1# SPDX-License-Identifier: GPL-2.0 2config MMU 3 def_bool y 4 5config ZONE_DMA 6 def_bool y 7 8config CPU_BIG_ENDIAN 9 def_bool y 10 11config LOCKDEP_SUPPORT 12 def_bool y 13 14config STACKTRACE_SUPPORT 15 def_bool y 16 17config RWSEM_GENERIC_SPINLOCK 18 bool 19 20config RWSEM_XCHGADD_ALGORITHM 21 def_bool y 22 23config ARCH_HAS_ILOG2_U32 24 def_bool n 25 26config ARCH_HAS_ILOG2_U64 27 def_bool n 28 29config GENERIC_HWEIGHT 30 def_bool y 31 32config GENERIC_BUG 33 def_bool y if BUG 34 35config GENERIC_BUG_RELATIVE_POINTERS 36 def_bool y 37 38config GENERIC_LOCKBREAK 39 def_bool y if SMP && PREEMPT 40 41config PGSTE 42 def_bool y if KVM 43 44config ARCH_SUPPORTS_DEBUG_PAGEALLOC 45 def_bool y 46 47config AUDIT_ARCH 48 def_bool y 49 50config NO_IOPORT_MAP 51 def_bool y 52 53config PCI_QUIRKS 54 def_bool n 55 56config ARCH_SUPPORTS_UPROBES 57 def_bool y 58 59config KASAN_SHADOW_OFFSET 60 hex 61 depends on KASAN 62 default 0x18000000000000 if KASAN_S390_4_LEVEL_PAGING 63 default 0x30000000000 64 65config S390 66 def_bool y 67 select ARCH_BINFMT_ELF_STATE 68 select ARCH_HAS_DEVMEM_IS_ALLOWED 69 select ARCH_HAS_ELF_RANDOMIZE 70 select ARCH_HAS_FORTIFY_SOURCE 71 select ARCH_HAS_GCOV_PROFILE_ALL 72 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA 73 select ARCH_HAS_KCOV 74 select ARCH_HAS_PTE_SPECIAL 75 select ARCH_HAS_SET_MEMORY 76 select ARCH_HAS_STRICT_KERNEL_RWX 77 select ARCH_HAS_STRICT_MODULE_RWX 78 select ARCH_HAS_SYSCALL_WRAPPER 79 select ARCH_HAS_UBSAN_SANITIZE_ALL 80 select ARCH_HAVE_NMI_SAFE_CMPXCHG 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 85 select ARCH_INLINE_READ_TRYLOCK 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 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 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 104 select ARCH_INLINE_WRITE_TRYLOCK 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 109 select ARCH_SAVE_PAGE_KEYS if HIBERNATION 110 select ARCH_SUPPORTS_ATOMIC_RMW 111 select ARCH_SUPPORTS_NUMA_BALANCING 112 select ARCH_USE_BUILTIN_BSWAP 113 select ARCH_USE_CMPXCHG_LOCKREF 114 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 115 select ARCH_WANT_IPC_PARSE_VERSION 116 select BUILDTIME_EXTABLE_SORT 117 select CLONE_BACKWARDS2 118 select DYNAMIC_FTRACE if FUNCTION_TRACER 119 select GENERIC_CLOCKEVENTS 120 select GENERIC_CPU_AUTOPROBE 121 select GENERIC_CPU_DEVICES if !SMP 122 select GENERIC_CPU_VULNERABILITIES 123 select GENERIC_FIND_FIRST_BIT 124 select GENERIC_SMP_IDLE_THREAD 125 select GENERIC_TIME_VSYSCALL 126 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 127 select HAVE_ARCH_AUDITSYSCALL 128 select HAVE_ARCH_JUMP_LABEL 129 select HAVE_ARCH_JUMP_LABEL_RELATIVE 130 select HAVE_ARCH_KASAN 131 select CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES 132 select HAVE_ARCH_SECCOMP_FILTER 133 select HAVE_ARCH_SOFT_DIRTY 134 select HAVE_ARCH_TRACEHOOK 135 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 136 select HAVE_ARCH_VMAP_STACK 137 select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES 138 select HAVE_CMPXCHG_DOUBLE 139 select HAVE_CMPXCHG_LOCAL 140 select HAVE_COPY_THREAD_TLS 141 select HAVE_DEBUG_KMEMLEAK 142 select HAVE_DMA_CONTIGUOUS 143 select HAVE_DYNAMIC_FTRACE 144 select HAVE_DYNAMIC_FTRACE_WITH_REGS 145 select HAVE_EFFICIENT_UNALIGNED_ACCESS 146 select HAVE_FENTRY 147 select HAVE_FTRACE_MCOUNT_RECORD 148 select HAVE_FUNCTION_GRAPH_TRACER 149 select HAVE_FUNCTION_TRACER 150 select HAVE_FUTEX_CMPXCHG if FUTEX 151 select HAVE_GCC_PLUGINS 152 select HAVE_KERNEL_BZIP2 153 select HAVE_KERNEL_GZIP 154 select HAVE_KERNEL_LZ4 155 select HAVE_KERNEL_LZMA 156 select HAVE_KERNEL_LZO 157 select HAVE_KERNEL_UNCOMPRESSED 158 select HAVE_KERNEL_XZ 159 select HAVE_KPROBES 160 select HAVE_KRETPROBES 161 select HAVE_KVM 162 select HAVE_LIVEPATCH 163 select HAVE_PERF_REGS 164 select HAVE_PERF_USER_STACK_DUMP 165 select HAVE_MEMBLOCK_NODE_MAP 166 select HAVE_MEMBLOCK_PHYS_MAP 167 select HAVE_MOD_ARCH_SPECIFIC 