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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_CSUM
30 bool
31 default y if KASAN
32
33config GENERIC_LOCKBREAK
34 def_bool y if PREEMPTION
35
36config PGSTE
37 def_bool y if KVM
38
39config AUDIT_ARCH
40 def_bool y
41
42config NO_IOPORT_MAP
43 def_bool y
44
45config PCI_QUIRKS
46 def_bool n
47
48config ARCH_SUPPORTS_UPROBES
49 def_bool y
50
51config KASAN_SHADOW_OFFSET
52 hex
53 depends on KASAN
54 default 0x1C000000000000
55
56config S390
57 def_bool y
58 #
59 # Note: keep this list sorted alphabetically
60 #
61 imply IMA_SECURE_AND_OR_TRUSTED_BOOT
62 select ALTERNATE_USER_ADDRESS_SPACE
63 select ARCH_32BIT_USTAT_F_TINODE
64 select ARCH_BINFMT_ELF_STATE
65 select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
66 select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM
67 select ARCH_ENABLE_MEMORY_HOTREMOVE
68 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
69 select ARCH_HAS_CURRENT_STACK_POINTER
70 select ARCH_HAS_DEBUG_VM_PGTABLE
71 select ARCH_HAS_DEBUG_WX
72 select ARCH_HAS_DEVMEM_IS_ALLOWED
73 select ARCH_HAS_ELF_RANDOMIZE
74 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
75 select ARCH_HAS_FORTIFY_SOURCE
76 select ARCH_HAS_GCOV_PROFILE_ALL
77 select ARCH_HAS_GIGANTIC_PAGE
78 select ARCH_HAS_KCOV
79 select ARCH_HAS_MEM_ENCRYPT
80 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
81 select ARCH_HAS_PTE_SPECIAL
82 select ARCH_HAS_SCALED_CPUTIME
83 select ARCH_HAS_SET_MEMORY
84 select ARCH_HAS_STRICT_KERNEL_RWX
85 select ARCH_HAS_STRICT_MODULE_RWX
86 select ARCH_HAS_SYSCALL_WRAPPER
87 select ARCH_HAS_UBSAN_SANITIZE_ALL
88 select ARCH_HAS_VDSO_DATA
89 select ARCH_HAVE_NMI_SAFE_CMPXCHG
90 select ARCH_INLINE_READ_LOCK
91 select ARCH_INLINE_READ_LOCK_BH
92 select ARCH_INLINE_READ_LOCK_IRQ
93 select ARCH_INLINE_READ_LOCK_IRQSAVE
94 select ARCH_INLINE_READ_TRYLOCK
95 select ARCH_INLINE_READ_UNLOCK
96 select ARCH_INLINE_READ_UNLOCK_BH
97 select ARCH_INLINE_READ_UNLOCK_IRQ
98 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
99 select ARCH_INLINE_SPIN_LOCK
100 select ARCH_INLINE_SPIN_LOCK_BH
101 select ARCH_INLINE_SPIN_LOCK_IRQ
102 select ARCH_INLINE_SPIN_LOCK_IRQSAVE
103 select ARCH_INLINE_SPIN_TRYLOCK
104 select ARCH_INLINE_SPIN_TRYLOCK_BH
105 select ARCH_INLINE_SPIN_UNLOCK
106 select ARCH_INLINE_SPIN_UNLOCK_BH
107 select ARCH_INLINE_SPIN_UNLOCK_IRQ
108 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
109 select ARCH_INLINE_WRITE_LOCK
110 select ARCH_INLINE_WRITE_LOCK_BH
111 select ARCH_INLINE_WRITE_LOCK_IRQ
112 select ARCH_INLINE_WRITE_LOCK_IRQSAVE
113 select ARCH_INLINE_WRITE_TRYLOCK
114 select ARCH_INLINE_WRITE_UNLOCK
115 select ARCH_INLINE_WRITE_UNLOCK_BH
116 select ARCH_INLINE_WRITE_UNLOCK_IRQ
117 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
118 select ARCH_STACKWALK
119 select ARCH_SUPPORTS_ATOMIC_RMW
120 select ARCH_SUPPORTS_DEBUG_PAGEALLOC
121 select ARCH_SUPPORTS_HUGETLBFS
122 select ARCH_SUPPORTS_NUMA_BALANCING
123 select ARCH_USE_BUILTIN_BSWAP
124 select ARCH_USE_CMPXCHG_LOCKREF
125 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
126 select ARCH_WANTS_NO_INSTR
127 select ARCH_WANT_DEFAULT_BPF_JIT
128 select ARCH_WANT_IPC_PARSE_VERSION
129 select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
130 select BUILDTIME_TABLE_SORT
131 select CLONE_BACKWARDS2
132 select DMA_OPS if PCI
133 select DYNAMIC_FTRACE if FUNCTION_TRACER
134 select GCC12_NO_ARRAY_BOUNDS
135 select GENERIC_ALLOCATOR
136 select GENERIC_CPU_AUTOPROBE
137 select GENERIC_CPU_VULNERABILITIES
138 select GENERIC_ENTRY
139 select GENERIC_GETTIMEOFDAY
140 select GENERIC_PTDUMP
141 select GENERIC_SMP_IDLE_THREAD
142 select GENERIC_TIME_VSYSCALL
143 select GENERIC_VDSO_TIME_NS
144 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
145 select HAVE_ARCH_AUDITSYSCALL
146 select HAVE_ARCH_JUMP_LABEL
147 select HAVE_ARCH_JUMP_LABEL_RELATIVE
148 select HAVE_ARCH_KASAN
149 select HAVE_ARCH_KASAN_VMALLOC
150 select HAVE_ARCH_KCSAN
151 select HAVE_ARCH_KFENCE
152 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
153 select HAVE_ARCH_SECCOMP_FILTER
154 select HAVE_ARCH_SOFT_DIRTY
155 select HAVE_ARCH_TRACEHOOK
156 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
157 select HAVE_ARCH_VMAP_STACK
158 select HAVE_ASM_MODVERSIONS
159 select HAVE_CMPXCHG_DOUBLE
160 select HAVE_CMPXCHG_LOCAL
161 select HAVE_DEBUG_KMEMLEAK
162 select HAVE_DMA_CONTIGUOUS
163 select HAVE_DYNAMIC_FTRACE
164 select HAVE_DYNAMIC_FTRACE_WITH_ARGS
165 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
166 select HAVE_DYNAMIC_FTRACE_WITH_REGS
167 select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES
168 select HAVE_EFFICIENT_UNALIGNED_ACCESS
169 select HAVE_FAST_GUP
170 select HAVE_FENTRY
171 select HAVE_FTRACE_MCOUNT_RECORD
172 select HAVE_FUNCTION_ARG_ACCESS_API
173 select HAVE_FUNCTION_ERROR_INJECTION
174 select HAVE_FUNCTION_GRAPH_TRACER
175 select HAVE_FUNCTION_TRACER
176 select HAVE_GCC_PLUGINS
177 select HAVE_GENERIC_VDSO
178 select HAVE_IOREMAP_PROT if PCI
179 select HAVE_KERNEL_BZIP2
180 select HAVE_KERNEL_GZIP
181 select HAVE_KERNEL_LZ4
182 select HAVE_KERNEL_LZMA
183 select HAVE_KERNEL_LZO
184 select HAVE_KERNEL_UNCOMPRESSED
185 select HAVE_KERNEL_XZ
186 select HAVE_KERNEL_ZSTD
187 select HAVE_KPROBES
188 select HAVE_KPROBES_ON_FTRACE
189 select HAVE_KRETPROBES
190 select HAVE_KVM
191 select HAVE_LIVEPATCH
192 select HAVE_MEMBLOCK_PHYS_MAP
193 select HAVE_MOD_ARCH_SPECIFIC
194 select HAVE_NMI
195 select HAVE_NOP_MCOUNT
196 select HAVE_PCI
197 select HAVE_PERF_EVENTS
198 select HAVE_PERF_REGS
199 select HAVE_PERF_USER_STACK_DUMP
200 select HAVE_REGS_AND_STACK_ACCESS_API
201 select HAVE_RELIABLE_STACKTRACE
202 select HAVE_RSEQ
203 select HAVE_SAMPLE_FTRACE_DIRECT
204 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
