1# SPDX-License-Identifier: GPL-2.0
2config MMU
3	def_bool y
4
5config CPU_BIG_ENDIAN
6	def_bool y
7
8config LOCKDEP_SUPPORT
9	def_bool y
10
11config STACKTRACE_SUPPORT
12	def_bool y
13
14config ARCH_HAS_ILOG2_U32
15	def_bool n
16
17config ARCH_HAS_ILOG2_U64
18	def_bool n
19
20config GENERIC_HWEIGHT
21	def_bool y
22
23config GENERIC_BUG
24	def_bool y if BUG
25
26config GENERIC_BUG_RELATIVE_POINTERS
27	def_bool y
28
29config GENERIC_LOCKBREAK
30	def_bool y if PREEMPTION
31
32config PGSTE
33	def_bool y if KVM
34
35config AUDIT_ARCH
36	def_bool y
37
38config NO_IOPORT_MAP
39	def_bool y
40
41config PCI_QUIRKS
42	def_bool n
43
44config ARCH_SUPPORTS_UPROBES
45	def_bool y
46
47config KASAN_SHADOW_OFFSET
48	hex
49	depends on KASAN
50	default 0x1C000000000000
51
52config S390
53	def_bool y
54	#
55	# Note: keep this list sorted alphabetically
56	#
57	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
58	select ARCH_32BIT_USTAT_F_TINODE
59	select ARCH_BINFMT_ELF_STATE
60	select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM
61	select ARCH_ENABLE_MEMORY_HOTREMOVE
62	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
63	select ARCH_HAS_DEBUG_VM_PGTABLE
64	select ARCH_HAS_DEBUG_WX
65	select ARCH_HAS_DEVMEM_IS_ALLOWED
66	select ARCH_HAS_ELF_RANDOMIZE
67	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
68	select ARCH_HAS_FORTIFY_SOURCE
69	select ARCH_HAS_GCOV_PROFILE_ALL
70	select ARCH_HAS_GIGANTIC_PAGE
71	select ARCH_HAS_KCOV
72	select ARCH_HAS_MEM_ENCRYPT
73	select ARCH_HAS_PTE_SPECIAL
74	select ARCH_HAS_SCALED_CPUTIME
75	select ARCH_HAS_SET_MEMORY
76	select ARCH_HAS_STRICT_KERNEL_RWX
77	select ARCH_HAS_STRICT_MODULE_RWX
78	select ARCH_HAS_SYSCALL_WRAPPER
79	select ARCH_HAS_UBSAN_SANITIZE_ALL
80	select ARCH_HAS_VDSO_DATA
81	select ARCH_HAVE_NMI_SAFE_CMPXCHG
82	select ARCH_INLINE_READ_LOCK
83	select ARCH_INLINE_READ_LOCK_BH
84	select ARCH_INLINE_READ_LOCK_IRQ
85	select ARCH_INLINE_READ_LOCK_IRQSAVE
86	select ARCH_INLINE_READ_TRYLOCK
87	select ARCH_INLINE_READ_UNLOCK
88	select ARCH_INLINE_READ_UNLOCK_BH
89	select ARCH_INLINE_READ_UNLOCK_IRQ
90	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
91	select ARCH_INLINE_SPIN_LOCK
92	select ARCH_INLINE_SPIN_LOCK_BH
93	select ARCH_INLINE_SPIN_LOCK_IRQ
94	select ARCH_INLINE_SPIN_LOCK_IRQSAVE
95	select ARCH_INLINE_SPIN_TRYLOCK
96	select ARCH_INLINE_SPIN_TRYLOCK_BH
97	select ARCH_INLINE_SPIN_UNLOCK
98	select ARCH_INLINE_SPIN_UNLOCK_BH
99	select ARCH_INLINE_SPIN_UNLOCK_IRQ
100	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
101	select ARCH_INLINE_WRITE_LOCK
102	select ARCH_INLINE_WRITE_LOCK_BH
103	select ARCH_INLINE_WRITE_LOCK_IRQ
104	select ARCH_INLINE_WRITE_LOCK_IRQSAVE
105	select ARCH_INLINE_WRITE_TRYLOCK
106	select ARCH_INLINE_WRITE_UNLOCK
107	select ARCH_INLINE_WRITE_UNLOCK_BH
108	select ARCH_INLINE_WRITE_UNLOCK_IRQ
109	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
110	select ARCH_STACKWALK
