Merge tag 'gfs2-4.19.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2...
[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
b6b40c53 38config GENERIC_LOCKBREAK
6f9a3c33 39 def_bool y if SMP && PREEMPT
b6b40c53 40
402b0862 41config PGSTE
6f9a3c33 42 def_bool y if KVM
402b0862 43
6a11f75b
AM
44config ARCH_SUPPORTS_DEBUG_PAGEALLOC
45 def_bool y
46
843c48fd
JG
47config AUDIT_ARCH
48 def_bool y
49
ce816fa8 50config NO_IOPORT_MAP
c8717a3d
JG
51 def_bool y
52
53config PCI_QUIRKS
54 def_bool n
55
2a0a5b22 56config ARCH_SUPPORTS_UPROBES
5a79859a 57 def_bool y
2a0a5b22 58
347a8dc3 59config S390
61d48c2c 60 def_bool y
23fefe11 61 select ARCH_BINFMT_ELF_STATE
21266be9 62 select ARCH_HAS_DEVMEM_IS_ALLOWED
2b68f6ca 63 select ARCH_HAS_ELF_RANDOMIZE
79962038 64 select ARCH_HAS_FORTIFY_SOURCE
957e3fac 65 select ARCH_HAS_GCOV_PROFILE_ALL
e1073d1e 66 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
907fa061 67 select ARCH_HAS_KCOV
3010a5ea 68 select ARCH_HAS_PTE_SPECIAL
d2852a22 69 select ARCH_HAS_SET_MEMORY
47523c98 70 select ARCH_HAS_SG_CHAIN
ad21fc4f
LA
71 select ARCH_HAS_STRICT_KERNEL_RWX
72 select ARCH_HAS_STRICT_MODULE_RWX
c42d8c7d 73 select ARCH_HAS_UBSAN_SANITIZE_ALL
0e0d04a8 74 select ARCH_HAVE_NMI_SAFE_CMPXCHG
6beb0009
TG
75 select ARCH_INLINE_READ_LOCK
76 select ARCH_INLINE_READ_LOCK_BH
77 select ARCH_INLINE_READ_LOCK_IRQ
78 select ARCH_INLINE_READ_LOCK_IRQSAVE
0e0d04a8 79 select ARCH_INLINE_READ_TRYLOCK
6beb0009
TG
80 select ARCH_INLINE_READ_UNLOCK
81 select ARCH_INLINE_READ_UNLOCK_BH
82 select ARCH_INLINE_READ_UNLOCK_IRQ
83 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
0e0d04a8
HC
84 select ARCH_INLINE_SPIN_LOCK
85 select ARCH_INLINE_SPIN_LOCK_BH
86 select ARCH_INLINE_SPIN_LOCK_IRQ
87 select ARCH_INLINE_SPIN_LOCK_IRQSAVE
88 select ARCH_INLINE_SPIN_TRYLOCK
89 select ARCH_INLINE_SPIN_TRYLOCK_BH
90 select ARCH_INLINE_SPIN_UNLOCK
91 select ARCH_INLINE_SPIN_UNLOCK_BH
92 select ARCH_INLINE_SPIN_UNLOCK_IRQ
93 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
6beb0009
TG
94 select ARCH_INLINE_WRITE_LOCK
95 select ARCH_INLINE_WRITE_LOCK_BH
96 select ARCH_INLINE_WRITE_LOCK_IRQ
97 select ARCH_INLINE_WRITE_LOCK_IRQSAVE
0e0d04a8 98 select ARCH_INLINE_WRITE_TRYLOCK
6beb0009
TG
99 select ARCH_INLINE_WRITE_UNLOCK
100 select ARCH_INLINE_WRITE_UNLOCK_BH
101 select ARCH_INLINE_WRITE_UNLOCK_IRQ
102 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
0e0d04a8 103 select ARCH_SAVE_PAGE_KEYS if HIBERNATION
36e7fdaa 104 select ARCH_SUPPORTS_ATOMIC_RMW
a763bc8b 105 select ARCH_SUPPORTS_NUMA_BALANCING
295d8fa9 106 select ARCH_USE_BUILTIN_BSWAP
efc1d23b 107 select ARCH_USE_CMPXCHG_LOCKREF
3f6813b9 108 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
c1d7e01d 109 select ARCH_WANT_IPC_PARSE_VERSION
0e0d04a8
HC
110 select BUILDTIME_EXTABLE_SORT
111 select CLONE_BACKWARDS2
5d6a0163 112 select DYNAMIC_FTRACE if FUNCTION_TRACER
0e0d04a8 113 select GENERIC_CLOCKEVENTS
8f00b3e2 114 select GENERIC_CPU_AUTOPROBE
0e0d04a8 115 select GENERIC_CPU_DEVICES if !SMP
d424986f 116 select GENERIC_CPU_VULNERABILITIES
746479cd 117 select GENERIC_FIND_FIRST_BIT
e80e7813 118 select GENERIC_SMP_IDLE_THREAD
79c74ecb 119 select GENERIC_TIME_VSYSCALL
0e0d04a8 120 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
7a017721 121 select HAVE_ARCH_AUDITSYSCALL
5a79859a 122 select HAVE_ARCH_JUMP_LABEL
