1100)
+
+config ARCH_MULTI_V4T
+ bool "ARMv4T based platforms (ARM720T, ARM920T, ...)"
+ depends on !ARCH_MULTI_V6_V7
+ # https://github.com/llvm/llvm-project/issues/50764
+ depends on !LD_IS_LLD || LLD_VERSION >= 160000
+ select ARCH_MULTI_V4_V5
+ select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \
+ CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \
+ CPU_ARM925T || CPU_ARM940T)
+
+config ARCH_MULTI_V5
+ bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)"
+ depends on !ARCH_MULTI_V6_V7
+ select ARCH_MULTI_V4_V5
+ select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \
+ CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
+ CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON)
+
+config ARCH_MULTI_V4_V5
+ bool
+
+config ARCH_MULTI_V6
+ bool "ARMv6 based platforms (ARM11)"
+ select ARCH_MULTI_V6_V7
+ select CPU_V6K
+
+config ARCH_MULTI_V7
+ bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
+ default y
+ select ARCH_MULTI_V6_V7
+ select CPU_V7
+ select HAVE_SMP
+
+config ARCH_MULTI_V6_V7
+ bool
+ select MIGHT_HAVE_CACHE_L2X0
+
+config ARCH_MULTI_CPU_AUTO
+ def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7)
+ select ARCH_MULTI_V5
+
+endmenu
+
+config ARCH_VIRT
+ bool "Dummy Virtual Machine"
+ depends on ARCH_MULTI_V7
+ select ARM_AMBA
+ select ARM_GIC
+ select ARM_GIC_V2M if PCI
+ select ARM_GIC_V3
+ select ARM_GIC_V3_ITS if PCI
+ select ARM_PSCI
+ select HAVE_ARM_ARCH_TIMER
+
+config ARCH_AIROHA
+ bool "Airoha SoC Support"
+ depends on ARCH_MULTI_V7
+ select ARM_AMBA
+ select ARM_GIC
+ select ARM_GIC_V3
+ select ARM_PSCI
+ select HAVE_ARM_ARCH_TIMER
+ help
+ Support for Airoha EN7523 SoCs
+
+#
+# This is sorted alphabetically by mach-* pathname. However, plat-*
+# Kconfigs may be included either alphabetically (according to the
+# plat- suffix) or along side the corresponding mach-* source.
+#
+source "arch/arm/mach-actions/Kconfig"
+
+source "arch/arm/mach-alpine/Kconfig"
+
+source "arch/arm/mach-artpec/Kconfig"
+
+source "arch/arm/mach-asm9260/Kconfig"
+
+source "arch/arm/mach-aspeed/Kconfig"
+
+source "arch/arm/mach-at91/Kconfig"
+
+source "arch/arm/mach-axxia/Kconfig"
+
+source "arch/arm/mach-bcm/Kconfig"
+
+source "arch/arm/mach-berlin/Kconfig"
+
+source "arch/arm/mach-clps711x/Kconfig"
+
+source "arch/arm/mach-davinci/Kconfig"
+
+source "arch/arm/mach-digicolor/Kconfig"
+
+source "arch/arm/mach-dove/Kconfig"
+
+source "arch/arm/mach-ep93xx/Kconfig"
+
+source "arch/arm/mach-exynos/Kconfig"
+
+source "arch/arm/mach-footbridge/Kconfig"
+
+source "arch/arm/mach-gemini/Kconfig"
+
+source "arch/arm/mach-highbank/Kconfig"
+
+source "arch/arm/mach-hisi/Kconfig"
+
+source "arch/arm/mach-hpe/Kconfig"
+
+source "arch/arm/mach-imx/Kconfig"
+
+source "arch/arm/mach-ixp4xx/Kconfig"
+
+source "arch/arm/mach-keystone/Kconfig"
+
+source "arch/arm/mach-lpc32xx/Kconfig"
+
+source "arch/arm/mach-mediatek/Kconfig"
+
+source "arch/arm/mach-meson/Kconfig"
+
+source "arch/arm/mach-milbeaut/Kconfig"
+
+source "arch/arm/mach-mmp/Kconfig"
+
+source "arch/arm/mach-moxart/Kconfig"
+
+source "arch/arm/mach-mstar/Kconfig"
+
+source "arch/arm/mach-mv78xx0/Kconfig"
+
+source "arch/arm/mach-mvebu/Kconfig"
+
+source "arch/arm/mach-mxs/Kconfig"
+
+source "arch/arm/mach-nomadik/Kconfig"
+
+source "arch/arm/mach-npcm/Kconfig"
+
+source "arch/arm/mach-nspire/Kconfig"
+
+source "arch/arm/mach-omap1/Kconfig"
+
+source "arch/arm/mach-omap2/Kconfig"
+
+source "arch/arm/mach-orion5x/Kconfig"
+
+source "arch/arm/mach-pxa/Kconfig"
+
+source "arch/arm/mach-qcom/Kconfig"
+
+source "arch/arm/mach-rda/Kconfig"
+
+source "arch/arm/mach-realtek/Kconfig"
+
+source "arch/arm/mach-rpc/Kconfig"
+
+source "arch/arm/mach-rockchip/Kconfig"
+
+source "arch/arm/mach-s3c/Kconfig"
+
+source "arch/arm/mach-s5pv210/Kconfig"
+
+source "arch/arm/mach-sa1100/Kconfig"
+
+source "arch/arm/mach-shmobile/Kconfig"
+
+source "arch/arm/mach-socfpga/Kconfig"
+
+source "arch/arm/mach-spear/Kconfig"
+
+source "arch/arm/mach-sti/Kconfig"
+
+source "arch/arm/mach-stm32/Kconfig"
+
+source "arch/arm/mach-sunplus/Kconfig"
+
+source "arch/arm/mach-sunxi/Kconfig"
+
+source "arch/arm/mach-tegra/Kconfig"
+
+source "arch/arm/mach-uniphier/Kconfig"
+
+source "arch/arm/mach-ux500/Kconfig"
+
+source "arch/arm/mach-versatile/Kconfig"
+
+source "arch/arm/mach-vt8500/Kconfig"
+
+source "arch/arm/mach-zynq/Kconfig"
+
+# ARMv7-M architecture
+config ARCH_LPC18XX
+ bool "NXP LPC18xx/LPC43xx"
+ depends on ARM_SINGLE_ARMV7M
+ select ARCH_HAS_RESET_CONTROLLER
+ select ARM_AMBA
+ select CLKSRC_LPC32XX
+ select PINCTRL
+ help
+ Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4
+ high performance microcontrollers.
