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