fff7fb0b 123 select CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES
c63cb468 124 select HAVE_ARCH_SECCOMP_FILTER
5614dd92 125 select HAVE_ARCH_SOFT_DIRTY
0e0d04a8 126 select HAVE_ARCH_TRACEHOOK
5a79859a 127 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
6077776b 128 select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
0e0d04a8
HC
129 select HAVE_CMPXCHG_DOUBLE
130 select HAVE_CMPXCHG_LOCAL
f50c0e63 131 select HAVE_COPY_THREAD_TLS
0e0d04a8 132 select HAVE_DEBUG_KMEMLEAK
e1231b0e 133 select HAVE_DMA_CONTIGUOUS
002e6745 134 select DMA_DIRECT_OPS
5a79859a
HC
135 select HAVE_DYNAMIC_FTRACE
136 select HAVE_DYNAMIC_FTRACE_WITH_REGS
9078a549 137 select HAVE_EFFICIENT_UNALIGNED_ACCESS
0e0d04a8 138 select HAVE_FTRACE_MCOUNT_RECORD
5a79859a
HC
139 select HAVE_FUNCTION_GRAPH_TRACER
140 select HAVE_FUNCTION_TRACER
03b8c7b6 141 select HAVE_FUTEX_CMPXCHG if FUTEX
2fba3573 142 select HAVE_GCC_PLUGINS if BROKEN
0e0d04a8
HC
143 select HAVE_KERNEL_BZIP2
144 select HAVE_KERNEL_GZIP
8e2872ce 145 select HAVE_KERNEL_LZ4
0e0d04a8
HC
146 select HAVE_KERNEL_LZMA
147 select HAVE_KERNEL_LZO
89b5202e 148 select HAVE_KERNEL_UNCOMPRESSED
0e0d04a8
HC
149 select HAVE_KERNEL_XZ
150 select HAVE_KPROBES
151 select HAVE_KRETPROBES
5a79859a 152 select HAVE_KVM
21042d43 153 select HAVE_LIVEPATCH
c33eff60
HC
154 select HAVE_PERF_REGS
155 select HAVE_PERF_USER_STACK_DUMP
0e0d04a8
HC
156 select HAVE_MEMBLOCK
157 select HAVE_MEMBLOCK_NODE_MAP
50be6345 158 select HAVE_MEMBLOCK_PHYS_MAP
786d35d4 159 select HAVE_MOD_ARCH_SPECIFIC
0e0d04a8
HC
160 select HAVE_OPROFILE
161 select HAVE_PERF_EVENTS
162 select HAVE_REGS_AND_STACK_ACCESS_API
9d6d99e3 163 select HAVE_RSEQ
0e0d04a8 164 select HAVE_SYSCALL_TRACEPOINTS
0e0d04a8 165 select HAVE_VIRT_CPU_ACCOUNTING
786d35d4 166 select MODULES_USE_ELF_RELA
50be6345 167 select NO_BOOTMEM
7eddd99c 168 select OLD_SIGACTION
93bead43 169 select OLD_SIGSUSPEND3
bb98f396 170 select SPARSE_IRQ
0e0d04a8 171 select SYSCTL_EXCEPTION_TRACE
d5c352cd 172 select THREAD_INFO_IN_TASK
0563416b 173 select TTY
0e0d04a8 174 select VIRT_CPU_ACCOUNTING
40565b5a 175 select ARCH_HAS_SCALED_CPUTIME
93bead43 176 select VIRT_TO_BUS
42a0bb3f 177 select HAVE_NMI
3a368f74 178
1da177e4 179
fca3e357 180config SCHED_OMIT_FRAME_POINTER
6f9a3c33 181 def_bool y
fca3e357 182
c81956c9
KS
183config PGTABLE_LEVELS
184 int
1aea9b3f 185 default 5
c81956c9 186
21042d43
JS
187source "kernel/livepatch/Kconfig"
188
843c48fd
JG
189menu "Processor type and features"
190
191config HAVE_MARCH_Z900_FEATURES
192 def_bool n
193
194config HAVE_MARCH_Z990_FEATURES
195 def_bool n
196 select HAVE_MARCH_Z900_FEATURES
197
198config HAVE_MARCH_Z9_109_FEATURES
199 def_bool n
200 select HAVE_MARCH_Z990_FEATURES
201
202config HAVE_MARCH_Z10_FEATURES
203 def_bool n
204 select HAVE_MARCH_Z9_109_FEATURES
205
206config HAVE_MARCH_Z196_FEATURES
207 def_bool n
208 select HAVE_MARCH_Z10_FEATURES
209
991c1505
HC
210config HAVE_MARCH_ZEC12_FEATURES
211 def_bool n
212 select HAVE_MARCH_Z196_FEATURES
213
f8b2dcbd
MS
214config HAVE_MARCH_Z13_FEATURES
215 def_bool n
216 select HAVE_MARCH_ZEC12_FEATURES
217
6997c323
MS
218config HAVE_MARCH_Z14_FEATURES
219 def_bool n
220 select HAVE_MARCH_Z13_FEATURES
221
843c48fd
JG
222choice
223 prompt "Processor type"
7072276e 224 default MARCH_Z196
1da177e4 225
843c48fd
JG
226config MARCH_Z900
227 bool "IBM zSeries model z800 and z900"
5a79859a 228 select HAVE_MARCH_Z900_FEATURES
