VT notifier fix for VT switch
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / s390 / Kconfig
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1#
2# For a description of the syntax of this configuration file,
3# see Documentation/kbuild/kconfig-language.txt.
4#
5
6config MMU
61d48c2c 7 def_bool y
1da177e4 8
66701b14 9config ZONE_DMA
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10 def_bool y
11 depends on 64BIT
66701b14 12
2b105ff9 13config LOCKDEP_SUPPORT
61d48c2c 14 def_bool y
2b105ff9 15
5bdc9b44 16config STACKTRACE_SUPPORT
61d48c2c 17 def_bool y
5bdc9b44 18
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19config HAVE_LATENCYTOP_SUPPORT
20 def_bool y
21
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22config RWSEM_GENERIC_SPINLOCK
23 bool
24
25config RWSEM_XCHGADD_ALGORITHM
61d48c2c 26 def_bool y
1da177e4 27
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28config ARCH_HAS_ILOG2_U32
29 bool
30 default n
31
32config ARCH_HAS_ILOG2_U64
33 bool
34 default n
35
7e33db4e 36config GENERIC_HWEIGHT
61d48c2c 37 def_bool y
7e33db4e 38
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39config GENERIC_TIME
40 def_bool y
41
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42config GENERIC_BUG
43 bool
44 depends on BUG
45 default y
46
23db764d 47config NO_IOMEM
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48 def_bool y
49
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50config NO_DMA
51 def_bool y
52
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53config GENERIC_LOCKBREAK
54 bool
55 default y
56 depends on SMP && PREEMPT
57
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58mainmenu "Linux Kernel Configuration"
59
347a8dc3 60config S390
61d48c2c 61 def_bool y
42d4b839 62 select HAVE_OPROFILE
3f550096 63 select HAVE_KPROBES
1da177e4 64
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65source "init/Kconfig"
66
67menu "Base setup"
68
69comment "Processor type and features"
70
347a8dc3 71config 64BIT
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72 bool "64 bit kernel"
73 help
74 Select this option if you have a 64 bit IBM zSeries machine
75 and want to use the 64 bit addressing mode.
76
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77config 32BIT
78 bool
79 default y if !64BIT
80
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81config SMP
82 bool "Symmetric multi-processing support"
83 ---help---
84 This enables support for systems with more than one CPU. If you have
85 a system with only one CPU, like most personal computers, say N. If
86 you have a system with more than one CPU, say Y.
87
88 If you say N here, the kernel will run on single and multiprocessor
89 machines, but will use only one CPU of a multiprocessor machine. If
90 you say Y here, the kernel will run on many, but not all,
91 singleprocessor machines. On a singleprocessor machine, the kernel
92 will run faster if you say N here.
93
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94 See also the SMP-HOWTO available at
95 <http://www.tldp.org/docs.html#howto>.
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96
97 Even if you don't know what to do here, say Y.
98
99config NR_CPUS
100 int "Maximum number of CPUs (2-64)"
101 range 2 64
102 depends on SMP
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103 default "32" if !64BIT
104 default "64" if 64BIT
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105 help
106 This allows you to specify the maximum number of CPUs which this
107 kernel will support. The maximum supported value is 64 and the
108 minimum value which makes sense is 2.
109
110 This is purely to save memory - each supported CPU adds
111 approximately sixteen kilobytes to the kernel image.
112
113config HOTPLUG_CPU
114 bool "Support for hot-pluggable CPUs"
115 depends on SMP
116 select HOTPLUG
117 default n
118 help
119 Say Y here to be able to turn CPUs off and on. CPUs
120 can be controlled through /sys/devices/system/cpu/cpu#.
121 Say N if you want to disable CPU hotplug.
122
123config MATHEMU
124 bool "IEEE FPU emulation"
125 depends on MARCH_G5
126 help
127 This option is required for IEEE compliant floating point arithmetic
128 on older S/390 machines. Say Y unless you know your machine doesn't
129 need this.
130
347a8dc3 131config COMPAT
1da177e4 132 bool "Kernel support for 31 bit emulation"
347a8dc3 133 depends on 64BIT
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134 help
135 Select this option if you want to enable your system kernel to
136 handle system-calls from ELF binaries for 31 bit ESA. This option
137 (and some other stuff like libraries and such) is needed for
138 executing 31 bit applications. It is safe to say "Y".
