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b2441318 1# SPDX-License-Identifier: GPL-2.0
1da177e4 2config MMU
61d48c2c 3 def_bool y
1da177e4 4
66701b14 5config ZONE_DMA
69dbb2f7 6 def_bool y
66701b14 7
2fd92273
HC
8config CPU_BIG_ENDIAN
9 def_bool y
10
2b105ff9 11config LOCKDEP_SUPPORT
61d48c2c 12 def_bool y
2b105ff9 13
5bdc9b44 14config STACKTRACE_SUPPORT
61d48c2c 15 def_bool y
5bdc9b44 16
1da177e4
LT
17config RWSEM_GENERIC_SPINLOCK
18 bool
19
20config RWSEM_XCHGADD_ALGORITHM
61d48c2c 21 def_bool y
1da177e4 22
f0d1b0b3 23config ARCH_HAS_ILOG2_U32
6f9a3c33 24 def_bool n
f0d1b0b3
DH
25
26config ARCH_HAS_ILOG2_U64
6f9a3c33 27 def_bool n
f0d1b0b3 28
7e33db4e 29config GENERIC_HWEIGHT
61d48c2c 30 def_bool y
7e33db4e 31
c0007f1a 32config GENERIC_BUG
6f9a3c33 33 def_bool y if BUG
c0007f1a 34
52499f40
HC
35config GENERIC_BUG_RELATIVE_POINTERS
36 def_bool y
37
b6b40c53 38config GENERIC_LOCKBREAK
6f9a3c33 39 def_bool y if SMP && PREEMPT
b6b40c53 40
402b0862 41config PGSTE
6f9a3c33 42 def_bool y if KVM
402b0862 43
6a11f75b
AM
44config ARCH_SUPPORTS_DEBUG_PAGEALLOC
45 def_bool y
46
843c48fd
JG
47config AUDIT_ARCH
48 def_bool y
49
ce816fa8 50config NO_IOPORT_MAP
c8717a3d
JG
51 def_bool y
52
53config PCI_QUIRKS
54 def_bool n
55
2a0a5b22 56config ARCH_SUPPORTS_UPROBES
5a79859a 57 def_bool y
2a0a5b22 58
347a8dc3 59config S390
61d48c2c 60 def_bool y
23fefe11 61 select ARCH_BINFMT_ELF_STATE
21266be9 62 select ARCH_HAS_DEVMEM_IS_ALLOWED
2b68f6ca 63 select ARCH_HAS_ELF_RANDOMIZE
79962038 64 select ARCH_HAS_FORTIFY_SOURCE
957e3fac 65 select ARCH_HAS_GCOV_PROFILE_ALL
e1073d1e 66 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
907fa061 67 select ARCH_HAS_KCOV
3010a5ea 68 select ARCH_HAS_PTE_SPECIAL
d2852a22 69 select ARCH_HAS_SET_MEMORY
47523c98 70 select ARCH_HAS_SG_CHAIN
ad21fc4f
LA
71 select ARCH_HAS_STRICT_KERNEL_RWX
72 select ARCH_HAS_STRICT_MODULE_RWX
c42d8c7d 73 select ARCH_HAS_UBSAN_SANITIZE_ALL
0e0d04a8 74 select ARCH_HAVE_NMI_SAFE_CMPXCHG
6beb0009
TG
75 select ARCH_INLINE_READ_LOCK
76 select ARCH_INLINE_READ_LOCK_BH
77 select ARCH_INLINE_READ_LOCK_IRQ
78 select ARCH_INLINE_READ_LOCK_IRQSAVE
0e0d04a8 79 select ARCH_INLINE_READ_TRYLOCK
6beb0009
TG
80 select ARCH_INLINE_READ_UNLOCK
81 select ARCH_INLINE_READ_UNLOCK_BH
82 select ARCH_INLINE_READ_UNLOCK_IRQ
83 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
0e0d04a8
HC
84 select ARCH_INLINE_SPIN_LOCK
85 select ARCH_INLINE_SPIN_LOCK_BH
86 select ARCH_INLINE_SPIN_LOCK_IRQ
87 select ARCH_INLINE_SPIN_LOCK_IRQSAVE
88 select ARCH_INLINE_SPIN_TRYLOCK
89 select ARCH_INLINE_SPIN_TRYLOCK_BH
90 select ARCH_INLINE_SPIN_UNLOCK
91 select ARCH_INLINE_SPIN_UNLOCK_BH
92 select ARCH_INLINE_SPIN_UNLOCK_IRQ
93 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
6beb0009
TG
94 select ARCH_INLINE_WRITE_LOCK
95 select ARCH_INLINE_WRITE_LOCK_BH
96 select ARCH_INLINE_WRITE_LOCK_IRQ
97 select ARCH_INLINE_WRITE_LOCK_IRQSAVE
0e0d04a8 98 select ARCH_INLINE_WRITE_TRYLOCK
6beb0009
TG
99 select ARCH_INLINE_WRITE_UNLOCK
100 select ARCH_INLINE_WRITE_UNLOCK_BH
101 select ARCH_INLINE_WRITE_UNLOCK_IRQ
102 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
0e0d04a8 103 select ARCH_SAVE_PAGE_KEYS if HIBERNATION
36e7fdaa 104 select ARCH_SUPPORTS_ATOMIC_RMW
a763bc8b 105 select ARCH_SUPPORTS_NUMA_BALANCING
