arch/s390/Kconfig

   1 # SPDX-License-Identifier: GPL-2.0
   2 config MMU
   3         def_bool y
   4
   5 config ZONE_DMA
   6         def_bool y
   7
   8 config CPU_BIG_ENDIAN
   9         def_bool y
  10
  11 config LOCKDEP_SUPPORT
  12         def_bool y
  13
  14 config STACKTRACE_SUPPORT
  15         def_bool y
  16
  17 config RWSEM_GENERIC_SPINLOCK
  18         bool
  19
  20 config RWSEM_XCHGADD_ALGORITHM
  21         def_bool y
  22
  23 config ARCH_HAS_ILOG2_U32
  24         def_bool n
  25
  26 config ARCH_HAS_ILOG2_U64
  27         def_bool n
  28
  29 config GENERIC_HWEIGHT
  30         def_bool y
  31
  32 config GENERIC_BUG
  33         def_bool y if BUG
  34
  35 config GENERIC_BUG_RELATIVE_POINTERS
  36         def_bool y
  37
  38 config ARCH_DMA_ADDR_T_64BIT
  39         def_bool y
  40
  41 config GENERIC_LOCKBREAK
  42         def_bool y if SMP && PREEMPT
  43
  44 config PGSTE
  45         def_bool y if KVM
  46
  47 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
  48         def_bool y
  49
  50 config KEXEC
  51         def_bool y
  52         select KEXEC_CORE
  53
  54 config AUDIT_ARCH
  55         def_bool y
  56
  57 config NO_IOPORT_MAP
  58         def_bool y
  59
  60 config PCI_QUIRKS
  61         def_bool n
  62
  63 config ARCH_SUPPORTS_UPROBES
  64         def_bool y
  65
  66 config S390
  67         def_bool y
  68         select ARCH_BINFMT_ELF_STATE
  69         select ARCH_HAS_DEVMEM_IS_ALLOWED
  70         select ARCH_HAS_ELF_RANDOMIZE
  71         select ARCH_HAS_FORTIFY_SOURCE
  72         select ARCH_HAS_GCOV_PROFILE_ALL
  73         select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
  74         select ARCH_HAS_KCOV
  75         select ARCH_HAS_SET_MEMORY
  76         select ARCH_HAS_SG_CHAIN
  77         select ARCH_HAS_STRICT_KERNEL_RWX
  78         select ARCH_HAS_STRICT_MODULE_RWX
  79         select ARCH_HAS_UBSAN_SANITIZE_ALL
  80         select ARCH_HAVE_NMI_SAFE_CMPXCHG
  81         select ARCH_INLINE_READ_LOCK
  82         select ARCH_INLINE_READ_LOCK_BH
  83         select ARCH_INLINE_READ_LOCK_IRQ
  84         select ARCH_INLINE_READ_LOCK_IRQSAVE
  85         select ARCH_INLINE_READ_TRYLOCK
  86         select ARCH_INLINE_READ_UNLOCK
  87         select ARCH_INLINE_READ_UNLOCK_BH
  88         select ARCH_INLINE_READ_UNLOCK_IRQ
  89         select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
  90         select ARCH_INLINE_SPIN_LOCK
  91         select ARCH_INLINE_SPIN_LOCK_BH
  92         select ARCH_INLINE_SPIN_LOCK_IRQ
  93         select ARCH_INLINE_SPIN_LOCK_IRQSAVE
  94         select ARCH_INLINE_SPIN_TRYLOCK
  95         select ARCH_INLINE_SPIN_TRYLOCK_BH
  96         select ARCH_INLINE_SPIN_UNLOCK
  97         select ARCH_INLINE_SPIN_UNLOCK_BH
  98         select ARCH_INLINE_SPIN_UNLOCK_IRQ
  99         select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
 100         select ARCH_INLINE_WRITE_LOCK
 101         select ARCH_INLINE_WRITE_LOCK_BH
 102         select ARCH_INLINE_WRITE_LOCK_IRQ
 103         select ARCH_INLINE_WRITE_LOCK_IRQSAVE
 104         select ARCH_INLINE_WRITE_TRYLOCK
 105         select ARCH_INLINE_WRITE_UNLOCK
 106         select ARCH_INLINE_WRITE_UNLOCK_BH
 107         select ARCH_INLINE_WRITE_UNLOCK_IRQ
 108         select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
 109         select ARCH_SAVE_PAGE_KEYS if HIBERNATION
 110         select ARCH_SUPPORTS_ATOMIC_RMW
