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 HAVE_LATENCYTOP_SUPPORT
  20         def_bool y
  21
  22 config RWSEM_GENERIC_SPINLOCK
  23         bool
  24
  25 config RWSEM_XCHGADD_ALGORITHM
  26         def_bool y
  27
  28 config ARCH_HAS_ILOG2_U32
  29         bool
  30         default n
  31
  32 config ARCH_HAS_ILOG2_U64
  33         bool
  34         default n
  35
  36 config GENERIC_HWEIGHT
  37         def_bool y
  38
  39 config GENERIC_TIME
  40         def_bool y
  41
  42 config GENERIC_BUG
  43         bool
  44         depends on BUG
  45         default y
  46
  47 config NO_IOMEM
  48         def_bool y
  49
  50 config NO_DMA
  51         def_bool y
  52
  53 config GENERIC_LOCKBREAK
  54         bool
  55         default y
  56         depends on SMP && PREEMPT
  57
  58 mainmenu "Linux Kernel Configuration"
  59
  60 config S390
  61         def_bool y
  62         select HAVE_OPROFILE
  63         select HAVE_KPROBES
  64         select HAVE_KRETPROBES
  65
  66 source "init/Kconfig"
  67
  68 menu "Base setup"
  69
  70 comment "Processor type and features"
  71
  72 config 64BIT
  73         bool "64 bit kernel"
  74         help
  75           Select this option if you have a 64 bit IBM zSeries machine
  76           and want to use the 64 bit addressing mode.
  77
  78 config 32BIT
  79         bool
  80         default y if !64BIT
  81
  82 config SMP
  83         bool "Symmetric multi-processing support"
  84         ---help---
  85           This enables support for systems with more than one CPU. If you have
  86           a system with only one CPU, like most personal computers, say N. If
  87           you have a system with more than one CPU, say Y.
  88
  89           If you say N here, the kernel will run on single and multiprocessor
  90           machines, but will use only one CPU of a multiprocessor machine. If
  91           you say Y here, the kernel will run on many, but not all,
  92           singleprocessor machines. On a singleprocessor machine, the kernel
  93           will run faster if you say N here.
  94
  95           See also the SMP-HOWTO available at
  96           <http://www.tldp.org/docs.html#howto>.
  97
  98           Even if you don't know what to do here, say Y.
  99
 100 config NR_CPUS
 101         int "Maximum number of CPUs (2-64)"
 102         range 2 64
 103         depends on SMP
 104         default "32" if !64BIT
 105         default "64" if 64BIT
 106         help
 107           This allows you to specify the maximum number of CPUs which this
 108           kernel will support.  The maximum supported value is 64 and the
 109           minimum value which makes sense is 2.
 110
 111           This is purely to save memory - each supported CPU adds
 112           approximately sixteen kilobytes to the kernel image.
 113
 114 config HOTPLUG_CPU
 115         bool "Support for hot-pluggable CPUs"
 116         depends on SMP
 117         select HOTPLUG
 118         default n
 119         help
 120           Say Y here to be able to turn CPUs off and on. CPUs
 121           can be controlled through /sys/devices/system/cpu/cpu#.
 122           Say N if you want to disable CPU hotplug.
 123
 124 config MATHEMU
 125         bool "IEEE FPU emulation"
 126         depends on MARCH_G5
 127         help
 128           This option is required for IEEE compliant floating point arithmetic
 129           on older S/390 machines. Say Y unless you know your machine doesn't
 130           need this.
 131
 132 config COMPAT
 133         bool "Kernel support for 31 bit emulation"
 134         depends on 64BIT
 135         help
 136           Select this option if you want to enable your system kernel to
 137           handle system-calls from ELF binaries for 31 bit ESA.  This option
 138           (and some other stuff like libraries and such) is needed for
 139           executing 31 bit applications.  It is safe to say "Y".
 140
 141 config SYSVIPC_COMPAT
 142         bool
 143         depends on COMPAT && SYSVIPC
 144         default y
 145
 146 config AUDIT_ARCH
 147         bool
 148         default y
 149
 150 config S390_SWITCH_AMODE
 151         bool "Switch kernel/user addressing modes"
 152         help
 153           This option allows to switch the addressing modes of kernel and user
 154           space. The kernel parameter switch_amode=on will enable this feature,
 155           default is disabled. Enabling this (via kernel parameter) on machines
 156           earlier than IBM System z9-109 EC/BC will reduce system performance.
 157
 158           Note that this option will also be selected by selecting the execute
 159           protection option below. Enabling the execute protection via the
 160           noexec kernel parameter will also switch the addressing modes,
 161           independent of the switch_amode kernel parameter.