295d8fa9 106 select ARCH_USE_BUILTIN_BSWAP
efc1d23b 107 select ARCH_USE_CMPXCHG_LOCKREF
3f6813b9 108 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
c1d7e01d 109 select ARCH_WANT_IPC_PARSE_VERSION
0e0d04a8
HC
110 select BUILDTIME_EXTABLE_SORT
111 select CLONE_BACKWARDS2
5d6a0163 112 select DYNAMIC_FTRACE if FUNCTION_TRACER
0e0d04a8 113 select GENERIC_CLOCKEVENTS
8f00b3e2 114 select GENERIC_CPU_AUTOPROBE
0e0d04a8 115 select GENERIC_CPU_DEVICES if !SMP
d424986f 116 select GENERIC_CPU_VULNERABILITIES
746479cd 117 select GENERIC_FIND_FIRST_BIT
e80e7813 118 select GENERIC_SMP_IDLE_THREAD
79c74ecb 119 select GENERIC_TIME_VSYSCALL
0e0d04a8 120 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
7a017721 121 select HAVE_ARCH_AUDITSYSCALL
5a79859a 122 select HAVE_ARCH_JUMP_LABEL
fff7fb0b 123 select CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES
c63cb468 124 select HAVE_ARCH_SECCOMP_FILTER
5614dd92 125 select HAVE_ARCH_SOFT_DIRTY
0e0d04a8 126 select HAVE_ARCH_TRACEHOOK
5a79859a 127 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
ce3dc447 128 select HAVE_ARCH_VMAP_STACK
6077776b 129 select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
0e0d04a8
HC
130 select HAVE_CMPXCHG_DOUBLE
131 select HAVE_CMPXCHG_LOCAL
f50c0e63 132 select HAVE_COPY_THREAD_TLS
0e0d04a8 133 select HAVE_DEBUG_KMEMLEAK
e1231b0e 134 select HAVE_DMA_CONTIGUOUS
002e6745 135 select DMA_DIRECT_OPS
5a79859a
HC
136 select HAVE_DYNAMIC_FTRACE
137 select HAVE_DYNAMIC_FTRACE_WITH_REGS
9078a549 138 select HAVE_EFFICIENT_UNALIGNED_ACCESS
d983c89c 139 select HAVE_FENTRY
0e0d04a8 140 select HAVE_FTRACE_MCOUNT_RECORD
5a79859a
HC
141 select HAVE_FUNCTION_GRAPH_TRACER
142 select HAVE_FUNCTION_TRACER
03b8c7b6 143 select HAVE_FUTEX_CMPXCHG if FUTEX
bc00b3ec 144 select HAVE_GCC_PLUGINS
0e0d04a8
HC
145 select HAVE_KERNEL_BZIP2
146 select HAVE_KERNEL_GZIP
8e2872ce 147 select HAVE_KERNEL_LZ4
0e0d04a8
HC
148 select HAVE_KERNEL_LZMA
149 select HAVE_KERNEL_LZO
89b5202e 150 select HAVE_KERNEL_UNCOMPRESSED
0e0d04a8
HC
151 select HAVE_KERNEL_XZ
152 select HAVE_KPROBES
153 select HAVE_KRETPROBES
5a79859a 154 select HAVE_KVM
21042d43 155 select HAVE_LIVEPATCH
c33eff60
HC
156 select HAVE_PERF_REGS
157 select HAVE_PERF_USER_STACK_DUMP
0e0d04a8
HC
158 select HAVE_MEMBLOCK
159 select HAVE_MEMBLOCK_NODE_MAP
50be6345 160 select HAVE_MEMBLOCK_PHYS_MAP
786d35d4 161 select HAVE_MOD_ARCH_SPECIFIC
d983c89c 162 select HAVE_NOP_MCOUNT
0e0d04a8
HC
163 select HAVE_OPROFILE
164 select HAVE_PERF_EVENTS
165 select HAVE_REGS_AND_STACK_ACCESS_API
9d6d99e3 166 select HAVE_RSEQ
0e0d04a8 167 select HAVE_SYSCALL_TRACEPOINTS
0e0d04a8 168 select HAVE_VIRT_CPU_ACCOUNTING
786d35d4 169 select MODULES_USE_ELF_RELA
50be6345 170 select NO_BOOTMEM
7eddd99c 171 select OLD_SIGACTION
93bead43 172 select OLD_SIGSUSPEND3
bb98f396 173 select SPARSE_IRQ
0e0d04a8 174 select SYSCTL_EXCEPTION_TRACE
d5c352cd 175 select THREAD_INFO_IN_TASK
0563416b 176 select TTY
0e0d04a8 177 select VIRT_CPU_ACCOUNTING
40565b5a 178 select ARCH_HAS_SCALED_CPUTIME
93bead43 179 select VIRT_TO_BUS
42a0bb3f 180 select HAVE_NMI
3a368f74 181
1da177e4 182
fca3e357 183config SCHED_OMIT_FRAME_POINTER
6f9a3c33 184 def_bool y
fca3e357 185
c81956c9
KS
186config PGTABLE_LEVELS
187 int
1aea9b3f 188 default 5
c81956c9 189
21042d43
JS
190source "kernel/livepatch/Kconfig"
191
