xref: /openbmc/linux/arch/s390/Kconfig (revision 5d331b7f)
1# SPDX-License-Identifier: GPL-2.0
2config MMU
3	def_bool y
4
5config ZONE_DMA
6	def_bool y
7
8config CPU_BIG_ENDIAN
9	def_bool y
10
11config LOCKDEP_SUPPORT
12	def_bool y
13
14config STACKTRACE_SUPPORT
15	def_bool y
16
17config RWSEM_GENERIC_SPINLOCK
18	bool
19
20config RWSEM_XCHGADD_ALGORITHM
21	def_bool y
22
23config ARCH_HAS_ILOG2_U32
24	def_bool n
25
26config ARCH_HAS_ILOG2_U64
27	def_bool n
28
29config GENERIC_HWEIGHT
30	def_bool y
31
32config GENERIC_BUG
33	def_bool y if BUG
34
35config GENERIC_BUG_RELATIVE_POINTERS
36	def_bool y
37
38config GENERIC_LOCKBREAK
39	def_bool y if SMP && PREEMPT
40
41config PGSTE
42	def_bool y if KVM
43
44config ARCH_SUPPORTS_DEBUG_PAGEALLOC
45	def_bool y
46
47config AUDIT_ARCH
48	def_bool y
49
50config NO_IOPORT_MAP
51	def_bool y
52
53config PCI_QUIRKS
54	def_bool n
55
56config ARCH_SUPPORTS_UPROBES
57	def_bool y
58
59config KASAN_SHADOW_OFFSET
60	hex
61	depends on KASAN
62	default 0x18000000000000 if KASAN_S390_4_LEVEL_PAGING
63	default 0x30000000000
64
65config S390
66	def_bool y
67	select ARCH_BINFMT_ELF_STATE
68	select ARCH_HAS_DEVMEM_IS_ALLOWED
69	select ARCH_HAS_ELF_RANDOMIZE
70	select ARCH_HAS_FORTIFY_SOURCE
71	select ARCH_HAS_GCOV_PROFILE_ALL
72	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
73	select ARCH_HAS_KCOV
74	select ARCH_HAS_PTE_SPECIAL
75	select ARCH_HAS_SET_MEMORY
76	select ARCH_HAS_SG_CHAIN
77	select ARCH_HAS_STRICT_KERNEL_RWX
78	select ARCH_HAS_STRICT_MODULE_RWX
79	select ARCH_HAS_UBSAN_SANITIZE_ALL
80	select ARCH_HAVE_NMI_SAFE_CMPXCHG
81	select ARCH_INLINE_READ_LOCK
82	select ARCH_INLINE_READ_LOCK_BH
83	select ARCH_INLINE_READ_LOCK_IRQ
84	select ARCH_INLINE_READ_LOCK_IRQSAVE
85	select ARCH_INLINE_READ_TRYLOCK
86	select ARCH_INLINE_READ_UNLOCK
87	select ARCH_INLINE_READ_UNLOCK_BH
88	select ARCH_INLINE_READ_UNLOCK_IRQ
89	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
90	select ARCH_INLINE_SPIN_LOCK
91	select ARCH_INLINE_SPIN_LOCK_BH
92	select ARCH_INLINE_SPIN_LOCK_IRQ
93	select ARCH_INLINE_SPIN_LOCK_IRQSAVE
94	select ARCH_INLINE_SPIN_TRYLOCK
95	select ARCH_INLINE_SPIN_TRYLOCK_BH
96	select ARCH_INLINE_SPIN_UNLOCK
97	select ARCH_INLINE_SPIN_UNLOCK_BH
98	select ARCH_INLINE_SPIN_UNLOCK_IRQ
99	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
100	select ARCH_INLINE_WRITE_LOCK
101	select ARCH_INLINE_WRITE_LOCK_BH
102	select ARCH_INLINE_WRITE_LOCK_IRQ
103	select ARCH_INLINE_WRITE_LOCK_IRQSAVE
104	select ARCH_INLINE_WRITE_TRYLOCK
105	select ARCH_INLINE_WRITE_UNLOCK
106	select ARCH_INLINE_WRITE_UNLOCK_BH
107	select ARCH_INLINE_WRITE_UNLOCK_IRQ
108	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
109	select ARCH_SAVE_PAGE_KEYS if HIBERNATION
110	select ARCH_SUPPORTS_ATOMIC_RMW
111	select ARCH_SUPPORTS_NUMA_BALANCING
