Merge branch 'vfs_timespec64' of https://github.com/deepa-hub/vfs into vfs-timespec64
[linux-2.6-block.git] / arch / s390 / Kconfig
CommitLineData
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 AUDIT_ARCH
51 def_bool y
52
ce816fa8 53config NO_IOPORT_MAP
c8717a3d
JG
54 def_bool y
55
56config PCI_QUIRKS
57 def_bool n
58
2a0a5b22 59config ARCH_SUPPORTS_UPROBES
5a79859a 60 def_bool y
2a0a5b22 61
347a8dc3 62config S390
61d48c2c 63 def_bool y
23fefe11 64 select ARCH_BINFMT_ELF_STATE
21266be9 65 select ARCH_HAS_DEVMEM_IS_ALLOWED
2b68f6ca 66 select ARCH_HAS_ELF_RANDOMIZE
79962038 67 select ARCH_HAS_FORTIFY_SOURCE
957e3fac 68 select ARCH_HAS_GCOV_PROFILE_ALL
e1073d1e 69 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
907fa061 70 select ARCH_HAS_KCOV
d2852a22 71 select ARCH_HAS_SET_MEMORY
47523c98 72 select ARCH_HAS_SG_CHAIN
ad21fc4f
LA
73 select ARCH_HAS_STRICT_KERNEL_RWX
74 select ARCH_HAS_STRICT_MODULE_RWX
c42d8c7d 75 select ARCH_HAS_UBSAN_SANITIZE_ALL
0e0d04a8 76 select ARCH_HAVE_NMI_SAFE_CMPXCHG
6beb0009
TG
77 select ARCH_INLINE_READ_LOCK
78 select ARCH_INLINE_READ_LOCK_BH
79 select ARCH_INLINE_READ_LOCK_IRQ
80 select ARCH_INLINE_READ_LOCK_IRQSAVE
0e0d04a8 81 select ARCH_INLINE_READ_TRYLOCK
6beb0009
TG
82 select ARCH_INLINE_READ_UNLOCK
83 select ARCH_INLINE_READ_UNLOCK_BH
84 select ARCH_INLINE_READ_UNLOCK_IRQ
85 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
0e0d04a8
HC
86 select ARCH_INLINE_SPIN_LOCK
87 select ARCH_INLINE_SPIN_LOCK_BH
88 select ARCH_INLINE_SPIN_LOCK_IRQ
89 select ARCH_INLINE_SPIN_LOCK_IRQSAVE
90 select ARCH_INLINE_SPIN_TRYLOCK
91 select ARCH_INLINE_SPIN_TRYLOCK_BH
92 select ARCH_INLINE_SPIN_UNLOCK
93 select ARCH_INLINE_SPIN_UNLOCK_BH
94 select ARCH_INLINE_SPIN_UNLOCK_IRQ
95 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
6beb0009
TG
96 select ARCH_INLINE_WRITE_LOCK
97 select ARCH_INLINE_WRITE_LOCK_BH
98 select ARCH_INLINE_WRITE_LOCK_IRQ
99 select ARCH_INLINE_WRITE_LOCK_IRQSAVE
0e0d04a8 100 select ARCH_INLINE_WRITE_TRYLOCK
6beb0009
TG
101 select ARCH_INLINE_WRITE_UNLOCK
102 select ARCH_INLINE_WRITE_UNLOCK_BH
103 select ARCH_INLINE_WRITE_UNLOCK_IRQ
104 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
0e0d04a8 105 select ARCH_SAVE_PAGE_KEYS if HIBERNATION
36e7fdaa 106 select ARCH_SUPPORTS_ATOMIC_RMW
a763bc8b 107 select ARCH_SUPPORTS_NUMA_BALANCING
295d8fa9 108 select ARCH_USE_BUILTIN_BSWAP
efc1d23b 109 select ARCH_USE_CMPXCHG_LOCKREF
3f6813b9 110 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
c42d8c7d 111 select ARCH_WANTS_UBSAN_NO_NULL
c1d7e01d 112 select ARCH_WANT_IPC_PARSE_VERSION
0e0d04a8
HC
113 select BUILDTIME_EXTABLE_SORT
114 select CLONE_BACKWARDS2
5d6a0163 115 select DYNAMIC_FTRACE if FUNCTION_TRACER
0e0d04a8 116 select GENERIC_CLOCKEVENTS
8f00b3e2 117 select GENERIC_CPU_AUTOPROBE
0e0d04a8 118 select GENERIC_CPU_DEVICES if !SMP
d424986f 119 select GENERIC_CPU_VULNERABILITIES
746479cd 120 select GENERIC_FIND_FIRST_BIT
e80e7813 121 select GENERIC_SMP_IDLE_THREAD
79c74ecb 122 select GENERIC_TIME_VSYSCALL
0e0d04a8 123 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
7a017721 124 select HAVE_ARCH_AUDITSYSCALL
5a79859a 125 select HAVE_ARCH_JUMP_LABEL
fff7fb0b 126 select CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES
c63cb468 127 select HAVE_ARCH_SECCOMP_FILTER
5614dd92 128 select HAVE_ARCH_SOFT_DIRTY
0e0d04a8 129 select HAVE_ARCH_TRACEHOOK
5a79859a 130 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
