linux/arch/s390/Kconfig
Linus Torvalds 7a932e5702 asm-generic: cross-architecture timer cleanup
This cleans up two ancient timer features that were never completed in
 the past, CONFIG_GENERIC_CLOCKEVENTS and CONFIG_ARCH_USES_GETTIMEOFFSET.
 
 There was only one user left for the ARCH_USES_GETTIMEOFFSET variant
 of clocksource implementations, the ARM EBSA110 platform. Rather than
 changing to use modern timekeeping, we remove the platform entirely as
 Russell no longer uses his machine and nobody else seems to have one
 any more.
 
 The conditional code for using arch_gettimeoffset() is removed as
 a result.
 
 For CONFIG_GENERIC_CLOCKEVENTS, there are still a couple of platforms
 not using clockevent drivers: parisc, ia64, most of m68k, and one
 Arm platform. These all do timer ticks slighly differently, and this
 gets cleaned up to the point they at least all call the same helper
 function. Instead of most platforms using 'select GENERIC_CLOCKEVENTS'
 in Kconfig, the polarity is now reversed, with the few remaining ones
 selecting LEGACY_TIMER_TICK instead.
 
 Signed-off-by: Arnd Bergmann <arnd@arndb.de>
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEo6/YBQwIrVS28WGKmmx57+YAGNkFAl/Y1v8ACgkQmmx57+YA
 GNmCvQ/9EDlgCt92r8SB+LGafDtgB8TUQZeIrs9S2mByzdxwnw0lxObIXFCnhQgh
 RpG3dR+ONRDnC5eI149B377JOEFMZWe2+BtYHUHkFARtUEWatslQcz7yAGvVRK/l
 TS/qReb6piKltlzuanF1bMZbjy2OhlaDRcm+OlC3y5mALR33M4emb+rJ6cSdfk3K
 v1iZhrxtfQT77ztesh/oPkPiyQ6kNcz7SfpyYOb6f5VLlml2BZ7YwBSVyGY7urHk
 RL3XqOUP4KKlMEAI8w0E2nvft6Fk+luziBhrMYWK0GvbmI1OESENuX/c6tgT2OQ1
 DRaVHvcPG/EAY8adOKxxVyHhEJDSoz5GJV/EtjlOegsJk6RomczR1uuiT3Kvm7Ah
 PktMKv4xQht1E15KPSKbOvNIEP18w2s5z6gw+jVDv8pw42pVEQManm1D+BICqrhl
 fcpw6T1drf9UxAjwX4+zXtmNs+a+mqiFG8puU4VVgT4GpQ8umHvunXz2WUjZO0jc
 3m8ErJHBvtJwW5TOHGyXnjl9SkwPzHOfF6IcXTYWEDU4/gQIK9TwUvCjLc0lE27t
 FMCV2ds7/K1CXwRgpa5IrefSkb8yOXSbRZ56NqqF7Ekxw4J5bYRSaY7jb+qD/e+3
 5O1y+iPxFrpH+16hSahvzrtcdFNbLQvBBuRtEQOYuHLt2UJrNoU=
 =QpNs
 -----END PGP SIGNATURE-----

Merge tag 'asm-generic-timers-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

Pull asm-generic cross-architecture timer cleanup from Arnd Bergmann:
 "This cleans up two ancient timer features that were never completed in
  the past, CONFIG_GENERIC_CLOCKEVENTS and CONFIG_ARCH_USES_GETTIMEOFFSET.

  There was only one user left for the ARCH_USES_GETTIMEOFFSET variant
  of clocksource implementations, the ARM EBSA110 platform. Rather than
  changing to use modern timekeeping, we remove the platform entirely as
  Russell no longer uses his machine and nobody else seems to have one
  any more.

  The conditional code for using arch_gettimeoffset() is removed as a
  result.

  For CONFIG_GENERIC_CLOCKEVENTS, there are still a couple of platforms
  not using clockevent drivers: parisc, ia64, most of m68k, and one Arm
  platform. These all do timer ticks slighly differently, and this gets
  cleaned up to the point they at least all call the same helper
  function.

