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_MEMTEST 77 select ARCH_USE_QUEUED_RWLOCKS 78 select ARCH_USE_QUEUED_SPINLOCKS 79 select ARCH_WANT_DEFAULT_BPF_JIT 80 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 81 select ARCH_WANT_LD_ORPHAN_WARN 82 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP 83 select ARCH_WANTS_NO_INSTR 84 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE 85 select BUILDTIME_TABLE_SORT 86 select COMMON_CLK 87 select CPU_PM 88 select EDAC_SUPPORT 89 select EFI 90 select GENERIC_CLOCKEVENTS 91 select GENERIC_CMOS_UPDATE 92 select GENERIC_CPU_AUTOPROBE 93 select GENERIC_CPU_DEVICES 94 select GENERIC_CPU_VULNERABILITIES 95 select GENERIC_ENTRY 96 select GENERIC_GETTIMEOFDAY 97 select GENERIC_IOREMAP if !ARCH_IOREMAP 98 select GENERIC_IRQ_MATRIX_ALLOCATOR 99 select GENERIC_IRQ_MULTI_HANDLER 100 select GENERIC_IRQ_PROBE 101 select GENERIC_IRQ_SHOW 102 select GENERIC_LIB_ASHLDI3 103 select GENERIC_LIB_ASHRDI3 104 select GENERIC_LIB_CMPDI2 105 select GENERIC_LIB_LSHRDI3 106 select GENERIC_LIB_UCMPDI2 107 select GENERIC_LIB_DEVMEM_IS_ALLOWED 108 select GENERIC_PCI_IOMAP 109 select GENERIC_SCHED_CLOCK 110 select GENERIC_SMP_IDLE_THREAD 111 select GENERIC_TIME_VSYSCALL 112 select GENERIC_VDSO_DATA_STORE 113 select GENERIC_VDSO_TIME_NS 114 select GPIOLIB 115 select HAS_IOPORT 116 select HAVE_ARCH_AUDITSYSCALL 117 select HAVE_ARCH_JUMP_LABEL 118 select HAVE_ARCH_JUMP_LABEL_RELATIVE 119 select HAVE_ARCH_KASAN 120 select HAVE_ARCH_KFENCE 121 select HAVE_ARCH_KGDB if PERF_EVENTS 122 select HAVE_ARCH_MMAP_RND_BITS if MMU 123 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 124 select HAVE_ARCH_SECCOMP 125 select HAVE_ARCH_SECCOMP_FILTER 126 select HAVE_ARCH_TRACEHOOK 127 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 128 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 129 select HAVE_ASM_MODVERSIONS 130 select HAVE_CONTEXT_TRACKING_USER 131 select HAVE_C_RECORDMCOUNT 132 select HAVE_DEBUG_KMEMLEAK 133 select HAVE_DEBUG_STACKOVERFLOW 134 select HAVE_DMA_CONTIGUOUS 135 select HAVE_DYNAMIC_FTRACE 136 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 137 select HAVE_FTRACE_REGS_HAVING_PT_REGS 138 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 139 select HAVE_DYNAMIC_FTRACE_WITH_REGS 140 select HAVE_EBPF_JIT 141 select HAVE_EFFICIENT_UNALIGNED_ACCESS if !ARCH_STRICT_ALIGN 142 select HAVE_EXIT_THREAD 143 select HAVE_GUP_FAST 144 select HAVE_FTRACE_GRAPH_FUNC 145 select HAVE_FTRACE_MCOUNT_RECORD 146 select HAVE_FUNCTION_ARG_ACCESS_API 147 select HAVE_FUNCTION_ERROR_INJECTION 148 select HAVE_FUNCTION_GRAPH_FREGS 149 select HAVE_FUNCTION_GRAPH_TRACER 150 select HAVE_FUNCTION_TRACER 151 select HAVE_GCC_PLUGINS 152 select HAVE_GENERIC_VDSO 153 select HAVE_HW_BREAKPOINT if PERF_EVENTS 154 select HAVE_IOREMAP_PROT 155 select HAVE_IRQ_EXIT_ON_IRQ_STACK 156 select HAVE_IRQ_TIME_ACCOUNTING 157 select HAVE_KPROBES 158 select HAVE_KPROBES_ON_FTRACE 159 select HAVE_KRETPROBES 160 select HAVE_LIVEPATCH 161 select HAVE_MOD_ARCH_SPECIFIC 162 select HAVE_NMI 163 select HAVE_OBJTOOL if AS_HAS_EXPLICIT_RELOCS && AS_HAS_THIN_ADD_SUB 164 select HAVE_PCI 165 select HAVE_PERF_EVENTS 166 select HAVE_PERF_REGS 167 select HAVE_PERF_USER_STACK_DUMP 168 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 169 select HAVE_PREEMPT_DYNAMIC_KEY 170 select HAVE_REGS_AND_STACK_ACCESS_API 171 select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC 172 select HAVE_RETHOOK 173 select HAVE_RSEQ 174 select HAVE_RUST 