6077776b 131 select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
0e0d04a8
HC
132 select HAVE_CMPXCHG_DOUBLE
133 select HAVE_CMPXCHG_LOCAL
f50c0e63 134 select HAVE_COPY_THREAD_TLS
0e0d04a8 135 select HAVE_DEBUG_KMEMLEAK
e82becfc 136 select HAVE_DMA_API_DEBUG
e1231b0e 137 select HAVE_DMA_CONTIGUOUS
002e6745 138 select DMA_DIRECT_OPS
5a79859a
HC
139 select HAVE_DYNAMIC_FTRACE
140 select HAVE_DYNAMIC_FTRACE_WITH_REGS
9078a549 141 select HAVE_EFFICIENT_UNALIGNED_ACCESS
0e0d04a8 142 select HAVE_FTRACE_MCOUNT_RECORD
5a79859a
HC
143 select HAVE_FUNCTION_GRAPH_TRACER
144 select HAVE_FUNCTION_TRACER
03b8c7b6 145 select HAVE_FUTEX_CMPXCHG if FUTEX
dfd4c493 146 select HAVE_GCC_PLUGINS
0e0d04a8
HC
147 select HAVE_KERNEL_BZIP2
148 select HAVE_KERNEL_GZIP
8e2872ce 149 select HAVE_KERNEL_LZ4
0e0d04a8
HC
150 select HAVE_KERNEL_LZMA
151 select HAVE_KERNEL_LZO
152 select HAVE_KERNEL_XZ
153 select HAVE_KPROBES
154 select HAVE_KRETPROBES
5a79859a 155 select HAVE_KVM
21042d43 156 select HAVE_LIVEPATCH
c33eff60
HC
157 select HAVE_PERF_REGS
158 select HAVE_PERF_USER_STACK_DUMP
0e0d04a8
HC
159 select HAVE_MEMBLOCK
160 select HAVE_MEMBLOCK_NODE_MAP
50be6345 161 select HAVE_MEMBLOCK_PHYS_MAP
786d35d4 162 select HAVE_MOD_ARCH_SPECIFIC
0e0d04a8
HC
163 select HAVE_OPROFILE
164 select HAVE_PERF_EVENTS
165 select HAVE_REGS_AND_STACK_ACCESS_API
166 select HAVE_SYSCALL_TRACEPOINTS
0e0d04a8 167 select HAVE_VIRT_CPU_ACCOUNTING
786d35d4 168 select MODULES_USE_ELF_RELA
50be6345 169 select NO_BOOTMEM
7eddd99c 170 select OLD_SIGACTION
93bead43 171 select OLD_SIGSUSPEND3
bb98f396 172 select SPARSE_IRQ
0e0d04a8 173 select SYSCTL_EXCEPTION_TRACE
d5c352cd 174 select THREAD_INFO_IN_TASK
0563416b 175 select TTY
0e0d04a8 176 select VIRT_CPU_ACCOUNTING
40565b5a 177 select ARCH_HAS_SCALED_CPUTIME
93bead43 178 select VIRT_TO_BUS
42a0bb3f 179 select HAVE_NMI
3a368f74 180
1da177e4 181
fca3e357 182config SCHED_OMIT_FRAME_POINTER
6f9a3c33 183 def_bool y
fca3e357 184
c81956c9
KS
185config PGTABLE_LEVELS
186 int
1aea9b3f 187 default 5
c81956c9 188
1da177e4
LT
189source "init/Kconfig"
190
dc52ddc0
MH
191source "kernel/Kconfig.freezer"
192
21042d43
JS
193source "kernel/livepatch/Kconfig"
194
843c48fd
JG
195menu "Processor type and features"
196
197config HAVE_MARCH_Z900_FEATURES
198 def_bool n
199
200config HAVE_MARCH_Z990_FEATURES
201 def_bool n
202 select HAVE_MARCH_Z900_FEATURES
203
204config HAVE_MARCH_Z9_109_FEATURES
205 def_bool n
206 select HAVE_MARCH_Z990_FEATURES
207
208config HAVE_MARCH_Z10_FEATURES
209 def_bool n
210 select HAVE_MARCH_Z9_109_FEATURES
211
212config HAVE_MARCH_Z196_FEATURES
213 def_bool n
214 select HAVE_MARCH_Z10_FEATURES
215
991c1505
HC
216config HAVE_MARCH_ZEC12_FEATURES
217 def_bool n
218 select HAVE_MARCH_Z196_FEATURES
219
f8b2dcbd
MS
220config HAVE_MARCH_Z13_FEATURES
221 def_bool n
222 select HAVE_MARCH_ZEC12_FEATURES
223
6997c323
MS
224config HAVE_MARCH_Z14_FEATURES
225 def_bool n
226 select HAVE_MARCH_Z13_FEATURES
227
843c48fd
JG
228choice
229 prompt "Processor type"
7072276e 230 default MARCH_Z196
1da177e4 231
843c48fd
JG
232config MARCH_Z900
233 bool "IBM zSeries model z800 and z900"
5a79859a 234 select HAVE_MARCH_Z900_FEATURES
843c48fd
JG
235 help
236 Select this to enable optimizations for model z800/z900 (2064 and
237 2066 series). This will enable some optimizations that are not
238 available on older ESA/390 (31 Bit) only CPUs.
