xref: /openbmc/linux/arch/s390/Kconfig (revision 367b8112)
1#
2# For a description of the syntax of this configuration file,
3# see Documentation/kbuild/kconfig-language.txt.
4#
5
6config SCHED_MC
7	def_bool y
8	depends on SMP
9
10config MMU
11	def_bool y
12
13config ZONE_DMA
14	def_bool y
15	depends on 64BIT
16
17config LOCKDEP_SUPPORT
18	def_bool y
19
20config STACKTRACE_SUPPORT
21	def_bool y
22
23config HAVE_LATENCYTOP_SUPPORT
24	def_bool y
25
26config RWSEM_GENERIC_SPINLOCK
27	bool
28
29config RWSEM_XCHGADD_ALGORITHM
30	def_bool y
31
32config ARCH_HAS_ILOG2_U32
33	bool
34	default n
35
36config ARCH_HAS_ILOG2_U64
37	bool
38	default n
39
40config GENERIC_HWEIGHT
41	def_bool y
42
43config GENERIC_TIME
44	def_bool y
45
46config GENERIC_CLOCKEVENTS
47	def_bool y
48
49config GENERIC_BUG
50	bool
51	depends on BUG
52	default y
53
54config NO_IOMEM
55	def_bool y
56
57config NO_DMA
58	def_bool y
59
60config GENERIC_LOCKBREAK
61	bool
62	default y
63	depends on SMP && PREEMPT
64
65config PGSTE
66	bool
67	default y if KVM
68
69mainmenu "Linux Kernel Configuration"
70
71config S390
72	def_bool y
73	select HAVE_OPROFILE
74	select HAVE_KPROBES
75	select HAVE_KRETPROBES
76	select HAVE_KVM if 64BIT
77	select HAVE_ARCH_TRACEHOOK
78
79source "init/Kconfig"
80
81source "kernel/Kconfig.freezer"
82
83menu "Base setup"
84
85comment "Processor type and features"
86
87source "kernel/time/Kconfig"
88
89config 64BIT
90	bool "64 bit kernel"
91	help
92	  Select this option if you have a 64 bit IBM zSeries machine
93	  and want to use the 64 bit addressing mode.
94
95config 32BIT
96	bool
97	default y if !64BIT
98
99config SMP
100	bool "Symmetric multi-processing support"
101	---help---
102	  This enables support for systems with more than one CPU. If you have
103	  a system with only one CPU, like most personal computers, say N. If
104	  you have a system with more than one CPU, say Y.
105
106	  If you say N here, the kernel will run on single and multiprocessor
107	  machines, but will use only one CPU of a multiprocessor machine. If
108	  you say Y here, the kernel will run on many, but not all,
109	  singleprocessor machines. On a singleprocessor machine, the kernel
110	  will run faster if you say N here.
111
112	  See also the SMP-HOWTO available at
113	  <http://www.tldp.org/docs.html#howto>.
114
115	  Even if you don't know what to do here, say Y.
116
117config NR_CPUS
118	int "Maximum number of CPUs (2-64)"
119	range 2 64
120	depends on SMP
121	default "32" if !64BIT
122	default "64" if 64BIT
123	help
124	  This allows you to specify the maximum number of CPUs which this
125	  kernel will support.  The maximum supported value is 64 and the
126	  minimum value which makes sense is 2.
127
128	  This is purely to save memory - each supported CPU adds
129	  approximately sixteen kilobytes to the kernel image.
130
131config HOTPLUG_CPU
132	bool "Support for hot-pluggable CPUs"
133	depends on SMP
134	select HOTPLUG
135	default n
136	help
137	  Say Y here to be able to turn CPUs off and on. CPUs
138	  can be controlled through /sys/devices/system/cpu/cpu#.
139	  Say N if you want to disable CPU hotplug.
140
141config MATHEMU
142	bool "IEEE FPU emulation"
143	depends on MARCH_G5
144	help
145	  This option is required for IEEE compliant floating point arithmetic
146	  on older S/390 machines. Say Y unless you know your machine doesn't
147	  need this.
148
149config COMPAT
150	bool "Kernel support for 31 bit emulation"
151	depends on 64BIT
152	select COMPAT_BINFMT_ELF
153	help
154	  Select this option if you want to enable your system kernel to
155	  handle system-calls from ELF binaries for 31 bit ESA.  This option
156	  (and some other stuff like libraries and such) is needed for
157	  executing 31 bit applications.  It is safe to say "Y".
158
159config SYSVIPC_COMPAT
160	bool
161	depends on COMPAT && SYSVIPC
162	default y
163
164config AUDIT_ARCH
165	bool
166	default y
167
168config S390_SWITCH_AMODE
169	bool "Switch kernel/user addressing modes"
170	help
171	  This option allows to switch the addressing modes of kernel and user
172	  space. The kernel parameter switch_amode=on will enable this feature,
173	  default is disabled. Enabling this (via kernel parameter) on machines
174	  earlier than IBM System z9-109 EC/BC will reduce system performance.
