arch/s390/Kconfig

   1 #
   2 # For a description of the syntax of this configuration file,
   3 # see Documentation/kbuild/kconfig-language.txt.
   4 #
   5
   6 config SCHED_MC
   7         def_bool y
   8         depends on SMP
   9
  10 config MMU
  11         def_bool y
  12
  13 config ZONE_DMA
  14         def_bool y
  15         depends on 64BIT
  16
  17 config LOCKDEP_SUPPORT
  18         def_bool y
  19
  20 config STACKTRACE_SUPPORT
  21         def_bool y
  22
  23 config HAVE_LATENCYTOP_SUPPORT
  24         def_bool y
  25
  26 config RWSEM_GENERIC_SPINLOCK
  27         bool
  28
  29 config RWSEM_XCHGADD_ALGORITHM
  30         def_bool y
  31
  32 config ARCH_HAS_ILOG2_U32
  33         bool
  34         default n
  35
  36 config ARCH_HAS_ILOG2_U64
  37         bool
  38         default n
  39
  40 config GENERIC_HWEIGHT
  41         def_bool y
  42
  43 config GENERIC_TIME
  44         def_bool y
  45
  46 config GENERIC_CLOCKEVENTS
  47         def_bool y
  48
  49 config GENERIC_BUG
  50         bool
  51         depends on BUG
  52         default y
  53
  54 config NO_IOMEM
  55         def_bool y
  56
  57 config NO_DMA
  58         def_bool y
  59
  60 config GENERIC_LOCKBREAK
  61         bool
  62         default y
  63         depends on SMP && PREEMPT
  64
  65 config PGSTE
  66         bool
  67         default y if KVM
  68
  69 mainmenu "Linux Kernel Configuration"
  70
  71 config S390
  72         def_bool y
  73         select HAVE_OPROFILE
  74         select HAVE_KPROBES
  75         select HAVE_KRETPROBES
  76         select HAVE_KVM if 64BIT
  77         select HAVE_ARCH_TRACEHOOK
  78
  79 source "init/Kconfig"
  80
  81 source "kernel/Kconfig.freezer"
  82
  83 menu "Base setup"
  84
  85 comment "Processor type and features"
  86
  87 source "kernel/time/Kconfig"
  88
  89 config 64BIT
  90         bool "64 bit kernel"
  91         help
  92           Select this option if you have a 64 bit IBM zSeries machine
  93           and want to use the 64 bit addressing mode.
  94
  95 config 32BIT
  96         bool
  97         default y if !64BIT
  98
  99 config SMP
 100         bool "Symmetric multi-processing support"
 101         ---help---
 102           This enables support for systems with more than one CPU. If you have
 103           a system with only one CPU, like most personal computers, say N. If
 104           you have a system with more than one CPU, say Y.
 105
 106           If you say N here, the kernel will run on single and multiprocessor
 107           machines, but will use only one CPU of a multiprocessor machine. If
 108           you say Y here, the kernel will run on many, but not all,
 109           singleprocessor machines. On a singleprocessor machine, the kernel
 110           will run faster if you say N here.
 111
 112           See also the SMP-HOWTO available at
 113           <http://www.tldp.org/docs.html#howto>.
 114
 115           Even if you don't know what to do here, say Y.
 116
 117 config NR_CPUS
 118         int "Maximum number of CPUs (2-64)"
 119         range 2 64
 120         depends on SMP
 121         default "32" if !64BIT
 122         default "64" if 64BIT
 123         help
 124           This allows you to specify the maximum number of CPUs which this
 125           kernel will support.  The maximum supported value is 64 and the
 126           minimum value which makes sense is 2.
 127
 128           This is purely to save memory - each supported CPU adds
 129           approximately sixteen kilobytes to the kernel image.
 130
 131 config HOTPLUG_CPU
 132         bool "Support for hot-pluggable CPUs"
 133         depends on SMP
 134         select HOTPLUG
 135         default n
 136         help
 137           Say Y here to be able to turn CPUs off and on. CPUs
 138           can be controlled through /sys/devices/system/cpu/cpu#.