111	select ARCH_SUPPORTS_ATOMIC_RMW
112	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
113	select ARCH_SUPPORTS_HUGETLBFS
114	select ARCH_SUPPORTS_NUMA_BALANCING
115	select ARCH_USE_BUILTIN_BSWAP
116	select ARCH_USE_CMPXCHG_LOCKREF
117	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
118	select ARCH_WANTS_NO_INSTR
119	select ARCH_WANT_DEFAULT_BPF_JIT
120	select ARCH_WANT_IPC_PARSE_VERSION
121	select BUILDTIME_TABLE_SORT
122	select CLONE_BACKWARDS2
123	select CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES
124	select DMA_OPS if PCI
125	select DYNAMIC_FTRACE if FUNCTION_TRACER
126	select GENERIC_ALLOCATOR
127	select GENERIC_CPU_AUTOPROBE
128	select GENERIC_CPU_VULNERABILITIES
129	select GENERIC_ENTRY
130	select GENERIC_FIND_FIRST_BIT
131	select GENERIC_GETTIMEOFDAY
132	select GENERIC_PTDUMP
133	select GENERIC_SMP_IDLE_THREAD
134	select GENERIC_TIME_VSYSCALL
135	select GENERIC_VDSO_TIME_NS
136	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
137	select HAVE_ARCH_AUDITSYSCALL
138	select HAVE_ARCH_JUMP_LABEL
139	select HAVE_ARCH_JUMP_LABEL_RELATIVE
140	select HAVE_ARCH_KASAN
141	select HAVE_ARCH_KASAN_VMALLOC
142	select HAVE_ARCH_KCSAN
143	select HAVE_ARCH_KFENCE
144	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
145	select HAVE_ARCH_SECCOMP_FILTER
146	select HAVE_ARCH_SOFT_DIRTY
147	select HAVE_ARCH_TRACEHOOK
148	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
149	select HAVE_ARCH_VMAP_STACK
150	select HAVE_ASM_MODVERSIONS
151	select HAVE_CMPXCHG_DOUBLE
152	select HAVE_CMPXCHG_LOCAL
153	select HAVE_DEBUG_KMEMLEAK
154	select HAVE_DMA_CONTIGUOUS
155	select HAVE_DYNAMIC_FTRACE
156	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
157	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
158	select HAVE_DYNAMIC_FTRACE_WITH_REGS
159	select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
160	select HAVE_EFFICIENT_UNALIGNED_ACCESS
161	select HAVE_FAST_GUP
162	select HAVE_FENTRY
163	select HAVE_FTRACE_MCOUNT_RECORD
164	select HAVE_FUNCTION_ARG_ACCESS_API
165	select HAVE_FUNCTION_ERROR_INJECTION
166	select HAVE_FUNCTION_GRAPH_TRACER
167	select HAVE_FUNCTION_TRACER
168	select HAVE_FUTEX_CMPXCHG if FUTEX
169	select HAVE_GCC_PLUGINS
170	select HAVE_GENERIC_VDSO
171	select HAVE_IOREMAP_PROT if PCI
172	select HAVE_KERNEL_BZIP2
173	select HAVE_KERNEL_GZIP
174	select HAVE_KERNEL_LZ4
175	select HAVE_KERNEL_LZMA
176	select HAVE_KERNEL_LZO
177	select HAVE_KERNEL_UNCOMPRESSED
178	select HAVE_KERNEL_XZ
179	select HAVE_KERNEL_ZSTD
180	select HAVE_KPROBES
181	select HAVE_KPROBES_ON_FTRACE
182	select HAVE_KRETPROBES
183	select HAVE_KVM
184	select HAVE_LIVEPATCH
185	select HAVE_MEMBLOCK_PHYS_MAP
186	select HAVE_MOD_ARCH_SPECIFIC
187	select HAVE_NMI
188	select HAVE_NOP_MCOUNT
189	select HAVE_PCI
190	select HAVE_PERF_EVENTS
191	select HAVE_PERF_REGS
192	select HAVE_PERF_USER_STACK_DUMP
193	select HAVE_REGS_AND_STACK_ACCESS_API
194	select HAVE_RELIABLE_STACKTRACE
