arch/s390/Kconfig

   1 config MMU
   2         def_bool y
   3
   4 config ZONE_DMA
   5         def_bool y
   6
   7 config LOCKDEP_SUPPORT
   8         def_bool y
   9
  10 config STACKTRACE_SUPPORT
  11         def_bool y
  12
  13 config HAVE_LATENCYTOP_SUPPORT
  14         def_bool y
  15
  16 config RWSEM_GENERIC_SPINLOCK
  17         bool
  18
  19 config RWSEM_XCHGADD_ALGORITHM
  20         def_bool y
  21
  22 config ARCH_HAS_ILOG2_U32
  23         def_bool n
  24
  25 config ARCH_HAS_ILOG2_U64
  26         def_bool n
  27
  28 config GENERIC_HWEIGHT
  29         def_bool y
  30
  31 config GENERIC_BUG
  32         def_bool y if BUG
  33
  34 config GENERIC_BUG_RELATIVE_POINTERS
  35         def_bool y
  36
  37 config ARCH_DMA_ADDR_T_64BIT
  38         def_bool y
  39
  40 config GENERIC_LOCKBREAK
  41         def_bool y if SMP && PREEMPT
  42
  43 config PGSTE
  44         def_bool y if KVM
  45
  46 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
  47         def_bool y
  48
  49 config KEXEC
  50         def_bool y
  51         select KEXEC_CORE
  52
  53 config AUDIT_ARCH
  54         def_bool y
  55
  56 config NO_IOPORT_MAP
  57         def_bool y
  58
  59 config PCI_QUIRKS
  60         def_bool n
  61
  62 config ARCH_SUPPORTS_UPROBES
  63         def_bool y
  64
  65 config S390
  66         def_bool y
  67         select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
  68         select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
  69         select ARCH_HAS_DEVMEM_IS_ALLOWED
  70         select ARCH_HAS_ELF_RANDOMIZE
  71         select ARCH_HAS_GCOV_PROFILE_ALL
  72         select ARCH_HAS_SG_CHAIN
  73         select ARCH_HAVE_NMI_SAFE_CMPXCHG
  74         select ARCH_INLINE_READ_LOCK
  75         select ARCH_INLINE_READ_LOCK_BH
  76         select ARCH_INLINE_READ_LOCK_IRQ
  77         select ARCH_INLINE_READ_LOCK_IRQSAVE
  78         select ARCH_INLINE_READ_TRYLOCK
  79         select ARCH_INLINE_READ_UNLOCK
  80         select ARCH_INLINE_READ_UNLOCK_BH
  81         select ARCH_INLINE_READ_UNLOCK_IRQ
  82         select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
  83         select ARCH_INLINE_SPIN_LOCK
  84         select ARCH_INLINE_SPIN_LOCK_BH
  85         select ARCH_INLINE_SPIN_LOCK_IRQ
  86         select ARCH_INLINE_SPIN_LOCK_IRQSAVE
  87         select ARCH_INLINE_SPIN_TRYLOCK
  88         select ARCH_INLINE_SPIN_TRYLOCK_BH
  89         select ARCH_INLINE_SPIN_UNLOCK
  90         select ARCH_INLINE_SPIN_UNLOCK_BH
  91         select ARCH_INLINE_SPIN_UNLOCK_IRQ
  92         select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
  93         select ARCH_INLINE_WRITE_LOCK
  94         select ARCH_INLINE_WRITE_LOCK_BH
  95         select ARCH_INLINE_WRITE_LOCK_IRQ
  96         select ARCH_INLINE_WRITE_LOCK_IRQSAVE
  97         select ARCH_INLINE_WRITE_TRYLOCK
  98         select ARCH_INLINE_WRITE_UNLOCK
  99         select ARCH_INLINE_WRITE_UNLOCK_BH
 100         select ARCH_INLINE_WRITE_UNLOCK_IRQ
 101         select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
 102         select ARCH_SAVE_PAGE_KEYS if HIBERNATION
 103         select ARCH_SUPPORTS_ATOMIC_RMW
 104         select ARCH_SUPPORTS_NUMA_BALANCING
 105         select ARCH_USE_BUILTIN_BSWAP
 106         select ARCH_USE_CMPXCHG_LOCKREF
 107         select ARCH_WANTS_PROT_NUMA_PROT_NONE