239
240config MARCH_Z990
241 bool "IBM zSeries model z890 and z990"
5a79859a 242 select HAVE_MARCH_Z990_FEATURES
843c48fd
JG
243 help
244 Select this to enable optimizations for model z890/z990 (2084 and
245 2086 series). The kernel will be slightly faster but will not work
246 on older machines.
247
248config MARCH_Z9_109
249 bool "IBM System z9"
5a79859a 250 select HAVE_MARCH_Z9_109_FEATURES
843c48fd
JG
251 help
252 Select this to enable optimizations for IBM System z9 (2094 and
253 2096 series). The kernel will be slightly faster but will not work
254 on older machines.
255
256config MARCH_Z10
257 bool "IBM System z10"
5a79859a 258 select HAVE_MARCH_Z10_FEATURES
843c48fd
JG
259 help
260 Select this to enable optimizations for IBM System z10 (2097 and
261 2098 series). The kernel will be slightly faster but will not work
262 on older machines.
263
264config MARCH_Z196
265 bool "IBM zEnterprise 114 and 196"
5a79859a 266 select HAVE_MARCH_Z196_FEATURES
843c48fd
JG
267 help
268 Select this to enable optimizations for IBM zEnterprise 114 and 196
269 (2818 and 2817 series). The kernel will be slightly faster but will
270 not work on older machines.
1da177e4 271
991c1505 272config MARCH_ZEC12
59471227 273 bool "IBM zBC12 and zEC12"
5a79859a 274 select HAVE_MARCH_ZEC12_FEATURES
991c1505 275 help
59471227
HC
276 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
277 2827 series). The kernel will be slightly faster but will not work on
278 older machines.
991c1505 279
f8b2dcbd 280config MARCH_Z13
bb3aa614 281 bool "IBM z13s and z13"
5a79859a 282 select HAVE_MARCH_Z13_FEATURES
f8b2dcbd 283 help
bb3aa614
HC
284 Select this to enable optimizations for IBM z13s and z13 (2965 and
285 2964 series). The kernel will be slightly faster but will not work on
286 older machines.
f8b2dcbd 287
6997c323 288config MARCH_Z14
451239eb 289 bool "IBM z14 ZR1 and z14"
6997c323
MS
290 select HAVE_MARCH_Z14_FEATURES
291 help
451239eb
HC
292 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
293 and 3906 series). The kernel will be slightly faster but will not
294 work on older machines.
6997c323 295
843c48fd 296endchoice
1da177e4 297
1db9e051
HC
298config MARCH_Z900_TUNE
299 def_bool TUNE_Z900 || MARCH_Z900 && TUNE_DEFAULT
300
301config MARCH_Z990_TUNE
302 def_bool TUNE_Z990 || MARCH_Z990 && TUNE_DEFAULT
303
304config MARCH_Z9_109_TUNE
305 def_bool TUNE_Z9_109 || MARCH_Z9_109 && TUNE_DEFAULT
306
307config MARCH_Z10_TUNE
308 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
309
310config MARCH_Z196_TUNE
311 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
312
313config MARCH_ZEC12_TUNE
314 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
315
f8b2dcbd
MS
316config MARCH_Z13_TUNE
317 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
318
6997c323
MS
319config MARCH_Z14_TUNE
320 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
321
1db9e051
HC
322choice
323 prompt "Tune code generation"
324 default TUNE_DEFAULT
325 help
326 Cause the compiler to tune (-mtune) the generated code for a machine.
327 This will make the code run faster on the selected machine but
328 somewhat slower on other machines.