195	select HAVE_RSEQ
196	select HAVE_SAMPLE_FTRACE_DIRECT
197	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
198	select HAVE_SOFTIRQ_ON_OWN_STACK
199	select HAVE_SYSCALL_TRACEPOINTS
200	select HAVE_VIRT_CPU_ACCOUNTING
201	select HAVE_VIRT_CPU_ACCOUNTING_IDLE
202	select IOMMU_HELPER		if PCI
203	select IOMMU_SUPPORT		if PCI
204	select MMU_GATHER_NO_GATHER
205	select MMU_GATHER_RCU_TABLE_FREE
206	select MODULES_USE_ELF_RELA
207	select NEED_DMA_MAP_STATE	if PCI
208	select NEED_SG_DMA_LENGTH	if PCI
209	select OLD_SIGACTION
210	select OLD_SIGSUSPEND3
211	select PCI_DOMAINS		if PCI
212	select PCI_MSI			if PCI
213	select PCI_MSI_ARCH_FALLBACKS	if PCI_MSI
214	select SPARSE_IRQ
215	select SWIOTLB
216	select SYSCTL_EXCEPTION_TRACE
217	select THREAD_INFO_IN_TASK
218	select TRACE_IRQFLAGS_SUPPORT
219	select TTY
220	select VIRT_CPU_ACCOUNTING
221	select ZONE_DMA
222	# Note: keep the above list sorted alphabetically
223
224config SCHED_OMIT_FRAME_POINTER
225	def_bool y
226
227config PGTABLE_LEVELS
228	int
229	default 5
230
231source "kernel/livepatch/Kconfig"
232
233menu "Processor type and features"
234
235config HAVE_MARCH_Z900_FEATURES
236	def_bool n
237
238config HAVE_MARCH_Z990_FEATURES
239	def_bool n
240	select HAVE_MARCH_Z900_FEATURES
241
242config HAVE_MARCH_Z9_109_FEATURES
243	def_bool n
244	select HAVE_MARCH_Z990_FEATURES
245
246config HAVE_MARCH_Z10_FEATURES
247	def_bool n
248	select HAVE_MARCH_Z9_109_FEATURES
249
250config HAVE_MARCH_Z196_FEATURES
251	def_bool n
252	select HAVE_MARCH_Z10_FEATURES
253
254config HAVE_MARCH_ZEC12_FEATURES
255	def_bool n
256	select HAVE_MARCH_Z196_FEATURES
257
258config HAVE_MARCH_Z13_FEATURES
259	def_bool n
260	select HAVE_MARCH_ZEC12_FEATURES
261
262config HAVE_MARCH_Z14_FEATURES
263	def_bool n
264	select HAVE_MARCH_Z13_FEATURES
265
266config HAVE_MARCH_Z15_FEATURES
267	def_bool n
268	select HAVE_MARCH_Z14_FEATURES
269
270choice
271	prompt "Processor type"
272	default MARCH_Z196
273
274config MARCH_Z900
275	bool "IBM zSeries model z800 and z900"
276	select HAVE_MARCH_Z900_FEATURES
277	depends on $(cc-option,-march=z900)
278	help
279	  Select this to enable optimizations for model z800/z900 (2064 and
280	  2066 series). This will enable some optimizations that are not
281	  available on older ESA/390 (31 Bit) only CPUs.
282
283config MARCH_Z990
284	bool "IBM zSeries model z890 and z990"
285	select HAVE_MARCH_Z990_FEATURES
286	depends on $(cc-option,-march=z990)
287	help
288	  Select this to enable optimizations for model z890/z990 (2084 and
289	  2086 series). The kernel will be slightly faster but will not work
290	  on older machines.
291
292config MARCH_Z9_109
293	bool "IBM System z9"
294	select HAVE_MARCH_Z9_109_FEATURES
295	depends on $(cc-option,-march=z9-109)
296	help
297	  Select this to enable optimizations for IBM System z9 (2094 and
298	  2096 series). The kernel will be slightly faster but will not work
299	  on older machines.