843c48fd
JG
192menu "Processor type and features"
193
194config HAVE_MARCH_Z900_FEATURES
195 def_bool n
196
197config HAVE_MARCH_Z990_FEATURES
198 def_bool n
199 select HAVE_MARCH_Z900_FEATURES
200
201config HAVE_MARCH_Z9_109_FEATURES
202 def_bool n
203 select HAVE_MARCH_Z990_FEATURES
204
205config HAVE_MARCH_Z10_FEATURES
206 def_bool n
207 select HAVE_MARCH_Z9_109_FEATURES
208
209config HAVE_MARCH_Z196_FEATURES
210 def_bool n
211 select HAVE_MARCH_Z10_FEATURES
212
991c1505
HC
213config HAVE_MARCH_ZEC12_FEATURES
214 def_bool n
215 select HAVE_MARCH_Z196_FEATURES
216
f8b2dcbd
MS
217config HAVE_MARCH_Z13_FEATURES
218 def_bool n
219 select HAVE_MARCH_ZEC12_FEATURES
220
6997c323
MS
221config HAVE_MARCH_Z14_FEATURES
222 def_bool n
223 select HAVE_MARCH_Z13_FEATURES
224
843c48fd
JG
225choice
226 prompt "Processor type"
7072276e 227 default MARCH_Z196
1da177e4 228
843c48fd
JG
229config MARCH_Z900
230 bool "IBM zSeries model z800 and z900"
5a79859a 231 select HAVE_MARCH_Z900_FEATURES
843c48fd
JG
232 help
233 Select this to enable optimizations for model z800/z900 (2064 and
234 2066 series). This will enable some optimizations that are not
235 available on older ESA/390 (31 Bit) only CPUs.
236
237config MARCH_Z990
238 bool "IBM zSeries model z890 and z990"
5a79859a 239 select HAVE_MARCH_Z990_FEATURES
843c48fd
JG
240 help
241 Select this to enable optimizations for model z890/z990 (2084 and
242 2086 series). The kernel will be slightly faster but will not work
243 on older machines.
244
245config MARCH_Z9_109
246 bool "IBM System z9"
5a79859a 247 select HAVE_MARCH_Z9_109_FEATURES
843c48fd
JG
248 help
249 Select this to enable optimizations for IBM System z9 (2094 and
250 2096 series). The kernel will be slightly faster but will not work
251 on older machines.
252
253config MARCH_Z10
254 bool "IBM System z10"
5a79859a 255 select HAVE_MARCH_Z10_FEATURES
843c48fd
JG
256 help
257 Select this to enable optimizations for IBM System z10 (2097 and
258 2098 series). The kernel will be slightly faster but will not work
259 on older machines.
260
261config MARCH_Z196
262 bool "IBM zEnterprise 114 and 196"
5a79859a 263 select HAVE_MARCH_Z196_FEATURES
843c48fd
JG
264 help
265 Select this to enable optimizations for IBM zEnterprise 114 and 196
266 (2818 and 2817 series). The kernel will be slightly faster but will
267 not work on older machines.
1da177e4 268
991c1505 269config MARCH_ZEC12
59471227 270 bool "IBM zBC12 and zEC12"
5a79859a 271 select HAVE_MARCH_ZEC12_FEATURES
991c1505 272 help
59471227
HC
273 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
274 2827 series). The kernel will be slightly faster but will not work on
275 older machines.
991c1505 276
f8b2dcbd 277config MARCH_Z13
bb3aa614 278 bool "IBM z13s and z13"
5a79859a 279 select HAVE_MARCH_Z13_FEATURES
f8b2dcbd 280 help
bb3aa614
HC
281 Select this to enable optimizations for IBM z13s and z13 (2965 and
282 2964 series). The kernel will be slightly faster but will not work on
283 older machines.
f8b2dcbd 284
6997c323 285config MARCH_Z14
451239eb 286 bool "IBM z14 ZR1 and z14"
6997c323
MS
287 select HAVE_MARCH_Z14_FEATURES
288 help
451239eb
HC
289 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
290 and 3906 series). The kernel will be slightly faster but will not
291 work on older machines.