 111         select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
 112         select ARCH_SUPPORTS_NUMA_BALANCING
 113         select ARCH_USE_BUILTIN_BSWAP
 114         select ARCH_USE_CMPXCHG_LOCKREF
 115         select ARCH_WANTS_DYNAMIC_TASK_STRUCT
 116         select ARCH_WANTS_PROT_NUMA_PROT_NONE
 117         select ARCH_WANTS_UBSAN_NO_NULL
 118         select ARCH_WANT_IPC_PARSE_VERSION
 119         select BUILDTIME_EXTABLE_SORT
 120         select CLONE_BACKWARDS2
 121         select DYNAMIC_FTRACE if FUNCTION_TRACER
 122         select GENERIC_CLOCKEVENTS
 123         select GENERIC_CPU_AUTOPROBE
 124         select GENERIC_CPU_DEVICES if !SMP
 125         select GENERIC_FIND_FIRST_BIT
 126         select GENERIC_SMP_IDLE_THREAD
 127         select GENERIC_TIME_VSYSCALL
 128         select HAVE_ALIGNED_STRUCT_PAGE if SLUB
 129         select HAVE_ARCH_AUDITSYSCALL
 130         select HAVE_ARCH_JUMP_LABEL
 131         select CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES
 132         select HAVE_ARCH_SECCOMP_FILTER
 133         select HAVE_ARCH_SOFT_DIRTY
 134         select HAVE_ARCH_TRACEHOOK
 135         select HAVE_ARCH_TRANSPARENT_HUGEPAGE
 136         select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
 137         select HAVE_CMPXCHG_DOUBLE
 138         select HAVE_CMPXCHG_LOCAL
 139         select HAVE_COPY_THREAD_TLS
 140         select HAVE_DEBUG_KMEMLEAK
 141         select HAVE_DMA_API_DEBUG
 142         select HAVE_DMA_CONTIGUOUS
 143         select DMA_NOOP_OPS
 144         select HAVE_DYNAMIC_FTRACE
 145         select HAVE_DYNAMIC_FTRACE_WITH_REGS
 146         select HAVE_EFFICIENT_UNALIGNED_ACCESS
 147         select HAVE_FTRACE_MCOUNT_RECORD
 148         select HAVE_FUNCTION_GRAPH_TRACER
 149         select HAVE_FUNCTION_TRACER
 150         select HAVE_FUTEX_CMPXCHG if FUTEX
 151         select HAVE_GCC_PLUGINS
 152         select HAVE_KERNEL_BZIP2
 153         select HAVE_KERNEL_GZIP
 154         select HAVE_KERNEL_LZ4
 155         select HAVE_KERNEL_LZMA
 156         select HAVE_KERNEL_LZO
 157         select HAVE_KERNEL_XZ
 158         select HAVE_KPROBES
 159         select HAVE_KRETPROBES
 160         select HAVE_KVM
 161         select HAVE_LIVEPATCH
 162         select HAVE_PERF_REGS
 163         select HAVE_PERF_USER_STACK_DUMP
 164         select HAVE_MEMBLOCK
 165         select HAVE_MEMBLOCK_NODE_MAP
 166         select HAVE_MEMBLOCK_PHYS_MAP
 167         select HAVE_MOD_ARCH_SPECIFIC
 168         select HAVE_OPROFILE
 169         select HAVE_PERF_EVENTS
 170         select HAVE_REGS_AND_STACK_ACCESS_API
 171         select HAVE_SYSCALL_TRACEPOINTS
 172         select HAVE_VIRT_CPU_ACCOUNTING
 173         select MODULES_USE_ELF_RELA
 174         select NO_BOOTMEM
 175         select OLD_SIGACTION
 176         select OLD_SIGSUSPEND3
 177         select SPARSE_IRQ
 178         select SYSCTL_EXCEPTION_TRACE
 179         select THREAD_INFO_IN_TASK
 180         select TTY
 181         select VIRT_CPU_ACCOUNTING
 182         select ARCH_HAS_SCALED_CPUTIME
 183         select VIRT_TO_BUS
 184         select HAVE_NMI
 185
 186
 187 config SCHED_OMIT_FRAME_POINTER
 188         def_bool y
 189
 190 config PGTABLE_LEVELS
 191         int
 192         default 5
 193
 194 source "init/Kconfig"
 195
 196 source "kernel/Kconfig.freezer"
 197
 198 source "kernel/livepatch/Kconfig"
 199
 200 menu "Processor type and features"
 201
 202 config HAVE_MARCH_Z900_FEATURES
 203         def_bool n
 204