300
301config MARCH_Z10
302	bool "IBM System z10"
303	select HAVE_MARCH_Z10_FEATURES
304	depends on $(cc-option,-march=z10)
305	help
306	  Select this to enable optimizations for IBM System z10 (2097 and
307	  2098 series). The kernel will be slightly faster but will not work
308	  on older machines.
309
310config MARCH_Z196
311	bool "IBM zEnterprise 114 and 196"
312	select HAVE_MARCH_Z196_FEATURES
313	depends on $(cc-option,-march=z196)
314	help
315	  Select this to enable optimizations for IBM zEnterprise 114 and 196
316	  (2818 and 2817 series). The kernel will be slightly faster but will
317	  not work on older machines.
318
319config MARCH_ZEC12
320	bool "IBM zBC12 and zEC12"
321	select HAVE_MARCH_ZEC12_FEATURES
322	depends on $(cc-option,-march=zEC12)
323	help
324	  Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
325	  2827 series). The kernel will be slightly faster but will not work on
326	  older machines.
327
328config MARCH_Z13
329	bool "IBM z13s and z13"
330	select HAVE_MARCH_Z13_FEATURES
331	depends on $(cc-option,-march=z13)
332	help
333	  Select this to enable optimizations for IBM z13s and z13 (2965 and
334	  2964 series). The kernel will be slightly faster but will not work on
335	  older machines.
336
337config MARCH_Z14
338	bool "IBM z14 ZR1 and z14"
339	select HAVE_MARCH_Z14_FEATURES
340	depends on $(cc-option,-march=z14)
341	help
342	  Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
343	  and 3906 series). The kernel will be slightly faster but will not
344	  work on older machines.
345
346config MARCH_Z15
347	bool "IBM z15"
348	select HAVE_MARCH_Z15_FEATURES
349	depends on $(cc-option,-march=z15)
350	help
351	  Select this to enable optimizations for IBM z15 (8562
352	  and 8561 series). The kernel will be slightly faster but will not
353	  work on older machines.
354
355endchoice
356
357config MARCH_Z900_TUNE
358	def_bool TUNE_Z900 || MARCH_Z900 && TUNE_DEFAULT
359
360config MARCH_Z990_TUNE
361	def_bool TUNE_Z990 || MARCH_Z990 && TUNE_DEFAULT
362
363config MARCH_Z9_109_TUNE
364	def_bool TUNE_Z9_109 || MARCH_Z9_109 && TUNE_DEFAULT
365
366config MARCH_Z10_TUNE
367	def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
368
369config MARCH_Z196_TUNE
370	def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
371
372config MARCH_ZEC12_TUNE
373	def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
374
375config MARCH_Z13_TUNE
376	def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
377
378config MARCH_Z14_TUNE
379	def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
380
381config MARCH_Z15_TUNE
382	def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT
383
384choice
385	prompt "Tune code generation"
386	default TUNE_DEFAULT
387	help
388	  Cause the compiler to tune (-mtune) the generated code for a machine.
389	  This will make the code run faster on the selected machine but
390	  somewhat slower on other machines.
391	  This option only changes how the compiler emits instructions, not the
392	  selection of instructions itself, so the resulting kernel will run on
393	  all other machines.
394
395config TUNE_DEFAULT
396	bool "Default"
397	help
398	  Tune the generated code for the target processor for which the kernel
399	  will be compiled.
400
401config TUNE_Z900
402	bool "IBM zSeries model z800 and z900"
403	depends on $(cc-option,-mtune=z900)
404
405config TUNE_Z990
406	bool "IBM zSeries model z890 and z990"
407	depends on $(cc-option,-mtune=z990)
408
409config TUNE_Z9_109
410	bool "IBM System z9"
411	depends on $(cc-option,-mtune=z9-109)
412
413config TUNE_Z10
414	bool "IBM System z10"
415	depends on $(cc-option,-mtune=z10)
416
417config TUNE_Z196
418	bool "IBM zEnterprise 114 and 196"
419	depends on $(cc-option,-mtune=z196)
420
421config TUNE_ZEC12
422	bool "IBM zBC12 and zEC12"
423	depends on $(cc-option,-mtune=zEC12)
424
425config TUNE_Z13
426	bool "IBM z13s and z13"
427	depends on $(cc-option,-mtune=z13)
428
429config TUNE_Z14
430	bool "IBM z14 ZR1 and z14"
431	depends on $(cc-option,-mtune=z14)
432
433config TUNE_Z15
434	bool "IBM z15"
435	depends on $(cc-option,-mtune=z15)
436
437endchoice
438
439config 64BIT
440	def_bool y
441
442config COMMAND_LINE_SIZE
443	int "Maximum size of kernel command line"
444	default 4096
445	range 896 1048576
446	help
447	  This allows you to specify the maximum length of the kernel command
448	  line.
