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_NEEDS_DEFER_KASAN 13 select ARCH_DISABLE_KASAN_INLINE 14 select ARCH_ENABLE_MEMORY_HOTPLUG 15 select ARCH_HAS_PMD_SOFTLEAVES 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 64BIT && 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_SPECIAL if 64BIT 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_HAS_UBSAN 32 select ARCH_HAS_VDSO_ARCH_DATA 33 select ARCH_INLINE_READ_LOCK if !PREEMPTION 34 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION 35 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION 36 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION 37 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION 38 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION 39 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION 40 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION 41 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION 42 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION 43 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION 44 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION 45 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION 46 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION 47 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION 48 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION 49 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION 50 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION 51 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION 52 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION 53 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION 54 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION 55 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION 56 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION 57 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION 58 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION 59 select ARCH_KEEP_MEMBLOCK 60 select ARCH_MIGHT_HAVE_PC_PARPORT 61 select ARCH_MIGHT_HAVE_PC_SERIO 62 select ARCH_STACKWALK 63 select ARCH_SUPPORTS_ACPI 64 select ARCH_SUPPORTS_ATOMIC_RMW 65 select ARCH_SUPPORTS_HUGETLBFS if 64BIT 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_MSEAL_SYSTEM_MAPPINGS 70 select ARCH_HAS_PTE_PROTNONE if 64BIT 71 select ARCH_SUPPORTS_NUMA_BALANCING if NUMA 72 select ARCH_SUPPORTS_PER_VMA_LOCK 73 select ARCH_SUPPORTS_RT 74 select ARCH_SUPPORTS_SCHED_SMT if SMP 75 select ARCH_SUPPORTS_SCHED_MC if SMP 76 select ARCH_USE_BUILTIN_BSWAP 77 select ARCH_USE_CMPXCHG_LOCKREF 78 select ARCH_USE_MEMTEST 79 select ARCH_USE_QUEUED_RWLOCKS 80 select ARCH_USE_QUEUED_SPINLOCKS 81 select ARCH_WANT_DEFAULT_BPF_JIT if HAVE_EBPF_JIT 82 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 83 select ARCH_WANT_LD_ORPHAN_WARN 84 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP if 64BIT 85 select ARCH_WANTS_NO_INSTR 86 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE 87 select BUILDTIME_TABLE_SORT 88 select COMMON_CLK 89 select CPU_PM 90 select EDAC_SUPPORT 91 select EFI 92 select GENERIC_ATOMIC64 if 32BIT 93 select GENERIC_CLOCKEVENTS 94 select GENERIC_CMOS_UPDATE 95 select GENERIC_CPU_AUTOPROBE 96 select GENERIC_CPU_DEVICES 97 select GENERIC_CPU_VULNERABILITIES 98 select GENERIC_ENTRY 99 select GENERIC_GETTIMEOFDAY if 64BIT 100 select GENERIC_IOREMAP if !ARCH_IOREMAP 101 select GENERIC_IRQ_MATRIX_ALLOCATOR 102 select GENERIC_IRQ_MULTI_HANDLER 103 select GENERIC_IRQ_PROBE 104 select GENERIC_IRQ_SHOW 105 select GENERIC_LIB_ASHLDI3 106 select GENERIC_LIB_ASHRDI3 107 select GENERIC_LIB_CMPDI2 108 select GENERIC_LIB_LSHRDI3 109 select GENERIC_LIB_UCMPDI2 110 select