 205 config HAVE_MARCH_Z990_FEATURES
 206         def_bool n
 207         select HAVE_MARCH_Z900_FEATURES
 208
 209 config HAVE_MARCH_Z9_109_FEATURES
 210         def_bool n
 211         select HAVE_MARCH_Z990_FEATURES
 212
 213 config HAVE_MARCH_Z10_FEATURES
 214         def_bool n
 215         select HAVE_MARCH_Z9_109_FEATURES
 216
 217 config HAVE_MARCH_Z196_FEATURES
 218         def_bool n
 219         select HAVE_MARCH_Z10_FEATURES
 220
 221 config HAVE_MARCH_ZEC12_FEATURES
 222         def_bool n
 223         select HAVE_MARCH_Z196_FEATURES
 224
 225 config HAVE_MARCH_Z13_FEATURES
 226         def_bool n
 227         select HAVE_MARCH_ZEC12_FEATURES
 228
 229 config HAVE_MARCH_Z14_FEATURES
 230         def_bool n
 231         select HAVE_MARCH_Z13_FEATURES
 232
 233 choice
 234         prompt "Processor type"
 235         default MARCH_Z196
 236
 237 config MARCH_Z900
 238         bool "IBM zSeries model z800 and z900"
 239         select HAVE_MARCH_Z900_FEATURES
 240         help
 241           Select this to enable optimizations for model z800/z900 (2064 and
 242           2066 series). This will enable some optimizations that are not
 243           available on older ESA/390 (31 Bit) only CPUs.
 244
 245 config MARCH_Z990
 246         bool "IBM zSeries model z890 and z990"
 247         select HAVE_MARCH_Z990_FEATURES
 248         help
 249           Select this to enable optimizations for model z890/z990 (2084 and
 250           2086 series). The kernel will be slightly faster but will not work
 251           on older machines.
 252
 253 config MARCH_Z9_109
 254         bool "IBM System z9"
 255         select HAVE_MARCH_Z9_109_FEATURES
 256         help
 257           Select this to enable optimizations for IBM System z9 (2094 and
 258           2096 series). The kernel will be slightly faster but will not work
 259           on older machines.
 260
 261 config MARCH_Z10
 262         bool "IBM System z10"
 263         select HAVE_MARCH_Z10_FEATURES
 264         help
 265           Select this to enable optimizations for IBM System z10 (2097 and
 266           2098 series). The kernel will be slightly faster but will not work
 267           on older machines.
 268
 269 config MARCH_Z196
 270         bool "IBM zEnterprise 114 and 196"
 271         select HAVE_MARCH_Z196_FEATURES
 272         help
 273           Select this to enable optimizations for IBM zEnterprise 114 and 196
 274           (2818 and 2817 series). The kernel will be slightly faster but will
 275           not work on older machines.
 276
 277 config MARCH_ZEC12
 278         bool "IBM zBC12 and zEC12"
 279         select HAVE_MARCH_ZEC12_FEATURES
 280         help
 281           Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
 282           2827 series). The kernel will be slightly faster but will not work on
 283           older machines.
 284
 285 config MARCH_Z13
 286         bool "IBM z13s and z13"
 287         select HAVE_MARCH_Z13_FEATURES
 288         help
 289           Select this to enable optimizations for IBM z13s and z13 (2965 and
 290           2964 series). The kernel will be slightly faster but will not work on
 291           older machines.
 292
 293 config MARCH_Z14
 294         bool "IBM z14"
 295         select HAVE_MARCH_Z14_FEATURES
 296         help
 297           Select this to enable optimizations for IBM z14 (3906 series).
 298           The kernel will be slightly faster but will not work on older
 299           machines.
