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s390: add automatic detection of the spectre defense
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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
a763bc8b 111 select ARCH_SUPPORTS_NUMA_BALANCING
295d8fa9 112 select ARCH_USE_BUILTIN_BSWAP
efc1d23b 113 select ARCH_USE_CMPXCHG_LOCKREF
3f6813b9 114 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
c42d8c7d 115 select ARCH_WANTS_UBSAN_NO_NULL
c1d7e01d 116 select ARCH_WANT_IPC_PARSE_VERSION
0e0d04a8
HC
117 select BUILDTIME_EXTABLE_SORT
118 select CLONE_BACKWARDS2
5d6a0163 119 select DYNAMIC_FTRACE if FUNCTION_TRACER
0e0d04a8 120 select GENERIC_CLOCKEVENTS
8f00b3e2 121 select GENERIC_CPU_AUTOPROBE
0e0d04a8 122 select GENERIC_CPU_DEVICES if !SMP
746479cd 123 select GENERIC_FIND_FIRST_BIT
e80e7813 124 select GENERIC_SMP_IDLE_THREAD
79c74ecb 125 select GENERIC_TIME_VSYSCALL
0e0d04a8 126 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
7a017721 127 select HAVE_ARCH_AUDITSYSCALL
5a79859a 128 select HAVE_ARCH_JUMP_LABEL
fff7fb0b 129 select CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES
c63cb468 130 select HAVE_ARCH_SECCOMP_FILTER
5614dd92 131 select HAVE_ARCH_SOFT_DIRTY
0e0d04a8 132 select HAVE_ARCH_TRACEHOOK
5a79859a 133 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
6077776b 134 select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
0e0d04a8
HC
135 select HAVE_CMPXCHG_DOUBLE
136 select HAVE_CMPXCHG_LOCAL
f50c0e63 137 select HAVE_COPY_THREAD_TLS
0e0d04a8 138 select HAVE_DEBUG_KMEMLEAK
e82becfc 139 select HAVE_DMA_API_DEBUG
e1231b0e 140 select HAVE_DMA_CONTIGUOUS
002e6745 141 select DMA_DIRECT_OPS
5a79859a
HC
142 select HAVE_DYNAMIC_FTRACE
143 select HAVE_DYNAMIC_FTRACE_WITH_REGS
9078a549 144 select HAVE_EFFICIENT_UNALIGNED_ACCESS
0e0d04a8 145 select HAVE_FTRACE_MCOUNT_RECORD
5a79859a
HC
146 select HAVE_FUNCTION_GRAPH_TRACER
147 select HAVE_FUNCTION_TRACER
03b8c7b6 148 select HAVE_FUTEX_CMPXCHG if FUTEX
dfd4c493 149 select HAVE_GCC_PLUGINS
0e0d04a8
HC
150 select HAVE_KERNEL_BZIP2
151 select HAVE_KERNEL_GZIP
8e2872ce 152 select HAVE_KERNEL_LZ4
0e0d04a8
HC
153 select HAVE_KERNEL_LZMA
154 select HAVE_KERNEL_LZO
155 select HAVE_KERNEL_XZ
156 select HAVE_KPROBES
157 select HAVE_KRETPROBES
5a79859a 158 select HAVE_KVM
21042d43 159 select HAVE_LIVEPATCH
c33eff60
HC
160 select HAVE_PERF_REGS
161 select HAVE_PERF_USER_STACK_DUMP
0e0d04a8
HC
162 select HAVE_MEMBLOCK
163 select HAVE_MEMBLOCK_NODE_MAP
50be6345 164 select HAVE_MEMBLOCK_PHYS_MAP
786d35d4 165 select HAVE_MOD_ARCH_SPECIFIC
0e0d04a8
HC
166 select HAVE_OPROFILE
167 select HAVE_PERF_EVENTS
168 select HAVE_REGS_AND_STACK_ACCESS_API
169 select HAVE_SYSCALL_TRACEPOINTS
0e0d04a8 170 select HAVE_VIRT_CPU_ACCOUNTING
786d35d4 171 select MODULES_USE_ELF_RELA
50be6345 172 select NO_BOOTMEM
7eddd99c 173 select OLD_SIGACTION
93bead43 174 select OLD_SIGSUSPEND3
bb98f396 175 select SPARSE_IRQ
