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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
eca577ef 38config ARCH_DMA_ADDR_T_64BIT
5a79859a 39 def_bool y
eca577ef 40
b6b40c53 41config GENERIC_LOCKBREAK
6f9a3c33 42 def_bool y if SMP && PREEMPT
b6b40c53 43
402b0862 44config PGSTE
6f9a3c33 45 def_bool y if KVM
402b0862 46
6a11f75b
AM
47config ARCH_SUPPORTS_DEBUG_PAGEALLOC
48 def_bool y
49
843c48fd
JG
50config KEXEC
51 def_bool y
2965faa5 52 select KEXEC_CORE
843c48fd
JG
53
54config AUDIT_ARCH
55 def_bool y
56
ce816fa8 57config NO_IOPORT_MAP
c8717a3d
JG
58 def_bool y
59
60config PCI_QUIRKS
61 def_bool n
62
2a0a5b22 63config ARCH_SUPPORTS_UPROBES
5a79859a 64 def_bool y
2a0a5b22 65
347a8dc3 66config S390
61d48c2c 67 def_bool y
23fefe11 68 select ARCH_BINFMT_ELF_STATE
21266be9 69 select ARCH_HAS_DEVMEM_IS_ALLOWED
2b68f6ca 70 select ARCH_HAS_ELF_RANDOMIZE
79962038 71 select ARCH_HAS_FORTIFY_SOURCE
957e3fac 72 select ARCH_HAS_GCOV_PROFILE_ALL
e1073d1e 73 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
907fa061 74 select ARCH_HAS_KCOV
d2852a22 75 select ARCH_HAS_SET_MEMORY
47523c98 76 select ARCH_HAS_SG_CHAIN
ad21fc4f
LA
77 select ARCH_HAS_STRICT_KERNEL_RWX
78 select ARCH_HAS_STRICT_MODULE_RWX
c42d8c7d 79 select ARCH_HAS_UBSAN_SANITIZE_ALL
0e0d04a8 80 select ARCH_HAVE_NMI_SAFE_CMPXCHG
6beb0009
TG
81 select ARCH_INLINE_READ_LOCK
82 select ARCH_INLINE_READ_LOCK_BH
83 select ARCH_INLINE_READ_LOCK_IRQ
84 select ARCH_INLINE_READ_LOCK_IRQSAVE
0e0d04a8 85 select ARCH_INLINE_READ_TRYLOCK
6beb0009
TG
86 select ARCH_INLINE_READ_UNLOCK
87 select ARCH_INLINE_READ_UNLOCK_BH
88 select ARCH_INLINE_READ_UNLOCK_IRQ
89 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
0e0d04a8
HC
90 select ARCH_INLINE_SPIN_LOCK
91 select ARCH_INLINE_SPIN_LOCK_BH
92 select ARCH_INLINE_SPIN_LOCK_IRQ
93 select ARCH_INLINE_SPIN_LOCK_IRQSAVE
94 select ARCH_INLINE_SPIN_TRYLOCK
95 select ARCH_INLINE_SPIN_TRYLOCK_BH
96 select ARCH_INLINE_SPIN_UNLOCK
97 select ARCH_INLINE_SPIN_UNLOCK_BH
98 select ARCH_INLINE_SPIN_UNLOCK_IRQ
99 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
6beb0009
TG
100 select ARCH_INLINE_WRITE_LOCK
101 select ARCH_INLINE_WRITE_LOCK_BH
102 select ARCH_INLINE_WRITE_LOCK_IRQ
103 select ARCH_INLINE_WRITE_LOCK_IRQSAVE
0e0d04a8 104 select ARCH_INLINE_WRITE_TRYLOCK
6beb0009
TG
105 select ARCH_INLINE_WRITE_UNLOCK
106 select ARCH_INLINE_WRITE_UNLOCK_BH
107 select ARCH_INLINE_WRITE_UNLOCK_IRQ
108 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
0e0d04a8 109 select ARCH_SAVE_PAGE_KEYS if HIBERNATION
36e7fdaa 110 select ARCH_SUPPORTS_ATOMIC_RMW
fd15a1f3 111 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
a763bc8b 112 select ARCH_SUPPORTS_NUMA_BALANCING
295d8fa9 113 select ARCH_USE_BUILTIN_BSWAP
efc1d23b 114 select ARCH_USE_CMPXCHG_LOCKREF
3f6813b9 115 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
a763bc8b 116 select ARCH_WANTS_PROT_NUMA_PROT_NONE
c42d8c7d 117 select ARCH_WANTS_UBSAN_NO_NULL
c1d7e01d 118 select ARCH_WANT_IPC_PARSE_VERSION
0e0d04a8
HC
119 select BUILDTIME_EXTABLE_SORT
120 select CLONE_BACKWARDS2
5d6a0163 121 select DYNAMIC_FTRACE if FUNCTION_TRACER
0e0d04a8 122 select GENERIC_CLOCKEVENTS
8f00b3e2 123 select GENERIC_CPU_AUTOPROBE
0e0d04a8 124 select GENERIC_CPU_DEVICES if !SMP
1f7ab7ad 125 select GENERIC_CPU_VULNERABILITIES
746479cd 126 select GENERIC_FIND_FIRST_BIT
e80e7813 127 select GENERIC_SMP_IDLE_THREAD
79c74ecb 128 select GENERIC_TIME_VSYSCALL
