1comment "Processor Type" 2 3# Select CPU types depending on the architecture selected. This selects 4# which CPUs we support in the kernel image, and the compiler instruction 5# optimiser behaviour. 6 7# ARM610 8config CPU_ARM610 9 bool "Support ARM610 processor" if ARCH_RPC 10 select CPU_32v3 11 select CPU_CACHE_V3 12 select CPU_CACHE_VIVT 13 select CPU_CP15_MMU 14 select CPU_COPY_V3 if MMU 15 select CPU_TLB_V3 if MMU 16 select CPU_PABRT_LEGACY 17 help 18 The ARM610 is the successor to the ARM3 processor 19 and was produced by VLSI Technology Inc. 20 21 Say Y if you want support for the ARM610 processor. 22 Otherwise, say N. 23 24# ARM7TDMI 25config CPU_ARM7TDMI 26 bool "Support ARM7TDMI processor" 27 depends on !MMU 28 select CPU_32v4T 29 select CPU_ABRT_LV4T 30 select CPU_PABRT_LEGACY 31 select CPU_CACHE_V4 32 help 33 A 32-bit RISC microprocessor based on the ARM7 processor core 34 which has no memory control unit and cache. 35 36 Say Y if you want support for the ARM7TDMI processor. 37 Otherwise, say N. 38 39# ARM710 40config CPU_ARM710 41 bool "Support ARM710 processor" if ARCH_RPC 42 select CPU_32v3 43 select CPU_CACHE_V3 44 select CPU_CACHE_VIVT 45 select CPU_CP15_MMU 46 select CPU_COPY_V3 if MMU 47 select CPU_TLB_V3 if MMU 48 select CPU_PABRT_LEGACY 49 help 50 A 32-bit RISC microprocessor based on the ARM7 processor core 51 designed by Advanced RISC Machines Ltd. The ARM710 is the 52 successor to the ARM610 processor. It was released in 53 July 1994 by VLSI Technology Inc. 54 55 Say Y if you want support for the ARM710 processor. 56 Otherwise, say N. 57 58# ARM720T 59config CPU_ARM720T 60 bool "Support ARM720T processor" if ARCH_INTEGRATOR 61 select CPU_32v4T 62 select CPU_ABRT_LV4T 63 select CPU_PABRT_LEGACY 64 select CPU_CACHE_V4 65 select CPU_CACHE_VIVT 66 select CPU_CP15_MMU 67 select CPU_COPY_V4WT if MMU 68 select CPU_TLB_V4WT if MMU 69 help 70 A 32-bit RISC processor with 8kByte Cache, Write Buffer and 71 MMU built around an ARM7TDMI core. 72 73 Say Y if you want support for the ARM720T processor. 74 Otherwise, say N. 75 76# ARM740T 77config CPU_ARM740T 78 bool "Support ARM740T processor" if ARCH_INTEGRATOR 79 depends on !MMU 80 select CPU_32v4T 81 select CPU_ABRT_LV4T 82 select CPU_PABRT_LEGACY 83 select CPU_CACHE_V3 # although the core is v4t 84 select CPU_CP15_MPU 85 help 86 A 32-bit RISC processor with 8KB cache or 4KB variants, 87 write buffer and MPU(Protection Unit) built around 88 an ARM7TDMI core. 89 90 Say Y if you want support for the ARM740T processor. 91 Otherwise, say N. 92 93# ARM9TDMI 94config CPU_ARM9TDMI 95 bool "Support ARM9TDMI processor" 96 depends on !MMU 97 select CPU_32v4T 98 select CPU_ABRT_NOMMU 99 select CPU_PABRT_LEGACY 100 select CPU_CACHE_V4 101 help 102 A 32-bit RISC microprocessor based on the ARM9 processor core 103 which has no memory control unit and cache. 104 105 Say Y if you want support for the ARM9TDMI processor. 106 Otherwise, say N. 107 108# ARM920T 109config CPU_ARM920T 110 bool "Support ARM920T processor" if ARCH_INTEGRATOR 111 select CPU_32v4T 112 select CPU_ABRT_EV4T 113 select CPU_PABRT_LEGACY 114 select CPU_CACHE_V4WT 115 select CPU_CACHE_VIVT 116 select CPU_CP15_MMU 117 select CPU_COPY_V4WB if MMU 118 select CPU_TLB_V4WBI if MMU 119 help 120 The ARM920T is licensed to be produced by numerous vendors, 121 and is used in the Cirrus EP93xx and the Samsung S3C2410. 