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 SCHED_MC
   7         def_bool y
   8         depends on SMP
   9
  10 config MMU
  11         def_bool y
  12
  13 config ZONE_DMA
  14         def_bool y
  15         depends on 64BIT
  16
  17 config LOCKDEP_SUPPORT
  18         def_bool y
  19
  20 config STACKTRACE_SUPPORT
  21         def_bool y
  22
  23 config HAVE_LATENCYTOP_SUPPORT
  24         def_bool y
  25
  26 config RWSEM_GENERIC_SPINLOCK
  27         bool
  28
  29 config RWSEM_XCHGADD_ALGORITHM
  30         def_bool y
  31
  32 config ARCH_HAS_ILOG2_U32
  33         bool
  34         default n
  35
  36 config ARCH_HAS_ILOG2_U64
  37         bool
  38         default n
  39
  40 config GENERIC_HWEIGHT
  41         def_bool y
  42
  43 config GENERIC_TIME
  44         def_bool y
  45
  46 config GENERIC_BUG
  47         bool
  48         depends on BUG
  49         default y
  50
  51 config NO_IOMEM
  52         def_bool y
  53
  54 config NO_DMA
  55         def_bool y
  56
  57 config GENERIC_LOCKBREAK
  58         bool
  59         default y
  60         depends on SMP && PREEMPT
  61
  62 mainmenu "Linux Kernel Configuration"
  63
  64 config S390
  65         def_bool y
  66         select HAVE_OPROFILE
  67         select HAVE_KPROBES
  68         select HAVE_KRETPROBES
  69
  70 source "init/Kconfig"
  71
  72 menu "Base setup"
  73
  74 comment "Processor type and features"
  75
  76 config 64BIT
  77         bool "64 bit kernel"
  78         help
  79           Select this option if you have a 64 bit IBM zSeries machine
  80           and want to use the 64 bit addressing mode.
  81
  82 config 32BIT
  83         bool
  84         default y if !64BIT
  85
  86 config SMP
  87         bool "Symmetric multi-processing support"
  88         ---help---
  89           This enables support for systems with more than one CPU. If you have
  90           a system with only one CPU, like most personal computers, say N. If
  91           you have a system with more than one CPU, say Y.
  92
  93           If you say N here, the kernel will run on single and multiprocessor
  94           machines, but will use only one CPU of a multiprocessor machine. If
  95           you say Y here, the kernel will run on many, but not all,
  96           singleprocessor machines. On a singleprocessor machine, the kernel
  97           will run faster if you say N here.
  98
  99           See also the SMP-HOWTO available at
 100           <http://www.tldp.org/docs.html#howto>.
 101
 102           Even if you don't know what to do here, say Y.
 103
 104 config NR_CPUS
 105         int "Maximum number of CPUs (2-64)"
 106         range 2 64
 107         depends on SMP
 108         default "32" if !64BIT
 109         default "64" if 64BIT
 110         help
 111           This allows you to specify the maximum number of CPUs which this
 112           kernel will support.  The maximum supported value is 64 and the
 113           minimum value which makes sense is 2.
 114
 115           This is purely to save memory - each supported CPU adds
 116           approximately sixteen kilobytes to the kernel image.
 117
 118 config HOTPLUG_CPU
 119         bool "Support for hot-pluggable CPUs"
 120         depends on SMP
 121         select HOTPLUG
 122         default n
 123         help
 124           Say Y here to be able to turn CPUs off and on. CPUs
 125           can be controlled through /sys/devices/system/cpu/cpu#.
 126           Say N if you want to disable CPU hotplug.
 127
 128 config MATHEMU
 129         bool "IEEE FPU emulation"
 130         depends on MARCH_G5
 131         help
 132           This option is required for IEEE compliant floating point arithmetic
 133           on older S/390 machines. Say Y unless you know your machine doesn't
 134           need this.
 135
 136 config COMPAT
 137         bool "Kernel support for 31 bit emulation"
 138         depends on 64BIT
 139         help
 140           Select this option if you want to enable your system kernel to
 141           handle system-calls from ELF binaries for 31 bit ESA.  This option
 142           (and some other stuff like libraries and such) is needed for
 143           executing 31 bit applications.  It is safe to say "Y".
 144
 145 config SYSVIPC_COMPAT
 146         bool
 147         depends on COMPAT && SYSVIPC
 148         default y
 149
 150 config AUDIT_ARCH
 151         bool
 152         default y
 153
 154 config S390_SWITCH_AMODE
 155         bool "Switch kernel/user addressing modes"
 156         help
 157           This option allows to switch the addressing modes of kernel and user
 158           space. The kernel parameter switch_amode=on will enable this feature,
 159           default is disabled. Enabling this (via kernel parameter) on machines
 160           earlier than IBM System z9-109 EC/BC will reduce system performance.
