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 ARCH_S390
  27         bool
  28         default y
  29
  30 config UID16
  31         bool
  32         default y
  33         depends on ARCH_S390X = 'n'
  34
  35 source "init/Kconfig"
  36
  37 menu "Base setup"
  38
  39 comment "Processor type and features"
  40
  41 config ARCH_S390X
  42         bool "64 bit kernel"
  43         help
  44           Select this option if you have a 64 bit IBM zSeries machine
  45           and want to use the 64 bit addressing mode.
  46
  47 config 64BIT
  48         def_bool ARCH_S390X
  49
  50 config ARCH_S390_31
  51         bool
  52         depends on ARCH_S390X = 'n'
  53         default y
  54
  55 config SMP
  56         bool "Symmetric multi-processing support"
  57         ---help---
  58           This enables support for systems with more than one CPU. If you have
  59           a system with only one CPU, like most personal computers, say N. If
  60           you have a system with more than one CPU, say Y.
  61
  62           If you say N here, the kernel will run on single and multiprocessor
  63           machines, but will use only one CPU of a multiprocessor machine. If
  64           you say Y here, the kernel will run on many, but not all,
  65           singleprocessor machines. On a singleprocessor machine, the kernel
  66           will run faster if you say N here.
  67
  68           See also the <file:Documentation/smp.txt> and the SMP-HOWTO
  69           available at <http://www.tldp.org/docs.html#howto>.
  70
  71           Even if you don't know what to do here, say Y.
  72
  73 config NR_CPUS
  74         int "Maximum number of CPUs (2-64)"
  75         range 2 64
  76         depends on SMP
  77         default "32"
  78         help
  79           This allows you to specify the maximum number of CPUs which this
  80           kernel will support.  The maximum supported value is 64 and the
  81           minimum value which makes sense is 2.
  82
  83           This is purely to save memory - each supported CPU adds
  84           approximately sixteen kilobytes to the kernel image.
  85
  86 config HOTPLUG_CPU
  87         bool "Support for hot-pluggable CPUs"
  88         depends on SMP
  89         select HOTPLUG
  90         default n
  91         help
  92           Say Y here to be able to turn CPUs off and on. CPUs
  93           can be controlled through /sys/devices/system/cpu/cpu#.
  94           Say N if you want to disable CPU hotplug.
  95
  96 config MATHEMU
  97         bool "IEEE FPU emulation"
  98         depends on MARCH_G5
  99         help
 100           This option is required for IEEE compliant floating point arithmetic
 101           on older S/390 machines. Say Y unless you know your machine doesn't
 102           need this.
 103
 104 config S390_SUPPORT
 105         bool "Kernel support for 31 bit emulation"
 106         depends on ARCH_S390X
 107         help
 108           Select this option if you want to enable your system kernel to
 109           handle system-calls from ELF binaries for 31 bit ESA.  This option
 110           (and some other stuff like libraries and such) is needed for
 111           executing 31 bit applications.  It is safe to say "Y".
 112
 113 config COMPAT
 114         bool
 115         depends on S390_SUPPORT
 116         default y
 117
 118 config SYSVIPC_COMPAT
 119         bool
 120         depends on COMPAT && SYSVIPC
 121         default y
 122
 123 config BINFMT_ELF32
 124         tristate "Kernel support for 31 bit ELF binaries"
 125         depends on S390_SUPPORT
 126         help
 127           This allows you to run 32-bit Linux/ELF binaries on your zSeries
 128           in 64 bit mode. Everybody wants this; say Y.
 129
 130 comment "Code generation options"
 131
 132 choice
 133         prompt "Processor type"
 134         default MARCH_G5
 135
 136 config MARCH_G5
 137         bool "S/390 model G5 and G6"
 138         depends on ARCH_S390_31
 139         help
 140           Select this to build a 31 bit kernel that works
 141           on all S/390 and zSeries machines.