  Instead of most platforms using 'select GENERIC_CLOCKEVENTS' in
  Kconfig, the polarity is now reversed, with the few remaining ones
  selecting LEGACY_TIMER_TICK instead"

* tag 'asm-generic-timers-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  timekeeping: default GENERIC_CLOCKEVENTS to enabled
  timekeeping: remove xtime_update
  m68k: remove timer_interrupt() function
  m68k: change remaining timers to legacy_timer_tick
  m68k: m68328: use legacy_timer_tick()
  m68k: sun3/sun3c: use legacy_timer_tick
  m68k: split heartbeat out of timer function
  m68k: coldfire: use legacy_timer_tick()
  parisc: use legacy_timer_tick
  ARM: rpc: use legacy_timer_tick
  ia64: convert to legacy_timer_tick
  timekeeping: add CONFIG_LEGACY_TIMER_TICK
  timekeeping: remove arch_gettimeoffset
  net: remove am79c961a driver
  ARM: remove ebsa110 platform
2020-12-16 00:07:17 -08:00

954 lines
26 KiB
Plaintext

# SPDX-License-Identifier: GPL-2.0
config MMU
def_bool y
config ZONE_DMA
def_bool y
config CPU_BIG_ENDIAN
def_bool y
config LOCKDEP_SUPPORT
def_bool y
config STACKTRACE_SUPPORT
def_bool y
config ARCH_HAS_ILOG2_U32
def_bool n
config ARCH_HAS_ILOG2_U64
def_bool n
config GENERIC_HWEIGHT
def_bool y
config GENERIC_BUG
def_bool y if BUG
config GENERIC_BUG_RELATIVE_POINTERS
def_bool y
config GENERIC_LOCKBREAK
def_bool y if PREEMPTION
config PGSTE
def_bool y if KVM
config AUDIT_ARCH
def_bool y
config NO_IOPORT_MAP
def_bool y
config PCI_QUIRKS
def_bool n
config ARCH_SUPPORTS_UPROBES
def_bool y
config KASAN_SHADOW_OFFSET
hex
depends on KASAN
default 0x18000000000000
config S390
def_bool y
select ARCH_BINFMT_ELF_STATE
select ARCH_HAS_DEBUG_VM_PGTABLE
select ARCH_HAS_DEBUG_WX
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_FORTIFY_SOURCE
select ARCH_HAS_GCOV_PROFILE_ALL
select ARCH_HAS_GIGANTIC_PAGE
select ARCH_HAS_KCOV
select ARCH_HAS_MEM_ENCRYPT
select ARCH_HAS_PTE_SPECIAL
select ARCH_HAS_SET_MEMORY
select ARCH_HAS_STRICT_KERNEL_RWX
select ARCH_HAS_STRICT_MODULE_RWX
select ARCH_HAS_SYSCALL_WRAPPER
select ARCH_HAS_UBSAN_SANITIZE_ALL
select ARCH_HAS_VDSO_DATA
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select ARCH_INLINE_READ_LOCK
select ARCH_INLINE_READ_LOCK_BH
select ARCH_INLINE_READ_LOCK_IRQ
select ARCH_INLINE_READ_LOCK_IRQSAVE
select ARCH_INLINE_READ_TRYLOCK
select ARCH_INLINE_READ_UNLOCK
select ARCH_INLINE_READ_UNLOCK_BH
select ARCH_INLINE_READ_UNLOCK_IRQ
select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
select ARCH_INLINE_SPIN_LOCK
select ARCH_INLINE_SPIN_LOCK_BH
select ARCH_INLINE_SPIN_LOCK_IRQ
select ARCH_INLINE_SPIN_LOCK_IRQSAVE
select ARCH_INLINE_SPIN_TRYLOCK
select ARCH_INLINE_SPIN_TRYLOCK_BH
select ARCH_INLINE_SPIN_UNLOCK
select ARCH_INLINE_SPIN_UNLOCK_BH
select ARCH_INLINE_SPIN_UNLOCK_IRQ
select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
select ARCH_INLINE_WRITE_LOCK
select ARCH_INLINE_WRITE_LOCK_BH
select ARCH_INLINE_WRITE_LOCK_IRQ
select ARCH_INLINE_WRITE_LOCK_IRQSAVE
select ARCH_INLINE_WRITE_TRYLOCK
select ARCH_INLINE_WRITE_UNLOCK