205 select HAVE_SETUP_PER_CPU_AREA
206 select HAVE_SOFTIRQ_ON_OWN_STACK
207 select HAVE_SYSCALL_TRACEPOINTS
208 select HAVE_VIRT_CPU_ACCOUNTING
209 select HAVE_VIRT_CPU_ACCOUNTING_IDLE
210 select IOMMU_HELPER if PCI
211 select IOMMU_SUPPORT if PCI
212 select MMU_GATHER_NO_GATHER
213 select MMU_GATHER_RCU_TABLE_FREE
214 select MMU_GATHER_MERGE_VMAS
215 select MODULES_USE_ELF_RELA
216 select NEED_DMA_MAP_STATE if PCI
217 select NEED_PER_CPU_EMBED_FIRST_CHUNK
218 select NEED_SG_DMA_LENGTH if PCI
219 select OLD_SIGACTION
220 select OLD_SIGSUSPEND3
221 select PCI_DOMAINS if PCI
222 select PCI_MSI if PCI
223 select PCI_MSI_ARCH_FALLBACKS if PCI_MSI
224 select SPARSE_IRQ
225 select SWIOTLB
226 select SYSCTL_EXCEPTION_TRACE
227 select THREAD_INFO_IN_TASK
228 select TRACE_IRQFLAGS_SUPPORT
229 select TTY
230 select VIRT_CPU_ACCOUNTING
231 select ZONE_DMA
232 # Note: keep the above list sorted alphabetically
233
234config SCHED_OMIT_FRAME_POINTER
235 def_bool y
236
237config PGTABLE_LEVELS
238 int
239 default 5
240
241source "kernel/livepatch/Kconfig"
242
243menu "Processor type and features"
244
245config HAVE_MARCH_Z10_FEATURES
246 def_bool n
247
248config HAVE_MARCH_Z196_FEATURES
249 def_bool n
250 select HAVE_MARCH_Z10_FEATURES
251
252config HAVE_MARCH_ZEC12_FEATURES
253 def_bool n
254 select HAVE_MARCH_Z196_FEATURES
255
256config HAVE_MARCH_Z13_FEATURES
257 def_bool n
258 select HAVE_MARCH_ZEC12_FEATURES
259
260config HAVE_MARCH_Z14_FEATURES
261 def_bool n
262 select HAVE_MARCH_Z13_FEATURES
263
264config HAVE_MARCH_Z15_FEATURES
265 def_bool n
266 select HAVE_MARCH_Z14_FEATURES
267
268config HAVE_MARCH_Z16_FEATURES
269 def_bool n
270 select HAVE_MARCH_Z15_FEATURES
271
272choice
273 prompt "Processor type"
274 default MARCH_Z196
275
276config MARCH_Z10
277 bool "IBM System z10"
278 select HAVE_MARCH_Z10_FEATURES
279 depends on $(cc-option,-march=z10)
280 help
281 Select this to enable optimizations for IBM System z10 (2097 and 2098
282 series). This is the oldest machine generation currently supported.
283
284config MARCH_Z196
285 bool "IBM zEnterprise 114 and 196"
286 select HAVE_MARCH_Z196_FEATURES
287 depends on $(cc-option,-march=z196)
288 help
289 Select this to enable optimizations for IBM zEnterprise 114 and 196
290 (2818 and 2817 series). The kernel will be slightly faster but will
291 not work on older machines.
292
293config MARCH_ZEC12
294 bool "IBM zBC12 and zEC12"
295 select HAVE_MARCH_ZEC12_FEATURES
296 depends on $(cc-option,-march=zEC12)
297 help
298 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
299 2827 series). The kernel will be slightly faster but will not work on
300 older machines.
301
302config MARCH_Z13
303 bool "IBM z13s and z13"
304 select HAVE_MARCH_Z13_FEATURES
305 depends on $(cc-option,-march=z13)
306 help
307 Select this to enable optimizations for IBM z13s and z13 (2965 and
308 2964 series). The kernel will be slightly faster but will not work on
309 older machines.
310
311config MARCH_Z14
312 bool "IBM z14 ZR1 and z14"
313 select HAVE_MARCH_Z14_FEATURES
314 depends on $(cc-option,-march=z14)
315 help
316 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
317 and 3906 series). The kernel will be slightly faster but will not
318 work on older machines.
319
320config MARCH_Z15
321 bool "IBM z15"
322 select HAVE_MARCH_Z15_FEATURES
323 depends on $(cc-option,-march=z15)
324 help
325 Select this to enable optimizations for IBM z15 (8562
326 and 8561 series). The kernel will be slightly faster but will not
327 work on older machines.
328
329config MARCH_Z16
330 bool "IBM z16"
331 select HAVE_MARCH_Z16_FEATURES
332 depends on $(cc-option,-march=z16)
333 help
334 Select this to enable optimizations for IBM z16 (3931 and
335 3932 series).
336
337endchoice
338
339config MARCH_Z10_TUNE
340 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
341
342config MARCH_Z196_TUNE
343 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
344
345config MARCH_ZEC12_TUNE
346 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
347
348config MARCH_Z13_TUNE
349 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
350
351config MARCH_Z14_TUNE
352 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
353
354config MARCH_Z15_TUNE
355 def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT
356
357config MARCH_Z16_TUNE
358 def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT
359
360choice
361 prompt "Tune code generation"
362 default TUNE_DEFAULT
363 help
364 Cause the compiler to tune (-mtune) the generated code for a machine.
365 This will make the code run faster on the selected machine but
366 somewhat slower on other machines.
367 This option only changes how the compiler emits instructions, not the
368 selection of instructions itself, so the resulting kernel will run on
369 all other machines.
370
371config TUNE_DEFAULT
372 bool "Default"
373 help
374 Tune the generated code for the target processor for which the kernel
375 will be compiled.
376
377config TUNE_Z10
378 bool "IBM System z10"
379
380config TUNE_Z196
381 bool "IBM zEnterprise 114 and 196"
382 depends on $(cc-option,-mtune=z196)
383
384config TUNE_ZEC12
385 bool "IBM zBC12 and zEC12"
386 depends on $(cc-option,-mtune=zEC12)
387
388config TUNE_Z13
389 bool "IBM z13s and z13"
390 depends on $(cc-option,-mtune=z13)
391
392config TUNE_Z14
393 bool "IBM z14 ZR1 and z14"
394 depends on $(cc-option,-mtune=z14)
395
396config TUNE_Z15
397 bool "IBM z15"
398 depends on $(cc-option,-mtune=z15)
399
400config TUNE_Z16
401 bool "IBM z16"
402 depends on $(cc-option,-mtune=z16)
403
404endchoice
405
406config 64BIT
407 def_bool y
408
409config COMMAND_LINE_SIZE
410 int "Maximum size of kernel command line"
411 default 4096
412 range 896 1048576
413 help
414 This allows you to specify the maximum length of the kernel command
415 line.