0e0d04a8 129 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
7a017721 130 select HAVE_ARCH_AUDITSYSCALL
5a79859a 131 select HAVE_ARCH_JUMP_LABEL
fff7fb0b 132 select CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES
c63cb468 133 select HAVE_ARCH_SECCOMP_FILTER
5614dd92 134 select HAVE_ARCH_SOFT_DIRTY
0e0d04a8 135 select HAVE_ARCH_TRACEHOOK
5a79859a 136 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
6077776b 137 select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
0e0d04a8
HC
138 select HAVE_CMPXCHG_DOUBLE
139 select HAVE_CMPXCHG_LOCAL
f50c0e63 140 select HAVE_COPY_THREAD_TLS
0e0d04a8 141 select HAVE_DEBUG_KMEMLEAK
e82becfc 142 select HAVE_DMA_API_DEBUG
e1231b0e 143 select HAVE_DMA_CONTIGUOUS
7844572c 144 select DMA_NOOP_OPS
5a79859a
HC
145 select HAVE_DYNAMIC_FTRACE
146 select HAVE_DYNAMIC_FTRACE_WITH_REGS
9078a549 147 select HAVE_EFFICIENT_UNALIGNED_ACCESS
0e0d04a8 148 select HAVE_FTRACE_MCOUNT_RECORD
5a79859a
HC
149 select HAVE_FUNCTION_GRAPH_TRACER
150 select HAVE_FUNCTION_TRACER
03b8c7b6 151 select HAVE_FUTEX_CMPXCHG if FUTEX
dfd4c493 152 select HAVE_GCC_PLUGINS
0e0d04a8
HC
153 select HAVE_KERNEL_BZIP2
154 select HAVE_KERNEL_GZIP
8e2872ce 155 select HAVE_KERNEL_LZ4
0e0d04a8
HC
156 select HAVE_KERNEL_LZMA
157 select HAVE_KERNEL_LZO
158 select HAVE_KERNEL_XZ
159 select HAVE_KPROBES
160 select HAVE_KRETPROBES
5a79859a 161 select HAVE_KVM
21042d43 162 select HAVE_LIVEPATCH
c33eff60
HC
163 select HAVE_PERF_REGS
164 select HAVE_PERF_USER_STACK_DUMP
0e0d04a8
HC
165 select HAVE_MEMBLOCK
166 select HAVE_MEMBLOCK_NODE_MAP
50be6345 167 select HAVE_MEMBLOCK_PHYS_MAP
786d35d4 168 select HAVE_MOD_ARCH_SPECIFIC
0e0d04a8
HC
169 select HAVE_OPROFILE
170 select HAVE_PERF_EVENTS
171 select HAVE_REGS_AND_STACK_ACCESS_API
172 select HAVE_SYSCALL_TRACEPOINTS
0e0d04a8 173 select HAVE_VIRT_CPU_ACCOUNTING
786d35d4 174 select MODULES_USE_ELF_RELA
50be6345 175 select NO_BOOTMEM
7eddd99c 176 select OLD_SIGACTION
93bead43 177 select OLD_SIGSUSPEND3
bb98f396 178 select SPARSE_IRQ
0e0d04a8 179 select SYSCTL_EXCEPTION_TRACE
d5c352cd 180 select THREAD_INFO_IN_TASK
0563416b 181 select TTY
0e0d04a8 182 select VIRT_CPU_ACCOUNTING
40565b5a 183 select ARCH_HAS_SCALED_CPUTIME
93bead43 184 select VIRT_TO_BUS
42a0bb3f 185 select HAVE_NMI
3a368f74 186
1da177e4 187
fca3e357 188config SCHED_OMIT_FRAME_POINTER
6f9a3c33 189 def_bool y
fca3e357 190
c81956c9
KS
191config PGTABLE_LEVELS
192 int
1aea9b3f 193 default 5
c81956c9 194
1da177e4
LT
195source "init/Kconfig"
196
dc52ddc0
MH
197source "kernel/Kconfig.freezer"
198
21042d43
JS
199source "kernel/livepatch/Kconfig"
200
843c48fd
JG
201menu "Processor type and features"
202
203config HAVE_MARCH_Z900_FEATURES
204 def_bool n
205
206config HAVE_MARCH_Z990_FEATURES
207 def_bool n
208 select HAVE_MARCH_Z900_FEATURES
209
210config HAVE_MARCH_Z9_109_FEATURES
211 def_bool n
212 select HAVE_MARCH_Z990_FEATURES
213
214config HAVE_MARCH_Z10_FEATURES
215 def_bool n
216 select HAVE_MARCH_Z9_109_FEATURES
217
218config HAVE_MARCH_Z196_FEATURES
219 def_bool n
220 select HAVE_MARCH_Z10_FEATURES
221
991c1505
HC
222config HAVE_MARCH_ZEC12_FEATURES
223 def_bool n
224 select HAVE_MARCH_Z196_FEATURES
225
f8b2dcbd
MS
226config HAVE_MARCH_Z13_FEATURES
227 def_bool n
228 select HAVE_MARCH_ZEC12_FEATURES
229
6997c323
MS
230config HAVE_MARCH_Z14_FEATURES
231 def_bool n
232 select HAVE_MARCH_Z13_FEATURES
233
843c48fd
JG
234choice
235 prompt "Processor type"
7072276e 236 default MARCH_Z196
1da177e4 237
843c48fd
JG