select ARCH_INLINE_WRITE_UNLOCK_BH
select ARCH_INLINE_WRITE_UNLOCK_IRQ
select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
select ARCH_STACKWALK
select ARCH_SUPPORTS_ATOMIC_RMW
select ARCH_SUPPORTS_DEBUG_PAGEALLOC
select ARCH_SUPPORTS_NUMA_BALANCING
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_CMPXCHG_LOCKREF
select ARCH_WANTS_DYNAMIC_TASK_STRUCT
select ARCH_WANT_DEFAULT_BPF_JIT
select ARCH_WANT_IPC_PARSE_VERSION
select BUILDTIME_TABLE_SORT
select CLONE_BACKWARDS2
select DMA_OPS if PCI
select DYNAMIC_FTRACE if FUNCTION_TRACER
select GENERIC_CPU_AUTOPROBE
select GENERIC_CPU_VULNERABILITIES
select GENERIC_FIND_FIRST_BIT
select GENERIC_GETTIMEOFDAY
select GENERIC_PTDUMP
select GENERIC_SMP_IDLE_THREAD
select GENERIC_TIME_VSYSCALL
select HAVE_ALIGNED_STRUCT_PAGE if SLUB
select HAVE_ARCH_AUDITSYSCALL
select HAVE_ARCH_JUMP_LABEL
select HAVE_ARCH_JUMP_LABEL_RELATIVE
select HAVE_ARCH_KASAN
select HAVE_ARCH_KASAN_VMALLOC
select CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES
select HAVE_ARCH_SECCOMP_FILTER
select HAVE_ARCH_SOFT_DIRTY
select HAVE_ARCH_TRACEHOOK
select HAVE_ARCH_TRANSPARENT_HUGEPAGE
select HAVE_ARCH_VMAP_STACK
select HAVE_ASM_MODVERSIONS
select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
select HAVE_CMPXCHG_DOUBLE
select HAVE_CMPXCHG_LOCAL
select HAVE_DEBUG_KMEMLEAK
select HAVE_DMA_CONTIGUOUS
select HAVE_DYNAMIC_FTRACE
select HAVE_DYNAMIC_FTRACE_WITH_REGS
select HAVE_FAST_GUP
select HAVE_EFFICIENT_UNALIGNED_ACCESS
select HAVE_FENTRY
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_FUNCTION_ERROR_INJECTION
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_TRACER
select HAVE_FUTEX_CMPXCHG if FUTEX
select HAVE_GCC_PLUGINS
select HAVE_GENERIC_VDSO
select HAVE_KERNEL_BZIP2
select HAVE_KERNEL_GZIP
select HAVE_KERNEL_LZ4
select HAVE_KERNEL_LZMA
select HAVE_KERNEL_LZO
select HAVE_KERNEL_UNCOMPRESSED
select HAVE_KERNEL_XZ
select HAVE_KPROBES
select HAVE_KPROBES_ON_FTRACE
select HAVE_KRETPROBES
select HAVE_KVM
select HAVE_LIVEPATCH
select HAVE_PERF_REGS
select HAVE_PERF_USER_STACK_DUMP
select HAVE_MEMBLOCK_PHYS_MAP
select MMU_GATHER_NO_GATHER
select HAVE_MOD_ARCH_SPECIFIC
select HAVE_NOP_MCOUNT
select HAVE_OPROFILE
select HAVE_PCI
select HAVE_PERF_EVENTS
select MMU_GATHER_RCU_TABLE_FREE
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_RELIABLE_STACKTRACE
select HAVE_RSEQ
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_VIRT_CPU_ACCOUNTING
select HAVE_VIRT_CPU_ACCOUNTING_IDLE
select IOMMU_HELPER if PCI
select IOMMU_SUPPORT if PCI
select MODULES_USE_ELF_RELA
select NEED_DMA_MAP_STATE if PCI
select NEED_SG_DMA_LENGTH if PCI
select OLD_SIGACTION
select OLD_SIGSUSPEND3
select PCI_DOMAINS if PCI
select PCI_MSI if PCI
select PCI_MSI_ARCH_FALLBACKS if PCI_MSI
select SPARSE_IRQ
select SYSCTL_EXCEPTION_TRACE
select THREAD_INFO_IN_TASK
select TTY
select VIRT_CPU_ACCOUNTING
select ARCH_HAS_SCALED_CPUTIME
select HAVE_NMI
select ARCH_HAS_FORCE_DMA_UNENCRYPTED
select SWIOTLB
select GENERIC_ALLOCATOR
imply IMA_SECURE_AND_OR_TRUSTED_BOOT
