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 RWSEM_GENERIC_SPINLOCK
  11         bool
  12
  13 config RWSEM_XCHGADD_ALGORITHM
  14         bool
  15         default y
  16
  17 config GENERIC_CALIBRATE_DELAY
  18         bool
  19         default y
  20
  21 config GENERIC_BUST_SPINLOCK
  22         bool
  23
  24 mainmenu "Linux Kernel Configuration"
  25
  26 config S390
  27         bool
  28         default y
  29
  30 source "init/Kconfig"
  31
  32 menu "Base setup"
  33
  34 comment "Processor type and features"
  35
  36 config 64BIT
  37         bool "64 bit kernel"
  38         help
  39           Select this option if you have a 64 bit IBM zSeries machine
  40           and want to use the 64 bit addressing mode.
  41
  42 config SMP
  43         bool "Symmetric multi-processing support"
  44         ---help---
  45           This enables support for systems with more than one CPU. If you have
  46           a system with only one CPU, like most personal computers, say N. If
  47           you have a system with more than one CPU, say Y.
  48
  49           If you say N here, the kernel will run on single and multiprocessor
  50           machines, but will use only one CPU of a multiprocessor machine. If
  51           you say Y here, the kernel will run on many, but not all,
  52           singleprocessor machines. On a singleprocessor machine, the kernel
  53           will run faster if you say N here.
  54
  55           See also the <file:Documentation/smp.txt> and the SMP-HOWTO
  56           available at <http://www.tldp.org/docs.html#howto>.
  57
  58           Even if you don't know what to do here, say Y.
  59
  60 config NR_CPUS
  61         int "Maximum number of CPUs (2-64)"
  62         range 2 64
  63         depends on SMP
  64         default "32"
  65         help
  66           This allows you to specify the maximum number of CPUs which this
  67           kernel will support.  The maximum supported value is 64 and the
  68           minimum value which makes sense is 2.
  69
  70           This is purely to save memory - each supported CPU adds
  71           approximately sixteen kilobytes to the kernel image.
  72
  73 config HOTPLUG_CPU
  74         bool "Support for hot-pluggable CPUs"
  75         depends on SMP
  76         select HOTPLUG
  77         default n
  78         help
  79           Say Y here to be able to turn CPUs off and on. CPUs
  80           can be controlled through /sys/devices/system/cpu/cpu#.
  81           Say N if you want to disable CPU hotplug.
  82
  83 config MATHEMU
  84         bool "IEEE FPU emulation"
  85         depends on MARCH_G5
  86         help
  87           This option is required for IEEE compliant floating point arithmetic
  88           on older S/390 machines. Say Y unless you know your machine doesn't
  89           need this.
  90
  91 config COMPAT
  92         bool "Kernel support for 31 bit emulation"
  93         depends on 64BIT
  94         help
  95           Select this option if you want to enable your system kernel to
  96           handle system-calls from ELF binaries for 31 bit ESA.  This option
  97           (and some other stuff like libraries and such) is needed for
  98           executing 31 bit applications.  It is safe to say "Y".
  99
 100 config SYSVIPC_COMPAT
 101         bool
 102         depends on COMPAT && SYSVIPC
 103         default y
 104
 105 config BINFMT_ELF32
 106         tristate "Kernel support for 31 bit ELF binaries"
 107         depends on COMPAT
 108         help
 109           This allows you to run 32-bit Linux/ELF binaries on your zSeries
 110           in 64 bit mode. Everybody wants this; say Y.
 111
 112 comment "Code generation options"
 113
 114 choice
 115         prompt "Processor type"
 116         default MARCH_G5
 117
 118 config MARCH_G5
 119         bool "S/390 model G5 and G6"
 120         depends on !64BIT
 121         help
 122           Select this to build a 31 bit kernel that works
 123           on all S/390 and zSeries machines.
 124
 125 config MARCH_Z900
 126         bool "IBM eServer zSeries model z800 and z900"
 127         help
 128           Select this to optimize for zSeries machines. This
 129           will enable some optimizations that are not available
 130           on older 31 bit only CPUs.