0e0d04a8 176 select SYSCTL_EXCEPTION_TRACE
d5c352cd 177 select THREAD_INFO_IN_TASK
0563416b 178 select TTY
0e0d04a8 179 select VIRT_CPU_ACCOUNTING
40565b5a 180 select ARCH_HAS_SCALED_CPUTIME
93bead43 181 select VIRT_TO_BUS
42a0bb3f 182 select HAVE_NMI
3a368f74 183
1da177e4 184
fca3e357 185config SCHED_OMIT_FRAME_POINTER
6f9a3c33 186 def_bool y
fca3e357 187
c81956c9
KS
188config PGTABLE_LEVELS
189 int
1aea9b3f 190 default 5
c81956c9 191
1da177e4
LT
192source "init/Kconfig"
193
dc52ddc0
MH
194source "kernel/Kconfig.freezer"
195
21042d43
JS
196source "kernel/livepatch/Kconfig"
197
843c48fd
JG
198menu "Processor type and features"
199
200config HAVE_MARCH_Z900_FEATURES
201 def_bool n
202
203config HAVE_MARCH_Z990_FEATURES
204 def_bool n
205 select HAVE_MARCH_Z900_FEATURES
206
207config HAVE_MARCH_Z9_109_FEATURES
208 def_bool n
209 select HAVE_MARCH_Z990_FEATURES
210
211config HAVE_MARCH_Z10_FEATURES
212 def_bool n
213 select HAVE_MARCH_Z9_109_FEATURES
214
215config HAVE_MARCH_Z196_FEATURES
216 def_bool n
217 select HAVE_MARCH_Z10_FEATURES
218
991c1505
HC
219config HAVE_MARCH_ZEC12_FEATURES
220 def_bool n
221 select HAVE_MARCH_Z196_FEATURES
222
f8b2dcbd
MS
223config HAVE_MARCH_Z13_FEATURES
224 def_bool n
225 select HAVE_MARCH_ZEC12_FEATURES
226
6997c323
MS
227config HAVE_MARCH_Z14_FEATURES
228 def_bool n
229 select HAVE_MARCH_Z13_FEATURES
230
843c48fd
JG
231choice
232 prompt "Processor type"
7072276e 233 default MARCH_Z196
1da177e4 234
843c48fd
JG
235config MARCH_Z900
236 bool "IBM zSeries model z800 and z900"
5a79859a 237 select HAVE_MARCH_Z900_FEATURES
843c48fd
JG
238 help
239 Select this to enable optimizations for model z800/z900 (2064 and
240 2066 series). This will enable some optimizations that are not
241 available on older ESA/390 (31 Bit) only CPUs.
242
243config MARCH_Z990
244 bool "IBM zSeries model z890 and z990"
5a79859a 245 select HAVE_MARCH_Z990_FEATURES
843c48fd
JG
246 help
247 Select this to enable optimizations for model z890/z990 (2084 and
248 2086 series). The kernel will be slightly faster but will not work
249 on older machines.
250
251config MARCH_Z9_109
252 bool "IBM System z9"
5a79859a 253 select HAVE_MARCH_Z9_109_FEATURES
843c48fd
JG
254 help
255 Select this to enable optimizations for IBM System z9 (2094 and
256 2096 series). The kernel will be slightly faster but will not work
257 on older machines.
258
259config MARCH_Z10
260 bool "IBM System z10"
5a79859a 261 select HAVE_MARCH_Z10_FEATURES
843c48fd
JG
262 help
263 Select this to enable optimizations for IBM System z10 (2097 and
264 2098 series). The kernel will be slightly faster but will not work
265 on older machines.
266
267config MARCH_Z196
268 bool "IBM zEnterprise 114 and 196"
5a79859a 269 select HAVE_MARCH_Z196_FEATURES
843c48fd
JG
270 help
271 Select this to enable optimizations for IBM zEnterprise 114 and 196
272 (2818 and 2817 series). The kernel will be slightly faster but will
273 not work on older machines.