 142
 143 config MARCH_Z900
 144         bool "IBM eServer zSeries model z800 and z900"
 145         help
 146           Select this to optimize for zSeries machines. This
 147           will enable some optimizations that are not available
 148           on older 31 bit only CPUs.
 149
 150 config MARCH_Z990
 151         bool "IBM eServer zSeries model z890 and z990"
 152         help
 153           Select this enable optimizations for model z890/z990.
 154           This will be slightly faster but does not work on
 155           older machines such as the z900.
 156
 157 endchoice
 158
 159 config PACK_STACK
 160         bool "Pack kernel stack"
 161         help
 162           This option enables the compiler option -mkernel-backchain if it
 163           is available. If the option is available the compiler supports
 164           the new stack layout which dramatically reduces the minimum stack
 165           frame size. With an old compiler a non-leaf function needs a
 166           minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
 167           -mkernel-backchain the minimum size drops to 16 byte on 31 bit
 168           and 24 byte on 64 bit.
 169
 170           Say Y if you are unsure.
 171
 172 config SMALL_STACK
 173         bool "Use 4kb/8kb for kernel stack instead of 8kb/16kb"
 174         depends on PACK_STACK
 175         help
 176           If you say Y here and the compiler supports the -mkernel-backchain
 177           option the kernel will use a smaller kernel stack size. For 31 bit
 178           the reduced size is 4kb instead of 8kb and for 64 bit it is 8kb
 179           instead of 16kb. This allows to run more thread on a system and
 180           reduces the pressure on the memory management for higher order
 181           page allocations.
 182
 183           Say N if you are unsure.
 184
 185
 186 config CHECK_STACK
 187         bool "Detect kernel stack overflow"
 188         help
 189           This option enables the compiler option -mstack-guard and
 190           -mstack-size if they are available. If the compiler supports them
 191           it will emit additional code to each function prolog to trigger
 192           an illegal operation if the kernel stack is about to overflow.
 193
 194           Say N if you are unsure.
 195
 196 config STACK_GUARD
 197         int "Size of the guard area (128-1024)"
 198         range 128 1024
 199         depends on CHECK_STACK
 200         default "256"
 201         help
 202           This allows you to specify the size of the guard area at the lower
 203           end of the kernel stack. If the kernel stack points into the guard
 204           area on function entry an illegal operation is triggered. The size
 205           needs to be a power of 2. Please keep in mind that the size of an
 206           interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
 207           The minimum size for the stack guard should be 256 for 31 bit and
 208           512 for 64 bit.
 209
 210 config WARN_STACK
 211         bool "Emit compiler warnings for function with broken stack usage"
 212         help
 213           This option enables the compiler options -mwarn-framesize and
 214           -mwarn-dynamicstack. If the compiler supports these options it
 215           will generate warnings for function which either use alloca or
 216           create a stack frame bigger then CONFIG_WARN_STACK_SIZE.
 217
 218           Say N if you are unsure.
 219
 220 config WARN_STACK_SIZE
 221         int "Maximum frame size considered safe (128-2048)"
 222         range 128 2048
 223         depends on WARN_STACK
 224         default "256"
 225         help
 226           This allows you to specify the maximum frame size a function may
 227           have without the compiler complaining about it.
 228
 229 comment "I/O subsystem configuration"
 230
 231 config MACHCHK_WARNING
 232         bool "Process warning machine checks"
 233         help
 234           Select this option if you want the machine check handler on IBM S/390 or
 235           zSeries to process warning machine checks (e.g. on power failures).
 236           If unsure, say "Y".
 237
 238 config QDIO
 239         tristate "QDIO support"
 240         ---help---
 241           This driver provides the Queued Direct I/O base support for the
 242           IBM S/390 (G5 and G6) and eServer zSeries (z800, z890, z900 and z990).
 243
 244           For details please refer to the documentation provided by IBM at
 245           <http://www10.software.ibm.com/developerworks/opensource/linux390>
 246
 247           To compile this driver as a module, choose M here: the
 248           module will be called qdio.