843c48fd
JG
229 help
230 Select this to enable optimizations for model z800/z900 (2064 and
231 2066 series). This will enable some optimizations that are not
232 available on older ESA/390 (31 Bit) only CPUs.
233
234config MARCH_Z990
235 bool "IBM zSeries model z890 and z990"
5a79859a 236 select HAVE_MARCH_Z990_FEATURES
843c48fd
JG
237 help
238 Select this to enable optimizations for model z890/z990 (2084 and
239 2086 series). The kernel will be slightly faster but will not work
240 on older machines.
241
242config MARCH_Z9_109
243 bool "IBM System z9"
5a79859a 244 select HAVE_MARCH_Z9_109_FEATURES
843c48fd
JG
245 help
246 Select this to enable optimizations for IBM System z9 (2094 and
247 2096 series). The kernel will be slightly faster but will not work
248 on older machines.
249
250config MARCH_Z10
251 bool "IBM System z10"
5a79859a 252 select HAVE_MARCH_Z10_FEATURES
843c48fd
JG
253 help
254 Select this to enable optimizations for IBM System z10 (2097 and
255 2098 series). The kernel will be slightly faster but will not work
256 on older machines.
257
258config MARCH_Z196
259 bool "IBM zEnterprise 114 and 196"
5a79859a 260 select HAVE_MARCH_Z196_FEATURES
843c48fd
JG
261 help
262 Select this to enable optimizations for IBM zEnterprise 114 and 196
263 (2818 and 2817 series). The kernel will be slightly faster but will
264 not work on older machines.
1da177e4 265
991c1505 266config MARCH_ZEC12
59471227 267 bool "IBM zBC12 and zEC12"
5a79859a 268 select HAVE_MARCH_ZEC12_FEATURES
991c1505 269 help
59471227
HC
270 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
271 2827 series). The kernel will be slightly faster but will not work on
272 older machines.
991c1505 273
f8b2dcbd 274config MARCH_Z13
bb3aa614 275 bool "IBM z13s and z13"
5a79859a 276 select HAVE_MARCH_Z13_FEATURES
f8b2dcbd 277 help
bb3aa614
HC
278 Select this to enable optimizations for IBM z13s and z13 (2965 and
279 2964 series). The kernel will be slightly faster but will not work on
280 older machines.
f8b2dcbd 281
6997c323 282config MARCH_Z14
451239eb 283 bool "IBM z14 ZR1 and z14"
6997c323
MS
284 select HAVE_MARCH_Z14_FEATURES
285 help
451239eb
HC
286 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
287 and 3906 series). The kernel will be slightly faster but will not
288 work on older machines.
6997c323 289
843c48fd 290endchoice
1da177e4 291
1db9e051
HC
292config MARCH_Z900_TUNE
293 def_bool TUNE_Z900 || MARCH_Z900 && TUNE_DEFAULT
294
295config MARCH_Z990_TUNE
296 def_bool TUNE_Z990 || MARCH_Z990 && TUNE_DEFAULT
297
298config MARCH_Z9_109_TUNE
299 def_bool TUNE_Z9_109 || MARCH_Z9_109 && TUNE_DEFAULT
300
301config MARCH_Z10_TUNE
302 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
303
304config MARCH_Z196_TUNE
305 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
306
307config MARCH_ZEC12_TUNE
308 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
309
f8b2dcbd
MS
310config MARCH_Z13_TUNE
311 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
312
6997c323
MS
313config MARCH_Z14_TUNE
314 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
315
1db9e051
HC
316choice
317 prompt "Tune code generation"
318 default TUNE_DEFAULT
319 help
320 Cause the compiler to tune (-mtune) the generated code for a machine.
321 This will make the code run faster on the selected machine but
322 somewhat slower on other machines.