175 select HAVE_SAMPLE_FTRACE_DIRECT 176 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 177 select HAVE_SETUP_PER_CPU_AREA if NUMA 178 select HAVE_STACK_VALIDATION if HAVE_OBJTOOL 179 select HAVE_STACKPROTECTOR 180 select HAVE_SYSCALL_TRACEPOINTS 181 select HAVE_TIF_NOHZ 182 select HAVE_VIRT_CPU_ACCOUNTING_GEN 183 select IRQ_FORCED_THREADING 184 select IRQ_LOONGARCH_CPU 185 select LOCK_MM_AND_FIND_VMA 186 select MMU_GATHER_MERGE_VMAS if MMU 187 select MODULES_USE_ELF_RELA if MODULES 188 select NEED_PER_CPU_EMBED_FIRST_CHUNK 189 select NEED_PER_CPU_PAGE_FIRST_CHUNK 190 select OF 191 select OF_EARLY_FLATTREE 192 select PCI 193 select PCI_DOMAINS_GENERIC 194 select PCI_ECAM if ACPI 195 select PCI_LOONGSON 196 select PCI_MSI_ARCH_FALLBACKS 197 select PCI_QUIRKS 198 select PERF_USE_VMALLOC 199 select RTC_LIB 200 select SPARSE_IRQ 201 select SYSCTL_ARCH_UNALIGN_ALLOW 202 select SYSCTL_ARCH_UNALIGN_NO_WARN 203 select SYSCTL_EXCEPTION_TRACE 204 select SWIOTLB 205 select TRACE_IRQFLAGS_SUPPORT 206 select USE_PERCPU_NUMA_NODE_ID 207 select USER_STACKTRACE_SUPPORT 208 select VDSO_GETRANDOM 209 select ZONE_DMA32 210 211config 32BIT 212 bool 213 214config 64BIT 215 def_bool y 216 217config GENERIC_BUG 218 def_bool y 219 depends on BUG 220 221config GENERIC_BUG_RELATIVE_POINTERS 222 def_bool y 223 depends on GENERIC_BUG 224 225config GENERIC_CALIBRATE_DELAY 226 def_bool y 227 228config GENERIC_CSUM 229 def_bool y 230 231config GENERIC_HWEIGHT 232 def_bool y 233 234config L1_CACHE_SHIFT 235 int 236 default "6" 237 238config LOCKDEP_SUPPORT 239 bool 240 default y 241 242config STACKTRACE_SUPPORT 243 bool 244 default y 245 246# MACH_LOONGSON32 and MACH_LOONGSON64 are deliberately carried over from the 247# MIPS Loongson code, to preserve Loongson-specific code paths in drivers that 248# are shared between architectures, and specifically expecting the symbols. 249config MACH_LOONGSON32 250 def_bool 32BIT 251 252config MACH_LOONGSON64 253 def_bool 64BIT 254 255config FIX_EARLYCON_MEM 256 def_bool !ARCH_IOREMAP 257 258config PGTABLE_2LEVEL 259 bool 260 261config PGTABLE_3LEVEL 262 bool 263 264config PGTABLE_4LEVEL 265 bool 266 267config PGTABLE_LEVELS 268 int 269 default 2 if PGTABLE_2LEVEL 270 default 3 if PGTABLE_3LEVEL 271 default 4 if PGTABLE_4LEVEL 272 273config SCHED_OMIT_FRAME_POINTER 274 bool 275 default y 276 277config AS_HAS_EXPLICIT_RELOCS 278 def_bool $(as-instr,x:pcalau12i \$t0$(comma)%pc_hi20(x)) 279 280config AS_HAS_FCSR_CLASS 281 def_bool $(as-instr,movfcsr2gr \$t0$(comma)\$fcsr0) 282 283config AS_HAS_THIN_ADD_SUB 284 def_bool $(cc-option,-Wa$(comma)-mthin-add-sub) || AS_IS_LLVM 285 286config AS_HAS_LSX_EXTENSION 287 def_bool $(as-instr,vld \$vr0$(comma)\$a0$(comma)0) 288 289config AS_HAS_LASX_EXTENSION 290 def_bool $(as-instr,xvld \$xr0$(comma)\$a0$(comma)0) 291 292config AS_HAS_LBT_EXTENSION 293 def_bool $(as-instr,movscr2gr \$a0$(comma)\$scr0) 294 295config AS_HAS_LVZ_EXTENSION 296 def_bool $(as-instr,hvcl 0) 297 298config CC_HAS_ANNOTATE_TABLEJUMP 299 def_bool $(cc-option,-mannotate-tablejump) 300 301menu "Kernel type and options" 302 303source "kernel/Kconfig.hz" 304 305choice 306 prompt "Page Table Layout" 307 default 16KB_2LEVEL if 32BIT 308 default 16KB_3LEVEL if 64BIT 309 help 310 Allows choosing the page table layout, which is a combination 311 of page size and page table levels. The size of virtual memory 312 address space are determined by the page table layout. 