config SCHED_OMIT_FRAME_POINTER
def_bool y
config PGTABLE_LEVELS
int
default 5
source "kernel/livepatch/Kconfig"
menu "Processor type and features"
config HAVE_MARCH_Z900_FEATURES
def_bool n
config HAVE_MARCH_Z990_FEATURES
def_bool n
select HAVE_MARCH_Z900_FEATURES
config HAVE_MARCH_Z9_109_FEATURES
def_bool n
select HAVE_MARCH_Z990_FEATURES
config HAVE_MARCH_Z10_FEATURES
def_bool n
select HAVE_MARCH_Z9_109_FEATURES
config HAVE_MARCH_Z196_FEATURES
def_bool n
select HAVE_MARCH_Z10_FEATURES
config HAVE_MARCH_ZEC12_FEATURES
def_bool n
select HAVE_MARCH_Z196_FEATURES
config HAVE_MARCH_Z13_FEATURES
def_bool n
select HAVE_MARCH_ZEC12_FEATURES
config HAVE_MARCH_Z14_FEATURES
def_bool n
select HAVE_MARCH_Z13_FEATURES
config HAVE_MARCH_Z15_FEATURES
def_bool n
select HAVE_MARCH_Z14_FEATURES
choice
prompt "Processor type"
default MARCH_Z196
config MARCH_Z900
bool "IBM zSeries model z800 and z900"
select HAVE_MARCH_Z900_FEATURES
depends on $(cc-option,-march=z900)
help
Select this to enable optimizations for model z800/z900 (2064 and
2066 series). This will enable some optimizations that are not
available on older ESA/390 (31 Bit) only CPUs.
config MARCH_Z990
bool "IBM zSeries model z890 and z990"
select HAVE_MARCH_Z990_FEATURES
depends on $(cc-option,-march=z990)
help
Select this to enable optimizations for model z890/z990 (2084 and
2086 series). The kernel will be slightly faster but will not work
on older machines.
config MARCH_Z9_109
bool "IBM System z9"
select HAVE_MARCH_Z9_109_FEATURES
depends on $(cc-option,-march=z9-109)
help
Select this to enable optimizations for IBM System z9 (2094 and
2096 series). The kernel will be slightly faster but will not work
on older machines.
config MARCH_Z10
bool "IBM System z10"
select HAVE_MARCH_Z10_FEATURES
depends on $(cc-option,-march=z10)
help
Select this to enable optimizations for IBM System z10 (2097 and
2098 series). The kernel will be slightly faster but will not work
on older machines.
config MARCH_Z196
bool "IBM zEnterprise 114 and 196"
select HAVE_MARCH_Z196_FEATURES
depends on $(cc-option,-march=z196)
help
Select this to enable optimizations for IBM zEnterprise 114 and 196
(2818 and 2817 series). The kernel will be slightly faster but will
not work on older machines.
config MARCH_ZEC12
bool "IBM zBC12 and zEC12"
select HAVE_MARCH_ZEC12_FEATURES
depends on $(cc-option,-march=zEC12)
help
Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
2827 series). The kernel will be slightly faster but will not work on
older machines.
config MARCH_Z13
bool "IBM z13s and z13"
select HAVE_MARCH_Z13_FEATURES
depends on $(cc-option,-march=z13)
help
Select this to enable optimizations for IBM z13s and z13 (2965 and
2964 series). The kernel will be slightly faster but will not work on
older machines.
config MARCH_Z14
bool "IBM z14 ZR1 and z14"
select HAVE_MARCH_Z14_FEATURES
depends on $(cc-option,-march=z14)
help
Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
and 3906 series). The kernel will be slightly faster but will not
work on older machines.