GENERIC_LIB_DEVMEM_IS_ALLOWED 111 select GENERIC_PCI_IOMAP 112 select GENERIC_SCHED_CLOCK 113 select GENERIC_SMP_IDLE_THREAD 114 select GPIOLIB 115 select HAS_IOPORT 116 select HAVE_ALIGNED_STRUCT_PAGE if 64BIT 117 select HAVE_ARCH_AUDITSYSCALL 118 select HAVE_ARCH_BITREVERSE if 64BIT && BITREVERSE 119 select HAVE_ARCH_JUMP_LABEL 120 select HAVE_ARCH_JUMP_LABEL_RELATIVE 121 select HAVE_ARCH_KASAN if 64BIT 122 select HAVE_ARCH_KFENCE if 64BIT 123 select HAVE_ARCH_KGDB if PERF_EVENTS 124 select HAVE_ARCH_KSTACK_ERASE 125 select HAVE_ARCH_MMAP_RND_BITS if MMU 126 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 127 select HAVE_ARCH_SECCOMP 128 select HAVE_ARCH_SECCOMP_FILTER 129 select HAVE_ARCH_TRACEHOOK 130 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT 131 select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD 132 select HAVE_ASM_MODVERSIONS 133 select HAVE_CMPXCHG_DOUBLE 134 select HAVE_CMPXCHG_LOCAL 135 select HAVE_CONTEXT_TRACKING_USER 136 select HAVE_C_RECORDMCOUNT 137 select HAVE_DEBUG_KMEMLEAK 138 select HAVE_DEBUG_STACKOVERFLOW 139 select HAVE_DMA_CONTIGUOUS 140 select HAVE_DYNAMIC_FTRACE 141 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 142 select HAVE_FTRACE_REGS_HAVING_PT_REGS 143 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 144 select HAVE_DYNAMIC_FTRACE_WITH_REGS 145 select HAVE_EBPF_JIT if 64BIT 146 select HAVE_EFFICIENT_UNALIGNED_ACCESS if !ARCH_STRICT_ALIGN 147 select HAVE_EXIT_THREAD 148 select HAVE_GENERIC_TIF_BITS 149 select HAVE_GUP_FAST 150 select HAVE_FTRACE_GRAPH_FUNC 151 select HAVE_FUNCTION_ARG_ACCESS_API 152 select HAVE_FUNCTION_ERROR_INJECTION 153 select HAVE_FUNCTION_GRAPH_FREGS 154 select HAVE_FUNCTION_GRAPH_TRACER 155 select HAVE_FUNCTION_TRACER 156 select HAVE_GCC_PLUGINS 157 select HAVE_HW_BREAKPOINT if PERF_EVENTS 158 select HAVE_IOREMAP_PROT 159 select HAVE_IRQ_EXIT_ON_IRQ_STACK 160 select HAVE_IRQ_TIME_ACCOUNTING 161 select HAVE_KPROBES 162 select HAVE_KPROBES_ON_FTRACE 163 select HAVE_KRETPROBES 164 select HAVE_LIVEPATCH 165 select HAVE_MOD_ARCH_SPECIFIC 166 select HAVE_NMI 167 select HAVE_OBJTOOL if AS_HAS_EXPLICIT_RELOCS && AS_HAS_THIN_ADD_SUB && 64BIT 168 select HAVE_PCI 169 select HAVE_PERF_EVENTS if 64BIT 170 select HAVE_PERF_REGS 171 select HAVE_PERF_USER_STACK_DUMP 172 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 173 select HAVE_PREEMPT_DYNAMIC_KEY 174 select HAVE_REGS_AND_STACK_ACCESS_API 175 select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC 176 select HAVE_RETHOOK 177 select HAVE_RSEQ 178 select HAVE_RUST 179 select HAVE_SAMPLE_FTRACE_DIRECT 180 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 181 select HAVE_SETUP_PER_CPU_AREA if NUMA 182 select HAVE_STACK_VALIDATION if HAVE_OBJTOOL 183 select HAVE_STACKPROTECTOR 184 select HAVE_SYSCALL_TRACEPOINTS 185 select HAVE_TIF_NOHZ 186 select HAVE_VIRT_CPU_ACCOUNTING_GEN 187 select HOTPLUG_SMT if HOTPLUG_CPU 188 select IRQ_FORCED_THREADING 189 select IRQ_LOONGARCH_CPU 190 select LOCK_MM_AND_FIND_VMA 191 select MMU_GATHER_MERGE_VMAS if MMU 192 select MMU_GATHER_RCU_TABLE_FREE 193 select MODULES_USE_ELF_RELA if MODULES 194 select NEED_PER_CPU_EMBED_FIRST_CHUNK 195 select NEED_PER_CPU_PAGE_FIRST_CHUNK 196 select NUMA_MEMBLKS if NUMA 197 select OF 198 select OF_EARLY_FLATTREE 199 select PCI 200 select PCI_DOMAINS_GENERIC 201 select PCI_ECAM if ACPI 202 select PCI_LOONGSON 203 select PCI_MSI_ARCH_FALLBACKS 204 select PCI_QUIRKS 205 select PERF_USE_VMALLOC 206 select RTC_LIB 207 select SPARSE_IRQ 208 select SYSCTL_ARCH_UNALIGN_ALLOW 209 select SYSCTL_ARCH_UNALIGN_NO_WARN 210 select SYSCTL_EXCEPTION_TRACE 211 select SWIOTLB if 64BIT 212 select THREAD_INFO_IN_TASK 213 select TRACE_IRQFLAGS_SUPPORT 214 select USE_PERCPU_NUMA_NODE_ID 215 select USER_STACKTRACE_SUPPORT 216 select VDSO_DATASTORE 217 select VDSO_GETRANDOM 218 select ZONE_DMA32 if 64BIT 219 220menu "Kernel type and options" 221 222choice 223 prompt "Kernel type" 224 default 64BIT # Keep existing behavior 225 226config 32BIT 227 bool "32-bit kernel" 228 help 229 Select this option if you want to build a 32-bit kernel. 