 161
 162           Note that this option will also be selected by selecting the execute
 163           protection option below. Enabling the execute protection via the
 164           noexec kernel parameter will also switch the addressing modes,
 165           independent of the switch_amode kernel parameter.
 166
 167
 168 config S390_EXEC_PROTECT
 169         bool "Data execute protection"
 170         select S390_SWITCH_AMODE
 171         help
 172           This option allows to enable a buffer overflow protection for user
 173           space programs and it also selects the addressing mode option above.
 174           The kernel parameter noexec=on will enable this feature and also
 175           switch the addressing modes, default is disabled. Enabling this (via
 176           kernel parameter) on machines earlier than IBM System z9-109 EC/BC
 177           will reduce system performance.
 178
 179 comment "Code generation options"
 180
 181 choice
 182         prompt "Processor type"
 183         default MARCH_G5
 184
 185 config MARCH_G5
 186         bool "S/390 model G5 and G6"
 187         depends on !64BIT
 188         help
 189           Select this to build a 31 bit kernel that works
 190           on all S/390 and zSeries machines.
 191
 192 config MARCH_Z900
 193         bool "IBM eServer zSeries model z800 and z900"
 194         help
 195           Select this to optimize for zSeries machines. This
 196           will enable some optimizations that are not available
 197           on older 31 bit only CPUs.
 198
 199 config MARCH_Z990
 200         bool "IBM eServer zSeries model z890 and z990"
 201         help
 202           Select this enable optimizations for model z890/z990.
 203           This will be slightly faster but does not work on
 204           older machines such as the z900.
 205
 206 config MARCH_Z9_109
 207         bool "IBM System z9"
 208         help
 209           Select this to enable optimizations for IBM System z9-109, IBM
 210           System z9 Enterprise Class (z9 EC), and IBM System z9 Business
 211           Class (z9 BC). The kernel will be slightly faster but will not
 212           work on older machines such as the z990, z890, z900, and z800.
 213
 214 endchoice
 215
 216 config PACK_STACK
 217         bool "Pack kernel stack"
 218         help
 219           This option enables the compiler option -mkernel-backchain if it
 220           is available. If the option is available the compiler supports
 221           the new stack layout which dramatically reduces the minimum stack
 222           frame size. With an old compiler a non-leaf function needs a
 223           minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
 224           -mkernel-backchain the minimum size drops to 16 byte on 31 bit
 225           and 24 byte on 64 bit.
 226
 227           Say Y if you are unsure.
 228
 229 config SMALL_STACK
 230         bool "Use 4kb/8kb for kernel stack instead of 8kb/16kb"
 231         depends on PACK_STACK && !LOCKDEP
 232         help
 233           If you say Y here and the compiler supports the -mkernel-backchain
 234           option the kernel will use a smaller kernel stack size. For 31 bit
 235           the reduced size is 4kb instead of 8kb and for 64 bit it is 8kb
 236           instead of 16kb. This allows to run more thread on a system and
 237           reduces the pressure on the memory management for higher order
 238           page allocations.
 239
 240           Say N if you are unsure.
 241
 242
 243 config CHECK_STACK
 244         bool "Detect kernel stack overflow"
 245         help
 246           This option enables the compiler option -mstack-guard and
 247           -mstack-size if they are available. If the compiler supports them
 248           it will emit additional code to each function prolog to trigger
 249           an illegal operation if the kernel stack is about to overflow.
 250
 251           Say N if you are unsure.
 252
 253 config STACK_GUARD
 254         int "Size of the guard area (128-1024)"
 255         range 128 1024
 256         depends on CHECK_STACK
 257         default "256"
 258         help
 259           This allows you to specify the size of the guard area at the lower
 260           end of the kernel stack. If the kernel stack points into the guard
 261           area on function entry an illegal operation is triggered. The size
 262           needs to be a power of 2. Please keep in mind that the size of an
 263           interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
 264           The minimum size for the stack guard should be 256 for 31 bit and
 265           512 for 64 bit.
 266
 267 config WARN_STACK
 268         bool "Emit compiler warnings for function with broken stack usage"
 269         help
 270           This option enables the compiler options -mwarn-framesize and
 271           -mwarn-dynamicstack. If the compiler supports these options it
 272           will generate warnings for function which either use alloca or
 273           create a stack frame bigger then CONFIG_WARN_STACK_SIZE.
