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