139
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140config SYSVIPC_COMPAT
141 bool
142 depends on COMPAT && SYSVIPC
143 default y
144
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145config AUDIT_ARCH
146 bool
147 default y
148
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149config S390_SWITCH_AMODE
150 bool "Switch kernel/user addressing modes"
151 help
152 This option allows to switch the addressing modes of kernel and user
153 space. The kernel parameter switch_amode=on will enable this feature,
154 default is disabled. Enabling this (via kernel parameter) on machines
155 earlier than IBM System z9-109 EC/BC will reduce system performance.
156
157 Note that this option will also be selected by selecting the execute
158 protection option below. Enabling the execute protection via the
159 noexec kernel parameter will also switch the addressing modes,
160 independent of the switch_amode kernel parameter.
161
162
163config S390_EXEC_PROTECT
164 bool "Data execute protection"
165 select S390_SWITCH_AMODE
166 help
167 This option allows to enable a buffer overflow protection for user
168 space programs and it also selects the addressing mode option above.
169 The kernel parameter noexec=on will enable this feature and also
170 switch the addressing modes, default is disabled. Enabling this (via
171 kernel parameter) on machines earlier than IBM System z9-109 EC/BC
172 will reduce system performance.
173
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174comment "Code generation options"
175
176choice
177 prompt "Processor type"
178 default MARCH_G5
179
180config MARCH_G5
181 bool "S/390 model G5 and G6"
347a8dc3 182 depends on !64BIT
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183 help
184 Select this to build a 31 bit kernel that works
185 on all S/390 and zSeries machines.
186
187config MARCH_Z900
188 bool "IBM eServer zSeries model z800 and z900"
189 help
190 Select this to optimize for zSeries machines. This
191 will enable some optimizations that are not available
192 on older 31 bit only CPUs.
193
194config MARCH_Z990
195 bool "IBM eServer zSeries model z890 and z990"
196 help
197 Select this enable optimizations for model z890/z990.
198 This will be slightly faster but does not work on
199 older machines such as the z900.
200
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201config MARCH_Z9_109
202 bool "IBM System z9"
203 help
204 Select this to enable optimizations for IBM System z9-109, IBM
205 System z9 Enterprise Class (z9 EC), and IBM System z9 Business
206 Class (z9 BC). The kernel will be slightly faster but will not
207 work on older machines such as the z990, z890, z900, and z800.
208
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209endchoice
210
211config PACK_STACK
212 bool "Pack kernel stack"
213 help
214 This option enables the compiler option -mkernel-backchain if it
215 is available. If the option is available the compiler supports
216 the new stack layout which dramatically reduces the minimum stack
217 frame size. With an old compiler a non-leaf function needs a
218 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
219 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
220 and 24 byte on 64 bit.
221
222 Say Y if you are unsure.
223
224config SMALL_STACK
225 bool "Use 4kb/8kb for kernel stack instead of 8kb/16kb"
74f8f557 226 depends on PACK_STACK && !LOCKDEP
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227 help
228 If you say Y here and the compiler supports the -mkernel-backchain
229 option the kernel will use a smaller kernel stack size. For 31 bit
230 the reduced size is 4kb instead of 8kb and for 64 bit it is 8kb
231 instead of 16kb. This allows to run more thread on a system and
232 reduces the pressure on the memory management for higher order
233 page allocations.
234
235 Say N if you are unsure.
236
237
238config CHECK_STACK
239 bool "Detect kernel stack overflow"
240 help
241 This option enables the compiler option -mstack-guard and
242 -mstack-size if they are available. If the compiler supports them
243 it will emit additional code to each function prolog to trigger
244 an illegal operation if the kernel stack is about to overflow.
245
246 Say N if you are unsure.
247
248config STACK_GUARD
249 int "Size of the guard area (128-1024)"
250 range 128 1024
251 depends on CHECK_STACK
252 default "256"
253 help
254 This allows you to specify the size of the guard area at the lower
255 end of the kernel stack. If the kernel stack points into the guard
256 area on function entry an illegal operation is triggered. The size
257 needs to be a power of 2. Please keep in mind that the size of an
258 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
259 The minimum size for the stack guard should be 256 for 31 bit and
260 512 for 64 bit.
261
262config WARN_STACK
263 bool "Emit compiler warnings for function with broken stack usage"
264 help
265 This option enables the compiler options -mwarn-framesize and
266 -mwarn-dynamicstack. If the compiler supports these options it
267 will generate warnings for function which either use alloca or
268 create a stack frame bigger then CONFIG_WARN_STACK_SIZE.