416
417config COMPAT
418 def_bool y
419 prompt "Kernel support for 31 bit emulation"
420 select ARCH_WANT_OLD_COMPAT_IPC
421 select COMPAT_OLD_SIGACTION
422 select HAVE_UID16
423 depends on MULTIUSER
424 depends on !CC_IS_CLANG
425 help
426 Select this option if you want to enable your system kernel to
427 handle system-calls from ELF binaries for 31 bit ESA. This option
428 (and some other stuff like libraries and such) is needed for
429 executing 31 bit applications. It is safe to say "Y".
430
431config SMP
432 def_bool y
433
434config NR_CPUS
435 int "Maximum number of CPUs (2-512)"
436 range 2 512
437 default "64"
438 help
439 This allows you to specify the maximum number of CPUs which this
440 kernel will support. The maximum supported value is 512 and the
441 minimum value which makes sense is 2.
442
443 This is purely to save memory - each supported CPU adds
444 approximately sixteen kilobytes to the kernel image.
445
446config HOTPLUG_CPU
447 def_bool y
448
449config NUMA
450 bool "NUMA support"
451 depends on SCHED_TOPOLOGY
452 default n
453 help
454 Enable NUMA support
455
456 This option adds NUMA support to the kernel.
457
458config NODES_SHIFT
459 int
460 depends on NUMA
461 default "1"
462
463config SCHED_SMT
464 def_bool n
465
466config SCHED_MC
467 def_bool n
468
469config SCHED_BOOK
470 def_bool n
471
472config SCHED_DRAWER
473 def_bool n
474
475config SCHED_TOPOLOGY
476 def_bool y
477 prompt "Topology scheduler support"
478 select SCHED_SMT
479 select SCHED_MC
480 select SCHED_BOOK
481 select SCHED_DRAWER
482 help
483 Topology scheduler support improves the CPU scheduler's decision
484 making when dealing with machines that have multi-threading,
485 multiple cores or multiple books.
486
487source "kernel/Kconfig.hz"
488
489config KEXEC
490 def_bool y
491 select KEXEC_CORE
492
493config KEXEC_FILE
494 bool "kexec file based system call"
495 select KEXEC_CORE
496 depends on CRYPTO
497 depends on CRYPTO_SHA256
498 depends on CRYPTO_SHA256_S390
499 help
500 Enable the kexec file based system call. In contrast to the normal
501 kexec system call this system call takes file descriptors for the
502 kernel and initramfs as arguments.
503
504config ARCH_HAS_KEXEC_PURGATORY
505 def_bool y
506 depends on KEXEC_FILE
507
508config KEXEC_SIG
509 bool "Verify kernel signature during kexec_file_load() syscall"
510 depends on KEXEC_FILE && MODULE_SIG_FORMAT
511 help
512 This option makes kernel signature verification mandatory for
513 the kexec_file_load() syscall.
514
515 In addition to that option, you need to enable signature
516 verification for the corresponding kernel image type being
517 loaded in order for this to work.
518
519config KERNEL_NOBP
520 def_bool n
521 prompt "Enable modified branch prediction for the kernel by default"
522 help
523 If this option is selected the kernel will switch to a modified
524 branch prediction mode if the firmware interface is available.
525 The modified branch prediction mode improves the behaviour in
526 regard to speculative execution.
527
528 With the option enabled the kernel parameter "nobp=0" or "nospec"
529 can be used to run the kernel in the normal branch prediction mode.
530
531 With the option disabled the modified branch prediction mode is
532 enabled with the "nobp=1" kernel parameter.
533
534 If unsure, say N.
535
536config EXPOLINE
537 def_bool n
538 depends on $(cc-option,-mindirect-branch=thunk)
539 prompt "Avoid speculative indirect branches in the kernel"
540 help
541 Compile the kernel with the expoline compiler options to guard
542 against kernel-to-user data leaks by avoiding speculative indirect
543 branches.
544 Requires a compiler with -mindirect-branch=thunk support for full
545 protection. The kernel may run slower.
546
547 If unsure, say N.
548
549config EXPOLINE_EXTERN
550 def_bool n
551 depends on EXPOLINE
552 depends on CC_IS_GCC && GCC_VERSION >= 110200
553 depends on $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC))
554 prompt "Generate expolines as extern functions."
555 help
556 This option is required for some tooling like kpatch. The kernel is
557 compiled with -mindirect-branch=thunk-extern and requires a newer
558 compiler.
559
560 If unsure, say N.
561
562choice
563 prompt "Expoline default"
564 depends on EXPOLINE
565 default EXPOLINE_FULL
566
567config EXPOLINE_OFF
568 bool "spectre_v2=off"
569
570config EXPOLINE_AUTO
571 bool "spectre_v2=auto"
572
573config EXPOLINE_FULL
574 bool "spectre_v2=on"
575
576endchoice
577
578config RELOCATABLE
579 def_bool y
580 help
581 This builds a kernel image that retains relocation information
582 so it can be loaded at an arbitrary address.
583 The kernel is linked as a position-independent executable (PIE)
584 and contains dynamic relocations which are processed early in the
585 bootup process.
586 The relocations make the kernel image about 15% larger (compressed
587 10%), but are discarded at runtime.
588 Note: this option exists only for documentation purposes, please do
589 not remove it.
590
591config RANDOMIZE_BASE
592 bool "Randomize the address of the kernel image (KASLR)"
593 default y
594 help
595 In support of Kernel Address Space Layout Randomization (KASLR),
596 this randomizes the address at which the kernel image is loaded,
597 as a security feature that deters exploit attempts relying on
598 knowledge of the location of kernel internals.
599
600endmenu
601
602menu "Memory setup"
603
604config ARCH_SPARSEMEM_ENABLE
605 def_bool y
606 select SPARSEMEM_VMEMMAP_ENABLE
607 select SPARSEMEM_VMEMMAP
608
609config ARCH_SPARSEMEM_DEFAULT
610 def_bool y
611
612config MAX_PHYSMEM_BITS
613 int "Maximum size of supported physical memory in bits (42-53)"
614 range 42 53
615 default "46"
616 help
617 This option specifies the maximum supported size of physical memory
618 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
619 Increasing the number of bits also increases the kernel image size.
620 By default 46 bits (64TB) are supported.
621
622config CHECK_STACK
623 def_bool y
624 depends on !VMAP_STACK
625 prompt "Detect kernel stack overflow"
626 help
627 This option enables the compiler option -mstack-guard and
628 -mstack-size if they are available. If the compiler supports them
629 it will emit additional code to each function prolog to trigger
630 an illegal operation if the kernel stack is about to overflow.
631
632 Say N if you are unsure.
633
634config STACK_GUARD
635 int "Size of the guard area (128-1024)"
636 range 128 1024
637 depends on CHECK_STACK
638 default "256"
639 help
640 This allows you to specify the size of the guard area at the lower
641 end of the kernel stack. If the kernel stack points into the guard
642 area on function entry an illegal operation is triggered. The size
643 needs to be a power of 2. Please keep in mind that the size of an
644 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
645 The minimum size for the stack guard should be 256 for 31 bit and
646 512 for 64 bit.
647
648endmenu
649
650menu "I/O subsystem"
651
652config QDIO
653 def_tristate y
654 prompt "QDIO support"
655 help
656 This driver provides the Queued Direct I/O base support for
657 IBM System z.
658
659 To compile this driver as a module, choose M here: the
660 module will be called qdio.