112	select ARCH_USE_BUILTIN_BSWAP
113	select ARCH_USE_CMPXCHG_LOCKREF
114	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
115	select ARCH_WANT_IPC_PARSE_VERSION
116	select BUILDTIME_EXTABLE_SORT
117	select CLONE_BACKWARDS2
118	select DYNAMIC_FTRACE if FUNCTION_TRACER
119	select GENERIC_CLOCKEVENTS
120	select GENERIC_CPU_AUTOPROBE
121	select GENERIC_CPU_DEVICES if !SMP
122	select GENERIC_CPU_VULNERABILITIES
123	select GENERIC_FIND_FIRST_BIT
124	select GENERIC_SMP_IDLE_THREAD
125	select GENERIC_TIME_VSYSCALL
126	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
127	select HAVE_ARCH_AUDITSYSCALL
128	select HAVE_ARCH_JUMP_LABEL
129	select HAVE_ARCH_JUMP_LABEL_RELATIVE
130	select HAVE_ARCH_KASAN
131	select CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES
132	select HAVE_ARCH_SECCOMP_FILTER
133	select HAVE_ARCH_SOFT_DIRTY
134	select HAVE_ARCH_TRACEHOOK
135	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
136	select HAVE_ARCH_VMAP_STACK
137	select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
138	select HAVE_CMPXCHG_DOUBLE
139	select HAVE_CMPXCHG_LOCAL
140	select HAVE_COPY_THREAD_TLS
141	select HAVE_DEBUG_KMEMLEAK
142	select HAVE_DMA_CONTIGUOUS
143	select DMA_DIRECT_OPS
144	select HAVE_DYNAMIC_FTRACE
145	select HAVE_DYNAMIC_FTRACE_WITH_REGS
146	select HAVE_EFFICIENT_UNALIGNED_ACCESS
147	select HAVE_FENTRY
148	select HAVE_FTRACE_MCOUNT_RECORD
149	select HAVE_FUNCTION_GRAPH_TRACER
150	select HAVE_FUNCTION_TRACER
151	select HAVE_FUTEX_CMPXCHG if FUTEX
152	select HAVE_GCC_PLUGINS
153	select HAVE_KERNEL_BZIP2
154	select HAVE_KERNEL_GZIP
155	select HAVE_KERNEL_LZ4
156	select HAVE_KERNEL_LZMA
157	select HAVE_KERNEL_LZO
158	select HAVE_KERNEL_UNCOMPRESSED
159	select HAVE_KERNEL_XZ
160	select HAVE_KPROBES
161	select HAVE_KRETPROBES
162	select HAVE_KVM
163	select HAVE_LIVEPATCH
164	select HAVE_PERF_REGS
165	select HAVE_PERF_USER_STACK_DUMP
166	select HAVE_MEMBLOCK_NODE_MAP
167	select HAVE_MEMBLOCK_PHYS_MAP
168	select HAVE_MOD_ARCH_SPECIFIC
169	select HAVE_NOP_MCOUNT
170	select HAVE_OPROFILE
171	select HAVE_PERF_EVENTS
172	select HAVE_REGS_AND_STACK_ACCESS_API
173	select HAVE_RSEQ
174	select HAVE_SYSCALL_TRACEPOINTS
175	select HAVE_VIRT_CPU_ACCOUNTING
176	select MODULES_USE_ELF_RELA
177	select OLD_SIGACTION
178	select OLD_SIGSUSPEND3
179	select SPARSE_IRQ
180	select SYSCTL_EXCEPTION_TRACE
181	select THREAD_INFO_IN_TASK
182	select TTY
183	select VIRT_CPU_ACCOUNTING
184	select ARCH_HAS_SCALED_CPUTIME
185	select VIRT_TO_BUS
186	select HAVE_NMI
187
188
189config SCHED_OMIT_FRAME_POINTER
190	def_bool y
191
192config PGTABLE_LEVELS
193	int
194	default 5
195
196source "kernel/livepatch/Kconfig"
197
198menu "Processor type and features"
199
200config HAVE_MARCH_Z900_FEATURES
201	def_bool n
202
203config HAVE_MARCH_Z990_FEATURES
204	def_bool n
205	select HAVE_MARCH_Z900_FEATURES