 139           Say N if you want to disable CPU hotplug.
 140
 141 config MATHEMU
 142         bool "IEEE FPU emulation"
 143         depends on MARCH_G5
 144         help
 145           This option is required for IEEE compliant floating point arithmetic
 146           on older S/390 machines. Say Y unless you know your machine doesn't
 147           need this.
 148
 149 config COMPAT
 150         bool "Kernel support for 31 bit emulation"
 151         depends on 64BIT
 152         select COMPAT_BINFMT_ELF
 153         help
 154           Select this option if you want to enable your system kernel to
 155           handle system-calls from ELF binaries for 31 bit ESA.  This option
 156           (and some other stuff like libraries and such) is needed for
 157           executing 31 bit applications.  It is safe to say "Y".
 158
 159 config SYSVIPC_COMPAT
 160         bool
 161         depends on COMPAT && SYSVIPC
 162         default y
 163
 164 config AUDIT_ARCH
 165         bool
 166         default y
 167
 168 config S390_SWITCH_AMODE
 169         bool "Switch kernel/user addressing modes"
 170         help
 171           This option allows to switch the addressing modes of kernel and user
 172           space. The kernel parameter switch_amode=on will enable this feature,
 173           default is disabled. Enabling this (via kernel parameter) on machines
 174           earlier than IBM System z9-109 EC/BC will reduce system performance.
 175
 176           Note that this option will also be selected by selecting the execute
 177           protection option below. Enabling the execute protection via the
 178           noexec kernel parameter will also switch the addressing modes,
 179           independent of the switch_amode kernel parameter.
 180
 181
 182 config S390_EXEC_PROTECT
 183         bool "Data execute protection"
 184         select S390_SWITCH_AMODE
 185         help
 186           This option allows to enable a buffer overflow protection for user
 187           space programs and it also selects the addressing mode option above.
 188           The kernel parameter noexec=on will enable this feature and also
 189           switch the addressing modes, default is disabled. Enabling this (via
 190           kernel parameter) on machines earlier than IBM System z9-109 EC/BC
 191           will reduce system performance.
 192
 193 comment "Code generation options"
 194
 195 choice
 196         prompt "Processor type"
 197         default MARCH_G5
 198
 199 config MARCH_G5
 200         bool "S/390 model G5 and G6"
 201         depends on !64BIT
 202         help
 203           Select this to build a 31 bit kernel that works
 204           on all S/390 and zSeries machines.
 205
 206 config MARCH_Z900
 207         bool "IBM eServer zSeries model z800 and z900"
 208         help
 209           Select this to optimize for zSeries machines. This
 210           will enable some optimizations that are not available
 211           on older 31 bit only CPUs.
 212
 213 config MARCH_Z990
 214         bool "IBM eServer zSeries model z890 and z990"
 215         help
 216           Select this enable optimizations for model z890/z990.
 217           This will be slightly faster but does not work on
 218           older machines such as the z900.
 219
 220 config MARCH_Z9_109
 221         bool "IBM System z9"
 222         help
 223           Select this to enable optimizations for IBM System z9-109, IBM
 224           System z9 Enterprise Class (z9 EC), and IBM System z9 Business
 225           Class (z9 BC). The kernel will be slightly faster but will not
 226           work on older machines such as the z990, z890, z900, and z800.
 227
 228 endchoice
 229
 230 config PACK_STACK
 231         bool "Pack kernel stack"
 232         help
 233           This option enables the compiler option -mkernel-backchain if it
 234           is available. If the option is available the compiler supports
 235           the new stack layout which dramatically reduces the minimum stack
 236           frame size. With an old compiler a non-leaf function needs a
 237           minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
 238           -mkernel-backchain the minimum size drops to 16 byte on 31 bit
 239           and 24 byte on 64 bit.
 240
 241           Say Y if you are unsure.
 242
 243 config SMALL_STACK
 244         bool "Use 4kb/8kb for kernel stack instead of 8kb/16kb"
 245         depends on PACK_STACK && !LOCKDEP
 246         help
 247           If you say Y here and the compiler supports the -mkernel-backchain
 248           option the kernel will use a smaller kernel stack size. For 31 bit
 249           the reduced size is 4kb instead of 8kb and for 64 bit it is 8kb
 250           instead of 16kb. This allows to run more thread on a system and
 251           reduces the pressure on the memory management for higher order
 252           page allocations.