+
+config ARCH_MPS2
+ bool "ARM MPS2 platform"
+ depends on ARM_SINGLE_ARMV7M
+ select ARM_AMBA
+ select CLKSRC_MPS2
+ help
+ Support for Cortex-M Prototyping System (or V2M-MPS2) which comes
+ with a range of available cores like Cortex-M3/M4/M7.
+
+ Please, note that depends which Application Note is used memory map
+ for the platform may vary, so adjustment of RAM base might be needed.
+
+# Definitions to make life easier
+config ARCH_ACORN
+ bool
+
+config PLAT_ORION
+ bool
+ select CLKSRC_MMIO
+ select GENERIC_IRQ_CHIP
+ select IRQ_DOMAIN
+
+config PLAT_ORION_LEGACY
+ bool
+ select PLAT_ORION
+
+config PLAT_VERSATILE
+ bool
+
+source "arch/arm/mm/Kconfig"
+
+config IWMMXT
+ bool "Enable iWMMXt support"
+ depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
+ default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
+ help
+ Enable support for iWMMXt context switching at run time if
+ running on a CPU that supports it.
+
+if !MMU
+source "arch/arm/Kconfig-nommu"
+endif
+
+config PJ4B_ERRATA_4742
+ bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
+ depends on CPU_PJ4B && MACH_ARMADA_370
+ default y
+ help
+ When coming out of either a Wait for Interrupt (WFI) or a Wait for
+ Event (WFE) IDLE states, a specific timing sensitivity exists between
+ the retiring WFI/WFE instructions and the newly issued subsequent
+ instructions. This sensitivity can result in a CPU hang scenario.
+ Workaround:
+ The software must insert either a Data Synchronization Barrier (DSB)
+ or Data Memory Barrier (DMB) command immediately after the WFI/WFE
+ instruction
+
+config ARM_ERRATA_326103
+ bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
+ depends on CPU_V6
+ help
+ Executing a SWP instruction to read-only memory does not set bit 11
+ of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
+ treat the access as a read, preventing a COW from occurring and
+ causing the faulting task to livelock.
+
+config ARM_ERRATA_411920
+ bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
+ depends on CPU_V6 || CPU_V6K
+ help
+ Invalidation of the Instruction Cache operation can
+ fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
+ It does not affect the MPCore. This option enables the ARM Ltd.
+ recommended workaround.
+
+config ARM_ERRATA_430973
+ bool "ARM errata: Stale prediction on replaced interworking branch"
+ depends on CPU_V7
+ help
+ This option enables the workaround for the 430973 Cortex-A8
+ r1p* erratum. If a code sequence containing an ARM/Thumb
+ interworking branch is replaced with another code sequence at the
+ same virtual address, whether due to self-modifying code or virtual
+ to physical address re-mapping, Cortex-A8 does not recover from the
+ stale interworking branch prediction. This results in Cortex-A8
+ executing the new code sequence in the incorrect ARM or Thumb state.
+ The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
+ and also flushes the branch target cache at every context switch.
+ Note that setting specific bits in the ACTLR register may not be
+ available in non-secure mode.
+
+config ARM_ERRATA_458693
+ bool "ARM errata: Processor deadlock when a false hazard is created"
+ depends on CPU_V7
+ depends on !ARCH_MULTIPLATFORM
+ help
+ This option enables the workaround for the 458693 Cortex-A8 (r2p0)
+ erratum. For very specific sequences of memory operations, it is
+ possible for a hazard condition intended for a cache line to instead
+ be incorrectly associated with a different cache line. This false
+ hazard might then cause a processor deadlock. The workaround enables
+ the L1 caching of the NEON accesses and disables the PLD instruction
+ in the ACTLR register. Note that setting specific bits in the ACTLR
+ register may not be available in non-secure mode and thus is not
+ available on a multiplatform kernel. This should be applied by the
+ bootloader instead.
+
+config ARM_ERRATA_460075
+ bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
+ depends on CPU_V7
+ depends on !ARCH_MULTIPLATFORM
+ help
+ This option enables the workaround for the 460075 Cortex-A8 (r2p0)
+ erratum. Any asynchronous access to the L2 cache may encounter a
+ situation in which recent store transactions to the L2 cache are lost
+ and overwritten with stale memory contents from external memory. The
+ workaround disables the write-allocate mode for the L2 cache via the
+ ACTLR register. Note that setting specific bits in the ACTLR register
+ may not be available in non-secure mode and thus is not available on
+ a multiplatform kernel. This should be applied by the bootloader
+ instead.
+
+config ARM_ERRATA_742230
+ bool "ARM errata: DMB operation may be faulty"
+ depends on CPU_V7 && SMP
+ depends on !ARCH_MULTIPLATFORM
+ help
+ This option enables the workaround for the 742230 Cortex-A9
+ (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
+ between two write operations may not ensure the correct visibility
+ ordering of the two writes. This workaround sets a specific bit in
+ the diagnostic register of the Cortex-A9 which causes the DMB
+ instruction to behave as a DSB, ensuring the correct behaviour of
+ the two writes. Note that setting specific bits in the diagnostics
+ register may not be available in non-secure mode and thus is not
+ available on a multiplatform kernel. This should be applied by the
+ bootloader instead.
+
+config ARM_ERRATA_742231
+ bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
+ depends on CPU_V7 && SMP
+ depends on !ARCH_MULTIPLATFORM
+ help
+ This option enables the workaround for the 742231 Cortex-A9
+ (r2p0..r2p2) erratum. Under certain conditions, specific to the
+ Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
+ accessing some data located in the same cache line, may get corrupted
+ data due to bad handling of the address hazard when the line gets
+ replaced from one of the CPUs at the same time as another CPU is
+ accessing it. This workaround sets specific bits in the diagnostic
+ register of the Cortex-A9 which reduces the linefill issuing
+ capabilities of the processor. Note that setting specific bits in the
+ diagnostics register may not be available in non-secure mode and thus
+ is not available on a multiplatform kernel. This should be applied by
+ the bootloader instead.