168 select HAVE_NOP_MCOUNT 169 select HAVE_OPROFILE 170 select HAVE_PCI 171 select HAVE_PERF_EVENTS 172 select HAVE_REGS_AND_STACK_ACCESS_API 173 select HAVE_RSEQ 174 select HAVE_SYSCALL_TRACEPOINTS 175 select HAVE_VIRT_CPU_ACCOUNTING 176 select IOMMU_HELPER if PCI 177 select IOMMU_SUPPORT if PCI 178 select MODULES_USE_ELF_RELA 179 select NEED_DMA_MAP_STATE if PCI 180 select NEED_SG_DMA_LENGTH if PCI 181 select OLD_SIGACTION 182 select OLD_SIGSUSPEND3 183 select PCI_DOMAINS if PCI 184 select PCI_MSI if PCI 185 select SPARSE_IRQ 186 select SYSCTL_EXCEPTION_TRACE 187 select THREAD_INFO_IN_TASK 188 select TTY 189 select VIRT_CPU_ACCOUNTING 190 select ARCH_HAS_SCALED_CPUTIME 191 select VIRT_TO_BUS 192 select HAVE_NMI 193 194 195config SCHED_OMIT_FRAME_POINTER 196 def_bool y 197 198config PGTABLE_LEVELS 199 int 200 default 5 201 202source "kernel/livepatch/Kconfig" 203 204menu "Processor type and features" 205 206config HAVE_MARCH_Z900_FEATURES 207 def_bool n 208 209config HAVE_MARCH_Z990_FEATURES 210 def_bool n 211 select HAVE_MARCH_Z900_FEATURES 212 213config HAVE_MARCH_Z9_109_FEATURES 214 def_bool n 215 select HAVE_MARCH_Z990_FEATURES 216 217config HAVE_MARCH_Z10_FEATURES 218 def_bool n 219 select HAVE_MARCH_Z9_109_FEATURES 220 221config HAVE_MARCH_Z196_FEATURES 222 def_bool n 223 select HAVE_MARCH_Z10_FEATURES 224 225config HAVE_MARCH_ZEC12_FEATURES 226 def_bool n 227 select HAVE_MARCH_Z196_FEATURES 228 229config HAVE_MARCH_Z13_FEATURES 230 def_bool n 231 select HAVE_MARCH_ZEC12_FEATURES 232 233config HAVE_MARCH_Z14_FEATURES 234 def_bool n 235 select HAVE_MARCH_Z13_FEATURES 236 237choice 238 prompt "Processor type" 239 default MARCH_Z196 240 241config MARCH_Z900 242 bool "IBM zSeries model z800 and z900" 243 select HAVE_MARCH_Z900_FEATURES 244 help 245 Select this to enable optimizations for model z800/z900 (2064 and 246 2066 series). This will enable some optimizations that are not 247 available on older ESA/390 (31 Bit) only CPUs. 248 249config MARCH_Z990 250 bool "IBM zSeries model z890 and z990" 251 select HAVE_MARCH_Z990_FEATURES 252 help 253 Select this to enable optimizations for model z890/z990 (2084 and 254 2086 series). The kernel will be slightly faster but will not work 255 on older machines. 256 257config MARCH_Z9_109 258 bool "IBM System z9" 259 select HAVE_MARCH_Z9_109_FEATURES 260 help 261 Select this to enable optimizations for IBM System z9 (2094 and 262 2096 series). The kernel will be slightly faster but will not work 263 on older machines. 264 265config MARCH_Z10 266 bool "IBM System z10" 267 select HAVE_MARCH_Z10_FEATURES 268 help 269 Select this to enable optimizations for IBM System z10 (2097 and 270 2098 series). The kernel will be slightly faster but will not work 271 on older machines. 272 273config MARCH_Z196 274 bool "IBM zEnterprise 114 and 196" 275 select HAVE_MARCH_Z196_FEATURES 276 help 277 Select this to enable optimizations for IBM zEnterprise 114 and 196 278 (2818 and 2817 series). The kernel will be slightly faster but will 279 not work on older machines. 280 281config MARCH_ZEC12 282 bool "IBM zBC12 and zEC12" 283 select HAVE_MARCH_ZEC12_FEATURES 284 help 285 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and 286 2827 series). The kernel will be slightly faster but will not work on 287 older machines. 288 289config MARCH_Z13 290 bool "IBM z13s and z13" 291 select HAVE_MARCH_Z13_FEATURES 292 help 293 Select this to enable optimizations for IBM z13s and z13 (2965 and 294 2964 series). The kernel will be slightly faster but will not work on 295 older machines. 296 297config MARCH_Z14 298 bool "IBM z14 ZR1 and z14" 299 select HAVE_MARCH_Z14_FEATURES 300 help 301 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907 302 and 3906 series). The kernel will be slightly faster but will not 303 work on older machines. 