323 This option only changes how the compiler emits instructions, not the
324 selection of instructions itself, so the resulting kernel will run on
325 all other machines.
326
327config TUNE_DEFAULT
328 bool "Default"
329 help
330 Tune the generated code for the target processor for which the kernel
331 will be compiled.
332
1db9e051
HC
333config TUNE_Z900
334 bool "IBM zSeries model z800 and z900"
335
336config TUNE_Z990
337 bool "IBM zSeries model z890 and z990"
338
339config TUNE_Z9_109
340 bool "IBM System z9"
341
342config TUNE_Z10
343 bool "IBM System z10"
344
345config TUNE_Z196
346 bool "IBM zEnterprise 114 and 196"
347
348config TUNE_ZEC12
349 bool "IBM zBC12 and zEC12"
350
f8b2dcbd
MS
351config TUNE_Z13
352 bool "IBM z13"
353
6997c323
MS
354config TUNE_Z14
355 bool "IBM z14"
356
1db9e051
HC
357endchoice
358
347a8dc3 359config 64BIT
6f9a3c33 360 def_bool y
d9f7a745 361
843c48fd
JG
362config COMPAT
363 def_bool y
364 prompt "Kernel support for 31 bit emulation"
843c48fd
JG
365 select COMPAT_BINFMT_ELF if BINFMT_ELF
366 select ARCH_WANT_OLD_COMPAT_IPC
7eddd99c 367 select COMPAT_OLD_SIGACTION
2813893f 368 depends on MULTIUSER
843c48fd
JG
369 help
370 Select this option if you want to enable your system kernel to
371 handle system-calls from ELF binaries for 31 bit ESA. This option
372 (and some other stuff like libraries and such) is needed for
373 executing 31 bit applications. It is safe to say "Y".
374
375config SYSVIPC_COMPAT
376 def_bool y if COMPAT && SYSVIPC
377
1da177e4 378config SMP
6f9a3c33
MS
379 def_bool y
380 prompt "Symmetric multi-processing support"
1da177e4
LT
381 ---help---
382 This enables support for systems with more than one CPU. If you have
383 a system with only one CPU, like most personal computers, say N. If
384 you have a system with more than one CPU, say Y.
385
4a474157 386 If you say N here, the kernel will run on uni- and multiprocessor
1da177e4
LT
387 machines, but will use only one CPU of a multiprocessor machine. If
388 you say Y here, the kernel will run on many, but not all,
4a474157 389 uniprocessor machines. On a uniprocessor machine, the kernel
1da177e4
LT
390 will run faster if you say N here.
391
03502faa
AB
392 See also the SMP-HOWTO available at
393 <http://www.tldp.org/docs.html#howto>.
1da177e4
LT
394
395 Even if you don't know what to do here, say Y.
396
397config NR_CPUS
5c75a0da
HC
398 int "Maximum number of CPUs (2-512)"
399 range 2 512
1da177e4 400 depends on SMP
5a79859a 401 default "64"
1da177e4
LT
402 help
403 This allows you to specify the maximum number of CPUs which this
5c75a0da 404 kernel will support. The maximum supported value is 512 and the
1da177e4
LT
405 minimum value which makes sense is 2.
406
407 This is purely to save memory - each supported CPU adds
408 approximately sixteen kilobytes to the kernel image.
409
410config HOTPLUG_CPU
6f9a3c33
MS
411 def_bool y
412 prompt "Support for hot-pluggable CPUs"
1da177e4 413 depends on SMP
1da177e4
LT
414 help
415 Say Y here to be able to turn CPUs off and on. CPUs
416 can be controlled through /sys/devices/system/cpu/cpu#.
417 Say N if you want to disable CPU hotplug.
418
3a368f74
PH
419# Some NUMA nodes have memory ranges that span
420# other nodes. Even though a pfn is valid and
421# between a node's start and end pfns, it may not
422# reside on that node. See memmap_init_zone()
423# for details. <- They meant memory holes!
424config NODES_SPAN_OTHER_NODES
425 def_bool NUMA
426
427config NUMA
428 bool "NUMA support"
c095a949 429 depends on SMP && SCHED_TOPOLOGY
3a368f74
PH
430 default n
431 help
432 Enable NUMA support
433
434 This option adds NUMA support to the kernel.
435
436 An operation mode can be selected by appending
437 numa=<method> to the kernel command line.