313 314config 4KB_3LEVEL 315 bool "4KB with 3 levels" 316 select HAVE_PAGE_SIZE_4KB 317 select PGTABLE_3LEVEL 318 help 319 This option selects 4KB page size with 3 level page tables, which 320 support a maximum of 39 bits of application virtual memory. 321 322config 4KB_4LEVEL 323 bool "4KB with 4 levels" 324 select HAVE_PAGE_SIZE_4KB 325 select PGTABLE_4LEVEL 326 help 327 This option selects 4KB page size with 4 level page tables, which 328 support a maximum of 48 bits of application virtual memory. 329 330config 16KB_2LEVEL 331 bool "16KB with 2 levels" 332 select HAVE_PAGE_SIZE_16KB 333 select PGTABLE_2LEVEL 334 help 335 This option selects 16KB page size with 2 level page tables, which 336 support a maximum of 36 bits of application virtual memory. 337 338config 16KB_3LEVEL 339 bool "16KB with 3 levels" 340 select HAVE_PAGE_SIZE_16KB 341 select PGTABLE_3LEVEL 342 help 343 This option selects 16KB page size with 3 level page tables, which 344 support a maximum of 47 bits of application virtual memory. 345 346config 64KB_2LEVEL 347 bool "64KB with 2 levels" 348 select HAVE_PAGE_SIZE_64KB 349 select PGTABLE_2LEVEL 350 help 351 This option selects 64KB page size with 2 level page tables, which 352 support a maximum of 42 bits of application virtual memory. 353 354config 64KB_3LEVEL 355 bool "64KB with 3 levels" 356 select HAVE_PAGE_SIZE_64KB 357 select PGTABLE_3LEVEL 358 help 359 This option selects 64KB page size with 3 level page tables, which 360 support a maximum of 55 bits of application virtual memory. 361 362endchoice 363 364config CMDLINE 365 string "Built-in kernel command line" 366 help 367 For most platforms, the arguments for the kernel's command line 368 are provided at run-time, during boot. However, there are cases 369 where either no arguments are being provided or the provided 370 arguments are insufficient or even invalid. 371 372 When that occurs, it is possible to define a built-in command 373 line here and choose how the kernel should use it later on. 374 375choice 376 prompt "Kernel command line type" 377 default CMDLINE_BOOTLOADER 378 help 379 Choose how the kernel will handle the provided built-in command 380 line. 381 382config CMDLINE_BOOTLOADER 383 bool "Use bootloader kernel arguments if available" 384 help 385 Prefer the command-line passed by the boot loader if available. 386 Use the built-in command line as fallback in case we get nothing 387 during boot. This is the default behaviour. 388 389config CMDLINE_EXTEND 390 bool "Use built-in to extend bootloader kernel arguments" 391 help 392 The built-in command line will be appended to the command- 393 line arguments provided during boot. This is useful in 394 cases where the provided arguments are insufficient and 395 you don't want to or cannot modify them. 396 397config CMDLINE_FORCE 398 bool "Always use the built-in kernel command string" 399 help 400 Always use the built-in command line, even if we get one during 401 boot. This is useful in case you need to override the provided 402 command line on systems where you don't have or want control 403 over it. 404 405endchoice 406 407config BUILTIN_DTB 408 bool "Enable built-in dtb in kernel" 409 depends on OF 410 select GENERIC_BUILTIN_DTB 411 help 412 Some existing systems do not provide a canonical device tree to 413 the kernel at boot time. Let's provide a device tree table in the 414 kernel, keyed by the dts filename, containing the relevant DTBs. 415 416 Built-in DTBs are generic enough and can be used as references. 