329 This option only changes how the compiler emits instructions, not the
330 selection of instructions itself, so the resulting kernel will run on
331 all other machines.
332
333config TUNE_DEFAULT
334 bool "Default"
335 help
336 Tune the generated code for the target processor for which the kernel
337 will be compiled.
338
1db9e051
HC
339config TUNE_Z900
340 bool "IBM zSeries model z800 and z900"
341
342config TUNE_Z990
343 bool "IBM zSeries model z890 and z990"
344
345config TUNE_Z9_109
346 bool "IBM System z9"
347
348config TUNE_Z10
349 bool "IBM System z10"
350
351config TUNE_Z196
352 bool "IBM zEnterprise 114 and 196"
353
354config TUNE_ZEC12
355 bool "IBM zBC12 and zEC12"
356
f8b2dcbd
MS
357config TUNE_Z13
358 bool "IBM z13"
359
6997c323
MS
360config TUNE_Z14
361 bool "IBM z14"
362
1db9e051
HC
363endchoice
364
347a8dc3 365config 64BIT
6f9a3c33 366 def_bool y
d9f7a745 367
843c48fd
JG
368config COMPAT
369 def_bool y
370 prompt "Kernel support for 31 bit emulation"
843c48fd
JG
371 select COMPAT_BINFMT_ELF if BINFMT_ELF
372 select ARCH_WANT_OLD_COMPAT_IPC
7eddd99c 373 select COMPAT_OLD_SIGACTION
2813893f 374 depends on MULTIUSER
843c48fd
JG
375 help
376 Select this option if you want to enable your system kernel to
377 handle system-calls from ELF binaries for 31 bit ESA. This option
378 (and some other stuff like libraries and such) is needed for
379 executing 31 bit applications. It is safe to say "Y".
380
381config SYSVIPC_COMPAT
382 def_bool y if COMPAT && SYSVIPC
383
1da177e4 384config SMP
6f9a3c33
MS
385 def_bool y
386 prompt "Symmetric multi-processing support"
1da177e4
LT
387 ---help---
388 This enables support for systems with more than one CPU. If you have
389 a system with only one CPU, like most personal computers, say N. If
390 you have a system with more than one CPU, say Y.
391
4a474157 392 If you say N here, the kernel will run on uni- and multiprocessor
1da177e4
LT
393 machines, but will use only one CPU of a multiprocessor machine. If
394 you say Y here, the kernel will run on many, but not all,
4a474157 395 uniprocessor machines. On a uniprocessor machine, the kernel
1da177e4
LT
396 will run faster if you say N here.
397
03502faa
AB
398 See also the SMP-HOWTO available at
399 <http://www.tldp.org/docs.html#howto>.
1da177e4
LT
400
401 Even if you don't know what to do here, say Y.
402
403config NR_CPUS
5c75a0da
HC
404 int "Maximum number of CPUs (2-512)"
405 range 2 512
1da177e4 406 depends on SMP
5a79859a 407 default "64"
1da177e4
LT
408 help
409 This allows you to specify the maximum number of CPUs which this
5c75a0da 410 kernel will support. The maximum supported value is 512 and the
1da177e4
LT
411 minimum value which makes sense is 2.
412
413 This is purely to save memory - each supported CPU adds
414 approximately sixteen kilobytes to the kernel image.
415
416config HOTPLUG_CPU
6f9a3c33
MS
417 def_bool y
418 prompt "Support for hot-pluggable CPUs"
1da177e4 419 depends on SMP
1da177e4
LT
420 help
421 Say Y here to be able to turn CPUs off and on. CPUs
422 can be controlled through /sys/devices/system/cpu/cpu#.
423 Say N if you want to disable CPU hotplug.
424
3a368f74
PH
425# Some NUMA nodes have memory ranges that span
426# other nodes. Even though a pfn is valid and
427# between a node's start and end pfns, it may not
428# reside on that node. See memmap_init_zone()
429# for details. <- They meant memory holes!
430config NODES_SPAN_OTHER_NODES
431 def_bool NUMA
432
433config NUMA
434 bool "NUMA support"
c095a949 435 depends on SMP && SCHED_TOPOLOGY
3a368f74
PH
436 default n
437 help
438 Enable NUMA support
439
440 This option adds NUMA support to the kernel.
441
442 An operation mode can be selected by appending
443 numa=<method> to the kernel command line.
444
445 The default behaviour is identical to appending numa=plain to
446 the command line. This will create just one node with all
447 available memory and all CPUs in it.
