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