417 418config BUILTIN_DTB_NAME 419 string "Source file for built-in dtb" 420 depends on BUILTIN_DTB 421 help 422 Base name (without suffix, relative to arch/loongarch/boot/dts/) 423 for the DTS file that will be used to produce the DTB linked into 424 the kernel. 425 426config DMI 427 bool "Enable DMI scanning" 428 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 429 default y 430 help 431 This enables SMBIOS/DMI feature for systems, and scanning of 432 DMI to identify machine quirks. 433 434config EFI 435 bool "EFI runtime service support" 436 select UCS2_STRING 437 select EFI_RUNTIME_WRAPPERS 438 help 439 This enables the kernel to use EFI runtime services that are 440 available (such as the EFI variable services). 441 442config EFI_STUB 443 bool "EFI boot stub support" 444 default y 445 depends on EFI 446 select EFI_GENERIC_STUB 447 help 448 This kernel feature allows the kernel to be loaded directly by 449 EFI firmware without the use of a bootloader. 450 451config SCHED_SMT 452 bool "SMT scheduler support" 453 depends on SMP 454 default y 455 help 456 Improves scheduler's performance when there are multiple 457 threads in one physical core. 458 459config SMP 460 bool "Multi-Processing support" 461 help 462 This enables support for systems with more than one CPU. If you have 463 a system with only one CPU, say N. If you have a system with more 464 than one CPU, say Y. 465 466 If you say N here, the kernel will run on uni- and multiprocessor 467 machines, but will use only one CPU of a multiprocessor machine. If 468 you say Y here, the kernel will run on many, but not all, 469 uniprocessor machines. On a uniprocessor machine, the kernel 470 will run faster if you say N here. 471 472 See also the SMP-HOWTO available at <http://www.tldp.org/docs.html#howto>. 473 474 If you don't know what to do here, say N. 475 476config HOTPLUG_CPU 477 bool "Support for hot-pluggable CPUs" 478 depends on SMP 479 select GENERIC_IRQ_MIGRATION 480 help 481 Say Y here to allow turning CPUs off and on. CPUs can be 482 controlled through /sys/devices/system/cpu. 483 (Note: power management support will enable this option 484 automatically on SMP systems. ) 485 Say N if you want to disable CPU hotplug. 486 487config NR_CPUS 488 int "Maximum number of CPUs (2-256)" 489 range 2 256 490 depends on SMP 491 default "64" 492 help 493 This allows you to specify the maximum number of CPUs which this 494 kernel will support. 495 496config NUMA 497 bool "NUMA Support" 498 select SMP 499 help 500 Say Y to compile the kernel with NUMA (Non-Uniform Memory Access) 501 support. This option improves performance on systems with more 502 than one NUMA node; on single node systems it is generally better 503 to leave it disabled. 504 505config NODES_SHIFT 506 int 507 default "6" 508 depends on NUMA 509 510config ARCH_FORCE_MAX_ORDER 511 int "Maximum zone order" 512 default "13" if PAGE_SIZE_64KB 513 default "11" if PAGE_SIZE_16KB 514 default "10" 515 help 516 The kernel memory allocator divides physically contiguous memory 517 blocks into "zones", where each zone is a power of two number of 518 pages. This option selects the largest power of two that the kernel 519 keeps in the memory allocator. If you need to allocate very large 520 blocks of physically contiguous memory, then you may need to 521 increase this value. 522 523 The page size is not necessarily 4KB. Keep this in mind 524 when choosing a value for this option. 