448
449config NODES_SHIFT
450 int "Maximum NUMA nodes (as a power of 2)"
451 range 1 10
452 depends on NUMA
453 default "4"
454 help
455 Specify the maximum number of NUMA nodes available on the target
456 system. Increases memory reserved to accommodate various tables.
457
c29a7baf
MH
458menu "Select NUMA modes"
459 depends on NUMA
460
461config NUMA_EMU
462 bool "NUMA emulation"
463 default y
464 help
465 Numa emulation mode will split the available system memory into
466 equal chunks which then are distributed over the configured number
467 of nodes in a round-robin manner.
468
469 The number of fake nodes is limited by the number of available memory
470 chunks (i.e. memory size / fake size) and the number of supported
471 nodes in the kernel.
472
473 The CPUs are assigned to the nodes in a way that partially respects
474 the original machine topology (if supported by the machine).
475 Fair distribution of the CPUs is not guaranteed.
476
477config EMU_SIZE
478 hex "NUMA emulation memory chunk size"
479 default 0x10000000
480 range 0x400000 0x100000000
481 depends on NUMA_EMU
482 help
483 Select the default size by which the memory is chopped and then
484 assigned to emulated NUMA nodes.
485
486 This can be overridden by specifying
487
488 emu_size=<n>
489
490 on the kernel command line where also suffixes K, M, G, and T are
491 supported.
492
493endmenu
9236b4dd
HC
494
495config SCHED_SMT
496 def_bool n
c29a7baf 497
8d11e021 498config SCHED_MC
83a24e32 499 def_bool n
8d11e021 500
4cb14bc8 501config SCHED_BOOK
10ad34bc
MS
502 def_bool n
503
adac0f1e
HC
504config SCHED_DRAWER
505 def_bool n
506
10ad34bc 507config SCHED_TOPOLOGY
6f9a3c33 508 def_bool y
10ad34bc 509 prompt "Topology scheduler support"
83a24e32 510 depends on SMP
10ad34bc 511 select SCHED_SMT
83a24e32 512 select SCHED_MC
10ad34bc 513 select SCHED_BOOK
adac0f1e 514 select SCHED_DRAWER
4cb14bc8 515 help
10ad34bc
MS
516 Topology scheduler support improves the CPU scheduler's decision
517 making when dealing with machines that have multi-threading,
518 multiple cores or multiple books.
4cb14bc8 519
843c48fd
JG
520source kernel/Kconfig.preempt
521
843c48fd 522source kernel/Kconfig.hz
1da177e4 523
bdea9f6f
PR
524config KEXEC
525 def_bool y
526 select KEXEC_CORE
527
528config KEXEC_FILE
529 bool "kexec file based system call"
530 select KEXEC_CORE
531 select BUILD_BIN2C
532 depends on CRYPTO
533 depends on CRYPTO_SHA256
534 depends on CRYPTO_SHA256_S390
535 help
536 Enable the kexec file based system call. In contrast to the normal
537 kexec system call this system call takes file descriptors for the
538 kernel and initramfs as arguments.
539
540config ARCH_HAS_KEXEC_PURGATORY
541 def_bool y
542 depends on KEXEC_FILE
543
4c637cd8
HF
544config ARCH_RANDOM
545 def_bool y
546 prompt "s390 architectural random number generation API"
547 help
548 Enable the s390 architectural random number generation API
549 to provide random data for all consumers within the Linux
550 kernel.
551
552 When enabled the arch_random_* functions declared in linux/random.h
553 are implemented. The implementation is based on the s390 CPACF
554 instruction subfunction TRNG which provides a real true random
555 number generator.
556
557 If unsure, say Y.
558
d768bd89
MS
559config KERNEL_NOBP
560 def_bool n
561 prompt "Enable modified branch prediction for the kernel by default"
562 help
563 If this option is selected the kernel will switch to a modified
564 branch prediction mode if the firmware interface is available.
565 The modified branch prediction mode improves the behaviour in
566 regard to speculative execution.
567
568 With the option enabled the kernel parameter "nobp=0" or "nospec"
569 can be used to run the kernel in the normal branch prediction mode.
570
571 With the option disabled the modified branch prediction mode is
572 enabled with the "nobp=1" kernel parameter.
573
574 If unsure, say N.
575
f19fbd5e
MS
576config EXPOLINE
577 def_bool n
578 prompt "Avoid speculative indirect branches in the kernel"
579 help
580 Compile the kernel with the expoline compiler options to guard
581 against kernel-to-user data leaks by avoiding speculative indirect
582 branches.
583 Requires a compiler with -mindirect-branch=thunk support for full
584 protection. The kernel may run slower.
