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_KERNEL_BZIP2
 152         select HAVE_KERNEL_GZIP
 153         select HAVE_KERNEL_LZ4
 154         select HAVE_KERNEL_LZMA
 155         select HAVE_KERNEL_LZO
 156         select HAVE_KERNEL_XZ
 157         select HAVE_KPROBES
 158         select HAVE_KRETPROBES
 159         select HAVE_KVM
 160         select HAVE_LIVEPATCH
 161         select HAVE_MEMBLOCK
 162         select HAVE_MEMBLOCK_NODE_MAP
 163         select HAVE_MEMBLOCK_PHYS_MAP
 164         select HAVE_MOD_ARCH_SPECIFIC
 165         select HAVE_OPROFILE
 166         select HAVE_PERF_EVENTS
 167         select HAVE_REGS_AND_STACK_ACCESS_API
 168         select HAVE_SYSCALL_TRACEPOINTS
 169         select HAVE_VIRT_CPU_ACCOUNTING
 170         select MODULES_USE_ELF_RELA
 171         select NO_BOOTMEM
 172         select OLD_SIGACTION
 173         select OLD_SIGSUSPEND3
 174         select SPARSE_IRQ
 175         select SYSCTL_EXCEPTION_TRACE
 176         select THREAD_INFO_IN_TASK
 177         select TTY
 178         select VIRT_CPU_ACCOUNTING
 179         select ARCH_HAS_SCALED_CPUTIME
 180         select VIRT_TO_BUS
 181         select HAVE_NMI
 182
 183
 184 config SCHED_OMIT_FRAME_POINTER
 185         def_bool y
 186
 187 config PGTABLE_LEVELS
 188         int
 189         default 5
 190
 191 source "init/Kconfig"
 192
 193 source "kernel/Kconfig.freezer"
 194
 195 source "kernel/livepatch/Kconfig"
 196
 197 menu "Processor type and features"
 198
 199 config HAVE_MARCH_Z900_FEATURES
 200         def_bool n
 201
 202 config HAVE_MARCH_Z990_FEATURES
 203         def_bool n
 204         select HAVE_MARCH_Z900_FEATURES
 205
 206 config HAVE_MARCH_Z9_109_FEATURES
 207         def_bool n
 208         select HAVE_MARCH_Z990_FEATURES
 209
 210 config HAVE_MARCH_Z10_FEATURES
 211         def_bool n
 212         select HAVE_MARCH_Z9_109_FEATURES
 213
 214 config HAVE_MARCH_Z196_FEATURES
 215         def_bool n
 216         select HAVE_MARCH_Z10_FEATURES
 217
 218 config HAVE_MARCH_ZEC12_FEATURES
 219         def_bool n
 220         select HAVE_MARCH_Z196_FEATURES
 221
 222 config HAVE_MARCH_Z13_FEATURES
 223         def_bool n
 224         select HAVE_MARCH_ZEC12_FEATURES
 225
 226 config HAVE_MARCH_Z14_FEATURES
 227         def_bool n
 228         select HAVE_MARCH_Z13_FEATURES
 229
 230 choice
 231         prompt "Processor type"
 232         default MARCH_Z196
 233
 234 config MARCH_Z900
 235         bool "IBM zSeries model z800 and z900"
 236         select HAVE_MARCH_Z900_FEATURES
 237         help
 238           Select this to enable optimizations for model z800/z900 (2064 and
 239           2066 series). This will enable some optimizations that are not
 240           available on older ESA/390 (31 Bit) only CPUs.
 241
 242 config MARCH_Z990
 243         bool "IBM zSeries model z890 and z990"
 244         select HAVE_MARCH_Z990_FEATURES
 245         help
 246           Select this to enable optimizations for model z890/z990 (2084 and
 247           2086 series). The kernel will be slightly faster but will not work
 248           on older machines.
 249
 250 config MARCH_Z9_109
 251         bool "IBM System z9"
 252         select HAVE_MARCH_Z9_109_FEATURES
 253         help
 254           Select this to enable optimizations for IBM System z9 (2094 and
 255           2096 series). The kernel will be slightly faster but will not work
 256           on older machines.
 257
 258 config MARCH_Z10
 259         bool "IBM System z10"
 260         select HAVE_MARCH_Z10_FEATURES
 261         help
 262           Select this to enable optimizations for IBM System z10 (2097 and
 263           2098 series). The kernel will be slightly faster but will not work
 264           on older machines.