 300
 301 endchoice
 302
 303 config MARCH_Z900_TUNE
 304         def_bool TUNE_Z900 || MARCH_Z900 && TUNE_DEFAULT
 305
 306 config MARCH_Z990_TUNE
 307         def_bool TUNE_Z990 || MARCH_Z990 && TUNE_DEFAULT
 308
 309 config MARCH_Z9_109_TUNE
 310         def_bool TUNE_Z9_109 || MARCH_Z9_109 && TUNE_DEFAULT
 311
 312 config MARCH_Z10_TUNE
 313         def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
 314
 315 config MARCH_Z196_TUNE
 316         def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
 317
 318 config MARCH_ZEC12_TUNE
 319         def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
 320
 321 config MARCH_Z13_TUNE
 322         def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
 323
 324 config MARCH_Z14_TUNE
 325         def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
 326
 327 choice
 328         prompt "Tune code generation"
 329         default TUNE_DEFAULT
 330         help
 331           Cause the compiler to tune (-mtune) the generated code for a machine.
 332           This will make the code run faster on the selected machine but
 333           somewhat slower on other machines.
 334           This option only changes how the compiler emits instructions, not the
 335           selection of instructions itself, so the resulting kernel will run on
 336           all other machines.
 337
 338 config TUNE_DEFAULT
 339         bool "Default"
 340         help
 341           Tune the generated code for the target processor for which the kernel
 342           will be compiled.
 343
 344 config TUNE_Z900
 345         bool "IBM zSeries model z800 and z900"
 346
 347 config TUNE_Z990
 348         bool "IBM zSeries model z890 and z990"
 349
 350 config TUNE_Z9_109
 351         bool "IBM System z9"
 352
 353 config TUNE_Z10
 354         bool "IBM System z10"
 355
 356 config TUNE_Z196
 357         bool "IBM zEnterprise 114 and 196"
 358
 359 config TUNE_ZEC12
 360         bool "IBM zBC12 and zEC12"
 361
 362 config TUNE_Z13
 363         bool "IBM z13"
 364
 365 config TUNE_Z14
 366         bool "IBM z14"
 367
 368 endchoice
 369
 370 config 64BIT
 371         def_bool y
 372
 373 config COMPAT
 374         def_bool y
 375         prompt "Kernel support for 31 bit emulation"
 376         select COMPAT_BINFMT_ELF if BINFMT_ELF
 377         select ARCH_WANT_OLD_COMPAT_IPC
 378         select COMPAT_OLD_SIGACTION
 379         depends on MULTIUSER
 380         help
 381           Select this option if you want to enable your system kernel to
 382           handle system-calls from ELF binaries for 31 bit ESA.  This option
 383           (and some other stuff like libraries and such) is needed for
 384           executing 31 bit applications.  It is safe to say "Y".
 385
 386 config SYSVIPC_COMPAT
 387         def_bool y if COMPAT && SYSVIPC
 388
 389 config SMP
 390         def_bool y
 391         prompt "Symmetric multi-processing support"
 392         ---help---
 393           This enables support for systems with more than one CPU. If you have
 394           a system with only one CPU, like most personal computers, say N. If
 395           you have a system with more than one CPU, say Y.
 396
 397           If you say N here, the kernel will run on uni- and multiprocessor
 398           machines, but will use only one CPU of a multiprocessor machine. If
 399           you say Y here, the kernel will run on many, but not all,
 400           uniprocessor machines. On a uniprocessor machine, the kernel
 401           will run faster if you say N here.
 402
 403           See also the SMP-HOWTO available at
 404           <http://www.tldp.org/docs.html#howto>.
 405
 406           Even if you don't know what to do here, say Y.
 407
 408 config NR_CPUS
 409         int "Maximum number of CPUs (2-512)"
 410         range 2 512
 411         depends on SMP
 412         default "64"
 413         help
 414           This allows you to specify the maximum number of CPUs which this
 415           kernel will support. The maximum supported value is 512 and the
 416           minimum value which makes sense is 2.
 417
 418           This is purely to save memory - each supported CPU adds
 419           approximately sixteen kilobytes to the kernel image.
 420
 421 config HOTPLUG_CPU
 422         def_bool y
 423         prompt "Support for hot-pluggable CPUs"
 424         depends on SMP
 425         help
 426           Say Y here to be able to turn CPUs off and on. CPUs
 427           can be controlled through /sys/devices/system/cpu/cpu#.
