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         bool
   8         default y
   9
  10 config LOCKDEP_SUPPORT
  11         bool
  12         default y
  13
  14 config STACKTRACE_SUPPORT
  15         bool
  16         default y
  17
  18 config RWSEM_GENERIC_SPINLOCK
  19         bool
  20
  21 config RWSEM_XCHGADD_ALGORITHM
  22         bool
  23         default 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         bool
  35         default y
  36
  37 config GENERIC_CALIBRATE_DELAY
  38         bool
  39         default y
  40
  41 config GENERIC_TIME
  42         def_bool y
  43
  44 mainmenu "Linux Kernel Configuration"
  45
  46 config S390
  47         bool
  48         default y
  49
  50 source "init/Kconfig"
  51
  52 menu "Base setup"
  53
  54 comment "Processor type and features"
  55
  56 config 64BIT
  57         bool "64 bit kernel"
  58         help
  59           Select this option if you have a 64 bit IBM zSeries machine
  60           and want to use the 64 bit addressing mode.
  61
  62 config 32BIT
  63         bool
  64         default y if !64BIT
  65
  66 config SMP
  67         bool "Symmetric multi-processing support"
  68         ---help---
  69           This enables support for systems with more than one CPU. If you have
  70           a system with only one CPU, like most personal computers, say N. If
  71           you have a system with more than one CPU, say Y.
  72
  73           If you say N here, the kernel will run on single and multiprocessor
  74           machines, but will use only one CPU of a multiprocessor machine. If
  75           you say Y here, the kernel will run on many, but not all,
  76           singleprocessor machines. On a singleprocessor machine, the kernel
  77           will run faster if you say N here.
  78
  79           See also the <file:Documentation/smp.txt> and the SMP-HOWTO
  80           available at <http://www.tldp.org/docs.html#howto>.
  81
  82           Even if you don't know what to do here, say Y.
  83
  84 config NR_CPUS
  85         int "Maximum number of CPUs (2-64)"
  86         range 2 64
  87         depends on SMP
  88         default "32"
  89         help
  90           This allows you to specify the maximum number of CPUs which this
  91           kernel will support.  The maximum supported value is 64 and the
  92           minimum value which makes sense is 2.
  93
  94           This is purely to save memory - each supported CPU adds
  95           approximately sixteen kilobytes to the kernel image.
  96
  97 config HOTPLUG_CPU
  98         bool "Support for hot-pluggable CPUs"
  99         depends on SMP
 100         select HOTPLUG
 101         default n
 102         help
 103           Say Y here to be able to turn CPUs off and on. CPUs
 104           can be controlled through /sys/devices/system/cpu/cpu#.
 105           Say N if you want to disable CPU hotplug.
 106
 107 config DEFAULT_MIGRATION_COST
 108         int
 109         default "1000000"
 110
 111 config MATHEMU
 112         bool "IEEE FPU emulation"
 113         depends on MARCH_G5
 114         help
 115           This option is required for IEEE compliant floating point arithmetic
 116           on older S/390 machines. Say Y unless you know your machine doesn't
 117           need this.
 118
 119 config COMPAT
 120         bool "Kernel support for 31 bit emulation"
 121         depends on 64BIT
 122         help
 123           Select this option if you want to enable your system kernel to
 124           handle system-calls from ELF binaries for 31 bit ESA.  This option
 125           (and some other stuff like libraries and such) is needed for
 126           executing 31 bit applications.  It is safe to say "Y".
 127
 128 config SYSVIPC_COMPAT
 129         bool
 130         depends on COMPAT && SYSVIPC
 131         default y
 132
 133 config AUDIT_ARCH
 134         bool
 135         default y
 136
 137 comment "Code generation options"
 138
 139 choice
 140         prompt "Processor type"
 141         default MARCH_G5
 142
 143 config MARCH_G5
 144         bool "S/390 model G5 and G6"
 145         depends on !64BIT
 146         help
 147           Select this to build a 31 bit kernel that works
 148           on all S/390 and zSeries machines.
 149
 150 config MARCH_Z900
 151         bool "IBM eServer zSeries model z800 and z900"
 152         help
 153           Select this to optimize for zSeries machines. This
 154           will enable some optimizations that are not available
 155           on older 31 bit only CPUs.