config MARCH_Z15
bool "IBM z15"
select HAVE_MARCH_Z15_FEATURES
depends on $(cc-option,-march=z15)
help
Select this to enable optimizations for IBM z15 (8562
and 8561 series). The kernel will be slightly faster but will not
work on older machines.
endchoice
config MARCH_Z900_TUNE
def_bool TUNE_Z900 || MARCH_Z900 && TUNE_DEFAULT
config MARCH_Z990_TUNE
def_bool TUNE_Z990 || MARCH_Z990 && TUNE_DEFAULT
config MARCH_Z9_109_TUNE
def_bool TUNE_Z9_109 || MARCH_Z9_109 && TUNE_DEFAULT
config MARCH_Z10_TUNE
def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
config MARCH_Z196_TUNE
def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
config MARCH_ZEC12_TUNE
def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
config MARCH_Z13_TUNE
def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
config MARCH_Z14_TUNE
def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
config MARCH_Z15_TUNE
def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT
choice
prompt "Tune code generation"
default TUNE_DEFAULT
help
Cause the compiler to tune (-mtune) the generated code for a machine.
This will make the code run faster on the selected machine but
somewhat slower on other machines.
This option only changes how the compiler emits instructions, not the
selection of instructions itself, so the resulting kernel will run on
all other machines.
config TUNE_DEFAULT
bool "Default"
help
Tune the generated code for the target processor for which the kernel
will be compiled.
config TUNE_Z900
bool "IBM zSeries model z800 and z900"
depends on $(cc-option,-mtune=z900)
config TUNE_Z990
bool "IBM zSeries model z890 and z990"
depends on $(cc-option,-mtune=z990)
config TUNE_Z9_109
bool "IBM System z9"
depends on $(cc-option,-mtune=z9-109)
config TUNE_Z10
bool "IBM System z10"
depends on $(cc-option,-mtune=z10)
config TUNE_Z196
bool "IBM zEnterprise 114 and 196"
depends on $(cc-option,-mtune=z196)
config TUNE_ZEC12
bool "IBM zBC12 and zEC12"
depends on $(cc-option,-mtune=zEC12)
config TUNE_Z13
bool "IBM z13s and z13"
depends on $(cc-option,-mtune=z13)
config TUNE_Z14
bool "IBM z14 ZR1 and z14"
depends on $(cc-option,-mtune=z14)
config TUNE_Z15
bool "IBM z15"
depends on $(cc-option,-mtune=z15)
endchoice
config 64BIT
def_bool y
config COMPAT
def_bool y
prompt "Kernel support for 31 bit emulation"
select COMPAT_BINFMT_ELF if BINFMT_ELF
select ARCH_WANT_OLD_COMPAT_IPC
select COMPAT_OLD_SIGACTION
select HAVE_UID16
depends on MULTIUSER
help
Select this option if you want to enable your system kernel to
handle system-calls from ELF binaries for 31 bit ESA. This option
(and some other stuff like libraries and such) is needed for
executing 31 bit applications. It is safe to say "Y".
config SYSVIPC_COMPAT
def_bool y if COMPAT && SYSVIPC
config SMP
def_bool y
config NR_CPUS
int "Maximum number of CPUs (2-512)"
range 2 512
default "64"
help
This allows you to specify the maximum number of CPUs which this
kernel will support. The maximum supported value is 512 and the
minimum value which makes sense is 2.
This is purely to save memory - each supported CPU adds
approximately sixteen kilobytes to the kernel image.
config HOTPLUG_CPU
def_bool y
config NUMA
bool "NUMA support"
depends on SCHED_TOPOLOGY
default n
help
Enable NUMA support
This option adds NUMA support to the kernel.
config NODES_SHIFT
int
depends on NEED_MULTIPLE_NODES
default "1"
config SCHED_SMT
def_bool n
config SCHED_MC
def_bool n
config SCHED_BOOK
def_bool n
config SCHED_DRAWER
def_bool n
config SCHED_TOPOLOGY
def_bool y
prompt "Topology scheduler support"
select SCHED_SMT
select SCHED_MC
select SCHED_BOOK
select SCHED_DRAWER
help
Topology scheduler support improves the CPU scheduler's decision
making when dealing with machines that have multi-threading,
multiple cores or multiple books.