304 305endchoice 306 307config MARCH_Z900_TUNE 308 def_bool TUNE_Z900 || MARCH_Z900 && TUNE_DEFAULT 309 310config MARCH_Z990_TUNE 311 def_bool TUNE_Z990 || MARCH_Z990 && TUNE_DEFAULT 312 313config MARCH_Z9_109_TUNE 314 def_bool TUNE_Z9_109 || MARCH_Z9_109 && TUNE_DEFAULT 315 316config MARCH_Z10_TUNE 317 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT 318 319config MARCH_Z196_TUNE 320 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT 321 322config MARCH_ZEC12_TUNE 323 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT 324 325config MARCH_Z13_TUNE 326 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT 327 328config MARCH_Z14_TUNE 329 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT 330 331choice 332 prompt "Tune code generation" 333 default TUNE_DEFAULT 334 help 335 Cause the compiler to tune (-mtune) the generated code for a machine. 336 This will make the code run faster on the selected machine but 337 somewhat slower on other machines. 338 This option only changes how the compiler emits instructions, not the 339 selection of instructions itself, so the resulting kernel will run on 340 all other machines. 341 342config TUNE_DEFAULT 343 bool "Default" 344 help 345 Tune the generated code for the target processor for which the kernel 346 will be compiled. 347 348config TUNE_Z900 349 bool "IBM zSeries model z800 and z900" 350 351config TUNE_Z990 352 bool "IBM zSeries model z890 and z990" 353 354config TUNE_Z9_109 355 bool "IBM System z9" 356 357config TUNE_Z10 358 bool "IBM System z10" 359 360config TUNE_Z196 361 bool "IBM zEnterprise 114 and 196" 362 363config TUNE_ZEC12 364 bool "IBM zBC12 and zEC12" 365 366config TUNE_Z13 367 bool "IBM z13" 368 369config TUNE_Z14 370 bool "IBM z14" 371 372endchoice 373 374config 64BIT 375 def_bool y 376 377config COMPAT 378 def_bool y 379 prompt "Kernel support for 31 bit emulation" 380 select COMPAT_BINFMT_ELF if BINFMT_ELF 381 select ARCH_WANT_OLD_COMPAT_IPC 382 select COMPAT_OLD_SIGACTION 383 select HAVE_UID16 384 depends on MULTIUSER 385 help 386 Select this option if you want to enable your system kernel to 387 handle system-calls from ELF binaries for 31 bit ESA. This option 388 (and some other stuff like libraries and such) is needed for 389 executing 31 bit applications. It is safe to say "Y". 390 391config SYSVIPC_COMPAT 392 def_bool y if COMPAT && SYSVIPC 393 394config SMP 395 def_bool y 396 prompt "Symmetric multi-processing support" 397 ---help--- 398 This enables support for systems with more than one CPU. If you have 399 a system with only one CPU, like most personal computers, say N. If 400 you have a system with more than one CPU, say Y. 401 402 If you say N here, the kernel will run on uni- and multiprocessor 403 machines, but will use only one CPU of a multiprocessor machine. If 404 you say Y here, the kernel will run on many, but not all, 405 uniprocessor machines. On a uniprocessor machine, the kernel 406 will run faster if you say N here. 407 408 See also the SMP-HOWTO available at 409 <http://www.tldp.org/docs.html#howto>. 410 411 Even if you don't know what to do here, say Y. 412 413config NR_CPUS 414 int "Maximum number of CPUs (2-512)" 415 range 2 512 416 depends on SMP 417 default "64" 418 help 419 This allows you to specify the maximum number of CPUs which this 420 kernel will support. The maximum supported value is 512 and the 421 minimum value which makes sense is 2. 422 423 This is purely to save memory - each supported CPU adds 424 approximately sixteen kilobytes to the kernel image. 425 426config HOTPLUG_CPU 427 def_bool y 428 prompt "Support for hot-pluggable CPUs" 429 depends on SMP 430 help 431 Say Y here to be able to turn CPUs off and on. CPUs 432 can be controlled through /sys/devices/system/cpu/cpu#. 433 Say N if you want to disable CPU hotplug. 434 435# Some NUMA nodes have memory ranges that span 436# other nodes. Even though a pfn is valid and 437# between a node's start and end pfns, it may not 438# reside on that node. See memmap_init_zone() 439# for details. <- They meant memory holes! 