661
662 If unsure, say Y.
663
664if PCI
665
666config PCI_NR_FUNCTIONS
667 int "Maximum number of PCI functions (1-4096)"
668 range 1 4096
669 default "512"
670 help
671 This allows you to specify the maximum number of PCI functions which
672 this kernel will support.
673
674endif # PCI
675
676config HAS_IOMEM
677 def_bool PCI
678
679config CHSC_SCH
680 def_tristate m
681 prompt "Support for CHSC subchannels"
682 help
683 This driver allows usage of CHSC subchannels. A CHSC subchannel
684 is usually present on LPAR only.
685 The driver creates a device /dev/chsc, which may be used to
686 obtain I/O configuration information about the machine and
687 to issue asynchronous chsc commands (DANGEROUS).
688 You will usually only want to use this interface on a special
689 LPAR designated for system management.
690
691 To compile this driver as a module, choose M here: the
692 module will be called chsc_sch.
693
694 If unsure, say N.
695
696config SCM_BUS
697 def_bool y
698 prompt "SCM bus driver"
699 help
700 Bus driver for Storage Class Memory.
701
702config EADM_SCH
703 def_tristate m
704 prompt "Support for EADM subchannels"
705 depends on SCM_BUS
706 help
707 This driver allows usage of EADM subchannels. EADM subchannels act
708 as a communication vehicle for SCM increments.
709
710 To compile this driver as a module, choose M here: the
711 module will be called eadm_sch.
712
713config VFIO_CCW
714 def_tristate n
715 prompt "Support for VFIO-CCW subchannels"
716 depends on S390_CCW_IOMMU && VFIO_MDEV
717 help
718 This driver allows usage of I/O subchannels via VFIO-CCW.
719
720 To compile this driver as a module, choose M here: the
721 module will be called vfio_ccw.
722
723config VFIO_AP
724 def_tristate n
725 prompt "VFIO support for AP devices"
726 depends on S390_AP_IOMMU && VFIO_MDEV && KVM
727 depends on ZCRYPT
728 help
729 This driver grants access to Adjunct Processor (AP) devices
730 via the VFIO mediated device interface.
731
732 To compile this driver as a module, choose M here: the module
733 will be called vfio_ap.
734
735endmenu
736
737menu "Dump support"
738
739config CRASH_DUMP
740 bool "kernel crash dumps"
741 select KEXEC
742 help
743 Generate crash dump after being started by kexec.
744 Crash dump kernels are loaded in the main kernel with kexec-tools
745 into a specially reserved region and then later executed after
746 a crash by kdump/kexec.
747 Refer to <file:Documentation/s390/zfcpdump.rst> for more details on this.
748 This option also enables s390 zfcpdump.
749 See also <file:Documentation/s390/zfcpdump.rst>
750
751endmenu
752
753config CCW
754 def_bool y
755
756config HAVE_PNETID
757 tristate
758 default (SMC || CCWGROUP)
759
760menu "Virtualization"
761
762config PROTECTED_VIRTUALIZATION_GUEST
763 def_bool n
764 prompt "Protected virtualization guest support"
765 help
766 Select this option, if you want to be able to run this
767 kernel as a protected virtualization KVM guest.
768 Protected virtualization capable machines have a mini hypervisor
769 located at machine level (an ultravisor). With help of the
770 Ultravisor, KVM will be able to run "protected" VMs, special
771 VMs whose memory and management data are unavailable to KVM.
772
773config PFAULT
774 def_bool y
775 prompt "Pseudo page fault support"
776 help
777 Select this option, if you want to use PFAULT pseudo page fault
778 handling under VM. If running native or in LPAR, this option
779 has no effect. If your VM does not support PFAULT, PAGEEX
780 pseudo page fault handling will be used.
781 Note that VM 4.2 supports PFAULT but has a bug in its
782 implementation that causes some problems.
783 Everybody who wants to run Linux under VM != VM4.2 should select
784 this option.
785
786config CMM
787 def_tristate n
788 prompt "Cooperative memory management"
789 help
790 Select this option, if you want to enable the kernel interface
791 to reduce the memory size of the system. This is accomplished
792 by allocating pages of memory and put them "on hold". This only
793 makes sense for a system running under VM where the unused pages
794 will be reused by VM for other guest systems. The interface
795 allows an external monitor to balance memory of many systems.
796 Everybody who wants to run Linux under VM should select this
797 option.
798
799config CMM_IUCV
800 def_bool y
801 prompt "IUCV special message interface to cooperative memory management"
802 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
803 help
804 Select this option to enable the special message interface to
805 the cooperative memory management.
806
807config APPLDATA_BASE
808 def_bool n
809 prompt "Linux - VM Monitor Stream, base infrastructure"
810 depends on PROC_SYSCTL
811 help
812 This provides a kernel interface for creating and updating z/VM APPLDATA
813 monitor records. The monitor records are updated at certain time
814 intervals, once the timer is started.
815 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
816 i.e. enables or disables monitoring on the Linux side.
817 A custom interval value (in seconds) can be written to
818 /proc/appldata/interval.
819
820 Defaults are 60 seconds interval and timer off.
821 The /proc entries can also be read from, showing the current settings.
822
823config APPLDATA_MEM
824 def_tristate m
825 prompt "Monitor memory management statistics"
826 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
827 help
828 This provides memory management related data to the Linux - VM Monitor
829 Stream, like paging/swapping rate, memory utilisation, etc.
830 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
831 APPLDATA monitor record, i.e. enables or disables monitoring this record
832 on the z/VM side.
833
834 Default is disabled.
835 The /proc entry can also be read from, showing the current settings.
836
837 This can also be compiled as a module, which will be called
838 appldata_mem.o.
839
840config APPLDATA_OS
841 def_tristate m
842 prompt "Monitor OS statistics"
843 depends on APPLDATA_BASE
844 help
845 This provides OS related data to the Linux - VM Monitor Stream, like
846 CPU utilisation, etc.
847 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
848 APPLDATA monitor record, i.e. enables or disables monitoring this record
849 on the z/VM side.
850
851 Default is disabled.
852 This can also be compiled as a module, which will be called
853 appldata_os.o.
854
855config APPLDATA_NET_SUM
856 def_tristate m
857 prompt "Monitor overall network statistics"
858 depends on APPLDATA_BASE && NET
859 help
860 This provides network related data to the Linux - VM Monitor Stream,
861 currently there is only a total sum of network I/O statistics, no
862 per-interface data.
863 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
864 APPLDATA monitor record, i.e. enables or disables monitoring this record
865 on the z/VM side.
866
867 Default is disabled.
868 This can also be compiled as a module, which will be called
869 appldata_net_sum.o.
870
871config S390_HYPFS_FS
872 def_bool y
873 prompt "s390 hypervisor file system support"
874 select SYS_HYPERVISOR
875 help
876 This is a virtual file system intended to provide accounting
877 information in an s390 hypervisor environment.
878
879source "arch/s390/kvm/Kconfig"
880
881config S390_GUEST
882 def_bool y
883 prompt "s390 support for virtio devices"
884 select TTY
885 select VIRTUALIZATION
886 select VIRTIO
887 help
888 Enabling this option adds support for virtio based paravirtual device
889 drivers on s390.
890
891 Select this option if you want to run the kernel as a guest under
892 the KVM hypervisor.
893
894endmenu
895
896config S390_MODULES_SANITY_TEST_HELPERS
897 def_bool n
898
899menu "Selftests"
900
901config S390_UNWIND_SELFTEST
902 def_tristate n
903 depends on KUNIT
904 default KUNIT_ALL_TESTS
905 prompt "Test unwind functions"
906 help
907 This option enables s390 specific stack unwinder testing kernel
908 module. This option is not useful for distributions or general
909 kernels, but only for kernel developers working on architecture code.