122 123 Say Y if you want support for the ARM920T processor. 124 Otherwise, say N. 125 126# ARM922T 127config CPU_ARM922T 128 bool "Support ARM922T processor" if ARCH_INTEGRATOR 129 select CPU_32v4T 130 select CPU_ABRT_EV4T 131 select CPU_PABRT_LEGACY 132 select CPU_CACHE_V4WT 133 select CPU_CACHE_VIVT 134 select CPU_CP15_MMU 135 select CPU_COPY_V4WB if MMU 136 select CPU_TLB_V4WBI if MMU 137 help 138 The ARM922T is a version of the ARM920T, but with smaller 139 instruction and data caches. It is used in Altera's 140 Excalibur XA device family and Micrel's KS8695 Centaur. 141 142 Say Y if you want support for the ARM922T processor. 143 Otherwise, say N. 144 145# ARM925T 146config CPU_ARM925T 147 bool "Support ARM925T processor" if ARCH_OMAP1 148 select CPU_32v4T 149 select CPU_ABRT_EV4T 150 select CPU_PABRT_LEGACY 151 select CPU_CACHE_V4WT 152 select CPU_CACHE_VIVT 153 select CPU_CP15_MMU 154 select CPU_COPY_V4WB if MMU 155 select CPU_TLB_V4WBI if MMU 156 help 157 The ARM925T is a mix between the ARM920T and ARM926T, but with 158 different instruction and data caches. It is used in TI's OMAP 159 device family. 160 161 Say Y if you want support for the ARM925T processor. 162 Otherwise, say N. 163 164# ARM926T 165config CPU_ARM926T 166 bool "Support ARM926T processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB 167 select CPU_32v5 168 select CPU_ABRT_EV5TJ 169 select CPU_PABRT_LEGACY 170 select CPU_CACHE_VIVT 171 select CPU_CP15_MMU 172 select CPU_COPY_V4WB if MMU 173 select CPU_TLB_V4WBI if MMU 174 help 175 This is a variant of the ARM920. It has slightly different 176 instruction sequences for cache and TLB operations. Curiously, 177 there is no documentation on it at the ARM corporate website. 178 179 Say Y if you want support for the ARM926T processor. 180 Otherwise, say N. 181 182# FA526 183config CPU_FA526 184 bool 185 select CPU_32v4 186 select CPU_ABRT_EV4 187 select CPU_PABRT_LEGACY 188 select CPU_CACHE_VIVT 189 select CPU_CP15_MMU 190 select CPU_CACHE_FA 191 select CPU_COPY_FA if MMU 192 select CPU_TLB_FA if MMU 193 help 194 The FA526 is a version of the ARMv4 compatible processor with 195 Branch Target Buffer, Unified TLB and cache line size 16. 196 197 Say Y if you want support for the FA526 processor. 198 Otherwise, say N. 199 200# ARM940T 201config CPU_ARM940T 202 bool "Support ARM940T processor" if ARCH_INTEGRATOR 203 depends on !MMU 204 select CPU_32v4T 205 select CPU_ABRT_NOMMU 206 select CPU_PABRT_LEGACY 207 select CPU_CACHE_VIVT 208 select CPU_CP15_MPU 209 help 210 ARM940T is a member of the ARM9TDMI family of general- 211 purpose microprocessors with MPU and separate 4KB 212 instruction and 4KB data cases, each with a 4-word line 213 length. 214 215 Say Y if you want support for the ARM940T processor. 216 Otherwise, say N. 217 218# ARM946E-S 219config CPU_ARM946E 220 bool "Support ARM946E-S processor" if ARCH_INTEGRATOR 221 depends on !MMU 222 select CPU_32v5 223 select CPU_ABRT_NOMMU 224 select CPU_PABRT_LEGACY 225 select CPU_CACHE_VIVT 226 select CPU_CP15_MPU 227 help 228 ARM946E-S is a member of the ARM9E-S family of high- 229 performance, 32-bit system-on-chip processor solutions. 