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 MMU
   7         def_bool y
   8
   9 config ZONE_DMA
  10         def_bool y
  11         depends on 64BIT
  12
  13 config LOCKDEP_SUPPORT
  14         def_bool y
  15
  16 config STACKTRACE_SUPPORT
  17         def_bool y
  18
  19 config RWSEM_GENERIC_SPINLOCK
  20         bool
  21
  22 config RWSEM_XCHGADD_ALGORITHM
  23         def_bool y
  24
  25 config ARCH_HAS_ILOG2_U32
  26         bool
  27         default n
  28
  29 config ARCH_HAS_ILOG2_U64
  30         bool
  31         default n
  32
  33 config GENERIC_HWEIGHT
  34         def_bool y
  35
  36 config GENERIC_TIME
  37         def_bool y
  38
  39 config GENERIC_BUG
  40         bool
  41         depends on BUG
  42         default y
  43
  44 config NO_IOMEM
  45         def_bool y
  46
  47 config NO_DMA
  48         def_bool y
  49
  50 mainmenu "Linux Kernel Configuration"
  51
  52 config S390
  53         def_bool y
  54
  55 source "init/Kconfig"
  56
  57 menu "Base setup"
  58
  59 comment "Processor type and features"
  60
  61 config 64BIT
  62         bool "64 bit kernel"
  63         help
  64           Select this option if you have a 64 bit IBM zSeries machine
  65           and want to use the 64 bit addressing mode.
  66
  67 config 32BIT
  68         bool
  69         default y if !64BIT
  70
  71 config SMP
  72         bool "Symmetric multi-processing support"
  73         ---help---
  74           This enables support for systems with more than one CPU. If you have
  75           a system with only one CPU, like most personal computers, say N. If
  76           you have a system with more than one CPU, say Y.
  77
  78           If you say N here, the kernel will run on single and multiprocessor
  79           machines, but will use only one CPU of a multiprocessor machine. If
  80           you say Y here, the kernel will run on many, but not all,
  81           singleprocessor machines. On a singleprocessor machine, the kernel
  82           will run faster if you say N here.
  83
  84           See also the SMP-HOWTO available at
  85           <http://www.tldp.org/docs.html#howto>.
  86
  87           Even if you don't know what to do here, say Y.
  88
  89 config NR_CPUS
  90         int "Maximum number of CPUs (2-64)"
  91         range 2 64
  92         depends on SMP
  93         default "32"
  94         help
  95           This allows you to specify the maximum number of CPUs which this
  96           kernel will support.  The maximum supported value is 64 and the
  97           minimum value which makes sense is 2.
  98
  99           This is purely to save memory - each supported CPU adds
 100           approximately sixteen kilobytes to the kernel image.
 101
 102 config HOTPLUG_CPU
 103         bool "Support for hot-pluggable CPUs"
 104         depends on SMP
 105         select HOTPLUG
 106         default n
 107         help
 108           Say Y here to be able to turn CPUs off and on. CPUs
 109           can be controlled through /sys/devices/system/cpu/cpu#.
 110           Say N if you want to disable CPU hotplug.
 111
 112 config MATHEMU
 113         bool "IEEE FPU emulation"
 114         depends on MARCH_G5
 115         help
 116           This option is required for IEEE compliant floating point arithmetic
 117           on older S/390 machines. Say Y unless you know your machine doesn't
 118           need this.
 119
 120 config COMPAT
 121         bool "Kernel support for 31 bit emulation"
 122         depends on 64BIT
 123         help
 124           Select this option if you want to enable your system kernel to
 125           handle system-calls from ELF binaries for 31 bit ESA.  This option
 126           (and some other stuff like libraries and such) is needed for
 127           executing 31 bit applications.  It is safe to say "Y".
 128
 129 config SYSVIPC_COMPAT
 130         bool
 131         depends on COMPAT && SYSVIPC
 132         default y
 133
 134 config AUDIT_ARCH
 135         bool
 136         default y
 137
 138 config S390_SWITCH_AMODE
 139         bool "Switch kernel/user addressing modes"
 140         help
 141           This option allows to switch the addressing modes of kernel and user
 142           space. The kernel parameter switch_amode=on will enable this feature,
 143           default is disabled. Enabling this (via kernel parameter) on machines
 144           earlier than IBM System z9-109 EC/BC will reduce system performance.
 145
 146           Note that this option will also be selected by selecting the execute
 147           protection option below. Enabling the execute protection via the
 148           noexec kernel parameter will also switch the addressing modes,
 149           independent of the switch_amode kernel parameter.