440config NODES_SPAN_OTHER_NODES 441 def_bool NUMA 442 443config NUMA 444 bool "NUMA support" 445 depends on SMP && SCHED_TOPOLOGY 446 default n 447 help 448 Enable NUMA support 449 450 This option adds NUMA support to the kernel. 451 452 An operation mode can be selected by appending 453 numa=<method> to the kernel command line. 454 455 The default behaviour is identical to appending numa=plain to 456 the command line. This will create just one node with all 457 available memory and all CPUs in it. 458 459config NODES_SHIFT 460 int "Maximum NUMA nodes (as a power of 2)" 461 range 1 10 462 depends on NUMA 463 default "4" 464 help 465 Specify the maximum number of NUMA nodes available on the target 466 system. Increases memory reserved to accommodate various tables. 467 468menu "Select NUMA modes" 469 depends on NUMA 470 471config NUMA_EMU 472 bool "NUMA emulation" 473 default y 474 help 475 Numa emulation mode will split the available system memory into 476 equal chunks which then are distributed over the configured number 477 of nodes in a round-robin manner. 478 479 The number of fake nodes is limited by the number of available memory 480 chunks (i.e. memory size / fake size) and the number of supported 481 nodes in the kernel. 482 483 The CPUs are assigned to the nodes in a way that partially respects 484 the original machine topology (if supported by the machine). 485 Fair distribution of the CPUs is not guaranteed. 486 487config EMU_SIZE 488 hex "NUMA emulation memory chunk size" 489 default 0x10000000 490 range 0x400000 0x100000000 491 depends on NUMA_EMU 492 help 493 Select the default size by which the memory is chopped and then 494 assigned to emulated NUMA nodes. 495 496 This can be overridden by specifying 497 498 emu_size=<n> 499 500 on the kernel command line where also suffixes K, M, G, and T are 501 supported. 502 503endmenu 504 505config SCHED_SMT 506 def_bool n 507 508config SCHED_MC 509 def_bool n 510 511config SCHED_BOOK 512 def_bool n 513 514config SCHED_DRAWER 515 def_bool n 516 517config SCHED_TOPOLOGY 518 def_bool y 519 prompt "Topology scheduler support" 520 depends on SMP 521 select SCHED_SMT 522 select SCHED_MC 523 select SCHED_BOOK 524 select SCHED_DRAWER 525 help 526 Topology scheduler support improves the CPU scheduler's decision 527 making when dealing with machines that have multi-threading, 528 multiple cores or multiple books. 529 530source "kernel/Kconfig.hz" 531 532config KEXEC 533 def_bool y 534 select KEXEC_CORE 535 536config KEXEC_FILE 537 bool "kexec file based system call" 538 select KEXEC_CORE 539 select BUILD_BIN2C 540 depends on CRYPTO 541 depends on CRYPTO_SHA256 542 depends on CRYPTO_SHA256_S390 543 help 544 Enable the kexec file based system call. In contrast to the normal 545 kexec system call this system call takes file descriptors for the 546 kernel and initramfs as arguments. 547 548config ARCH_HAS_KEXEC_PURGATORY 549 def_bool y 550 depends on KEXEC_FILE 551 552config ARCH_RANDOM 553 def_bool y 554 prompt "s390 architectural random number generation API" 555 help 556 Enable the s390 architectural random number generation API 557 to provide random data for all consumers within the Linux 558 kernel. 559 560 When enabled the arch_random_* functions declared in linux/random.h 561 are implemented. The implementation is based on the s390 CPACF 562 instruction subfunction TRNG which provides a real true random 563 number generator. 564 565 If unsure, say Y. 566 567config KERNEL_NOBP 568 def_bool n 569 prompt "Enable modified branch prediction for the kernel by default" 570 help 571 If this option is selected the kernel will switch to a modified 572 branch prediction mode if the firmware interface is available. 573 The modified branch prediction mode improves the behaviour in 574 regard to speculative execution. 575 576 With the option enabled the kernel parameter "nobp=0" or "nospec" 577 can be used to run the kernel in the normal branch prediction mode. 578 579 With the option disabled the modified branch prediction mode is 580 enabled with the "nobp=1" kernel parameter. 