525 526config ARCH_IOREMAP 527 bool "Enable LoongArch DMW-based ioremap()" 528 help 529 We use generic TLB-based ioremap() by default since it has page 530 protection support. However, you can enable LoongArch DMW-based 531 ioremap() for better performance. 532 533config ARCH_WRITECOMBINE 534 bool "Enable WriteCombine (WUC) for ioremap()" 535 help 536 LoongArch maintains cache coherency in hardware, but when paired 537 with LS7A chipsets the WUC attribute (Weak-ordered UnCached, which 538 is similar to WriteCombine) is out of the scope of cache coherency 539 machanism for PCIe devices (this is a PCIe protocol violation, which 540 may be fixed in newer chipsets). 541 542 This means WUC can only used for write-only memory regions now, so 543 this option is disabled by default, making WUC silently fallback to 544 SUC for ioremap(). You can enable this option if the kernel is ensured 545 to run on hardware without this bug. 546 547 You can override this setting via writecombine=on/off boot parameter. 548 549config ARCH_STRICT_ALIGN 550 bool "Enable -mstrict-align to prevent unaligned accesses" if EXPERT 551 default y 552 help 553 Not all LoongArch cores support h/w unaligned access, we can use 554 -mstrict-align build parameter to prevent unaligned accesses. 555 556 CPUs with h/w unaligned access support: 557 Loongson-2K2000/2K3000/3A5000/3C5000/3D5000. 558 559 CPUs without h/w unaligned access support: 560 Loongson-2K500/2K1000. 561 562 This option is enabled by default to make the kernel be able to run 563 on all LoongArch systems. But you can disable it manually if you want 564 to run kernel only on systems with h/w unaligned access support in 565 order to optimise for performance. 566 567config CPU_HAS_FPU 568 bool 569 default y 570 571config CPU_HAS_LSX 572 bool "Support for the Loongson SIMD Extension" 573 depends on AS_HAS_LSX_EXTENSION 574 help 575 Loongson SIMD Extension (LSX) introduces 128 bit wide vector registers 576 and a set of SIMD instructions to operate on them. When this option 577 is enabled the kernel will support allocating & switching LSX 578 vector register contexts. If you know that your kernel will only be 579 running on CPUs which do not support LSX or that your userland will 580 not be making use of it then you may wish to say N here to reduce 581 the size & complexity of your kernel. 582 583 If unsure, say Y. 584 585config CPU_HAS_LASX 586 bool "Support for the Loongson Advanced SIMD Extension" 587 depends on CPU_HAS_LSX 588 depends on AS_HAS_LASX_EXTENSION 589 help 590 Loongson Advanced SIMD Extension (LASX) introduces 256 bit wide vector 591 registers and a set of SIMD instructions to operate on them. When this 592 option is enabled the kernel will support allocating & switching LASX 593 vector register contexts. If you know that your kernel will only be 594 running on CPUs which do not support LASX or that your userland will 595 not be making use of it then you may wish to say N here to reduce 596 the size & complexity of your kernel. 597 598 If unsure, say Y. 599 600config CPU_HAS_LBT 601 bool "Support for the Loongson Binary Translation Extension" 602 depends on AS_HAS_LBT_EXTENSION 603 help 604 Loongson Binary Translation (LBT) introduces 4 scratch registers (SCR0 605 to SCR3), x86/ARM eflags (eflags) and x87 fpu stack pointer (ftop). 