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