581 582 If unsure, say N. 583 584config EXPOLINE 585 def_bool n 586 prompt "Avoid speculative indirect branches in the kernel" 587 help 588 Compile the kernel with the expoline compiler options to guard 589 against kernel-to-user data leaks by avoiding speculative indirect 590 branches. 591 Requires a compiler with -mindirect-branch=thunk support for full 592 protection. The kernel may run slower. 593 594 If unsure, say N. 595 596choice 597 prompt "Expoline default" 598 depends on EXPOLINE 599 default EXPOLINE_FULL 600 601config EXPOLINE_OFF 602 bool "spectre_v2=off" 603 604config EXPOLINE_AUTO 605 bool "spectre_v2=auto" 606 607config EXPOLINE_FULL 608 bool "spectre_v2=on" 609 610endchoice 611 612endmenu 613 614menu "Memory setup" 615 616config ARCH_SPARSEMEM_ENABLE 617 def_bool y 618 select SPARSEMEM_VMEMMAP_ENABLE 619 select SPARSEMEM_VMEMMAP 620 621config ARCH_SPARSEMEM_DEFAULT 622 def_bool y 623 624config ARCH_SELECT_MEMORY_MODEL 625 def_bool y 626 627config ARCH_ENABLE_MEMORY_HOTPLUG 628 def_bool y if SPARSEMEM 629 630config ARCH_ENABLE_MEMORY_HOTREMOVE 631 def_bool y 632 633config ARCH_ENABLE_SPLIT_PMD_PTLOCK 634 def_bool y 635 636config FORCE_MAX_ZONEORDER 637 int 638 default "9" 639 640config MAX_PHYSMEM_BITS 641 int "Maximum size of supported physical memory in bits (42-53)" 642 range 42 53 643 default "46" 644 help 645 This option specifies the maximum supported size of physical memory 646 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB). 647 Increasing the number of bits also increases the kernel image size. 648 By default 46 bits (64TB) are supported. 649 650config PACK_STACK 651 def_bool y 652 prompt "Pack kernel stack" 653 help 654 This option enables the compiler option -mkernel-backchain if it 655 is available. If the option is available the compiler supports 656 the new stack layout which dramatically reduces the minimum stack 657 frame size. With an old compiler a non-leaf function needs a 658 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With 659 -mkernel-backchain the minimum size drops to 16 byte on 31 bit 660 and 24 byte on 64 bit. 661 662 Say Y if you are unsure. 663 664config CHECK_STACK 665 def_bool y 666 depends on !VMAP_STACK 667 prompt "Detect kernel stack overflow" 668 help 669 This option enables the compiler option -mstack-guard and 670 -mstack-size if they are available. If the compiler supports them 671 it will emit additional code to each function prolog to trigger 672 an illegal operation if the kernel stack is about to overflow. 673 674 Say N if you are unsure. 675 676config STACK_GUARD 677 int "Size of the guard area (128-1024)" 678 range 128 1024 679 depends on CHECK_STACK 680 default "256" 681 help 682 This allows you to specify the size of the guard area at the lower 683 end of the kernel stack. If the kernel stack points into the guard 684 area on function entry an illegal operation is triggered. The size 685 needs to be a power of 2. Please keep in mind that the size of an 686 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit. 687 The minimum size for the stack guard should be 256 for 31 bit and 688 512 for 64 bit. 689 690config WARN_DYNAMIC_STACK 691 def_bool n 692 prompt "Emit compiler warnings for function with dynamic stack usage" 693 help 694 This option enables the compiler option -mwarn-dynamicstack. If the 695 compiler supports this options generates warnings for functions 696 that dynamically allocate stack space using alloca. 697 698 Say N if you are unsure. 699 700endmenu 701 702menu "I/O subsystem" 703 704config QDIO 705 def_tristate y 706 prompt "QDIO support" 707 ---help--- 708 This driver provides the Queued Direct I/O base support for 709 IBM System z. 710 711 To compile this driver as a module, choose M here: the 712 module will be called qdio. 713 714 If unsure, say Y. 715 716if PCI 717 718config PCI_NR_FUNCTIONS 719 int "Maximum number of PCI functions (1-4096)" 720 range 1 4096 721 default "128" 722 help 723 This allows you to specify the maximum number of PCI functions which 724 this kernel will support. 