 108         select ARCH_WANT_IPC_PARSE_VERSION
 109         select BUILDTIME_EXTABLE_SORT
 110         select CLONE_BACKWARDS2
 111         select DYNAMIC_FTRACE if FUNCTION_TRACER
 112         select GENERIC_CLOCKEVENTS
 113         select GENERIC_CPU_AUTOPROBE
 114         select GENERIC_CPU_DEVICES if !SMP
 115         select GENERIC_FIND_FIRST_BIT
 116         select GENERIC_SMP_IDLE_THREAD
 117         select GENERIC_TIME_VSYSCALL
 118         select HAVE_ALIGNED_STRUCT_PAGE if SLUB
 119         select HAVE_ARCH_AUDITSYSCALL
 120         select HAVE_ARCH_EARLY_PFN_TO_NID
 121         select HAVE_ARCH_JUMP_LABEL
 122         select HAVE_ARCH_SECCOMP_FILTER
 123         select HAVE_ARCH_SOFT_DIRTY
 124         select HAVE_ARCH_TRACEHOOK
 125         select HAVE_ARCH_TRANSPARENT_HUGEPAGE
 126         select HAVE_BPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
 127         select HAVE_CMPXCHG_DOUBLE
 128         select HAVE_CMPXCHG_LOCAL
 129         select HAVE_DEBUG_KMEMLEAK
 130         select HAVE_DYNAMIC_FTRACE
 131         select HAVE_DYNAMIC_FTRACE_WITH_REGS
 132         select HAVE_FTRACE_MCOUNT_RECORD
 133         select HAVE_FUNCTION_GRAPH_TRACER
 134         select HAVE_FUNCTION_TRACER
 135         select HAVE_FUTEX_CMPXCHG if FUTEX
 136         select HAVE_KERNEL_BZIP2
 137         select HAVE_KERNEL_GZIP
 138         select HAVE_KERNEL_LZ4
 139         select HAVE_KERNEL_LZMA
 140         select HAVE_KERNEL_LZO
 141         select HAVE_KERNEL_XZ
 142         select HAVE_KPROBES
 143         select HAVE_KRETPROBES
 144         select HAVE_KVM
 145         select HAVE_LIVEPATCH
 146         select HAVE_MEMBLOCK
 147         select HAVE_MEMBLOCK_NODE_MAP
 148         select HAVE_MEMBLOCK_PHYS_MAP
 149         select HAVE_MOD_ARCH_SPECIFIC
 150         select HAVE_OPROFILE
 151         select HAVE_PERF_EVENTS
 152         select HAVE_REGS_AND_STACK_ACCESS_API
 153         select HAVE_SYSCALL_TRACEPOINTS
 154         select HAVE_VIRT_CPU_ACCOUNTING
 155         select MODULES_USE_ELF_RELA
 156         select NO_BOOTMEM
 157         select OLD_SIGACTION
 158         select OLD_SIGSUSPEND3
 159         select SYSCTL_EXCEPTION_TRACE
 160         select TTY
 161         select VIRT_CPU_ACCOUNTING
 162         select VIRT_TO_BUS
 163
 164
 165 config SCHED_OMIT_FRAME_POINTER
 166         def_bool y
 167
 168 config PGTABLE_LEVELS
 169         int
 170         default 4
 171
 172 source "init/Kconfig"
 173
 174 source "kernel/Kconfig.freezer"
 175
 176 source "kernel/livepatch/Kconfig"
 177
 178 menu "Processor type and features"
 179
 180 config HAVE_MARCH_Z900_FEATURES
 181         def_bool n
 182
 183 config HAVE_MARCH_Z990_FEATURES
 184         def_bool n
 185         select HAVE_MARCH_Z900_FEATURES
 186
 187 config HAVE_MARCH_Z9_109_FEATURES
 188         def_bool n
 189         select HAVE_MARCH_Z990_FEATURES
 190
 191 config HAVE_MARCH_Z10_FEATURES
 192         def_bool n
 193         select HAVE_MARCH_Z9_109_FEATURES
 194
 195 config HAVE_MARCH_Z196_FEATURES
 196         def_bool n
 197         select HAVE_MARCH_Z10_FEATURES
 198
 199 config HAVE_MARCH_ZEC12_FEATURES
 200         def_bool n
 201         select HAVE_MARCH_Z196_FEATURES
 202
 203 config HAVE_MARCH_Z13_FEATURES
 204         def_bool n
 205         select HAVE_MARCH_ZEC12_FEATURES
 206
 207 choice
 208         prompt "Processor type"
