1# SPDX-License-Identifier: GPL-2.0 2config LOONGARCH 3 bool 4 default y 5 select ACPI 6 select ACPI_GENERIC_GSI if ACPI 7 select ACPI_MCFG if ACPI 8 select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU 9 select ACPI_PPTT if ACPI 10 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 11 select ARCH_BINFMT_ELF_STATE 12 select ARCH_DISABLE_KASAN_INLINE 13 select ARCH_ENABLE_MEMORY_HOTPLUG 14 select ARCH_ENABLE_MEMORY_HOTREMOVE 15 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 16 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 17 select ARCH_HAS_CPU_FINALIZE_INIT 18 select ARCH_HAS_CRC32 19 select ARCH_HAS_CURRENT_STACK_POINTER 20 select ARCH_HAS_DEBUG_VM_PGTABLE 21 select ARCH_HAS_FAST_MULTIPLIER 22 select ARCH_HAS_FORTIFY_SOURCE 23 select ARCH_HAS_KCOV 24 select ARCH_HAS_KERNEL_FPU_SUPPORT if CPU_HAS_FPU 25 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 26 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 27 select ARCH_HAS_PREEMPT_LAZY 28 select ARCH_HAS_PTE_DEVMAP 29 select ARCH_HAS_PTE_SPECIAL 30 select ARCH_HAS_SET_MEMORY 31 select ARCH_HAS_SET_DIRECT_MAP 32 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 33 select ARCH_HAS_UBSAN 34 select ARCH_HAS_VDSO_ARCH_DATA 35 select ARCH_INLINE_READ_LOCK if !PREEMPTION 36 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION 37 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION 38 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION 39 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION 40 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION 41 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION 42 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION 43 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION 44 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION 45 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION 46 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION 47 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION 48 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION 49 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION 50 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION 51 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION 52 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION 53 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION 54 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION 55 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION 56 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION 57 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION 58 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION 59 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION 60 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION 61 select ARCH_KEEP_MEMBLOCK 62 select ARCH_MIGHT_HAVE_PC_PARPORT 63 select ARCH_MIGHT_HAVE_PC_SERIO 64 select ARCH_SPARSEMEM_ENABLE 65 select ARCH_STACKWALK 66 select ARCH_SUPPORTS_ACPI 67 select ARCH_SUPPORTS_ATOMIC_RMW 68 select ARCH_SUPPORTS_HUGETLBFS 69 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 70 select ARCH_SUPPORTS_LTO_CLANG 71 select ARCH_SUPPORTS_LTO_CLANG_THIN 72 select ARCH_SUPPORTS_NUMA_BALANCING 73 select ARCH_SUPPORTS_RT 74 select ARCH_USE_BUILTIN_BSWAP 75 select ARCH_USE_CMPXCHG_LOCKREF 76 select ARCH_USE_QUEUED_RWLOCKS 77 select ARCH_USE_QUEUED_SPINLOCKS 78 select ARCH_WANT_DEFAULT_BPF_JIT 79 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 80 select