449
450config COMPAT
451	def_bool y
452	prompt "Kernel support for 31 bit emulation"
453	select ARCH_WANT_OLD_COMPAT_IPC
454	select COMPAT_OLD_SIGACTION
455	select HAVE_UID16
456	depends on MULTIUSER
457	depends on !CC_IS_CLANG
458	help
459	  Select this option if you want to enable your system kernel to
460	  handle system-calls from ELF binaries for 31 bit ESA.  This option
461	  (and some other stuff like libraries and such) is needed for
462	  executing 31 bit applications.  It is safe to say "Y".
463
464config SYSVIPC_COMPAT
465	def_bool y if COMPAT && SYSVIPC
466
467config SMP
468	def_bool y
469
470config NR_CPUS
471	int "Maximum number of CPUs (2-512)"
472	range 2 512
473	default "64"
474	help
475	  This allows you to specify the maximum number of CPUs which this
476	  kernel will support. The maximum supported value is 512 and the
477	  minimum value which makes sense is 2.
478
479	  This is purely to save memory - each supported CPU adds
480	  approximately sixteen kilobytes to the kernel image.
481
482config HOTPLUG_CPU
483	def_bool y
484
485config NUMA
486	bool "NUMA support"
487	depends on SCHED_TOPOLOGY
488	default n
489	help
490	  Enable NUMA support
491
492	  This option adds NUMA support to the kernel.
493
494config NODES_SHIFT
495	int
496	depends on NUMA
497	default "1"
498
499config SCHED_SMT
500	def_bool n
501
502config SCHED_MC
503	def_bool n
504
505config SCHED_BOOK
506	def_bool n
507
508config SCHED_DRAWER
509	def_bool n
510
511config SCHED_TOPOLOGY
512	def_bool y
513	prompt "Topology scheduler support"
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 KEXEC_SIG
546	bool "Verify kernel signature during kexec_file_load() syscall"
547	depends on KEXEC_FILE && MODULE_SIG_FORMAT
548	help
549	  This option makes kernel signature verification mandatory for
550	  the kexec_file_load() syscall.
551
552	  In addition to that option, you need to enable signature
553	  verification for the corresponding kernel image type being
554	  loaded in order for this to work.
555
556config ARCH_RANDOM
557	def_bool y
558	prompt "s390 architectural random number generation API"
559	help
560	  Enable the s390 architectural random number generation API
561	  to provide random data for all consumers within the Linux
562	  kernel.
563
564	  When enabled the arch_random_* functions declared in linux/random.h
565	  are implemented. The implementation is based on the s390 CPACF
566	  instruction subfunction TRNG which provides a real true random
567	  number generator.
568
569	  If unsure, say Y.
570
571config KERNEL_NOBP
572	def_bool n
573	prompt "Enable modified branch prediction for the kernel by default"
574	help
575	  If this option is selected the kernel will switch to a modified
576	  branch prediction mode if the firmware interface is available.
577	  The modified branch prediction mode improves the behaviour in
578	  regard to speculative execution.
579
580	  With the option enabled the kernel parameter "nobp=0" or "nospec"
581	  can be used to run the kernel in the normal branch prediction mode.
582
583	  With the option disabled the modified branch prediction mode is
584	  enabled with the "nobp=1" kernel parameter.
585
586	  If unsure, say N.
587
588config EXPOLINE
589	def_bool n
590	prompt "Avoid speculative indirect branches in the kernel"
591	help
592	  Compile the kernel with the expoline compiler options to guard
593	  against kernel-to-user data leaks by avoiding speculative indirect
594	  branches.