 131
 132 config MARCH_Z990
 133         bool "IBM eServer zSeries model z890 and z990"
 134         help
 135           Select this enable optimizations for model z890/z990.
 136           This will be slightly faster but does not work on
 137           older machines such as the z900.
 138
 139 endchoice
 140
 141 config PACK_STACK
 142         bool "Pack kernel stack"
 143         help
 144           This option enables the compiler option -mkernel-backchain if it
 145           is available. If the option is available the compiler supports
 146           the new stack layout which dramatically reduces the minimum stack
 147           frame size. With an old compiler a non-leaf function needs a
 148           minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
 149           -mkernel-backchain the minimum size drops to 16 byte on 31 bit
 150           and 24 byte on 64 bit.
 151
 152           Say Y if you are unsure.
 153
 154 config SMALL_STACK
 155         bool "Use 4kb/8kb for kernel stack instead of 8kb/16kb"
 156         depends on PACK_STACK
 157         help
 158           If you say Y here and the compiler supports the -mkernel-backchain
 159           option the kernel will use a smaller kernel stack size. For 31 bit
 160           the reduced size is 4kb instead of 8kb and for 64 bit it is 8kb
 161           instead of 16kb. This allows to run more thread on a system and
 162           reduces the pressure on the memory management for higher order
 163           page allocations.
 164
 165           Say N if you are unsure.
 166
 167
 168 config CHECK_STACK
 169         bool "Detect kernel stack overflow"
 170         help
 171           This option enables the compiler option -mstack-guard and
 172           -mstack-size if they are available. If the compiler supports them
 173           it will emit additional code to each function prolog to trigger
 174           an illegal operation if the kernel stack is about to overflow.
 175
 176           Say N if you are unsure.
 177
 178 config STACK_GUARD
 179         int "Size of the guard area (128-1024)"
 180         range 128 1024
 181         depends on CHECK_STACK
 182         default "256"
 183         help
 184           This allows you to specify the size of the guard area at the lower
 185           end of the kernel stack. If the kernel stack points into the guard
 186           area on function entry an illegal operation is triggered. The size
 187           needs to be a power of 2. Please keep in mind that the size of an
 188           interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
 189           The minimum size for the stack guard should be 256 for 31 bit and
 190           512 for 64 bit.
 191
 192 config WARN_STACK
 193         bool "Emit compiler warnings for function with broken stack usage"
 194         help
 195           This option enables the compiler options -mwarn-framesize and
 196           -mwarn-dynamicstack. If the compiler supports these options it
 197           will generate warnings for function which either use alloca or
 198           create a stack frame bigger then CONFIG_WARN_STACK_SIZE.
 199
 200           Say N if you are unsure.
 201
 202 config WARN_STACK_SIZE
 203         int "Maximum frame size considered safe (128-2048)"
 204         range 128 2048
 205         depends on WARN_STACK
 206         default "256"
 207         help
 208           This allows you to specify the maximum frame size a function may
 209           have without the compiler complaining about it.
 210
 211 source "mm/Kconfig"
 212
 213 comment "I/O subsystem configuration"
 214
 215 config MACHCHK_WARNING
 216         bool "Process warning machine checks"
 217         help
 218           Select this option if you want the machine check handler on IBM S/390 or
 219           zSeries to process warning machine checks (e.g. on power failures).
 220           If unsure, say "Y".
 221
 222 config QDIO
 223         tristate "QDIO support"
 224         ---help---
 225           This driver provides the Queued Direct I/O base support for
 226           IBM mainframes.
 227
 228           For details please refer to the documentation provided by IBM at
 229           <http://www10.software.ibm.com/developerworks/opensource/linux390>
 230
 231           To compile this driver as a module, choose M here: the
 232           module will be called qdio.