ARCH_WANT_LD_ORPHAN_WARN 81 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP 82 select ARCH_WANTS_NO_INSTR 83 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE 84 select BUILDTIME_TABLE_SORT 85 select COMMON_CLK 86 select CPU_PM 87 select EDAC_SUPPORT 88 select EFI 89 select GENERIC_CLOCKEVENTS 90 select GENERIC_CMOS_UPDATE 91 select GENERIC_CPU_AUTOPROBE 92 select GENERIC_CPU_DEVICES 93 select GENERIC_CPU_VULNERABILITIES 94 select GENERIC_ENTRY 95 select GENERIC_GETTIMEOFDAY 96 select GENERIC_IOREMAP if !ARCH_IOREMAP 97 select GENERIC_IRQ_MATRIX_ALLOCATOR 98 select GENERIC_IRQ_MULTI_HANDLER 99 select GENERIC_IRQ_PROBE 100 select GENERIC_IRQ_SHOW 101 select GENERIC_LIB_ASHLDI3 102 select GENERIC_LIB_ASHRDI3 103 select GENERIC_LIB_CMPDI2 104 select GENERIC_LIB_LSHRDI3 105 select GENERIC_LIB_UCMPDI2 106 select GENERIC_LIB_DEVMEM_IS_ALLOWED 107 select GENERIC_PCI_IOMAP 108 select GENERIC_SCHED_CLOCK 109 select GENERIC_SMP_IDLE_THREAD 110 select GENERIC_TIME_VSYSCALL 111 select GENERIC_VDSO_DATA_STORE 112 select GENERIC_VDSO_TIME_NS 113 select GPIOLIB 114 select HAS_IOPORT 115 select HAVE_ARCH_AUDITSYSCALL 116 select HAVE_ARCH_JUMP_LABEL 117 select HAVE_ARCH_JUMP_LABEL_RELATIVE 118 select HAVE_ARCH_KASAN 119 select HAVE_ARCH_KFENCE 120 select HAVE_ARCH_KGDB if PERF_EVENTS 121 select HAVE_ARCH_MMAP_RND_BITS if MMU 122 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 123 select HAVE_ARCH_SECCOMP 124 select HAVE_ARCH_SECCOMP_FILTER 125 select HAVE_ARCH_TRACEHOOK 126 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 127 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 128 select HAVE_ASM_MODVERSIONS 129 select HAVE_CONTEXT_TRACKING_USER 130 select HAVE_C_RECORDMCOUNT 131 select HAVE_DEBUG_KMEMLEAK 132 select HAVE_DEBUG_STACKOVERFLOW 133 select HAVE_DMA_CONTIGUOUS 134 select HAVE_DYNAMIC_FTRACE 135 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 136 select HAVE_FTRACE_REGS_HAVING_PT_REGS 137 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 138 select HAVE_DYNAMIC_FTRACE_WITH_REGS 139 select HAVE_EBPF_JIT 140 select HAVE_EFFICIENT_UNALIGNED_ACCESS if !ARCH_STRICT_ALIGN 141 select HAVE_EXIT_THREAD 142 select HAVE_GUP_FAST 143 select HAVE_FTRACE_GRAPH_FUNC 144 select HAVE_FTRACE_MCOUNT_RECORD 145 select HAVE_FUNCTION_ARG_ACCESS_API 146 select HAVE_FUNCTION_ERROR_INJECTION 147 select HAVE_FUNCTION_GRAPH_FREGS 148 select HAVE_FUNCTION_GRAPH_TRACER 149 select HAVE_FUNCTION_TRACER 150 select HAVE_GCC_PLUGINS 151 select HAVE_GENERIC_VDSO 152 select HAVE_HW_BREAKPOINT if PERF_EVENTS 153 select HAVE_IOREMAP_PROT 154 select HAVE_IRQ_EXIT_ON_IRQ_STACK 155 select HAVE_IRQ_TIME_ACCOUNTING 156 select HAVE_KPROBES 157 select HAVE_KPROBES_ON_FTRACE 158 select HAVE_KRETPROBES 159 select HAVE_LIVEPATCH 160 select HAVE_MOD_ARCH_SPECIFIC 161 select HAVE_NMI 162 select HAVE_OBJTOOL if AS_HAS_EXPLICIT_RELOCS && AS_HAS_THIN_ADD_SUB 163 select HAVE_PCI 164 select HAVE_PERF_EVENTS 165 select HAVE_PERF_REGS 166 select HAVE_PERF_USER_STACK_DUMP 167 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 168 select HAVE_PREEMPT_DYNAMIC_KEY 169 select HAVE_REGS_AND_STACK_ACCESS_API 170 select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC 171 select HAVE_RETHOOK 172 select HAVE_RSEQ 173 select HAVE_RUST 174 select HAVE_SAMPLE_FTRACE_DIRECT 175 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 176 select HAVE_SETUP_PER_CPU_AREA if NUMA 177 select HAVE_STACK_VALIDATION if HAVE_OBJTOOL 178 