438
439 The default behaviour is identical to appending numa=plain to
440 the command line. This will create just one node with all
441 available memory and all CPUs in it.
442
443config NODES_SHIFT
444 int "Maximum NUMA nodes (as a power of 2)"
445 range 1 10
446 depends on NUMA
447 default "4"
448 help
449 Specify the maximum number of NUMA nodes available on the target
450 system. Increases memory reserved to accommodate various tables.
451
c29a7baf
MH
452menu "Select NUMA modes"
453 depends on NUMA
454
455config NUMA_EMU
456 bool "NUMA emulation"
457 default y
458 help
459 Numa emulation mode will split the available system memory into
460 equal chunks which then are distributed over the configured number
461 of nodes in a round-robin manner.
462
463 The number of fake nodes is limited by the number of available memory
464 chunks (i.e. memory size / fake size) and the number of supported
465 nodes in the kernel.
466
467 The CPUs are assigned to the nodes in a way that partially respects
468 the original machine topology (if supported by the machine).
469 Fair distribution of the CPUs is not guaranteed.
470
471config EMU_SIZE
472 hex "NUMA emulation memory chunk size"
473 default 0x10000000
474 range 0x400000 0x100000000
475 depends on NUMA_EMU
476 help
477 Select the default size by which the memory is chopped and then
478 assigned to emulated NUMA nodes.
479
480 This can be overridden by specifying
481
482 emu_size=<n>
483
484 on the kernel command line where also suffixes K, M, G, and T are
485 supported.
486
487endmenu
9236b4dd
HC
488
489config SCHED_SMT
490 def_bool n
c29a7baf 491
8d11e021 492config SCHED_MC
83a24e32 493 def_bool n
8d11e021 494
4cb14bc8 495config SCHED_BOOK
10ad34bc
MS
496 def_bool n
497
adac0f1e
HC
498config SCHED_DRAWER
499 def_bool n
500
10ad34bc 501config SCHED_TOPOLOGY
6f9a3c33 502 def_bool y
10ad34bc 503 prompt "Topology scheduler support"
83a24e32 504 depends on SMP
10ad34bc 505 select SCHED_SMT
83a24e32 506 select SCHED_MC
10ad34bc 507 select SCHED_BOOK
adac0f1e 508 select SCHED_DRAWER
4cb14bc8 509 help
10ad34bc
MS
510 Topology scheduler support improves the CPU scheduler's decision
511 making when dealing with machines that have multi-threading,
512 multiple cores or multiple books.
4cb14bc8 513
843c48fd 514source kernel/Kconfig.hz
1da177e4 515
bdea9f6f
PR
516config KEXEC
517 def_bool y
518 select KEXEC_CORE
519
520config KEXEC_FILE
521 bool "kexec file based system call"
522 select KEXEC_CORE
523 select BUILD_BIN2C
524 depends on CRYPTO
525 depends on CRYPTO_SHA256
526 depends on CRYPTO_SHA256_S390
527 help
528 Enable the kexec file based system call. In contrast to the normal
529 kexec system call this system call takes file descriptors for the
530 kernel and initramfs as arguments.
531
532config ARCH_HAS_KEXEC_PURGATORY
533 def_bool y
534 depends on KEXEC_FILE
535
4c637cd8
HF
536config ARCH_RANDOM
537 def_bool y
538 prompt "s390 architectural random number generation API"
539 help
540 Enable the s390 architectural random number generation API
541 to provide random data for all consumers within the Linux
542 kernel.
543
544 When enabled the arch_random_* functions declared in linux/random.h
545 are implemented. The implementation is based on the s390 CPACF
546 instruction subfunction TRNG which provides a real true random
547 number generator.
548
549 If unsure, say Y.
550
d768bd89
MS
551config KERNEL_NOBP
552 def_bool n
553 prompt "Enable modified branch prediction for the kernel by default"
554 help
555 If this option is selected the kernel will switch to a modified
556 branch prediction mode if the firmware interface is available.
557 The modified branch prediction mode improves the behaviour in
558 regard to speculative execution.
559
560 With the option enabled the kernel parameter "nobp=0" or "nospec"
561 can be used to run the kernel in the normal branch prediction mode.
562
563 With the option disabled the modified branch prediction mode is
564 enabled with the "nobp=1" kernel parameter.
565
566 If unsure, say N.
567
f19fbd5e
MS
568config EXPOLINE
569 def_bool n
570 prompt "Avoid speculative indirect branches in the kernel"
571 help
572 Compile the kernel with the expoline compiler options to guard
573 against kernel-to-user data leaks by avoiding speculative indirect
574 branches.