6997c323 292
843c48fd 293endchoice
1da177e4 294
1db9e051
HC
295config MARCH_Z900_TUNE
296 def_bool TUNE_Z900 || MARCH_Z900 && TUNE_DEFAULT
297
298config MARCH_Z990_TUNE
299 def_bool TUNE_Z990 || MARCH_Z990 && TUNE_DEFAULT
300
301config MARCH_Z9_109_TUNE
302 def_bool TUNE_Z9_109 || MARCH_Z9_109 && TUNE_DEFAULT
303
304config MARCH_Z10_TUNE
305 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
306
307config MARCH_Z196_TUNE
308 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
309
310config MARCH_ZEC12_TUNE
311 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
312
f8b2dcbd
MS
313config MARCH_Z13_TUNE
314 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
315
6997c323
MS
316config MARCH_Z14_TUNE
317 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
318
1db9e051
HC
319choice
320 prompt "Tune code generation"
321 default TUNE_DEFAULT
322 help
323 Cause the compiler to tune (-mtune) the generated code for a machine.
324 This will make the code run faster on the selected machine but
325 somewhat slower on other machines.
326 This option only changes how the compiler emits instructions, not the
327 selection of instructions itself, so the resulting kernel will run on
328 all other machines.
329
330config TUNE_DEFAULT
331 bool "Default"
332 help
333 Tune the generated code for the target processor for which the kernel
334 will be compiled.
335
1db9e051
HC
336config TUNE_Z900
337 bool "IBM zSeries model z800 and z900"
338
339config TUNE_Z990
340 bool "IBM zSeries model z890 and z990"
341
342config TUNE_Z9_109
343 bool "IBM System z9"
344
345config TUNE_Z10
346 bool "IBM System z10"
347
348config TUNE_Z196
349 bool "IBM zEnterprise 114 and 196"
350
351config TUNE_ZEC12
352 bool "IBM zBC12 and zEC12"
353
f8b2dcbd
MS
354config TUNE_Z13
355 bool "IBM z13"
356
6997c323
MS
357config TUNE_Z14
358 bool "IBM z14"
359
1db9e051
HC
360endchoice
361
347a8dc3 362config 64BIT
6f9a3c33 363 def_bool y
d9f7a745 364
843c48fd
JG
365config COMPAT
366 def_bool y
367 prompt "Kernel support for 31 bit emulation"
843c48fd
JG
368 select COMPAT_BINFMT_ELF if BINFMT_ELF
369 select ARCH_WANT_OLD_COMPAT_IPC
7eddd99c 370 select COMPAT_OLD_SIGACTION
2813893f 371 depends on MULTIUSER
843c48fd
JG
372 help
373 Select this option if you want to enable your system kernel to
374 handle system-calls from ELF binaries for 31 bit ESA. This option
375 (and some other stuff like libraries and such) is needed for
376 executing 31 bit applications. It is safe to say "Y".
377
378config SYSVIPC_COMPAT
379 def_bool y if COMPAT && SYSVIPC
380
1da177e4 381config SMP
6f9a3c33
MS
382 def_bool y
383 prompt "Symmetric multi-processing support"
1da177e4
LT
384 ---help---
385 This enables support for systems with more than one CPU. If you have
386 a system with only one CPU, like most personal computers, say N. If
387 you have a system with more than one CPU, say Y.
388
4a474157 389 If you say N here, the kernel will run on uni- and multiprocessor
1da177e4
LT
390 machines, but will use only one CPU of a multiprocessor machine. If
391 you say Y here, the kernel will run on many, but not all,
4a474157 392 uniprocessor machines. On a uniprocessor machine, the kernel
1da177e4
LT
393 will run faster if you say N here.
394
03502faa
AB
395 See also the SMP-HOWTO available at
396 <http://www.tldp.org/docs.html#howto>.
1da177e4
LT
397
398 Even if you don't know what to do here, say Y.
399
400config NR_CPUS
5c75a0da
HC
401 int "Maximum number of CPUs (2-512)"
402 range 2 512
1da177e4 403 depends on SMP
5a79859a 404 default "64"
1da177e4
LT
405 help
406 This allows you to specify the maximum number of CPUs which this
5c75a0da 407 kernel will support. The maximum supported value is 512 and the
1da177e4
LT
408 minimum value which makes sense is 2.
409
410 This is purely to save memory - each supported CPU adds
411 approximately sixteen kilobytes to the kernel image.