230 231config 64BIT 232 bool "64-bit kernel" 233 help 234 Select this option if you want to build a 64-bit kernel. 235 236endchoice 237 238if 32BIT 239 240choice 241 prompt "32-bit kernel sub-type" 242 243config 32BIT_REDUCED 244 bool "32-bit kernel for LA32R" 245 help 246 Select this option if you want to build a 32-bit kernel for 247 LoongArch32 Reduced (LA32R). 248 249config 32BIT_STANDARD 250 bool "32-bit kernel for LA32S" 251 help 252 Select this option if you want to build a 32-bit kernel for 253 LoongArch32 Standard (LA32S). 254 255endchoice 256 257endif 258 259config GENERIC_BUG 260 def_bool y 261 depends on BUG 262 263config GENERIC_BUG_RELATIVE_POINTERS 264 def_bool y 265 depends on GENERIC_BUG 266 267config GENERIC_CALIBRATE_DELAY 268 def_bool y 269 270config GENERIC_CSUM 271 def_bool y 272 273config GENERIC_HWEIGHT 274 def_bool y 275 276config L1_CACHE_SHIFT 277 int 278 default "6" 279 280config LOCKDEP_SUPPORT 281 bool 282 default y 283 284config STACKTRACE_SUPPORT 285 bool 286 default y 287 288# MACH_LOONGSON32 and MACH_LOONGSON64 are deliberately carried over from the 289# MIPS Loongson code, to preserve Loongson-specific code paths in drivers that 290# are shared between architectures, and specifically expecting the symbols. 291config MACH_LOONGSON32 292 def_bool 32BIT 293 294config MACH_LOONGSON64 295 def_bool 64BIT 296 297config FIX_EARLYCON_MEM 298 def_bool !ARCH_IOREMAP 299 300config PGTABLE_2LEVEL 301 bool 302 303config PGTABLE_3LEVEL 304 bool 305 306config PGTABLE_4LEVEL 307 bool 308 309config PGTABLE_LEVELS 310 int 311 default 2 if PGTABLE_2LEVEL 312 default 3 if PGTABLE_3LEVEL 313 default 4 if PGTABLE_4LEVEL 314 315config SCHED_OMIT_FRAME_POINTER 316 bool 317 default y 318 319config AS_HAS_EXPLICIT_RELOCS 320 def_bool $(as-instr,x:pcalau12i \$t0$(comma)%pc_hi20(x)) 321 322config AS_HAS_FCSR_CLASS 323 def_bool $(as-instr,movfcsr2gr \$t0$(comma)\$fcsr0) 324 325config AS_HAS_THIN_ADD_SUB 326 def_bool $(cc-option,-Wa$(comma)-mthin-add-sub) || AS_IS_LLVM 327 328config AS_HAS_LSX_EXTENSION 329 def_bool $(as-instr,vld \$vr0$(comma)\$a0$(comma)0) 330 331config AS_HAS_LASX_EXTENSION 332 def_bool $(as-instr,xvld \$xr0$(comma)\$a0$(comma)0) 333 334config AS_HAS_LBT_EXTENSION 335 def_bool $(as-instr,movscr2gr \$a0$(comma)\$scr0) 336 337config AS_HAS_LVZ_EXTENSION 338 def_bool $(as-instr,hvcl 0) 339 340config AS_HAS_SCQ_EXTENSION 341 def_bool $(as-instr,sc.q \$t0$(comma)\$t1$(comma)\$t2) 342 343config CC_HAS_ANNOTATE_TABLEJUMP 344 def_bool $(cc-option,-mannotate-tablejump) 345 346config RUSTC_HAS_ANNOTATE_TABLEJUMP 347 depends on RUST 348 def_bool $(rustc-option,-Cllvm-args=--loongarch-annotate-tablejump) 349 350source "kernel/Kconfig.hz" 351 352config HIGHMEM 353 bool "High Memory Support" 354 depends on 32BIT 355 select KMAP_LOCAL 356 357choice 358 prompt "Page Table Layout" 359 default 16KB_2LEVEL if 32BIT 360 default 16KB_3LEVEL if 64BIT 361 help 362 Allows choosing the page table layout, which is a combination 363 of page size and page table levels. The size of virtual memory 364 address space are determined by the page table layout. 365 366config 4KB_2LEVEL 367 bool "4KB with 2 levels" 368 select HAVE_PAGE_SIZE_4KB 369 select PGTABLE_2LEVEL 370 help 371 This option selects 4KB page size with 2 level page tables, which 372 support a maximum of 32 bits of application virtual memory. 