238config MARCH_Z900
239 bool "IBM zSeries model z800 and z900"
5a79859a 240 select HAVE_MARCH_Z900_FEATURES
843c48fd
JG
241 help
242 Select this to enable optimizations for model z800/z900 (2064 and
243 2066 series). This will enable some optimizations that are not
244 available on older ESA/390 (31 Bit) only CPUs.
245
246config MARCH_Z990
247 bool "IBM zSeries model z890 and z990"
5a79859a 248 select HAVE_MARCH_Z990_FEATURES
843c48fd
JG
249 help
250 Select this to enable optimizations for model z890/z990 (2084 and
251 2086 series). The kernel will be slightly faster but will not work
252 on older machines.
253
254config MARCH_Z9_109
255 bool "IBM System z9"
5a79859a 256 select HAVE_MARCH_Z9_109_FEATURES
843c48fd
JG
257 help
258 Select this to enable optimizations for IBM System z9 (2094 and
259 2096 series). The kernel will be slightly faster but will not work
260 on older machines.
261
262config MARCH_Z10
263 bool "IBM System z10"
5a79859a 264 select HAVE_MARCH_Z10_FEATURES
843c48fd
JG
265 help
266 Select this to enable optimizations for IBM System z10 (2097 and
267 2098 series). The kernel will be slightly faster but will not work
268 on older machines.
269
270config MARCH_Z196
271 bool "IBM zEnterprise 114 and 196"
5a79859a 272 select HAVE_MARCH_Z196_FEATURES
843c48fd
JG
273 help
274 Select this to enable optimizations for IBM zEnterprise 114 and 196
275 (2818 and 2817 series). The kernel will be slightly faster but will
276 not work on older machines.
1da177e4 277
991c1505 278config MARCH_ZEC12
59471227 279 bool "IBM zBC12 and zEC12"
5a79859a 280 select HAVE_MARCH_ZEC12_FEATURES
991c1505 281 help
59471227
HC
282 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
283 2827 series). The kernel will be slightly faster but will not work on
284 older machines.
991c1505 285
f8b2dcbd 286config MARCH_Z13
bb3aa614 287 bool "IBM z13s and z13"
5a79859a 288 select HAVE_MARCH_Z13_FEATURES
f8b2dcbd 289 help
bb3aa614
HC
290 Select this to enable optimizations for IBM z13s and z13 (2965 and
291 2964 series). The kernel will be slightly faster but will not work on
292 older machines.
f8b2dcbd 293
6997c323 294config MARCH_Z14
734fce8d 295 bool "IBM z14 ZR1 and z14"
6997c323
MS
296 select HAVE_MARCH_Z14_FEATURES
297 help
734fce8d
HC
298 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
299 and 3906 series). The kernel will be slightly faster but will not
300 work on older machines.
6997c323 301
843c48fd 302endchoice
1da177e4 303
1db9e051
HC
304config MARCH_Z900_TUNE
305 def_bool TUNE_Z900 || MARCH_Z900 && TUNE_DEFAULT
306
307config MARCH_Z990_TUNE
308 def_bool TUNE_Z990 || MARCH_Z990 && TUNE_DEFAULT
309
310config MARCH_Z9_109_TUNE
311 def_bool TUNE_Z9_109 || MARCH_Z9_109 && TUNE_DEFAULT
312
313config MARCH_Z10_TUNE
314 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
315
316config MARCH_Z196_TUNE
317 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
318
319config MARCH_ZEC12_TUNE
320 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
321
f8b2dcbd
MS
322config MARCH_Z13_TUNE
323 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
324
6997c323
MS
325config MARCH_Z14_TUNE
326 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
327
1db9e051
HC
328choice
329 prompt "Tune code generation"
330 default TUNE_DEFAULT
331 help
332 Cause the compiler to tune (-mtune) the generated code for a machine.
333 This will make the code run faster on the selected machine but
334 somewhat slower on other machines.