source "kernel/Kconfig.hz"
config KEXEC
def_bool y
select KEXEC_CORE
config KEXEC_FILE
bool "kexec file based system call"
select KEXEC_CORE
select BUILD_BIN2C
depends on CRYPTO
depends on CRYPTO_SHA256
depends on CRYPTO_SHA256_S390
help
Enable the kexec file based system call. In contrast to the normal
kexec system call this system call takes file descriptors for the
kernel and initramfs as arguments.
config ARCH_HAS_KEXEC_PURGATORY
def_bool y
depends on KEXEC_FILE
config KEXEC_SIG
bool "Verify kernel signature during kexec_file_load() syscall"
depends on KEXEC_FILE && MODULE_SIG_FORMAT
help
This option makes kernel signature verification mandatory for
the kexec_file_load() syscall.
In addition to that option, you need to enable signature
verification for the corresponding kernel image type being
loaded in order for this to work.
config ARCH_RANDOM
def_bool y
prompt "s390 architectural random number generation API"
help
Enable the s390 architectural random number generation API
to provide random data for all consumers within the Linux
kernel.
When enabled the arch_random_* functions declared in linux/random.h
are implemented. The implementation is based on the s390 CPACF
instruction subfunction TRNG which provides a real true random
number generator.
If unsure, say Y.
config KERNEL_NOBP
def_bool n
prompt "Enable modified branch prediction for the kernel by default"
help
If this option is selected the kernel will switch to a modified
branch prediction mode if the firmware interface is available.
The modified branch prediction mode improves the behaviour in
regard to speculative execution.
With the option enabled the kernel parameter "nobp=0" or "nospec"
can be used to run the kernel in the normal branch prediction mode.
With the option disabled the modified branch prediction mode is
enabled with the "nobp=1" kernel parameter.
If unsure, say N.
config EXPOLINE
def_bool n
prompt "Avoid speculative indirect branches in the kernel"
help
Compile the kernel with the expoline compiler options to guard
against kernel-to-user data leaks by avoiding speculative indirect
branches.
Requires a compiler with -mindirect-branch=thunk support for full
protection. The kernel may run slower.
If unsure, say N.
choice
prompt "Expoline default"
depends on EXPOLINE
default EXPOLINE_FULL
config EXPOLINE_OFF
bool "spectre_v2=off"
config EXPOLINE_AUTO
bool "spectre_v2=auto"
config EXPOLINE_FULL
bool "spectre_v2=on"
endchoice
config RELOCATABLE
bool "Build a relocatable kernel"
select MODULE_REL_CRCS if MODVERSIONS
default y
help
This builds a kernel image that retains relocation information
so it can be loaded at an arbitrary address.
The kernel is linked as a position-independent executable (PIE)
and contains dynamic relocations which are processed early in the
bootup process.
The relocations make the kernel image about 15% larger (compressed
10%), but are discarded at runtime.
config RANDOMIZE_BASE
bool "Randomize the address of the kernel image (KASLR)"
depends on RELOCATABLE
default y
help
In support of Kernel Address Space Layout Randomization (KASLR),
this randomizes the 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.
endmenu
menu "Memory setup"
config ARCH_SPARSEMEM_ENABLE
def_bool y
select SPARSEMEM_VMEMMAP_ENABLE
select SPARSEMEM_VMEMMAP
config ARCH_SPARSEMEM_DEFAULT
def_bool y
config ARCH_ENABLE_MEMORY_HOTPLUG
def_bool y if SPARSEMEM
config ARCH_ENABLE_MEMORY_HOTREMOVE
def_bool y
config ARCH_ENABLE_SPLIT_PMD_PTLOCK
def_bool y
config MAX_PHYSMEM_BITS
int "Maximum size of supported physical memory in bits (42-53)"
range 42 53
default "46"
help
This option specifies the maximum supported size of physical memory
in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
Increasing the number of bits also increases the kernel image size.