 162
 163
 164 config S390_EXEC_PROTECT
 165         bool "Data execute protection"
 166         select S390_SWITCH_AMODE
 167         help
 168           This option allows to enable a buffer overflow protection for user
 169           space programs and it also selects the addressing mode option above.
 170           The kernel parameter noexec=on will enable this feature and also
 171           switch the addressing modes, default is disabled. Enabling this (via
 172           kernel parameter) on machines earlier than IBM System z9-109 EC/BC
 173           will reduce system performance.
 174
 175 comment "Code generation options"
 176
 177 choice
 178         prompt "Processor type"
 179         default MARCH_G5
 180
 181 config MARCH_G5
 182         bool "S/390 model G5 and G6"
 183         depends on !64BIT
 184         help
 185           Select this to build a 31 bit kernel that works
 186           on all S/390 and zSeries machines.
 187
 188 config MARCH_Z900
 189         bool "IBM eServer zSeries model z800 and z900"
 190         help
 191           Select this to optimize for zSeries machines. This
 192           will enable some optimizations that are not available
 193           on older 31 bit only CPUs.
 194
 195 config MARCH_Z990
 196         bool "IBM eServer zSeries model z890 and z990"
 197         help
 198           Select this enable optimizations for model z890/z990.
 199           This will be slightly faster but does not work on
 200           older machines such as the z900.
 201
 202 config MARCH_Z9_109
 203         bool "IBM System z9"
 204         help
 205           Select this to enable optimizations for IBM System z9-109, IBM
 206           System z9 Enterprise Class (z9 EC), and IBM System z9 Business
 207           Class (z9 BC). The kernel will be slightly faster but will not
 208           work on older machines such as the z990, z890, z900, and z800.
 209
 210 endchoice
 211
 212 config PACK_STACK
 213         bool "Pack kernel stack"
 214         help
 215           This option enables the compiler option -mkernel-backchain if it
 216           is available. If the option is available the compiler supports
 217           the new stack layout which dramatically reduces the minimum stack
 218           frame size. With an old compiler a non-leaf function needs a
 219           minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
 220           -mkernel-backchain the minimum size drops to 16 byte on 31 bit
 221           and 24 byte on 64 bit.
 222
 223           Say Y if you are unsure.
 224
 225 config SMALL_STACK
 226         bool "Use 4kb/8kb for kernel stack instead of 8kb/16kb"
 227         depends on PACK_STACK && !LOCKDEP
 228         help
 229           If you say Y here and the compiler supports the -mkernel-backchain
 230           option the kernel will use a smaller kernel stack size. For 31 bit
 231           the reduced size is 4kb instead of 8kb and for 64 bit it is 8kb
 232           instead of 16kb. This allows to run more thread on a system and
 233           reduces the pressure on the memory management for higher order
 234           page allocations.
 235
 236           Say N if you are unsure.
 237
 238
 239 config CHECK_STACK
 240         bool "Detect kernel stack overflow"
 241         help
 242           This option enables the compiler option -mstack-guard and
 243           -mstack-size if they are available. If the compiler supports them
 244           it will emit additional code to each function prolog to trigger
 245           an illegal operation if the kernel stack is about to overflow.
 246
 247           Say N if you are unsure.
 248
 249 config STACK_GUARD
 250         int "Size of the guard area (128-1024)"
 251         range 128 1024
 252         depends on CHECK_STACK
 253         default "256"
 254         help
 255           This allows you to specify the size of the guard area at the lower
 256           end of the kernel stack. If the kernel stack points into the guard
 257           area on function entry an illegal operation is triggered. The size
 258           needs to be a power of 2. Please keep in mind that the size of an
 259           interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
 260           The minimum size for the stack guard should be 256 for 31 bit and
 261           512 for 64 bit.
 262
 263 config WARN_STACK
 264         bool "Emit compiler warnings for function with broken stack usage"
 265         help
 266           This option enables the compiler options -mwarn-framesize and
 267           -mwarn-dynamicstack. If the compiler supports these options it
 268           will generate warnings for function which either use alloca or
 269           create a stack frame bigger then CONFIG_WARN_STACK_SIZE.
 270
 271           Say N if you are unsure.
 272
 273 config WARN_STACK_SIZE
 274         int "Maximum frame size considered safe (128-2048)"
 275         range 128 2048
 276         depends on WARN_STACK
 277         default "256"
 278         help
 279           This allows you to specify the maximum frame size a function may
 280           have without the compiler complaining about it.