595	  Requires a compiler with -mindirect-branch=thunk support for full
596	  protection. The kernel may run slower.
597
598	  If unsure, say N.
599
600choice
601	prompt "Expoline default"
602	depends on EXPOLINE
603	default EXPOLINE_FULL
604
605config EXPOLINE_OFF
606	bool "spectre_v2=off"
607
608config EXPOLINE_AUTO
609	bool "spectre_v2=auto"
610
611config EXPOLINE_FULL
612	bool "spectre_v2=on"
613
614endchoice
615
616config RELOCATABLE
617	bool "Build a relocatable kernel"
618	select MODULE_REL_CRCS if MODVERSIONS
619	default y
620	help
621	  This builds a kernel image that retains relocation information
622	  so it can be loaded at an arbitrary address.
623	  The kernel is linked as a position-independent executable (PIE)
624	  and contains dynamic relocations which are processed early in the
625	  bootup process.
626	  The relocations make the kernel image about 15% larger (compressed
627	  10%), but are discarded at runtime.
628
629config RANDOMIZE_BASE
630	bool "Randomize the address of the kernel image (KASLR)"
631	depends on RELOCATABLE
632	default y
633	help
634	  In support of Kernel Address Space Layout Randomization (KASLR),
635	  this randomizes the address at which the kernel image is loaded,
636	  as a security feature that deters exploit attempts relying on
637	  knowledge of the location of kernel internals.
638
639endmenu
640
641menu "Memory setup"
642
643config ARCH_SPARSEMEM_ENABLE
644	def_bool y
645	select SPARSEMEM_VMEMMAP_ENABLE
646	select SPARSEMEM_VMEMMAP
647
648config ARCH_SPARSEMEM_DEFAULT
649	def_bool y
650
651config MAX_PHYSMEM_BITS
652	int "Maximum size of supported physical memory in bits (42-53)"
653	range 42 53
654	default "46"
655	help
656	  This option specifies the maximum supported size of physical memory
657	  in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
658	  Increasing the number of bits also increases the kernel image size.
659	  By default 46 bits (64TB) are supported.
660
661config PACK_STACK
662	def_bool y
663	prompt "Pack kernel stack"
664	help
665	  This option enables the compiler option -mkernel-backchain if it
666	  is available. If the option is available the compiler supports
667	  the new stack layout which dramatically reduces the minimum stack
668	  frame size. With an old compiler a non-leaf function needs a
669	  minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
670	  -mkernel-backchain the minimum size drops to 16 byte on 31 bit
671	  and 24 byte on 64 bit.
672
673	  Say Y if you are unsure.
674
675config CHECK_STACK
676	def_bool y
677	depends on !VMAP_STACK
678	prompt "Detect kernel stack overflow"
679	help
680	  This option enables the compiler option -mstack-guard and
681	  -mstack-size if they are available. If the compiler supports them
682	  it will emit additional code to each function prolog to trigger
683	  an illegal operation if the kernel stack is about to overflow.
684
685	  Say N if you are unsure.
686
687config STACK_GUARD
688	int "Size of the guard area (128-1024)"
689	range 128 1024
690	depends on CHECK_STACK
691	default "256"
692	help
693	  This allows you to specify the size of the guard area at the lower
694	  end of the kernel stack. If the kernel stack points into the guard
695	  area on function entry an illegal operation is triggered. The size
696	  needs to be a power of 2. Please keep in mind that the size of an
697	  interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
698	  The minimum size for the stack guard should be 256 for 31 bit and
699	  512 for 64 bit.
700
701endmenu
702
703menu "I/O subsystem"
704
705config QDIO
706	def_tristate y
707	prompt "QDIO support"
708	help
709	  This driver provides the Queued Direct I/O base support for
710	  IBM System z.
711
712	  To compile this driver as a module, choose M here: the
713	  module will be called qdio.
714
715	  If unsure, say Y.
716
717if PCI
718
719config PCI_NR_FUNCTIONS
720	int "Maximum number of PCI functions (1-4096)"
721	range 1 4096
722	default "512"
723	help
724	  This allows you to specify the maximum number of PCI functions which
725	  this kernel will support.