206
207config HAVE_MARCH_Z9_109_FEATURES
208	def_bool n
209	select HAVE_MARCH_Z990_FEATURES
210
211config HAVE_MARCH_Z10_FEATURES
212	def_bool n
213	select HAVE_MARCH_Z9_109_FEATURES
214
215config HAVE_MARCH_Z196_FEATURES
216	def_bool n
217	select HAVE_MARCH_Z10_FEATURES
218
219config HAVE_MARCH_ZEC12_FEATURES
220	def_bool n
221	select HAVE_MARCH_Z196_FEATURES
222
223config HAVE_MARCH_Z13_FEATURES
224	def_bool n
225	select HAVE_MARCH_ZEC12_FEATURES
226
227config HAVE_MARCH_Z14_FEATURES
228	def_bool n
229	select HAVE_MARCH_Z13_FEATURES
230
231choice
232	prompt "Processor type"
233	default MARCH_Z196
234
235config MARCH_Z900
236	bool "IBM zSeries model z800 and z900"
237	select HAVE_MARCH_Z900_FEATURES
238	help
239	  Select this to enable optimizations for model z800/z900 (2064 and
240	  2066 series). This will enable some optimizations that are not
241	  available on older ESA/390 (31 Bit) only CPUs.
242
243config MARCH_Z990
244	bool "IBM zSeries model z890 and z990"
245	select HAVE_MARCH_Z990_FEATURES
246	help
247	  Select this to enable optimizations for model z890/z990 (2084 and
248	  2086 series). The kernel will be slightly faster but will not work
249	  on older machines.
250
251config MARCH_Z9_109
252	bool "IBM System z9"
253	select HAVE_MARCH_Z9_109_FEATURES
254	help
255	  Select this to enable optimizations for IBM System z9 (2094 and
256	  2096 series). The kernel will be slightly faster but will not work
257	  on older machines.
258
259config MARCH_Z10
260	bool "IBM System z10"
261	select HAVE_MARCH_Z10_FEATURES
262	help
263	  Select this to enable optimizations for IBM System z10 (2097 and
264	  2098 series). The kernel will be slightly faster but will not work
265	  on older machines.
266
267config MARCH_Z196
268	bool "IBM zEnterprise 114 and 196"
269	select HAVE_MARCH_Z196_FEATURES
270	help
271	  Select this to enable optimizations for IBM zEnterprise 114 and 196
272	  (2818 and 2817 series). The kernel will be slightly faster but will
273	  not work on older machines.
274
275config MARCH_ZEC12
276	bool "IBM zBC12 and zEC12"
277	select HAVE_MARCH_ZEC12_FEATURES
278	help
279	  Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
280	  2827 series). The kernel will be slightly faster but will not work on
281	  older machines.
282
283config MARCH_Z13
284	bool "IBM z13s and z13"
285	select HAVE_MARCH_Z13_FEATURES
286	help
287	  Select this to enable optimizations for IBM z13s and z13 (2965 and
288	  2964 series). The kernel will be slightly faster but will not work on
289	  older machines.
290
291config MARCH_Z14
292	bool "IBM z14 ZR1 and z14"
293	select HAVE_MARCH_Z14_FEATURES
294	help
295	  Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
296	  and 3906 series). The kernel will be slightly faster but will not
297	  work on older machines.