1da177e4 274
991c1505 275config MARCH_ZEC12
59471227 276 bool "IBM zBC12 and zEC12"
5a79859a 277 select HAVE_MARCH_ZEC12_FEATURES
991c1505 278 help
59471227
HC
279 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
280 2827 series). The kernel will be slightly faster but will not work on
281 older machines.
991c1505 282
f8b2dcbd 283config MARCH_Z13
bb3aa614 284 bool "IBM z13s and z13"
5a79859a 285 select HAVE_MARCH_Z13_FEATURES
f8b2dcbd 286 help
bb3aa614
HC
287 Select this to enable optimizations for IBM z13s and z13 (2965 and
288 2964 series). The kernel will be slightly faster but will not work on
289 older machines.
f8b2dcbd 290
6997c323
MS
291config MARCH_Z14
292 bool "IBM z14"
293 select HAVE_MARCH_Z14_FEATURES
294 help
295 Select this to enable optimizations for IBM z14 (3906 series).
296 The kernel will be slightly faster but will not work on older
297 machines.
298
843c48fd 299endchoice
1da177e4 300
1db9e051
HC
301config MARCH_Z900_TUNE
302 def_bool TUNE_Z900 || MARCH_Z900 && TUNE_DEFAULT
303
304config MARCH_Z990_TUNE
305 def_bool TUNE_Z990 || MARCH_Z990 && TUNE_DEFAULT
306
307config MARCH_Z9_109_TUNE
308 def_bool TUNE_Z9_109 || MARCH_Z9_109 && TUNE_DEFAULT
309
310config MARCH_Z10_TUNE
311 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
312
313config MARCH_Z196_TUNE
314 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
315
316config MARCH_ZEC12_TUNE
317 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
318
f8b2dcbd
MS
319config MARCH_Z13_TUNE
320 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
321
6997c323
MS
322config MARCH_Z14_TUNE
323 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
324
1db9e051
HC
325choice
326 prompt "Tune code generation"
327 default TUNE_DEFAULT
328 help
329 Cause the compiler to tune (-mtune) the generated code for a machine.
330 This will make the code run faster on the selected machine but
331 somewhat slower on other machines.
332 This option only changes how the compiler emits instructions, not the
333 selection of instructions itself, so the resulting kernel will run on
334 all other machines.
335
336config TUNE_DEFAULT
337 bool "Default"
338 help
339 Tune the generated code for the target processor for which the kernel
340 will be compiled.
341
1db9e051
HC
342config TUNE_Z900
343 bool "IBM zSeries model z800 and z900"
344
345config TUNE_Z990
346 bool "IBM zSeries model z890 and z990"
347
348config TUNE_Z9_109
349 bool "IBM System z9"
350
351config TUNE_Z10
352 bool "IBM System z10"
353
354config TUNE_Z196
355 bool "IBM zEnterprise 114 and 196"
356
357config TUNE_ZEC12
358 bool "IBM zBC12 and zEC12"
359
f8b2dcbd
MS
360config TUNE_Z13
361 bool "IBM z13"
362
6997c323
MS
363config TUNE_Z14
364 bool "IBM z14"
365
1db9e051
HC
366endchoice
367
347a8dc3 368config 64BIT
6f9a3c33 369 def_bool y
d9f7a745 370
843c48fd
JG
371config COMPAT
372 def_bool y
373 prompt "Kernel support for 31 bit emulation"
843c48fd
JG
374 select COMPAT_BINFMT_ELF if BINFMT_ELF
375 select ARCH_WANT_OLD_COMPAT_IPC
7eddd99c 376 select COMPAT_OLD_SIGACTION
2813893f 377 depends on MULTIUSER
843c48fd
JG
378 help
379 Select this option if you want to enable your system kernel to
380 handle system-calls from ELF binaries for 31 bit ESA. This option
381 (and some other stuff like libraries and such) is needed for
382 executing 31 bit applications. It is safe to say "Y".