910
911 Say N if you are unsure.
912
913config S390_KPROBES_SANITY_TEST
914 def_tristate n
915 prompt "Enable s390 specific kprobes tests"
916 depends on KPROBES
917 depends on KUNIT
918 help
919 This option enables an s390 specific kprobes test module. This option
920 is not useful for distributions or general kernels, but only for kernel
921 developers working on architecture code.
922
923 Say N if you are unsure.
924
925config S390_MODULES_SANITY_TEST
926 def_tristate n
927 depends on KUNIT
928 default KUNIT_ALL_TESTS
929 prompt "Enable s390 specific modules tests"
930 select S390_MODULES_SANITY_TEST_HELPERS
931 help
932 This option enables an s390 specific modules test. This option is
933 not useful for distributions or general kernels, but only for
934 kernel developers working on architecture code.
935
936 Say N if you are unsure.
937endmenu
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 ARCH_DMA_ADDR_T_64BIT
39 def_bool y
40
41config GENERIC_LOCKBREAK
42 def_bool y if SMP && PREEMPT
43
44config PGSTE
45 def_bool y if KVM
46
47config ARCH_SUPPORTS_DEBUG_PAGEALLOC
48 def_bool y
49
50config AUDIT_ARCH
51 def_bool y
52
53config NO_IOPORT_MAP
54 def_bool y
55
56config PCI_QUIRKS
57 def_bool n
58
59config ARCH_SUPPORTS_UPROBES
60 def_bool y
61
62config S390
63 def_bool y
64 select ARCH_BINFMT_ELF_STATE
65 select ARCH_HAS_DEVMEM_IS_ALLOWED
66 select ARCH_HAS_ELF_RANDOMIZE
67 select ARCH_HAS_FORTIFY_SOURCE
68 select ARCH_HAS_GCOV_PROFILE_ALL
69 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
70 select ARCH_HAS_KCOV
71 select ARCH_HAS_SET_MEMORY
72 select ARCH_HAS_SG_CHAIN
73 select ARCH_HAS_STRICT_KERNEL_RWX
74 select ARCH_HAS_STRICT_MODULE_RWX
75 select ARCH_HAS_UBSAN_SANITIZE_ALL
76 select ARCH_HAVE_NMI_SAFE_CMPXCHG
77 select ARCH_INLINE_READ_LOCK
78 select ARCH_INLINE_READ_LOCK_BH
79 select ARCH_INLINE_READ_LOCK_IRQ
80 select ARCH_INLINE_READ_LOCK_IRQSAVE
81 select ARCH_INLINE_READ_TRYLOCK
82 select ARCH_INLINE_READ_UNLOCK
83 select ARCH_INLINE_READ_UNLOCK_BH
84 select ARCH_INLINE_READ_UNLOCK_IRQ
85 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
86 select ARCH_INLINE_SPIN_LOCK
87 select ARCH_INLINE_SPIN_LOCK_BH
88 select ARCH_INLINE_SPIN_LOCK_IRQ
89 select ARCH_INLINE_SPIN_LOCK_IRQSAVE
90 select ARCH_INLINE_SPIN_TRYLOCK
91 select ARCH_INLINE_SPIN_TRYLOCK_BH
92 select ARCH_INLINE_SPIN_UNLOCK
93 select ARCH_INLINE_SPIN_UNLOCK_BH
94 select ARCH_INLINE_SPIN_UNLOCK_IRQ
95 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
96 select ARCH_INLINE_WRITE_LOCK
97 select ARCH_INLINE_WRITE_LOCK_BH
98 select ARCH_INLINE_WRITE_LOCK_IRQ
99 select ARCH_INLINE_WRITE_LOCK_IRQSAVE
100 select ARCH_INLINE_WRITE_TRYLOCK
101 select ARCH_INLINE_WRITE_UNLOCK
102 select ARCH_INLINE_WRITE_UNLOCK_BH
103 select ARCH_INLINE_WRITE_UNLOCK_IRQ
104 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
105 select ARCH_SAVE_PAGE_KEYS if HIBERNATION
106 select ARCH_SUPPORTS_ATOMIC_RMW
107 select ARCH_SUPPORTS_NUMA_BALANCING
108 select ARCH_USE_BUILTIN_BSWAP
109 select ARCH_USE_CMPXCHG_LOCKREF
110 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
111 select ARCH_WANTS_UBSAN_NO_NULL
112 select ARCH_WANT_IPC_PARSE_VERSION
113 select BUILDTIME_EXTABLE_SORT
114 select CLONE_BACKWARDS2
115 select DYNAMIC_FTRACE if FUNCTION_TRACER
116 select GENERIC_CLOCKEVENTS
117 select GENERIC_CPU_AUTOPROBE
118 select GENERIC_CPU_DEVICES if !SMP
119 select GENERIC_CPU_VULNERABILITIES
120 select GENERIC_FIND_FIRST_BIT
121 select GENERIC_SMP_IDLE_THREAD
122 select GENERIC_TIME_VSYSCALL
123 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
124 select HAVE_ARCH_AUDITSYSCALL
125 select HAVE_ARCH_JUMP_LABEL
126 select CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES
127 select HAVE_ARCH_SECCOMP_FILTER
128 select HAVE_ARCH_SOFT_DIRTY
129 select HAVE_ARCH_TRACEHOOK
130 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
131 select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
132 select HAVE_CMPXCHG_DOUBLE
133 select HAVE_CMPXCHG_LOCAL
134 select HAVE_COPY_THREAD_TLS
135 select HAVE_DEBUG_KMEMLEAK
136 select HAVE_DMA_API_DEBUG
137 select HAVE_DMA_CONTIGUOUS
138 select DMA_DIRECT_OPS
139 select HAVE_DYNAMIC_FTRACE
140 select HAVE_DYNAMIC_FTRACE_WITH_REGS
141 select HAVE_EFFICIENT_UNALIGNED_ACCESS
142 select HAVE_FTRACE_MCOUNT_RECORD
143 select HAVE_FUNCTION_GRAPH_TRACER
144 select HAVE_FUNCTION_TRACER
145 select HAVE_FUTEX_CMPXCHG if FUTEX
146 select HAVE_GCC_PLUGINS
147 select HAVE_KERNEL_BZIP2
148 select HAVE_KERNEL_GZIP
149 select HAVE_KERNEL_LZ4
150 select HAVE_KERNEL_LZMA
151 select HAVE_KERNEL_LZO
152 select HAVE_KERNEL_XZ
153 select HAVE_KPROBES
154 select HAVE_KRETPROBES
155 select HAVE_KVM
156 select HAVE_LIVEPATCH
157 select HAVE_PERF_REGS
158 select HAVE_PERF_USER_STACK_DUMP
159 select HAVE_MEMBLOCK
160 select HAVE_MEMBLOCK_NODE_MAP
161 select HAVE_MEMBLOCK_PHYS_MAP
162 select HAVE_MOD_ARCH_SPECIFIC
163 select HAVE_OPROFILE
164 select HAVE_PERF_EVENTS
165 select HAVE_REGS_AND_STACK_ACCESS_API
166 select HAVE_SYSCALL_TRACEPOINTS
167 select HAVE_VIRT_CPU_ACCOUNTING
168 select MODULES_USE_ELF_RELA
169 select NO_BOOTMEM
170 select OLD_SIGACTION
171 select OLD_SIGSUSPEND3
172 select SPARSE_IRQ
173 select SYSCTL_EXCEPTION_TRACE
174 select THREAD_INFO_IN_TASK
175 select TTY
176 select VIRT_CPU_ACCOUNTING
177 select ARCH_HAS_SCALED_CPUTIME
178 select VIRT_TO_BUS
179 select HAVE_NMI
180
181
182config SCHED_OMIT_FRAME_POINTER
183 def_bool y
184
185config PGTABLE_LEVELS
186 int
187 default 5
188
189source "init/Kconfig"
190
191source "kernel/Kconfig.freezer"
192
193source "kernel/livepatch/Kconfig"
194
195menu "Processor type and features"
196
197config HAVE_MARCH_Z900_FEATURES
198 def_bool n
199
200config HAVE_MARCH_Z990_FEATURES
201 def_bool n
202 select HAVE_MARCH_Z900_FEATURES
203
204config HAVE_MARCH_Z9_109_FEATURES
205 def_bool n
206 select HAVE_MARCH_Z990_FEATURES
207
208config HAVE_MARCH_Z10_FEATURES
209 def_bool n
210 select HAVE_MARCH_Z9_109_FEATURES
211
212config HAVE_MARCH_Z196_FEATURES
213 def_bool n
214 select HAVE_MARCH_Z10_FEATURES
215
216config HAVE_MARCH_ZEC12_FEATURES
217 def_bool n
218 select HAVE_MARCH_Z196_FEATURES
219
220config HAVE_MARCH_Z13_FEATURES
221 def_bool n
222 select HAVE_MARCH_ZEC12_FEATURES
223
224config HAVE_MARCH_Z14_FEATURES
225 def_bool n
226 select HAVE_MARCH_Z13_FEATURES
227
228choice
229 prompt "Processor type"
230 default MARCH_Z196
231
232config MARCH_Z900
233 bool "IBM zSeries model z800 and z900"
234 select HAVE_MARCH_Z900_FEATURES
235 help
236 Select this to enable optimizations for model z800/z900 (2064 and
237 2066 series). This will enable some optimizations that are not
238 available on older ESA/390 (31 Bit) only CPUs.