298
299endchoice
300
301config MARCH_Z900_TUNE
302	def_bool TUNE_Z900 || MARCH_Z900 && TUNE_DEFAULT
303
304config MARCH_Z990_TUNE
305	def_bool TUNE_Z990 || MARCH_Z990 && TUNE_DEFAULT
306
307config MARCH_Z9_109_TUNE
308	def_bool TUNE_Z9_109 || MARCH_Z9_109 && TUNE_DEFAULT
309
310config MARCH_Z10_TUNE
311	def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
312
313config MARCH_Z196_TUNE
314	def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
315
316config MARCH_ZEC12_TUNE
317	def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
318
319config MARCH_Z13_TUNE
320	def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
321
322config MARCH_Z14_TUNE
323	def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
324
325choice
326	prompt "Tune code generation"
327	default TUNE_DEFAULT
328	help
329	  Cause the compiler to tune (-mtune) the generated code for a machine.
330	  This will make the code run faster on the selected machine but
331	  somewhat slower on other machines.
332	  This option only changes how the compiler emits instructions, not the
333	  selection of instructions itself, so the resulting kernel will run on
334	  all other machines.
335
336config TUNE_DEFAULT
337	bool "Default"
338	help
339	  Tune the generated code for the target processor for which the kernel
340	  will be compiled.
341
342config TUNE_Z900
343	bool "IBM zSeries model z800 and z900"
344
345config TUNE_Z990
346	bool "IBM zSeries model z890 and z990"
347
348config TUNE_Z9_109
349	bool "IBM System z9"
350
351config TUNE_Z10
352	bool "IBM System z10"
353
354config TUNE_Z196
355	bool "IBM zEnterprise 114 and 196"
356
357config TUNE_ZEC12
358	bool "IBM zBC12 and zEC12"
359
360config TUNE_Z13
361	bool "IBM z13"
362
363config TUNE_Z14
364	bool "IBM z14"
365
366endchoice
367
368config 64BIT
369	def_bool y
370
371config COMPAT
372	def_bool y
373	prompt "Kernel support for 31 bit emulation"
374	select COMPAT_BINFMT_ELF if BINFMT_ELF
375	select ARCH_WANT_OLD_COMPAT_IPC
376	select COMPAT_OLD_SIGACTION
377	depends on MULTIUSER
378	help
379	  Select this option if you want to enable your system kernel to
380	  handle system-calls from ELF binaries for 31 bit ESA.  This option
381	  (and some other stuff like libraries and such) is needed for
382	  executing 31 bit applications.  It is safe to say "Y".
383
384config SYSVIPC_COMPAT
385	def_bool y if COMPAT && SYSVIPC
386
387config SMP
388	def_bool y
389	prompt "Symmetric multi-processing support"
390	---help---
391	  This enables support for systems with more than one CPU. If you have
392	  a system with only one CPU, like most personal computers, say N. If
393	  you have a system with more than one CPU, say Y.
394
395	  If you say N here, the kernel will run on uni- and multiprocessor
396	  machines, but will use only one CPU of a multiprocessor machine. If
397	  you say Y here, the kernel will run on many, but not all,
398	  uniprocessor machines. On a uniprocessor machine, the kernel
399	  will run faster if you say N here.
400
401	  See also the SMP-HOWTO available at
402	  <http://www.tldp.org/docs.html#howto>.
403
404	  Even if you don't know what to do here, say Y.
405
406config NR_CPUS
407	int "Maximum number of CPUs (2-512)"
408	range 2 512
409	depends on SMP
410	default "64"
411	help
412	  This allows you to specify the maximum number of CPUs which this
413	  kernel will support. The maximum supported value is 512 and the
414	  minimum value which makes sense is 2.
415
416	  This is purely to save memory - each supported CPU adds
417	  approximately sixteen kilobytes to the kernel image.
418
419config HOTPLUG_CPU
420	def_bool y
421	prompt "Support for hot-pluggable CPUs"
422	depends on SMP
423	help
424	  Say Y here to be able to turn CPUs off and on. CPUs
425	  can be controlled through /sys/devices/system/cpu/cpu#.
426	  Say N if you want to disable CPU hotplug.
427
428# Some NUMA nodes have memory ranges that span
429# other nodes.	Even though a pfn is valid and
430# between a node's start and end pfns, it may not
431# reside on that node.	See memmap_init_zone()
432# for details. <- They meant memory holes!
433config NODES_SPAN_OTHER_NODES
434	def_bool NUMA
435
436config NUMA
437	bool "NUMA support"
438	depends on SMP && SCHED_TOPOLOGY
439	default n
440	help
441	  Enable NUMA support
442
443	  This option adds NUMA support to the kernel.
444
445	  An operation mode can be selected by appending
446	  numa=<method> to the kernel command line.