 281
 282 config ARCH_POPULATES_NODE_MAP
 283         def_bool y
 284
 285 comment "Kernel preemption"
 286
 287 source "kernel/Kconfig.preempt"
 288
 289 source "mm/Kconfig"
 290
 291 comment "I/O subsystem configuration"
 292
 293 config MACHCHK_WARNING
 294         bool "Process warning machine checks"
 295         help
 296           Select this option if you want the machine check handler on IBM S/390 or
 297           zSeries to process warning machine checks (e.g. on power failures).
 298           If unsure, say "Y".
 299
 300 config QDIO
 301         tristate "QDIO support"
 302         ---help---
 303           This driver provides the Queued Direct I/O base support for
 304           IBM mainframes.
 305
 306           For details please refer to the documentation provided by IBM at
 307           <http://www10.software.ibm.com/developerworks/opensource/linux390>
 308
 309           To compile this driver as a module, choose M here: the
 310           module will be called qdio.
 311
 312           If unsure, say Y.
 313
 314 config QDIO_DEBUG
 315         bool "Extended debugging information"
 316         depends on QDIO
 317         help
 318           Say Y here to get extended debugging output in
 319             /sys/kernel/debug/s390dbf/qdio...
 320           Warning: this option reduces the performance of the QDIO module.
 321
 322           If unsure, say N.
 323
 324 comment "Misc"
 325
 326 config IPL
 327         bool "Builtin IPL record support"
 328         help
 329           If you want to use the produced kernel to IPL directly from a
 330           device, you have to merge a bootsector specific to the device
 331           into the first bytes of the kernel. You will have to select the
 332           IPL device.
 333
 334 choice
 335         prompt "IPL method generated into head.S"
 336         depends on IPL
 337         default IPL_TAPE
 338         help
 339           Select "tape" if you want to IPL the image from a Tape.
 340
 341           Select "vm_reader" if you are running under VM/ESA and want
 342           to IPL the image from the emulated card reader.
 343
 344 config IPL_TAPE
 345         bool "tape"
 346
 347 config IPL_VM
 348         bool "vm_reader"
 349
 350 endchoice
 351
 352 source "fs/Kconfig.binfmt"
 353
 354 config FORCE_MAX_ZONEORDER
 355         int
 356         default "9"
 357
 358 config PROCESS_DEBUG
 359         bool "Show crashed user process info"
 360         help
 361           Say Y to print all process fault locations to the console.  This is
 362           a debugging option; you probably do not want to set it unless you
 363           are an S390 port maintainer.
 364
 365 config PFAULT
 366         bool "Pseudo page fault support"
 367         help
 368           Select this option, if you want to use PFAULT pseudo page fault
 369           handling under VM. If running native or in LPAR, this option
 370           has no effect. If your VM does not support PFAULT, PAGEEX
 371           pseudo page fault handling will be used.
 372           Note that VM 4.2 supports PFAULT but has a bug in its
 373           implementation that causes some problems.
 374           Everybody who wants to run Linux under VM != VM4.2 should select
 375           this option.
 376
 377 config SHARED_KERNEL
 378         bool "VM shared kernel support"
 379         help
 380           Select this option, if you want to share the text segment of the
 381           Linux kernel between different VM guests. This reduces memory
 382           usage with lots of guests but greatly increases kernel size.
 383           Also if a kernel was IPL'ed from a shared segment the kexec system
 384           call will not work.
 385           You should only select this option if you know what you are
 386           doing and want to exploit this feature.
 387
 388 config CMM
 389         tristate "Cooperative memory management"
 390         help
 391           Select this option, if you want to enable the kernel interface
 392           to reduce the memory size of the system. This is accomplished
 393           by allocating pages of memory and put them "on hold". This only
 394           makes sense for a system running under VM where the unused pages
 395           will be reused by VM for other guest systems. The interface
 396           allows an external monitor to balance memory of many systems.
 397           Everybody who wants to run Linux under VM should select this
 398           option.
 399
 400 config CMM_PROC
 401         bool "/proc interface to cooperative memory management"
 402         depends on CMM
 403         help
 404           Select this option to enable the /proc interface to the
 405           cooperative memory management.
 406
 407 config CMM_IUCV
 408         bool "IUCV special message interface to cooperative memory management"
 409         depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
 410         help
 411           Select this option to enable the special message interface to
 412           the cooperative memory management.