335 This option only changes how the compiler emits instructions, not the
336 selection of instructions itself, so the resulting kernel will run on
337 all other machines.
338
339config TUNE_DEFAULT
340 bool "Default"
341 help
342 Tune the generated code for the target processor for which the kernel
343 will be compiled.
344
1db9e051
HC
345config TUNE_Z900
346 bool "IBM zSeries model z800 and z900"
347
348config TUNE_Z990
349 bool "IBM zSeries model z890 and z990"
350
351config TUNE_Z9_109
352 bool "IBM System z9"
353
354config TUNE_Z10
355 bool "IBM System z10"
356
357config TUNE_Z196
358 bool "IBM zEnterprise 114 and 196"
359
360config TUNE_ZEC12
361 bool "IBM zBC12 and zEC12"
362
f8b2dcbd
MS
363config TUNE_Z13
364 bool "IBM z13"
365
6997c323
MS
366config TUNE_Z14
367 bool "IBM z14"
368
1db9e051
HC
369endchoice
370
347a8dc3 371config 64BIT
6f9a3c33 372 def_bool y
d9f7a745 373
843c48fd
JG
374config COMPAT
375 def_bool y
376 prompt "Kernel support for 31 bit emulation"
843c48fd
JG
377 select COMPAT_BINFMT_ELF if BINFMT_ELF
378 select ARCH_WANT_OLD_COMPAT_IPC
7eddd99c 379 select COMPAT_OLD_SIGACTION
2813893f 380 depends on MULTIUSER
843c48fd
JG
381 help
382 Select this option if you want to enable your system kernel to
383 handle system-calls from ELF binaries for 31 bit ESA. This option
384 (and some other stuff like libraries and such) is needed for
385 executing 31 bit applications. It is safe to say "Y".
386
387config SYSVIPC_COMPAT
388 def_bool y if COMPAT && SYSVIPC
389
1da177e4 390config SMP
6f9a3c33
MS
391 def_bool y
392 prompt "Symmetric multi-processing support"
1da177e4
LT
393 ---help---
394 This enables support for systems with more than one CPU. If you have
395 a system with only one CPU, like most personal computers, say N. If
396 you have a system with more than one CPU, say Y.
397
4a474157 398 If you say N here, the kernel will run on uni- and multiprocessor
1da177e4
LT
399 machines, but will use only one CPU of a multiprocessor machine. If
400 you say Y here, the kernel will run on many, but not all,
4a474157 401 uniprocessor machines. On a uniprocessor machine, the kernel
1da177e4
LT
402 will run faster if you say N here.
403
03502faa
AB
404 See also the SMP-HOWTO available at
405 <http://www.tldp.org/docs.html#howto>.
1da177e4
LT
406
407 Even if you don't know what to do here, say Y.
408
409config NR_CPUS
5c75a0da
HC
410 int "Maximum number of CPUs (2-512)"
411 range 2 512
1da177e4 412 depends on SMP
5a79859a 413 default "64"
1da177e4
LT
414 help
415 This allows you to specify the maximum number of CPUs which this
5c75a0da 416 kernel will support. The maximum supported value is 512 and the
1da177e4
LT
417 minimum value which makes sense is 2.
418
419 This is purely to save memory - each supported CPU adds
420 approximately sixteen kilobytes to the kernel image.
421
422config HOTPLUG_CPU
6f9a3c33
MS
423 def_bool y
424 prompt "Support for hot-pluggable CPUs"
1da177e4 425 depends on SMP
1da177e4
LT
426 help
427 Say Y here to be able to turn CPUs off and on. CPUs
428 can be controlled through /sys/devices/system/cpu/cpu#.
429 Say N if you want to disable CPU hotplug.
430
3a368f74
PH
431# Some NUMA nodes have memory ranges that span
432# other nodes. Even though a pfn is valid and
433# between a node's start and end pfns, it may not
434# reside on that node. See memmap_init_zone()
435# for details. <- They meant memory holes!
436config NODES_SPAN_OTHER_NODES
437 def_bool NUMA
438
439config NUMA
440 bool "NUMA support"
c095a949 441 depends on SMP && SCHED_TOPOLOGY
3a368f74
PH
442 default n
443 help
444 Enable NUMA support
445
446 This option adds NUMA support to the kernel.
447
448 An operation mode can be selected by appending
449 numa=<method> to the kernel command line.