239
240config MARCH_Z990
241 bool "IBM zSeries model z890 and z990"
242 select HAVE_MARCH_Z990_FEATURES
243 help
244 Select this to enable optimizations for model z890/z990 (2084 and
245 2086 series). The kernel will be slightly faster but will not work
246 on older machines.
247
248config MARCH_Z9_109
249 bool "IBM System z9"
250 select HAVE_MARCH_Z9_109_FEATURES
251 help
252 Select this to enable optimizations for IBM System z9 (2094 and
253 2096 series). The kernel will be slightly faster but will not work
254 on older machines.
255
256config MARCH_Z10
257 bool "IBM System z10"
258 select HAVE_MARCH_Z10_FEATURES
259 help
260 Select this to enable optimizations for IBM System z10 (2097 and
261 2098 series). The kernel will be slightly faster but will not work
262 on older machines.
263
264config MARCH_Z196
265 bool "IBM zEnterprise 114 and 196"
266 select HAVE_MARCH_Z196_FEATURES
267 help
268 Select this to enable optimizations for IBM zEnterprise 114 and 196
269 (2818 and 2817 series). The kernel will be slightly faster but will
270 not work on older machines.
271
272config MARCH_ZEC12
273 bool "IBM zBC12 and zEC12"
274 select HAVE_MARCH_ZEC12_FEATURES
275 help
276 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
277 2827 series). The kernel will be slightly faster but will not work on
278 older machines.
279
280config MARCH_Z13
281 bool "IBM z13s and z13"
282 select HAVE_MARCH_Z13_FEATURES
283 help
284 Select this to enable optimizations for IBM z13s and z13 (2965 and
285 2964 series). The kernel will be slightly faster but will not work on
286 older machines.
287
288config MARCH_Z14
289 bool "IBM z14 ZR1 and z14"
290 select HAVE_MARCH_Z14_FEATURES
291 help
292 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
293 and 3906 series). The kernel will be slightly faster but will not
294 work on older machines.
295
296endchoice
297
298config MARCH_Z900_TUNE
299 def_bool TUNE_Z900 || MARCH_Z900 && TUNE_DEFAULT
300
301config MARCH_Z990_TUNE
302 def_bool TUNE_Z990 || MARCH_Z990 && TUNE_DEFAULT
303
304config MARCH_Z9_109_TUNE
305 def_bool TUNE_Z9_109 || MARCH_Z9_109 && TUNE_DEFAULT
306
307config MARCH_Z10_TUNE
308 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
309
310config MARCH_Z196_TUNE
311 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
312
313config MARCH_ZEC12_TUNE
314 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
315
316config MARCH_Z13_TUNE
317 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
318
319config MARCH_Z14_TUNE
320 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
321
322choice
323 prompt "Tune code generation"
324 default TUNE_DEFAULT
325 help
326 Cause the compiler to tune (-mtune) the generated code for a machine.
327 This will make the code run faster on the selected machine but
328 somewhat slower on other machines.
329 This option only changes how the compiler emits instructions, not the
330 selection of instructions itself, so the resulting kernel will run on
331 all other machines.
332
333config TUNE_DEFAULT
334 bool "Default"
335 help
336 Tune the generated code for the target processor for which the kernel
337 will be compiled.
338
339config TUNE_Z900
340 bool "IBM zSeries model z800 and z900"
341
342config TUNE_Z990
343 bool "IBM zSeries model z890 and z990"
344
345config TUNE_Z9_109
346 bool "IBM System z9"
347
348config TUNE_Z10
349 bool "IBM System z10"
350
351config TUNE_Z196
352 bool "IBM zEnterprise 114 and 196"
353
354config TUNE_ZEC12
355 bool "IBM zBC12 and zEC12"
356
357config TUNE_Z13
358 bool "IBM z13"
359
360config TUNE_Z14
361 bool "IBM z14"
362
363endchoice
364
365config 64BIT
366 def_bool y
367
368config COMPAT
369 def_bool y
370 prompt "Kernel support for 31 bit emulation"
371 select COMPAT_BINFMT_ELF if BINFMT_ELF
372 select ARCH_WANT_OLD_COMPAT_IPC
373 select COMPAT_OLD_SIGACTION
374 depends on MULTIUSER
375 help
376 Select this option if you want to enable your system kernel to
377 handle system-calls from ELF binaries for 31 bit ESA. This option
378 (and some other stuff like libraries and such) is needed for
379 executing 31 bit applications. It is safe to say "Y".
380
381config SYSVIPC_COMPAT
382 def_bool y if COMPAT && SYSVIPC
383
384config SMP
385 def_bool y
386 prompt "Symmetric multi-processing support"
387 ---help---
388 This enables support for systems with more than one CPU. If you have
389 a system with only one CPU, like most personal computers, say N. If
390 you have a system with more than one CPU, say Y.
391
392 If you say N here, the kernel will run on uni- and multiprocessor
393 machines, but will use only one CPU of a multiprocessor machine. If
394 you say Y here, the kernel will run on many, but not all,
395 uniprocessor machines. On a uniprocessor machine, the kernel
396 will run faster if you say N here.
397
398 See also the SMP-HOWTO available at
399 <http://www.tldp.org/docs.html#howto>.
400
401 Even if you don't know what to do here, say Y.
402
403config NR_CPUS
404 int "Maximum number of CPUs (2-512)"
405 range 2 512
406 depends on SMP
407 default "64"
408 help
409 This allows you to specify the maximum number of CPUs which this
410 kernel will support. The maximum supported value is 512 and the
411 minimum value which makes sense is 2.
412
413 This is purely to save memory - each supported CPU adds
414 approximately sixteen kilobytes to the kernel image.