 150
 151
 152 config S390_EXEC_PROTECT
 153         bool "Data execute protection"
 154         select S390_SWITCH_AMODE
 155         help
 156           This option allows to enable a buffer overflow protection for user
 157           space programs and it also selects the addressing mode option above.
 158           The kernel parameter noexec=on will enable this feature and also
 159           switch the addressing modes, default is disabled. Enabling this (via
 160           kernel parameter) on machines earlier than IBM System z9-109 EC/BC
 161           will reduce system performance.
 162
 163 comment "Code generation options"
 164
 165 choice
 166         prompt "Processor type"
 167         default MARCH_G5
 168
 169 config MARCH_G5
 170         bool "S/390 model G5 and G6"
 171         depends on !64BIT
 172         help
 173           Select this to build a 31 bit kernel that works
 174           on all S/390 and zSeries machines.
 175
 176 config MARCH_Z900
 177         bool "IBM eServer zSeries model z800 and z900"
 178         help
 179           Select this to optimize for zSeries machines. This
 180           will enable some optimizations that are not available
 181           on older 31 bit only CPUs.
 182
 183 config MARCH_Z990
 184         bool "IBM eServer zSeries model z890 and z990"
 185         help
 186           Select this enable optimizations for model z890/z990.
 187           This will be slightly faster but does not work on
 188           older machines such as the z900.
 189
 190 config MARCH_Z9_109
 191         bool "IBM System z9"
 192         help
 193           Select this to enable optimizations for IBM System z9-109, IBM
 194           System z9 Enterprise Class (z9 EC), and IBM System z9 Business
 195           Class (z9 BC). The kernel will be slightly faster but will not
 196           work on older machines such as the z990, z890, z900, and z800.
 197
 198 endchoice
 199
 200 config PACK_STACK
 201         bool "Pack kernel stack"
 202         help
 203           This option enables the compiler option -mkernel-backchain if it
 204           is available. If the option is available the compiler supports
 205           the new stack layout which dramatically reduces the minimum stack
 206           frame size. With an old compiler a non-leaf function needs a
 207           minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
 208           -mkernel-backchain the minimum size drops to 16 byte on 31 bit
 209           and 24 byte on 64 bit.
 210
 211           Say Y if you are unsure.
 212
 213 config SMALL_STACK
 214         bool "Use 4kb/8kb for kernel stack instead of 8kb/16kb"
 215         depends on PACK_STACK && !LOCKDEP
 216         help
 217           If you say Y here and the compiler supports the -mkernel-backchain
 218           option the kernel will use a smaller kernel stack size. For 31 bit
 219           the reduced size is 4kb instead of 8kb and for 64 bit it is 8kb
 220           instead of 16kb. This allows to run more thread on a system and
 221           reduces the pressure on the memory management for higher order
 222           page allocations.
 223
 224           Say N if you are unsure.
 225
 226
 227 config CHECK_STACK
 228         bool "Detect kernel stack overflow"
 229         help
 230           This option enables the compiler option -mstack-guard and
 231           -mstack-size if they are available. If the compiler supports them
 232           it will emit additional code to each function prolog to trigger
 233           an illegal operation if the kernel stack is about to overflow.
 234
 235           Say N if you are unsure.
 236
 237 config STACK_GUARD
 238         int "Size of the guard area (128-1024)"
 239         range 128 1024
 240         depends on CHECK_STACK
 241         default "256"
 242         help
 243           This allows you to specify the size of the guard area at the lower
 244           end of the kernel stack. If the kernel stack points into the guard
 245           area on function entry an illegal operation is triggered. The size
 246           needs to be a power of 2. Please keep in mind that the size of an
 247           interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
 248           The minimum size for the stack guard should be 256 for 31 bit and
 249           512 for 64 bit.
 250
 251 config WARN_STACK
 252         bool "Emit compiler warnings for function with broken stack usage"
 253         help
 254           This option enables the compiler options -mwarn-framesize and
 255           -mwarn-dynamicstack. If the compiler supports these options it
 256           will generate warnings for function which either use alloca or
 257           create a stack frame bigger then CONFIG_WARN_STACK_SIZE.
 258
 259           Say N if you are unsure.
 260
 261 config WARN_STACK_SIZE
 262         int "Maximum frame size considered safe (128-2048)"
 263         range 128 2048
 264         depends on WARN_STACK
 265         default "256"
 266         help
 267           This allows you to specify the maximum frame size a function may
 268           have without the compiler complaining about it.
