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