725 726endif # PCI 727 728config HAS_IOMEM 729 def_bool PCI 730 731config CHSC_SCH 732 def_tristate m 733 prompt "Support for CHSC subchannels" 734 help 735 This driver allows usage of CHSC subchannels. A CHSC subchannel 736 is usually present on LPAR only. 737 The driver creates a device /dev/chsc, which may be used to 738 obtain I/O configuration information about the machine and 739 to issue asynchronous chsc commands (DANGEROUS). 740 You will usually only want to use this interface on a special 741 LPAR designated for system management. 742 743 To compile this driver as a module, choose M here: the 744 module will be called chsc_sch. 745 746 If unsure, say N. 747 748config SCM_BUS 749 def_bool y 750 prompt "SCM bus driver" 751 help 752 Bus driver for Storage Class Memory. 753 754config EADM_SCH 755 def_tristate m 756 prompt "Support for EADM subchannels" 757 depends on SCM_BUS 758 help 759 This driver allows usage of EADM subchannels. EADM subchannels act 760 as a communication vehicle for SCM increments. 761 762 To compile this driver as a module, choose M here: the 763 module will be called eadm_sch. 764 765config VFIO_CCW 766 def_tristate n 767 prompt "Support for VFIO-CCW subchannels" 768 depends on S390_CCW_IOMMU && VFIO_MDEV 769 help 770 This driver allows usage of I/O subchannels via VFIO-CCW. 771 772 To compile this driver as a module, choose M here: the 773 module will be called vfio_ccw. 774 775config VFIO_AP 776 def_tristate n 777 prompt "VFIO support for AP devices" 778 depends on S390_AP_IOMMU && VFIO_MDEV_DEVICE && KVM 779 help 780 This driver grants access to Adjunct Processor (AP) devices 781 via the VFIO mediated device interface. 782 783 To compile this driver as a module, choose M here: the module 784 will be called vfio_ap. 785 786endmenu 787 788menu "Dump support" 789 790config CRASH_DUMP 791 bool "kernel crash dumps" 792 depends on SMP 793 select KEXEC 794 help 795 Generate crash dump after being started by kexec. 796 Crash dump kernels are loaded in the main kernel with kexec-tools 797 into a specially reserved region and then later executed after 798 a crash by kdump/kexec. 799 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this. 800 This option also enables s390 zfcpdump. 801 See also <file:Documentation/s390/zfcpdump.txt> 802 803endmenu 804 805config SECCOMP 806 def_bool y 807 prompt "Enable seccomp to safely compute untrusted bytecode" 808 depends on PROC_FS 809 help 810 This kernel feature is useful for number crunching applications 811 that may need to compute untrusted bytecode during their 812 execution. By using pipes or other transports made available to 813 the process as file descriptors supporting the read/write 814 syscalls, it's possible to isolate those applications in 815 their own address space using seccomp. Once seccomp is 816 enabled via /proc/<pid>/seccomp, it cannot be disabled 817 and the task is only allowed to execute a few safe syscalls 818 defined by each seccomp mode. 819 820 If unsure, say Y. 821 822menu "Power Management" 823 824config ARCH_HIBERNATION_POSSIBLE 825 def_bool y 826 827source "kernel/power/Kconfig" 828 829endmenu 830 831config CCW 832 def_bool y 833 834config HAVE_PNETID 835 tristate 836 default (SMC || CCWGROUP) 837 838menu "Virtualization" 839 840config PFAULT 841 def_bool y 842 prompt "Pseudo page fault support" 843 help 844 Select this option, if you want to use PFAULT pseudo page fault 845 handling under VM. If running native or in LPAR, this option 846 has no effect. If your VM does not support PFAULT, PAGEEX 847 pseudo page fault handling will be used. 848 Note that VM 4.2 supports PFAULT but has a bug in its 849 implementation that causes some problems. 