447
448	  The default behaviour is identical to appending numa=plain to
449	  the command line. This will create just one node with all
450	  available memory and all CPUs in it.
451
452config NODES_SHIFT
453	int "Maximum NUMA nodes (as a power of 2)"
454	range 1 10
455	depends on NUMA
456	default "4"
457	help
458	  Specify the maximum number of NUMA nodes available on the target
459	  system. Increases memory reserved to accommodate various tables.
460
461menu "Select NUMA modes"
462	depends on NUMA
463
464config NUMA_EMU
465	bool "NUMA emulation"
466	default y
467	help
468	  Numa emulation mode will split the available system memory into
469	  equal chunks which then are distributed over the configured number
470	  of nodes in a round-robin manner.
471
472	  The number of fake nodes is limited by the number of available memory
473	  chunks (i.e. memory size / fake size) and the number of supported
474	  nodes in the kernel.
475
476	  The CPUs are assigned to the nodes in a way that partially respects
477	  the original machine topology (if supported by the machine).
478	  Fair distribution of the CPUs is not guaranteed.
479
480config EMU_SIZE
481	hex "NUMA emulation memory chunk size"
482	default 0x10000000
483	range 0x400000 0x100000000
484	depends on NUMA_EMU
485	help
486	  Select the default size by which the memory is chopped and then
487	  assigned to emulated NUMA nodes.
488
489	  This can be overridden by specifying
490
491	  emu_size=<n>
492
493	  on the kernel command line where also suffixes K, M, G, and T are
494	  supported.
495
496endmenu
497
498config SCHED_SMT
499	def_bool n
500
501config SCHED_MC
502	def_bool n
503
504config SCHED_BOOK
505	def_bool n
506
507config SCHED_DRAWER
508	def_bool n
509
510config SCHED_TOPOLOGY
511	def_bool y
512	prompt "Topology scheduler support"
513	depends on SMP
514	select SCHED_SMT
515	select SCHED_MC
516	select SCHED_BOOK
517	select SCHED_DRAWER
518	help
519	  Topology scheduler support improves the CPU scheduler's decision
520	  making when dealing with machines that have multi-threading,
521	  multiple cores or multiple books.
522
523source kernel/Kconfig.hz
524
525config KEXEC
526	def_bool y
527	select KEXEC_CORE
528
529config KEXEC_FILE
530	bool "kexec file based system call"
531	select KEXEC_CORE
532	select BUILD_BIN2C
533	depends on CRYPTO
534	depends on CRYPTO_SHA256
535	depends on CRYPTO_SHA256_S390
536	help
537	  Enable the kexec file based system call. In contrast to the normal
538	  kexec system call this system call takes file descriptors for the
539	  kernel and initramfs as arguments.
540
541config ARCH_HAS_KEXEC_PURGATORY
542	def_bool y
543	depends on KEXEC_FILE
544
545config ARCH_RANDOM
546	def_bool y
547	prompt "s390 architectural random number generation API"
548	help
549	  Enable the s390 architectural random number generation API
550	  to provide random data for all consumers within the Linux
551	  kernel.
552
553	  When enabled the arch_random_* functions declared in linux/random.h
554	  are implemented. The implementation is based on the s390 CPACF
555	  instruction subfunction TRNG which provides a real true random
556	  number generator.
557
558	  If unsure, say Y.
559
560config KERNEL_NOBP
561	def_bool n
562	prompt "Enable modified branch prediction for the kernel by default"
563	help
564	  If this option is selected the kernel will switch to a modified
565	  branch prediction mode if the firmware interface is available.
566	  The modified branch prediction mode improves the behaviour in
567	  regard to speculative execution.
568
569	  With the option enabled the kernel parameter "nobp=0" or "nospec"
570	  can be used to run the kernel in the normal branch prediction mode.
571
572	  With the option disabled the modified branch prediction mode is
573	  enabled with the "nobp=1" kernel parameter.