373 374config 4KB_3LEVEL 375 bool "4KB with 3 levels" 376 depends on 64BIT 377 select HAVE_PAGE_SIZE_4KB 378 select PGTABLE_3LEVEL 379 help 380 This option selects 4KB page size with 3 level page tables, which 381 support a maximum of 39 bits of application virtual memory. 382 383config 4KB_4LEVEL 384 bool "4KB with 4 levels" 385 depends on 64BIT 386 select HAVE_PAGE_SIZE_4KB 387 select PGTABLE_4LEVEL 388 help 389 This option selects 4KB page size with 4 level page tables, which 390 support a maximum of 48 bits of application virtual memory. 391 392config 16KB_2LEVEL 393 bool "16KB with 2 levels" 394 select HAVE_PAGE_SIZE_16KB 395 select PGTABLE_2LEVEL 396 help 397 This option selects 16KB page size with 2 level page tables, which 398 support a maximum of 36 bits of application virtual memory. 399 400config 16KB_3LEVEL 401 bool "16KB with 3 levels" 402 depends on 64BIT 403 select HAVE_PAGE_SIZE_16KB 404 select PGTABLE_3LEVEL 405 help 406 This option selects 16KB page size with 3 level page tables, which 407 support a maximum of 47 bits of application virtual memory. 408 409config 64KB_2LEVEL 410 bool "64KB with 2 levels" 411 select HAVE_PAGE_SIZE_64KB 412 select PGTABLE_2LEVEL 413 help 414 This option selects 64KB page size with 2 level page tables, which 415 support a maximum of 42 bits of application virtual memory. 416 417config 64KB_3LEVEL 418 bool "64KB with 3 levels" 419 depends on 64BIT 420 select HAVE_PAGE_SIZE_64KB 421 select PGTABLE_3LEVEL 422 help 423 This option selects 64KB page size with 3 level page tables, which 424 support a maximum of 55 bits of application virtual memory. 425 426endchoice 427 428config CMDLINE 429 string "Built-in kernel command line" 430 help 431 For most platforms, the arguments for the kernel's command line 432 are provided at run-time, during boot. However, there are cases 433 where either no arguments are being provided or the provided 434 arguments are insufficient or even invalid. 435 436 When that occurs, it is possible to define a built-in command 437 line here and choose how the kernel should use it later on. 438 439choice 440 prompt "Kernel command line type" 441 default CMDLINE_BOOTLOADER 442 help 443 Choose how the kernel will handle the provided built-in command 444 line. 445 446config CMDLINE_BOOTLOADER 447 bool "Use bootloader kernel arguments if available" 448 help 449 Prefer the command-line passed by the boot loader if available. 450 Use the built-in command line as fallback in case we get nothing 451 during boot. This is the default behaviour. 452 453config CMDLINE_EXTEND 454 bool "Use built-in to extend bootloader kernel arguments" 455 help 456 The built-in command line will be appended to the command- 457 line arguments provided during boot. This is useful in 458 cases where the provided arguments are insufficient and 459 you don't want to or cannot modify them. 460 461config CMDLINE_FORCE 462 bool "Always use the built-in kernel command string" 463 help 464 Always use the built-in command line, even if we get one during 465 boot. This is useful in case you need to override the provided 466 command line on systems where you don't have or want control 467 over it. 468 469endchoice 470 471config BUILTIN_DTB 472 bool "Enable built-in dtb in kernel" 473 depends on OF 474 select GENERIC_BUILTIN_DTB 475 help 476 Some existing systems do not provide a canonical device tree to 477 the kernel at boot time. Let's provide a device tree table in the 478 kernel, keyed by the dts filename, containing the relevant DTBs. 479 480 Built-in DTBs are generic enough and can be used as references. 