select HAVE_STACKPROTECTOR 179 select HAVE_SYSCALL_TRACEPOINTS 180 select HAVE_TIF_NOHZ 181 select HAVE_VIRT_CPU_ACCOUNTING_GEN 182 select IRQ_FORCED_THREADING 183 select IRQ_LOONGARCH_CPU 184 select LOCK_MM_AND_FIND_VMA 185 select MMU_GATHER_MERGE_VMAS if MMU 186 select MODULES_USE_ELF_RELA if MODULES 187 select NEED_PER_CPU_EMBED_FIRST_CHUNK 188 select NEED_PER_CPU_PAGE_FIRST_CHUNK 189 select OF 190 select OF_EARLY_FLATTREE 191 select PCI 192 select PCI_DOMAINS_GENERIC 193 select PCI_ECAM if ACPI 194 select PCI_LOONGSON 195 select PCI_MSI_ARCH_FALLBACKS 196 select PCI_QUIRKS 197 select PERF_USE_VMALLOC 198 select RTC_LIB 199 select SPARSE_IRQ 200 select SYSCTL_ARCH_UNALIGN_ALLOW 201 select SYSCTL_ARCH_UNALIGN_NO_WARN 202 select SYSCTL_EXCEPTION_TRACE 203 select SWIOTLB 204 select TRACE_IRQFLAGS_SUPPORT 205 select USE_PERCPU_NUMA_NODE_ID 206 select USER_STACKTRACE_SUPPORT 207 select VDSO_GETRANDOM 208 select ZONE_DMA32 209 210config 32BIT 211 bool 212 213config 64BIT 214 def_bool y 215 216config GENERIC_BUG 217 def_bool y 218 depends on BUG 219 220config GENERIC_BUG_RELATIVE_POINTERS 221 def_bool y 222 depends on GENERIC_BUG 223 224config GENERIC_CALIBRATE_DELAY 225 def_bool y 226 227config GENERIC_CSUM 228 def_bool y 229 230config GENERIC_HWEIGHT 231 def_bool y 232 233config L1_CACHE_SHIFT 234 int 235 default "6" 236 237config LOCKDEP_SUPPORT 238 bool 239 default y 240 241config STACKTRACE_SUPPORT 242 bool 243 default y 244 245# MACH_LOONGSON32 and MACH_LOONGSON64 are deliberately carried over from the 246# MIPS Loongson code, to preserve Loongson-specific code paths in drivers that 247# are shared between architectures, and specifically expecting the symbols. 248config MACH_LOONGSON32 249 def_bool 32BIT 250 251config MACH_LOONGSON64 252 def_bool 64BIT 253 254config FIX_EARLYCON_MEM 255 def_bool !ARCH_IOREMAP 256 257config PGTABLE_2LEVEL 258 bool 259 260config PGTABLE_3LEVEL 261 bool 262 263config PGTABLE_4LEVEL 264 bool 265 266config PGTABLE_LEVELS 267 int 268 default 2 if PGTABLE_2LEVEL 269 default 3 if PGTABLE_3LEVEL 270 default 4 if PGTABLE_4LEVEL 271 272config SCHED_OMIT_FRAME_POINTER 273 bool 274 default y 275 276config AS_HAS_EXPLICIT_RELOCS 277 def_bool $(as-instr,x:pcalau12i \$t0$(comma)%pc_hi20(x)) 278 279config AS_HAS_FCSR_CLASS 280 def_bool $(as-instr,movfcsr2gr \$t0$(comma)\$fcsr0) 281 282config AS_HAS_THIN_ADD_SUB 283 def_bool $(cc-option,-Wa$(comma)-mthin-add-sub) || AS_IS_LLVM 284 285config AS_HAS_LSX_EXTENSION 286 def_bool $(as-instr,vld \$vr0$(comma)\$a0$(comma)0) 287 288config AS_HAS_LASX_EXTENSION 289 def_bool $(as-instr,xvld \$xr0$(comma)\$a0$(comma)0) 290 291config AS_HAS_LBT_EXTENSION 292 def_bool $(as-instr,movscr2gr \$a0$(comma)\$scr0) 293 294config AS_HAS_LVZ_EXTENSION 295 def_bool $(as-instr,hvcl 0) 296 297config CC_HAS_ANNOTATE_TABLEJUMP 298 def_bool $(cc-option,-mannotate-tablejump) 299 300menu "Kernel type and options" 301 302source "kernel/Kconfig.hz" 303 304choice 305 prompt "Page Table Layout" 306 default 16KB_2LEVEL if 32BIT 307 default 16KB_3LEVEL if 64BIT 308 help 309 Allows choosing the page table layout, which is a combination 310 of page size and page table levels. The size of virtual memory 311 address space are determined by the page table layout. 312 313config 4KB_3LEVEL 314 bool "4KB with 3 levels" 315 select HAVE_PAGE_SIZE_4KB 316 select PGTABLE_3LEVEL 317 help 318 This option selects 4KB page size with 3 level page tables, which 319 support a maximum of 39 bits of application virtual memory. 