383
384config SYSVIPC_COMPAT
385 def_bool y if COMPAT && SYSVIPC
386
1da177e4 387config SMP
6f9a3c33
MS
388 def_bool y
389 prompt "Symmetric multi-processing support"
1da177e4
LT
390 ---help---
391 This enables support for systems with more than one CPU. If you have
392 a system with only one CPU, like most personal computers, say N. If
393 you have a system with more than one CPU, say Y.
394
4a474157 395 If you say N here, the kernel will run on uni- and multiprocessor
1da177e4
LT
396 machines, but will use only one CPU of a multiprocessor machine. If
397 you say Y here, the kernel will run on many, but not all,
4a474157 398 uniprocessor machines. On a uniprocessor machine, the kernel
1da177e4
LT
399 will run faster if you say N here.
400
03502faa
AB
401 See also the SMP-HOWTO available at
402 <http://www.tldp.org/docs.html#howto>.
1da177e4
LT
403
404 Even if you don't know what to do here, say Y.
405
406config NR_CPUS
5c75a0da
HC
407 int "Maximum number of CPUs (2-512)"
408 range 2 512
1da177e4 409 depends on SMP
5a79859a 410 default "64"
1da177e4
LT
411 help
412 This allows you to specify the maximum number of CPUs which this
5c75a0da 413 kernel will support. The maximum supported value is 512 and the
1da177e4
LT
414 minimum value which makes sense is 2.
415
416 This is purely to save memory - each supported CPU adds
417 approximately sixteen kilobytes to the kernel image.
418
419config HOTPLUG_CPU
6f9a3c33
MS
420 def_bool y
421 prompt "Support for hot-pluggable CPUs"
1da177e4 422 depends on SMP
1da177e4
LT
423 help
424 Say Y here to be able to turn CPUs off and on. CPUs
425 can be controlled through /sys/devices/system/cpu/cpu#.
426 Say N if you want to disable CPU hotplug.
427
3a368f74
PH
428# Some NUMA nodes have memory ranges that span
429# other nodes. Even though a pfn is valid and
430# between a node's start and end pfns, it may not
431# reside on that node. See memmap_init_zone()
432# for details. <- They meant memory holes!
433config NODES_SPAN_OTHER_NODES
434 def_bool NUMA
435
436config NUMA
437 bool "NUMA support"
c095a949 438 depends on SMP && SCHED_TOPOLOGY
3a368f74
PH
439 default n
440 help
441 Enable NUMA support
442
443 This option adds NUMA support to the kernel.
444
445 An operation mode can be selected by appending
446 numa=<method> to the kernel command line.
447
448 The default behaviour is identical to appending numa=plain to
449 the command line. This will create just one node with all
450 available memory and all CPUs in it.
451
452config NODES_SHIFT
453 int "Maximum NUMA nodes (as a power of 2)"
454 range 1 10
455 depends on NUMA
456 default "4"
457 help
458 Specify the maximum number of NUMA nodes available on the target
459 system. Increases memory reserved to accommodate various tables.
460
c29a7baf
MH
461menu "Select NUMA modes"
462 depends on NUMA
463
464config NUMA_EMU
465 bool "NUMA emulation"
466 default y
467 help
468 Numa emulation mode will split the available system memory into
469 equal chunks which then are distributed over the configured number
470 of nodes in a round-robin manner.
471
472 The number of fake nodes is limited by the number of available memory
473 chunks (i.e. memory size / fake size) and the number of supported
474 nodes in the kernel.
475
476 The CPUs are assigned to the nodes in a way that partially respects
477 the original machine topology (if supported by the machine).
478 Fair distribution of the CPUs is not guaranteed.
479
480config EMU_SIZE
481 hex "NUMA emulation memory chunk size"
482 default 0x10000000
483 range 0x400000 0x100000000
484 depends on NUMA_EMU
485 help
486 Select the default size by which the memory is chopped and then
487 assigned to emulated NUMA nodes.
488
489 This can be overridden by specifying
490
491 emu_size=<n>
492
493 on the kernel command line where also suffixes K, M, G, and T are
494 supported.