585
586 If unsure, say N.
587
588choice
589 prompt "Expoline default"
590 depends on EXPOLINE
591 default EXPOLINE_FULL
592
593config EXPOLINE_OFF
594 bool "spectre_v2=off"
595
6e179d64 596config EXPOLINE_AUTO
f19fbd5e
MS
597 bool "spectre_v2=auto"
598
599config EXPOLINE_FULL
600 bool "spectre_v2=on"
601
602endchoice
603
843c48fd 604endmenu
1da177e4 605
843c48fd 606menu "Memory setup"
1d057720 607
843c48fd 608config ARCH_SPARSEMEM_ENABLE
6f9a3c33 609 def_bool y
843c48fd
JG
610 select SPARSEMEM_VMEMMAP_ENABLE
611 select SPARSEMEM_VMEMMAP
e65e1fc2 612
843c48fd
JG
613config ARCH_SPARSEMEM_DEFAULT
614 def_bool y
1da177e4 615
843c48fd
JG
616config ARCH_SELECT_MEMORY_MODEL
617 def_bool y
1da177e4 618
843c48fd
JG
619config ARCH_ENABLE_MEMORY_HOTPLUG
620 def_bool y if SPARSEMEM
0efa4703 621
843c48fd
JG
622config ARCH_ENABLE_MEMORY_HOTREMOVE
623 def_bool y
e37f50e1 624
ec66ad66
MS
625config ARCH_ENABLE_SPLIT_PMD_PTLOCK
626 def_bool y
ec66ad66 627
843c48fd
JG
628config FORCE_MAX_ZONEORDER
629 int
630 default "9"
f861e405 631
843c48fd 632source "mm/Kconfig"
1da177e4 633
b8402b95
HC
634config MAX_PHYSMEM_BITS
635 int "Maximum size of supported physical memory in bits (42-53)"
636 range 42 53
637 default "46"
638 help
639 This option specifies the maximum supported size of physical memory
640 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
641 Increasing the number of bits also increases the kernel image size.
642 By default 46 bits (64TB) are supported.
643
1da177e4 644config PACK_STACK
6f9a3c33
MS
645 def_bool y
646 prompt "Pack kernel stack"
1da177e4
LT
647 help
648 This option enables the compiler option -mkernel-backchain if it
649 is available. If the option is available the compiler supports
650 the new stack layout which dramatically reduces the minimum stack
651 frame size. With an old compiler a non-leaf function needs a
652 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
653 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
654 and 24 byte on 64 bit.
655
656 Say Y if you are unsure.
657
1da177e4 658config CHECK_STACK
6f9a3c33
MS
659 def_bool y
660 prompt "Detect kernel stack overflow"
1da177e4
LT
661 help
662 This option enables the compiler option -mstack-guard and
663 -mstack-size if they are available. If the compiler supports them
664 it will emit additional code to each function prolog to trigger
665 an illegal operation if the kernel stack is about to overflow.
666
667 Say N if you are unsure.
668
669config STACK_GUARD
670 int "Size of the guard area (128-1024)"
671 range 128 1024
672 depends on CHECK_STACK
673 default "256"
674 help
675 This allows you to specify the size of the guard area at the lower
676 end of the kernel stack. If the kernel stack points into the guard
677 area on function entry an illegal operation is triggered. The size
678 needs to be a power of 2. Please keep in mind that the size of an
679 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
680 The minimum size for the stack guard should be 256 for 31 bit and
681 512 for 64 bit.
682
2c190da4 683config WARN_DYNAMIC_STACK
6f9a3c33 684 def_bool n
2c190da4 685 prompt "Emit compiler warnings for function with dynamic stack usage"
1da177e4 686 help
2c190da4
JG
687 This option enables the compiler option -mwarn-dynamicstack. If the
688 compiler supports this options generates warnings for functions
689 that dynamically allocate stack space using alloca.
1da177e4
LT
690
691 Say N if you are unsure.
692
843c48fd 693endmenu
3f22ab27 694
843c48fd 695menu "I/O subsystem"
1da177e4 696
1da177e4 697config QDIO
6f9a3c33
MS
698 def_tristate y
699 prompt "QDIO support"
1da177e4 700 ---help---
8129ee16 701 This driver provides the Queued Direct I/O base support for
efca13bc 702 IBM System z.
1da177e4
LT
703
704 To compile this driver as a module, choose M here: the
705 module will be called qdio.
706
707 If unsure, say Y.
708
c8717a3d
JG
709menuconfig PCI
710 bool "PCI support"
c8717a3d 711 select PCI_MSI
8128f23c 712 select IOMMU_SUPPORT
c8717a3d
JG
713 help
714 Enable PCI support.
715
716if PCI
717
718config PCI_NR_FUNCTIONS
719 int "Maximum number of PCI functions (1-4096)"
720 range 1 4096
b18601b0 721 default "128"
c8717a3d
JG
722 help
723 This allows you to specify the maximum number of PCI functions which
724 this kernel will support.