+
+config ARM_ERRATA_643719
+ bool "ARM errata: LoUIS bit field in CLIDR register is incorrect"
+ depends on CPU_V7 && SMP
+ default y
+ help
+ This option enables the workaround for the 643719 Cortex-A9 (prior to
+ r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR
+ register returns zero when it should return one. The workaround
+ corrects this value, ensuring cache maintenance operations which use
+ it behave as intended and avoiding data corruption.
+
+config ARM_ERRATA_720789
+ bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"
+ depends on CPU_V7
+ help
+ This option enables the workaround for the 720789 Cortex-A9 (prior to
+ r2p0) erratum. A faulty ASID can be sent to the other CPUs for the
+ broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.
+ As a consequence of this erratum, some TLB entries which should be
+ invalidated are not, resulting in an incoherency in the system page
+ tables. The workaround changes the TLB flushing routines to invalidate
+ entries regardless of the ASID.
+
+config ARM_ERRATA_743622
+ bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption"
+ depends on CPU_V7
+ depends on !ARCH_MULTIPLATFORM
+ help
+ This option enables the workaround for the 743622 Cortex-A9
+ (r2p*) erratum. Under very rare conditions, a faulty
+ optimisation in the Cortex-A9 Store Buffer may lead to data
+ corruption. This workaround sets a specific bit in the diagnostic
+ register of the Cortex-A9 which disables the Store Buffer
+ optimisation, preventing the defect from occurring. This has no
+ visible impact on the overall performance or power consumption of the
+ processor. Note that setting specific bits in the diagnostics register
+ may not be available in non-secure mode and thus is not available on a
+ multiplatform kernel. This should be applied by the bootloader instead.
+
+config ARM_ERRATA_751472
+ bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"
+ depends on CPU_V7
+ depends on !ARCH_MULTIPLATFORM
+ help
+ This option enables the workaround for the 751472 Cortex-A9 (prior
+ to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the
+ completion of a following broadcasted operation if the second
+ operation is received by a CPU before the ICIALLUIS has completed,
+ potentially leading to corrupted entries in the cache or TLB.
+ Note that setting specific bits in the diagnostics register may
+ not be available in non-secure mode and thus is not available on
+ a multiplatform kernel. This should be applied by the bootloader
+ instead.
+
+config ARM_ERRATA_754322
+ bool "ARM errata: possible faulty MMU translations following an ASID switch"
+ depends on CPU_V7
+ help
+ This option enables the workaround for the 754322 Cortex-A9 (r2p*,
+ r3p*) erratum. A speculative memory access may cause a page table walk
+ which starts prior to an ASID switch but completes afterwards. This
+ can populate the micro-TLB with a stale entry which may be hit with
+ the new ASID. This workaround places two dsb instructions in the mm
+ switching code so that no page table walks can cross the ASID switch.
+
+config ARM_ERRATA_754327
+ bool "ARM errata: no automatic Store Buffer drain"
+ depends on CPU_V7 && SMP
+ help
+ This option enables the workaround for the 754327 Cortex-A9 (prior to
+ r2p0) erratum. The Store Buffer does not have any automatic draining
+ mechanism and therefore a livelock may occur if an external agent
+ continuously polls a memory location waiting to observe an update.
+ This workaround defines cpu_relax() as smp_mb(), preventing correctly
+ written polling loops from denying visibility of updates to memory.
+
+config ARM_ERRATA_364296
+ bool "ARM errata: Possible cache data corruption with hit-under-miss enabled"
+ depends on CPU_V6
+ help
+ This options enables the workaround for the 364296 ARM1136
+ r0p2 erratum (possible cache data corruption with
+ hit-under-miss enabled). It sets the undocumented bit 31 in
+ the auxiliary control register and the FI bit in the control
+ register, thus disabling hit-under-miss without putting the
+ processor into full low interrupt latency mode. ARM11MPCore
+ is not affected.
+
+config ARM_ERRATA_764369
+ bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
+ depends on CPU_V7 && SMP
+ help
+ This option enables the workaround for erratum 764369
+ affecting Cortex-A9 MPCore with two or more processors (all
+ current revisions). Under certain timing circumstances, a data
+ cache line maintenance operation by MVA targeting an Inner
+ Shareable memory region may fail to proceed up to either the
+ Point of Coherency or to the Point of Unification of the
+ system. This workaround adds a DSB instruction before the
+ relevant cache maintenance functions and sets a specific bit
+ in the diagnostic control register of the SCU.
+
+config ARM_ERRATA_764319
+ bool "ARM errata: Read to DBGPRSR and DBGOSLSR may generate Undefined instruction"
+ depends on CPU_V7
+ help
+ This option enables the workaround for the 764319 Cortex A-9 erratum.
+ CP14 read accesses to the DBGPRSR and DBGOSLSR registers generate an
+ unexpected Undefined Instruction exception when the DBGSWENABLE
+ external pin is set to 0, even when the CP14 accesses are performed
+ from a privileged mode. This work around catches the exception in a
+ way the kernel does not stop execution.
+
+config ARM_ERRATA_775420
+ bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
+ depends on CPU_V7
+ help
+ This option enables the workaround for the 775420 Cortex-A9 (r2p2,
+ r2p6,r2p8,r2p10,r3p0) erratum. In case a data cache maintenance
+ operation aborts with MMU exception, it might cause the processor
+ to deadlock. This workaround puts DSB before executing ISB if
+ an abort may occur on cache maintenance.
+
+config ARM_ERRATA_798181
+ bool "ARM errata: TLBI/DSB failure on Cortex-A15"
+ depends on CPU_V7 && SMP
+ help
+ On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
+ adequately shooting down all use of the old entries. This
+ option enables the Linux kernel workaround for this erratum
+ which sends an IPI to the CPUs that are running the same ASID
+ as the one being invalidated.
+
+config ARM_ERRATA_773022
+ bool "ARM errata: incorrect instructions may be executed from loop buffer"
+ depends on CPU_V7
+ help
+ This option enables the workaround for the 773022 Cortex-A15
+ (up to r0p4) erratum. In certain rare sequences of code, the
+ loop buffer may deliver incorrect instructions. This
+ workaround disables the loop buffer to avoid the erratum.