575 Requires a compiler with -mindirect-branch=thunk support for full
576 protection. The kernel may run slower.
577
578 If unsure, say N.
579
580choice
581 prompt "Expoline default"
582 depends on EXPOLINE
583 default EXPOLINE_FULL
584
585config EXPOLINE_OFF
586 bool "spectre_v2=off"
587
6e179d64 588config EXPOLINE_AUTO
f19fbd5e
MS
589 bool "spectre_v2=auto"
590
591config EXPOLINE_FULL
592 bool "spectre_v2=on"
593
594endchoice
595
843c48fd 596endmenu
1da177e4 597
843c48fd 598menu "Memory setup"
1d057720 599
843c48fd 600config ARCH_SPARSEMEM_ENABLE
6f9a3c33 601 def_bool y
843c48fd
JG
602 select SPARSEMEM_VMEMMAP_ENABLE
603 select SPARSEMEM_VMEMMAP
e65e1fc2 604
843c48fd
JG
605config ARCH_SPARSEMEM_DEFAULT
606 def_bool y
1da177e4 607
843c48fd
JG
608config ARCH_SELECT_MEMORY_MODEL
609 def_bool y
1da177e4 610
843c48fd
JG
611config ARCH_ENABLE_MEMORY_HOTPLUG
612 def_bool y if SPARSEMEM
0efa4703 613
843c48fd
JG
614config ARCH_ENABLE_MEMORY_HOTREMOVE
615 def_bool y
e37f50e1 616
ec66ad66
MS
617config ARCH_ENABLE_SPLIT_PMD_PTLOCK
618 def_bool y
ec66ad66 619
843c48fd
JG
620config FORCE_MAX_ZONEORDER
621 int
622 default "9"
f861e405 623
b8402b95
HC
624config MAX_PHYSMEM_BITS
625 int "Maximum size of supported physical memory in bits (42-53)"
626 range 42 53
627 default "46"
628 help
629 This option specifies the maximum supported size of physical memory
630 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
631 Increasing the number of bits also increases the kernel image size.
632 By default 46 bits (64TB) are supported.
633
1da177e4 634config PACK_STACK
6f9a3c33
MS
635 def_bool y
636 prompt "Pack kernel stack"
1da177e4
LT
637 help
638 This option enables the compiler option -mkernel-backchain if it
639 is available. If the option is available the compiler supports
640 the new stack layout which dramatically reduces the minimum stack
641 frame size. With an old compiler a non-leaf function needs a
642 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
643 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
644 and 24 byte on 64 bit.
645
646 Say Y if you are unsure.
647
1da177e4 648config CHECK_STACK
6f9a3c33
MS
649 def_bool y
650 prompt "Detect kernel stack overflow"
1da177e4
LT
651 help
652 This option enables the compiler option -mstack-guard and
653 -mstack-size if they are available. If the compiler supports them
654 it will emit additional code to each function prolog to trigger
655 an illegal operation if the kernel stack is about to overflow.
656
657 Say N if you are unsure.
658
659config STACK_GUARD
660 int "Size of the guard area (128-1024)"
661 range 128 1024
662 depends on CHECK_STACK
663 default "256"
664 help
665 This allows you to specify the size of the guard area at the lower
666 end of the kernel stack. If the kernel stack points into the guard
667 area on function entry an illegal operation is triggered. The size
668 needs to be a power of 2. Please keep in mind that the size of an
669 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
670 The minimum size for the stack guard should be 256 for 31 bit and
671 512 for 64 bit.
672
2c190da4 673config WARN_DYNAMIC_STACK
6f9a3c33 674 def_bool n
2c190da4 675 prompt "Emit compiler warnings for function with dynamic stack usage"
1da177e4 676 help
2c190da4
JG
677 This option enables the compiler option -mwarn-dynamicstack. If the
678 compiler supports this options generates warnings for functions
679 that dynamically allocate stack space using alloca.
1da177e4
LT
680
681 Say N if you are unsure.
682
843c48fd 683endmenu
3f22ab27 684
843c48fd 685menu "I/O subsystem"
1da177e4 686
1da177e4 687config QDIO
6f9a3c33
MS
688 def_tristate y
689 prompt "QDIO support"
1da177e4 690 ---help---
8129ee16 691 This driver provides the Queued Direct I/O base support for
efca13bc 692 IBM System z.
1da177e4
LT
693
694 To compile this driver as a module, choose M here: the
695 module will be called qdio.