495
496endmenu
9236b4dd
HC
497
498config SCHED_SMT
499 def_bool n
c29a7baf 500
8d11e021 501config SCHED_MC
83a24e32 502 def_bool n
8d11e021 503
4cb14bc8 504config SCHED_BOOK
10ad34bc
MS
505 def_bool n
506
adac0f1e
HC
507config SCHED_DRAWER
508 def_bool n
509
10ad34bc 510config SCHED_TOPOLOGY
6f9a3c33 511 def_bool y
10ad34bc 512 prompt "Topology scheduler support"
83a24e32 513 depends on SMP
10ad34bc 514 select SCHED_SMT
83a24e32 515 select SCHED_MC
10ad34bc 516 select SCHED_BOOK
adac0f1e 517 select SCHED_DRAWER
4cb14bc8 518 help
10ad34bc
MS
519 Topology scheduler support improves the CPU scheduler's decision
520 making when dealing with machines that have multi-threading,
521 multiple cores or multiple books.
4cb14bc8 522
843c48fd
JG
523source kernel/Kconfig.preempt
524
843c48fd 525source kernel/Kconfig.hz
1da177e4 526
4c637cd8
HF
527config ARCH_RANDOM
528 def_bool y
529 prompt "s390 architectural random number generation API"
530 help
531 Enable the s390 architectural random number generation API
532 to provide random data for all consumers within the Linux
533 kernel.
534
535 When enabled the arch_random_* functions declared in linux/random.h
536 are implemented. The implementation is based on the s390 CPACF
537 instruction subfunction TRNG which provides a real true random
538 number generator.
539
540 If unsure, say Y.
541
d768bd89
MS
542config KERNEL_NOBP
543 def_bool n
544 prompt "Enable modified branch prediction for the kernel by default"
545 help
546 If this option is selected the kernel will switch to a modified
547 branch prediction mode if the firmware interface is available.
548 The modified branch prediction mode improves the behaviour in
549 regard to speculative execution.
550
551 With the option enabled the kernel parameter "nobp=0" or "nospec"
552 can be used to run the kernel in the normal branch prediction mode.
553
554 With the option disabled the modified branch prediction mode is
555 enabled with the "nobp=1" kernel parameter.
556
557 If unsure, say N.
558
f19fbd5e
MS
559config EXPOLINE
560 def_bool n
561 prompt "Avoid speculative indirect branches in the kernel"
562 help
563 Compile the kernel with the expoline compiler options to guard
564 against kernel-to-user data leaks by avoiding speculative indirect
565 branches.
566 Requires a compiler with -mindirect-branch=thunk support for full
567 protection. The kernel may run slower.
568
569 If unsure, say N.
570
571choice
572 prompt "Expoline default"
573 depends on EXPOLINE
574 default EXPOLINE_FULL
575
576config EXPOLINE_OFF
577 bool "spectre_v2=off"
578
6e179d64 579config EXPOLINE_AUTO
f19fbd5e
MS
580 bool "spectre_v2=auto"
581
582config EXPOLINE_FULL
583 bool "spectre_v2=on"
584
585endchoice
586
843c48fd 587endmenu
1da177e4 588
843c48fd 589menu "Memory setup"
1d057720 590
843c48fd 591config ARCH_SPARSEMEM_ENABLE
6f9a3c33 592 def_bool y
843c48fd
JG
593 select SPARSEMEM_VMEMMAP_ENABLE
594 select SPARSEMEM_VMEMMAP
e65e1fc2 595
843c48fd
JG
596config ARCH_SPARSEMEM_DEFAULT
597 def_bool y
1da177e4 598
843c48fd
JG
599config ARCH_SELECT_MEMORY_MODEL
600 def_bool y
1da177e4 601
843c48fd
JG
602config ARCH_ENABLE_MEMORY_HOTPLUG
603 def_bool y if SPARSEMEM
0efa4703 604
843c48fd
JG
605config ARCH_ENABLE_MEMORY_HOTREMOVE
606 def_bool y
e37f50e1 607
ec66ad66
MS
608config ARCH_ENABLE_SPLIT_PMD_PTLOCK
609 def_bool y
ec66ad66 610
843c48fd
JG
611config FORCE_MAX_ZONEORDER
612 int
613 default "9"
f861e405 614
843c48fd 615source "mm/Kconfig"
1da177e4 616
b8402b95
HC
617config MAX_PHYSMEM_BITS
618 int "Maximum size of supported physical memory in bits (42-53)"
619 range 42 53
620 default "46"