450
451 The default behaviour is identical to appending numa=plain to
452 the command line. This will create just one node with all
453 available memory and all CPUs in it.
454
455config NODES_SHIFT
456 int "Maximum NUMA nodes (as a power of 2)"
457 range 1 10
458 depends on NUMA
459 default "4"
460 help
461 Specify the maximum number of NUMA nodes available on the target
462 system. Increases memory reserved to accommodate various tables.
463
c29a7baf
MH
464menu "Select NUMA modes"
465 depends on NUMA
466
467config NUMA_EMU
468 bool "NUMA emulation"
469 default y
470 help
471 Numa emulation mode will split the available system memory into
472 equal chunks which then are distributed over the configured number
473 of nodes in a round-robin manner.
474
475 The number of fake nodes is limited by the number of available memory
476 chunks (i.e. memory size / fake size) and the number of supported
477 nodes in the kernel.
478
479 The CPUs are assigned to the nodes in a way that partially respects
480 the original machine topology (if supported by the machine).
481 Fair distribution of the CPUs is not guaranteed.
482
483config EMU_SIZE
484 hex "NUMA emulation memory chunk size"
485 default 0x10000000
486 range 0x400000 0x100000000
487 depends on NUMA_EMU
488 help
489 Select the default size by which the memory is chopped and then
490 assigned to emulated NUMA nodes.
491
492 This can be overridden by specifying
493
494 emu_size=<n>
495
496 on the kernel command line where also suffixes K, M, G, and T are
497 supported.
498
499endmenu
9236b4dd
HC
500
501config SCHED_SMT
502 def_bool n
c29a7baf 503
8d11e021 504config SCHED_MC
83a24e32 505 def_bool n
8d11e021 506
4cb14bc8 507config SCHED_BOOK
10ad34bc
MS
508 def_bool n
509
adac0f1e
HC
510config SCHED_DRAWER
511 def_bool n
512
10ad34bc 513config SCHED_TOPOLOGY
6f9a3c33 514 def_bool y
10ad34bc 515 prompt "Topology scheduler support"
83a24e32 516 depends on SMP
10ad34bc 517 select SCHED_SMT
83a24e32 518 select SCHED_MC
10ad34bc 519 select SCHED_BOOK
adac0f1e 520 select SCHED_DRAWER
4cb14bc8 521 help
10ad34bc
MS
522 Topology scheduler support improves the CPU scheduler's decision
523 making when dealing with machines that have multi-threading,
524 multiple cores or multiple books.
4cb14bc8 525
843c48fd
JG
526source kernel/Kconfig.preempt
527
843c48fd 528source kernel/Kconfig.hz
1da177e4 529
4c637cd8
HF
530config ARCH_RANDOM
531 def_bool y
532 prompt "s390 architectural random number generation API"
533 help
534 Enable the s390 architectural random number generation API
535 to provide random data for all consumers within the Linux
536 kernel.
537
538 When enabled the arch_random_* functions declared in linux/random.h
539 are implemented. The implementation is based on the s390 CPACF
540 instruction subfunction TRNG which provides a real true random
541 number generator.
542
543 If unsure, say Y.
544
92fa2703
MS
545config KERNEL_NOBP
546 def_bool n
547 prompt "Enable modified branch prediction for the kernel by default"
548 help
549 If this option is selected the kernel will switch to a modified
550 branch prediction mode if the firmware interface is available.
551 The modified branch prediction mode improves the behaviour in
552 regard to speculative execution.
553
554 With the option enabled the kernel parameter "nobp=0" or "nospec"
555 can be used to run the kernel in the normal branch prediction mode.
556
557 With the option disabled the modified branch prediction mode is
558 enabled with the "nobp=1" kernel parameter.
559
560 If unsure, say N.
561
00d54225
MS
562config EXPOLINE
563 def_bool n
564 prompt "Avoid speculative indirect branches in the kernel"
565 help
566 Compile the kernel with the expoline compiler options to guard
567 against kernel-to-user data leaks by avoiding speculative indirect
568 branches.
569 Requires a compiler with -mindirect-branch=thunk support for full
570 protection. The kernel may run slower.