+
+config ARM_ERRATA_818325_852422
+ bool "ARM errata: A12: some seqs of opposed cond code instrs => deadlock or corruption"
+ depends on CPU_V7
+ help
+ This option enables the workaround for:
+ - Cortex-A12 818325: Execution of an UNPREDICTABLE STR or STM
+ instruction might deadlock. Fixed in r0p1.
+ - Cortex-A12 852422: Execution of a sequence of instructions might
+ lead to either a data corruption or a CPU deadlock. Not fixed in
+ any Cortex-A12 cores yet.
+ This workaround for all both errata involves setting bit[12] of the
+ Feature Register. This bit disables an optimisation applied to a
+ sequence of 2 instructions that use opposing condition codes.
+
+config ARM_ERRATA_821420
+ bool "ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock"
+ depends on CPU_V7
+ help
+ This option enables the workaround for the 821420 Cortex-A12
+ (all revs) erratum. In very rare timing conditions, a sequence
+ of VMOV to Core registers instructions, for which the second
+ one is in the shadow of a branch or abort, can lead to a
+ deadlock when the VMOV instructions are issued out-of-order.
+
+config ARM_ERRATA_825619
+ bool "ARM errata: A12: DMB NSHST/ISHST mixed ... might cause deadlock"
+ depends on CPU_V7
+ help
+ This option enables the workaround for the 825619 Cortex-A12
+ (all revs) erratum. Within rare timing constraints, executing a
+ DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable
+ and Device/Strongly-Ordered loads and stores might cause deadlock
+
+config ARM_ERRATA_857271
+ bool "ARM errata: A12: CPU might deadlock under some very rare internal conditions"
+ depends on CPU_V7
+ help
+ This option enables the workaround for the 857271 Cortex-A12
+ (all revs) erratum. Under very rare timing conditions, the CPU might
+ hang. The workaround is expected to have a < 1% performance impact.
+
+config ARM_ERRATA_852421
+ bool "ARM errata: A17: DMB ST might fail to create order between stores"
+ depends on CPU_V7
+ help
+ This option enables the workaround for the 852421 Cortex-A17
+ (r1p0, r1p1, r1p2) erratum. Under very rare timing conditions,
+ execution of a DMB ST instruction might fail to properly order
+ stores from GroupA and stores from GroupB.
+
+config ARM_ERRATA_852423
+ bool "ARM errata: A17: some seqs of opposed cond code instrs => deadlock or corruption"
+ depends on CPU_V7
+ help
+ This option enables the workaround for:
+ - Cortex-A17 852423: Execution of a sequence of instructions might
+ lead to either a data corruption or a CPU deadlock. Not fixed in
+ any Cortex-A17 cores yet.
+ This is identical to Cortex-A12 erratum 852422. It is a separate
+ config option from the A12 erratum due to the way errata are checked
+ for and handled.
+
+config ARM_ERRATA_857272
+ bool "ARM errata: A17: CPU might deadlock under some very rare internal conditions"
+ depends on CPU_V7
+ help
+ This option enables the workaround for the 857272 Cortex-A17 erratum.
+ This erratum is not known to be fixed in any A17 revision.
+ This is identical to Cortex-A12 erratum 857271. It is a separate
+ config option from the A12 erratum due to the way errata are checked
+ for and handled.
+
+endmenu
+
+source "arch/arm/common/Kconfig"
+
+menu "Bus support"
+
+config ISA
+ bool
+ help
+ Find out whether you have ISA slots on your motherboard. ISA is the
+ name of a bus system, i.e. the way the CPU talks to the other stuff
+ inside your box. Other bus systems are PCI, EISA, MicroChannel
+ (MCA) or VESA. ISA is an older system, now being displaced by PCI;
+ newer boards don't support it. If you have ISA, say Y, otherwise N.
+
+# Select ISA DMA interface
+config ISA_DMA_API
+ bool
+
+config ARM_ERRATA_814220
+ bool "ARM errata: Cache maintenance by set/way operations can execute out of order"
+ depends on CPU_V7
+ help
+ The v7 ARM states that all cache and branch predictor maintenance
+ operations that do not specify an address execute, relative to
+ each other, in program order.
+ However, because of this erratum, an L2 set/way cache maintenance
+ operation can overtake an L1 set/way cache maintenance operation.
+ This ERRATA only affected the Cortex-A7 and present in r0p2, r0p3,
+ r0p4, r0p5.
+
+endmenu
+
+menu "Kernel Features"
+
+config HAVE_SMP
+ bool
+ help
+ This option should be selected by machines which have an SMP-
+ capable CPU.
+
+ The only effect of this option is to make the SMP-related
+ options available to the user for configuration.
+
+config SMP
+ bool "Symmetric Multi-Processing"
+ depends on CPU_V6K || CPU_V7
+ depends on HAVE_SMP
+ depends on MMU || ARM_MPU
+ select IRQ_WORK
+ help
+ This enables support for systems with more than one CPU. If you have
+ a system with only one CPU, say N. If you have a system with more
+ than one CPU, say Y.
+
+ If you say N here, the kernel will run on uni- and multiprocessor
+ machines, but will use only one CPU of a multiprocessor machine. If
+ you say Y here, the kernel will run on many, but not all,
+ uniprocessor machines. On a uniprocessor machine, the kernel
+ will run faster if you say N here.
+
+ See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
+ <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
+ <http://tldp.org/HOWTO/SMP-HOWTO.html>.
+
+ If you don't know what to do here, say N.
+
+config SMP_ON_UP
+ bool "Allow booting SMP kernel on uniprocessor systems"
+ depends on SMP && MMU
+ default y
+ help
+ SMP kernels contain instructions which fail on non-SMP processors.
+ Enabling this option allows the kernel to modify itself to make
+ these instructions safe. Disabling it allows about 1K of space
+ savings.
+
+ If you don't know what to do here, say Y.
+
+
+config CURRENT_POINTER_IN_TPIDRURO
+ def_bool y
+ depends on CPU_32v6K && !CPU_V6
+
+config IRQSTACKS
+ def_bool y
+ select HAVE_IRQ_EXIT_ON_IRQ_STACK
+ select HAVE_SOFTIRQ_ON_OWN_STACK
+
+config ARM_CPU_TOPOLOGY
+ bool "Support cpu topology definition"
+ depends on SMP && CPU_V7
+ default y
+ help
+ Support ARM cpu topology definition. The MPIDR register defines
+ affinity between processors which is then used to describe the cpu
+ topology of an ARM System.