574
575	  If unsure, say N.
576
577config EXPOLINE
578	def_bool n
579	prompt "Avoid speculative indirect branches in the kernel"
580	help
581	  Compile the kernel with the expoline compiler options to guard
582	  against kernel-to-user data leaks by avoiding speculative indirect
583	  branches.
584	  Requires a compiler with -mindirect-branch=thunk support for full
585	  protection. The kernel may run slower.
586
587	  If unsure, say N.
588
589choice
590	prompt "Expoline default"
591	depends on EXPOLINE
592	default EXPOLINE_FULL
593
594config EXPOLINE_OFF
595	bool "spectre_v2=off"
596
597config EXPOLINE_AUTO
598	bool "spectre_v2=auto"
599
600config EXPOLINE_FULL
601	bool "spectre_v2=on"
602
603endchoice
604
605endmenu
606
607menu "Memory setup"
608
609config ARCH_SPARSEMEM_ENABLE
610	def_bool y
611	select SPARSEMEM_VMEMMAP_ENABLE
612	select SPARSEMEM_VMEMMAP
613
614config ARCH_SPARSEMEM_DEFAULT
615	def_bool y
616
617config ARCH_SELECT_MEMORY_MODEL
618	def_bool y
619
620config ARCH_ENABLE_MEMORY_HOTPLUG
621	def_bool y if SPARSEMEM
622
623config ARCH_ENABLE_MEMORY_HOTREMOVE
624	def_bool y
625
626config ARCH_ENABLE_SPLIT_PMD_PTLOCK
627	def_bool y
628
629config FORCE_MAX_ZONEORDER
630	int
631	default "9"
632
633config MAX_PHYSMEM_BITS
634	int "Maximum size of supported physical memory in bits (42-53)"
635	range 42 53
636	default "46"
637	help
638	  This option specifies the maximum supported size of physical memory
639	  in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
640	  Increasing the number of bits also increases the kernel image size.
641	  By default 46 bits (64TB) are supported.
642
643config PACK_STACK
644	def_bool y
645	prompt "Pack kernel stack"
646	help
647	  This option enables the compiler option -mkernel-backchain if it
648	  is available. If the option is available the compiler supports
649	  the new stack layout which dramatically reduces the minimum stack
650	  frame size. With an old compiler a non-leaf function needs a
651	  minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
652	  -mkernel-backchain the minimum size drops to 16 byte on 31 bit
653	  and 24 byte on 64 bit.
654
655	  Say Y if you are unsure.
656
657config CHECK_STACK
658	def_bool y
659	depends on !VMAP_STACK
660	prompt "Detect kernel stack overflow"
661	help
662	  This option enables the compiler option -mstack-guard and
663	  -mstack-size if they are available. If the compiler supports them
664	  it will emit additional code to each function prolog to trigger
665	  an illegal operation if the kernel stack is about to overflow.
666
667	  Say N if you are unsure.
668
669config STACK_GUARD
670	int "Size of the guard area (128-1024)"
671	range 128 1024
672	depends on CHECK_STACK
673	default "256"
674	help
675	  This allows you to specify the size of the guard area at the lower
676	  end of the kernel stack. If the kernel stack points into the guard
677	  area on function entry an illegal operation is triggered. The size
678	  needs to be a power of 2. Please keep in mind that the size of an
679	  interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
680	  The minimum size for the stack guard should be 256 for 31 bit and
681	  512 for 64 bit.
682
683config WARN_DYNAMIC_STACK
684	def_bool n
685	prompt "Emit compiler warnings for function with dynamic stack usage"
686	help
687	  This option enables the compiler option -mwarn-dynamicstack. If the
688	  compiler supports this options generates warnings for functions
689	  that dynamically allocate stack space using alloca.
690
691	  Say N if you are unsure.
692
693endmenu
694
695menu "I/O subsystem"
696
697config QDIO
698	def_tristate y
699	prompt "QDIO support"
700	---help---
701	  This driver provides the Queued Direct I/O base support for
702	  IBM System z.
703
704	  To compile this driver as a module, choose M here: the
705	  module will be called qdio.