 156
 157 config MARCH_Z990
 158         bool "IBM eServer zSeries model z890 and z990"
 159         help
 160           Select this enable optimizations for model z890/z990.
 161           This will be slightly faster but does not work on
 162           older machines such as the z900.
 163
 164 config MARCH_Z9_109
 165         bool "IBM System z9"
 166         help
 167           Select this to enable optimizations for IBM System z9-109, IBM
 168           System z9 Enterprise Class (z9 EC), and IBM System z9 Business
 169           Class (z9 BC). The kernel will be slightly faster but will not
 170           work on older machines such as the z990, z890, z900, and z800.
 171
 172 endchoice
 173
 174 config PACK_STACK
 175         bool "Pack kernel stack"
 176         help
 177           This option enables the compiler option -mkernel-backchain if it
 178           is available. If the option is available the compiler supports
 179           the new stack layout which dramatically reduces the minimum stack
 180           frame size. With an old compiler a non-leaf function needs a
 181           minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
 182           -mkernel-backchain the minimum size drops to 16 byte on 31 bit
 183           and 24 byte on 64 bit.
 184
 185           Say Y if you are unsure.
 186
 187 config SMALL_STACK
 188         bool "Use 4kb/8kb for kernel stack instead of 8kb/16kb"
 189         depends on PACK_STACK && !LOCKDEP
 190         help
 191           If you say Y here and the compiler supports the -mkernel-backchain
 192           option the kernel will use a smaller kernel stack size. For 31 bit
 193           the reduced size is 4kb instead of 8kb and for 64 bit it is 8kb
 194           instead of 16kb. This allows to run more thread on a system and
 195           reduces the pressure on the memory management for higher order
 196           page allocations.
 197
 198           Say N if you are unsure.
 199
 200
 201 config CHECK_STACK
 202         bool "Detect kernel stack overflow"
 203         help
 204           This option enables the compiler option -mstack-guard and
 205           -mstack-size if they are available. If the compiler supports them
 206           it will emit additional code to each function prolog to trigger
 207           an illegal operation if the kernel stack is about to overflow.
 208
 209           Say N if you are unsure.
 210
 211 config STACK_GUARD
 212         int "Size of the guard area (128-1024)"
 213         range 128 1024
 214         depends on CHECK_STACK
 215         default "256"
 216         help
 217           This allows you to specify the size of the guard area at the lower
 218           end of the kernel stack. If the kernel stack points into the guard
 219           area on function entry an illegal operation is triggered. The size
 220           needs to be a power of 2. Please keep in mind that the size of an
 221           interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
 222           The minimum size for the stack guard should be 256 for 31 bit and
 223           512 for 64 bit.
 224
 225 config WARN_STACK
 226         bool "Emit compiler warnings for function with broken stack usage"
 227         help
 228           This option enables the compiler options -mwarn-framesize and
 229           -mwarn-dynamicstack. If the compiler supports these options it
 230           will generate warnings for function which either use alloca or
 231           create a stack frame bigger then CONFIG_WARN_STACK_SIZE.
 232
 233           Say N if you are unsure.
 234
 235 config WARN_STACK_SIZE
 236         int "Maximum frame size considered safe (128-2048)"
 237         range 128 2048
 238         depends on WARN_STACK
 239         default "256"
 240         help
 241           This allows you to specify the maximum frame size a function may
 242           have without the compiler complaining about it.
 243
 244 config ARCH_POPULATES_NODE_MAP
 245         def_bool y
 246
 247 source "mm/Kconfig"
 248
 249 config HOLES_IN_ZONE
 250         def_bool y
 251
 252 comment "I/O subsystem configuration"
 253
 254 config MACHCHK_WARNING
 255         bool "Process warning machine checks"
 256         help
 257           Select this option if you want the machine check handler on IBM S/390 or
 258           zSeries to process warning machine checks (e.g. on power failures).
 259           If unsure, say "Y".
 260
 261 config QDIO
 262         tristate "QDIO support"
 263         ---help---
 264           This driver provides the Queued Direct I/O base support for
 265           IBM mainframes.
 266
 267           For details please refer to the documentation provided by IBM at
 268           <http://www10.software.ibm.com/developerworks/opensource/linux390>
 269
 270           To compile this driver as a module, choose M here: the
 271           module will be called qdio.
 272
 273           If unsure, say Y.
 274
 275 config QDIO_DEBUG
 276         bool "Extended debugging information"
 277         depends on QDIO
 278         help
 279           Say Y here to get extended debugging output in
 280             /sys/kernel/debug/s390dbf/qdio...
