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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
1config MMU
2 def_bool y
3
4config ZONE_DMA
5 def_bool y
6
7config LOCKDEP_SUPPORT
8 def_bool y
9
10config STACKTRACE_SUPPORT
11 def_bool y
12
13config HAVE_LATENCYTOP_SUPPORT
14 def_bool y
15
16config RWSEM_GENERIC_SPINLOCK
17 bool
18
19config RWSEM_XCHGADD_ALGORITHM
20 def_bool y
21
22config ARCH_HAS_ILOG2_U32
23 def_bool n
24
25config ARCH_HAS_ILOG2_U64
26 def_bool n
27
28config GENERIC_HWEIGHT
29 def_bool y
30
31config GENERIC_BUG
32 def_bool y if BUG
33
34config GENERIC_BUG_RELATIVE_POINTERS
35 def_bool y
36
37config ARCH_DMA_ADDR_T_64BIT
38 def_bool 64BIT
39
40config GENERIC_LOCKBREAK
41 def_bool y if SMP && PREEMPT
42
43config PGSTE
44 def_bool y if KVM
45
46config ARCH_SUPPORTS_DEBUG_PAGEALLOC
47 def_bool y
48
49config KEXEC
50 def_bool y
51
52config AUDIT_ARCH
53 def_bool y
54
55config NO_IOPORT_MAP
56 def_bool y
57
58config PCI_QUIRKS
59 def_bool n
60
61config S390
62 def_bool y
63 select ARCH_DISCARD_MEMBLOCK
64 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
65 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
66 select ARCH_HAVE_NMI_SAFE_CMPXCHG
67 select ARCH_INLINE_READ_LOCK
68 select ARCH_INLINE_READ_LOCK_BH
69 select ARCH_INLINE_READ_LOCK_IRQ
70 select ARCH_INLINE_READ_LOCK_IRQSAVE
71 select ARCH_INLINE_READ_TRYLOCK
72 select ARCH_INLINE_READ_UNLOCK
73 select ARCH_INLINE_READ_UNLOCK_BH
74 select ARCH_INLINE_READ_UNLOCK_IRQ
75 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
76 select ARCH_INLINE_SPIN_LOCK
77 select ARCH_INLINE_SPIN_LOCK_BH
78 select ARCH_INLINE_SPIN_LOCK_IRQ
79 select ARCH_INLINE_SPIN_LOCK_IRQSAVE
80 select ARCH_INLINE_SPIN_TRYLOCK
81 select ARCH_INLINE_SPIN_TRYLOCK_BH
82 select ARCH_INLINE_SPIN_UNLOCK
83 select ARCH_INLINE_SPIN_UNLOCK_BH
84 select ARCH_INLINE_SPIN_UNLOCK_IRQ
85 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
86 select ARCH_INLINE_WRITE_LOCK
87 select ARCH_INLINE_WRITE_LOCK_BH
88 select ARCH_INLINE_WRITE_LOCK_IRQ
89 select ARCH_INLINE_WRITE_LOCK_IRQSAVE
90 select ARCH_INLINE_WRITE_TRYLOCK
91 select ARCH_INLINE_WRITE_UNLOCK
92 select ARCH_INLINE_WRITE_UNLOCK_BH
93 select ARCH_INLINE_WRITE_UNLOCK_IRQ
94 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
95 select ARCH_SAVE_PAGE_KEYS if HIBERNATION
96 select ARCH_USE_CMPXCHG_LOCKREF
97 select ARCH_WANT_IPC_PARSE_VERSION
98 select BUILDTIME_EXTABLE_SORT
99 select CLONE_BACKWARDS2
100 select GENERIC_CLOCKEVENTS
101 select GENERIC_CPU_DEVICES if !SMP
102 select GENERIC_FIND_FIRST_BIT
103 select GENERIC_SMP_IDLE_THREAD
104 select GENERIC_TIME_VSYSCALL
105 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
106 select HAVE_ARCH_AUDITSYSCALL
107 select HAVE_ARCH_JUMP_LABEL if !MARCH_G5
108 select HAVE_ARCH_SECCOMP_FILTER
109 select HAVE_ARCH_TRACEHOOK
110 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT
111 select HAVE_BPF_JIT if 64BIT && PACK_STACK
112 select HAVE_CMPXCHG_DOUBLE
113 select HAVE_CMPXCHG_LOCAL
114 select HAVE_C_RECORDMCOUNT
115 select HAVE_DEBUG_KMEMLEAK
116 select HAVE_DYNAMIC_FTRACE
117 select HAVE_FTRACE_MCOUNT_RECORD
118 select HAVE_FUNCTION_GRAPH_TRACER
119 select HAVE_FUNCTION_TRACER
