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 source "mm/Kconfig"
 245
 246 comment "I/O subsystem configuration"
 247
 248 config MACHCHK_WARNING
 249         bool "Process warning machine checks"
 250         help
 251           Select this option if you want the machine check handler on IBM S/390 or
 252           zSeries to process warning machine checks (e.g. on power failures).
 253           If unsure, say "Y".
 254
 255 config QDIO
 256         tristate "QDIO support"
 257         ---help---
 258           This driver provides the Queued Direct I/O base support for
 259           IBM mainframes.
 260
 261           For details please refer to the documentation provided by IBM at
 262           <http://www10.software.ibm.com/developerworks/opensource/linux390>
 263
 264           To compile this driver as a module, choose M here: the
 265           module will be called qdio.
 266
 267           If unsure, say Y.
 268
 269 config QDIO_PERF_STATS
 270         bool "Performance statistics in /proc"
 271         depends on QDIO
 272         help
 273           Say Y here to get performance statistics in /proc/qdio_perf
 274
 275           If unsure, say N.
 276
 277 config QDIO_DEBUG
 278         bool "Extended debugging information"
 279         depends on QDIO
 280         help
 281           Say Y here to get extended debugging output in
 282             /sys/kernel/debug/s390dbf/qdio...
 283           Warning: this option reduces the performance of the QDIO module.
 284
 285           If unsure, say N.
 286
 287 comment "Misc"
 288
 289 config PREEMPT
 290         bool "Preemptible Kernel"
 291         help
 292           This option reduces the latency of the kernel when reacting to
 293           real-time or interactive events by allowing a low priority process to
 294           be preempted even if it is in kernel mode executing a system call.
 295           This allows applications to run more reliably even when the system is
 296           under load.
 297
 298           Say N if you are unsure.
 299
 300 config IPL
 301         bool "Builtin IPL record support"
 302         help
 303           If you want to use the produced kernel to IPL directly from a
 304           device, you have to merge a bootsector specific to the device
 305           into the first bytes of the kernel. You will have to select the
 306           IPL device.
 307
 308 choice
 309         prompt "IPL method generated into head.S"
 310         depends on IPL
 311         default IPL_TAPE
 312         help
 313           Select "tape" if you want to IPL the image from a Tape.
 314
 315           Select "vm_reader" if you are running under VM/ESA and want
 316           to IPL the image from the emulated card reader.
 317
 318 config IPL_TAPE
 319         bool "tape"
 320
 321 config IPL_VM
 322         bool "vm_reader"
 323
 324 endchoice
 325
 326 source "fs/Kconfig.binfmt"
 327
 328 config PROCESS_DEBUG
 329         bool "Show crashed user process info"
 330         help
 331           Say Y to print all process fault locations to the console.  This is
 332           a debugging option; you probably do not want to set it unless you
 333           are an S390 port maintainer.
 334
 335 config PFAULT
 336         bool "Pseudo page fault support"
 337         help
 338           Select this option, if you want to use PFAULT pseudo page fault
 339           handling under VM. If running native or in LPAR, this option
 340           has no effect. If your VM does not support PFAULT, PAGEEX
 341           pseudo page fault handling will be used.
 342           Note that VM 4.2 supports PFAULT but has a bug in its
 343           implementation that causes some problems.
 344           Everybody who wants to run Linux under VM != VM4.2 should select
 345           this option.
 346
 347 config SHARED_KERNEL
 348         bool "VM shared kernel support"
 349         help
 350           Select this option, if you want to share the text segment of the
 351           Linux kernel between different VM guests. This reduces memory
 352           usage with lots of guests but greatly increases kernel size.
 353           You should only select this option if you know what you are
 354           doing and want to exploit this feature.
 355
 356 config CMM
 357         tristate "Cooperative memory management"
 358         help
 359           Select this option, if you want to enable the kernel interface
 360           to reduce the memory size of the system. This is accomplished
 361           by allocating pages of memory and put them "on hold". This only
 362           makes sense for a system running under VM where the unused pages
 363           will be reused by VM for other guest systems. The interface
 364           allows an external monitor to balance memory of many systems.
 365           Everybody who wants to run Linux under VM should select this
 366           option.
 367
 368 config CMM_PROC
 369         bool "/proc interface to cooperative memory management"
 370         depends on CMM
 371         help
 372           Select this option to enable the /proc interface to the
 373           cooperative memory management.
 374
 375 config CMM_IUCV
 376         bool "IUCV special message interface to cooperative memory management"
 377         depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
 378         help
 379           Select this option to enable the special message interface to
 380           the cooperative memory management.
 381
 382 config VIRT_TIMER
 383         bool "Virtual CPU timer support"
 384         help
 385           This provides a kernel interface for virtual CPU timers.
 386           Default is disabled.
 387
 388 config VIRT_CPU_ACCOUNTING
 389         bool "Base user process accounting on virtual cpu timer"
 390         depends on VIRT_TIMER
 391         help
 392           Select this option to use CPU timer deltas to do user
 393           process accounting.