320 321config 4KB_4LEVEL 322 bool "4KB with 4 levels" 323 select HAVE_PAGE_SIZE_4KB 324 select PGTABLE_4LEVEL 325 help 326 This option selects 4KB page size with 4 level page tables, which 327 support a maximum of 48 bits of application virtual memory. 328 329config 16KB_2LEVEL 330 bool "16KB with 2 levels" 331 select HAVE_PAGE_SIZE_16KB 332 select PGTABLE_2LEVEL 333 help 334 This option selects 16KB page size with 2 level page tables, which 335 support a maximum of 36 bits of application virtual memory. 336 337config 16KB_3LEVEL 338 bool "16KB with 3 levels" 339 select HAVE_PAGE_SIZE_16KB 340 select PGTABLE_3LEVEL 341 help 342 This option selects 16KB page size with 3 level page tables, which 343 support a maximum of 47 bits of application virtual memory. 344 345config 64KB_2LEVEL 346 bool "64KB with 2 levels" 347 select HAVE_PAGE_SIZE_64KB 348 select PGTABLE_2LEVEL 349 help 350 This option selects 64KB page size with 2 level page tables, which 351 support a maximum of 42 bits of application virtual memory. 352 353config 64KB_3LEVEL 354 bool "64KB with 3 levels" 355 select HAVE_PAGE_SIZE_64KB 356 select PGTABLE_3LEVEL 357 help 358 This option selects 64KB page size with 3 level page tables, which 359 support a maximum of 55 bits of application virtual memory. 360 361endchoice 362 363config CMDLINE 364 string "Built-in kernel command line" 365 help 366 For most platforms, the arguments for the kernel's command line 367 are provided at run-time, during boot. However, there are cases 368 where either no arguments are being provided or the provided 369 arguments are insufficient or even invalid. 370 371 When that occurs, it is possible to define a built-in command 372 line here and choose how the kernel should use it later on. 373 374choice 375 prompt "Kernel command line type" 376 default CMDLINE_BOOTLOADER 377 help 378 Choose how the kernel will handle the provided built-in command 379 line. 380 381config CMDLINE_BOOTLOADER 382 bool "Use bootloader kernel arguments if available" 383 help 384 Prefer the command-line passed by the boot loader if available. 385 Use the built-in command line as fallback in case we get nothing 386 during boot. This is the default behaviour. 387 388config CMDLINE_EXTEND 389 bool "Use built-in to extend bootloader kernel arguments" 390 help 391 The built-in command line will be appended to the command- 392 line arguments provided during boot. This is useful in 393 cases where the provided arguments are insufficient and 394 you don't want to or cannot modify them. 395 396config CMDLINE_FORCE 397 bool "Always use the built-in kernel command string" 398 help 399 Always use the built-in command line, even if we get one during 400 boot. This is useful in case you need to override the provided 401 command line on systems where you don't have or want control 402 over it. 403 404endchoice 405 406config BUILTIN_DTB 407 bool "Enable built-in dtb in kernel" 408 depends on OF 409 select GENERIC_BUILTIN_DTB 410 help 411 Some existing systems do not provide a canonical device tree to 412 the kernel at boot time. Let's provide a device tree table in the 413 kernel, keyed by the dts filename, containing the relevant DTBs. 414 415 Built-in DTBs are generic enough and can be used as references. 416 417config BUILTIN_DTB_NAME 418 string "Source file for built-in dtb" 419 depends on BUILTIN_DTB 420 help 421 Base name (without suffix, relative to arch/loongarch/boot/dts/) 422 for the DTS file that will be used to produce the DTB linked into 423 the kernel. 