 428           Say N if you want to disable CPU hotplug.
 429
 430 # Some NUMA nodes have memory ranges that span
 431 # other nodes.  Even though a pfn is valid and
 432 # between a node's start and end pfns, it may not
 433 # reside on that node.  See memmap_init_zone()
 434 # for details. <- They meant memory holes!
 435 config NODES_SPAN_OTHER_NODES
 436         def_bool NUMA
 437
 438 config NUMA
 439         bool "NUMA support"
 440         depends on SMP && SCHED_TOPOLOGY
 441         default n
 442         help
 443           Enable NUMA support
 444
 445           This option adds NUMA support to the kernel.
 446
 447           An operation mode can be selected by appending
 448           numa=<method> to the kernel command line.
 449
 450           The default behaviour is identical to appending numa=plain to
 451           the command line. This will create just one node with all
 452           available memory and all CPUs in it.
 453
 454 config NODES_SHIFT
 455         int "Maximum NUMA nodes (as a power of 2)"
 456         range 1 10
 457         depends on NUMA
 458         default "4"
 459         help
 460           Specify the maximum number of NUMA nodes available on the target
 461           system. Increases memory reserved to accommodate various tables.
 462
 463 menu "Select NUMA modes"
 464         depends on NUMA
 465
 466 config NUMA_EMU
 467         bool "NUMA emulation"
 468         default y
 469         help
 470           Numa emulation mode will split the available system memory into
 471           equal chunks which then are distributed over the configured number
 472           of nodes in a round-robin manner.
 473
 474           The number of fake nodes is limited by the number of available memory
 475           chunks (i.e. memory size / fake size) and the number of supported
 476           nodes in the kernel.
 477
 478           The CPUs are assigned to the nodes in a way that partially respects
 479           the original machine topology (if supported by the machine).
 480           Fair distribution of the CPUs is not guaranteed.
 481
 482 config EMU_SIZE
 483         hex "NUMA emulation memory chunk size"
 484         default 0x10000000
 485         range 0x400000 0x100000000
 486         depends on NUMA_EMU
 487         help
 488           Select the default size by which the memory is chopped and then
 489           assigned to emulated NUMA nodes.
 490
 491           This can be overridden by specifying
 492
 493           emu_size=<n>
 494
 495           on the kernel command line where also suffixes K, M, G, and T are
 496           supported.
 497
 498 endmenu
 499
 500 config SCHED_SMT
 501         def_bool n
 502
 503 config SCHED_MC
 504         def_bool n
 505
 506 config SCHED_BOOK
 507         def_bool n
 508
 509 config SCHED_DRAWER
 510         def_bool n
 511
 512 config SCHED_TOPOLOGY
 513         def_bool y
 514         prompt "Topology scheduler support"
 515         depends on SMP
 516         select SCHED_SMT
 517         select SCHED_MC
 518         select SCHED_BOOK
 519         select SCHED_DRAWER
 520         help
 521           Topology scheduler support improves the CPU scheduler's decision
 522           making when dealing with machines that have multi-threading,
 523           multiple cores or multiple books.
 524
 525 source kernel/Kconfig.preempt
 526
 527 source kernel/Kconfig.hz
 528
 529 config ARCH_RANDOM
 530         def_bool y
 531         prompt "s390 architectural random number generation API"
 532         help
 533           Enable the s390 architectural random number generation API
 534           to provide random data for all consumers within the Linux
 535           kernel.
 536
 537           When enabled the arch_random_* functions declared in linux/random.h
 538           are implemented. The implementation is based on the s390 CPACF
 539           instruction subfunction TRNG which provides a real true random
 540           number generator.
 541
 542           If unsure, say Y.
 543
 544 config KERNEL_NOBP
 545         def_bool n
 546         prompt "Enable modified branch prediction for the kernel by default"
 547         help
 548           If this option is selected the kernel will switch to a modified
 549           branch prediction mode if the firmware interface is available.
 550           The modified branch prediction mode improves the behaviour in
 551           regard to speculative execution.
 552
 553           With the option enabled the kernel parameter "nobp=0" or "nospec"
 554           can be used to run the kernel in the normal branch prediction mode.
 555
 556           With the option disabled the modified branch prediction mode is
 557           enabled with the "nobp=1" kernel parameter.