725
726source "drivers/pci/Kconfig"
c8717a3d
JG
727
728endif # PCI
729
730config PCI_DOMAINS
731 def_bool PCI
732
733config HAS_IOMEM
734 def_bool PCI
735
736config IOMMU_HELPER
737 def_bool PCI
738
c8717a3d
JG
739config NEED_SG_DMA_LENGTH
740 def_bool PCI
741
91630032
JG
742config NEED_DMA_MAP_STATE
743 def_bool PCI
744
9d92a7e1 745config CHSC_SCH
d9c11b1e 746 def_tristate m
6f9a3c33 747 prompt "Support for CHSC subchannels"
9d92a7e1
CH
748 help
749 This driver allows usage of CHSC subchannels. A CHSC subchannel
750 is usually present on LPAR only.
751 The driver creates a device /dev/chsc, which may be used to
752 obtain I/O configuration information about the machine and
753 to issue asynchronous chsc commands (DANGEROUS).
754 You will usually only want to use this interface on a special
755 LPAR designated for system management.
756
757 To compile this driver as a module, choose M here: the
758 module will be called chsc_sch.
759
760 If unsure, say N.
761
1d1c8f78
SO
762config SCM_BUS
763 def_bool y
1d1c8f78
SO
764 prompt "SCM bus driver"
765 help
766 Bus driver for Storage Class Memory.
767
eadb86ab
SO
768config EADM_SCH
769 def_tristate m
770 prompt "Support for EADM subchannels"
771 depends on SCM_BUS
772 help
773 This driver allows usage of EADM subchannels. EADM subchannels act
774 as a communication vehicle for SCM increments.
775
776 To compile this driver as a module, choose M here: the
777 module will be called eadm_sch.
778
63f1934d
DJS
779config VFIO_CCW
780 def_tristate n
781 prompt "Support for VFIO-CCW subchannels"
84cd8fc4 782 depends on S390_CCW_IOMMU && VFIO_MDEV
63f1934d
DJS
783 help
784 This driver allows usage of I/O subchannels via VFIO-CCW.
785
786 To compile this driver as a module, choose M here: the
787 module will be called vfio_ccw.
788
843c48fd
JG
789endmenu
790
791menu "Dump support"
792
793config CRASH_DUMP
794 bool "kernel crash dumps"
5a79859a 795 depends on SMP
843c48fd
JG
796 select KEXEC
797 help
798 Generate crash dump after being started by kexec.
799 Crash dump kernels are loaded in the main kernel with kexec-tools
800 into a specially reserved region and then later executed after
801 a crash by kdump/kexec.
843c48fd 802 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
bf28a597
MH
803 This option also enables s390 zfcpdump.
804 See also <file:Documentation/s390/zfcpdump.txt>
843c48fd
JG
805
806endmenu
807
808menu "Executable file formats / Emulations"
1da177e4 809
1da177e4
LT
810source "fs/Kconfig.binfmt"
811
843c48fd
JG
812config SECCOMP
813 def_bool y
814 prompt "Enable seccomp to safely compute untrusted bytecode"
815 depends on PROC_FS
816 help
817 This kernel feature is useful for number crunching applications
818 that may need to compute untrusted bytecode during their
819 execution. By using pipes or other transports made available to
820 the process as file descriptors supporting the read/write
821 syscalls, it's possible to isolate those applications in
822 their own address space using seccomp. Once seccomp is
823 enabled via /proc/<pid>/seccomp, it cannot be disabled
824 and the task is only allowed to execute a few safe syscalls
825 defined by each seccomp mode.
826
827 If unsure, say Y.
828
829endmenu
830
831menu "Power Management"
832
833config ARCH_HIBERNATION_POSSIBLE
5a79859a 834 def_bool y
843c48fd
JG
835
836source "kernel/power/Kconfig"
837
838endmenu
839
840source "net/Kconfig"
841
842config PCMCIA
843 def_bool n
844
845config CCW
846 def_bool y
847
848source "drivers/Kconfig"
849
850source "fs/Kconfig"
851
852source "arch/s390/Kconfig.debug"
853
854source "security/Kconfig"
855
856source "crypto/Kconfig"
857
858source "lib/Kconfig"
859
860menu "Virtualization"
684de39b 861
1da177e4 862config PFAULT
6f9a3c33
MS
863 def_bool y
864 prompt "Pseudo page fault support"
1da177e4
LT
865 help
866 Select this option, if you want to use PFAULT pseudo page fault
867 handling under VM. If running native or in LPAR, this option
868 has no effect. If your VM does not support PFAULT, PAGEEX
869 pseudo page fault handling will be used.