 253
 254           Say N if you are unsure.
 255
 256
 257 config CHECK_STACK
 258         bool "Detect kernel stack overflow"
 259         help
 260           This option enables the compiler option -mstack-guard and
 261           -mstack-size if they are available. If the compiler supports them
 262           it will emit additional code to each function prolog to trigger
 263           an illegal operation if the kernel stack is about to overflow.
 264
 265           Say N if you are unsure.
 266
 267 config STACK_GUARD
 268         int "Size of the guard area (128-1024)"
 269         range 128 1024
 270         depends on CHECK_STACK
 271         default "256"
 272         help
 273           This allows you to specify the size of the guard area at the lower
 274           end of the kernel stack. If the kernel stack points into the guard
 275           area on function entry an illegal operation is triggered. The size
 276           needs to be a power of 2. Please keep in mind that the size of an
 277           interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
 278           The minimum size for the stack guard should be 256 for 31 bit and
 279           512 for 64 bit.
 280
 281 config WARN_STACK
 282         bool "Emit compiler warnings for function with broken stack usage"
 283         help
 284           This option enables the compiler options -mwarn-framesize and
 285           -mwarn-dynamicstack. If the compiler supports these options it
 286           will generate warnings for function which either use alloca or
 287           create a stack frame bigger then CONFIG_WARN_STACK_SIZE.
 288
 289           Say N if you are unsure.
 290
 291 config WARN_STACK_SIZE
 292         int "Maximum frame size considered safe (128-2048)"
 293         range 128 2048
 294         depends on WARN_STACK
 295         default "2048"
 296         help
 297           This allows you to specify the maximum frame size a function may
 298           have without the compiler complaining about it.
 299
 300 config ARCH_POPULATES_NODE_MAP
 301         def_bool y
 302
 303 comment "Kernel preemption"
 304
 305 source "kernel/Kconfig.preempt"
 306
 307 config ARCH_SPARSEMEM_ENABLE
 308         def_bool y
 309         select SPARSEMEM_VMEMMAP_ENABLE
 310         select SPARSEMEM_VMEMMAP
 311         select SPARSEMEM_STATIC if !64BIT
 312
 313 config ARCH_SPARSEMEM_DEFAULT
 314         def_bool y
 315
 316 config ARCH_SELECT_MEMORY_MODEL
 317        def_bool y
 318
 319 config ARCH_ENABLE_MEMORY_HOTPLUG
 320         def_bool y
 321         depends on SPARSEMEM
 322
 323 config ARCH_ENABLE_MEMORY_HOTREMOVE
 324         def_bool y
 325
 326 source "mm/Kconfig"
 327
 328 comment "I/O subsystem configuration"
 329
 330 config MACHCHK_WARNING
 331         bool "Process warning machine checks"
 332         help
 333           Select this option if you want the machine check handler on IBM S/390 or
 334           zSeries to process warning machine checks (e.g. on power failures).
 335           If unsure, say "Y".
 336
 337 config QDIO
 338         tristate "QDIO support"
 339         ---help---
 340           This driver provides the Queued Direct I/O base support for
 341           IBM System z.
 342
 343           To compile this driver as a module, choose M here: the
 344           module will be called qdio.
 345
 346           If unsure, say Y.
 347
 348 config QDIO_DEBUG
 349         bool "Extended debugging information"
 350         depends on QDIO
 351         help
 352           Say Y here to get extended debugging output in
 353             /sys/kernel/debug/s390dbf/qdio...
 354           Warning: this option reduces the performance of the QDIO module.
 355
 356           If unsure, say N.
 357
 358 config CHSC_SCH
 359         tristate "Support for CHSC subchannels"
 360         help
 361           This driver allows usage of CHSC subchannels. A CHSC subchannel
 362           is usually present on LPAR only.