120 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
121 select HAVE_FUTEX_CMPXCHG if FUTEX
122 select HAVE_KERNEL_BZIP2
123 select HAVE_KERNEL_GZIP
124 select HAVE_KERNEL_LZ4
125 select HAVE_KERNEL_LZMA
126 select HAVE_KERNEL_LZO
127 select HAVE_KERNEL_XZ
128 select HAVE_KPROBES
129 select HAVE_KRETPROBES
130 select HAVE_KVM if 64BIT
131 select HAVE_MEMBLOCK
132 select HAVE_MEMBLOCK_NODE_MAP
133 select HAVE_MOD_ARCH_SPECIFIC
134 select HAVE_OPROFILE
135 select HAVE_PERF_EVENTS
136 select HAVE_REGS_AND_STACK_ACCESS_API
137 select HAVE_SYSCALL_TRACEPOINTS
138 select HAVE_UID16 if 32BIT
139 select HAVE_VIRT_CPU_ACCOUNTING
140 select KTIME_SCALAR if 32BIT
141 select MODULES_USE_ELF_RELA
142 select OLD_SIGACTION
143 select OLD_SIGSUSPEND3
144 select SYSCTL_EXCEPTION_TRACE
145 select TTY
146 select VIRT_CPU_ACCOUNTING
147 select VIRT_TO_BUS
148
149config SCHED_OMIT_FRAME_POINTER
150 def_bool y
151
152source "init/Kconfig"
153
154source "kernel/Kconfig.freezer"
155
156menu "Processor type and features"
157
158config HAVE_MARCH_Z900_FEATURES
159 def_bool n
160
161config HAVE_MARCH_Z990_FEATURES
162 def_bool n
163 select HAVE_MARCH_Z900_FEATURES
164
165config HAVE_MARCH_Z9_109_FEATURES
166 def_bool n
167 select HAVE_MARCH_Z990_FEATURES
168
169config HAVE_MARCH_Z10_FEATURES
170 def_bool n
171 select HAVE_MARCH_Z9_109_FEATURES
172
173config HAVE_MARCH_Z196_FEATURES
174 def_bool n
175 select HAVE_MARCH_Z10_FEATURES
176
177config HAVE_MARCH_ZEC12_FEATURES
178 def_bool n
179 select HAVE_MARCH_Z196_FEATURES
180
181choice
182 prompt "Processor type"
183 default MARCH_G5
184
185config MARCH_G5
186 bool "System/390 model G5 and G6"
187 depends on !64BIT
188 help
189 Select this to build a 31 bit kernel that works
190 on all ESA/390 and z/Architecture machines.
191
192config MARCH_Z900
193 bool "IBM zSeries model z800 and z900"
194 select HAVE_MARCH_Z900_FEATURES if 64BIT
195 help
196 Select this to enable optimizations for model z800/z900 (2064 and
197 2066 series). This will enable some optimizations that are not
198 available on older ESA/390 (31 Bit) only CPUs.
199
200config MARCH_Z990
201 bool "IBM zSeries model z890 and z990"
202 select HAVE_MARCH_Z990_FEATURES if 64BIT
203 help
204 Select this to enable optimizations for model z890/z990 (2084 and
205 2086 series). The kernel will be slightly faster but will not work
206 on older machines.
207
208config MARCH_Z9_109
209 bool "IBM System z9"
210 select HAVE_MARCH_Z9_109_FEATURES if 64BIT
211 help
212 Select this to enable optimizations for IBM System z9 (2094 and
213 2096 series). The kernel will be slightly faster but will not work
214 on older machines.
215
216config MARCH_Z10
217 bool "IBM System z10"
218 select HAVE_MARCH_Z10_FEATURES if 64BIT
219 help
220 Select this to enable optimizations for IBM System z10 (2097 and
221 2098 series). The kernel will be slightly faster but will not work
222 on older machines.
223
224config MARCH_Z196
225 bool "IBM zEnterprise 114 and 196"
226 select HAVE_MARCH_Z196_FEATURES if 64BIT
227 help
228 Select this to enable optimizations for IBM zEnterprise 114 and 196
229 (2818 and 2817 series). The kernel will be slightly faster but will
230 not work on older machines.