 558
 559           If unsure, say N.
 560
 561 endmenu
 562
 563 menu "Memory setup"
 564
 565 config ARCH_SPARSEMEM_ENABLE
 566         def_bool y
 567         select SPARSEMEM_VMEMMAP_ENABLE
 568         select SPARSEMEM_VMEMMAP
 569
 570 config ARCH_SPARSEMEM_DEFAULT
 571         def_bool y
 572
 573 config ARCH_SELECT_MEMORY_MODEL
 574         def_bool y
 575
 576 config ARCH_ENABLE_MEMORY_HOTPLUG
 577         def_bool y if SPARSEMEM
 578
 579 config ARCH_ENABLE_MEMORY_HOTREMOVE
 580         def_bool y
 581
 582 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
 583         def_bool y
 584
 585 config FORCE_MAX_ZONEORDER
 586         int
 587         default "9"
 588
 589 source "mm/Kconfig"
 590
 591 config MAX_PHYSMEM_BITS
 592         int "Maximum size of supported physical memory in bits (42-53)"
 593         range 42 53
 594         default "46"
 595         help
 596           This option specifies the maximum supported size of physical memory
 597           in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
 598           Increasing the number of bits also increases the kernel image size.
 599           By default 46 bits (64TB) are supported.
 600
 601 config PACK_STACK
 602         def_bool y
 603         prompt "Pack kernel stack"
 604         help
 605           This option enables the compiler option -mkernel-backchain if it
 606           is available. If the option is available the compiler supports
 607           the new stack layout which dramatically reduces the minimum stack
 608           frame size. With an old compiler a non-leaf function needs a
 609           minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
 610           -mkernel-backchain the minimum size drops to 16 byte on 31 bit
 611           and 24 byte on 64 bit.
 612
 613           Say Y if you are unsure.
 614
 615 config CHECK_STACK
 616         def_bool y
 617         prompt "Detect kernel stack overflow"
 618         help
 619           This option enables the compiler option -mstack-guard and
 620           -mstack-size if they are available. If the compiler supports them
 621           it will emit additional code to each function prolog to trigger
 622           an illegal operation if the kernel stack is about to overflow.
 623
 624           Say N if you are unsure.
 625
 626 config STACK_GUARD
 627         int "Size of the guard area (128-1024)"
 628         range 128 1024
 629         depends on CHECK_STACK
 630         default "256"
 631         help
 632           This allows you to specify the size of the guard area at the lower
 633           end of the kernel stack. If the kernel stack points into the guard
 634           area on function entry an illegal operation is triggered. The size
 635           needs to be a power of 2. Please keep in mind that the size of an
 636           interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
 637           The minimum size for the stack guard should be 256 for 31 bit and
 638           512 for 64 bit.
 639
 640 config WARN_DYNAMIC_STACK
 641         def_bool n
 642         prompt "Emit compiler warnings for function with dynamic stack usage"
 643         help
 644           This option enables the compiler option -mwarn-dynamicstack. If the
 645           compiler supports this options generates warnings for functions
 646           that dynamically allocate stack space using alloca.
 647
 648           Say N if you are unsure.
 649
 650 endmenu
 651
 652 menu "I/O subsystem"
 653
 654 config QDIO
 655         def_tristate y
 656         prompt "QDIO support"
 657         ---help---
 658           This driver provides the Queued Direct I/O base support for
 659           IBM System z.
 660
 661           To compile this driver as a module, choose M here: the
 662           module will be called qdio.
 663
 664           If unsure, say Y.
 665
 666 menuconfig PCI
 667         bool "PCI support"
 668         select PCI_MSI
 669         select IOMMU_SUPPORT
 670         help
 671           Enable PCI support.
 672
 673 if PCI
 674
 675 config PCI_NR_FUNCTIONS
 676         int "Maximum number of PCI functions (1-4096)"
 677         range 1 4096
 678         default "128"
 679         help
 680           This allows you to specify the maximum number of PCI functions which
 681           this kernel will support.