571
572 If unsure, say N.
573
574choice
575 prompt "Expoline default"
576 depends on EXPOLINE
577 default EXPOLINE_FULL
578
579config EXPOLINE_OFF
580 bool "spectre_v2=off"
581
3eb01835 582config EXPOLINE_AUTO
00d54225
MS
583 bool "spectre_v2=auto"
584
585config EXPOLINE_FULL
586 bool "spectre_v2=on"
587
588endchoice
589
843c48fd 590endmenu
1da177e4 591
843c48fd 592menu "Memory setup"
1d057720 593
843c48fd 594config ARCH_SPARSEMEM_ENABLE
6f9a3c33 595 def_bool y
843c48fd
JG
596 select SPARSEMEM_VMEMMAP_ENABLE
597 select SPARSEMEM_VMEMMAP
e65e1fc2 598
843c48fd
JG
599config ARCH_SPARSEMEM_DEFAULT
600 def_bool y
1da177e4 601
843c48fd
JG
602config ARCH_SELECT_MEMORY_MODEL
603 def_bool y
1da177e4 604
843c48fd
JG
605config ARCH_ENABLE_MEMORY_HOTPLUG
606 def_bool y if SPARSEMEM
0efa4703 607
843c48fd
JG
608config ARCH_ENABLE_MEMORY_HOTREMOVE
609 def_bool y
e37f50e1 610
ec66ad66
MS
611config ARCH_ENABLE_SPLIT_PMD_PTLOCK
612 def_bool y
ec66ad66 613
843c48fd
JG
614config FORCE_MAX_ZONEORDER
615 int
616 default "9"
f861e405 617
843c48fd 618source "mm/Kconfig"
1da177e4 619
b8402b95
HC
620config MAX_PHYSMEM_BITS
621 int "Maximum size of supported physical memory in bits (42-53)"
622 range 42 53
623 default "46"
624 help
625 This option specifies the maximum supported size of physical memory
626 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
627 Increasing the number of bits also increases the kernel image size.
628 By default 46 bits (64TB) are supported.
629
1da177e4 630config PACK_STACK
6f9a3c33
MS
631 def_bool y
632 prompt "Pack kernel stack"
1da177e4
LT
633 help
634 This option enables the compiler option -mkernel-backchain if it
635 is available. If the option is available the compiler supports
636 the new stack layout which dramatically reduces the minimum stack
637 frame size. With an old compiler a non-leaf function needs a
638 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
639 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
640 and 24 byte on 64 bit.
641
642 Say Y if you are unsure.
643
1da177e4 644config CHECK_STACK
6f9a3c33
MS
645 def_bool y
646 prompt "Detect kernel stack overflow"
1da177e4
LT
647 help
648 This option enables the compiler option -mstack-guard and
649 -mstack-size if they are available. If the compiler supports them
650 it will emit additional code to each function prolog to trigger
651 an illegal operation if the kernel stack is about to overflow.
652
653 Say N if you are unsure.
654
655config STACK_GUARD
656 int "Size of the guard area (128-1024)"
657 range 128 1024
658 depends on CHECK_STACK
659 default "256"
660 help
661 This allows you to specify the size of the guard area at the lower
662 end of the kernel stack. If the kernel stack points into the guard
663 area on function entry an illegal operation is triggered. The size
664 needs to be a power of 2. Please keep in mind that the size of an
665 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
666 The minimum size for the stack guard should be 256 for 31 bit and
667 512 for 64 bit.
668
2c190da4 669config WARN_DYNAMIC_STACK
6f9a3c33 670 def_bool n
2c190da4 671 prompt "Emit compiler warnings for function with dynamic stack usage"
1da177e4 672 help
2c190da4
JG
673 This option enables the compiler option -mwarn-dynamicstack. If the
674 compiler supports this options generates warnings for functions
675 that dynamically allocate stack space using alloca.
1da177e4
LT
676
677 Say N if you are unsure.
678
843c48fd 679endmenu
3f22ab27 680
843c48fd 681menu "I/O subsystem"
1da177e4 682
1da177e4 683config QDIO
6f9a3c33
MS
684 def_tristate y
685 prompt "QDIO support"
1da177e4 686 ---help---
8129ee16 687 This driver provides the Queued Direct I/O base support for
efca13bc 688 IBM System z.
1da177e4
LT
689
690 To compile this driver as a module, choose M here: the
691 module will be called qdio.
692
693 If unsure, say Y.
694
c8717a3d
JG
695menuconfig PCI
696 bool "PCI support"
c8717a3d 697 select PCI_MSI
8128f23c 698 select IOMMU_SUPPORT
c8717a3d
JG
699 help
700 Enable PCI support.
701
702if PCI
703
704config PCI_NR_FUNCTIONS
705 int "Maximum number of PCI functions (1-4096)"
706 range 1 4096
b18601b0 707 default "128"
c8717a3d
JG
708 help
709 This allows you to specify the maximum number of PCI functions which
710 this kernel will support.