231
232config MARCH_ZEC12
233 bool "IBM zBC12 and zEC12"
234 select HAVE_MARCH_ZEC12_FEATURES if 64BIT
235 help
236 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
237 2827 series). The kernel will be slightly faster but will not work on
238 older machines.
239
240endchoice
241
242config MARCH_G5_TUNE
243 def_bool TUNE_G5 || MARCH_G5 && TUNE_DEFAULT
244
245config MARCH_Z900_TUNE
246 def_bool TUNE_Z900 || MARCH_Z900 && TUNE_DEFAULT
247
248config MARCH_Z990_TUNE
249 def_bool TUNE_Z990 || MARCH_Z990 && TUNE_DEFAULT
250
251config MARCH_Z9_109_TUNE
252 def_bool TUNE_Z9_109 || MARCH_Z9_109 && TUNE_DEFAULT
253
254config MARCH_Z10_TUNE
255 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
256
257config MARCH_Z196_TUNE
258 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
259
260config MARCH_ZEC12_TUNE
261 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
262
263choice
264 prompt "Tune code generation"
265 default TUNE_DEFAULT
266 help
267 Cause the compiler to tune (-mtune) the generated code for a machine.
268 This will make the code run faster on the selected machine but
269 somewhat slower on other machines.
270 This option only changes how the compiler emits instructions, not the
271 selection of instructions itself, so the resulting kernel will run on
272 all other machines.
273
274config TUNE_DEFAULT
275 bool "Default"
276 help
277 Tune the generated code for the target processor for which the kernel
278 will be compiled.
279
280config TUNE_G5
281 bool "System/390 model G5 and G6"
282
283config TUNE_Z900
284 bool "IBM zSeries model z800 and z900"
285
286config TUNE_Z990
287 bool "IBM zSeries model z890 and z990"
288
289config TUNE_Z9_109
290 bool "IBM System z9"
291
292config TUNE_Z10
293 bool "IBM System z10"
294
295config TUNE_Z196
296 bool "IBM zEnterprise 114 and 196"
297
298config TUNE_ZEC12
299 bool "IBM zBC12 and zEC12"
300
301endchoice
302
303config 64BIT
304 def_bool y
305 prompt "64 bit kernel"
306 help
307 Select this option if you have an IBM z/Architecture machine
308 and want to use the 64 bit addressing mode.
309
310config 32BIT
311 def_bool y if !64BIT
312
313config COMPAT
314 def_bool y
315 prompt "Kernel support for 31 bit emulation"
316 depends on 64BIT
317 select COMPAT_BINFMT_ELF if BINFMT_ELF
318 select ARCH_WANT_OLD_COMPAT_IPC
319 select COMPAT_OLD_SIGACTION
320 help
321 Select this option if you want to enable your system kernel to
322 handle system-calls from ELF binaries for 31 bit ESA. This option
323 (and some other stuff like libraries and such) is needed for
324 executing 31 bit applications. It is safe to say "Y".
325
326config SYSVIPC_COMPAT
327 def_bool y if COMPAT && SYSVIPC
328
329config KEYS_COMPAT
330 def_bool y if COMPAT && KEYS
331
332config SMP
333 def_bool y
334 prompt "Symmetric multi-processing support"
335 ---help---
336 This enables support for systems with more than one CPU. If you have
337 a system with only one CPU, like most personal computers, say N. If
338 you have a system with more than one CPU, say Y.
339
340 If you say N here, the kernel will run on uni- and multiprocessor
341 machines, but will use only one CPU of a multiprocessor machine. If
342 you say Y here, the kernel will run on many, but not all,
343 uniprocessor machines. On a uniprocessor machine, the kernel
344 will run faster if you say N here.
345
346 See also the SMP-HOWTO available at
347 <http://www.tldp.org/docs.html#howto>.
348
349 Even if you don't know what to do here, say Y.
350
351config NR_CPUS
352 int "Maximum number of CPUs (2-256)"
353 range 2 256
354 depends on SMP
355 default "32" if !64BIT
356 default "64" if 64BIT
357 help
358 This allows you to specify the maximum number of CPUs which this
359 kernel will support. The maximum supported value is 256 and the
360 minimum value which makes sense is 2.