621 help
622 This option specifies the maximum supported size of physical memory
623 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
624 Increasing the number of bits also increases the kernel image size.
625 By default 46 bits (64TB) are supported.
626
1da177e4 627config PACK_STACK
6f9a3c33
MS
628 def_bool y
629 prompt "Pack kernel stack"
1da177e4
LT
630 help
631 This option enables the compiler option -mkernel-backchain if it
632 is available. If the option is available the compiler supports
633 the new stack layout which dramatically reduces the minimum stack
634 frame size. With an old compiler a non-leaf function needs a
635 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
636 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
637 and 24 byte on 64 bit.
638
639 Say Y if you are unsure.
640
1da177e4 641config CHECK_STACK
6f9a3c33
MS
642 def_bool y
643 prompt "Detect kernel stack overflow"
1da177e4
LT
644 help
645 This option enables the compiler option -mstack-guard and
646 -mstack-size if they are available. If the compiler supports them
647 it will emit additional code to each function prolog to trigger
648 an illegal operation if the kernel stack is about to overflow.
649
650 Say N if you are unsure.
651
652config STACK_GUARD
653 int "Size of the guard area (128-1024)"
654 range 128 1024
655 depends on CHECK_STACK
656 default "256"
657 help
658 This allows you to specify the size of the guard area at the lower
659 end of the kernel stack. If the kernel stack points into the guard
660 area on function entry an illegal operation is triggered. The size
661 needs to be a power of 2. Please keep in mind that the size of an
662 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
663 The minimum size for the stack guard should be 256 for 31 bit and
664 512 for 64 bit.
665
2c190da4 666config WARN_DYNAMIC_STACK
6f9a3c33 667 def_bool n
2c190da4 668 prompt "Emit compiler warnings for function with dynamic stack usage"
1da177e4 669 help
2c190da4
JG
670 This option enables the compiler option -mwarn-dynamicstack. If the
671 compiler supports this options generates warnings for functions
672 that dynamically allocate stack space using alloca.
1da177e4
LT
673
674 Say N if you are unsure.
675
843c48fd 676endmenu
3f22ab27 677
843c48fd 678menu "I/O subsystem"
1da177e4 679
1da177e4 680config QDIO
6f9a3c33
MS
681 def_tristate y
682 prompt "QDIO support"
1da177e4 683 ---help---
8129ee16 684 This driver provides the Queued Direct I/O base support for
efca13bc 685 IBM System z.
1da177e4
LT
686
687 To compile this driver as a module, choose M here: the
688 module will be called qdio.
689
690 If unsure, say Y.
691
c8717a3d
JG
692menuconfig PCI
693 bool "PCI support"
c8717a3d 694 select PCI_MSI
8128f23c 695 select IOMMU_SUPPORT
c8717a3d
JG
696 help
697 Enable PCI support.
698
699if PCI
700
701config PCI_NR_FUNCTIONS
702 int "Maximum number of PCI functions (1-4096)"
703 range 1 4096
b18601b0 704 default "128"
c8717a3d
JG
705 help
706 This allows you to specify the maximum number of PCI functions which
707 this kernel will support.
708
709source "drivers/pci/Kconfig"
c8717a3d
JG
710
711endif # PCI
712
713config PCI_DOMAINS
714 def_bool PCI
715
716config HAS_IOMEM
717 def_bool PCI
718
719config IOMMU_HELPER
720 def_bool PCI
721
c8717a3d
JG
722config NEED_SG_DMA_LENGTH
723 def_bool PCI
724
91630032
JG
725config NEED_DMA_MAP_STATE
726 def_bool PCI
727
9d92a7e1 728config CHSC_SCH
d9c11b1e 729 def_tristate m
6f9a3c33 730 prompt "Support for CHSC subchannels"
9d92a7e1
CH
731 help
732 This driver allows usage of CHSC subchannels. A CHSC subchannel
733 is usually present on LPAR only.
