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