361
362 This is purely to save memory - each supported CPU adds
363 approximately sixteen kilobytes to the kernel image.
364
365config HOTPLUG_CPU
366 def_bool y
367 prompt "Support for hot-pluggable CPUs"
368 depends on SMP
369 help
370 Say Y here to be able to turn CPUs off and on. CPUs
371 can be controlled through /sys/devices/system/cpu/cpu#.
372 Say N if you want to disable CPU hotplug.
373
374config SCHED_MC
375 def_bool n
376
377config SCHED_BOOK
378 def_bool y
379 prompt "Book scheduler support"
380 depends on SMP
381 select SCHED_MC
382 help
383 Book scheduler support improves the CPU scheduler's decision making
384 when dealing with machines that have several books.
385
386source kernel/Kconfig.preempt
387
388config MATHEMU
389 def_bool y
390 prompt "IEEE FPU emulation"
391 depends on MARCH_G5
392 help
393 This option is required for IEEE compliant floating point arithmetic
394 on older ESA/390 machines. Say Y unless you know your machine doesn't
395 need this.
396
397source kernel/Kconfig.hz
398
399endmenu
400
401menu "Memory setup"
402
403config ARCH_SPARSEMEM_ENABLE
404 def_bool y
405 select SPARSEMEM_VMEMMAP_ENABLE
406 select SPARSEMEM_VMEMMAP
407 select SPARSEMEM_STATIC if !64BIT
408
409config ARCH_SPARSEMEM_DEFAULT
410 def_bool y
411
412config ARCH_SELECT_MEMORY_MODEL
413 def_bool y
414
415config ARCH_ENABLE_MEMORY_HOTPLUG
416 def_bool y if SPARSEMEM
417
418config ARCH_ENABLE_MEMORY_HOTREMOVE
419 def_bool y
420
421config ARCH_ENABLE_SPLIT_PMD_PTLOCK
422 def_bool y
423 depends on 64BIT
424
425config FORCE_MAX_ZONEORDER
426 int
427 default "9"
428
429source "mm/Kconfig"
430
431config PACK_STACK
432 def_bool y
433 prompt "Pack kernel stack"
434 help
435 This option enables the compiler option -mkernel-backchain if it
436 is available. If the option is available the compiler supports
437 the new stack layout which dramatically reduces the minimum stack
438 frame size. With an old compiler a non-leaf function needs a
439 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
440 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
441 and 24 byte on 64 bit.
442
443 Say Y if you are unsure.
444
445config CHECK_STACK
446 def_bool y
447 prompt "Detect kernel stack overflow"
448 help
449 This option enables the compiler option -mstack-guard and
450 -mstack-size if they are available. If the compiler supports them
451 it will emit additional code to each function prolog to trigger
452 an illegal operation if the kernel stack is about to overflow.
453
454 Say N if you are unsure.
455
456config STACK_GUARD
457 int "Size of the guard area (128-1024)"
458 range 128 1024
459 depends on CHECK_STACK
460 default "256"
461 help
462 This allows you to specify the size of the guard area at the lower
463 end of the kernel stack. If the kernel stack points into the guard
464 area on function entry an illegal operation is triggered. The size
465 needs to be a power of 2. Please keep in mind that the size of an
466 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
467 The minimum size for the stack guard should be 256 for 31 bit and
468 512 for 64 bit.
469
470config WARN_DYNAMIC_STACK
471 def_bool n
472 prompt "Emit compiler warnings for function with dynamic stack usage"
473 help
474 This option enables the compiler option -mwarn-dynamicstack. If the
475 compiler supports this options generates warnings for functions
476 that dynamically allocate stack space using alloca.
477
478 Say N if you are unsure.
479
480endmenu
481
482menu "I/O subsystem"
483
484config QDIO
485 def_tristate y
486 prompt "QDIO support"
487 ---help---
488 This driver provides the Queued Direct I/O base support for
489 IBM System z.
490
491 To compile this driver as a module, choose M here: the
492 module will be called qdio.
493
494 If unsure, say Y.
495
496menuconfig PCI
497 bool "PCI support"
498 default n
499 depends on 64BIT
500 select PCI_MSI
501 help
502 Enable PCI support.
503
504if PCI
505
506config PCI_NR_FUNCTIONS
507 int "Maximum number of PCI functions (1-4096)"
508 range 1 4096
509 default "64"
510 help
511 This allows you to specify the maximum number of PCI functions which
512 this kernel will support.