 363           The driver creates a device /dev/chsc, which may be used to
 364           obtain I/O configuration information about the machine and
 365           to issue asynchronous chsc commands (DANGEROUS).
 366           You will usually only want to use this interface on a special
 367           LPAR designated for system management.
 368
 369           To compile this driver as a module, choose M here: the
 370           module will be called chsc_sch.
 371
 372           If unsure, say N.
 373
 374 comment "Misc"
 375
 376 config IPL
 377         bool "Builtin IPL record support"
 378         help
 379           If you want to use the produced kernel to IPL directly from a
 380           device, you have to merge a bootsector specific to the device
 381           into the first bytes of the kernel. You will have to select the
 382           IPL device.
 383
 384 choice
 385         prompt "IPL method generated into head.S"
 386         depends on IPL
 387         default IPL_TAPE
 388         help
 389           Select "tape" if you want to IPL the image from a Tape.
 390
 391           Select "vm_reader" if you are running under VM/ESA and want
 392           to IPL the image from the emulated card reader.
 393
 394 config IPL_TAPE
 395         bool "tape"
 396
 397 config IPL_VM
 398         bool "vm_reader"
 399
 400 endchoice
 401
 402 source "fs/Kconfig.binfmt"
 403
 404 config FORCE_MAX_ZONEORDER
 405         int
 406         default "9"
 407
 408 config PROCESS_DEBUG
 409         bool "Show crashed user process info"
 410         help
 411           Say Y to print all process fault locations to the console.  This is
 412           a debugging option; you probably do not want to set it unless you
 413           are an S390 port maintainer.
 414
 415 config PFAULT
 416         bool "Pseudo page fault support"
 417         help
 418           Select this option, if you want to use PFAULT pseudo page fault
 419           handling under VM. If running native or in LPAR, this option
 420           has no effect. If your VM does not support PFAULT, PAGEEX
 421           pseudo page fault handling will be used.
 422           Note that VM 4.2 supports PFAULT but has a bug in its
 423           implementation that causes some problems.
 424           Everybody who wants to run Linux under VM != VM4.2 should select
 425           this option.
 426
 427 config SHARED_KERNEL
 428         bool "VM shared kernel support"
 429         help
 430           Select this option, if you want to share the text segment of the
 431           Linux kernel between different VM guests. This reduces memory
 432           usage with lots of guests but greatly increases kernel size.
 433           Also if a kernel was IPL'ed from a shared segment the kexec system
 434           call will not work.
 435           You should only select this option if you know what you are
 436           doing and want to exploit this feature.
 437
 438 config CMM
 439         tristate "Cooperative memory management"
 440         help
 441           Select this option, if you want to enable the kernel interface
 442           to reduce the memory size of the system. This is accomplished
 443           by allocating pages of memory and put them "on hold". This only
 444           makes sense for a system running under VM where the unused pages
 445           will be reused by VM for other guest systems. The interface
 446           allows an external monitor to balance memory of many systems.
 447           Everybody who wants to run Linux under VM should select this
 448           option.
 449
 450 config CMM_PROC
 451         bool "/proc interface to cooperative memory management"
 452         depends on CMM
 453         help
 454           Select this option to enable the /proc interface to the
 455           cooperative memory management.
 456
 457 config CMM_IUCV
 458         bool "IUCV special message interface to cooperative memory management"
 459         depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
 460         help
 461           Select this option to enable the special message interface to
 462           the cooperative memory management.
 463
 464 config PAGE_STATES
 465         bool "Unused page notification"
 466         help
 467           This enables the notification of unused pages to the
 468           hypervisor. The ESSA instruction is used to do the states
 469           changes between a page that has content and the unused state.
 470
 471 config VIRT_TIMER
 472         bool "Virtual CPU timer support"
 473         help
 474           This provides a kernel interface for virtual CPU timers.
 475           Default is disabled.
 476
 477 config VIRT_CPU_ACCOUNTING
 478         bool "Base user process accounting on virtual cpu timer"
 479         depends on VIRT_TIMER
 480         help
 481           Select this option to use CPU timer deltas to do user
 482           process accounting.