 281           Warning: this option reduces the performance of the QDIO module.
 282
 283           If unsure, say N.
 284
 285 comment "Misc"
 286
 287 config PREEMPT
 288         bool "Preemptible Kernel"
 289         help
 290           This option reduces the latency of the kernel when reacting to
 291           real-time or interactive events by allowing a low priority process to
 292           be preempted even if it is in kernel mode executing a system call.
 293           This allows applications to run more reliably even when the system is
 294           under load.
 295
 296           Say N if you are unsure.
 297
 298 config IPL
 299         bool "Builtin IPL record support"
 300         help
 301           If you want to use the produced kernel to IPL directly from a
 302           device, you have to merge a bootsector specific to the device
 303           into the first bytes of the kernel. You will have to select the
 304           IPL device.
 305
 306 choice
 307         prompt "IPL method generated into head.S"
 308         depends on IPL
 309         default IPL_TAPE
 310         help
 311           Select "tape" if you want to IPL the image from a Tape.
 312
 313           Select "vm_reader" if you are running under VM/ESA and want
 314           to IPL the image from the emulated card reader.
 315
 316 config IPL_TAPE
 317         bool "tape"
 318
 319 config IPL_VM
 320         bool "vm_reader"
 321
 322 endchoice
 323
 324 source "fs/Kconfig.binfmt"
 325
 326 config PROCESS_DEBUG
 327         bool "Show crashed user process info"
 328         help
 329           Say Y to print all process fault locations to the console.  This is
 330           a debugging option; you probably do not want to set it unless you
 331           are an S390 port maintainer.
 332
 333 config PFAULT
 334         bool "Pseudo page fault support"
 335         help
 336           Select this option, if you want to use PFAULT pseudo page fault
 337           handling under VM. If running native or in LPAR, this option
 338           has no effect. If your VM does not support PFAULT, PAGEEX
 339           pseudo page fault handling will be used.
 340           Note that VM 4.2 supports PFAULT but has a bug in its
 341           implementation that causes some problems.
 342           Everybody who wants to run Linux under VM != VM4.2 should select
 343           this option.
 344
 345 config SHARED_KERNEL
 346         bool "VM shared kernel support"
 347         help
 348           Select this option, if you want to share the text segment of the
 349           Linux kernel between different VM guests. This reduces memory
 350           usage with lots of guests but greatly increases kernel size.
 351           You should only select this option if you know what you are
 352           doing and want to exploit this feature.
 353
 354 config CMM
 355         tristate "Cooperative memory management"
 356         help
 357           Select this option, if you want to enable the kernel interface
 358           to reduce the memory size of the system. This is accomplished
 359           by allocating pages of memory and put them "on hold". This only
 360           makes sense for a system running under VM where the unused pages
 361           will be reused by VM for other guest systems. The interface
 362           allows an external monitor to balance memory of many systems.
 363           Everybody who wants to run Linux under VM should select this
 364           option.
 365
 366 config CMM_PROC
 367         bool "/proc interface to cooperative memory management"
 368         depends on CMM
 369         help
 370           Select this option to enable the /proc interface to the
 371           cooperative memory management.
 372
 373 config CMM_IUCV
 374         bool "IUCV special message interface to cooperative memory management"
 375         depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
 376         help
 377           Select this option to enable the special message interface to
 378           the cooperative memory management.
 379
 380 config VIRT_TIMER
 381         bool "Virtual CPU timer support"
 382         help
 383           This provides a kernel interface for virtual CPU timers.
 384           Default is disabled.
 385
 386 config VIRT_CPU_ACCOUNTING
 387         bool "Base user process accounting on virtual cpu timer"
 388         depends on VIRT_TIMER
 389         help
 390           Select this option to use CPU timer deltas to do user
 391           process accounting.
 392
 393 config APPLDATA_BASE
 394         bool "Linux - VM Monitor Stream, base infrastructure"
 395         depends on PROC_FS && VIRT_TIMER=y
 396         help
 397           This provides a kernel interface for creating and updating z/VM APPLDATA
 398           monitor records. The monitor records are updated at certain time
 399           intervals, once the timer is started.
 400           Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
 401           i.e. enables or disables monitoring on the Linux side.