 209         default MARCH_Z900
 210
 211 config MARCH_Z900
 212         bool "IBM zSeries model z800 and z900"
 213         select HAVE_MARCH_Z900_FEATURES
 214         help
 215           Select this to enable optimizations for model z800/z900 (2064 and
 216           2066 series). This will enable some optimizations that are not
 217           available on older ESA/390 (31 Bit) only CPUs.
 218
 219 config MARCH_Z990
 220         bool "IBM zSeries model z890 and z990"
 221         select HAVE_MARCH_Z990_FEATURES
 222         help
 223           Select this to enable optimizations for model z890/z990 (2084 and
 224           2086 series). The kernel will be slightly faster but will not work
 225           on older machines.
 226
 227 config MARCH_Z9_109
 228         bool "IBM System z9"
 229         select HAVE_MARCH_Z9_109_FEATURES
 230         help
 231           Select this to enable optimizations for IBM System z9 (2094 and
 232           2096 series). The kernel will be slightly faster but will not work
 233           on older machines.
 234
 235 config MARCH_Z10
 236         bool "IBM System z10"
 237         select HAVE_MARCH_Z10_FEATURES
 238         help
 239           Select this to enable optimizations for IBM System z10 (2097 and
 240           2098 series). The kernel will be slightly faster but will not work
 241           on older machines.
 242
 243 config MARCH_Z196
 244         bool "IBM zEnterprise 114 and 196"
 245         select HAVE_MARCH_Z196_FEATURES
 246         help
 247           Select this to enable optimizations for IBM zEnterprise 114 and 196
 248           (2818 and 2817 series). The kernel will be slightly faster but will
 249           not work on older machines.
 250
 251 config MARCH_ZEC12
 252         bool "IBM zBC12 and zEC12"
 253         select HAVE_MARCH_ZEC12_FEATURES
 254         help
 255           Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
 256           2827 series). The kernel will be slightly faster but will not work on
 257           older machines.
 258
 259 config MARCH_Z13
 260         bool "IBM z13"
 261         select HAVE_MARCH_Z13_FEATURES
 262         help
 263           Select this to enable optimizations for IBM z13 (2964 series).
 264           The kernel will be slightly faster but will not work on older
 265           machines.
 266
 267 endchoice
 268
 269 config MARCH_Z900_TUNE
 270         def_bool TUNE_Z900 || MARCH_Z900 && TUNE_DEFAULT
 271
 272 config MARCH_Z990_TUNE
 273         def_bool TUNE_Z990 || MARCH_Z990 && TUNE_DEFAULT
 274
 275 config MARCH_Z9_109_TUNE
 276         def_bool TUNE_Z9_109 || MARCH_Z9_109 && TUNE_DEFAULT
 277
 278 config MARCH_Z10_TUNE
 279         def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
 280
 281 config MARCH_Z196_TUNE
 282         def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
 283
 284 config MARCH_ZEC12_TUNE
 285         def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
 286
 287 config MARCH_Z13_TUNE
 288         def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
 289
 290 choice
 291         prompt "Tune code generation"
 292         default TUNE_DEFAULT
 293         help
 294           Cause the compiler to tune (-mtune) the generated code for a machine.
 295           This will make the code run faster on the selected machine but
 296           somewhat slower on other machines.