415
416config HOTPLUG_CPU
417 def_bool y
418 prompt "Support for hot-pluggable CPUs"
419 depends on SMP
420 help
421 Say Y here to be able to turn CPUs off and on. CPUs
422 can be controlled through /sys/devices/system/cpu/cpu#.
423 Say N if you want to disable CPU hotplug.
424
425# Some NUMA nodes have memory ranges that span
426# other nodes. Even though a pfn is valid and
427# between a node's start and end pfns, it may not
428# reside on that node. See memmap_init_zone()
429# for details. <- They meant memory holes!
430config NODES_SPAN_OTHER_NODES
431 def_bool NUMA
432
433config NUMA
434 bool "NUMA support"
435 depends on SMP && SCHED_TOPOLOGY
436 default n
437 help
438 Enable NUMA support
439
440 This option adds NUMA support to the kernel.
441
442 An operation mode can be selected by appending
443 numa=<method> to the kernel command line.
444
445 The default behaviour is identical to appending numa=plain to
446 the command line. This will create just one node with all
447 available memory and all CPUs in it.
448
449config NODES_SHIFT
450 int "Maximum NUMA nodes (as a power of 2)"
451 range 1 10
452 depends on NUMA
453 default "4"
454 help
455 Specify the maximum number of NUMA nodes available on the target
456 system. Increases memory reserved to accommodate various tables.
457
458menu "Select NUMA modes"
459 depends on NUMA
460
461config NUMA_EMU
462 bool "NUMA emulation"
463 default y
464 help
465 Numa emulation mode will split the available system memory into
466 equal chunks which then are distributed over the configured number
467 of nodes in a round-robin manner.
468
469 The number of fake nodes is limited by the number of available memory
470 chunks (i.e. memory size / fake size) and the number of supported
471 nodes in the kernel.
472
473 The CPUs are assigned to the nodes in a way that partially respects
474 the original machine topology (if supported by the machine).
475 Fair distribution of the CPUs is not guaranteed.
476
477config EMU_SIZE
478 hex "NUMA emulation memory chunk size"
479 default 0x10000000
480 range 0x400000 0x100000000
481 depends on NUMA_EMU
482 help
483 Select the default size by which the memory is chopped and then
484 assigned to emulated NUMA nodes.
485
486 This can be overridden by specifying
487
488 emu_size=<n>
489
490 on the kernel command line where also suffixes K, M, G, and T are
491 supported.
492
493endmenu
494
495config SCHED_SMT
496 def_bool n
497
498config SCHED_MC
499 def_bool n
500
501config SCHED_BOOK
502 def_bool n
503
504config SCHED_DRAWER
505 def_bool n
506
507config SCHED_TOPOLOGY
508 def_bool y
509 prompt "Topology scheduler support"
510 depends on SMP
511 select SCHED_SMT
512 select SCHED_MC
513 select SCHED_BOOK
514 select SCHED_DRAWER
515 help
516 Topology scheduler support improves the CPU scheduler's decision
517 making when dealing with machines that have multi-threading,
518 multiple cores or multiple books.
519
520source kernel/Kconfig.preempt
521
522source kernel/Kconfig.hz
523
524config KEXEC
525 def_bool y
526 select KEXEC_CORE
527
528config KEXEC_FILE
529 bool "kexec file based system call"
530 select KEXEC_CORE
531 select BUILD_BIN2C
532 depends on CRYPTO
533 depends on CRYPTO_SHA256
534 depends on CRYPTO_SHA256_S390
535 help
536 Enable the kexec file based system call. In contrast to the normal
537 kexec system call this system call takes file descriptors for the
538 kernel and initramfs as arguments.
539
540config ARCH_HAS_KEXEC_PURGATORY
541 def_bool y
542 depends on KEXEC_FILE
543
544config ARCH_RANDOM
545 def_bool y
546 prompt "s390 architectural random number generation API"
547 help
548 Enable the s390 architectural random number generation API
549 to provide random data for all consumers within the Linux
550 kernel.
551
552 When enabled the arch_random_* functions declared in linux/random.h
553 are implemented. The implementation is based on the s390 CPACF
554 instruction subfunction TRNG which provides a real true random
555 number generator.
556
557 If unsure, say Y.
558
559config KERNEL_NOBP
560 def_bool n
561 prompt "Enable modified branch prediction for the kernel by default"
562 help
563 If this option is selected the kernel will switch to a modified
564 branch prediction mode if the firmware interface is available.
565 The modified branch prediction mode improves the behaviour in
566 regard to speculative execution.
567
568 With the option enabled the kernel parameter "nobp=0" or "nospec"
569 can be used to run the kernel in the normal branch prediction mode.
570
571 With the option disabled the modified branch prediction mode is
572 enabled with the "nobp=1" kernel parameter.
573
574 If unsure, say N.
575
576config EXPOLINE
577 def_bool n
578 prompt "Avoid speculative indirect branches in the kernel"
579 help
580 Compile the kernel with the expoline compiler options to guard
581 against kernel-to-user data leaks by avoiding speculative indirect
582 branches.
583 Requires a compiler with -mindirect-branch=thunk support for full
584 protection. The kernel may run slower.
585
586 If unsure, say N.
587
588choice
589 prompt "Expoline default"
590 depends on EXPOLINE
591 default EXPOLINE_FULL
592
593config EXPOLINE_OFF
594 bool "spectre_v2=off"
595
596config EXPOLINE_AUTO
597 bool "spectre_v2=auto"
598
599config EXPOLINE_FULL
600 bool "spectre_v2=on"
601
602endchoice
603
604endmenu
605
606menu "Memory setup"
607
608config ARCH_SPARSEMEM_ENABLE
609 def_bool y
610 select SPARSEMEM_VMEMMAP_ENABLE
611 select SPARSEMEM_VMEMMAP
612
613config ARCH_SPARSEMEM_DEFAULT
614 def_bool y
615
616config ARCH_SELECT_MEMORY_MODEL
617 def_bool y
618
619config ARCH_ENABLE_MEMORY_HOTPLUG
620 def_bool y if SPARSEMEM
621
622config ARCH_ENABLE_MEMORY_HOTREMOVE
623 def_bool y
624
625config ARCH_ENABLE_SPLIT_PMD_PTLOCK
626 def_bool y
627
628config FORCE_MAX_ZONEORDER
629 int
630 default "9"
631
632source "mm/Kconfig"
633
634config MAX_PHYSMEM_BITS
635 int "Maximum size of supported physical memory in bits (42-53)"
636 range 42 53
637 default "46"
638 help
639 This option specifies the maximum supported size of physical memory
640 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
641 Increasing the number of bits also increases the kernel image size.
642 By default 46 bits (64TB) are supported.
643
644config PACK_STACK
645 def_bool y
646 prompt "Pack kernel stack"
647 help
648 This option enables the compiler option -mkernel-backchain if it
649 is available. If the option is available the compiler supports
650 the new stack layout which dramatically reduces the minimum stack
651 frame size. With an old compiler a non-leaf function needs a
652 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
653 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
654 and 24 byte on 64 bit.
655
656 Say Y if you are unsure.
657
658config CHECK_STACK
659 def_bool y
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_SUPPORT
713 help
714 Enable PCI support.
715
716if PCI
717
718config PCI_NR_FUNCTIONS
719 int "Maximum number of PCI functions (1-4096)"
720 range 1 4096
721 default "128"
722 help
723 This allows you to specify the maximum number of PCI functions which
724 this kernel will support.