424 425config DMI 426 bool "Enable DMI scanning" 427 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 428 default y 429 help 430 This enables SMBIOS/DMI feature for systems, and scanning of 431 DMI to identify machine quirks. 432 433config EFI 434 bool "EFI runtime service support" 435 select UCS2_STRING 436 select EFI_RUNTIME_WRAPPERS 437 help 438 This enables the kernel to use EFI runtime services that are 439 available (such as the EFI variable services). 440 441config EFI_STUB 442 bool "EFI boot stub support" 443 default y 444 depends on EFI 445 select EFI_GENERIC_STUB 446 help 447 This kernel feature allows the kernel to be loaded directly by 448 EFI firmware without the use of a bootloader. 449 450config SCHED_SMT 451 bool "SMT scheduler support" 452 depends on SMP 453 default y 454 help 455 Improves scheduler's performance when there are multiple 456 threads in one physical core. 457 458config SMP 459 bool "Multi-Processing support" 460 help 461 This enables support for systems with more than one CPU. If you have 462 a system with only one CPU, say N. If you have a system with more 463 than one CPU, say Y. 464 465 If you say N here, the kernel will run on uni- and multiprocessor 466 machines, but will use only one CPU of a multiprocessor machine. If 467 you say Y here, the kernel will run on many, but not all, 468 uniprocessor machines. On a uniprocessor machine, the kernel 469 will run faster if you say N here. 470 471 See also the SMP-HOWTO available at <http://www.tldp.org/docs.html#howto>. 472 473 If you don't know what to do here, say N. 474 475config HOTPLUG_CPU 476 bool "Support for hot-pluggable CPUs" 477 depends on SMP 478 select GENERIC_IRQ_MIGRATION 479 help 480 Say Y here to allow turning CPUs off and on. CPUs can be 481 controlled through /sys/devices/system/cpu. 482 (Note: power management support will enable this option 483 automatically on SMP systems. ) 484 Say N if you want to disable CPU hotplug. 485 486config NR_CPUS 487 int "Maximum number of CPUs (2-256)" 488 range 2 256 489 depends on SMP 490 default "64" 491 help 492 This allows you to specify the maximum number of CPUs which this 493 kernel will support. 494 495config NUMA 496 bool "NUMA Support" 497 select SMP 498 help 499 Say Y to compile the kernel with NUMA (Non-Uniform Memory Access) 500 support. This option improves performance on systems with more 501 than one NUMA node; on single node systems it is generally better 502 to leave it disabled. 503 504config NODES_SHIFT 505 int 506 default "6" 507 depends on NUMA 508 509config ARCH_FORCE_MAX_ORDER 510 int "Maximum zone order" 511 default "13" if PAGE_SIZE_64KB 512 default "11" if PAGE_SIZE_16KB 513 default "10" 514 help 515 The kernel memory allocator divides physically contiguous memory 516 blocks into "zones", where each zone is a power of two number of 517 pages. This option selects the largest power of two that the kernel 518 keeps in the memory allocator. If you need to allocate very large 519 blocks of physically contiguous memory, then you may need to 520 increase this value. 521 522 The page size is not necessarily 4KB. Keep this in mind 523 when choosing a value for this option. 524 525config ARCH_IOREMAP 526 bool "Enable LoongArch DMW-based ioremap()" 527 help 528 We use generic TLB-based ioremap() by default since it has page 529 protection support. However, you can enable LoongArch DMW-based 530 ioremap() for better performance. 