175
176	  Note that this option will also be selected by selecting the execute
177	  protection option below. Enabling the execute protection via the
178	  noexec kernel parameter will also switch the addressing modes,
179	  independent of the switch_amode kernel parameter.
180
181
182config S390_EXEC_PROTECT
183	bool "Data execute protection"
184	select S390_SWITCH_AMODE
185	help
186	  This option allows to enable a buffer overflow protection for user
187	  space programs and it also selects the addressing mode option above.
188	  The kernel parameter noexec=on will enable this feature and also
189	  switch the addressing modes, default is disabled. Enabling this (via
190	  kernel parameter) on machines earlier than IBM System z9-109 EC/BC
191	  will reduce system performance.
192
193comment "Code generation options"
194
195choice
196	prompt "Processor type"
197	default MARCH_G5
198
199config MARCH_G5
200	bool "S/390 model G5 and G6"
201	depends on !64BIT
202	help
203	  Select this to build a 31 bit kernel that works
204	  on all S/390 and zSeries machines.
205
206config MARCH_Z900
207	bool "IBM eServer zSeries model z800 and z900"
208	help
209	  Select this to optimize for zSeries machines. This
210	  will enable some optimizations that are not available
211	  on older 31 bit only CPUs.
212
213config MARCH_Z990
214	bool "IBM eServer zSeries model z890 and z990"
215	help
216	  Select this enable optimizations for model z890/z990.
217	  This will be slightly faster but does not work on
218	  older machines such as the z900.
219
220config MARCH_Z9_109
221	bool "IBM System z9"
222	help
223	  Select this to enable optimizations for IBM System z9-109, IBM
224	  System z9 Enterprise Class (z9 EC), and IBM System z9 Business
225	  Class (z9 BC). The kernel will be slightly faster but will not
226	  work on older machines such as the z990, z890, z900, and z800.
227
228endchoice
229
230config PACK_STACK
231	bool "Pack kernel stack"
232	help
233	  This option enables the compiler option -mkernel-backchain if it
234	  is available. If the option is available the compiler supports
235	  the new stack layout which dramatically reduces the minimum stack
236	  frame size. With an old compiler a non-leaf function needs a
237	  minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
238	  -mkernel-backchain the minimum size drops to 16 byte on 31 bit
239	  and 24 byte on 64 bit.
240
241	  Say Y if you are unsure.
242
243config SMALL_STACK
244	bool "Use 8kb for kernel stack instead of 16kb"
245	depends on PACK_STACK && 64BIT && !LOCKDEP
246	help
247	  If you say Y here and the compiler supports the -mkernel-backchain
248	  option the kernel will use a smaller kernel stack size. The reduced
249	  size is 8kb instead of 16kb. This allows to run more threads on a
250	  system and reduces the pressure on the memory management for higher
251	  order page allocations.
252
253	  Say N if you are unsure.
254
255config CHECK_STACK
256	bool "Detect kernel stack overflow"
257	help
258	  This option enables the compiler option -mstack-guard and
259	  -mstack-size if they are available. If the compiler supports them
260	  it will emit additional code to each function prolog to trigger
261	  an illegal operation if the kernel stack is about to overflow.
262
263	  Say N if you are unsure.
264
265config STACK_GUARD
266	int "Size of the guard area (128-1024)"
267	range 128 1024
268	depends on CHECK_STACK
269	default "256"
270	help
271	  This allows you to specify the size of the guard area at the lower
272	  end of the kernel stack. If the kernel stack points into the guard
273	  area on function entry an illegal operation is triggered. The size
274	  needs to be a power of 2. Please keep in mind that the size of an
275	  interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
276	  The minimum size for the stack guard should be 256 for 31 bit and
277	  512 for 64 bit.
278
279config WARN_STACK
280	bool "Emit compiler warnings for function with broken stack usage"
281	help
282	  This option enables the compiler options -mwarn-framesize and
283	  -mwarn-dynamicstack. If the compiler supports these options it
284	  will generate warnings for function which either use alloca or
285	  create a stack frame bigger then CONFIG_WARN_STACK_SIZE.
286
287	  Say N if you are unsure.
288
289config WARN_STACK_SIZE
290	int "Maximum frame size considered safe (128-2048)"
291	range 128 2048
292	depends on WARN_STACK
293	default "2048"
294	help
295	  This allows you to specify the maximum frame size a function may
296	  have without the compiler complaining about it.