+
+config SCHED_MC
+ bool "Multi-core scheduler support"
+ depends on ARM_CPU_TOPOLOGY
+ 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_SMT
+ bool "SMT scheduler support"
+ depends on ARM_CPU_TOPOLOGY
+ 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 HAVE_ARM_SCU
+ bool
+ help
+ This option enables support for the ARM snoop control unit
+
+config HAVE_ARM_ARCH_TIMER
+ bool "Architected timer support"
+ depends on CPU_V7
+ select ARM_ARCH_TIMER
+ help
+ This option enables support for the ARM architected timer
+
+config HAVE_ARM_TWD
+ bool
+ help
+ This options enables support for the ARM timer and watchdog unit
+
+config MCPM
+ bool "Multi-Cluster Power Management"
+ depends on CPU_V7 && SMP
+ help
+ This option provides the common power management infrastructure
+ for (multi-)cluster based systems, such as big.LITTLE based
+ systems.
+
+config MCPM_QUAD_CLUSTER
+ bool
+ depends on MCPM
+ help
+ To avoid wasting resources unnecessarily, MCPM only supports up
+ to 2 clusters by default.
+ Platforms with 3 or 4 clusters that use MCPM must select this
+ option to allow the additional clusters to be managed.
+
+config BIG_LITTLE
+ bool "big.LITTLE support (Experimental)"
+ depends on CPU_V7 && SMP
+ select MCPM
+ help
+ This option enables support selections for the big.LITTLE
+ system architecture.
+
+config BL_SWITCHER
+ bool "big.LITTLE switcher support"
+ depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC
+ select CPU_PM
+ help
+ The big.LITTLE "switcher" provides the core functionality to
+ transparently handle transition between a cluster of A15's
+ and a cluster of A7's in a big.LITTLE system.
+
+config BL_SWITCHER_DUMMY_IF
+ tristate "Simple big.LITTLE switcher user interface"
+ depends on BL_SWITCHER && DEBUG_KERNEL
+ help
+ This is a simple and dummy char dev interface to control
+ the big.LITTLE switcher core code. It is meant for
+ debugging purposes only.
+
+choice
+ prompt "Memory split"
+ depends on MMU
+ default VMSPLIT_3G
+ help
+ Select the desired split between kernel and user memory.
+
+ If you are not absolutely sure what you are doing, leave this
+ option alone!
+
+ config VMSPLIT_3G
+ bool "3G/1G user/kernel split"
+ config VMSPLIT_3G_OPT
+ depends on !ARM_LPAE
+ bool "3G/1G user/kernel split (for full 1G low memory)"
+ config VMSPLIT_2G
+ bool "2G/2G user/kernel split"
+ config VMSPLIT_1G
+ bool "1G/3G user/kernel split"
+endchoice
+
+config PAGE_OFFSET
+ hex
+ default PHYS_OFFSET if !MMU
+ default 0x40000000 if VMSPLIT_1G
+ default 0x80000000 if VMSPLIT_2G
+ default 0xB0000000 if VMSPLIT_3G_OPT
+ default 0xC0000000
+
+config KASAN_SHADOW_OFFSET
+ hex
+ depends on KASAN
+ default 0x1f000000 if PAGE_OFFSET=0x40000000
+ default 0x5f000000 if PAGE_OFFSET=0x80000000
+ default 0x9f000000 if PAGE_OFFSET=0xC0000000
+ default 0x8f000000 if PAGE_OFFSET=0xB0000000
+ default 0xffffffff
+
+config NR_CPUS
+ int "Maximum number of CPUs (2-32)"
+ range 2 16 if DEBUG_KMAP_LOCAL
+ range 2 32 if !DEBUG_KMAP_LOCAL
+ depends on SMP
+ default "4"
+ help
+ The maximum number of CPUs that the kernel can support.
+ Up to 32 CPUs can be supported, or up to 16 if kmap_local()
+ debugging is enabled, which uses half of the per-CPU fixmap
+ slots as guard regions.
+
+config HOTPLUG_CPU
+ bool "Support for hot-pluggable CPUs"
+ depends on SMP
+ 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.
+
+config ARM_PSCI
+ bool "Support for the ARM Power State Coordination Interface (PSCI)"
+ depends on HAVE_ARM_SMCCC
+ select ARM_PSCI_FW
+ help
+ Say Y here if you want Linux to communicate with system firmware
+ implementing the PSCI specification for CPU-centric power
+ management operations described in ARM document number ARM DEN
+ 0022A ("Power State Coordination Interface System Software on
+ ARM processors").
+
+config HZ_FIXED
+ int
+ default 128 if SOC_AT91RM9200
+ default 0
+
+choice
+ depends on HZ_FIXED = 0
+ prompt "Timer frequency"
+
+config HZ_100
+ bool "100 Hz"
+
+config HZ_200
+ bool "200 Hz"
+
+config HZ_250
+ bool "250 Hz"
+
+config HZ_300
+ bool "300 Hz"
+
+config HZ_500
+ bool "500 Hz"
+
+config HZ_1000
+ bool "1000 Hz"
+
+endchoice
+
+config HZ
+ int
+ default HZ_FIXED if HZ_FIXED != 0
+ default 100 if HZ_100
+ default 200 if HZ_200
+ default 250 if HZ_250
+ default 300 if HZ_300
+ default 500 if HZ_500
+ default 1000
+
+config SCHED_HRTICK
+ def_bool HIGH_RES_TIMERS
+
+config THUMB2_KERNEL
+ bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
+ depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
+ default y if CPU_THUMBONLY
+ select ARM_UNWIND
+ help
+ By enabling this option, the kernel will be compiled in
+ Thumb-2 mode.
+
+ If unsure, say N.
+
+config ARM_PATCH_IDIV
+ bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
+ depends on CPU_32v7
+ default y
+ help
+ The ARM compiler inserts calls to __aeabi_idiv() and
+ __aeabi_uidiv() when it needs to perform division on signed
+ and unsigned integers. Some v7 CPUs have support for the sdiv
+ and udiv instructions that can be used to implement those
+ functions.