696
697 If unsure, say Y.
698
c8717a3d
JG
699menuconfig PCI
700 bool "PCI support"
c8717a3d 701 select PCI_MSI
a4ce5a48 702 select IOMMU_HELPER
8128f23c 703 select IOMMU_SUPPORT
f616ab59 704 select NEED_DMA_MAP_STATE
86596f0a 705 select NEED_SG_DMA_LENGTH
a4ce5a48 706
c8717a3d
JG
707 help
708 Enable PCI support.
709
710if PCI
711
712config PCI_NR_FUNCTIONS
713 int "Maximum number of PCI functions (1-4096)"
714 range 1 4096
b18601b0 715 default "128"
c8717a3d
JG
716 help
717 This allows you to specify the maximum number of PCI functions which
718 this kernel will support.
719
720source "drivers/pci/Kconfig"
c8717a3d
JG
721
722endif # PCI
723
724config PCI_DOMAINS
725 def_bool PCI
726
727config HAS_IOMEM
728 def_bool PCI
729
9d92a7e1 730config CHSC_SCH
d9c11b1e 731 def_tristate m
6f9a3c33 732 prompt "Support for CHSC subchannels"
9d92a7e1
CH
733 help
734 This driver allows usage of CHSC subchannels. A CHSC subchannel
735 is usually present on LPAR only.
736 The driver creates a device /dev/chsc, which may be used to
737 obtain I/O configuration information about the machine and
738 to issue asynchronous chsc commands (DANGEROUS).
739 You will usually only want to use this interface on a special
740 LPAR designated for system management.
741
742 To compile this driver as a module, choose M here: the
743 module will be called chsc_sch.
744
745 If unsure, say N.
746
1d1c8f78
SO
747config SCM_BUS
748 def_bool y
1d1c8f78
SO
749 prompt "SCM bus driver"
750 help
751 Bus driver for Storage Class Memory.
752
eadb86ab
SO
753config EADM_SCH
754 def_tristate m
755 prompt "Support for EADM subchannels"
756 depends on SCM_BUS
757 help
758 This driver allows usage of EADM subchannels. EADM subchannels act
759 as a communication vehicle for SCM increments.
760
761 To compile this driver as a module, choose M here: the
762 module will be called eadm_sch.
763
63f1934d
DJS
764config VFIO_CCW
765 def_tristate n
766 prompt "Support for VFIO-CCW subchannels"
84cd8fc4 767 depends on S390_CCW_IOMMU && VFIO_MDEV
63f1934d
DJS
768 help
769 This driver allows usage of I/O subchannels via VFIO-CCW.
770
771 To compile this driver as a module, choose M here: the
772 module will be called vfio_ccw.
773
843c48fd
JG
774endmenu
775
776menu "Dump support"
777
778config CRASH_DUMP
779 bool "kernel crash dumps"
5a79859a 780 depends on SMP
843c48fd
JG
781 select KEXEC
782 help
783 Generate crash dump after being started by kexec.
784 Crash dump kernels are loaded in the main kernel with kexec-tools
785 into a specially reserved region and then later executed after
786 a crash by kdump/kexec.
843c48fd 787 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
bf28a597
MH
788 This option also enables s390 zfcpdump.
789 See also <file:Documentation/s390/zfcpdump.txt>
843c48fd
JG
790
791endmenu
792
843c48fd
JG
793config SECCOMP
794 def_bool y
795 prompt "Enable seccomp to safely compute untrusted bytecode"
796 depends on PROC_FS
797 help
798 This kernel feature is useful for number crunching applications
799 that may need to compute untrusted bytecode during their
800 execution. By using pipes or other transports made available to
801 the process as file descriptors supporting the read/write
802 syscalls, it's possible to isolate those applications in
803 their own address space using seccomp. Once seccomp is
804 enabled via /proc/<pid>/seccomp, it cannot be disabled
805 and the task is only allowed to execute a few safe syscalls
806 defined by each seccomp mode.
807
808 If unsure, say Y.
809
843c48fd
JG
810menu "Power Management"
811
812config ARCH_HIBERNATION_POSSIBLE
5a79859a 813 def_bool y
843c48fd
JG
814
815source "kernel/power/Kconfig"
816
817endmenu
818
843c48fd
JG
819config PCMCIA
820 def_bool n
821
822config CCW
823 def_bool y
824
b6ef86e9
UB
825config HAVE_PNETID
826 tristate
827 default (SMC || CCWGROUP)
828
843c48fd 829menu "Virtualization"
684de39b 830
1da177e4 831config PFAULT
6f9a3c33
MS
832 def_bool y
833 prompt "Pseudo page fault support"
1da177e4
LT
834 help
835 Select this option, if you want to use PFAULT pseudo page fault
836 handling under VM. If running native or in LPAR, this option
837 has no effect. If your VM does not support PFAULT, PAGEEX
838 pseudo page fault handling will be used.