412
413config HOTPLUG_CPU
6f9a3c33
MS
414 def_bool y
415 prompt "Support for hot-pluggable CPUs"
1da177e4 416 depends on SMP
1da177e4
LT
417 help
418 Say Y here to be able to turn CPUs off and on. CPUs
419 can be controlled through /sys/devices/system/cpu/cpu#.
420 Say N if you want to disable CPU hotplug.
421
3a368f74
PH
422# Some NUMA nodes have memory ranges that span
423# other nodes. Even though a pfn is valid and
424# between a node's start and end pfns, it may not
425# reside on that node. See memmap_init_zone()
426# for details. <- They meant memory holes!
427config NODES_SPAN_OTHER_NODES
428 def_bool NUMA
429
430config NUMA
431 bool "NUMA support"
c095a949 432 depends on SMP && SCHED_TOPOLOGY
3a368f74
PH
433 default n
434 help
435 Enable NUMA support
436
437 This option adds NUMA support to the kernel.
438
439 An operation mode can be selected by appending
440 numa=<method> to the kernel command line.
441
442 The default behaviour is identical to appending numa=plain to
443 the command line. This will create just one node with all
444 available memory and all CPUs in it.
445
446config NODES_SHIFT
447 int "Maximum NUMA nodes (as a power of 2)"
448 range 1 10
449 depends on NUMA
450 default "4"
451 help
452 Specify the maximum number of NUMA nodes available on the target
453 system. Increases memory reserved to accommodate various tables.
454
c29a7baf
MH
455menu "Select NUMA modes"
456 depends on NUMA
457
458config NUMA_EMU
459 bool "NUMA emulation"
460 default y
461 help
462 Numa emulation mode will split the available system memory into
463 equal chunks which then are distributed over the configured number
464 of nodes in a round-robin manner.
465
466 The number of fake nodes is limited by the number of available memory
467 chunks (i.e. memory size / fake size) and the number of supported
468 nodes in the kernel.
469
470 The CPUs are assigned to the nodes in a way that partially respects
471 the original machine topology (if supported by the machine).
472 Fair distribution of the CPUs is not guaranteed.
473
474config EMU_SIZE
475 hex "NUMA emulation memory chunk size"
476 default 0x10000000
477 range 0x400000 0x100000000
478 depends on NUMA_EMU
479 help
480 Select the default size by which the memory is chopped and then
481 assigned to emulated NUMA nodes.
482
483 This can be overridden by specifying
484
485 emu_size=<n>
486
487 on the kernel command line where also suffixes K, M, G, and T are
488 supported.
489
490endmenu
9236b4dd
HC
491
492config SCHED_SMT
493 def_bool n
c29a7baf 494
8d11e021 495config SCHED_MC
83a24e32 496 def_bool n
8d11e021 497
4cb14bc8 498config SCHED_BOOK
10ad34bc
MS
499 def_bool n
500
adac0f1e
HC
501config SCHED_DRAWER
502 def_bool n
503
10ad34bc 504config SCHED_TOPOLOGY
6f9a3c33 505 def_bool y
10ad34bc 506 prompt "Topology scheduler support"
83a24e32 507 depends on SMP
10ad34bc 508 select SCHED_SMT
83a24e32 509 select SCHED_MC
10ad34bc 510 select SCHED_BOOK
adac0f1e 511 select SCHED_DRAWER
4cb14bc8 512 help
10ad34bc
MS
513 Topology scheduler support improves the CPU scheduler's decision
514 making when dealing with machines that have multi-threading,
515 multiple cores or multiple books.
4cb14bc8 516
843c48fd 517source kernel/Kconfig.hz
1da177e4 518
bdea9f6f
PR
519config KEXEC
520 def_bool y
521 select KEXEC_CORE
522
523config KEXEC_FILE
524 bool "kexec file based system call"
525 select KEXEC_CORE
526 select BUILD_BIN2C
527 depends on CRYPTO
528 depends on CRYPTO_SHA256
529 depends on CRYPTO_SHA256_S390
530 help
531 Enable the kexec file based system call. In contrast to the normal
532 kexec system call this system call takes file descriptors for the
533 kernel and initramfs as arguments.
534
535config ARCH_HAS_KEXEC_PURGATORY
536 def_bool y
537 depends on KEXEC_FILE
538
4c637cd8
HF
539config ARCH_RANDOM
540 def_bool y
541 prompt "s390 architectural random number generation API"
542 help
543 Enable the s390 architectural random number generation API
544 to provide random data for all consumers within the Linux
545 kernel.
546
547 When enabled the arch_random_* functions declared in linux/random.h
548 are implemented. The implementation is based on the s390 CPACF
549 instruction subfunction TRNG which provides a real true random
550 number generator.
551
552 If unsure, say Y.
553
d768bd89
MS
554config KERNEL_NOBP
555 def_bool n
556 prompt "Enable modified branch prediction for the kernel by default"
557 help
558 If this option is selected the kernel will switch to a modified
559 branch prediction mode if the firmware interface is available.