 297           This option only changes how the compiler emits instructions, not the
 298           selection of instructions itself, so the resulting kernel will run on
 299           all other machines.
 300
 301 config TUNE_DEFAULT
 302         bool "Default"
 303         help
 304           Tune the generated code for the target processor for which the kernel
 305           will be compiled.
 306
 307 config TUNE_Z900
 308         bool "IBM zSeries model z800 and z900"
 309
 310 config TUNE_Z990
 311         bool "IBM zSeries model z890 and z990"
 312
 313 config TUNE_Z9_109
 314         bool "IBM System z9"
 315
 316 config TUNE_Z10
 317         bool "IBM System z10"
 318
 319 config TUNE_Z196
 320         bool "IBM zEnterprise 114 and 196"
 321
 322 config TUNE_ZEC12
 323         bool "IBM zBC12 and zEC12"
 324
 325 config TUNE_Z13
 326         bool "IBM z13"
 327
 328 endchoice
 329
 330 config 64BIT
 331         def_bool y
 332
 333 config COMPAT
 334         def_bool y
 335         prompt "Kernel support for 31 bit emulation"
 336         select COMPAT_BINFMT_ELF if BINFMT_ELF
 337         select ARCH_WANT_OLD_COMPAT_IPC
 338         select COMPAT_OLD_SIGACTION
 339         depends on MULTIUSER
 340         help
 341           Select this option if you want to enable your system kernel to
 342           handle system-calls from ELF binaries for 31 bit ESA.  This option
 343           (and some other stuff like libraries and such) is needed for
 344           executing 31 bit applications.  It is safe to say "Y".
 345
 346 config SYSVIPC_COMPAT
 347         def_bool y if COMPAT && SYSVIPC
 348
 349 config KEYS_COMPAT
 350         def_bool y if COMPAT && KEYS
 351
 352 config SMP
 353         def_bool y
 354         prompt "Symmetric multi-processing support"
 355         ---help---
 356           This enables support for systems with more than one CPU. If you have
 357           a system with only one CPU, like most personal computers, say N. If
 358           you have a system with more than one CPU, say Y.
 359
 360           If you say N here, the kernel will run on uni- and multiprocessor
 361           machines, but will use only one CPU of a multiprocessor machine. If
 362           you say Y here, the kernel will run on many, but not all,
 363           uniprocessor machines. On a uniprocessor machine, the kernel
 364           will run faster if you say N here.
 365
 366           See also the SMP-HOWTO available at
 367           <http://www.tldp.org/docs.html#howto>.
 368
 369           Even if you don't know what to do here, say Y.
 370
 371 config NR_CPUS
 372         int "Maximum number of CPUs (2-512)"
 373         range 2 512
 374         depends on SMP
 375         default "64"
 376         help
 377           This allows you to specify the maximum number of CPUs which this
 378           kernel will support. The maximum supported value is 512 and the
 379           minimum value which makes sense is 2.
 380
 381           This is purely to save memory - each supported CPU adds
 382           approximately sixteen kilobytes to the kernel image.
 383
 384 config HOTPLUG_CPU
 385         def_bool y
 386         prompt "Support for hot-pluggable CPUs"
 387         depends on SMP
 388         help
 389           Say Y here to be able to turn CPUs off and on. CPUs
 390           can be controlled through /sys/devices/system/cpu/cpu#.
 391           Say N if you want to disable CPU hotplug.
 392
 393 # Some NUMA nodes have memory ranges that span
 394 # other nodes.  Even though a pfn is valid and
 395 # between a node's start and end pfns, it may not
 396 # reside on that node.  See memmap_init_zone()
 397 # for details. <- They meant memory holes!