734 The driver creates a device /dev/chsc, which may be used to
735 obtain I/O configuration information about the machine and
736 to issue asynchronous chsc commands (DANGEROUS).
737 You will usually only want to use this interface on a special
738 LPAR designated for system management.
739
740 To compile this driver as a module, choose M here: the
741 module will be called chsc_sch.
742
743 If unsure, say N.
744
1d1c8f78
SO
745config SCM_BUS
746 def_bool y
1d1c8f78
SO
747 prompt "SCM bus driver"
748 help
749 Bus driver for Storage Class Memory.
750
eadb86ab
SO
751config EADM_SCH
752 def_tristate m
753 prompt "Support for EADM subchannels"
754 depends on SCM_BUS
755 help
756 This driver allows usage of EADM subchannels. EADM subchannels act
757 as a communication vehicle for SCM increments.
758
759 To compile this driver as a module, choose M here: the
760 module will be called eadm_sch.
761
63f1934d
DJS
762config VFIO_CCW
763 def_tristate n
764 prompt "Support for VFIO-CCW subchannels"
84cd8fc4 765 depends on S390_CCW_IOMMU && VFIO_MDEV
63f1934d
DJS
766 help
767 This driver allows usage of I/O subchannels via VFIO-CCW.
768
769 To compile this driver as a module, choose M here: the
770 module will be called vfio_ccw.
771
843c48fd
JG
772endmenu
773
774menu "Dump support"
775
776config CRASH_DUMP
777 bool "kernel crash dumps"
5a79859a 778 depends on SMP
843c48fd
JG
779 select KEXEC
780 help
781 Generate crash dump after being started by kexec.
782 Crash dump kernels are loaded in the main kernel with kexec-tools
783 into a specially reserved region and then later executed after
784 a crash by kdump/kexec.
843c48fd 785 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
bf28a597
MH
786 This option also enables s390 zfcpdump.
787 See also <file:Documentation/s390/zfcpdump.txt>
843c48fd
JG
788
789endmenu
790
791menu "Executable file formats / Emulations"
1da177e4 792
1da177e4
LT
793source "fs/Kconfig.binfmt"
794
843c48fd
JG
795config SECCOMP
796 def_bool y
797 prompt "Enable seccomp to safely compute untrusted bytecode"
798 depends on PROC_FS
799 help
800 This kernel feature is useful for number crunching applications
801 that may need to compute untrusted bytecode during their
802 execution. By using pipes or other transports made available to
803 the process as file descriptors supporting the read/write
804 syscalls, it's possible to isolate those applications in
805 their own address space using seccomp. Once seccomp is
806 enabled via /proc/<pid>/seccomp, it cannot be disabled
807 and the task is only allowed to execute a few safe syscalls
808 defined by each seccomp mode.
809
810 If unsure, say Y.
811
812endmenu
813
814menu "Power Management"
815
816config ARCH_HIBERNATION_POSSIBLE
5a79859a 817 def_bool y
843c48fd
JG
818
819source "kernel/power/Kconfig"
820
821endmenu
822
823source "net/Kconfig"
824
825config PCMCIA
826 def_bool n
827
828config CCW
829 def_bool y
830
831source "drivers/Kconfig"
832
833source "fs/Kconfig"
834
835source "arch/s390/Kconfig.debug"
836
837source "security/Kconfig"
838
839source "crypto/Kconfig"
840
841source "lib/Kconfig"
842
843menu "Virtualization"
684de39b 844
1da177e4 845config PFAULT
6f9a3c33
MS
846 def_bool y
847 prompt "Pseudo page fault support"
1da177e4
LT
848 help
849 Select this option, if you want to use PFAULT pseudo page fault
850 handling under VM. If running native or in LPAR, this option
851 has no effect. If your VM does not support PFAULT, PAGEEX
852 pseudo page fault handling will be used.
853 Note that VM 4.2 supports PFAULT but has a bug in its
854 implementation that causes some problems.
855 Everybody who wants to run Linux under VM != VM4.2 should select
856 this option.