 274
 275           Say N if you are unsure.
 276
 277 config WARN_STACK_SIZE
 278         int "Maximum frame size considered safe (128-2048)"
 279         range 128 2048
 280         depends on WARN_STACK
 281         default "256"
 282         help
 283           This allows you to specify the maximum frame size a function may
 284           have without the compiler complaining about it.
 285
 286 config ARCH_POPULATES_NODE_MAP
 287         def_bool y
 288
 289 comment "Kernel preemption"
 290
 291 source "kernel/Kconfig.preempt"
 292
 293 source "mm/Kconfig"
 294
 295 comment "I/O subsystem configuration"
 296
 297 config MACHCHK_WARNING
 298         bool "Process warning machine checks"
 299         help
 300           Select this option if you want the machine check handler on IBM S/390 or
 301           zSeries to process warning machine checks (e.g. on power failures).
 302           If unsure, say "Y".
 303
 304 config QDIO
 305         tristate "QDIO support"
 306         ---help---
 307           This driver provides the Queued Direct I/O base support for
 308           IBM System z.
 309
 310           To compile this driver as a module, choose M here: the
 311           module will be called qdio.
 312
 313           If unsure, say Y.
 314
 315 config QDIO_DEBUG
 316         bool "Extended debugging information"
 317         depends on QDIO
 318         help
 319           Say Y here to get extended debugging output in
 320             /sys/kernel/debug/s390dbf/qdio...
 321           Warning: this option reduces the performance of the QDIO module.
 322
 323           If unsure, say N.
 324
 325 comment "Misc"
 326
 327 config IPL
 328         bool "Builtin IPL record support"
 329         help
 330           If you want to use the produced kernel to IPL directly from a
 331           device, you have to merge a bootsector specific to the device
 332           into the first bytes of the kernel. You will have to select the
 333           IPL device.
 334
 335 choice
 336         prompt "IPL method generated into head.S"
 337         depends on IPL
 338         default IPL_TAPE
 339         help
 340           Select "tape" if you want to IPL the image from a Tape.
 341
 342           Select "vm_reader" if you are running under VM/ESA and want
 343           to IPL the image from the emulated card reader.
 344
 345 config IPL_TAPE
 346         bool "tape"
 347
 348 config IPL_VM
 349         bool "vm_reader"
 350
 351 endchoice
 352
 353 source "fs/Kconfig.binfmt"
 354
 355 config FORCE_MAX_ZONEORDER
 356         int
 357         default "9"
 358
 359 config PROCESS_DEBUG
 360         bool "Show crashed user process info"
 361         help
 362           Say Y to print all process fault locations to the console.  This is
 363           a debugging option; you probably do not want to set it unless you
 364           are an S390 port maintainer.
 365
 366 config PFAULT
 367         bool "Pseudo page fault support"
 368         help
 369           Select this option, if you want to use PFAULT pseudo page fault
 370           handling under VM. If running native or in LPAR, this option
 371           has no effect. If your VM does not support PFAULT, PAGEEX
 372           pseudo page fault handling will be used.
 373           Note that VM 4.2 supports PFAULT but has a bug in its
 374           implementation that causes some problems.
 375           Everybody who wants to run Linux under VM != VM4.2 should select
 376           this option.
 377
 378 config SHARED_KERNEL
 379         bool "VM shared kernel support"
 380         help
 381           Select this option, if you want to share the text segment of the
 382           Linux kernel between different VM guests. This reduces memory
 383           usage with lots of guests but greatly increases kernel size.
 384           Also if a kernel was IPL'ed from a shared segment the kexec system
 385           call will not work.
 386           You should only select this option if you know what you are
 387           doing and want to exploit this feature.
 388
 389 config CMM
 390         tristate "Cooperative memory management"
 391         help
 392           Select this option, if you want to enable the kernel interface
 393           to reduce the memory size of the system. This is accomplished
 394           by allocating pages of memory and put them "on hold". This only
 395           makes sense for a system running under VM where the unused pages
 396           will be reused by VM for other guest systems. The interface
 397           allows an external monitor to balance memory of many systems.
 398           Everybody who wants to run Linux under VM should select this
 399           option.
 400
 401 config CMM_PROC
 402         bool "/proc interface to cooperative memory management"
 403         depends on CMM
 404         help
 405           Select this option to enable the /proc interface to the
 406           cooperative memory management.
 407
 408 config CMM_IUCV
 409         bool "IUCV special message interface to cooperative memory management"
 410         depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
 411         help
 412           Select this option to enable the special message interface to
 413           the cooperative memory management.