560 The modified branch prediction mode improves the behaviour in
561 regard to speculative execution.
562
563 With the option enabled the kernel parameter "nobp=0" or "nospec"
564 can be used to run the kernel in the normal branch prediction mode.
565
566 With the option disabled the modified branch prediction mode is
567 enabled with the "nobp=1" kernel parameter.
568
569 If unsure, say N.
570
f19fbd5e
MS
571config EXPOLINE
572 def_bool n
573 prompt "Avoid speculative indirect branches in the kernel"
574 help
575 Compile the kernel with the expoline compiler options to guard
576 against kernel-to-user data leaks by avoiding speculative indirect
577 branches.
578 Requires a compiler with -mindirect-branch=thunk support for full
579 protection. The kernel may run slower.
580
581 If unsure, say N.
582
583choice
584 prompt "Expoline default"
585 depends on EXPOLINE
586 default EXPOLINE_FULL
587
588config EXPOLINE_OFF
589 bool "spectre_v2=off"
590
6e179d64 591config EXPOLINE_AUTO
f19fbd5e
MS
592 bool "spectre_v2=auto"
593
594config EXPOLINE_FULL
595 bool "spectre_v2=on"
596
597endchoice
598
843c48fd 599endmenu
1da177e4 600
843c48fd 601menu "Memory setup"
1d057720 602
843c48fd 603config ARCH_SPARSEMEM_ENABLE
6f9a3c33 604 def_bool y
843c48fd
JG
605 select SPARSEMEM_VMEMMAP_ENABLE
606 select SPARSEMEM_VMEMMAP
e65e1fc2 607
843c48fd
JG
608config ARCH_SPARSEMEM_DEFAULT
609 def_bool y
1da177e4 610
843c48fd
JG
611config ARCH_SELECT_MEMORY_MODEL
612 def_bool y
1da177e4 613
843c48fd
JG
614config ARCH_ENABLE_MEMORY_HOTPLUG
615 def_bool y if SPARSEMEM
0efa4703 616
843c48fd
JG
617config ARCH_ENABLE_MEMORY_HOTREMOVE
618 def_bool y
e37f50e1 619
ec66ad66
MS
620config ARCH_ENABLE_SPLIT_PMD_PTLOCK
621 def_bool y
ec66ad66 622
843c48fd
JG
623config FORCE_MAX_ZONEORDER
624 int
625 default "9"
f861e405 626
b8402b95
HC
627config MAX_PHYSMEM_BITS
628 int "Maximum size of supported physical memory in bits (42-53)"
629 range 42 53
630 default "46"
631 help
632 This option specifies the maximum supported size of physical memory
633 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
634 Increasing the number of bits also increases the kernel image size.
635 By default 46 bits (64TB) are supported.
636
1da177e4 637config PACK_STACK
6f9a3c33
MS
638 def_bool y
639 prompt "Pack kernel stack"
1da177e4
LT
640 help
641 This option enables the compiler option -mkernel-backchain if it
642 is available. If the option is available the compiler supports
643 the new stack layout which dramatically reduces the minimum stack
644 frame size. With an old compiler a non-leaf function needs a
645 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
646 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
647 and 24 byte on 64 bit.
648
649 Say Y if you are unsure.
650
1da177e4 651config CHECK_STACK
6f9a3c33 652 def_bool y
ce3dc447 653 depends on !VMAP_STACK
6f9a3c33 654 prompt "Detect kernel stack overflow"
1da177e4
LT
655 help
656 This option enables the compiler option -mstack-guard and
657 -mstack-size if they are available. If the compiler supports them
658 it will emit additional code to each function prolog to trigger
659 an illegal operation if the kernel stack is about to overflow.
660
661 Say N if you are unsure.
662
663config STACK_GUARD
664 int "Size of the guard area (128-1024)"
665 range 128 1024
666 depends on CHECK_STACK
667 default "256"
668 help
669 This allows you to specify the size of the guard area at the lower
670 end of the kernel stack. If the kernel stack points into the guard
671 area on function entry an illegal operation is triggered. The size
672 needs to be a power of 2. Please keep in mind that the size of an
673 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
674 The minimum size for the stack guard should be 256 for 31 bit and
675 512 for 64 bit.
676
2c190da4 677config WARN_DYNAMIC_STACK
6f9a3c33 678 def_bool n
2c190da4 679 prompt "Emit compiler warnings for function with dynamic stack usage"
1da177e4 680 help
2c190da4
JG
681 This option enables the compiler option -mwarn-dynamicstack. If the
682 compiler supports this options generates warnings for functions
683 that dynamically allocate stack space using alloca.