706
707	  If unsure, say Y.
708
709menuconfig PCI
710	bool "PCI support"
711	select PCI_MSI
712	select IOMMU_HELPER
713	select IOMMU_SUPPORT
714	select NEED_DMA_MAP_STATE
715	select NEED_SG_DMA_LENGTH
716
717	help
718	  Enable PCI support.
719
720if PCI
721
722config PCI_NR_FUNCTIONS
723	int "Maximum number of PCI functions (1-4096)"
724	range 1 4096
725	default "128"
726	help
727	  This allows you to specify the maximum number of PCI functions which
728	  this kernel will support.
729
730source "drivers/pci/Kconfig"
731
732endif	# PCI
733
734config PCI_DOMAINS
735	def_bool PCI
736
737config HAS_IOMEM
738	def_bool PCI
739
740config CHSC_SCH
741	def_tristate m
742	prompt "Support for CHSC subchannels"
743	help
744	  This driver allows usage of CHSC subchannels. A CHSC subchannel
745	  is usually present on LPAR only.
746	  The driver creates a device /dev/chsc, which may be used to
747	  obtain I/O configuration information about the machine and
748	  to issue asynchronous chsc commands (DANGEROUS).
749	  You will usually only want to use this interface on a special
750	  LPAR designated for system management.
751
752	  To compile this driver as a module, choose M here: the
753	  module will be called chsc_sch.
754
755	  If unsure, say N.
756
757config SCM_BUS
758	def_bool y
759	prompt "SCM bus driver"
760	help
761	  Bus driver for Storage Class Memory.
762
763config EADM_SCH
764	def_tristate m
765	prompt "Support for EADM subchannels"
766	depends on SCM_BUS
767	help
768	  This driver allows usage of EADM subchannels. EADM subchannels act
769	  as a communication vehicle for SCM increments.
770
771	  To compile this driver as a module, choose M here: the
772	  module will be called eadm_sch.
773
774config VFIO_CCW
775	def_tristate n
776	prompt "Support for VFIO-CCW subchannels"
777	depends on S390_CCW_IOMMU && VFIO_MDEV
778	help
779	  This driver allows usage of I/O subchannels via VFIO-CCW.
780
781	  To compile this driver as a module, choose M here: the
782	  module will be called vfio_ccw.
783
784config VFIO_AP
785	def_tristate n
786	prompt "VFIO support for AP devices"
787	depends on S390_AP_IOMMU && VFIO_MDEV_DEVICE && KVM
788	help
789		This driver grants access to Adjunct Processor (AP) devices
790		via the VFIO mediated device interface.
791
792		To compile this driver as a module, choose M here: the module
793		will be called vfio_ap.
794
795endmenu
796
797menu "Dump support"
798
799config CRASH_DUMP
800	bool "kernel crash dumps"
801	depends on SMP
802	select KEXEC
803	help
804	  Generate crash dump after being started by kexec.
805	  Crash dump kernels are loaded in the main kernel with kexec-tools
806	  into a specially reserved region and then later executed after
807	  a crash by kdump/kexec.
808	  Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
809	  This option also enables s390 zfcpdump.
810	  See also <file:Documentation/s390/zfcpdump.txt>
811
812endmenu
813
814config SECCOMP
815	def_bool y
816	prompt "Enable seccomp to safely compute untrusted bytecode"
817	depends on PROC_FS
818	help
819	  This kernel feature is useful for number crunching applications
820	  that may need to compute untrusted bytecode during their
821	  execution. By using pipes or other transports made available to
822	  the process as file descriptors supporting the read/write
823	  syscalls, it's possible to isolate those applications in
824	  their own address space using seccomp. Once seccomp is
825	  enabled via /proc/<pid>/seccomp, it cannot be disabled
826	  and the task is only allowed to execute a few safe syscalls
827	  defined by each seccomp mode.
828
829	  If unsure, say Y.
830
831menu "Power Management"
832
833config ARCH_HIBERNATION_POSSIBLE
834	def_bool y
835
836source "kernel/power/Kconfig"
837
838endmenu
839
840config PCMCIA
841	def_bool n
842
843config CCW
844	def_bool y
845
846config HAVE_PNETID
847	tristate
848	default (SMC || CCWGROUP)
849
850menu "Virtualization"
851
852config PFAULT
853	def_bool y
854	prompt "Pseudo page fault support"
855	help
856	  Select this option, if you want to use PFAULT pseudo page fault
857	  handling under VM. If running native or in LPAR, this option
858	  has no effect. If your VM does not support PFAULT, PAGEEX
859	  pseudo page fault handling will be used.