850 Everybody who wants to run Linux under VM != VM4.2 should select 851 this option. 852 853config CMM 854 def_tristate n 855 prompt "Cooperative memory management" 856 help 857 Select this option, if you want to enable the kernel interface 858 to reduce the memory size of the system. This is accomplished 859 by allocating pages of memory and put them "on hold". This only 860 makes sense for a system running under VM where the unused pages 861 will be reused by VM for other guest systems. The interface 862 allows an external monitor to balance memory of many systems. 863 Everybody who wants to run Linux under VM should select this 864 option. 865 866config CMM_IUCV 867 def_bool y 868 prompt "IUCV special message interface to cooperative memory management" 869 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV) 870 help 871 Select this option to enable the special message interface to 872 the cooperative memory management. 873 874config APPLDATA_BASE 875 def_bool n 876 prompt "Linux - VM Monitor Stream, base infrastructure" 877 depends on PROC_FS 878 help 879 This provides a kernel interface for creating and updating z/VM APPLDATA 880 monitor records. The monitor records are updated at certain time 881 intervals, once the timer is started. 882 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer, 883 i.e. enables or disables monitoring on the Linux side. 884 A custom interval value (in seconds) can be written to 885 /proc/appldata/interval. 886 887 Defaults are 60 seconds interval and timer off. 888 The /proc entries can also be read from, showing the current settings. 889 890config APPLDATA_MEM 891 def_tristate m 892 prompt "Monitor memory management statistics" 893 depends on APPLDATA_BASE && VM_EVENT_COUNTERS 894 help 895 This provides memory management related data to the Linux - VM Monitor 896 Stream, like paging/swapping rate, memory utilisation, etc. 897 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM 898 APPLDATA monitor record, i.e. enables or disables monitoring this record 899 on the z/VM side. 900 901 Default is disabled. 902 The /proc entry can also be read from, showing the current settings. 903 904 This can also be compiled as a module, which will be called 905 appldata_mem.o. 906 907config APPLDATA_OS 908 def_tristate m 909 prompt "Monitor OS statistics" 910 depends on APPLDATA_BASE 911 help 912 This provides OS related data to the Linux - VM Monitor Stream, like 913 CPU utilisation, etc. 914 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM 915 APPLDATA monitor record, i.e. enables or disables monitoring this record 916 on the z/VM side. 917 918 Default is disabled. 919 This can also be compiled as a module, which will be called 920 appldata_os.o. 921 922config APPLDATA_NET_SUM 923 def_tristate m 924 prompt "Monitor overall network statistics" 925 depends on APPLDATA_BASE && NET 926 help 927 This provides network related data to the Linux - VM Monitor Stream, 928 currently there is only a total sum of network I/O statistics, no 929 per-interface data. 930 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM 931 APPLDATA monitor record, i.e. enables or disables monitoring this record 932 on the z/VM side. 933 934 Default is disabled. 935 This can also be compiled as a module, which will be called 936 appldata_net_sum.o. 937 938config S390_HYPFS_FS 939 def_bool y 940 prompt "s390 hypervisor file system support" 941 select SYS_HYPERVISOR 942 help 943 This is a virtual file system intended to provide accounting 944 information in an s390 hypervisor environment. 945 946source "arch/s390/kvm/Kconfig" 947 948config S390_GUEST 949 def_bool y 950 prompt "s390 support for virtio devices" 951 select TTY 952 select VIRTUALIZATION 953 select VIRTIO 954 select VIRTIO_CONSOLE 955 help 956 Enabling this option adds support for virtio based paravirtual device 957 drivers on s390. 958 959 Select this option if you want to run the kernel as a guest under 960 the KVM hypervisor. 961 962endmenu 963