711
712source "drivers/pci/Kconfig"
c8717a3d
JG
713
714endif # PCI
715
716config PCI_DOMAINS
717 def_bool PCI
718
719config HAS_IOMEM
720 def_bool PCI
721
722config IOMMU_HELPER
723 def_bool PCI
724
c8717a3d
JG
725config NEED_SG_DMA_LENGTH
726 def_bool PCI
727
91630032
JG
728config NEED_DMA_MAP_STATE
729 def_bool PCI
730
9d92a7e1 731config CHSC_SCH
d9c11b1e 732 def_tristate m
6f9a3c33 733 prompt "Support for CHSC subchannels"
9d92a7e1
CH
734 help
735 This driver allows usage of CHSC subchannels. A CHSC subchannel
736 is usually present on LPAR only.
737 The driver creates a device /dev/chsc, which may be used to
738 obtain I/O configuration information about the machine and
739 to issue asynchronous chsc commands (DANGEROUS).
740 You will usually only want to use this interface on a special
741 LPAR designated for system management.
742
743 To compile this driver as a module, choose M here: the
744 module will be called chsc_sch.
745
746 If unsure, say N.
747
1d1c8f78
SO
748config SCM_BUS
749 def_bool y
1d1c8f78
SO
750 prompt "SCM bus driver"
751 help
752 Bus driver for Storage Class Memory.
753
eadb86ab
SO
754config EADM_SCH
755 def_tristate m
756 prompt "Support for EADM subchannels"
757 depends on SCM_BUS
758 help
759 This driver allows usage of EADM subchannels. EADM subchannels act
760 as a communication vehicle for SCM increments.
761
762 To compile this driver as a module, choose M here: the
763 module will be called eadm_sch.
764
63f1934d
DJS
765config VFIO_CCW
766 def_tristate n
767 prompt "Support for VFIO-CCW subchannels"
84cd8fc4 768 depends on S390_CCW_IOMMU && VFIO_MDEV
63f1934d
DJS
769 help
770 This driver allows usage of I/O subchannels via VFIO-CCW.
771
772 To compile this driver as a module, choose M here: the
773 module will be called vfio_ccw.
774
d85abf4c
TK
775config VFIO_AP
776 def_tristate n
777 prompt "VFIO support for AP devices"
778 depends on S390_AP_IOMMU && VFIO_MDEV_DEVICE && KVM
779 help
780 This driver grants access to Adjunct Processor (AP) devices
781 via the VFIO mediated device interface.
782
783 To compile this driver as a module, choose M here: the module
784 will be called vfio_ap.
785
843c48fd
JG
786endmenu
787
788menu "Dump support"
789
790config CRASH_DUMP
791 bool "kernel crash dumps"
5a79859a 792 depends on SMP
843c48fd
JG
793 select KEXEC
794 help
795 Generate crash dump after being started by kexec.
796 Crash dump kernels are loaded in the main kernel with kexec-tools
797 into a specially reserved region and then later executed after
798 a crash by kdump/kexec.
843c48fd 799 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
bf28a597
MH
800 This option also enables s390 zfcpdump.
801 See also <file:Documentation/s390/zfcpdump.txt>
843c48fd
JG
802
803endmenu
804
805menu "Executable file formats / Emulations"
1da177e4 806
1da177e4
LT
807source "fs/Kconfig.binfmt"
808
843c48fd
JG
809config SECCOMP
810 def_bool y
811 prompt "Enable seccomp to safely compute untrusted bytecode"
812 depends on PROC_FS
813 help
814 This kernel feature is useful for number crunching applications
815 that may need to compute untrusted bytecode during their
816 execution. By using pipes or other transports made available to
817 the process as file descriptors supporting the read/write
818 syscalls, it's possible to isolate those applications in
819 their own address space using seccomp. Once seccomp is
820 enabled via /proc/<pid>/seccomp, it cannot be disabled
821 and the task is only allowed to execute a few safe syscalls
822 defined by each seccomp mode.
823
824 If unsure, say Y.
825
826endmenu
827
828menu "Power Management"
829
830config ARCH_HIBERNATION_POSSIBLE
5a79859a 831 def_bool y
843c48fd
JG
832
833source "kernel/power/Kconfig"
834
835endmenu
836
837source "net/Kconfig"
838
839config PCMCIA
840 def_bool n
841
842config CCW
843 def_bool y
844
845source "drivers/Kconfig"
846
847source "fs/Kconfig"
848
849source "arch/s390/Kconfig.debug"
850
851source "security/Kconfig"
852
853source "crypto/Kconfig"
854
855source "lib/Kconfig"
856
857menu "Virtualization"
684de39b 858
1da177e4 859config PFAULT
6f9a3c33
MS
860 def_bool y
861 prompt "Pseudo page fault support"
1da177e4
LT
862 help
863 Select this option, if you want to use PFAULT pseudo page fault
864 handling under VM. If running native or in LPAR, this option
865 has no effect. If your VM does not support PFAULT, PAGEEX
866 pseudo page fault handling will be used.