 682
 683 source "drivers/pci/Kconfig"
 684
 685 endif   # PCI
 686
 687 config PCI_DOMAINS
 688         def_bool PCI
 689
 690 config HAS_IOMEM
 691         def_bool PCI
 692
 693 config IOMMU_HELPER
 694         def_bool PCI
 695
 696 config NEED_SG_DMA_LENGTH
 697         def_bool PCI
 698
 699 config NEED_DMA_MAP_STATE
 700         def_bool PCI
 701
 702 config CHSC_SCH
 703         def_tristate m
 704         prompt "Support for CHSC subchannels"
 705         help
 706           This driver allows usage of CHSC subchannels. A CHSC subchannel
 707           is usually present on LPAR only.
 708           The driver creates a device /dev/chsc, which may be used to
 709           obtain I/O configuration information about the machine and
 710           to issue asynchronous chsc commands (DANGEROUS).
 711           You will usually only want to use this interface on a special
 712           LPAR designated for system management.
 713
 714           To compile this driver as a module, choose M here: the
 715           module will be called chsc_sch.
 716
 717           If unsure, say N.
 718
 719 config SCM_BUS
 720         def_bool y
 721         prompt "SCM bus driver"
 722         help
 723           Bus driver for Storage Class Memory.
 724
 725 config EADM_SCH
 726         def_tristate m
 727         prompt "Support for EADM subchannels"
 728         depends on SCM_BUS
 729         help
 730           This driver allows usage of EADM subchannels. EADM subchannels act
 731           as a communication vehicle for SCM increments.
 732
 733           To compile this driver as a module, choose M here: the
 734           module will be called eadm_sch.
 735
 736 config VFIO_CCW
 737         def_tristate n
 738         prompt "Support for VFIO-CCW subchannels"
 739         depends on S390_CCW_IOMMU && VFIO_MDEV
 740         help
 741           This driver allows usage of I/O subchannels via VFIO-CCW.
 742
 743           To compile this driver as a module, choose M here: the
 744           module will be called vfio_ccw.
 745
 746 endmenu
 747
 748 menu "Dump support"
 749
 750 config CRASH_DUMP
 751         bool "kernel crash dumps"
 752         depends on SMP
 753         select KEXEC
 754         help
 755           Generate crash dump after being started by kexec.
 756           Crash dump kernels are loaded in the main kernel with kexec-tools
 757           into a specially reserved region and then later executed after
 758           a crash by kdump/kexec.
 759           Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
 760           This option also enables s390 zfcpdump.
 761           See also <file:Documentation/s390/zfcpdump.txt>
 762
 763 endmenu
 764
 765 menu "Executable file formats / Emulations"
 766
 767 source "fs/Kconfig.binfmt"
 768
 769 config SECCOMP
 770         def_bool y
 771         prompt "Enable seccomp to safely compute untrusted bytecode"
 772         depends on PROC_FS
 773         help
 774           This kernel feature is useful for number crunching applications
 775           that may need to compute untrusted bytecode during their
 776           execution. By using pipes or other transports made available to
 777           the process as file descriptors supporting the read/write
 778           syscalls, it's possible to isolate those applications in
 779           their own address space using seccomp. Once seccomp is
 780           enabled via /proc/<pid>/seccomp, it cannot be disabled
 781           and the task is only allowed to execute a few safe syscalls
 782           defined by each seccomp mode.
 783
 784           If unsure, say Y.
 785
 786 endmenu
 787
 788 menu "Power Management"
 789
 790 config ARCH_HIBERNATION_POSSIBLE
 791         def_bool y
 792
 793 source "kernel/power/Kconfig"
 794
 795 endmenu
 796
 797 source "net/Kconfig"
 798
 799 config PCMCIA
 800         def_bool n
 801
 802 config CCW
 803         def_bool y
 804
 805 source "drivers/Kconfig"
 806
 807 source "fs/Kconfig"
 808
 809 source "arch/s390/Kconfig.debug"
 810
 811 source "security/Kconfig"
 812
 813 source "crypto/Kconfig"
 814
 815 source "lib/Kconfig"
 816
 817 menu "Virtualization"
 818
 819 config PFAULT
 820         def_bool y
 821         prompt "Pseudo page fault support"
 822         help
 823           Select this option, if you want to use PFAULT pseudo page fault
 824           handling under VM. If running native or in LPAR, this option
 825           has no effect. If your VM does not support PFAULT, PAGEEX
 826           pseudo page fault handling will be used.
 827           Note that VM 4.2 supports PFAULT but has a bug in its
 828           implementation that causes some problems.