 394
 395 config APPLDATA_BASE
 396         bool "Linux - VM Monitor Stream, base infrastructure"
 397         depends on PROC_FS && VIRT_TIMER=y
 398         help
 399           This provides a kernel interface for creating and updating z/VM APPLDATA
 400           monitor records. The monitor records are updated at certain time
 401           intervals, once the timer is started.
 402           Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
 403           i.e. enables or disables monitoring on the Linux side.
 404           A custom interval value (in seconds) can be written to
 405           /proc/appldata/interval.
 406
 407           Defaults are 60 seconds interval and timer off.
 408           The /proc entries can also be read from, showing the current settings.
 409
 410 config APPLDATA_MEM
 411         tristate "Monitor memory management statistics"
 412         depends on APPLDATA_BASE
 413         help
 414           This provides memory management related data to the Linux - VM Monitor
 415           Stream, like paging/swapping rate, memory utilisation, etc.
 416           Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
 417           APPLDATA monitor record, i.e. enables or disables monitoring this record
 418           on the z/VM side.
 419
 420           Default is disabled.
 421           The /proc entry can also be read from, showing the current settings.
 422
 423           This can also be compiled as a module, which will be called
 424           appldata_mem.o.
 425
 426 config APPLDATA_OS
 427         tristate "Monitor OS statistics"
 428         depends on APPLDATA_BASE
 429         help
 430           This provides OS related data to the Linux - VM Monitor Stream, like
 431           CPU utilisation, etc.
 432           Writing 1 or 0 to /proc/appldata/os 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           This can also be compiled as a module, which will be called
 438           appldata_os.o.
 439
 440 config APPLDATA_NET_SUM
 441         tristate "Monitor overall network statistics"
 442         depends on APPLDATA_BASE
 443         help
 444           This provides network related data to the Linux - VM Monitor Stream,
 445           currently there is only a total sum of network I/O statistics, no
 446           per-interface data.
 447           Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
 448           APPLDATA monitor record, i.e. enables or disables monitoring this record
 449           on the z/VM side.
 450
 451           Default is disabled.
 452           This can also be compiled as a module, which will be called
 453           appldata_net_sum.o.
 454
 455 config NO_IDLE_HZ
 456         bool "No HZ timer ticks in idle"
 457         help
 458           Switches the regular HZ timer off when the system is going idle.
 459           This helps z/VM to detect that the Linux system is idle. VM can
 460           then "swap-out" this guest which reduces memory usage. It also
 461           reduces the overhead of idle systems.
 462
 463           The HZ timer can be switched on/off via /proc/sys/kernel/hz_timer.
 464           hz_timer=0 means HZ timer is disabled. hz_timer=1 means HZ
 465           timer is active.
 466
 467 config NO_IDLE_HZ_INIT
 468         bool "HZ timer in idle off by default"
 469         depends on NO_IDLE_HZ
 470         help
 471           The HZ timer is switched off in idle by default. That means the
 472           HZ timer is already disabled at boot time.
 473
 474 config S390_HYPFS_FS
 475         bool "s390 hypervisor file system support"
 476         select SYS_HYPERVISOR
 477         default y
 478         help
 479           This is a virtual file system intended to provide accounting
 480           information in an s390 hypervisor environment.
 481
 482 config KEXEC
 483         bool "kexec system call"
 484         help
 485           kexec is a system call that implements the ability to shutdown your
 486           current kernel, and to start another kernel.  It is like a reboot
 487           but is independent of hardware/microcode support.
 488
 489 endmenu
 490
 491 source "net/Kconfig"
 492
 493 config PCMCIA
 494         bool
 495         default n
 496
 497 source "drivers/base/Kconfig"
 498
 499 source "drivers/connector/Kconfig"
 500
 501 source "drivers/scsi/Kconfig"
 502
 503 source "drivers/s390/Kconfig"
 504
 505 source "drivers/net/Kconfig"
 506
 507 source "fs/Kconfig"
 508
 509 menu "Instrumentation Support"
 510
 511 source "arch/s390/oprofile/Kconfig"
 512
 513 config KPROBES
 514         bool "Kprobes (EXPERIMENTAL)"
 515         depends on EXPERIMENTAL && MODULES
 516         help
 517           Kprobes allows you to trap at almost any kernel address and
 518           execute a callback function.  register_kprobe() establishes
 519           a probepoint and specifies the callback.  Kprobes is useful
 520           for kernel debugging, non-intrusive instrumentation and testing.
 521           If in doubt, say "N".
 522
 523 endmenu
 524
 525 source "arch/s390/Kconfig.debug"
 526
 527 source "security/Kconfig"
 528
 529 source "crypto/Kconfig"
 530
 531 source "lib/Kconfig"