 249
 250           If unsure, say Y.
 251
 252 config QDIO_PERF_STATS
 253         bool "Performance statistics in /proc"
 254         depends on QDIO
 255         help
 256           Say Y here to get performance statistics in /proc/qdio_perf
 257
 258           If unsure, say N.
 259
 260 config QDIO_DEBUG
 261         bool "Extended debugging information"
 262         depends on QDIO
 263         help
 264           Say Y here to get extended debugging output in /proc/s390dbf/qdio...
 265           Warning: this option reduces the performance of the QDIO module.
 266
 267           If unsure, say N.
 268
 269 comment "Misc"
 270
 271 config PREEMPT
 272         bool "Preemptible Kernel"
 273         help
 274           This option reduces the latency of the kernel when reacting to
 275           real-time or interactive events by allowing a low priority process to
 276           be preempted even if it is in kernel mode executing a system call.
 277           This allows applications to run more reliably even when the system is
 278           under load.
 279
 280           Say N if you are unsure.
 281
 282 config IPL
 283         bool "Builtin IPL record support"
 284         help
 285           If you want to use the produced kernel to IPL directly from a
 286           device, you have to merge a bootsector specific to the device
 287           into the first bytes of the kernel. You will have to select the
 288           IPL device.
 289
 290 choice
 291         prompt "IPL method generated into head.S"
 292         depends on IPL
 293         default IPL_TAPE
 294         help
 295           Select "tape" if you want to IPL the image from a Tape.
 296
 297           Select "vm_reader" if you are running under VM/ESA and want
 298           to IPL the image from the emulated card reader.
 299
 300 config IPL_TAPE
 301         bool "tape"
 302
 303 config IPL_VM
 304         bool "vm_reader"
 305
 306 endchoice
 307
 308 source "fs/Kconfig.binfmt"
 309
 310 config PROCESS_DEBUG
 311         bool "Show crashed user process info"
 312         help
 313           Say Y to print all process fault locations to the console.  This is
 314           a debugging option; you probably do not want to set it unless you
 315           are an S390 port maintainer.
 316
 317 config PFAULT
 318         bool "Pseudo page fault support"
 319         help
 320           Select this option, if you want to use PFAULT pseudo page fault
 321           handling under VM. If running native or in LPAR, this option
 322           has no effect. If your VM does not support PFAULT, PAGEEX
 323           pseudo page fault handling will be used.
 324           Note that VM 4.2 supports PFAULT but has a bug in its
 325           implementation that causes some problems.
 326           Everybody who wants to run Linux under VM != VM4.2 should select
 327           this option.
 328
 329 config SHARED_KERNEL
 330         bool "VM shared kernel support"
 331         help
 332           Select this option, if you want to share the text segment of the
 333           Linux kernel between different VM guests. This reduces memory
 334           usage with lots of guests but greatly increases kernel size.
 335           You should only select this option if you know what you are
 336           doing and want to exploit this feature.
 337
 338 config CMM
 339         tristate "Cooperative memory management"
 340         help
 341           Select this option, if you want to enable the kernel interface
 342           to reduce the memory size of the system. This is accomplished
 343           by allocating pages of memory and put them "on hold". This only
 344           makes sense for a system running under VM where the unused pages
 345           will be reused by VM for other guest systems. The interface
 346           allows an external monitor to balance memory of many systems.
 347           Everybody who wants to run Linux under VM should select this
 348           option.
 349
 350 config CMM_PROC
 351         bool "/proc interface to cooperative memory management"
 352         depends on CMM
 353         help
 354           Select this option to enable the /proc interface to the
 355           cooperative memory management.
 356
 357 config CMM_IUCV
 358         bool "IUCV special message interface to cooperative memory management"
 359         depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
 360         help
 361           Select this option to enable the special message interface to
 362           the cooperative memory management.