 265
 266 config MARCH_Z196
 267         bool "IBM zEnterprise 114 and 196"
 268         select HAVE_MARCH_Z196_FEATURES
 269         help
 270           Select this to enable optimizations for IBM zEnterprise 114 and 196
 271           (2818 and 2817 series). The kernel will be slightly faster but will
 272           not work on older machines.
 273
 274 config MARCH_ZEC12
 275         bool "IBM zBC12 and zEC12"
 276         select HAVE_MARCH_ZEC12_FEATURES
 277         help
 278           Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
 279           2827 series). The kernel will be slightly faster but will not work on
 280           older machines.
 281
 282 config MARCH_Z13
 283         bool "IBM z13s and z13"
 284         select HAVE_MARCH_Z13_FEATURES
 285         help
 286           Select this to enable optimizations for IBM z13s and z13 (2965 and
 287           2964 series). The kernel will be slightly faster but will not work on
 288           older machines.
 289
 290 config MARCH_Z14
 291         bool "IBM z14"
 292         select HAVE_MARCH_Z14_FEATURES
 293         help
 294           Select this to enable optimizations for IBM z14 (3906 series).
 295           The kernel will be slightly faster but will not work on older
 296           machines.
 297
 298 endchoice
 299
 300 config MARCH_Z900_TUNE
 301         def_bool TUNE_Z900 || MARCH_Z900 && TUNE_DEFAULT
 302
 303 config MARCH_Z990_TUNE
 304         def_bool TUNE_Z990 || MARCH_Z990 && TUNE_DEFAULT
 305
 306 config MARCH_Z9_109_TUNE
 307         def_bool TUNE_Z9_109 || MARCH_Z9_109 && TUNE_DEFAULT
 308
 309 config MARCH_Z10_TUNE
 310         def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
 311
 312 config MARCH_Z196_TUNE
 313         def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
 314
 315 config MARCH_ZEC12_TUNE
 316         def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
 317
 318 config MARCH_Z13_TUNE
 319         def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
 320
 321 config MARCH_Z14_TUNE
 322         def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
 323
 324 choice
 325         prompt "Tune code generation"
 326         default TUNE_DEFAULT
 327         help
 328           Cause the compiler to tune (-mtune) the generated code for a machine.
 329           This will make the code run faster on the selected machine but
 330           somewhat slower on other machines.
 331           This option only changes how the compiler emits instructions, not the
 332           selection of instructions itself, so the resulting kernel will run on
 333           all other machines.
 334
 335 config TUNE_DEFAULT
 336         bool "Default"
 337         help
 338           Tune the generated code for the target processor for which the kernel
 339           will be compiled.
 340
 341 config TUNE_Z900
 342         bool "IBM zSeries model z800 and z900"
 343
 344 config TUNE_Z990
 345         bool "IBM zSeries model z890 and z990"
 346
 347 config TUNE_Z9_109
 348         bool "IBM System z9"
 349
 350 config TUNE_Z10
 351         bool "IBM System z10"
 352
 353 config TUNE_Z196
 354         bool "IBM zEnterprise 114 and 196"
 355
 356 config TUNE_ZEC12
 357         bool "IBM zBC12 and zEC12"
 358
 359 config TUNE_Z13
 360         bool "IBM z13"
 361
 362 config TUNE_Z14
 363         bool "IBM z14"
 364
 365 endchoice
 366
 367 config 64BIT
 368         def_bool y
 369
 370 config COMPAT
 371         def_bool y
 372         prompt "Kernel support for 31 bit emulation"
 373         select COMPAT_BINFMT_ELF if BINFMT_ELF
 374         select ARCH_WANT_OLD_COMPAT_IPC
 375         select COMPAT_OLD_SIGACTION
 376         depends on MULTIUSER
 377         help
 378           Select this option if you want to enable your system kernel to
 379           handle system-calls from ELF binaries for 31 bit ESA.  This option
 380           (and some other stuff like libraries and such) is needed for
 381           executing 31 bit applications.  It is safe to say "Y".
 382
 383 config SYSVIPC_COMPAT
 384         def_bool y if COMPAT && SYSVIPC
 385
 386 config SMP
 387         def_bool y
 388         prompt "Symmetric multi-processing support"
 389         ---help---
 390           This enables support for systems with more than one CPU. If you have
 391           a system with only one CPU, like most personal computers, say N. If
 392           you have a system with more than one CPU, say Y.