1da177e4
LT
684
685 Say N if you are unsure.
686
843c48fd 687endmenu
3f22ab27 688
843c48fd 689menu "I/O subsystem"
1da177e4 690
1da177e4 691config QDIO
6f9a3c33
MS
692 def_tristate y
693 prompt "QDIO support"
1da177e4 694 ---help---
8129ee16 695 This driver provides the Queued Direct I/O base support for
efca13bc 696 IBM System z.
1da177e4
LT
697
698 To compile this driver as a module, choose M here: the
699 module will be called qdio.
700
701 If unsure, say Y.
702
c8717a3d
JG
703menuconfig PCI
704 bool "PCI support"
c8717a3d 705 select PCI_MSI
a4ce5a48 706 select IOMMU_HELPER
8128f23c 707 select IOMMU_SUPPORT
f616ab59 708 select NEED_DMA_MAP_STATE
86596f0a 709 select NEED_SG_DMA_LENGTH
a4ce5a48 710
c8717a3d
JG
711 help
712 Enable PCI support.
713
714if PCI
715
716config PCI_NR_FUNCTIONS
717 int "Maximum number of PCI functions (1-4096)"
718 range 1 4096
b18601b0 719 default "128"
c8717a3d
JG
720 help
721 This allows you to specify the maximum number of PCI functions which
722 this kernel will support.
723
724source "drivers/pci/Kconfig"
c8717a3d
JG
725
726endif # PCI
727
728config PCI_DOMAINS
729 def_bool PCI
730
731config HAS_IOMEM
732 def_bool PCI
733
9d92a7e1 734config CHSC_SCH
d9c11b1e 735 def_tristate m
6f9a3c33 736 prompt "Support for CHSC subchannels"
9d92a7e1
CH
737 help
738 This driver allows usage of CHSC subchannels. A CHSC subchannel
739 is usually present on LPAR only.
740 The driver creates a device /dev/chsc, which may be used to
741 obtain I/O configuration information about the machine and
742 to issue asynchronous chsc commands (DANGEROUS).
743 You will usually only want to use this interface on a special
744 LPAR designated for system management.
745
746 To compile this driver as a module, choose M here: the
747 module will be called chsc_sch.
748
749 If unsure, say N.
750
1d1c8f78
SO
751config SCM_BUS
752 def_bool y
1d1c8f78
SO
753 prompt "SCM bus driver"
754 help
755 Bus driver for Storage Class Memory.
756
eadb86ab
SO
757config EADM_SCH
758 def_tristate m
759 prompt "Support for EADM subchannels"
760 depends on SCM_BUS
761 help
762 This driver allows usage of EADM subchannels. EADM subchannels act
763 as a communication vehicle for SCM increments.
764
765 To compile this driver as a module, choose M here: the
766 module will be called eadm_sch.
767
63f1934d
DJS
768config VFIO_CCW
769 def_tristate n
770 prompt "Support for VFIO-CCW subchannels"
84cd8fc4 771 depends on S390_CCW_IOMMU && VFIO_MDEV
63f1934d
DJS
772 help
773 This driver allows usage of I/O subchannels via VFIO-CCW.
774
775 To compile this driver as a module, choose M here: the
776 module will be called vfio_ccw.
777
843c48fd
JG
778endmenu
779
780menu "Dump support"
781
782config CRASH_DUMP
783 bool "kernel crash dumps"
5a79859a 784 depends on SMP
843c48fd
JG
785 select KEXEC
786 help
787 Generate crash dump after being started by kexec.
788 Crash dump kernels are loaded in the main kernel with kexec-tools
789 into a specially reserved region and then later executed after
790 a crash by kdump/kexec.
843c48fd 791 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
bf28a597
MH
792 This option also enables s390 zfcpdump.
793 See also <file:Documentation/s390/zfcpdump.txt>
843c48fd
JG
794
795endmenu
796
843c48fd
JG
797config SECCOMP
798 def_bool y
799 prompt "Enable seccomp to safely compute untrusted bytecode"
800 depends on PROC_FS
801 help
802 This kernel feature is useful for number crunching applications
803 that may need to compute untrusted bytecode during their
804 execution. By using pipes or other transports made available to
805 the process as file descriptors supporting the read/write
806 syscalls, it's possible to isolate those applications in
807 their own address space using seccomp. Once seccomp is
808 enabled via /proc/<pid>/seccomp, it cannot be disabled
809 and the task is only allowed to execute a few safe syscalls
810 defined by each seccomp mode.
811
812 If unsure, say Y.
813
843c48fd
JG
814menu "Power Management"
815
816config ARCH_HIBERNATION_POSSIBLE
5a79859a 817 def_bool y
843c48fd
JG
818
819source "kernel/power/Kconfig"
820
821endmenu
822
843c48fd
JG
823config PCMCIA
824 def_bool n
825
826config CCW
827 def_bool y
828
b6ef86e9
UB
829config HAVE_PNETID
830 tristate
831 default (SMC || CCWGROUP)
832
843c48fd 833menu "Virtualization"
684de39b 834
1da177e4 835config PFAULT
6f9a3c33
MS
836 def_bool y
837 prompt "Pseudo page fault support"
1da177e4
LT
838 help
839 Select this option, if you want to use PFAULT pseudo page fault
840 handling under VM. If running native or in LPAR, this option
841 has no effect. If your VM does not support PFAULT, PAGEEX
842 pseudo page fault handling will be used.