 363
 364 config VIRT_TIMER
 365         bool "Virtual CPU timer support"
 366         help
 367           This provides a kernel interface for virtual CPU timers.
 368           Default is disabled.
 369
 370 config VIRT_CPU_ACCOUNTING
 371         bool "Base user process accounting on virtual cpu timer"
 372         depends on VIRT_TIMER
 373         help
 374           Select this option to use CPU timer deltas to do user
 375           process accounting.
 376
 377 config APPLDATA_BASE
 378         bool "Linux - VM Monitor Stream, base infrastructure"
 379         depends on PROC_FS && VIRT_TIMER=y
 380         help
 381           This provides a kernel interface for creating and updating z/VM APPLDATA
 382           monitor records. The monitor records are updated at certain time
 383           intervals, once the timer is started.
 384           Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
 385           i.e. enables or disables monitoring on the Linux side.
 386           A custom interval value (in seconds) can be written to
 387           /proc/appldata/interval.
 388
 389           Defaults are 60 seconds interval and timer off.
 390           The /proc entries can also be read from, showing the current settings.
 391
 392 config APPLDATA_MEM
 393         tristate "Monitor memory management statistics"
 394         depends on APPLDATA_BASE
 395         help
 396           This provides memory management related data to the Linux - VM Monitor
 397           Stream, like paging/swapping rate, memory utilisation, etc.
 398           Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
 399           APPLDATA monitor record, i.e. enables or disables monitoring this record
 400           on the z/VM side.
 401
 402           Default is disabled.
 403           The /proc entry can also be read from, showing the current settings.
 404
 405           This can also be compiled as a module, which will be called
 406           appldata_mem.o.
 407
 408 config APPLDATA_OS
 409         tristate "Monitor OS statistics"
 410         depends on APPLDATA_BASE
 411         help
 412           This provides OS related data to the Linux - VM Monitor Stream, like
 413           CPU utilisation, etc.
 414           Writing 1 or 0 to /proc/appldata/os 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_os.o.
 421
 422 config APPLDATA_NET_SUM
 423         tristate "Monitor overall network statistics"
 424         depends on APPLDATA_BASE
 425         help
 426           This provides network related data to the Linux - VM Monitor Stream,
 427           currently there is only a total sum of network I/O statistics, no
 428           per-interface data.
 429           Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
 430           APPLDATA monitor record, i.e. enables or disables monitoring this record
 431           on the z/VM side.
 432
 433           Default is disabled.
 434           This can also be compiled as a module, which will be called
 435           appldata_net_sum.o.
 436
 437 config NO_IDLE_HZ
 438         bool "No HZ timer ticks in idle"
 439         help
 440           Switches the regular HZ timer off when the system is going idle.
 441           This helps z/VM to detect that the Linux system is idle. VM can
 442           then "swap-out" this guest which reduces memory usage. It also
 443           reduces the overhead of idle systems.
 444
 445           The HZ timer can be switched on/off via /proc/sys/kernel/hz_timer.
 446           hz_timer=0 means HZ timer is disabled. hz_timer=1 means HZ
 447           timer is active.
 448
 449 config NO_IDLE_HZ_INIT
 450         bool "HZ timer in idle off by default"
 451         depends on NO_IDLE_HZ
 452         help
 453           The HZ timer is switched off in idle by default. That means the
 454           HZ timer is already disabled at boot time.
 455
 456 endmenu
 457
 458 config PCMCIA
 459         bool
 460         default n
 461
 462 source "drivers/base/Kconfig"
 463
 464 source "drivers/scsi/Kconfig"
 465
 466 source "drivers/s390/Kconfig"
 467
 468 source "net/Kconfig"
 469
 470 source "fs/Kconfig"
 471
 472 source "arch/s390/oprofile/Kconfig"
 473
 474 source "arch/s390/Kconfig.debug"
 475
 476 source "security/Kconfig"
 477
 478 source "crypto/Kconfig"
 479
 480 source "lib/Kconfig"