 393
 394           If you say N here, the kernel will run on uni- and multiprocessor
 395           machines, but will use only one CPU of a multiprocessor machine. If
 396           you say Y here, the kernel will run on many, but not all,
 397           uniprocessor machines. On a uniprocessor machine, the kernel
 398           will run faster if you say N here.
 399
 400           See also the SMP-HOWTO available at
 401           <http://www.tldp.org/docs.html#howto>.
 402
 403           Even if you don't know what to do here, say Y.
 404
 405 config NR_CPUS
 406         int "Maximum number of CPUs (2-512)"
 407         range 2 512
 408         depends on SMP
 409         default "64"
 410         help
 411           This allows you to specify the maximum number of CPUs which this
 412           kernel will support. The maximum supported value is 512 and the
 413           minimum value which makes sense is 2.
 414
 415           This is purely to save memory - each supported CPU adds
 416           approximately sixteen kilobytes to the kernel image.
 417
 418 config HOTPLUG_CPU
 419         def_bool y
 420         prompt "Support for hot-pluggable CPUs"
 421         depends on SMP
 422         help
 423           Say Y here to be able to turn CPUs off and on. CPUs
 424           can be controlled through /sys/devices/system/cpu/cpu#.
 425           Say N if you want to disable CPU hotplug.
 426
 427 # Some NUMA nodes have memory ranges that span
 428 # other nodes.  Even though a pfn is valid and
 429 # between a node's start and end pfns, it may not
 430 # reside on that node.  See memmap_init_zone()
 431 # for details. <- They meant memory holes!
 432 config NODES_SPAN_OTHER_NODES
 433         def_bool NUMA
 434
 435 config NUMA
 436         bool "NUMA support"
 437         depends on SMP && SCHED_TOPOLOGY
 438         default n
 439         help
 440           Enable NUMA support
 441
 442           This option adds NUMA support to the kernel.
 443
 444           An operation mode can be selected by appending
 445           numa=<method> to the kernel command line.
 446
 447           The default behaviour is identical to appending numa=plain to
 448           the command line. This will create just one node with all
 449           available memory and all CPUs in it.
 450
 451 config NODES_SHIFT
 452         int "Maximum NUMA nodes (as a power of 2)"
 453         range 1 10
 454         depends on NUMA
 455         default "4"
 456         help
 457           Specify the maximum number of NUMA nodes available on the target
 458           system. Increases memory reserved to accommodate various tables.
 459
 460 menu "Select NUMA modes"
 461         depends on NUMA
 462
 463 config NUMA_EMU
 464         bool "NUMA emulation"
 465         default y
 466         help
 467           Numa emulation mode will split the available system memory into
 468           equal chunks which then are distributed over the configured number
 469           of nodes in a round-robin manner.
 470
 471           The number of fake nodes is limited by the number of available memory
 472           chunks (i.e. memory size / fake size) and the number of supported
 473           nodes in the kernel.
 474
 475           The CPUs are assigned to the nodes in a way that partially respects
 476           the original machine topology (if supported by the machine).
 477           Fair distribution of the CPUs is not guaranteed.
 478
 479 config EMU_SIZE
 480         hex "NUMA emulation memory chunk size"
 481         default 0x10000000
 482         range 0x400000 0x100000000
 483         depends on NUMA_EMU
 484         help
 485           Select the default size by which the memory is chopped and then
 486           assigned to emulated NUMA nodes.
 487
 488           This can be overridden by specifying
 489
 490           emu_size=<n>
 491
 492           on the kernel command line where also suffixes K, M, G, and T are
 493           supported.
 494
 495 endmenu
 496
 497 config SCHED_SMT
 498         def_bool n
 499
 500 config SCHED_MC
 501         def_bool n
 502
 503 config SCHED_BOOK
 504         def_bool n
 505
 506 config SCHED_DRAWER
 507         def_bool n
 508
 509 config SCHED_TOPOLOGY
 510         def_bool y
 511         prompt "Topology scheduler support"
 512         depends on SMP
 513         select SCHED_SMT
 514         select SCHED_MC
 515         select SCHED_BOOK
 516         select SCHED_DRAWER
 517         help
 518           Topology scheduler support improves the CPU scheduler's decision
 519           making when dealing with machines that have multi-threading,
 520           multiple cores or multiple books.
 521
 522 source kernel/Kconfig.preempt
 523
 524 source kernel/Kconfig.hz
 525
 526 config ARCH_RANDOM
 527         def_bool y
 528         prompt "s390 architectural random number generation API"
 529         help
 530           Enable the s390 architectural random number generation API
 531           to provide random data for all consumers within the Linux
 532           kernel.
