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