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