725
726source "drivers/pci/Kconfig"
727
728endif # PCI
729
730config PCI_DOMAINS
731 def_bool PCI
732
733config HAS_IOMEM
734 def_bool PCI
735
736config IOMMU_HELPER
737 def_bool PCI
738
739config NEED_SG_DMA_LENGTH
740 def_bool PCI
741
742config NEED_DMA_MAP_STATE
743 def_bool PCI
744
745config CHSC_SCH
746 def_tristate m
747 prompt "Support for CHSC subchannels"
748 help
749 This driver allows usage of CHSC subchannels. A CHSC subchannel
750 is usually present on LPAR only.
751 The driver creates a device /dev/chsc, which may be used to
752 obtain I/O configuration information about the machine and
753 to issue asynchronous chsc commands (DANGEROUS).
754 You will usually only want to use this interface on a special
755 LPAR designated for system management.
756
757 To compile this driver as a module, choose M here: the
758 module will be called chsc_sch.
759
760 If unsure, say N.
761
762config SCM_BUS
763 def_bool y
764 prompt "SCM bus driver"
765 help
766 Bus driver for Storage Class Memory.
767
768config EADM_SCH
769 def_tristate m
770 prompt "Support for EADM subchannels"
771 depends on SCM_BUS
772 help
773 This driver allows usage of EADM subchannels. EADM subchannels act
774 as a communication vehicle for SCM increments.
775
776 To compile this driver as a module, choose M here: the
777 module will be called eadm_sch.
778
779config VFIO_CCW
780 def_tristate n
781 prompt "Support for VFIO-CCW subchannels"
782 depends on S390_CCW_IOMMU && VFIO_MDEV
783 help
784 This driver allows usage of I/O subchannels via VFIO-CCW.
785
786 To compile this driver as a module, choose M here: the
787 module will be called vfio_ccw.
788
789endmenu
790
791menu "Dump support"
792
793config CRASH_DUMP
794 bool "kernel crash dumps"
795 depends on SMP
796 select KEXEC
797 help
798 Generate crash dump after being started by kexec.
799 Crash dump kernels are loaded in the main kernel with kexec-tools
800 into a specially reserved region and then later executed after
801 a crash by kdump/kexec.
802 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
803 This option also enables s390 zfcpdump.
804 See also <file:Documentation/s390/zfcpdump.txt>
805
806endmenu
807
808menu "Executable file formats / Emulations"
809
810source "fs/Kconfig.binfmt"
811
812config SECCOMP
813 def_bool y
814 prompt "Enable seccomp to safely compute untrusted bytecode"
815 depends on PROC_FS
816 help
817 This kernel feature is useful for number crunching applications
818 that may need to compute untrusted bytecode during their
819 execution. By using pipes or other transports made available to
820 the process as file descriptors supporting the read/write
821 syscalls, it's possible to isolate those applications in
822 their own address space using seccomp. Once seccomp is
823 enabled via /proc/<pid>/seccomp, it cannot be disabled
824 and the task is only allowed to execute a few safe syscalls
825 defined by each seccomp mode.
826
827 If unsure, say Y.
828
829endmenu
830
831menu "Power Management"
832
833config ARCH_HIBERNATION_POSSIBLE
834 def_bool y
835
836source "kernel/power/Kconfig"
837
838endmenu
839
840source "net/Kconfig"
841
842config PCMCIA
843 def_bool n
844
845config CCW
846 def_bool y
847
848source "drivers/Kconfig"
849
850source "fs/Kconfig"
851
852source "arch/s390/Kconfig.debug"
853
854source "security/Kconfig"
855
856source "crypto/Kconfig"
857
858source "lib/Kconfig"
859
860menu "Virtualization"
861
862config PFAULT
863 def_bool y
864 prompt "Pseudo page fault support"
865 help
866 Select this option, if you want to use PFAULT pseudo page fault
867 handling under VM. If running native or in LPAR, this option
868 has no effect. If your VM does not support PFAULT, PAGEEX
869 pseudo page fault handling will be used.
870 Note that VM 4.2 supports PFAULT but has a bug in its
871 implementation that causes some problems.
872 Everybody who wants to run Linux under VM != VM4.2 should select
873 this option.
874
875config CMM
876 def_tristate n
877 prompt "Cooperative memory management"
878 help
879 Select this option, if you want to enable the kernel interface
880 to reduce the memory size of the system. This is accomplished
881 by allocating pages of memory and put them "on hold". This only
882 makes sense for a system running under VM where the unused pages
883 will be reused by VM for other guest systems. The interface
884 allows an external monitor to balance memory of many systems.
885 Everybody who wants to run Linux under VM should select this
886 option.
887
888config CMM_IUCV
889 def_bool y
890 prompt "IUCV special message interface to cooperative memory management"
891 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
892 help
893 Select this option to enable the special message interface to
894 the cooperative memory management.
895
896config APPLDATA_BASE
897 def_bool n
898 prompt "Linux - VM Monitor Stream, base infrastructure"
899 depends on PROC_FS
900 help
901 This provides a kernel interface for creating and updating z/VM APPLDATA
902 monitor records. The monitor records are updated at certain time
903 intervals, once the timer is started.
904 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
905 i.e. enables or disables monitoring on the Linux side.
906 A custom interval value (in seconds) can be written to
907 /proc/appldata/interval.
908
909 Defaults are 60 seconds interval and timer off.
910 The /proc entries can also be read from, showing the current settings.
911
912config APPLDATA_MEM
913 def_tristate m
914 prompt "Monitor memory management statistics"
915 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
916 help
917 This provides memory management related data to the Linux - VM Monitor
918 Stream, like paging/swapping rate, memory utilisation, etc.
919 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
920 APPLDATA monitor record, i.e. enables or disables monitoring this record
921 on the z/VM side.
922
923 Default is disabled.
924 The /proc entry can also be read from, showing the current settings.
925
926 This can also be compiled as a module, which will be called
927 appldata_mem.o.
928
929config APPLDATA_OS
930 def_tristate m
931 prompt "Monitor OS statistics"
932 depends on APPLDATA_BASE
933 help
934 This provides OS related data to the Linux - VM Monitor Stream, like
935 CPU utilisation, etc.
936 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
937 APPLDATA monitor record, i.e. enables or disables monitoring this record
938 on the z/VM side.
939
940 Default is disabled.
941 This can also be compiled as a module, which will be called
942 appldata_os.o.
943
944config APPLDATA_NET_SUM
945 def_tristate m
946 prompt "Monitor overall network statistics"
947 depends on APPLDATA_BASE && NET
948 help
949 This provides network related data to the Linux - VM Monitor Stream,
950 currently there is only a total sum of network I/O statistics, no
951 per-interface data.
952 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
953 APPLDATA monitor record, i.e. enables or disables monitoring this record
954 on the z/VM side.
955
956 Default is disabled.
957 This can also be compiled as a module, which will be called
958 appldata_net_sum.o.
959
960config S390_HYPFS_FS
961 def_bool y
962 prompt "s390 hypervisor file system support"
963 select SYS_HYPERVISOR
964 help
965 This is a virtual file system intended to provide accounting
966 information in an s390 hypervisor environment.
967
968source "arch/s390/kvm/Kconfig"
969
970config S390_GUEST
971 def_bool y
972 prompt "s390 support for virtio devices"
973 select TTY
974 select VIRTUALIZATION
975 select VIRTIO
976 select VIRTIO_CONSOLE
977 help
978 Enabling this option adds support for virtio based paravirtual device
979 drivers on s390.
980
981 Select this option if you want to run the kernel as a guest under
982 the KVM hypervisor.
983
984endmenu