 269
 270 config ARCH_POPULATES_NODE_MAP
 271         def_bool y
 272
 273 comment "Kernel preemption"
 274
 275 source "kernel/Kconfig.preempt"
 276
 277 source "mm/Kconfig"
 278
 279 comment "I/O subsystem configuration"
 280
 281 config MACHCHK_WARNING
 282         bool "Process warning machine checks"
 283         help
 284           Select this option if you want the machine check handler on IBM S/390 or
 285           zSeries to process warning machine checks (e.g. on power failures).
 286           If unsure, say "Y".
 287
 288 config QDIO
 289         tristate "QDIO support"
 290         ---help---
 291           This driver provides the Queued Direct I/O base support for
 292           IBM mainframes.
 293
 294           For details please refer to the documentation provided by IBM at
 295           <http://www10.software.ibm.com/developerworks/opensource/linux390>
 296
 297           To compile this driver as a module, choose M here: the
 298           module will be called qdio.
 299
 300           If unsure, say Y.
 301
 302 config QDIO_DEBUG
 303         bool "Extended debugging information"
 304         depends on QDIO
 305         help
 306           Say Y here to get extended debugging output in
 307             /sys/kernel/debug/s390dbf/qdio...
 308           Warning: this option reduces the performance of the QDIO module.
 309
 310           If unsure, say N.
 311
 312 comment "Misc"
 313
 314 config IPL
 315         bool "Builtin IPL record support"
 316         help
 317           If you want to use the produced kernel to IPL directly from a
 318           device, you have to merge a bootsector specific to the device
 319           into the first bytes of the kernel. You will have to select the
 320           IPL device.
 321
 322 choice
 323         prompt "IPL method generated into head.S"
 324         depends on IPL
 325         default IPL_TAPE
 326         help
 327           Select "tape" if you want to IPL the image from a Tape.
 328
 329           Select "vm_reader" if you are running under VM/ESA and want
 330           to IPL the image from the emulated card reader.
 331
 332 config IPL_TAPE
 333         bool "tape"
 334
 335 config IPL_VM
 336         bool "vm_reader"
 337
 338 endchoice
 339
 340 source "fs/Kconfig.binfmt"
 341
 342 config PROCESS_DEBUG
 343         bool "Show crashed user process info"
 344         help
 345           Say Y to print all process fault locations to the console.  This is
 346           a debugging option; you probably do not want to set it unless you
 347           are an S390 port maintainer.
 348
 349 config PFAULT
 350         bool "Pseudo page fault support"
 351         help
 352           Select this option, if you want to use PFAULT pseudo page fault
 353           handling under VM. If running native or in LPAR, this option
 354           has no effect. If your VM does not support PFAULT, PAGEEX
 355           pseudo page fault handling will be used.
 356           Note that VM 4.2 supports PFAULT but has a bug in its
 357           implementation that causes some problems.
 358           Everybody who wants to run Linux under VM != VM4.2 should select
 359           this option.
 360
 361 config SHARED_KERNEL
 362         bool "VM shared kernel support"
 363         help
 364           Select this option, if you want to share the text segment of the
 365           Linux kernel between different VM guests. This reduces memory
 366           usage with lots of guests but greatly increases kernel size.
 367           Also if a kernel was IPL'ed from a shared segment the kexec system
 368           call will not work.
 369           You should only select this option if you know what you are
 370           doing and want to exploit this feature.
 371
 372 config CMM
 373         tristate "Cooperative memory management"
 374         help
 375           Select this option, if you want to enable the kernel interface
 376           to reduce the memory size of the system. This is accomplished
 377           by allocating pages of memory and put them "on hold". This only
 378           makes sense for a system running under VM where the unused pages
 379           will be reused by VM for other guest systems. The interface
 380           allows an external monitor to balance memory of many systems.
 381           Everybody who wants to run Linux under VM should select this
 382           option.
 383
 384 config CMM_PROC
 385         bool "/proc interface to cooperative memory management"
 386         depends on CMM
 387         help
 388           Select this option to enable the /proc interface to the
 389           cooperative memory management.
 390
 391 config CMM_IUCV
 392         bool "IUCV special message interface to cooperative memory management"
 393         depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
 394         help
 395           Select this option to enable the special message interface to
 396           the cooperative memory management.
 397
 398 config VIRT_TIMER
 399         bool "Virtual CPU timer support"
 400         help
 401           This provides a kernel interface for virtual CPU timers.
 402           Default is disabled.
 403
 404 config VIRT_CPU_ACCOUNTING
 405         bool "Base user process accounting on virtual cpu timer"
 406         depends on VIRT_TIMER
 407         help
 408           Select this option to use CPU timer deltas to do user
 409           process accounting.