 233
 234           If unsure, say Y.
 235
 236 config QDIO_PERF_STATS
 237         bool "Performance statistics in /proc"
 238         depends on QDIO
 239         help
 240           Say Y here to get performance statistics in /proc/qdio_perf
 241
 242           If unsure, say N.
 243
 244 config QDIO_DEBUG
 245         bool "Extended debugging information"
 246         depends on QDIO
 247         help
 248           Say Y here to get extended debugging output in
 249             /sys/kernel/debug/s390dbf/qdio...
 250           Warning: this option reduces the performance of the QDIO module.
 251
 252           If unsure, say N.
 253
 254 comment "Misc"
 255
 256 config PREEMPT
 257         bool "Preemptible Kernel"
 258         help
 259           This option reduces the latency of the kernel when reacting to
 260           real-time or interactive events by allowing a low priority process to
 261           be preempted even if it is in kernel mode executing a system call.
 262           This allows applications to run more reliably even when the system is
 263           under load.
 264
 265           Say N if you are unsure.
 266
 267 config IPL
 268         bool "Builtin IPL record support"
 269         help
 270           If you want to use the produced kernel to IPL directly from a
 271           device, you have to merge a bootsector specific to the device
 272           into the first bytes of the kernel. You will have to select the
 273           IPL device.
 274
 275 choice
 276         prompt "IPL method generated into head.S"
 277         depends on IPL
 278         default IPL_TAPE
 279         help
 280           Select "tape" if you want to IPL the image from a Tape.
 281
 282           Select "vm_reader" if you are running under VM/ESA and want
 283           to IPL the image from the emulated card reader.
 284
 285 config IPL_TAPE
 286         bool "tape"
 287
 288 config IPL_VM
 289         bool "vm_reader"
 290
 291 endchoice
 292
 293 source "fs/Kconfig.binfmt"
 294
 295 config PROCESS_DEBUG
 296         bool "Show crashed user process info"
 297         help
 298           Say Y to print all process fault locations to the console.  This is
 299           a debugging option; you probably do not want to set it unless you
 300           are an S390 port maintainer.
 301
 302 config PFAULT
 303         bool "Pseudo page fault support"
 304         help
 305           Select this option, if you want to use PFAULT pseudo page fault
 306           handling under VM. If running native or in LPAR, this option
 307           has no effect. If your VM does not support PFAULT, PAGEEX
 308           pseudo page fault handling will be used.
 309           Note that VM 4.2 supports PFAULT but has a bug in its
 310           implementation that causes some problems.
 311           Everybody who wants to run Linux under VM != VM4.2 should select
 312           this option.
 313
 314 config SHARED_KERNEL
 315         bool "VM shared kernel support"
 316         help
 317           Select this option, if you want to share the text segment of the
 318           Linux kernel between different VM guests. This reduces memory
 319           usage with lots of guests but greatly increases kernel size.
 320           You should only select this option if you know what you are
 321           doing and want to exploit this feature.
 322
 323 config CMM
 324         tristate "Cooperative memory management"
 325         help
 326           Select this option, if you want to enable the kernel interface
 327           to reduce the memory size of the system. This is accomplished
 328           by allocating pages of memory and put them "on hold". This only
 329           makes sense for a system running under VM where the unused pages
 330           will be reused by VM for other guest systems. The interface
 331           allows an external monitor to balance memory of many systems.
 332           Everybody who wants to run Linux under VM should select this
 333           option.
 334
 335 config CMM_PROC
 336         bool "/proc interface to cooperative memory management"
 337         depends on CMM
 338         help
 339           Select this option to enable the /proc interface to the
 340           cooperative memory management.
 341
 342 config CMM_IUCV
 343         bool "IUCV special message interface to cooperative memory management"
 344         depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
 345         help
 346           Select this option to enable the special message interface to
 347           the cooperative memory management.
 348
 349 config VIRT_TIMER
 350         bool "Virtual CPU timer support"
 351         help
 352           This provides a kernel interface for virtual CPU timers.
 353           Default is disabled.
 354
 355 config VIRT_CPU_ACCOUNTING
 356         bool "Base user process accounting on virtual cpu timer"
 357         depends on VIRT_TIMER
 358         help
 359           Select this option to use CPU timer deltas to do user
 360           process accounting.