726
727endif # PCI
728
729config HAS_IOMEM
730	def_bool PCI
731
732config CHSC_SCH
733	def_tristate m
734	prompt "Support for CHSC subchannels"
735	help
736	  This driver allows usage of CHSC subchannels. A CHSC subchannel
737	  is usually present on LPAR only.
738	  The driver creates a device /dev/chsc, which may be used to
739	  obtain I/O configuration information about the machine and
740	  to issue asynchronous chsc commands (DANGEROUS).
741	  You will usually only want to use this interface on a special
742	  LPAR designated for system management.
743
744	  To compile this driver as a module, choose M here: the
745	  module will be called chsc_sch.
746
747	  If unsure, say N.
748
749config SCM_BUS
750	def_bool y
751	prompt "SCM bus driver"
752	help
753	  Bus driver for Storage Class Memory.
754
755config EADM_SCH
756	def_tristate m
757	prompt "Support for EADM subchannels"
758	depends on SCM_BUS
759	help
760	  This driver allows usage of EADM subchannels. EADM subchannels act
761	  as a communication vehicle for SCM increments.
762
763	  To compile this driver as a module, choose M here: the
764	  module will be called eadm_sch.
765
766config VFIO_CCW
767	def_tristate n
768	prompt "Support for VFIO-CCW subchannels"
769	depends on S390_CCW_IOMMU && VFIO_MDEV
770	help
771	  This driver allows usage of I/O subchannels via VFIO-CCW.
772
773	  To compile this driver as a module, choose M here: the
774	  module will be called vfio_ccw.
775
776config VFIO_AP
777	def_tristate n
778	prompt "VFIO support for AP devices"
779	depends on S390_AP_IOMMU && VFIO_MDEV && KVM
780	depends on ZCRYPT
781	help
782		This driver grants access to Adjunct Processor (AP) devices
783		via the VFIO mediated device interface.
784
785		To compile this driver as a module, choose M here: the module
786		will be called vfio_ap.
787
788endmenu
789
790menu "Dump support"
791
792config CRASH_DUMP
793	bool "kernel crash dumps"
794	select KEXEC
795	help
796	  Generate crash dump after being started by kexec.
797	  Crash dump kernels are loaded in the main kernel with kexec-tools
798	  into a specially reserved region and then later executed after
799	  a crash by kdump/kexec.
800	  Refer to <file:Documentation/s390/zfcpdump.rst> for more details on this.
801	  This option also enables s390 zfcpdump.
802	  See also <file:Documentation/s390/zfcpdump.rst>
803
804endmenu
805
806config CCW
807	def_bool y
808
809config HAVE_PNETID
810	tristate
811	default (SMC || CCWGROUP)
812
813menu "Virtualization"
814
815config PROTECTED_VIRTUALIZATION_GUEST
816	def_bool n
817	prompt "Protected virtualization guest support"
818	select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
819	help
820	  Select this option, if you want to be able to run this
821	  kernel as a protected virtualization KVM guest.
822	  Protected virtualization capable machines have a mini hypervisor
823	  located at machine level (an ultravisor). With help of the
824	  Ultravisor, KVM will be able to run "protected" VMs, special
825	  VMs whose memory and management data are unavailable to KVM.
826
827config PFAULT
828	def_bool y
829	prompt "Pseudo page fault support"
830	help
831	  Select this option, if you want to use PFAULT pseudo page fault
832	  handling under VM. If running native or in LPAR, this option
833	  has no effect. If your VM does not support PFAULT, PAGEEX
834	  pseudo page fault handling will be used.
835	  Note that VM 4.2 supports PFAULT but has a bug in its
836	  implementation that causes some problems.
837	  Everybody who wants to run Linux under VM != VM4.2 should select
838	  this option.
839
840config CMM
841	def_tristate n
842	prompt "Cooperative memory management"
843	help
844	  Select this option, if you want to enable the kernel interface
845	  to reduce the memory size of the system. This is accomplished
846	  by allocating pages of memory and put them "on hold". This only
847	  makes sense for a system running under VM where the unused pages
848	  will be reused by VM for other guest systems. The interface
849	  allows an external monitor to balance memory of many systems.