481 482config BUILTIN_DTB_NAME 483 string "Source file for built-in dtb" 484 depends on BUILTIN_DTB 485 help 486 Base name (without suffix, relative to arch/loongarch/boot/dts/) 487 for the DTS file that will be used to produce the DTB linked into 488 the kernel. 489 490config DMI 491 bool "Enable DMI scanning" 492 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 493 default y 494 help 495 This enables SMBIOS/DMI feature for systems, and scanning of 496 DMI to identify machine quirks. 497 498config EFI 499 bool "EFI runtime service support" 500 select UCS2_STRING 501 select EFI_RUNTIME_WRAPPERS 502 help 503 This enables the kernel to use EFI runtime services that are 504 available (such as the EFI variable services). 505 506config EFI_STUB 507 bool "EFI boot stub support" 508 default y 509 depends on EFI 510 select EFI_GENERIC_STUB 511 help 512 This kernel feature allows the kernel to be loaded directly by 513 EFI firmware without the use of a bootloader. 514 515config SMP 516 bool "Multi-Processing support" 517 depends on 64BIT 518 help 519 This enables support for systems with more than one CPU. If you have 520 a system with only one CPU, say N. If you have a system with more 521 than one CPU, say Y. 522 523 If you say N here, the kernel will run on uni- and multiprocessor 524 machines, but will use only one CPU of a multiprocessor machine. If 525 you say Y here, the kernel will run on many, but not all, 526 uniprocessor machines. On a uniprocessor machine, the kernel 527 will run faster if you say N here. 528 529 See also the SMP-HOWTO available at <http://www.tldp.org/docs.html#howto>. 530 531 If you don't know what to do here, say N. 532 533config HOTPLUG_CPU 534 bool "Support for hot-pluggable CPUs" 535 depends on SMP 536 select GENERIC_IRQ_MIGRATION 537 help 538 Say Y here to allow turning CPUs off and on. CPUs can be 539 controlled through /sys/devices/system/cpu. 540 (Note: power management support will enable this option 541 automatically on SMP systems. ) 542 Say N if you want to disable CPU hotplug. 543 544config NR_CPUS 545 int "Maximum number of CPUs (2-2048)" 546 range 2 2048 547 default "2048" 548 depends on SMP 549 help 550 This allows you to specify the maximum number of CPUs which this 551 kernel will support. 552 553config NUMA 554 bool "NUMA Support" 555 select SMP 556 depends on 64BIT 557 help 558 Say Y to compile the kernel with NUMA (Non-Uniform Memory Access) 559 support. This option improves performance on systems with more 560 than one NUMA node; on single node systems it is generally better 561 to leave it disabled. 562 563config NODES_SHIFT 564 int 565 default "6" 566 depends on NUMA 567 568config ARCH_FORCE_MAX_ORDER 569 int "Maximum zone order" 570 default "13" if PAGE_SIZE_64KB 571 default "11" if PAGE_SIZE_16KB 572 default "10" 573 help 574 The kernel memory allocator divides physically contiguous memory 575 blocks into "zones", where each zone is a power of two number of 576 pages. This option selects the largest power of two that the kernel 577 keeps in the memory allocator. If you need to allocate very large 578 blocks of physically contiguous memory, then you may need to 579 increase this value. 580 581 The page size is not necessarily 4KB. Keep this in mind 582 when choosing a value for this option. 583 584config ARCH_IOREMAP 585 bool "Enable LoongArch DMW-based ioremap()" 586 help 587 We use generic TLB-based ioremap() by default since it has page 588 protection support. However, you can enable LoongArch DMW-based 589 ioremap() for better performance. 