 402           A custom interval value (in seconds) can be written to
 403           /proc/appldata/interval.
 404
 405           Defaults are 60 seconds interval and timer off.
 406           The /proc entries can also be read from, showing the current settings.
 407
 408 config APPLDATA_MEM
 409         tristate "Monitor memory management statistics"
 410         depends on APPLDATA_BASE
 411         help
 412           This provides memory management related data to the Linux - VM Monitor
 413           Stream, like paging/swapping rate, memory utilisation, etc.
 414           Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
 415           APPLDATA monitor record, i.e. enables or disables monitoring this record
 416           on the z/VM side.
 417
 418           Default is disabled.
 419           The /proc entry can also be read from, showing the current settings.
 420
 421           This can also be compiled as a module, which will be called
 422           appldata_mem.o.
 423
 424 config APPLDATA_OS
 425         tristate "Monitor OS statistics"
 426         depends on APPLDATA_BASE
 427         help
 428           This provides OS related data to the Linux - VM Monitor Stream, like
 429           CPU utilisation, etc.
 430           Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
 431           APPLDATA monitor record, i.e. enables or disables monitoring this record
 432           on the z/VM side.
 433
 434           Default is disabled.
 435           This can also be compiled as a module, which will be called
 436           appldata_os.o.
 437
 438 config APPLDATA_NET_SUM
 439         tristate "Monitor overall network statistics"
 440         depends on APPLDATA_BASE
 441         help
 442           This provides network related data to the Linux - VM Monitor Stream,
 443           currently there is only a total sum of network I/O statistics, no
 444           per-interface data.
 445           Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
 446           APPLDATA monitor record, i.e. enables or disables monitoring this record
 447           on the z/VM side.
 448
 449           Default is disabled.
 450           This can also be compiled as a module, which will be called
 451           appldata_net_sum.o.
 452
 453 config NO_IDLE_HZ
 454         bool "No HZ timer ticks in idle"
 455         help
 456           Switches the regular HZ timer off when the system is going idle.
 457           This helps z/VM to detect that the Linux system is idle. VM can
 458           then "swap-out" this guest which reduces memory usage. It also
 459           reduces the overhead of idle systems.
 460
 461           The HZ timer can be switched on/off via /proc/sys/kernel/hz_timer.
 462           hz_timer=0 means HZ timer is disabled. hz_timer=1 means HZ
 463           timer is active.
 464
 465 config NO_IDLE_HZ_INIT
 466         bool "HZ timer in idle off by default"
 467         depends on NO_IDLE_HZ
 468         help
 469           The HZ timer is switched off in idle by default. That means the
 470           HZ timer is already disabled at boot time.
 471
 472 config S390_HYPFS_FS
 473         bool "s390 hypervisor file system support"
 474         select SYS_HYPERVISOR
 475         default y
 476         help
 477           This is a virtual file system intended to provide accounting
 478           information in an s390 hypervisor environment.
 479
 480 config KEXEC
 481         bool "kexec system call"
 482         help
 483           kexec is a system call that implements the ability to shutdown your
 484           current kernel, and to start another kernel.  It is like a reboot
 485           but is independent of hardware/microcode support.
 486
 487 endmenu
 488
 489 source "net/Kconfig"
 490
 491 config PCMCIA
 492         bool
 493         default n
 494
 495 source "drivers/base/Kconfig"
 496
 497 source "drivers/connector/Kconfig"
 498
 499 source "drivers/scsi/Kconfig"
 500
 501 source "drivers/s390/Kconfig"
 502
 503 source "drivers/net/Kconfig"
 504
 505 source "fs/Kconfig"
 506
 507 menu "Instrumentation Support"
 508
 509 source "arch/s390/oprofile/Kconfig"
 510
 511 config KPROBES
 512         bool "Kprobes (EXPERIMENTAL)"
 513         depends on EXPERIMENTAL && MODULES
 514         help
 515           Kprobes allows you to trap at almost any kernel address and
 516           execute a callback function.  register_kprobe() establishes
 517           a probepoint and specifies the callback.  Kprobes is useful
 518           for kernel debugging, non-intrusive instrumentation and testing.
 519           If in doubt, say "N".
 520
 521 endmenu
 522
 523 source "arch/s390/Kconfig.debug"
 524
 525 source "security/Kconfig"
 526
 527 source "crypto/Kconfig"
 528
 529 source "lib/Kconfig"