867 Note that VM 4.2 supports PFAULT but has a bug in its
868 implementation that causes some problems.
869 Everybody who wants to run Linux under VM != VM4.2 should select
870 this option.
871
1da177e4 872config CMM
6f9a3c33
MS
873 def_tristate n
874 prompt "Cooperative memory management"
1da177e4
LT
875 help
876 Select this option, if you want to enable the kernel interface
877 to reduce the memory size of the system. This is accomplished
878 by allocating pages of memory and put them "on hold". This only
879 makes sense for a system running under VM where the unused pages
880 will be reused by VM for other guest systems. The interface
881 allows an external monitor to balance memory of many systems.
882 Everybody who wants to run Linux under VM should select this
883 option.
884
1da177e4 885config CMM_IUCV
6f9a3c33
MS
886 def_bool y
887 prompt "IUCV special message interface to cooperative memory management"
1da177e4
LT
888 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
889 help
890 Select this option to enable the special message interface to
891 the cooperative memory management.
892
1da177e4 893config APPLDATA_BASE
6f9a3c33
MS
894 def_bool n
895 prompt "Linux - VM Monitor Stream, base infrastructure"
c185b783 896 depends on PROC_FS
1da177e4
LT
897 help
898 This provides a kernel interface for creating and updating z/VM APPLDATA
899 monitor records. The monitor records are updated at certain time
900 intervals, once the timer is started.
901 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
902 i.e. enables or disables monitoring on the Linux side.
903 A custom interval value (in seconds) can be written to
904 /proc/appldata/interval.
905
906 Defaults are 60 seconds interval and timer off.
907 The /proc entries can also be read from, showing the current settings.
908
909config APPLDATA_MEM
6f9a3c33
MS
910 def_tristate m
911 prompt "Monitor memory management statistics"
62fb2ba3 912 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
1da177e4
LT
913 help
914 This provides memory management related data to the Linux - VM Monitor
915 Stream, like paging/swapping rate, memory utilisation, etc.
916 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
917 APPLDATA monitor record, i.e. enables or disables monitoring this record
918 on the z/VM side.
919
920 Default is disabled.
921 The /proc entry can also be read from, showing the current settings.
922
923 This can also be compiled as a module, which will be called
924 appldata_mem.o.
925
926config APPLDATA_OS
6f9a3c33
MS
927 def_tristate m
928 prompt "Monitor OS statistics"
1da177e4
LT
929 depends on APPLDATA_BASE
930 help
931 This provides OS related data to the Linux - VM Monitor Stream, like
932 CPU utilisation, etc.
933 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
934 APPLDATA monitor record, i.e. enables or disables monitoring this record
935 on the z/VM side.
936
937 Default is disabled.
938 This can also be compiled as a module, which will be called
939 appldata_os.o.
940
941config APPLDATA_NET_SUM
6f9a3c33
MS
942 def_tristate m
943 prompt "Monitor overall network statistics"
70193af9 944 depends on APPLDATA_BASE && NET
1da177e4
LT
945 help
946 This provides network related data to the Linux - VM Monitor Stream,
947 currently there is only a total sum of network I/O statistics, no
948 per-interface data.
949 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
950 APPLDATA monitor record, i.e. enables or disables monitoring this record
951 on the z/VM side.
952
953 Default is disabled.
954 This can also be compiled as a module, which will be called
955 appldata_net_sum.o.
956
24bbb1fa 957config S390_HYPFS_FS
6f9a3c33
MS
958 def_bool y
959 prompt "s390 hypervisor file system support"
24bbb1fa 960 select SYS_HYPERVISOR
24bbb1fa
MH
961 help
962 This is a virtual file system intended to provide accounting
963 information in an s390 hypervisor environment.
964
843c48fd 965source "arch/s390/kvm/Kconfig"
411ed322 966
fa587743 967config S390_GUEST
6f9a3c33 968 def_bool y
510cf5a6 969 prompt "s390 support for virtio devices"
79b6f7fb 970 select TTY
80629b0b 971 select VIRTUALIZATION
fa587743 972 select VIRTIO
faeba830 973 select VIRTIO_CONSOLE
fa587743 974 help
bdd1fc27
CH
975 Enabling this option adds support for virtio based paravirtual device
976 drivers on s390.
1da177e4 977
20766c08 978 Select this option if you want to run the kernel as a guest under
bdd1fc27 979 the KVM hypervisor.
155af2f9
HJP
980
981endmenu
c7664ddc
MS
982
983config KMSG_IDS
984 def_bool y
985 prompt "Kernel message numbers"
986 help
987 Select this option if you want to include a message number to the
988 prefix for kernel messages issued by the s390 architecture and
989 driver code. See "Documentation/s390/kmsg.txt" for more details.