590 591config ARCH_WRITECOMBINE 592 bool "Enable WriteCombine (WUC) for ioremap()" 593 help 594 LoongArch maintains cache coherency in hardware, but when paired 595 with LS7A chipsets the WUC attribute (Weak-ordered UnCached, which 596 is similar to WriteCombine) is out of the scope of cache coherency 597 machanism for PCIe devices (this is a PCIe protocol violation, which 598 may be fixed in newer chipsets). 599 600 This means WUC can only used for write-only memory regions now, so 601 this option is disabled by default, making WUC silently fallback to 602 SUC for ioremap(). You can enable this option if the kernel is ensured 603 to run on hardware without this bug. 604 605 You can override this setting via writecombine=on/off boot parameter. 606 607config ARCH_STRICT_ALIGN 608 bool "Enable -mstrict-align to prevent unaligned accesses" if EXPERT 609 default y 610 help 611 Not all LoongArch cores support h/w unaligned access, we can use 612 -mstrict-align build parameter to prevent unaligned accesses. 613 614 CPUs with h/w unaligned access support: 615 Loongson-2K2000/2K3000 and all of Loongson-3 series processors 616 based on LoongArch. 617 618 CPUs without h/w unaligned access support: 619 Loongson-2K0300/2K0500/2K1000. 620 621 If you want to make sure whether to support unaligned memory access 622 on your hardware, please read the bit 20 (UAL) of CPUCFG1 register. 623 624 This option is enabled by default to make the kernel be able to run 625 on all LoongArch systems. But you can disable it manually if you want 626 to run kernel only on systems with h/w unaligned access support in 627 order to optimise for performance. 628 629config CPU_HAS_AMO 630 bool 631 default 64BIT 632 633config CPU_HAS_FPU 634 bool 635 default y 636 637config CPU_HAS_LSX 638 bool "Support for the Loongson SIMD Extension" 639 depends on AS_HAS_LSX_EXTENSION && 64BIT 640 help 641 Loongson SIMD Extension (LSX) introduces 128 bit wide vector registers 642 and a set of SIMD instructions to operate on them. When this option 643 is enabled the kernel will support allocating & switching LSX 644 vector register contexts. If you know that your kernel will only be 645 running on CPUs which do not support LSX or that your userland will 646 not be making use of it then you may wish to say N here to reduce 647 the size & complexity of your kernel. 648 649 If unsure, say Y. 650 651config CPU_HAS_LASX 652 bool "Support for the Loongson Advanced SIMD Extension" 653 depends on CPU_HAS_LSX 654 depends on AS_HAS_LASX_EXTENSION && 64BIT 655 help 656 Loongson Advanced SIMD Extension (LASX) introduces 256 bit wide vector 657 registers and a set of SIMD instructions to operate on them. When this 658 option is enabled the kernel will support allocating & switching LASX 659 vector register contexts. If you know that your kernel will only be 660 running on CPUs which do not support LASX or that your userland will 661 not be making use of it then you may wish to say N here to reduce 662 the size & complexity of your kernel. 663 664 If unsure, say Y. 665 666config CPU_HAS_LBT 667 bool "Support for the Loongson Binary Translation Extension" 668 depends on AS_HAS_LBT_EXTENSION && 64BIT 669 help 670 Loongson Binary Translation (LBT) introduces 4 scratch registers (SCR0 671 to SCR3), x86/ARM eflags (eflags) and x87 fpu stack pointer (ftop). 