By default 46 bits (64TB) are supported.
config PACK_STACK
def_bool y
prompt "Pack kernel stack"
help
This option enables the compiler option -mkernel-backchain if it
is available. If the option is available the compiler supports
the new stack layout which dramatically reduces the minimum stack
frame size. With an old compiler a non-leaf function needs a
minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
-mkernel-backchain the minimum size drops to 16 byte on 31 bit
and 24 byte on 64 bit.
Say Y if you are unsure.
config CHECK_STACK
def_bool y
depends on !VMAP_STACK
prompt "Detect kernel stack overflow"
help
This option enables the compiler option -mstack-guard and
-mstack-size if they are available. If the compiler supports them
it will emit additional code to each function prolog to trigger
an illegal operation if the kernel stack is about to overflow.
Say N if you are unsure.
config STACK_GUARD
int "Size of the guard area (128-1024)"
range 128 1024
depends on CHECK_STACK
default "256"
help
This allows you to specify the size of the guard area at the lower
end of the kernel stack. If the kernel stack points into the guard
area on function entry an illegal operation is triggered. The size
needs to be a power of 2. Please keep in mind that the size of an
interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
The minimum size for the stack guard should be 256 for 31 bit and
512 for 64 bit.
config WARN_DYNAMIC_STACK
def_bool n
prompt "Emit compiler warnings for function with dynamic stack usage"
help
This option enables the compiler option -mwarn-dynamicstack. If the
compiler supports this options generates warnings for functions
that dynamically allocate stack space using alloca.
Say N if you are unsure.
endmenu
menu "I/O subsystem"
config QDIO
def_tristate y
prompt "QDIO support"
help
This driver provides the Queued Direct I/O base support for
IBM System z.
To compile this driver as a module, choose M here: the
module will be called qdio.
If unsure, say Y.
if PCI
config PCI_NR_FUNCTIONS
int "Maximum number of PCI functions (1-4096)"
range 1 4096
default "512"
help
This allows you to specify the maximum number of PCI functions which
this kernel will support.
endif # PCI
config HAS_IOMEM
def_bool PCI
config CHSC_SCH
def_tristate m
prompt "Support for CHSC subchannels"
help
This driver allows usage of CHSC subchannels. A CHSC subchannel
is usually present on LPAR only.
The driver creates a device /dev/chsc, which may be used to
obtain I/O configuration information about the machine and
to issue asynchronous chsc commands (DANGEROUS).
You will usually only want to use this interface on a special
LPAR designated for system management.
To compile this driver as a module, choose M here: the
module will be called chsc_sch.
If unsure, say N.
config SCM_BUS
def_bool y
prompt "SCM bus driver"
help
Bus driver for Storage Class Memory.
config EADM_SCH
def_tristate m
prompt "Support for EADM subchannels"
depends on SCM_BUS
help
This driver allows usage of EADM subchannels. EADM subchannels act
as a communication vehicle for SCM increments.
To compile this driver as a module, choose M here: the
module will be called eadm_sch.
config VFIO_CCW
def_tristate n
prompt "Support for VFIO-CCW subchannels"
depends on S390_CCW_IOMMU && VFIO_MDEV
help
This driver allows usage of I/O subchannels via VFIO-CCW.
To compile this driver as a module, choose M here: the
module will be called vfio_ccw.
config VFIO_AP
def_tristate n
prompt "VFIO support for AP devices"
depends on S390_AP_IOMMU && VFIO_MDEV_DEVICE && KVM
depends on ZCRYPT
help
This driver grants access to Adjunct Processor (AP) devices
via the VFIO mediated device interface.
To compile this driver as a module, choose M here: the module
will be called vfio_ap.
endmenu
menu "Dump support"
config CRASH_DUMP
bool "kernel crash dumps"
select KEXEC
help
Generate crash dump after being started by kexec.
Crash dump kernels are loaded in the main kernel with kexec-tools
into a specially reserved region and then later executed after
a crash by kdump/kexec.
Refer to <file:Documentation/s390/zfcpdump.rst> for more details on this.
This option also enables s390 zfcpdump.
See also <file:Documentation/s390/zfcpdump.rst>
endmenu
config CCW
def_bool y
config HAVE_PNETID
tristate
default (SMC || CCWGROUP)
menu "Virtualization"
config PROTECTED_VIRTUALIZATION_GUEST
def_bool n
prompt "Protected virtualization guest support"
select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
help
Select this option, if you want to be able to run this
kernel as a protected virtualization KVM guest.
