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