839 Note that VM 4.2 supports PFAULT but has a bug in its
840 implementation that causes some problems.
841 Everybody who wants to run Linux under VM != VM4.2 should select
842 this option.
843
1da177e4 844config CMM
6f9a3c33
MS
845 def_tristate n
846 prompt "Cooperative memory management"
1da177e4
LT
847 help
848 Select this option, if you want to enable the kernel interface
849 to reduce the memory size of the system. This is accomplished
850 by allocating pages of memory and put them "on hold". This only
851 makes sense for a system running under VM where the unused pages
852 will be reused by VM for other guest systems. The interface
853 allows an external monitor to balance memory of many systems.
854 Everybody who wants to run Linux under VM should select this
855 option.
856
1da177e4 857config CMM_IUCV
6f9a3c33
MS
858 def_bool y
859 prompt "IUCV special message interface to cooperative memory management"
1da177e4
LT
860 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
861 help
862 Select this option to enable the special message interface to
863 the cooperative memory management.
864
1da177e4 865config APPLDATA_BASE
6f9a3c33
MS
866 def_bool n
867 prompt "Linux - VM Monitor Stream, base infrastructure"
c185b783 868 depends on PROC_FS
1da177e4
LT
869 help
870 This provides a kernel interface for creating and updating z/VM APPLDATA
871 monitor records. The monitor records are updated at certain time
872 intervals, once the timer is started.
873 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
874 i.e. enables or disables monitoring on the Linux side.
875 A custom interval value (in seconds) can be written to
876 /proc/appldata/interval.
877
878 Defaults are 60 seconds interval and timer off.
879 The /proc entries can also be read from, showing the current settings.
880
881config APPLDATA_MEM
6f9a3c33
MS
882 def_tristate m
883 prompt "Monitor memory management statistics"
62fb2ba3 884 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
1da177e4
LT
885 help
886 This provides memory management related data to the Linux - VM Monitor
887 Stream, like paging/swapping rate, memory utilisation, etc.
888 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
889 APPLDATA monitor record, i.e. enables or disables monitoring this record
890 on the z/VM side.
891
892 Default is disabled.
893 The /proc entry can also be read from, showing the current settings.
894
895 This can also be compiled as a module, which will be called
896 appldata_mem.o.
897
898config APPLDATA_OS
6f9a3c33
MS
899 def_tristate m
900 prompt "Monitor OS statistics"
1da177e4
LT
901 depends on APPLDATA_BASE
902 help
903 This provides OS related data to the Linux - VM Monitor Stream, like
904 CPU utilisation, etc.
905 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
906 APPLDATA monitor record, i.e. enables or disables monitoring this record
907 on the z/VM side.
908
909 Default is disabled.
910 This can also be compiled as a module, which will be called
911 appldata_os.o.
912
913config APPLDATA_NET_SUM
6f9a3c33
MS
914 def_tristate m
915 prompt "Monitor overall network statistics"
70193af9 916 depends on APPLDATA_BASE && NET
1da177e4
LT
917 help
918 This provides network related data to the Linux - VM Monitor Stream,
919 currently there is only a total sum of network I/O statistics, no
920 per-interface data.
921 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
922 APPLDATA monitor record, i.e. enables or disables monitoring this record
923 on the z/VM side.
924
925 Default is disabled.
926 This can also be compiled as a module, which will be called
927 appldata_net_sum.o.
928
24bbb1fa 929config S390_HYPFS_FS
6f9a3c33
MS
930 def_bool y
931 prompt "s390 hypervisor file system support"
24bbb1fa 932 select SYS_HYPERVISOR
24bbb1fa
MH
933 help
934 This is a virtual file system intended to provide accounting
935 information in an s390 hypervisor environment.
936
843c48fd 937source "arch/s390/kvm/Kconfig"
411ed322 938
fa587743 939config S390_GUEST
6f9a3c33 940 def_bool y
510cf5a6 941 prompt "s390 support for virtio devices"
79b6f7fb 942 select TTY
80629b0b 943 select VIRTUALIZATION
fa587743 944 select VIRTIO
faeba830 945 select VIRTIO_CONSOLE
fa587743 946 help
bdd1fc27
CH
947 Enabling this option adds support for virtio based paravirtual device
948 drivers on s390.
1da177e4 949
20766c08 950 Select this option if you want to run the kernel as a guest under
bdd1fc27 951 the KVM hypervisor.
155af2f9
HJP
952
953endmenu