297
298config ARCH_POPULATES_NODE_MAP
299	def_bool y
300
301comment "Kernel preemption"
302
303source "kernel/Kconfig.preempt"
304
305config ARCH_SPARSEMEM_ENABLE
306	def_bool y
307	select SPARSEMEM_VMEMMAP_ENABLE
308	select SPARSEMEM_VMEMMAP
309	select SPARSEMEM_STATIC if !64BIT
310
311config ARCH_SPARSEMEM_DEFAULT
312	def_bool y
313
314config ARCH_SELECT_MEMORY_MODEL
315       def_bool y
316
317config ARCH_ENABLE_MEMORY_HOTPLUG
318	def_bool y
319	depends on SPARSEMEM
320
321config ARCH_ENABLE_MEMORY_HOTREMOVE
322	def_bool y
323
324source "mm/Kconfig"
325
326comment "I/O subsystem configuration"
327
328config MACHCHK_WARNING
329	bool "Process warning machine checks"
330	help
331	  Select this option if you want the machine check handler on IBM S/390 or
332	  zSeries to process warning machine checks (e.g. on power failures).
333	  If unsure, say "Y".
334
335config QDIO
336	tristate "QDIO support"
337	---help---
338	  This driver provides the Queued Direct I/O base support for
339	  IBM System z.
340
341	  To compile this driver as a module, choose M here: the
342	  module will be called qdio.
343
344	  If unsure, say Y.
345
346config QDIO_DEBUG
347	bool "Extended debugging information"
348	depends on QDIO
349	help
350	  Say Y here to get extended debugging output in
351	    /sys/kernel/debug/s390dbf/qdio...
352	  Warning: this option reduces the performance of the QDIO module.
353
354	  If unsure, say N.
355
356config CHSC_SCH
357	tristate "Support for CHSC subchannels"
358	help
359	  This driver allows usage of CHSC subchannels. A CHSC subchannel
360	  is usually present on LPAR only.
361	  The driver creates a device /dev/chsc, which may be used to
362	  obtain I/O configuration information about the machine and
363	  to issue asynchronous chsc commands (DANGEROUS).
364	  You will usually only want to use this interface on a special
365	  LPAR designated for system management.
366
367	  To compile this driver as a module, choose M here: the
368	  module will be called chsc_sch.
369
370	  If unsure, say N.
371
372comment "Misc"
373
374config IPL
375	bool "Builtin IPL record support"
376	help
377	  If you want to use the produced kernel to IPL directly from a
378	  device, you have to merge a bootsector specific to the device
379	  into the first bytes of the kernel. You will have to select the
380	  IPL device.
381
382choice
383	prompt "IPL method generated into head.S"
384	depends on IPL
385	default IPL_VM
386	help
387	  Select "tape" if you want to IPL the image from a Tape.
388
389	  Select "vm_reader" if you are running under VM/ESA and want
390	  to IPL the image from the emulated card reader.
391
392config IPL_TAPE
393	bool "tape"
394
395config IPL_VM
396	bool "vm_reader"
397
398endchoice
399
400source "fs/Kconfig.binfmt"
401
402config FORCE_MAX_ZONEORDER
403	int
404	default "9"
405
406config PROCESS_DEBUG
407	bool "Show crashed user process info"
408	help
409	  Say Y to print all process fault locations to the console.  This is
410	  a debugging option; you probably do not want to set it unless you
411	  are an S390 port maintainer.
412
413config PFAULT
414	bool "Pseudo page fault support"
415	help
416	  Select this option, if you want to use PFAULT pseudo page fault
417	  handling under VM. If running native or in LPAR, this option
418	  has no effect. If your VM does not support PFAULT, PAGEEX
419	  pseudo page fault handling will be used.
420	  Note that VM 4.2 supports PFAULT but has a bug in its
421	  implementation that causes some problems.
422	  Everybody who wants to run Linux under VM != VM4.2 should select
423	  this option.
424
425config SHARED_KERNEL
426	bool "VM shared kernel support"
427	help
428	  Select this option, if you want to share the text segment of the
429	  Linux kernel between different VM guests. This reduces memory
430	  usage with lots of guests but greatly increases kernel size.
431	  Also if a kernel was IPL'ed from a shared segment the kexec system
432	  call will not work.
433	  You should only select this option if you know what you are
434	  doing and want to exploit this feature.
435
436config CMM
437	tristate "Cooperative memory management"
438	help
439	  Select this option, if you want to enable the kernel interface
440	  to reduce the memory size of the system. This is accomplished
441	  by allocating pages of memory and put them "on hold". This only
442	  makes sense for a system running under VM where the unused pages
443	  will be reused by VM for other guest systems. The interface
444	  allows an external monitor to balance memory of many systems.
445	  Everybody who wants to run Linux under VM should select this
446	  option.