857
1da177e4 858config CMM
6f9a3c33
MS
859 def_tristate n
860 prompt "Cooperative memory management"
1da177e4
LT
861 help
862 Select this option, if you want to enable the kernel interface
863 to reduce the memory size of the system. This is accomplished
864 by allocating pages of memory and put them "on hold". This only
865 makes sense for a system running under VM where the unused pages
866 will be reused by VM for other guest systems. The interface
867 allows an external monitor to balance memory of many systems.
868 Everybody who wants to run Linux under VM should select this
869 option.
870
1da177e4 871config CMM_IUCV
6f9a3c33
MS
872 def_bool y
873 prompt "IUCV special message interface to cooperative memory management"
1da177e4
LT
874 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
875 help
876 Select this option to enable the special message interface to
877 the cooperative memory management.
878
1da177e4 879config APPLDATA_BASE
6f9a3c33
MS
880 def_bool n
881 prompt "Linux - VM Monitor Stream, base infrastructure"
c185b783 882 depends on PROC_FS
1da177e4
LT
883 help
884 This provides a kernel interface for creating and updating z/VM APPLDATA
885 monitor records. The monitor records are updated at certain time
886 intervals, once the timer is started.
887 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
888 i.e. enables or disables monitoring on the Linux side.
889 A custom interval value (in seconds) can be written to
890 /proc/appldata/interval.
891
892 Defaults are 60 seconds interval and timer off.
893 The /proc entries can also be read from, showing the current settings.
894
895config APPLDATA_MEM
6f9a3c33
MS
896 def_tristate m
897 prompt "Monitor memory management statistics"
62fb2ba3 898 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
1da177e4
LT
899 help
900 This provides memory management related data to the Linux - VM Monitor
901 Stream, like paging/swapping rate, memory utilisation, etc.
902 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
903 APPLDATA monitor record, i.e. enables or disables monitoring this record
904 on the z/VM side.
905
906 Default is disabled.
907 The /proc entry can also be read from, showing the current settings.
908
909 This can also be compiled as a module, which will be called
910 appldata_mem.o.
911
912config APPLDATA_OS
6f9a3c33
MS
913 def_tristate m
914 prompt "Monitor OS statistics"
1da177e4
LT
915 depends on APPLDATA_BASE
916 help
917 This provides OS related data to the Linux - VM Monitor Stream, like
918 CPU utilisation, etc.
919 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
920 APPLDATA monitor record, i.e. enables or disables monitoring this record
921 on the z/VM side.
922
923 Default is disabled.
924 This can also be compiled as a module, which will be called
925 appldata_os.o.
926
927config APPLDATA_NET_SUM
6f9a3c33
MS
928 def_tristate m
929 prompt "Monitor overall network statistics"
70193af9 930 depends on APPLDATA_BASE && NET
1da177e4
LT
931 help
932 This provides network related data to the Linux - VM Monitor Stream,
933 currently there is only a total sum of network I/O statistics, no
934 per-interface data.
935 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
936 APPLDATA monitor record, i.e. enables or disables monitoring this record
937 on the z/VM side.
938
939 Default is disabled.
940 This can also be compiled as a module, which will be called
941 appldata_net_sum.o.
942
24bbb1fa 943config S390_HYPFS_FS
6f9a3c33
MS
944 def_bool y
945 prompt "s390 hypervisor file system support"
24bbb1fa 946 select SYS_HYPERVISOR
24bbb1fa
MH
947 help
948 This is a virtual file system intended to provide accounting
949 information in an s390 hypervisor environment.
950
843c48fd 951source "arch/s390/kvm/Kconfig"
411ed322 952
fa587743 953config S390_GUEST
6f9a3c33 954 def_bool y
510cf5a6 955 prompt "s390 support for virtio devices"
79b6f7fb 956 select TTY
80629b0b 957 select VIRTUALIZATION
fa587743 958 select VIRTIO
faeba830 959 select VIRTIO_CONSOLE
fa587743 960 help
bdd1fc27
CH
961 Enabling this option adds support for virtio based paravirtual device
962 drivers on s390.
1da177e4 963
20766c08 964 Select this option if you want to run the kernel as a guest under
bdd1fc27 965 the KVM hypervisor.
155af2f9
HJP
966
967endmenu