 413
 414 config VIRT_TIMER
 415         bool "Virtual CPU timer support"
 416         help
 417           This provides a kernel interface for virtual CPU timers.
 418           Default is disabled.
 419
 420 config VIRT_CPU_ACCOUNTING
 421         bool "Base user process accounting on virtual cpu timer"
 422         depends on VIRT_TIMER
 423         help
 424           Select this option to use CPU timer deltas to do user
 425           process accounting.
 426
 427 config APPLDATA_BASE
 428         bool "Linux - VM Monitor Stream, base infrastructure"
 429         depends on PROC_FS && VIRT_TIMER=y
 430         help
 431           This provides a kernel interface for creating and updating z/VM APPLDATA
 432           monitor records. The monitor records are updated at certain time
 433           intervals, once the timer is started.
 434           Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
 435           i.e. enables or disables monitoring on the Linux side.
 436           A custom interval value (in seconds) can be written to
 437           /proc/appldata/interval.
 438
 439           Defaults are 60 seconds interval and timer off.
 440           The /proc entries can also be read from, showing the current settings.
 441
 442 config APPLDATA_MEM
 443         tristate "Monitor memory management statistics"
 444         depends on APPLDATA_BASE && VM_EVENT_COUNTERS
 445         help
 446           This provides memory management related data to the Linux - VM Monitor
 447           Stream, like paging/swapping rate, memory utilisation, etc.
 448           Writing 1 or 0 to /proc/appldata/memory 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           The /proc entry can also be read from, showing the current settings.
 454
 455           This can also be compiled as a module, which will be called
 456           appldata_mem.o.
 457
 458 config APPLDATA_OS
 459         tristate "Monitor OS statistics"
 460         depends on APPLDATA_BASE
 461         help
 462           This provides OS related data to the Linux - VM Monitor Stream, like
 463           CPU utilisation, etc.
 464           Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
 465           APPLDATA monitor record, i.e. enables or disables monitoring this record
 466           on the z/VM side.
 467
 468           Default is disabled.
 469           This can also be compiled as a module, which will be called
 470           appldata_os.o.
 471
 472 config APPLDATA_NET_SUM
 473         tristate "Monitor overall network statistics"
 474         depends on APPLDATA_BASE
 475         help
 476           This provides network related data to the Linux - VM Monitor Stream,
 477           currently there is only a total sum of network I/O statistics, no
 478           per-interface data.
 479           Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
 480           APPLDATA monitor record, i.e. enables or disables monitoring this record
 481           on the z/VM side.
 482
 483           Default is disabled.
 484           This can also be compiled as a module, which will be called
 485           appldata_net_sum.o.
 486
 487 source kernel/Kconfig.hz
 488
 489 config NO_IDLE_HZ
 490         bool "No HZ timer ticks in idle"
 491         help
 492           Switches the regular HZ timer off when the system is going idle.
 493           This helps z/VM to detect that the Linux system is idle. VM can
 494           then "swap-out" this guest which reduces memory usage. It also
 495           reduces the overhead of idle systems.
 496
 497           The HZ timer can be switched on/off via /proc/sys/kernel/hz_timer.
 498           hz_timer=0 means HZ timer is disabled. hz_timer=1 means HZ
 499           timer is active.
 500
 501 config NO_IDLE_HZ_INIT
 502         bool "HZ timer in idle off by default"
 503         depends on NO_IDLE_HZ
 504         help
 505           The HZ timer is switched off in idle by default. That means the
 506           HZ timer is already disabled at boot time.
 507
 508 config S390_HYPFS_FS
 509         bool "s390 hypervisor file system support"
 510         select SYS_HYPERVISOR
 511         default y
 512         help
 513           This is a virtual file system intended to provide accounting
 514           information in an s390 hypervisor environment.
 515
 516 config KEXEC
 517         bool "kexec system call"
 518         help
 519           kexec is a system call that implements the ability to shutdown your
 520           current kernel, and to start another kernel.  It is like a reboot
 521           but is independent of hardware/microcode support.
 522
 523 config ZFCPDUMP
 524         tristate "zfcpdump support"
 525         select SMP
 526         default n
 527         help
 528           Select this option if you want to build an zfcpdump enabled kernel.
 529           Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
 530
 531 endmenu
 532
 533 source "net/Kconfig"
 534
 535 config PCMCIA
 536         def_bool n
 537
 538 config CCW
 539         def_bool y
 540
 541 source "drivers/Kconfig"
 542
 543 source "fs/Kconfig"
 544
 545 source "arch/s390/Kconfig.debug"
 546
 547 source "security/Kconfig"
 548
 549 source "crypto/Kconfig"
 550
 551 source "lib/Kconfig"