447
448config CMM_PROC
449	bool "/proc interface to cooperative memory management"
450	depends on CMM
451	help
452	  Select this option to enable the /proc interface to the
453	  cooperative memory management.
454
455config CMM_IUCV
456	bool "IUCV special message interface to cooperative memory management"
457	depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
458	help
459	  Select this option to enable the special message interface to
460	  the cooperative memory management.
461
462config PAGE_STATES
463	bool "Unused page notification"
464	help
465	  This enables the notification of unused pages to the
466	  hypervisor. The ESSA instruction is used to do the states
467	  changes between a page that has content and the unused state.
468
469config VIRT_TIMER
470	bool "Virtual CPU timer support"
471	help
472	  This provides a kernel interface for virtual CPU timers.
473	  Default is disabled.
474
475config VIRT_CPU_ACCOUNTING
476	bool "Base user process accounting on virtual cpu timer"
477	depends on VIRT_TIMER
478	help
479	  Select this option to use CPU timer deltas to do user
480	  process accounting.
481
482config APPLDATA_BASE
483	bool "Linux - VM Monitor Stream, base infrastructure"
484	depends on PROC_FS && VIRT_TIMER=y
485	help
486	  This provides a kernel interface for creating and updating z/VM APPLDATA
487	  monitor records. The monitor records are updated at certain time
488	  intervals, once the timer is started.
489	  Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
490	  i.e. enables or disables monitoring on the Linux side.
491	  A custom interval value (in seconds) can be written to
492	  /proc/appldata/interval.
493
494	  Defaults are 60 seconds interval and timer off.
495	  The /proc entries can also be read from, showing the current settings.
496
497config APPLDATA_MEM
498	tristate "Monitor memory management statistics"
499	depends on APPLDATA_BASE && VM_EVENT_COUNTERS
500	help
501	  This provides memory management related data to the Linux - VM Monitor
502	  Stream, like paging/swapping rate, memory utilisation, etc.
503	  Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
504	  APPLDATA monitor record, i.e. enables or disables monitoring this record
505	  on the z/VM side.
506
507	  Default is disabled.
508	  The /proc entry can also be read from, showing the current settings.
509
510	  This can also be compiled as a module, which will be called
511	  appldata_mem.o.
512
513config APPLDATA_OS
514	tristate "Monitor OS statistics"
515	depends on APPLDATA_BASE
516	help
517	  This provides OS related data to the Linux - VM Monitor Stream, like
518	  CPU utilisation, etc.
519	  Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
520	  APPLDATA monitor record, i.e. enables or disables monitoring this record
521	  on the z/VM side.
522
523	  Default is disabled.
524	  This can also be compiled as a module, which will be called
525	  appldata_os.o.
526
527config APPLDATA_NET_SUM
528	tristate "Monitor overall network statistics"
529	depends on APPLDATA_BASE
530	help
531	  This provides network related data to the Linux - VM Monitor Stream,
532	  currently there is only a total sum of network I/O statistics, no
533	  per-interface data.
534	  Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
535	  APPLDATA monitor record, i.e. enables or disables monitoring this record
536	  on the z/VM side.
537
538	  Default is disabled.
539	  This can also be compiled as a module, which will be called
540	  appldata_net_sum.o.
541
542source kernel/Kconfig.hz
543
544config S390_HYPFS_FS
545	bool "s390 hypervisor file system support"
546	select SYS_HYPERVISOR
547	default y
548	help
549	  This is a virtual file system intended to provide accounting
550	  information in an s390 hypervisor environment.
551
552config KEXEC
553	bool "kexec system call"
554	help
555	  kexec is a system call that implements the ability to shutdown your
556	  current kernel, and to start another kernel.  It is like a reboot
557	  but is independent of hardware/microcode support.
558
559config ZFCPDUMP
560	tristate "zfcpdump support"
561	select SMP
562	default n
563	help
564	  Select this option if you want to build an zfcpdump enabled kernel.
565	  Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
566
567config S390_GUEST
568bool "s390 guest support for KVM (EXPERIMENTAL)"
569	depends on 64BIT && EXPERIMENTAL
570	select VIRTIO
571	select VIRTIO_RING
572	select VIRTIO_CONSOLE
573	help
574	  Select this option if you want to run the kernel as a guest under
575	  the KVM hypervisor. This will add detection for KVM as well  as a
576	  virtio transport. If KVM is detected, the virtio console will be
577	  the default console.
578endmenu
579
580source "net/Kconfig"
581
582config PCMCIA
583	def_bool n
584
585config CCW
586	def_bool y
587
588source "drivers/Kconfig"
589
590source "fs/Kconfig"
591
592source "arch/s390/Kconfig.debug"
593
594source "security/Kconfig"
595
596source "crypto/Kconfig"
597
598source "lib/Kconfig"
599
600source "arch/s390/kvm/Kconfig"
601