672 Enabling this option allows the kernel to allocate and switch registers 673 specific to LBT. 674 675 If you want to use this feature, such as the Loongson Architecture 676 Translator (LAT), say Y. 677 678config CPU_HAS_PREFETCH 679 bool 680 default y 681 682config ARCH_SUPPORTS_KEXEC 683 def_bool y 684 685config ARCH_SUPPORTS_KEXEC_FILE 686 def_bool 64BIT 687 688config ARCH_SELECTS_KEXEC_FILE 689 def_bool 64BIT 690 depends on KEXEC_FILE 691 select KEXEC_ELF 692 select RELOCATABLE 693 select HAVE_IMA_KEXEC if IMA 694 695config ARCH_SUPPORTS_CRASH_DUMP 696 def_bool 64BIT 697 698config ARCH_DEFAULT_CRASH_DUMP 699 def_bool 64BIT 700 701config ARCH_SELECTS_CRASH_DUMP 702 def_bool 64BIT 703 depends on CRASH_DUMP 704 select RELOCATABLE 705 706config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 707 def_bool CRASH_RESERVE 708 709config RELOCATABLE 710 bool "Relocatable kernel" 711 depends on 64BIT 712 select ARCH_HAS_RELR 713 help 714 This builds the kernel as a Position Independent Executable (PIE), 715 which retains all relocation metadata required, so as to relocate 716 the kernel binary at runtime to a different virtual address from 717 its link address. 718 719config RANDOMIZE_BASE 720 bool "Randomize the address of the kernel (KASLR)" 721 depends on RELOCATABLE 722 help 723 Randomizes the physical and virtual address at which the 724 kernel image is loaded, as a security feature that 725 deters exploit attempts relying on knowledge of the location 726 of kernel internals. 727 728 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET. 729 730 If unsure, say N. 731 732config RANDOMIZE_BASE_MAX_OFFSET 733 hex "Maximum KASLR offset" if EXPERT 734 depends on RANDOMIZE_BASE 735 range 0x0 0x10000000 736 default "0x01000000" 737 help 738 When KASLR is active, this provides the maximum offset that will 739 be applied to the kernel image. It should be set according to the 740 amount of physical RAM available in the target system. 741 742 This is limited by the size of the lower address memory, 256MB. 743 744source "kernel/livepatch/Kconfig" 745 746config PARAVIRT 747 bool "Enable paravirtualization code" 748 depends on AS_HAS_LVZ_EXTENSION && 64BIT 749 select HAVE_PV_STEAL_CLOCK_GEN 750 help 751 This changes the kernel so it can modify itself when it is run 752 under a hypervisor, potentially improving performance significantly 753 over full virtualization. However, when run without a hypervisor 754 the kernel is theoretically slower and slightly larger. 755 756config PARAVIRT_TIME_ACCOUNTING 757 bool "Paravirtual steal time accounting" 758 depends on PARAVIRT 759 help 760 Select this option to enable fine granularity task steal time 761 accounting. Time spent executing other tasks in parallel with 762 the current vCPU is discounted from the vCPU power. To account for 763 that, there can be a small performance impact. 764 765 If in doubt, say N here. 766 767endmenu 768 769config ARCH_SELECT_MEMORY_MODEL 770 def_bool y 771 772config ARCH_FLATMEM_ENABLE 773 def_bool y 774 depends on !NUMA 775 776config ARCH_SPARSEMEM_ENABLE 777 def_bool 64BIT 778 select SPARSEMEM_VMEMMAP_ENABLE 779 help 780 Say Y to support efficient handling of sparse physical memory, 781 for architectures which are either NUMA (Non-Uniform Memory Access) 782 or have huge holes in the physical address space for other reasons. 783 See <file:Documentation/mm/numa.rst> for more. 784 785config ARCH_MEMORY_PROBE 786 def_bool y 787 depends on MEMORY_HOTPLUG 788 789config MMU 790 bool 791 default y 792 793config ARCH_MMAP_RND_BITS_MIN 794 default 10 if 32BIT 795 default 12 if 64BIT 796 797config ARCH_MMAP_RND_BITS_MAX 798 default 15 if 32BIT 799 default 20 if 64BIT 800 801config ARCH_SUPPORTS_UPROBES 802 def_bool y 803 804config KASAN_SHADOW_OFFSET 805 hex 806 default 0x0 807 depends on KASAN 808 809menu "Power management options" 810 811config ARCH_SUSPEND_POSSIBLE 812 def_bool y 813 814config ARCH_HIBERNATION_POSSIBLE 815 def_bool y 816 817source "kernel/power/Kconfig" 818source "drivers/acpi/Kconfig" 819source "drivers/cpufreq/Kconfig" 820 821endmenu 822 823source "arch/loongarch/kvm/Kconfig" 824