 483
 484 config APPLDATA_BASE
 485         bool "Linux - VM Monitor Stream, base infrastructure"
 486         depends on PROC_FS && VIRT_TIMER=y
 487         help
 488           This provides a kernel interface for creating and updating z/VM APPLDATA
 489           monitor records. The monitor records are updated at certain time
 490           intervals, once the timer is started.
 491           Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
 492           i.e. enables or disables monitoring on the Linux side.
 493           A custom interval value (in seconds) can be written to
 494           /proc/appldata/interval.
 495
 496           Defaults are 60 seconds interval and timer off.
 497           The /proc entries can also be read from, showing the current settings.
 498
 499 config APPLDATA_MEM
 500         tristate "Monitor memory management statistics"
 501         depends on APPLDATA_BASE && VM_EVENT_COUNTERS
 502         help
 503           This provides memory management related data to the Linux - VM Monitor
 504           Stream, like paging/swapping rate, memory utilisation, etc.
 505           Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
 506           APPLDATA monitor record, i.e. enables or disables monitoring this record
 507           on the z/VM side.
 508
 509           Default is disabled.
 510           The /proc entry can also be read from, showing the current settings.
 511
 512           This can also be compiled as a module, which will be called
 513           appldata_mem.o.
 514
 515 config APPLDATA_OS
 516         tristate "Monitor OS statistics"
 517         depends on APPLDATA_BASE
 518         help
 519           This provides OS related data to the Linux - VM Monitor Stream, like
 520           CPU utilisation, etc.
 521           Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
 522           APPLDATA monitor record, i.e. enables or disables monitoring this record
 523           on the z/VM side.
 524
 525           Default is disabled.
 526           This can also be compiled as a module, which will be called
 527           appldata_os.o.
 528
 529 config APPLDATA_NET_SUM
 530         tristate "Monitor overall network statistics"
 531         depends on APPLDATA_BASE
 532         help
 533           This provides network related data to the Linux - VM Monitor Stream,
 534           currently there is only a total sum of network I/O statistics, no
 535           per-interface data.
 536           Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
 537           APPLDATA monitor record, i.e. enables or disables monitoring this record
 538           on the z/VM side.
 539
 540           Default is disabled.
 541           This can also be compiled as a module, which will be called
 542           appldata_net_sum.o.
 543
 544 source kernel/Kconfig.hz
 545
 546 config S390_HYPFS_FS
 547         bool "s390 hypervisor file system support"
 548         select SYS_HYPERVISOR
 549         default y
 550         help
 551           This is a virtual file system intended to provide accounting
 552           information in an s390 hypervisor environment.
 553
 554 config KEXEC
 555         bool "kexec system call"
 556         help
 557           kexec is a system call that implements the ability to shutdown your
 558           current kernel, and to start another kernel.  It is like a reboot
 559           but is independent of hardware/microcode support.
 560
 561 config ZFCPDUMP
 562         tristate "zfcpdump support"
 563         select SMP
 564         default n
 565         help
 566           Select this option if you want to build an zfcpdump enabled kernel.
 567           Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
 568
 569 config S390_GUEST
 570 bool "s390 guest support for KVM (EXPERIMENTAL)"
 571         depends on 64BIT && EXPERIMENTAL
 572         select VIRTIO
 573         select VIRTIO_RING
 574         select VIRTIO_CONSOLE
 575         help
 576           Select this option if you want to run the kernel as a guest under
 577           the KVM hypervisor. This will add detection for KVM as well  as a
 578           virtio transport. If KVM is detected, the virtio console will be
 579           the default console.
 580 endmenu
 581
 582 source "net/Kconfig"
 583
 584 config PCMCIA
 585         def_bool n
 586
 587 config CCW
 588         def_bool y
 589
 590 source "drivers/Kconfig"
 591
 592 source "fs/Kconfig"
 593
 594 source "arch/s390/Kconfig.debug"
 595
 596 source "security/Kconfig"
 597
 598 source "crypto/Kconfig"
 599
 600 source "lib/Kconfig"
 601
 602 source "arch/s390/kvm/Kconfig"