 398 config NODES_SPAN_OTHER_NODES
 399         def_bool NUMA
 400
 401 config NUMA
 402         bool "NUMA support"
 403         depends on SMP && SCHED_TOPOLOGY
 404         default n
 405         help
 406           Enable NUMA support
 407
 408           This option adds NUMA support to the kernel.
 409
 410           An operation mode can be selected by appending
 411           numa=<method> to the kernel command line.
 412
 413           The default behaviour is identical to appending numa=plain to
 414           the command line. This will create just one node with all
 415           available memory and all CPUs in it.
 416
 417 config NODES_SHIFT
 418         int "Maximum NUMA nodes (as a power of 2)"
 419         range 1 10
 420         depends on NUMA
 421         default "4"
 422         help
 423           Specify the maximum number of NUMA nodes available on the target
 424           system. Increases memory reserved to accommodate various tables.
 425
 426 menu "Select NUMA modes"
 427         depends on NUMA
 428
 429 config NUMA_EMU
 430         bool "NUMA emulation"
 431         default y
 432         help
 433           Numa emulation mode will split the available system memory into
 434           equal chunks which then are distributed over the configured number
 435           of nodes in a round-robin manner.
 436
 437           The number of fake nodes is limited by the number of available memory
 438           chunks (i.e. memory size / fake size) and the number of supported
 439           nodes in the kernel.
 440
 441           The CPUs are assigned to the nodes in a way that partially respects
 442           the original machine topology (if supported by the machine).
 443           Fair distribution of the CPUs is not guaranteed.
 444
 445 config EMU_SIZE
 446         hex "NUMA emulation memory chunk size"
 447         default 0x10000000
 448         range 0x400000 0x100000000
 449         depends on NUMA_EMU
 450         help
 451           Select the default size by which the memory is chopped and then
 452           assigned to emulated NUMA nodes.
 453
 454           This can be overridden by specifying
 455
 456           emu_size=<n>
 457
 458           on the kernel command line where also suffixes K, M, G, and T are
 459           supported.
 460
 461 endmenu
 462
 463 config SCHED_SMT
 464         def_bool n
 465
 466 config SCHED_MC
 467         def_bool n
 468
 469 config SCHED_BOOK
 470         def_bool n
 471
 472 config SCHED_TOPOLOGY
 473         def_bool y
 474         prompt "Topology scheduler support"
 475         depends on SMP
 476         select SCHED_SMT
 477         select SCHED_MC
 478         select SCHED_BOOK
 479         help
 480           Topology scheduler support improves the CPU scheduler's decision
 481           making when dealing with machines that have multi-threading,
 482           multiple cores or multiple books.
 483
 484 source kernel/Kconfig.preempt
 485
 486 source kernel/Kconfig.hz
 487
 488 endmenu
 489
 490 menu "Memory setup"
 491
 492 config ARCH_SPARSEMEM_ENABLE
 493         def_bool y
 494         select SPARSEMEM_VMEMMAP_ENABLE
 495         select SPARSEMEM_VMEMMAP
 496
 497 config ARCH_SPARSEMEM_DEFAULT
 498         def_bool y
 499
 500 config ARCH_SELECT_MEMORY_MODEL
 501         def_bool y
 502
 503 config ARCH_ENABLE_MEMORY_HOTPLUG
 504         def_bool y if SPARSEMEM
 505
 506 config ARCH_ENABLE_MEMORY_HOTREMOVE
 507         def_bool y
 508
 509 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
 510         def_bool y
 511
 512 config FORCE_MAX_ZONEORDER
 513         int
 514         default "9"
 515
 516 source "mm/Kconfig"
 517
 518 config PACK_STACK
 519         def_bool y
 520         prompt "Pack kernel stack"
 521         help
 522           This option enables the compiler option -mkernel-backchain if it
 523           is available. If the option is available the compiler supports
 524           the new stack layout which dramatically reduces the minimum stack
 525           frame size. With an old compiler a non-leaf function needs a
 526           minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
 527           -mkernel-backchain the minimum size drops to 16 byte on 31 bit
 528           and 24 byte on 64 bit.