269
270 Say N if you are unsure.
271
272config WARN_STACK_SIZE
273 int "Maximum frame size considered safe (128-2048)"
274 range 128 2048
275 depends on WARN_STACK
276 default "256"
277 help
278 This allows you to specify the maximum frame size a function may
279 have without the compiler complaining about it.
280
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281config ARCH_POPULATES_NODE_MAP
282 def_bool y
283
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284comment "Kernel preemption"
285
286source "kernel/Kconfig.preempt"
287
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288source "mm/Kconfig"
289
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290comment "I/O subsystem configuration"
291
292config MACHCHK_WARNING
293 bool "Process warning machine checks"
294 help
295 Select this option if you want the machine check handler on IBM S/390 or
296 zSeries to process warning machine checks (e.g. on power failures).
297 If unsure, say "Y".
298
299config QDIO
300 tristate "QDIO support"
301 ---help---
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302 This driver provides the Queued Direct I/O base support for
303 IBM mainframes.
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304
305 For details please refer to the documentation provided by IBM at
306 <http://www10.software.ibm.com/developerworks/opensource/linux390>
307
308 To compile this driver as a module, choose M here: the
309 module will be called qdio.
310
311 If unsure, say Y.
312
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313config QDIO_DEBUG
314 bool "Extended debugging information"
315 depends on QDIO
316 help
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317 Say Y here to get extended debugging output in
318 /sys/kernel/debug/s390dbf/qdio...
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319 Warning: this option reduces the performance of the QDIO module.
320
321 If unsure, say N.
322
323comment "Misc"
324
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325config IPL
326 bool "Builtin IPL record support"
327 help
328 If you want to use the produced kernel to IPL directly from a
329 device, you have to merge a bootsector specific to the device
330 into the first bytes of the kernel. You will have to select the
331 IPL device.
332
333choice
334 prompt "IPL method generated into head.S"
335 depends on IPL
336 default IPL_TAPE
337 help
338 Select "tape" if you want to IPL the image from a Tape.
339
340 Select "vm_reader" if you are running under VM/ESA and want
341 to IPL the image from the emulated card reader.
342
343config IPL_TAPE
344 bool "tape"
345
346config IPL_VM
347 bool "vm_reader"
348
349endchoice
350
351source "fs/Kconfig.binfmt"
352
353config PROCESS_DEBUG
354 bool "Show crashed user process info"
355 help
356 Say Y to print all process fault locations to the console. This is
357 a debugging option; you probably do not want to set it unless you
358 are an S390 port maintainer.
359
360config PFAULT
361 bool "Pseudo page fault support"
362 help
363 Select this option, if you want to use PFAULT pseudo page fault
364 handling under VM. If running native or in LPAR, this option
365 has no effect. If your VM does not support PFAULT, PAGEEX
366 pseudo page fault handling will be used.
367 Note that VM 4.2 supports PFAULT but has a bug in its
368 implementation that causes some problems.
369 Everybody who wants to run Linux under VM != VM4.2 should select
370 this option.
371
372config SHARED_KERNEL
373 bool "VM shared kernel support"
374 help
375 Select this option, if you want to share the text segment of the
376 Linux kernel between different VM guests. This reduces memory
377 usage with lots of guests but greatly increases kernel size.
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378 Also if a kernel was IPL'ed from a shared segment the kexec system
379 call will not work.
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380 You should only select this option if you know what you are
381 doing and want to exploit this feature.
382
383config CMM
384 tristate "Cooperative memory management"
385 help
386 Select this option, if you want to enable the kernel interface
387 to reduce the memory size of the system. This is accomplished
388 by allocating pages of memory and put them "on hold". This only
389 makes sense for a system running under VM where the unused pages
390 will be reused by VM for other guest systems. The interface
391 allows an external monitor to balance memory of many systems.
392 Everybody who wants to run Linux under VM should select this
393 option.
394
395config CMM_PROC
396 bool "/proc interface to cooperative memory management"
397 depends on CMM
398 help
399 Select this option to enable the /proc interface to the
400 cooperative memory management.
401
402config CMM_IUCV
403 bool "IUCV special message interface to cooperative memory management"
404 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
405 help
406 Select this option to enable the special message interface to
407 the cooperative memory management.