+
+ Enabling this option allows the kernel to modify itself to
+ replace the first two instructions of these library functions
+ with the sdiv or udiv plus "bx lr" instructions when the CPU
+ it is running on supports them. Typically this will be faster
+ and less power intensive than running the original library
+ code to do integer division.
+
+config AEABI
+ bool "Use the ARM EABI to compile the kernel" if !CPU_V7 && \
+ !CPU_V7M && !CPU_V6 && !CPU_V6K && !CC_IS_CLANG
+ default CPU_V7 || CPU_V7M || CPU_V6 || CPU_V6K || CC_IS_CLANG
+ help
+ This option allows for the kernel to be compiled using the latest
+ ARM ABI (aka EABI). This is only useful if you are using a user
+ space environment that is also compiled with EABI.
+
+ Since there are major incompatibilities between the legacy ABI and
+ EABI, especially with regard to structure member alignment, this
+ option also changes the kernel syscall calling convention to
+ disambiguate both ABIs and allow for backward compatibility support
+ (selected with CONFIG_OABI_COMPAT).
+
+ To use this you need GCC version 4.0.0 or later.
+
+config OABI_COMPAT
+ bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
+ depends on AEABI && !THUMB2_KERNEL
+ help
+ This option preserves the old syscall interface along with the
+ new (ARM EABI) one. It also provides a compatibility layer to
+ intercept syscalls that have structure arguments which layout
+ in memory differs between the legacy ABI and the new ARM EABI
+ (only for non "thumb" binaries). This option adds a tiny
+ overhead to all syscalls and produces a slightly larger kernel.
+
+ The seccomp filter system will not be available when this is
+ selected, since there is no way yet to sensibly distinguish
+ between calling conventions during filtering.
+
+ If you know you'll be using only pure EABI user space then you
+ can say N here. If this option is not selected and you attempt
+ to execute a legacy ABI binary then the result will be
+ UNPREDICTABLE (in fact it can be predicted that it won't work
+ at all). If in doubt say N.
+
+config ARCH_SELECT_MEMORY_MODEL
+ def_bool y
+
+config ARCH_FLATMEM_ENABLE
+ def_bool !(ARCH_RPC || ARCH_SA1100)
+
+config ARCH_SPARSEMEM_ENABLE
+ def_bool !ARCH_FOOTBRIDGE
+ select SPARSEMEM_STATIC if SPARSEMEM
+
+config HIGHMEM
+ bool "High Memory Support"
+ depends on MMU
+ select KMAP_LOCAL
+ select KMAP_LOCAL_NON_LINEAR_PTE_ARRAY
+ help
+ The address space of ARM processors is only 4 Gigabytes large
+ and it has to accommodate user address space, kernel address
+ space as well as some memory mapped IO. That means that, if you
+ have a large amount of physical memory and/or IO, not all of the
+ memory can be "permanently mapped" by the kernel. The physical
+ memory that is not permanently mapped is called "high memory".
+
+ Depending on the selected kernel/user memory split, minimum
+ vmalloc space and actual amount of RAM, you may not need this
+ option which should result in a slightly faster kernel.
+
+ If unsure, say n.
+
+config HIGHPTE
+ bool "Allocate 2nd-level pagetables from highmem" if EXPERT
+ depends on HIGHMEM
+ default y
+ help
+ The VM uses one page of physical memory for each page table.
+ For systems with a lot of processes, this can use a lot of
+ precious low memory, eventually leading to low memory being
+ consumed by page tables. Setting this option will allow
+ user-space 2nd level page tables to reside in high memory.
+
+config CPU_SW_DOMAIN_PAN
+ bool "Enable use of CPU domains to implement privileged no-access"
+ depends on MMU && !ARM_LPAE
+ default y
+ help
+ Increase kernel security by ensuring that normal kernel accesses
+ are unable to access userspace addresses. This can help prevent
+ use-after-free bugs becoming an exploitable privilege escalation
+ by ensuring that magic values (such as LIST_POISON) will always
+ fault when dereferenced.
+
+ CPUs with low-vector mappings use a best-efforts implementation.
+ Their lower 1MB needs to remain accessible for the vectors, but
+ the remainder of userspace will become appropriately inaccessible.
+
+config HW_PERF_EVENTS
+ def_bool y
+ depends on ARM_PMU
+
+config ARM_MODULE_PLTS
+ bool "Use PLTs to allow module memory to spill over into vmalloc area"
+ depends on MODULES
+ select KASAN_VMALLOC if KASAN
+ default y
+ help
+ Allocate PLTs when loading modules so that jumps and calls whose
+ targets are too far away for their relative offsets to be encoded
+ in the instructions themselves can be bounced via veneers in the
+ module's PLT. This allows modules to be allocated in the generic
+ vmalloc area after the dedicated module memory area has been
+ exhausted. The modules will use slightly more memory, but after
+ rounding up to page size, the actual memory footprint is usually
+ the same.
+
+ Disabling this is usually safe for small single-platform
+ configurations. If unsure, say y.
+
+config ARCH_FORCE_MAX_ORDER
+ int "Order of maximal physically contiguous allocations"
+ default "11" if SOC_AM33XX
+ default "8" if SA1111
+ 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.
+
+ Don't change if unsure.
+
+config ALIGNMENT_TRAP
+ def_bool CPU_CP15_MMU
+ select HAVE_PROC_CPU if PROC_FS
+ help
+ ARM processors cannot fetch/store information which is not
+ naturally aligned on the bus, i.e., a 4 byte fetch must start at an
+ address divisible by 4. On 32-bit ARM processors, these non-aligned
+ fetch/store instructions will be emulated in software if you say
+ here, which has a severe performance impact. This is necessary for
+ correct operation of some network protocols. With an IP-only
+ configuration it is safe to say N, otherwise say Y.
+
+config UACCESS_WITH_MEMCPY
+ bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
+ depends on MMU
+ default y if CPU_FEROCEON
+ help
+ Implement faster copy_to_user and clear_user methods for CPU
+ cores where a 8-word STM instruction give significantly higher
+ memory write throughput than a sequence of individual 32bit stores.
+
+ A possible side effect is a slight increase in scheduling latency
+ between threads sharing the same address space if they invoke
+ such copy operations with large buffers.
+
+ However, if the CPU data cache is using a write-allocate mode,
+ this option is unlikely to provide any performance gain.