 533
 534           When enabled the arch_random_* functions declared in linux/random.h
 535           are implemented. The implementation is based on the s390 CPACF
 536           instruction subfunction TRNG which provides a real true random
 537           number generator.
 538
 539           If unsure, say Y.
 540
 541 config ALTERNATIVES
 542         def_bool y
 543         prompt "Patch optimized instructions for running CPU type"
 544         help
 545           When enabled the kernel code is compiled with additional
 546           alternative instructions blocks optimized for newer CPU types.
 547           These alternative instructions blocks are patched at kernel boot
 548           time when running CPU supports them. This mechanism is used to
 549           optimize some critical code paths (i.e. spinlocks) for newer CPUs
 550           even if kernel is build to support older machine generations.
 551
 552           This mechanism could be disabled by appending "noaltinstr"
 553           option to the kernel command line.
 554
 555           If unsure, say Y.
 556
 557 endmenu
 558
 559 menu "Memory setup"
 560
 561 config ARCH_SPARSEMEM_ENABLE
 562         def_bool y
 563         select SPARSEMEM_VMEMMAP_ENABLE
 564         select SPARSEMEM_VMEMMAP
 565
 566 config ARCH_SPARSEMEM_DEFAULT
 567         def_bool y
 568
 569 config ARCH_SELECT_MEMORY_MODEL
 570         def_bool y
 571
 572 config ARCH_ENABLE_MEMORY_HOTPLUG
 573         def_bool y if SPARSEMEM
 574
 575 config ARCH_ENABLE_MEMORY_HOTREMOVE
 576         def_bool y
 577
 578 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
 579         def_bool y
 580
 581 config FORCE_MAX_ZONEORDER
 582         int
 583         default "9"
 584
 585 source "mm/Kconfig"
 586
 587 config MAX_PHYSMEM_BITS
 588         int "Maximum size of supported physical memory in bits (42-53)"
 589         range 42 53
 590         default "46"
 591         help
 592           This option specifies the maximum supported size of physical memory
 593           in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
 594           Increasing the number of bits also increases the kernel image size.
 595           By default 46 bits (64TB) are supported.
 596
 597 config PACK_STACK
 598         def_bool y
 599         prompt "Pack kernel stack"
 600         help
 601           This option enables the compiler option -mkernel-backchain if it
 602           is available. If the option is available the compiler supports
 603           the new stack layout which dramatically reduces the minimum stack
 604           frame size. With an old compiler a non-leaf function needs a
 605           minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
 606           -mkernel-backchain the minimum size drops to 16 byte on 31 bit
 607           and 24 byte on 64 bit.
 608
 609           Say Y if you are unsure.
 610
 611 config CHECK_STACK
 612         def_bool y
 613         prompt "Detect kernel stack overflow"
 614         help
 615           This option enables the compiler option -mstack-guard and
 616           -mstack-size if they are available. If the compiler supports them
 617           it will emit additional code to each function prolog to trigger
 618           an illegal operation if the kernel stack is about to overflow.
 619
 620           Say N if you are unsure.
 621
 622 config STACK_GUARD
 623         int "Size of the guard area (128-1024)"
 624         range 128 1024
 625         depends on CHECK_STACK
 626         default "256"
 627         help
 628           This allows you to specify the size of the guard area at the lower
 629           end of the kernel stack. If the kernel stack points into the guard
 630           area on function entry an illegal operation is triggered. The size
 631           needs to be a power of 2. Please keep in mind that the size of an
 632           interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
 633           The minimum size for the stack guard should be 256 for 31 bit and
 634           512 for 64 bit.
 635
 636 config WARN_DYNAMIC_STACK
 637         def_bool n
 638         prompt "Emit compiler warnings for function with dynamic stack usage"
 639         help
 640           This option enables the compiler option -mwarn-dynamicstack. If the
 641           compiler supports this options generates warnings for functions
 642           that dynamically allocate stack space using alloca.
 643
 644           Say N if you are unsure.
 645
 646 endmenu
 647
 648 menu "I/O subsystem"
 649
 650 config QDIO
 651         def_tristate y
 652         prompt "QDIO support"
 653         ---help---
 654           This driver provides the Queued Direct I/O base support for
 655           IBM System z.
 656
 657           To compile this driver as a module, choose M here: the
 658           module will be called qdio.