606 Enabling this option allows the kernel to allocate and switch registers 607 specific to LBT. 608 609 If you want to use this feature, such as the Loongson Architecture 610 Translator (LAT), say Y. 611 612config CPU_HAS_PREFETCH 613 bool 614 default y 615 616config ARCH_SUPPORTS_KEXEC 617 def_bool y 618 619config ARCH_SUPPORTS_CRASH_DUMP 620 def_bool y 621 622config ARCH_DEFAULT_CRASH_DUMP 623 def_bool y 624 625config ARCH_SELECTS_CRASH_DUMP 626 def_bool y 627 depends on CRASH_DUMP 628 select RELOCATABLE 629 630config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 631 def_bool CRASH_RESERVE 632 633config RELOCATABLE 634 bool "Relocatable kernel" 635 select ARCH_HAS_RELR 636 help 637 This builds the kernel as a Position Independent Executable (PIE), 638 which retains all relocation metadata required, so as to relocate 639 the kernel binary at runtime to a different virtual address from 640 its link address. 641 642config RANDOMIZE_BASE 643 bool "Randomize the address of the kernel (KASLR)" 644 depends on RELOCATABLE 645 help 646 Randomizes the physical and virtual address at which the 647 kernel image is loaded, as a security feature that 648 deters exploit attempts relying on knowledge of the location 649 of kernel internals. 650 651 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET. 652 653 If unsure, say N. 654 655config RANDOMIZE_BASE_MAX_OFFSET 656 hex "Maximum KASLR offset" if EXPERT 657 depends on RANDOMIZE_BASE 658 range 0x0 0x10000000 659 default "0x01000000" 660 help 661 When KASLR is active, this provides the maximum offset that will 662 be applied to the kernel image. It should be set according to the 663 amount of physical RAM available in the target system. 664 665 This is limited by the size of the lower address memory, 256MB. 666 667source "kernel/livepatch/Kconfig" 668 669config PARAVIRT 670 bool "Enable paravirtualization code" 671 depends on AS_HAS_LVZ_EXTENSION 672 help 673 This changes the kernel so it can modify itself when it is run 674 under a hypervisor, potentially improving performance significantly 675 over full virtualization. However, when run without a hypervisor 676 the kernel is theoretically slower and slightly larger. 677 678config PARAVIRT_TIME_ACCOUNTING 679 bool "Paravirtual steal time accounting" 680 depends on PARAVIRT 681 help 682 Select this option to enable fine granularity task steal time 683 accounting. Time spent executing other tasks in parallel with 684 the current vCPU is discounted from the vCPU power. To account for 685 that, there can be a small performance impact. 686 687 If in doubt, say N here. 688 689endmenu 690 691config ARCH_SELECT_MEMORY_MODEL 692 def_bool y 693 694config ARCH_FLATMEM_ENABLE 695 def_bool y 696 depends on !NUMA 697 698config ARCH_SPARSEMEM_ENABLE 699 def_bool y 700 select SPARSEMEM_VMEMMAP_ENABLE 701 help 702 Say Y to support efficient handling of sparse physical memory, 703 for architectures which are either NUMA (Non-Uniform Memory Access) 704 or have huge holes in the physical address space for other reasons. 705 See <file:Documentation/mm/numa.rst> for more. 706 707config ARCH_MEMORY_PROBE 708 def_bool y 709 depends on MEMORY_HOTPLUG 710 711config MMU 712 bool 713 default y 714 715config ARCH_MMAP_RND_BITS_MIN 716 default 12 717 718config ARCH_MMAP_RND_BITS_MAX 719 default 18 720 721config ARCH_SUPPORTS_UPROBES 722 def_bool y 723 724config KASAN_SHADOW_OFFSET 725 hex 726 default 0x0 727 depends on KASAN 728 729menu "Power management options" 730 731config ARCH_SUSPEND_POSSIBLE 732 def_bool y 733 734config ARCH_HIBERNATION_POSSIBLE 735 def_bool y 736 737source "kernel/power/Kconfig" 738source "drivers/acpi/Kconfig" 739source "drivers/cpufreq/Kconfig" 740 741endmenu 742 743source "arch/loongarch/kvm/Kconfig" 744