+
+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 XEN_DOM0
+ def_bool y
+ depends on XEN
+
+config XEN
+ bool "Xen guest support on ARM"
+ depends on ARM && AEABI && OF
+ depends on CPU_V7 && !CPU_V6
+ depends on !GENERIC_ATOMIC64
+ depends on MMU
+ select ARCH_DMA_ADDR_T_64BIT
+ select ARM_PSCI
+ select SWIOTLB
+ select SWIOTLB_XEN
+ select PARAVIRT
+ help
+ Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
+
+config CC_HAVE_STACKPROTECTOR_TLS
+ def_bool $(cc-option,-mtp=cp15 -mstack-protector-guard=tls -mstack-protector-guard-offset=0)
+
+config STACKPROTECTOR_PER_TASK
+ bool "Use a unique stack canary value for each task"
+ depends on STACKPROTECTOR && CURRENT_POINTER_IN_TPIDRURO && !XIP_DEFLATED_DATA
+ depends on GCC_PLUGINS || CC_HAVE_STACKPROTECTOR_TLS
+ select GCC_PLUGIN_ARM_SSP_PER_TASK if !CC_HAVE_STACKPROTECTOR_TLS
+ default y
+ help
+ Due to the fact that GCC uses an ordinary symbol reference from
+ which to load the value of the stack canary, this value can only
+ change at reboot time on SMP systems, and all tasks running in the
+ kernel's address space are forced to use the same canary value for
+ the entire duration that the system is up.
+
+ Enable this option to switch to a different method that uses a
+ different canary value for each task.
+
+endmenu
+
+menu "Boot options"
+
+config USE_OF
+ bool "Flattened Device Tree support"
+ select IRQ_DOMAIN
+ select OF
+ help
+ Include support for flattened device tree machine descriptions.
+
+config ARCH_WANT_FLAT_DTB_INSTALL
+ def_bool y
+
+config ATAGS
+ bool "Support for the traditional ATAGS boot data passing"
+ default y
+ help
+ This is the traditional way of passing data to the kernel at boot
+ time. If you are solely relying on the flattened device tree (or
+ the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
+ to remove ATAGS support from your kernel binary.
+
+config DEPRECATED_PARAM_STRUCT
+ bool "Provide old way to pass kernel parameters"
+ depends on ATAGS
+ help
+ This was deprecated in 2001 and announced to live on for 5 years.
+ Some old boot loaders still use this way.
+
+# Compressed boot loader in ROM. Yes, we really want to ask about
+# TEXT and BSS so we preserve their values in the config files.
+config ZBOOT_ROM_TEXT
+ hex "Compressed ROM boot loader base address"
+ default 0x0
+ help
+ The physical address at which the ROM-able zImage is to be
+ placed in the target. Platforms which normally make use of
+ ROM-able zImage formats normally set this to a suitable
+ value in their defconfig file.
+
+ If ZBOOT_ROM is not enabled, this has no effect.
+
+config ZBOOT_ROM_BSS
+ hex "Compressed ROM boot loader BSS address"
+ default 0x0
+ help
+ The base address of an area of read/write memory in the target
+ for the ROM-able zImage which must be available while the
+ decompressor is running. It must be large enough to hold the
+ entire decompressed kernel plus an additional 128 KiB.
+ Platforms which normally make use of ROM-able zImage formats
+ normally set this to a suitable value in their defconfig file.
+
+ If ZBOOT_ROM is not enabled, this has no effect.
+
+config ZBOOT_ROM
+ bool "Compressed boot loader in ROM/flash"
+ depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
+ depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
+ help
+ Say Y here if you intend to execute your compressed kernel image
+ (zImage) directly from ROM or flash. If unsure, say N.
+
+config ARM_APPENDED_DTB
+ bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
+ depends on OF
+ help
+ With this option, the boot code will look for a device tree binary
+ (DTB) appended to zImage
+ (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
+
+ This is meant as a backward compatibility convenience for those
+ systems with a bootloader that can't be upgraded to accommodate
+ the documented boot protocol using a device tree.
+
+ Beware that there is very little in terms of protection against
+ this option being confused by leftover garbage in memory that might
+ look like a DTB header after a reboot if no actual DTB is appended
+ to zImage. Do not leave this option active in a production kernel
+ if you don't intend to always append a DTB. Proper passing of the
+ location into r2 of a bootloader provided DTB is always preferable
+ to this option.
+
+config ARM_ATAG_DTB_COMPAT
+ bool "Supplement the appended DTB with traditional ATAG information"
+ depends on ARM_APPENDED_DTB
+ help
+ Some old bootloaders can't be updated to a DTB capable one, yet
+ they provide ATAGs with memory configuration, the ramdisk address,
+ the kernel cmdline string, etc. Such information is dynamically
+ provided by the bootloader and can't always be stored in a static
+ DTB. To allow a device tree enabled kernel to be used with such
+ bootloaders, this option allows zImage to extract the information
+ from the ATAG list and store it at run time into the appended DTB.
+
+choice
+ prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT
+ default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
+
+config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
+ bool "Use bootloader kernel arguments if available"
+ help
+ Uses the command-line options passed by the boot loader instead of
+ the device tree bootargs property. If the boot loader doesn't provide
+ any, the device tree bootargs property will be used.
+
+config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
+ bool "Extend with bootloader kernel arguments"
+ help
+ The command-line arguments provided by the boot loader will be
+ appended to the the device tree bootargs property.
+
+endchoice
+
+config CMDLINE
+ string "Default kernel command string"
+ default ""
+ help
+ On some architectures (e.g. CATS), there is currently no way
+ for the boot loader to pass arguments to the kernel. For these
+ architectures, you should supply some command-line options at build
+ time by entering them here. As a minimum, you should specify the
+ memory size and the root device (e.g., mem=64M root=/dev/nfs).
+
+choice
+ prompt "Kernel command line type" if CMDLINE != ""
+ default CMDLINE_FROM_BOOTLOADER
+
+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_EXTEND
+ bool "Extend bootloader kernel arguments"
+ help
+ The command-line arguments provided by the boot loader will be
+ appended to the default kernel command string.