 529
 530           Say Y if you are unsure.
 531
 532 config CHECK_STACK
 533         def_bool y
 534         prompt "Detect kernel stack overflow"
 535         help
 536           This option enables the compiler option -mstack-guard and
 537           -mstack-size if they are available. If the compiler supports them
 538           it will emit additional code to each function prolog to trigger
 539           an illegal operation if the kernel stack is about to overflow.
 540
 541           Say N if you are unsure.
 542
 543 config STACK_GUARD
 544         int "Size of the guard area (128-1024)"
 545         range 128 1024
 546         depends on CHECK_STACK
 547         default "256"
 548         help
 549           This allows you to specify the size of the guard area at the lower
 550           end of the kernel stack. If the kernel stack points into the guard
 551           area on function entry an illegal operation is triggered. The size
 552           needs to be a power of 2. Please keep in mind that the size of an
 553           interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
 554           The minimum size for the stack guard should be 256 for 31 bit and
 555           512 for 64 bit.
 556
 557 config WARN_DYNAMIC_STACK
 558         def_bool n
 559         prompt "Emit compiler warnings for function with dynamic stack usage"
 560         help
 561           This option enables the compiler option -mwarn-dynamicstack. If the
 562           compiler supports this options generates warnings for functions
 563           that dynamically allocate stack space using alloca.
 564
 565           Say N if you are unsure.
 566
 567 endmenu
 568
 569 menu "I/O subsystem"
 570
 571 config QDIO
 572         def_tristate y
 573         prompt "QDIO support"
 574         ---help---
 575           This driver provides the Queued Direct I/O base support for
 576           IBM System z.
 577
 578           To compile this driver as a module, choose M here: the
 579           module will be called qdio.
 580
 581           If unsure, say Y.
 582
 583 menuconfig PCI
 584         bool "PCI support"
 585         select HAVE_DMA_ATTRS
 586         select PCI_MSI
 587         select IOMMU_SUPPORT
 588         help
 589           Enable PCI support.
 590
 591 if PCI
 592
 593 config PCI_NR_FUNCTIONS
 594         int "Maximum number of PCI functions (1-4096)"
 595         range 1 4096
 596         default "64"
 597         help
 598           This allows you to specify the maximum number of PCI functions which
 599           this kernel will support.
 600
 601 config PCI_NR_MSI
 602         int "Maximum number of MSI interrupts (64-32768)"
 603         range 64 32768
 604         default "256"
 605         help
 606           This defines the number of virtual interrupts the kernel will
 607           provide for MSI interrupts. If you configure your system to have
 608           too few drivers will fail to allocate MSI interrupts for all
 609           PCI devices.
 610
 611 source "drivers/pci/Kconfig"
 612 source "drivers/pci/pcie/Kconfig"
 613 source "drivers/pci/hotplug/Kconfig"
 614
 615 endif   # PCI
 616
 617 config PCI_DOMAINS
 618         def_bool PCI
 619
 620 config HAS_IOMEM
 621         def_bool PCI
 622
 623 config IOMMU_HELPER
 624         def_bool PCI
 625
 626 config HAS_DMA
 627         def_bool PCI
 628         select HAVE_DMA_API_DEBUG
 629
 630 config NEED_SG_DMA_LENGTH
 631         def_bool PCI
 632
 633 config NEED_DMA_MAP_STATE
 634         def_bool PCI
 635
 636 config CHSC_SCH
 637         def_tristate m
 638         prompt "Support for CHSC subchannels"
 639         help
 640           This driver allows usage of CHSC subchannels. A CHSC subchannel
 641           is usually present on LPAR only.