513
514config PCI_NR_MSI
515 int "Maximum number of MSI interrupts (64-32768)"
516 range 64 32768
517 default "256"
518 help
519 This defines the number of virtual interrupts the kernel will
520 provide for MSI interrupts. If you configure your system to have
521 too few drivers will fail to allocate MSI interrupts for all
522 PCI devices.
523
524source "drivers/pci/Kconfig"
525source "drivers/pci/pcie/Kconfig"
526source "drivers/pci/hotplug/Kconfig"
527
528endif # PCI
529
530config PCI_DOMAINS
531 def_bool PCI
532
533config HAS_IOMEM
534 def_bool PCI
535
536config IOMMU_HELPER
537 def_bool PCI
538
539config HAS_DMA
540 def_bool PCI
541 select HAVE_DMA_API_DEBUG
542
543config NEED_SG_DMA_LENGTH
544 def_bool PCI
545
546config HAVE_DMA_ATTRS
547 def_bool PCI
548
549config NEED_DMA_MAP_STATE
550 def_bool PCI
551
552config CHSC_SCH
553 def_tristate m
554 prompt "Support for CHSC subchannels"
555 help
556 This driver allows usage of CHSC subchannels. A CHSC subchannel
557 is usually present on LPAR only.
558 The driver creates a device /dev/chsc, which may be used to
559 obtain I/O configuration information about the machine and
560 to issue asynchronous chsc commands (DANGEROUS).
561 You will usually only want to use this interface on a special
562 LPAR designated for system management.
563
564 To compile this driver as a module, choose M here: the
565 module will be called chsc_sch.
566
567 If unsure, say N.
568
569config SCM_BUS
570 def_bool y
571 depends on 64BIT
572 prompt "SCM bus driver"
573 help
574 Bus driver for Storage Class Memory.
575
576config EADM_SCH
577 def_tristate m
578 prompt "Support for EADM subchannels"
579 depends on SCM_BUS
580 help
581 This driver allows usage of EADM subchannels. EADM subchannels act
582 as a communication vehicle for SCM increments.
583
584 To compile this driver as a module, choose M here: the
585 module will be called eadm_sch.
586
587endmenu
588
589menu "Dump support"
590
591config CRASH_DUMP
592 bool "kernel crash dumps"
593 depends on 64BIT && SMP
594 select KEXEC
595 select ZFCPDUMP
596 help
597 Generate crash dump after being started by kexec.
598 Crash dump kernels are loaded in the main kernel with kexec-tools
599 into a specially reserved region and then later executed after
600 a crash by kdump/kexec.
601 For more details see Documentation/kdump/kdump.txt
602
603config ZFCPDUMP
604 def_bool n
605 prompt "zfcpdump support"
606 depends on 64BIT && SMP
607 help
608 Select this option if you want to build an zfcpdump enabled kernel.
609 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
610
611endmenu
612
613menu "Executable file formats / Emulations"
614
615source "fs/Kconfig.binfmt"
616
617config SECCOMP
618 def_bool y
619 prompt "Enable seccomp to safely compute untrusted bytecode"
620 depends on PROC_FS
621 help
622 This kernel feature is useful for number crunching applications
623 that may need to compute untrusted bytecode during their
624 execution. By using pipes or other transports made available to
625 the process as file descriptors supporting the read/write
626 syscalls, it's possible to isolate those applications in
627 their own address space using seccomp. Once seccomp is
628 enabled via /proc/<pid>/seccomp, it cannot be disabled
629 and the task is only allowed to execute a few safe syscalls
630 defined by each seccomp mode.
631
632 If unsure, say Y.
633
634endmenu
635
636menu "Power Management"
637
638config ARCH_HIBERNATION_POSSIBLE
639 def_bool y if 64BIT
640
641source "kernel/power/Kconfig"
642
643endmenu
644
645source "net/Kconfig"
646
647config PCMCIA
648 def_bool n
649
650config CCW
651 def_bool y
652
653source "drivers/Kconfig"
654
655source "fs/Kconfig"
656
657source "arch/s390/Kconfig.debug"
658
659source "security/Kconfig"
660
661source "crypto/Kconfig"
662
663source "lib/Kconfig"
664
665menu "Virtualization"
666
667config PFAULT
668 def_bool y
669 prompt "Pseudo page fault support"
670 help
671 Select this option, if you want to use PFAULT pseudo page fault
672 handling under VM. If running native or in LPAR, this option
673 has no effect. If your VM does not support PFAULT, PAGEEX
674 pseudo page fault handling will be used.