843 Note that VM 4.2 supports PFAULT but has a bug in its
844 implementation that causes some problems.
845 Everybody who wants to run Linux under VM != VM4.2 should select
846 this option.
847
1da177e4 848config CMM
6f9a3c33
MS
849 def_tristate n
850 prompt "Cooperative memory management"
1da177e4
LT
851 help
852 Select this option, if you want to enable the kernel interface
853 to reduce the memory size of the system. This is accomplished
854 by allocating pages of memory and put them "on hold". This only
855 makes sense for a system running under VM where the unused pages
856 will be reused by VM for other guest systems. The interface
857 allows an external monitor to balance memory of many systems.
858 Everybody who wants to run Linux under VM should select this
859 option.
860
1da177e4 861config CMM_IUCV
6f9a3c33
MS
862 def_bool y
863 prompt "IUCV special message interface to cooperative memory management"
1da177e4
LT
864 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
865 help
866 Select this option to enable the special message interface to
867 the cooperative memory management.
868
1da177e4 869config APPLDATA_BASE
6f9a3c33
MS
870 def_bool n
871 prompt "Linux - VM Monitor Stream, base infrastructure"
c185b783 872 depends on PROC_FS
1da177e4
LT
873 help
874 This provides a kernel interface for creating and updating z/VM APPLDATA
875 monitor records. The monitor records are updated at certain time
876 intervals, once the timer is started.
877 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
878 i.e. enables or disables monitoring on the Linux side.
879 A custom interval value (in seconds) can be written to
880 /proc/appldata/interval.
881
882 Defaults are 60 seconds interval and timer off.
883 The /proc entries can also be read from, showing the current settings.
884
885config APPLDATA_MEM
6f9a3c33
MS
886 def_tristate m
887 prompt "Monitor memory management statistics"
62fb2ba3 888 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
1da177e4
LT
889 help
890 This provides memory management related data to the Linux - VM Monitor
891 Stream, like paging/swapping rate, memory utilisation, etc.
892 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
893 APPLDATA monitor record, i.e. enables or disables monitoring this record
894 on the z/VM side.
895
896 Default is disabled.
897 The /proc entry can also be read from, showing the current settings.
898
899 This can also be compiled as a module, which will be called
900 appldata_mem.o.
901
902config APPLDATA_OS
6f9a3c33
MS
903 def_tristate m
904 prompt "Monitor OS statistics"
1da177e4
LT
905 depends on APPLDATA_BASE
906 help
907 This provides OS related data to the Linux - VM Monitor Stream, like
908 CPU utilisation, etc.
909 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
910 APPLDATA monitor record, i.e. enables or disables monitoring this record
911 on the z/VM side.
912
913 Default is disabled.
914 This can also be compiled as a module, which will be called
915 appldata_os.o.
916
917config APPLDATA_NET_SUM
6f9a3c33
MS
918 def_tristate m
919 prompt "Monitor overall network statistics"
70193af9 920 depends on APPLDATA_BASE && NET
1da177e4
LT
921 help
922 This provides network related data to the Linux - VM Monitor Stream,
923 currently there is only a total sum of network I/O statistics, no
924 per-interface data.
925 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
926 APPLDATA monitor record, i.e. enables or disables monitoring this record
927 on the z/VM side.
928
929 Default is disabled.
930 This can also be compiled as a module, which will be called
931 appldata_net_sum.o.
932
24bbb1fa 933config S390_HYPFS_FS
6f9a3c33
MS
934 def_bool y
935 prompt "s390 hypervisor file system support"
24bbb1fa 936 select SYS_HYPERVISOR
24bbb1fa
MH
937 help
938 This is a virtual file system intended to provide accounting
939 information in an s390 hypervisor environment.
940
843c48fd 941source "arch/s390/kvm/Kconfig"
411ed322 942
fa587743 943config S390_GUEST
6f9a3c33 944 def_bool y
510cf5a6 945 prompt "s390 support for virtio devices"
79b6f7fb 946 select TTY
80629b0b 947 select VIRTUALIZATION
fa587743 948 select VIRTIO
faeba830 949 select VIRTIO_CONSOLE
fa587743 950 help
bdd1fc27
CH
951 Enabling this option adds support for virtio based paravirtual device
952 drivers on s390.
1da177e4 953
20766c08 954 Select this option if you want to run the kernel as a guest under
bdd1fc27 955 the KVM hypervisor.
155af2f9
HJP
956
957endmenu