 659
 660           If unsure, say Y.
 661
 662 menuconfig PCI
 663         bool "PCI support"
 664         select PCI_MSI
 665         select IOMMU_SUPPORT
 666         help
 667           Enable PCI support.
 668
 669 if PCI
 670
 671 config PCI_NR_FUNCTIONS
 672         int "Maximum number of PCI functions (1-4096)"
 673         range 1 4096
 674         default "128"
 675         help
 676           This allows you to specify the maximum number of PCI functions which
 677           this kernel will support.
 678
 679 source "drivers/pci/Kconfig"
 680
 681 endif   # PCI
 682
 683 config PCI_DOMAINS
 684         def_bool PCI
 685
 686 config HAS_IOMEM
 687         def_bool PCI
 688
 689 config IOMMU_HELPER
 690         def_bool PCI
 691
 692 config NEED_SG_DMA_LENGTH
 693         def_bool PCI
 694
 695 config NEED_DMA_MAP_STATE
 696         def_bool PCI
 697
 698 config CHSC_SCH
 699         def_tristate m
 700         prompt "Support for CHSC subchannels"
 701         help
 702           This driver allows usage of CHSC subchannels. A CHSC subchannel
 703           is usually present on LPAR only.
 704           The driver creates a device /dev/chsc, which may be used to
 705           obtain I/O configuration information about the machine and
 706           to issue asynchronous chsc commands (DANGEROUS).
 707           You will usually only want to use this interface on a special
 708           LPAR designated for system management.
 709
 710           To compile this driver as a module, choose M here: the
 711           module will be called chsc_sch.
 712
 713           If unsure, say N.
 714
 715 config SCM_BUS
 716         def_bool y
 717         prompt "SCM bus driver"
 718         help
 719           Bus driver for Storage Class Memory.
 720
 721 config EADM_SCH
 722         def_tristate m
 723         prompt "Support for EADM subchannels"
 724         depends on SCM_BUS
 725         help
 726           This driver allows usage of EADM subchannels. EADM subchannels act
 727           as a communication vehicle for SCM increments.
 728
 729           To compile this driver as a module, choose M here: the
 730           module will be called eadm_sch.
 731
 732 config VFIO_CCW
 733         def_tristate n
 734         prompt "Support for VFIO-CCW subchannels"
 735         depends on S390_CCW_IOMMU && VFIO_MDEV
 736         help
 737           This driver allows usage of I/O subchannels via VFIO-CCW.
 738
 739           To compile this driver as a module, choose M here: the
 740           module will be called vfio_ccw.
 741
 742 endmenu
 743
 744 menu "Dump support"
 745
 746 config CRASH_DUMP
 747         bool "kernel crash dumps"
 748         depends on SMP
 749         select KEXEC
 750         help
 751           Generate crash dump after being started by kexec.
 752           Crash dump kernels are loaded in the main kernel with kexec-tools
 753           into a specially reserved region and then later executed after
 754           a crash by kdump/kexec.
 755           Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
 756           This option also enables s390 zfcpdump.
 757           See also <file:Documentation/s390/zfcpdump.txt>
 758
 759 endmenu
 760
 761 menu "Executable file formats / Emulations"
 762
 763 source "fs/Kconfig.binfmt"
 764
 765 config SECCOMP
 766         def_bool y
 767         prompt "Enable seccomp to safely compute untrusted bytecode"
 768         depends on PROC_FS
 769         help
 770           This kernel feature is useful for number crunching applications
 771           that may need to compute untrusted bytecode during their
 772           execution. By using pipes or other transports made available to
 773           the process as file descriptors supporting the read/write
 774           syscalls, it's possible to isolate those applications in
 775           their own address space using seccomp. Once seccomp is
 776           enabled via /proc/<pid>/seccomp, it cannot be disabled
 777           and the task is only allowed to execute a few safe syscalls
 778           defined by each seccomp mode.
 779
 780           If unsure, say Y.
 781
 782 endmenu
 783
 784 menu "Power Management"
 785
 786 config ARCH_HIBERNATION_POSSIBLE
 787         def_bool y
 788
 789 source "kernel/power/Kconfig"
 790
 791 endmenu
 792
 793 source "net/Kconfig"
 794
 795 config PCMCIA
 796         def_bool n
 797
 798 config CCW
 799         def_bool y
 800
 801 source "drivers/Kconfig"
 802
 803 source "fs/Kconfig"
 804
 805 source "arch/s390/Kconfig.debug"
 806
 807 source "security/Kconfig"
 808
 809 source "crypto/Kconfig"
 810
 811 source "lib/Kconfig"
 812
 813 menu "Virtualization"
 814
 815 config PFAULT
 816         def_bool y
 817         prompt "Pseudo page fault support"
 818         help
 819           Select this option, if you want to use PFAULT pseudo page fault
 820           handling under VM. If running native or in LPAR, this option
 821           has no effect. If your VM does not support PFAULT, PAGEEX
 822           pseudo page fault handling will be used.