870 Note that VM 4.2 supports PFAULT but has a bug in its
871 implementation that causes some problems.
872 Everybody who wants to run Linux under VM != VM4.2 should select
873 this option.
874
1da177e4 875config CMM
6f9a3c33
MS
876 def_tristate n
877 prompt "Cooperative memory management"
1da177e4
LT
878 help
879 Select this option, if you want to enable the kernel interface
880 to reduce the memory size of the system. This is accomplished
881 by allocating pages of memory and put them "on hold". This only
882 makes sense for a system running under VM where the unused pages
883 will be reused by VM for other guest systems. The interface
884 allows an external monitor to balance memory of many systems.
885 Everybody who wants to run Linux under VM should select this
886 option.
887
1da177e4 888config CMM_IUCV
6f9a3c33
MS
889 def_bool y
890 prompt "IUCV special message interface to cooperative memory management"
1da177e4
LT
891 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
892 help
893 Select this option to enable the special message interface to
894 the cooperative memory management.
895
1da177e4 896config APPLDATA_BASE
6f9a3c33
MS
897 def_bool n
898 prompt "Linux - VM Monitor Stream, base infrastructure"
c185b783 899 depends on PROC_FS
1da177e4
LT
900 help
901 This provides a kernel interface for creating and updating z/VM APPLDATA
902 monitor records. The monitor records are updated at certain time
903 intervals, once the timer is started.
904 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
905 i.e. enables or disables monitoring on the Linux side.
906 A custom interval value (in seconds) can be written to
907 /proc/appldata/interval.
908
909 Defaults are 60 seconds interval and timer off.
910 The /proc entries can also be read from, showing the current settings.
911
912config APPLDATA_MEM
6f9a3c33
MS
913 def_tristate m
914 prompt "Monitor memory management statistics"
62fb2ba3 915 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
1da177e4
LT
916 help
917 This provides memory management related data to the Linux - VM Monitor
918 Stream, like paging/swapping rate, memory utilisation, etc.
919 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
920 APPLDATA monitor record, i.e. enables or disables monitoring this record
921 on the z/VM side.
922
923 Default is disabled.
924 The /proc entry can also be read from, showing the current settings.
925
926 This can also be compiled as a module, which will be called
927 appldata_mem.o.
928
929config APPLDATA_OS
6f9a3c33
MS
930 def_tristate m
931 prompt "Monitor OS statistics"
1da177e4
LT
932 depends on APPLDATA_BASE
933 help
934 This provides OS related data to the Linux - VM Monitor Stream, like
935 CPU utilisation, etc.
936 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
937 APPLDATA monitor record, i.e. enables or disables monitoring this record
938 on the z/VM side.
939
940 Default is disabled.
941 This can also be compiled as a module, which will be called
942 appldata_os.o.
943
944config APPLDATA_NET_SUM
6f9a3c33
MS
945 def_tristate m
946 prompt "Monitor overall network statistics"
70193af9 947 depends on APPLDATA_BASE && NET
1da177e4
LT
948 help
949 This provides network related data to the Linux - VM Monitor Stream,
950 currently there is only a total sum of network I/O statistics, no
951 per-interface data.
952 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
953 APPLDATA monitor record, i.e. enables or disables monitoring this record
954 on the z/VM side.
955
956 Default is disabled.
957 This can also be compiled as a module, which will be called
958 appldata_net_sum.o.
959
24bbb1fa 960config S390_HYPFS_FS
6f9a3c33
MS
961 def_bool y
962 prompt "s390 hypervisor file system support"
24bbb1fa 963 select SYS_HYPERVISOR
24bbb1fa
MH
964 help
965 This is a virtual file system intended to provide accounting
966 information in an s390 hypervisor environment.
967
843c48fd 968source "arch/s390/kvm/Kconfig"
411ed322 969
fa587743 970config S390_GUEST
6f9a3c33 971 def_bool y
510cf5a6 972 prompt "s390 support for virtio devices"
79b6f7fb 973 select TTY
80629b0b 974 select VIRTUALIZATION
fa587743 975 select VIRTIO
faeba830 976 select VIRTIO_CONSOLE
fa587743 977 help
bdd1fc27
CH
978 Enabling this option adds support for virtio based paravirtual device
979 drivers on s390.
1da177e4 980
20766c08 981 Select this option if you want to run the kernel as a guest under
bdd1fc27 982 the KVM hypervisor.
155af2f9
HJP
983
984endmenu