 829           Everybody who wants to run Linux under VM != VM4.2 should select
 830           this option.
 831
 832 config CMM
 833         def_tristate n
 834         prompt "Cooperative memory management"
 835         help
 836           Select this option, if you want to enable the kernel interface
 837           to reduce the memory size of the system. This is accomplished
 838           by allocating pages of memory and put them "on hold". This only
 839           makes sense for a system running under VM where the unused pages
 840           will be reused by VM for other guest systems. The interface
 841           allows an external monitor to balance memory of many systems.
 842           Everybody who wants to run Linux under VM should select this
 843           option.
 844
 845 config CMM_IUCV
 846         def_bool y
 847         prompt "IUCV special message interface to cooperative memory management"
 848         depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
 849         help
 850           Select this option to enable the special message interface to
 851           the cooperative memory management.
 852
 853 config APPLDATA_BASE
 854         def_bool n
 855         prompt "Linux - VM Monitor Stream, base infrastructure"
 856         depends on PROC_FS
 857         help
 858           This provides a kernel interface for creating and updating z/VM APPLDATA
 859           monitor records. The monitor records are updated at certain time
 860           intervals, once the timer is started.
 861           Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
 862           i.e. enables or disables monitoring on the Linux side.
 863           A custom interval value (in seconds) can be written to
 864           /proc/appldata/interval.
 865
 866           Defaults are 60 seconds interval and timer off.
 867           The /proc entries can also be read from, showing the current settings.
 868
 869 config APPLDATA_MEM
 870         def_tristate m
 871         prompt "Monitor memory management statistics"
 872         depends on APPLDATA_BASE && VM_EVENT_COUNTERS
 873         help
 874           This provides memory management related data to the Linux - VM Monitor
 875           Stream, like paging/swapping rate, memory utilisation, etc.
 876           Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
 877           APPLDATA monitor record, i.e. enables or disables monitoring this record
 878           on the z/VM side.
 879
 880           Default is disabled.
 881           The /proc entry can also be read from, showing the current settings.
 882
 883           This can also be compiled as a module, which will be called
 884           appldata_mem.o.
 885
 886 config APPLDATA_OS
 887         def_tristate m
 888         prompt "Monitor OS statistics"
 889         depends on APPLDATA_BASE
 890         help
 891           This provides OS related data to the Linux - VM Monitor Stream, like
 892           CPU utilisation, etc.
 893           Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
 894           APPLDATA monitor record, i.e. enables or disables monitoring this record
 895           on the z/VM side.
 896
 897           Default is disabled.
 898           This can also be compiled as a module, which will be called
 899           appldata_os.o.
 900
 901 config APPLDATA_NET_SUM
 902         def_tristate m
 903         prompt "Monitor overall network statistics"
 904         depends on APPLDATA_BASE && NET
 905         help
 906           This provides network related data to the Linux - VM Monitor Stream,
 907           currently there is only a total sum of network I/O statistics, no
 908           per-interface data.
 909           Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
 910           APPLDATA monitor record, i.e. enables or disables monitoring this record
 911           on the z/VM side.
 912
 913           Default is disabled.
 914           This can also be compiled as a module, which will be called
 915           appldata_net_sum.o.
 916
 917 config S390_HYPFS_FS
 918         def_bool y
 919         prompt "s390 hypervisor file system support"
 920         select SYS_HYPERVISOR
 921         help
 922           This is a virtual file system intended to provide accounting
 923           information in an s390 hypervisor environment.
 924
 925 source "arch/s390/kvm/Kconfig"
 926
 927 config S390_GUEST
 928         def_bool y
 929         prompt "s390 support for virtio devices"
 930         select TTY
 931         select VIRTUALIZATION
 932         select VIRTIO
 933         select VIRTIO_CONSOLE
 934         help
 935           Enabling this option adds support for virtio based paravirtual device
 936           drivers on s390.
 937
 938           Select this option if you want to run the kernel as a guest under
 939           the KVM hypervisor.
 940
 941 endmenu
 942
 943 config KMSG_IDS
 944         def_bool y
 945         prompt "Kernel message numbers"
 946         help
 947           Select this option if you want to include a message number to the
 948           prefix for kernel messages issued by the s390 architecture and
 949           driver code. See "Documentation/s390/kmsg.txt" for more details.