 642           The driver creates a device /dev/chsc, which may be used to
 643           obtain I/O configuration information about the machine and
 644           to issue asynchronous chsc commands (DANGEROUS).
 645           You will usually only want to use this interface on a special
 646           LPAR designated for system management.
 647
 648           To compile this driver as a module, choose M here: the
 649           module will be called chsc_sch.
 650
 651           If unsure, say N.
 652
 653 config SCM_BUS
 654         def_bool y
 655         prompt "SCM bus driver"
 656         help
 657           Bus driver for Storage Class Memory.
 658
 659 config EADM_SCH
 660         def_tristate m
 661         prompt "Support for EADM subchannels"
 662         depends on SCM_BUS
 663         help
 664           This driver allows usage of EADM subchannels. EADM subchannels act
 665           as a communication vehicle for SCM increments.
 666
 667           To compile this driver as a module, choose M here: the
 668           module will be called eadm_sch.
 669
 670 endmenu
 671
 672 menu "Dump support"
 673
 674 config CRASH_DUMP
 675         bool "kernel crash dumps"
 676         depends on SMP
 677         select KEXEC
 678         help
 679           Generate crash dump after being started by kexec.
 680           Crash dump kernels are loaded in the main kernel with kexec-tools
 681           into a specially reserved region and then later executed after
 682           a crash by kdump/kexec.
 683           Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
 684           This option also enables s390 zfcpdump.
 685           See also <file:Documentation/s390/zfcpdump.txt>
 686
 687 endmenu
 688
 689 menu "Executable file formats / Emulations"
 690
 691 source "fs/Kconfig.binfmt"
 692
 693 config SECCOMP
 694         def_bool y
 695         prompt "Enable seccomp to safely compute untrusted bytecode"
 696         depends on PROC_FS
 697         help
 698           This kernel feature is useful for number crunching applications
 699           that may need to compute untrusted bytecode during their
 700           execution. By using pipes or other transports made available to
 701           the process as file descriptors supporting the read/write
 702           syscalls, it's possible to isolate those applications in
 703           their own address space using seccomp. Once seccomp is
 704           enabled via /proc/<pid>/seccomp, it cannot be disabled
 705           and the task is only allowed to execute a few safe syscalls
 706           defined by each seccomp mode.
 707
 708           If unsure, say Y.
 709
 710 endmenu
 711
 712 menu "Power Management"
 713
 714 config ARCH_HIBERNATION_POSSIBLE
 715         def_bool y
 716
 717 source "kernel/power/Kconfig"
 718
 719 endmenu
 720
 721 source "net/Kconfig"
 722
 723 config PCMCIA
 724         def_bool n
 725
 726 config CCW
 727         def_bool y
 728
 729 source "drivers/Kconfig"
 730
 731 source "fs/Kconfig"
 732
 733 source "arch/s390/Kconfig.debug"
 734
 735 source "security/Kconfig"
 736
 737 source "crypto/Kconfig"
 738
 739 source "lib/Kconfig"
 740
 741 menu "Virtualization"
 742
 743 config PFAULT
 744         def_bool y
 745         prompt "Pseudo page fault support"
 746         help
 747           Select this option, if you want to use PFAULT pseudo page fault
 748           handling under VM. If running native or in LPAR, this option
 749           has no effect. If your VM does not support PFAULT, PAGEEX
 750           pseudo page fault handling will be used.
 751           Note that VM 4.2 supports PFAULT but has a bug in its
 752           implementation that causes some problems.
 753           Everybody who wants to run Linux under VM != VM4.2 should select
 754           this option.
 755
 756 config SHARED_KERNEL
 757         bool "VM shared kernel support"
 758         depends on !JUMP_LABEL
 759         help
 760           Select this option, if you want to share the text segment of the
 761           Linux kernel between different VM guests. This reduces memory
 762           usage with lots of guests but greatly increases kernel size.
 763           Also if a kernel was IPL'ed from a shared segment the kexec system
 764           call will not work.
 765           You should only select this option if you know what you are
 766           doing and want to exploit this feature.