675 Note that VM 4.2 supports PFAULT but has a bug in its
676 implementation that causes some problems.
677 Everybody who wants to run Linux under VM != VM4.2 should select
678 this option.
679
680config SHARED_KERNEL
681 bool "VM shared kernel support"
682 depends on !JUMP_LABEL
683 help
684 Select this option, if you want to share the text segment of the
685 Linux kernel between different VM guests. This reduces memory
686 usage with lots of guests but greatly increases kernel size.
687 Also if a kernel was IPL'ed from a shared segment the kexec system
688 call will not work.
689 You should only select this option if you know what you are
690 doing and want to exploit this feature.
691
692config CMM
693 def_tristate n
694 prompt "Cooperative memory management"
695 help
696 Select this option, if you want to enable the kernel interface
697 to reduce the memory size of the system. This is accomplished
698 by allocating pages of memory and put them "on hold". This only
699 makes sense for a system running under VM where the unused pages
700 will be reused by VM for other guest systems. The interface
701 allows an external monitor to balance memory of many systems.
702 Everybody who wants to run Linux under VM should select this
703 option.
704
705config CMM_IUCV
706 def_bool y
707 prompt "IUCV special message interface to cooperative memory management"
708 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
709 help
710 Select this option to enable the special message interface to
711 the cooperative memory management.
712
713config APPLDATA_BASE
714 def_bool n
715 prompt "Linux - VM Monitor Stream, base infrastructure"
716 depends on PROC_FS
717 help
718 This provides a kernel interface for creating and updating z/VM APPLDATA
719 monitor records. The monitor records are updated at certain time
720 intervals, once the timer is started.
721 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
722 i.e. enables or disables monitoring on the Linux side.
723 A custom interval value (in seconds) can be written to
724 /proc/appldata/interval.
725
726 Defaults are 60 seconds interval and timer off.
727 The /proc entries can also be read from, showing the current settings.
728
729config APPLDATA_MEM
730 def_tristate m
731 prompt "Monitor memory management statistics"
732 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
733 help
734 This provides memory management related data to the Linux - VM Monitor
735 Stream, like paging/swapping rate, memory utilisation, etc.
736 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
737 APPLDATA monitor record, i.e. enables or disables monitoring this record
738 on the z/VM side.
739
740 Default is disabled.
741 The /proc entry can also be read from, showing the current settings.
742
743 This can also be compiled as a module, which will be called
744 appldata_mem.o.
745
746config APPLDATA_OS
747 def_tristate m
748 prompt "Monitor OS statistics"
749 depends on APPLDATA_BASE
750 help
751 This provides OS related data to the Linux - VM Monitor Stream, like
752 CPU utilisation, etc.
753 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
754 APPLDATA monitor record, i.e. enables or disables monitoring this record
755 on the z/VM side.
756
757 Default is disabled.
758 This can also be compiled as a module, which will be called
759 appldata_os.o.
760
761config APPLDATA_NET_SUM
762 def_tristate m
763 prompt "Monitor overall network statistics"
764 depends on APPLDATA_BASE && NET
765 help
766 This provides network related data to the Linux - VM Monitor Stream,
767 currently there is only a total sum of network I/O statistics, no
768 per-interface data.
769 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
770 APPLDATA monitor record, i.e. enables or disables monitoring this record
771 on the z/VM side.
772
773 Default is disabled.
774 This can also be compiled as a module, which will be called
775 appldata_net_sum.o.
776
777config S390_HYPFS_FS
778 def_bool y
779 prompt "s390 hypervisor file system support"
780 select SYS_HYPERVISOR
781 help
782 This is a virtual file system intended to provide accounting
783 information in an s390 hypervisor environment.
784
785source "arch/s390/kvm/Kconfig"
786
787config S390_GUEST
788 def_bool y
789 prompt "s390 support for virtio devices"
790 depends on 64BIT
791 select TTY
792 select VIRTUALIZATION
793 select VIRTIO
794 select VIRTIO_CONSOLE
795 help
796 Enabling this option adds support for virtio based paravirtual device
797 drivers on s390.
798
799 Select this option if you want to run the kernel as a guest under
800 the KVM hypervisor.
801
802endmenu