+
+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 XIP_KERNEL
+ bool "Kernel Execute-In-Place from ROM"
+ depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
+ depends on !ARM_PATCH_IDIV && !ARM_PATCH_PHYS_VIRT && !SMP_ON_UP
+ help
+ Execute-In-Place allows the kernel to run from non-volatile storage
+ directly addressable by the CPU, such as NOR flash. This saves RAM
+ space since the text section of the kernel is not loaded from flash
+ to RAM. Read-write sections, such as the data section and stack,
+ are still copied to RAM. The XIP kernel is not compressed since
+ it has to run directly from flash, so it will take more space to
+ store it. The flash address used to link the kernel object files,
+ and for storing it, is configuration dependent. Therefore, if you
+ say Y here, you must know the proper physical address where to
+ store the kernel image depending on your own flash memory usage.
+
+ Also note that the make target becomes "make xipImage" rather than
+ "make zImage" or "make Image". The final kernel binary to put in
+ ROM memory will be arch/arm/boot/xipImage.
+
+ If unsure, say N.
+
+config XIP_PHYS_ADDR
+ hex "XIP Kernel Physical Location"
+ depends on XIP_KERNEL
+ default "0x00080000"
+ help
+ This is the physical address in your flash memory the kernel will
+ be linked for and stored to. This address is dependent on your
+ own flash usage.
+
+config XIP_DEFLATED_DATA
+ bool "Store kernel .data section compressed in ROM"
+ depends on XIP_KERNEL
+ select ZLIB_INFLATE
+ help
+ Before the kernel is actually executed, its .data section has to be
+ copied to RAM from ROM. This option allows for storing that data
+ in compressed form and decompressed to RAM rather than merely being
+ copied, saving some precious ROM space. A possible drawback is a
+ slightly longer boot delay.
+
+config ARCH_SUPPORTS_KEXEC
+ def_bool (!SMP || PM_SLEEP_SMP) && MMU
+
+config ATAGS_PROC
+ bool "Export atags in procfs"
+ depends on ATAGS && KEXEC
+ default y
+ help
+ Should the atags used to boot the kernel be exported in an "atags"
+ file in procfs. Useful with kexec.
+
+config ARCH_SUPPORTS_CRASH_DUMP
+ def_bool y
+
+config AUTO_ZRELADDR
+ bool "Auto calculation of the decompressed kernel image address" if !ARCH_MULTIPLATFORM
+ default !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
+ help
+ ZRELADDR is the physical address where the decompressed kernel
+ image will be placed. If AUTO_ZRELADDR is selected, the address
+ will be determined at run-time, either by masking the current IP
+ with 0xf8000000, or, if invalid, from the DTB passed in r2.
+ This assumes the zImage being placed in the first 128MB from
+ start of memory.
+
+config EFI_STUB
+ bool
+
+config EFI
+ bool "UEFI runtime support"
+ depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
+ select UCS2_STRING
+ select EFI_PARAMS_FROM_FDT
+ select EFI_STUB
+ select EFI_GENERIC_STUB
+ select EFI_RUNTIME_WRAPPERS
+ 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 for kernels that may run 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.
+
+ NOTE: This does *NOT* enable or encourage the use of DMI quirks,
+ i.e., the the practice of identifying the platform via DMI to
+ decide whether certain workarounds for buggy hardware and/or
+ firmware need to be enabled. This would require the DMI subsystem
+ to be enabled much earlier than we do on ARM, which is non-trivial.
+
+endmenu
+
+menu "CPU Power Management"
+
+source "drivers/cpufreq/Kconfig"
+
+source "drivers/cpuidle/Kconfig"
+
+endmenu
+
+menu "Floating point emulation"
+
+comment "At least one emulation must be selected"
+
+config FPE_NWFPE
+ bool "NWFPE math emulation"
+ depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
+ help
+ Say Y to include the NWFPE floating point emulator in the kernel.
+ This is necessary to run most binaries. Linux does not currently
+ support floating point hardware so you need to say Y here even if
+ your machine has an FPA or floating point co-processor podule.
+
+ You may say N here if you are going to load the Acorn FPEmulator
+ early in the bootup.
+
+config FPE_NWFPE_XP
+ bool "Support extended precision"
+ depends on FPE_NWFPE
+ help
+ Say Y to include 80-bit support in the kernel floating-point
+ emulator. Otherwise, only 32 and 64-bit support is compiled in.
+ Note that gcc does not generate 80-bit operations by default,
+ so in most cases this option only enlarges the size of the
+ floating point emulator without any good reason.
+
+ You almost surely want to say N here.
+
+config FPE_FASTFPE
+ bool "FastFPE math emulation (EXPERIMENTAL)"
+ depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
+ help
+ Say Y here to include the FAST floating point emulator in the kernel.
+ This is an experimental much faster emulator which now also has full
+ precision for the mantissa. It does not support any exceptions.
+ It is very simple, and approximately 3-6 times faster than NWFPE.
+
+ It should be sufficient for most programs. It may be not suitable
+ for scientific calculations, but you have to check this for yourself.
+ If you do not feel you need a faster FP emulation you should better
+ choose NWFPE.
+
+config VFP
+ bool "VFP-format floating point maths"
+ depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
+ help
+ Say Y to include VFP support code in the kernel. This is needed
+ if your hardware includes a VFP unit.
+
+ Please see <file:Documentation/arch/arm/vfp/release-notes.rst> for
+ release notes and additional status information.
+
+ Say N if your target does not have VFP hardware.
+
+config VFPv3
+ bool
+ depends on VFP
+ default y if CPU_V7
+
+config NEON
+ bool "Advanced SIMD (NEON) Extension support"
+ depends on VFPv3 && CPU_V7
+ help
+ Say Y to include support code for NEON, the ARMv7 Advanced SIMD
+ Extension.
+
+config KERNEL_MODE_NEON
+ bool "Support for NEON in kernel mode"
+ depends on NEON && AEABI
+ help
+ Say Y to include support for NEON in kernel mode.
+
+endmenu
+
+menu "Power management options"
+
+source "kernel/power/Kconfig"
+
+config ARCH_SUSPEND_POSSIBLE
+ depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
+ CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
+ def_bool y
+
+config ARM_CPU_SUSPEND
+ def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW
+ depends on ARCH_SUSPEND_POSSIBLE
+
+config ARCH_HIBERNATION_POSSIBLE
+ bool
+ depends on MMU
+ default y if ARCH_SUSPEND_POSSIBLE
+
+endmenu
+
+source "arch/arm/Kconfig.assembler"