860	  Note that VM 4.2 supports PFAULT but has a bug in its
861	  implementation that causes some problems.
862	  Everybody who wants to run Linux under VM != VM4.2 should select
863	  this option.
864
865config CMM
866	def_tristate n
867	prompt "Cooperative memory management"
868	help
869	  Select this option, if you want to enable the kernel interface
870	  to reduce the memory size of the system. This is accomplished
871	  by allocating pages of memory and put them "on hold". This only
872	  makes sense for a system running under VM where the unused pages
873	  will be reused by VM for other guest systems. The interface
874	  allows an external monitor to balance memory of many systems.
875	  Everybody who wants to run Linux under VM should select this
876	  option.
877
878config CMM_IUCV
879	def_bool y
880	prompt "IUCV special message interface to cooperative memory management"
881	depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
882	help
883	  Select this option to enable the special message interface to
884	  the cooperative memory management.
885
886config APPLDATA_BASE
887	def_bool n
888	prompt "Linux - VM Monitor Stream, base infrastructure"
889	depends on PROC_FS
890	help
891	  This provides a kernel interface for creating and updating z/VM APPLDATA
892	  monitor records. The monitor records are updated at certain time
893	  intervals, once the timer is started.
894	  Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
895	  i.e. enables or disables monitoring on the Linux side.
896	  A custom interval value (in seconds) can be written to
897	  /proc/appldata/interval.
898
899	  Defaults are 60 seconds interval and timer off.
900	  The /proc entries can also be read from, showing the current settings.
901
902config APPLDATA_MEM
903	def_tristate m
904	prompt "Monitor memory management statistics"
905	depends on APPLDATA_BASE && VM_EVENT_COUNTERS
906	help
907	  This provides memory management related data to the Linux - VM Monitor
908	  Stream, like paging/swapping rate, memory utilisation, etc.
909	  Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
910	  APPLDATA monitor record, i.e. enables or disables monitoring this record
911	  on the z/VM side.
912
913	  Default is disabled.
914	  The /proc entry can also be read from, showing the current settings.
915
916	  This can also be compiled as a module, which will be called
917	  appldata_mem.o.
918
919config APPLDATA_OS
920	def_tristate m
921	prompt "Monitor OS statistics"
922	depends on APPLDATA_BASE
923	help
924	  This provides OS related data to the Linux - VM Monitor Stream, like
925	  CPU utilisation, etc.
926	  Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
927	  APPLDATA monitor record, i.e. enables or disables monitoring this record
928	  on the z/VM side.
929
930	  Default is disabled.
931	  This can also be compiled as a module, which will be called
932	  appldata_os.o.
933
934config APPLDATA_NET_SUM
935	def_tristate m
936	prompt "Monitor overall network statistics"
937	depends on APPLDATA_BASE && NET
938	help
939	  This provides network related data to the Linux - VM Monitor Stream,
940	  currently there is only a total sum of network I/O statistics, no
941	  per-interface data.
942	  Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
943	  APPLDATA monitor record, i.e. enables or disables monitoring this record
944	  on the z/VM side.
945
946	  Default is disabled.
947	  This can also be compiled as a module, which will be called
948	  appldata_net_sum.o.
949
950config S390_HYPFS_FS
951	def_bool y
952	prompt "s390 hypervisor file system support"
953	select SYS_HYPERVISOR
954	help
955	  This is a virtual file system intended to provide accounting
956	  information in an s390 hypervisor environment.
957
958source "arch/s390/kvm/Kconfig"
959
960config S390_GUEST
961	def_bool y
962	prompt "s390 support for virtio devices"
963	select TTY
964	select VIRTUALIZATION
965	select VIRTIO
966	select VIRTIO_CONSOLE
967	help
968	  Enabling this option adds support for virtio based paravirtual device
969	  drivers on s390.
970
971	  Select this option if you want to run the kernel as a guest under
972	  the KVM hypervisor.
973
974endmenu
975