 414
 415 config VIRT_TIMER
 416         bool "Virtual CPU timer support"
 417         help
 418           This provides a kernel interface for virtual CPU timers.
 419           Default is disabled.
 420
 421 config VIRT_CPU_ACCOUNTING
 422         bool "Base user process accounting on virtual cpu timer"
 423         depends on VIRT_TIMER
 424         help
 425           Select this option to use CPU timer deltas to do user
 426           process accounting.
 427
 428 config APPLDATA_BASE
 429         bool "Linux - VM Monitor Stream, base infrastructure"
 430         depends on PROC_FS && VIRT_TIMER=y
 431         help
 432           This provides a kernel interface for creating and updating z/VM APPLDATA
 433           monitor records. The monitor records are updated at certain time
 434           intervals, once the timer is started.
 435           Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
 436           i.e. enables or disables monitoring on the Linux side.
 437           A custom interval value (in seconds) can be written to
 438           /proc/appldata/interval.
 439
 440           Defaults are 60 seconds interval and timer off.
 441           The /proc entries can also be read from, showing the current settings.
 442
 443 config APPLDATA_MEM
 444         tristate "Monitor memory management statistics"
 445         depends on APPLDATA_BASE && VM_EVENT_COUNTERS
 446         help
 447           This provides memory management related data to the Linux - VM Monitor
 448           Stream, like paging/swapping rate, memory utilisation, etc.
 449           Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
 450           APPLDATA monitor record, i.e. enables or disables monitoring this record
 451           on the z/VM side.
 452
 453           Default is disabled.
 454           The /proc entry can also be read from, showing the current settings.
 455
 456           This can also be compiled as a module, which will be called
 457           appldata_mem.o.
 458
 459 config APPLDATA_OS
 460         tristate "Monitor OS statistics"
 461         depends on APPLDATA_BASE
 462         help
 463           This provides OS related data to the Linux - VM Monitor Stream, like
 464           CPU utilisation, etc.
 465           Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
 466           APPLDATA monitor record, i.e. enables or disables monitoring this record
 467           on the z/VM side.
 468
 469           Default is disabled.
 470           This can also be compiled as a module, which will be called
 471           appldata_os.o.
 472
 473 config APPLDATA_NET_SUM
 474         tristate "Monitor overall network statistics"
 475         depends on APPLDATA_BASE
 476         help
 477           This provides network related data to the Linux - VM Monitor Stream,
 478           currently there is only a total sum of network I/O statistics, no
 479           per-interface data.
 480           Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
 481           APPLDATA monitor record, i.e. enables or disables monitoring this record
 482           on the z/VM side.
 483
 484           Default is disabled.
 485           This can also be compiled as a module, which will be called
 486           appldata_net_sum.o.
 487
 488 source kernel/Kconfig.hz
 489
 490 config NO_IDLE_HZ
 491         bool "No HZ timer ticks in idle"
 492         help
 493           Switches the regular HZ timer off when the system is going idle.
 494           This helps z/VM to detect that the Linux system is idle. VM can
 495           then "swap-out" this guest which reduces memory usage. It also
 496           reduces the overhead of idle systems.
 497
 498           The HZ timer can be switched on/off via /proc/sys/kernel/hz_timer.
 499           hz_timer=0 means HZ timer is disabled. hz_timer=1 means HZ
 500           timer is active.
 501
 502 config NO_IDLE_HZ_INIT
 503         bool "HZ timer in idle off by default"
 504         depends on NO_IDLE_HZ
 505         help
 506           The HZ timer is switched off in idle by default. That means the
 507           HZ timer is already disabled at boot time.
 508
 509 config S390_HYPFS_FS
 510         bool "s390 hypervisor file system support"
 511         select SYS_HYPERVISOR
 512         default y
 513         help
 514           This is a virtual file system intended to provide accounting
 515           information in an s390 hypervisor environment.
 516
 517 config KEXEC
 518         bool "kexec system call"
 519         help
 520           kexec is a system call that implements the ability to shutdown your
 521           current kernel, and to start another kernel.  It is like a reboot
 522           but is independent of hardware/microcode support.
 523
 524 config ZFCPDUMP
 525         tristate "zfcpdump support"
 526         select SMP
 527         default n
 528         help
 529           Select this option if you want to build an zfcpdump enabled kernel.
 530           Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
 531
 532 endmenu
 533
 534 source "net/Kconfig"
 535
 536 config PCMCIA
 537         def_bool n
 538
 539 config CCW
 540         def_bool y
 541
 542 source "drivers/Kconfig"
 543
 544 source "fs/Kconfig"
 545
 546 source "arch/s390/Kconfig.debug"
 547
 548 source "security/Kconfig"
 549
 550 source "crypto/Kconfig"
 551
 552 source "lib/Kconfig"