 823           Note that VM 4.2 supports PFAULT but has a bug in its
 824           implementation that causes some problems.
 825           Everybody who wants to run Linux under VM != VM4.2 should select
 826           this option.
 827
 828 config CMM
 829         def_tristate n
 830         prompt "Cooperative memory management"
 831         help
 832           Select this option, if you want to enable the kernel interface
 833           to reduce the memory size of the system. This is accomplished
 834           by allocating pages of memory and put them "on hold". This only
 835           makes sense for a system running under VM where the unused pages
 836           will be reused by VM for other guest systems. The interface
 837           allows an external monitor to balance memory of many systems.
 838           Everybody who wants to run Linux under VM should select this
 839           option.
 840
 841 config CMM_IUCV
 842         def_bool y
 843         prompt "IUCV special message interface to cooperative memory management"
 844         depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
 845         help
 846           Select this option to enable the special message interface to
 847           the cooperative memory management.
 848
 849 config APPLDATA_BASE
 850         def_bool n
 851         prompt "Linux - VM Monitor Stream, base infrastructure"
 852         depends on PROC_FS
 853         help
 854           This provides a kernel interface for creating and updating z/VM APPLDATA
 855           monitor records. The monitor records are updated at certain time
 856           intervals, once the timer is started.
 857           Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
 858           i.e. enables or disables monitoring on the Linux side.
 859           A custom interval value (in seconds) can be written to
 860           /proc/appldata/interval.
 861
 862           Defaults are 60 seconds interval and timer off.
 863           The /proc entries can also be read from, showing the current settings.
 864
 865 config APPLDATA_MEM
 866         def_tristate m
 867         prompt "Monitor memory management statistics"
 868         depends on APPLDATA_BASE && VM_EVENT_COUNTERS
 869         help
 870           This provides memory management related data to the Linux - VM Monitor
 871           Stream, like paging/swapping rate, memory utilisation, etc.
 872           Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
 873           APPLDATA monitor record, i.e. enables or disables monitoring this record
 874           on the z/VM side.
 875
 876           Default is disabled.
 877           The /proc entry can also be read from, showing the current settings.
 878
 879           This can also be compiled as a module, which will be called
 880           appldata_mem.o.
 881
 882 config APPLDATA_OS
 883         def_tristate m
 884         prompt "Monitor OS statistics"
 885         depends on APPLDATA_BASE
 886         help
 887           This provides OS related data to the Linux - VM Monitor Stream, like
 888           CPU utilisation, etc.
 889           Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
 890           APPLDATA monitor record, i.e. enables or disables monitoring this record
 891           on the z/VM side.
 892
 893           Default is disabled.
 894           This can also be compiled as a module, which will be called
 895           appldata_os.o.
 896
 897 config APPLDATA_NET_SUM
 898         def_tristate m
 899         prompt "Monitor overall network statistics"
 900         depends on APPLDATA_BASE && NET
 901         help
 902           This provides network related data to the Linux - VM Monitor Stream,
 903           currently there is only a total sum of network I/O statistics, no
 904           per-interface data.
 905           Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
 906           APPLDATA monitor record, i.e. enables or disables monitoring this record
 907           on the z/VM side.
 908
 909           Default is disabled.
 910           This can also be compiled as a module, which will be called
 911           appldata_net_sum.o.
 912
 913 config S390_HYPFS_FS
 914         def_bool y
 915         prompt "s390 hypervisor file system support"
 916         select SYS_HYPERVISOR
 917         help
 918           This is a virtual file system intended to provide accounting
 919           information in an s390 hypervisor environment.
 920
 921 source "arch/s390/kvm/Kconfig"
 922
 923 config S390_GUEST
 924         def_bool y
 925         prompt "s390 support for virtio devices"
 926         select TTY
 927         select VIRTUALIZATION
 928         select VIRTIO
 929         select VIRTIO_CONSOLE
 930         help
 931           Enabling this option adds support for virtio based paravirtual device
 932           drivers on s390.
 933
 934           Select this option if you want to run the kernel as a guest under
 935           the KVM hypervisor.
 936
 937 endmenu