408
409config VIRT_TIMER
410 bool "Virtual CPU timer support"
411 help
412 This provides a kernel interface for virtual CPU timers.
413 Default is disabled.
414
415config VIRT_CPU_ACCOUNTING
416 bool "Base user process accounting on virtual cpu timer"
417 depends on VIRT_TIMER
418 help
419 Select this option to use CPU timer deltas to do user
420 process accounting.
421
422config APPLDATA_BASE
423 bool "Linux - VM Monitor Stream, base infrastructure"
424 depends on PROC_FS && VIRT_TIMER=y
425 help
426 This provides a kernel interface for creating and updating z/VM APPLDATA
427 monitor records. The monitor records are updated at certain time
428 intervals, once the timer is started.
429 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
430 i.e. enables or disables monitoring on the Linux side.
431 A custom interval value (in seconds) can be written to
432 /proc/appldata/interval.
433
434 Defaults are 60 seconds interval and timer off.
435 The /proc entries can also be read from, showing the current settings.
436
437config APPLDATA_MEM
438 tristate "Monitor memory management statistics"
62fb2ba3 439 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
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440 help
441 This provides memory management related data to the Linux - VM Monitor
442 Stream, like paging/swapping rate, memory utilisation, etc.
443 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
444 APPLDATA monitor record, i.e. enables or disables monitoring this record
445 on the z/VM side.
446
447 Default is disabled.
448 The /proc entry can also be read from, showing the current settings.
449
450 This can also be compiled as a module, which will be called
451 appldata_mem.o.
452
453config APPLDATA_OS
454 tristate "Monitor OS statistics"
455 depends on APPLDATA_BASE
456 help
457 This provides OS related data to the Linux - VM Monitor Stream, like
458 CPU utilisation, etc.
459 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
460 APPLDATA monitor record, i.e. enables or disables monitoring this record
461 on the z/VM side.
462
463 Default is disabled.
464 This can also be compiled as a module, which will be called
465 appldata_os.o.
466
467config APPLDATA_NET_SUM
468 tristate "Monitor overall network statistics"
469 depends on APPLDATA_BASE
470 help
471 This provides network related data to the Linux - VM Monitor Stream,
472 currently there is only a total sum of network I/O statistics, no
473 per-interface data.
474 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
475 APPLDATA monitor record, i.e. enables or disables monitoring this record
476 on the z/VM side.
477
478 Default is disabled.
479 This can also be compiled as a module, which will be called
480 appldata_net_sum.o.
481
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482source kernel/Kconfig.hz
483
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484config NO_IDLE_HZ
485 bool "No HZ timer ticks in idle"
486 help
487 Switches the regular HZ timer off when the system is going idle.
488 This helps z/VM to detect that the Linux system is idle. VM can
489 then "swap-out" this guest which reduces memory usage. It also
490 reduces the overhead of idle systems.
491
492 The HZ timer can be switched on/off via /proc/sys/kernel/hz_timer.
493 hz_timer=0 means HZ timer is disabled. hz_timer=1 means HZ
494 timer is active.
495
496config NO_IDLE_HZ_INIT
497 bool "HZ timer in idle off by default"
498 depends on NO_IDLE_HZ
499 help
500 The HZ timer is switched off in idle by default. That means the
501 HZ timer is already disabled at boot time.
502
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503config S390_HYPFS_FS
504 bool "s390 hypervisor file system support"
505 select SYS_HYPERVISOR
506 default y
507 help
508 This is a virtual file system intended to provide accounting
509 information in an s390 hypervisor environment.
510
cf13f0ea 511config KEXEC
07d43ce6 512 bool "kexec system call"
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513 help
514 kexec is a system call that implements the ability to shutdown your
515 current kernel, and to start another kernel. It is like a reboot
516 but is independent of hardware/microcode support.
517
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518config ZFCPDUMP
519 tristate "zfcpdump support"
520 select SMP
521 default n
522 help
523 Select this option if you want to build an zfcpdump enabled kernel.
e403149c 524 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
411ed322 525
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526endmenu
527
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528source "net/Kconfig"
529
1da177e4 530config PCMCIA
61d48c2c 531 def_bool n
1da177e4 532
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533config CCW
534 def_bool y
1da177e4 535
61d48c2c 536source "drivers/Kconfig"
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537
538source "fs/Kconfig"
539
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540source "arch/s390/Kconfig.debug"
541
542source "security/Kconfig"
543
544source "crypto/Kconfig"
545
546source "lib/Kconfig"