 410
 411 config APPLDATA_BASE
 412         bool "Linux - VM Monitor Stream, base infrastructure"
 413         depends on PROC_FS && VIRT_TIMER=y
 414         help
 415           This provides a kernel interface for creating and updating z/VM APPLDATA
 416           monitor records. The monitor records are updated at certain time
 417           intervals, once the timer is started.
 418           Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
 419           i.e. enables or disables monitoring on the Linux side.
 420           A custom interval value (in seconds) can be written to
 421           /proc/appldata/interval.
 422
 423           Defaults are 60 seconds interval and timer off.
 424           The /proc entries can also be read from, showing the current settings.
 425
 426 config APPLDATA_MEM
 427         tristate "Monitor memory management statistics"
 428         depends on APPLDATA_BASE && VM_EVENT_COUNTERS
 429         help
 430           This provides memory management related data to the Linux - VM Monitor
 431           Stream, like paging/swapping rate, memory utilisation, etc.
 432           Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
 433           APPLDATA monitor record, i.e. enables or disables monitoring this record
 434           on the z/VM side.
 435
 436           Default is disabled.
 437           The /proc entry can also be read from, showing the current settings.
 438
 439           This can also be compiled as a module, which will be called
 440           appldata_mem.o.
 441
 442 config APPLDATA_OS
 443         tristate "Monitor OS statistics"
 444         depends on APPLDATA_BASE
 445         help
 446           This provides OS related data to the Linux - VM Monitor Stream, like
 447           CPU utilisation, etc.
 448           Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
 449           APPLDATA monitor record, i.e. enables or disables monitoring this record
 450           on the z/VM side.
 451
 452           Default is disabled.
 453           This can also be compiled as a module, which will be called
 454           appldata_os.o.
 455
 456 config APPLDATA_NET_SUM
 457         tristate "Monitor overall network statistics"
 458         depends on APPLDATA_BASE
 459         help
 460           This provides network related data to the Linux - VM Monitor Stream,
 461           currently there is only a total sum of network I/O statistics, no
 462           per-interface data.
 463           Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
 464           APPLDATA monitor record, i.e. enables or disables monitoring this record
 465           on the z/VM side.
 466
 467           Default is disabled.
 468           This can also be compiled as a module, which will be called
 469           appldata_net_sum.o.
 470
 471 source kernel/Kconfig.hz
 472
 473 config NO_IDLE_HZ
 474         bool "No HZ timer ticks in idle"
 475         help
 476           Switches the regular HZ timer off when the system is going idle.
 477           This helps z/VM to detect that the Linux system is idle. VM can
 478           then "swap-out" this guest which reduces memory usage. It also
 479           reduces the overhead of idle systems.
 480
 481           The HZ timer can be switched on/off via /proc/sys/kernel/hz_timer.
 482           hz_timer=0 means HZ timer is disabled. hz_timer=1 means HZ
 483           timer is active.
 484
 485 config NO_IDLE_HZ_INIT
 486         bool "HZ timer in idle off by default"
 487         depends on NO_IDLE_HZ
 488         help
 489           The HZ timer is switched off in idle by default. That means the
 490           HZ timer is already disabled at boot time.
 491
 492 config S390_HYPFS_FS
 493         bool "s390 hypervisor file system support"
 494         select SYS_HYPERVISOR
 495         default y
 496         help
 497           This is a virtual file system intended to provide accounting
 498           information in an s390 hypervisor environment.
 499
 500 config KEXEC
 501         bool "kexec system call"
 502         help
 503           kexec is a system call that implements the ability to shutdown your
 504           current kernel, and to start another kernel.  It is like a reboot
 505           but is independent of hardware/microcode support.
 506
 507 config ZFCPDUMP
 508         tristate "zfcpdump support"
 509         select SMP
 510         default n
 511         help
 512           Select this option if you want to build an zfcpdump enabled kernel.
 513           Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
 514
 515 endmenu
 516
 517 source "net/Kconfig"
 518
 519 config PCMCIA
 520         def_bool n
 521
 522 config CCW
 523         def_bool y
 524
 525 source "drivers/Kconfig"
 526
 527 source "fs/Kconfig"
 528
 529 source "kernel/Kconfig.instrumentation"
 530
 531 source "arch/s390/Kconfig.debug"
 532
 533 source "security/Kconfig"
 534
 535 source "crypto/Kconfig"
 536
 537 source "lib/Kconfig"