 361
 362 config APPLDATA_BASE
 363         bool "Linux - VM Monitor Stream, base infrastructure"
 364         depends on PROC_FS && VIRT_TIMER=y
 365         help
 366           This provides a kernel interface for creating and updating z/VM APPLDATA
 367           monitor records. The monitor records are updated at certain time
 368           intervals, once the timer is started.
 369           Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
 370           i.e. enables or disables monitoring on the Linux side.
 371           A custom interval value (in seconds) can be written to
 372           /proc/appldata/interval.
 373
 374           Defaults are 60 seconds interval and timer off.
 375           The /proc entries can also be read from, showing the current settings.
 376
 377 config APPLDATA_MEM
 378         tristate "Monitor memory management statistics"
 379         depends on APPLDATA_BASE
 380         help
 381           This provides memory management related data to the Linux - VM Monitor
 382           Stream, like paging/swapping rate, memory utilisation, etc.
 383           Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
 384           APPLDATA monitor record, i.e. enables or disables monitoring this record
 385           on the z/VM side.
 386
 387           Default is disabled.
 388           The /proc entry can also be read from, showing the current settings.
 389
 390           This can also be compiled as a module, which will be called
 391           appldata_mem.o.
 392
 393 config APPLDATA_OS
 394         tristate "Monitor OS statistics"
 395         depends on APPLDATA_BASE
 396         help
 397           This provides OS related data to the Linux - VM Monitor Stream, like
 398           CPU utilisation, etc.
 399           Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
 400           APPLDATA monitor record, i.e. enables or disables monitoring this record
 401           on the z/VM side.
 402
 403           Default is disabled.
 404           This can also be compiled as a module, which will be called
 405           appldata_os.o.
 406
 407 config APPLDATA_NET_SUM
 408         tristate "Monitor overall network statistics"
 409         depends on APPLDATA_BASE
 410         help
 411           This provides network related data to the Linux - VM Monitor Stream,
 412           currently there is only a total sum of network I/O statistics, no
 413           per-interface data.
 414           Writing 1 or 0 to /proc/appldata/net_sum 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           This can also be compiled as a module, which will be called
 420           appldata_net_sum.o.
 421
 422 config NO_IDLE_HZ
 423         bool "No HZ timer ticks in idle"
 424         help
 425           Switches the regular HZ timer off when the system is going idle.
 426           This helps z/VM to detect that the Linux system is idle. VM can
 427           then "swap-out" this guest which reduces memory usage. It also
 428           reduces the overhead of idle systems.
 429
 430           The HZ timer can be switched on/off via /proc/sys/kernel/hz_timer.
 431           hz_timer=0 means HZ timer is disabled. hz_timer=1 means HZ
 432           timer is active.
 433
 434 config NO_IDLE_HZ_INIT
 435         bool "HZ timer in idle off by default"
 436         depends on NO_IDLE_HZ
 437         help
 438           The HZ timer is switched off in idle by default. That means the
 439           HZ timer is already disabled at boot time.
 440
 441 config KEXEC
 442         bool "kexec system call (EXPERIMENTAL)"
 443         depends on EXPERIMENTAL
 444         help
 445           kexec is a system call that implements the ability to shutdown your
 446           current kernel, and to start another kernel.  It is like a reboot
 447           but is independent of hardware/microcode support.
 448
 449 endmenu
 450
 451 source "net/Kconfig"
 452
 453 config PCMCIA
 454         bool
 455         default n
 456
 457 source "drivers/base/Kconfig"
 458
 459 source "drivers/scsi/Kconfig"
 460
 461 source "drivers/s390/Kconfig"
 462
 463 source "drivers/net/Kconfig"
 464
 465 source "fs/Kconfig"
 466
 467 source "arch/s390/oprofile/Kconfig"
 468
 469 source "arch/s390/Kconfig.debug"
 470
 471 source "security/Kconfig"
 472
 473 source "crypto/Kconfig"
 474
 475 source "lib/Kconfig"