531 532config ARCH_WRITECOMBINE 533 bool "Enable WriteCombine (WUC) for ioremap()" 534 help 535 LoongArch maintains cache coherency in hardware, but when paired 536 with LS7A chipsets the WUC attribute (Weak-ordered UnCached, which 537 is similar to WriteCombine) is out of the scope of cache coherency 538 machanism for PCIe devices (this is a PCIe protocol violation, which 539 may be fixed in newer chipsets). 540 541 This means WUC can only used for write-only memory regions now, so 542 this option is disabled by default, making WUC silently fallback to 543 SUC for ioremap(). You can enable this option if the kernel is ensured 544 to run on hardware without this bug. 545 546 You can override this setting via writecombine=on/off boot parameter. 547 548config ARCH_STRICT_ALIGN 549 bool "Enable -mstrict-align to prevent unaligned accesses" if EXPERT 550 default y 551 help 552 Not all LoongArch cores support h/w unaligned access, we can use 553 -mstrict-align build parameter to prevent unaligned accesses. 554 555 CPUs with h/w unaligned access support: 556 Loongson-2K2000/2K3000/3A5000/3C5000/3D5000. 557 558 CPUs without h/w unaligned access support: 559 Loongson-2K500/2K1000. 560 561 This option is enabled by default to make the kernel be able to run 562 on all LoongArch systems. But you can disable it manually if you want 563 to run kernel only on systems with h/w unaligned access support in 564 order to optimise for performance. 565 566config CPU_HAS_FPU 567 bool 568 default y 569 570config CPU_HAS_LSX 571 bool "Support for the Loongson SIMD Extension" 572 depends on AS_HAS_LSX_EXTENSION 573 help 574 Loongson SIMD Extension (LSX) introduces 128 bit wide vector registers 575 and a set of SIMD instructions to operate on them. When this option 576 is enabled the kernel will support allocating & switching LSX 577 vector register contexts. If you know that your kernel will only be 578 running on CPUs which do not support LSX or that your userland will 579 not be making use of it then you may wish to say N here to reduce 580 the size & complexity of your kernel. 581 582 If unsure, say Y. 583 584config CPU_HAS_LASX 585 bool "Support for the Loongson Advanced SIMD Extension" 586 depends on CPU_HAS_LSX 587 depends on AS_HAS_LASX_EXTENSION 588 help 589 Loongson Advanced SIMD Extension (LASX) introduces 256 bit wide vector 590 registers and a set of SIMD instructions to operate on them. When this 591 option is enabled the kernel will support allocating & switching LASX 592 vector register contexts. If you know that your kernel will only be 593 running on CPUs which do not support LASX or that your userland will 594 not be making use of it then you may wish to say N here to reduce 595 the size & complexity of your kernel. 596 597 If unsure, say Y. 598 599config CPU_HAS_LBT 600 bool "Support for the Loongson Binary Translation Extension" 601 depends on AS_HAS_LBT_EXTENSION 602 help 603 Loongson Binary Translation (LBT) introduces 4 scratch registers (SCR0 604 to SCR3), x86/ARM eflags (eflags) and x87 fpu stack pointer (ftop). 