850	  Everybody who wants to run Linux under VM should select this
851	  option.
852
853config CMM_IUCV
854	def_bool y
855	prompt "IUCV special message interface to cooperative memory management"
856	depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
857	help
858	  Select this option to enable the special message interface to
859	  the cooperative memory management.
860
861config APPLDATA_BASE
862	def_bool n
863	prompt "Linux - VM Monitor Stream, base infrastructure"
864	depends on PROC_SYSCTL
865	help
866	  This provides a kernel interface for creating and updating z/VM APPLDATA
867	  monitor records. The monitor records are updated at certain time
868	  intervals, once the timer is started.
869	  Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
870	  i.e. enables or disables monitoring on the Linux side.
871	  A custom interval value (in seconds) can be written to
872	  /proc/appldata/interval.
873
874	  Defaults are 60 seconds interval and timer off.
875	  The /proc entries can also be read from, showing the current settings.
876
877config APPLDATA_MEM
878	def_tristate m
879	prompt "Monitor memory management statistics"
880	depends on APPLDATA_BASE && VM_EVENT_COUNTERS
881	help
882	  This provides memory management related data to the Linux - VM Monitor
883	  Stream, like paging/swapping rate, memory utilisation, etc.
884	  Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
885	  APPLDATA monitor record, i.e. enables or disables monitoring this record
886	  on the z/VM side.
887
888	  Default is disabled.
889	  The /proc entry can also be read from, showing the current settings.
890
891	  This can also be compiled as a module, which will be called
892	  appldata_mem.o.
893
894config APPLDATA_OS
895	def_tristate m
896	prompt "Monitor OS statistics"
897	depends on APPLDATA_BASE
898	help
899	  This provides OS related data to the Linux - VM Monitor Stream, like
900	  CPU utilisation, etc.
901	  Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
902	  APPLDATA monitor record, i.e. enables or disables monitoring this record
903	  on the z/VM side.
904
905	  Default is disabled.
906	  This can also be compiled as a module, which will be called
907	  appldata_os.o.
908
909config APPLDATA_NET_SUM
910	def_tristate m
911	prompt "Monitor overall network statistics"
912	depends on APPLDATA_BASE && NET
913	help
914	  This provides network related data to the Linux - VM Monitor Stream,
915	  currently there is only a total sum of network I/O statistics, no
916	  per-interface data.
917	  Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
918	  APPLDATA monitor record, i.e. enables or disables monitoring this record
919	  on the z/VM side.
920
921	  Default is disabled.
922	  This can also be compiled as a module, which will be called
923	  appldata_net_sum.o.
924
925config S390_HYPFS_FS
926	def_bool y
927	prompt "s390 hypervisor file system support"
928	select SYS_HYPERVISOR
929	help
930	  This is a virtual file system intended to provide accounting
931	  information in an s390 hypervisor environment.
932
933source "arch/s390/kvm/Kconfig"
934
935config S390_GUEST
936	def_bool y
937	prompt "s390 support for virtio devices"
938	select TTY
939	select VIRTUALIZATION
940	select VIRTIO
941	help
942	  Enabling this option adds support for virtio based paravirtual device
943	  drivers on s390.
944
945	  Select this option if you want to run the kernel as a guest under
946	  the KVM hypervisor.
947
948endmenu
949
950menu "Selftests"
951
952config S390_UNWIND_SELFTEST
953	def_tristate n
954	depends on KUNIT
955	default KUNIT_ALL_TESTS
956	prompt "Test unwind functions"
957	help
958	  This option enables s390 specific stack unwinder testing kernel
959	  module. This option is not useful for distributions or general
960	  kernels, but only for kernel developers working on architecture code.
961
962	  Say N if you are unsure.
963
964config S390_KPROBES_SANITY_TEST
965	def_tristate n
966	prompt "Enable s390 specific kprobes tests"
967	depends on KPROBES
968	depends on KUNIT
969	help
970	  This option enables an s390 specific kprobes test module. This option
971	  is not useful for distributions or general kernels, but only for kernel
972	  developers working on architecture code.
973
974	  Say N if you are unsure.
975
976endmenu
977