 767
 768 config CMM
 769         def_tristate n
 770         prompt "Cooperative memory management"
 771         help
 772           Select this option, if you want to enable the kernel interface
 773           to reduce the memory size of the system. This is accomplished
 774           by allocating pages of memory and put them "on hold". This only
 775           makes sense for a system running under VM where the unused pages
 776           will be reused by VM for other guest systems. The interface
 777           allows an external monitor to balance memory of many systems.
 778           Everybody who wants to run Linux under VM should select this
 779           option.
 780
 781 config CMM_IUCV
 782         def_bool y
 783         prompt "IUCV special message interface to cooperative memory management"
 784         depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
 785         help
 786           Select this option to enable the special message interface to
 787           the cooperative memory management.
 788
 789 config APPLDATA_BASE
 790         def_bool n
 791         prompt "Linux - VM Monitor Stream, base infrastructure"
 792         depends on PROC_FS
 793         help
 794           This provides a kernel interface for creating and updating z/VM APPLDATA
 795           monitor records. The monitor records are updated at certain time
 796           intervals, once the timer is started.
 797           Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
 798           i.e. enables or disables monitoring on the Linux side.
 799           A custom interval value (in seconds) can be written to
 800           /proc/appldata/interval.
 801
 802           Defaults are 60 seconds interval and timer off.
 803           The /proc entries can also be read from, showing the current settings.
 804
 805 config APPLDATA_MEM
 806         def_tristate m
 807         prompt "Monitor memory management statistics"
 808         depends on APPLDATA_BASE && VM_EVENT_COUNTERS
 809         help
 810           This provides memory management related data to the Linux - VM Monitor
 811           Stream, like paging/swapping rate, memory utilisation, etc.
 812           Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
 813           APPLDATA monitor record, i.e. enables or disables monitoring this record
 814           on the z/VM side.
 815
 816           Default is disabled.
 817           The /proc entry can also be read from, showing the current settings.
 818
 819           This can also be compiled as a module, which will be called
 820           appldata_mem.o.
 821
 822 config APPLDATA_OS
 823         def_tristate m
 824         prompt "Monitor OS statistics"
 825         depends on APPLDATA_BASE
 826         help
 827           This provides OS related data to the Linux - VM Monitor Stream, like
 828           CPU utilisation, etc.
 829           Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
 830           APPLDATA monitor record, i.e. enables or disables monitoring this record
 831           on the z/VM side.
 832
 833           Default is disabled.
 834           This can also be compiled as a module, which will be called
 835           appldata_os.o.
 836
 837 config APPLDATA_NET_SUM
 838         def_tristate m
 839         prompt "Monitor overall network statistics"
 840         depends on APPLDATA_BASE && NET
 841         help
 842           This provides network related data to the Linux - VM Monitor Stream,
 843           currently there is only a total sum of network I/O statistics, no
 844           per-interface data.
 845           Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
 846           APPLDATA monitor record, i.e. enables or disables monitoring this record
 847           on the z/VM side.
 848
 849           Default is disabled.
 850           This can also be compiled as a module, which will be called
 851           appldata_net_sum.o.
 852
 853 config S390_HYPFS_FS
 854         def_bool y
 855         prompt "s390 hypervisor file system support"
 856         select SYS_HYPERVISOR
 857         help
 858           This is a virtual file system intended to provide accounting
 859           information in an s390 hypervisor environment.
 860
 861 source "arch/s390/kvm/Kconfig"
 862
 863 config S390_GUEST
 864         def_bool y
 865         prompt "s390 support for virtio devices"
 866         select TTY
 867         select VIRTUALIZATION
 868         select VIRTIO
 869         select VIRTIO_CONSOLE
 870         help
 871           Enabling this option adds support for virtio based paravirtual device
 872           drivers on s390.
 873
 874           Select this option if you want to run the kernel as a guest under
 875           the KVM hypervisor.
 876
 877 endmenu