605 Enabling this option allows the kernel to allocate and switch registers 606 specific to LBT. 607 608 If you want to use this feature, such as the Loongson Architecture 609 Translator (LAT), say Y. 610 611config CPU_HAS_PREFETCH 612 bool 613 default y 614 615config ARCH_SUPPORTS_KEXEC 616 def_bool y 617 618config ARCH_SUPPORTS_CRASH_DUMP 619 def_bool y 620 621config ARCH_DEFAULT_CRASH_DUMP 622 def_bool y 623 624config ARCH_SELECTS_CRASH_DUMP 625 def_bool y 626 depends on CRASH_DUMP 627 select RELOCATABLE 628 629config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 630 def_bool CRASH_RESERVE 631 632config RELOCATABLE 633 bool "Relocatable kernel" 634 select ARCH_HAS_RELR 635 help 636 This builds the kernel as a Position Independent Executable (PIE), 637 which retains all relocation metadata required, so as to relocate 638 the kernel binary at runtime to a different virtual address from 639 its link address. 640 641config RANDOMIZE_BASE 642 bool "Randomize the address of the kernel (KASLR)" 643 depends on RELOCATABLE 644 help 645 Randomizes the physical and virtual address at which the 646 kernel image is loaded, as a security feature that 647 deters exploit attempts relying on knowledge of the location 648 of kernel internals. 649 650 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET. 651 652 If unsure, say N. 653 654config RANDOMIZE_BASE_MAX_OFFSET 655 hex "Maximum KASLR offset" if EXPERT 656 depends on RANDOMIZE_BASE 657 range 0x0 0x10000000 658 default "0x01000000" 659 help 660 When KASLR is active, this provides the maximum offset that will 661 be applied to the kernel image. It should be set according to the 662 amount of physical RAM available in the target system. 663 664 This is limited by the size of the lower address memory, 256MB. 665 666source "kernel/livepatch/Kconfig" 667 668config PARAVIRT 669 bool "Enable paravirtualization code" 670 depends on AS_HAS_LVZ_EXTENSION 671 help 672 This changes the kernel so it can modify itself when it is run 673 under a hypervisor, potentially improving performance significantly 674 over full virtualization. However, when run without a hypervisor 675 the kernel is theoretically slower and slightly larger. 676 677config PARAVIRT_TIME_ACCOUNTING 678 bool "Paravirtual steal time accounting" 679 depends on PARAVIRT 680 help 681 Select this option to enable fine granularity task steal time 682 accounting. Time spent executing other tasks in parallel with 683 the current vCPU is discounted from the vCPU power. To account for 684 that, there can be a small performance impact. 685 686 If in doubt, say N here. 687 688endmenu 689 690config ARCH_SELECT_MEMORY_MODEL 691 def_bool y 692 693config ARCH_FLATMEM_ENABLE 694 def_bool y 695 depends on !NUMA 696 697config ARCH_SPARSEMEM_ENABLE 698 def_bool y 699 select SPARSEMEM_VMEMMAP_ENABLE 700 help 701 Say Y to support efficient handling of sparse physical memory, 702 for architectures which are either NUMA (Non-Uniform Memory Access) 703 or have huge holes in the physical address space for other reasons. 704 See <file:Documentation/mm/numa.rst> for more. 705 706config ARCH_MEMORY_PROBE 707 def_bool y 708 depends on MEMORY_HOTPLUG 709 710config MMU 711 bool 712 default y 713 714config ARCH_MMAP_RND_BITS_MIN 715 default 12 716 717config ARCH_MMAP_RND_BITS_MAX 718 default 18 719 720config ARCH_SUPPORTS_UPROBES 721 def_bool y 722 723config KASAN_SHADOW_OFFSET 724 hex 725 default 0x0 726 depends on KASAN 727 728menu "Power management options" 729 730config ARCH_SUSPEND_POSSIBLE 731 def_bool y 732 733config ARCH_HIBERNATION_POSSIBLE 734 def_bool y 735 736source "kernel/power/Kconfig" 737source "drivers/acpi/Kconfig" 738source "drivers/cpufreq/Kconfig" 739 740endmenu 741 742source "arch/loongarch/kvm/Kconfig" 743