Protected virtualization capable machines have a mini hypervisor
located at machine level (an ultravisor). With help of the
Ultravisor, KVM will be able to run "protected" VMs, special
VMs whose memory and management data are unavailable to KVM.
config PFAULT
def_bool y
prompt "Pseudo page fault support"
help
Select this option, if you want to use PFAULT pseudo page fault
handling under VM. If running native or in LPAR, this option
has no effect. If your VM does not support PFAULT, PAGEEX
pseudo page fault handling will be used.
Note that VM 4.2 supports PFAULT but has a bug in its
implementation that causes some problems.
Everybody who wants to run Linux under VM != VM4.2 should select
this option.
config CMM
def_tristate n
prompt "Cooperative memory management"
help
Select this option, if you want to enable the kernel interface
to reduce the memory size of the system. This is accomplished
by allocating pages of memory and put them "on hold". This only
makes sense for a system running under VM where the unused pages
will be reused by VM for other guest systems. The interface
allows an external monitor to balance memory of many systems.
Everybody who wants to run Linux under VM should select this
option.
config CMM_IUCV
def_bool y
prompt "IUCV special message interface to cooperative memory management"
depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
help
Select this option to enable the special message interface to
the cooperative memory management.
config APPLDATA_BASE
def_bool n
prompt "Linux - VM Monitor Stream, base infrastructure"
depends on PROC_FS
help
This provides a kernel interface for creating and updating z/VM APPLDATA
monitor records. The monitor records are updated at certain time
intervals, once the timer is started.
Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
i.e. enables or disables monitoring on the Linux side.
A custom interval value (in seconds) can be written to
/proc/appldata/interval.
Defaults are 60 seconds interval and timer off.
The /proc entries can also be read from, showing the current settings.
config APPLDATA_MEM
def_tristate m
prompt "Monitor memory management statistics"
depends on APPLDATA_BASE && VM_EVENT_COUNTERS
help
This provides memory management related data to the Linux - VM Monitor
Stream, like paging/swapping rate, memory utilisation, etc.
Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
APPLDATA monitor record, i.e. enables or disables monitoring this record
on the z/VM side.
Default is disabled.
The /proc entry can also be read from, showing the current settings.
This can also be compiled as a module, which will be called
appldata_mem.o.
config APPLDATA_OS
def_tristate m
prompt "Monitor OS statistics"
depends on APPLDATA_BASE
help
This provides OS related data to the Linux - VM Monitor Stream, like
CPU utilisation, etc.
Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
APPLDATA monitor record, i.e. enables or disables monitoring this record
on the z/VM side.
Default is disabled.
This can also be compiled as a module, which will be called
appldata_os.o.
config APPLDATA_NET_SUM
def_tristate m
prompt "Monitor overall network statistics"
depends on APPLDATA_BASE && NET
help
This provides network related data to the Linux - VM Monitor Stream,
currently there is only a total sum of network I/O statistics, no
per-interface data.
Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
APPLDATA monitor record, i.e. enables or disables monitoring this record
on the z/VM side.
Default is disabled.
This can also be compiled as a module, which will be called
appldata_net_sum.o.
config S390_HYPFS_FS
def_bool y
prompt "s390 hypervisor file system support"
select SYS_HYPERVISOR
help
This is a virtual file system intended to provide accounting
information in an s390 hypervisor environment.
source "arch/s390/kvm/Kconfig"
config S390_GUEST
def_bool y
prompt "s390 support for virtio devices"
select TTY
select VIRTUALIZATION
select VIRTIO
help
Enabling this option adds support for virtio based paravirtual device
drivers on s390.
Select this option if you want to run the kernel as a guest under
the KVM hypervisor.
endmenu
menu "Selftests"
config S390_UNWIND_SELFTEST
def_tristate n
prompt "Test unwind functions"
help
This option enables s390 specific stack unwinder testing kernel
module. This option is not useful for distributions or general
kernels, but only for kernel developers working on architecture code.
Say N if you are unsure.
endmenu