230 The TCM and ARMv5TE 32-bit instruction set is supported. 231 232 Say Y if you want support for the ARM946E-S processor. 233 Otherwise, say N. 234 235# ARM1020 - needs validating 236config CPU_ARM1020 237 bool "Support ARM1020T (rev 0) processor" if ARCH_INTEGRATOR 238 select CPU_32v5 239 select CPU_ABRT_EV4T 240 select CPU_PABRT_LEGACY 241 select CPU_CACHE_V4WT 242 select CPU_CACHE_VIVT 243 select CPU_CP15_MMU 244 select CPU_COPY_V4WB if MMU 245 select CPU_TLB_V4WBI if MMU 246 help 247 The ARM1020 is the 32K cached version of the ARM10 processor, 248 with an addition of a floating-point unit. 249 250 Say Y if you want support for the ARM1020 processor. 251 Otherwise, say N. 252 253# ARM1020E - needs validating 254config CPU_ARM1020E 255 bool "Support ARM1020E processor" if ARCH_INTEGRATOR 256 select CPU_32v5 257 select CPU_ABRT_EV4T 258 select CPU_PABRT_LEGACY 259 select CPU_CACHE_V4WT 260 select CPU_CACHE_VIVT 261 select CPU_CP15_MMU 262 select CPU_COPY_V4WB if MMU 263 select CPU_TLB_V4WBI if MMU 264 depends on n 265 266# ARM1022E 267config CPU_ARM1022 268 bool "Support ARM1022E processor" if ARCH_INTEGRATOR 269 select CPU_32v5 270 select CPU_ABRT_EV4T 271 select CPU_PABRT_LEGACY 272 select CPU_CACHE_VIVT 273 select CPU_CP15_MMU 274 select CPU_COPY_V4WB if MMU # can probably do better 275 select CPU_TLB_V4WBI if MMU 276 help 277 The ARM1022E is an implementation of the ARMv5TE architecture 278 based upon the ARM10 integer core with a 16KiB L1 Harvard cache, 279 embedded trace macrocell, and a floating-point unit. 280 281 Say Y if you want support for the ARM1022E processor. 282 Otherwise, say N. 283 284# ARM1026EJ-S 285config CPU_ARM1026 286 bool "Support ARM1026EJ-S processor" if ARCH_INTEGRATOR 287 select CPU_32v5 288 select CPU_ABRT_EV5T # But need Jazelle, but EV5TJ ignores bit 10 289 select CPU_PABRT_LEGACY 290 select CPU_CACHE_VIVT 291 select CPU_CP15_MMU 292 select CPU_COPY_V4WB if MMU # can probably do better 293 select CPU_TLB_V4WBI if MMU 294 help 295 The ARM1026EJ-S is an implementation of the ARMv5TEJ architecture 296 based upon the ARM10 integer core. 297 298 Say Y if you want support for the ARM1026EJ-S processor. 299 Otherwise, say N. 300 301# SA110 302config CPU_SA110 303 bool "Support StrongARM(R) SA-110 processor" if ARCH_RPC 304 select CPU_32v3 if ARCH_RPC 305 select CPU_32v4 if !ARCH_RPC 306 select CPU_ABRT_EV4 307 select CPU_PABRT_LEGACY 308 select CPU_CACHE_V4WB 309 select CPU_CACHE_VIVT 310 select CPU_CP15_MMU 311 select CPU_COPY_V4WB if MMU 312 select CPU_TLB_V4WB if MMU 313 help 314 The Intel StrongARM(R) SA-110 is a 32-bit microprocessor and 315 is available at five speeds ranging from 100 MHz to 233 MHz. 316 More information is available at 317 <http://developer.intel.com/design/strong/sa110.htm>. 318 319 Say Y if you want support for the SA-110 processor. 320 Otherwise, say N. 321 322# SA1100 323config CPU_SA1100 324 bool 325 select CPU_32v4 326 select CPU_ABRT_EV4 327 select CPU_PABRT_LEGACY 328 select CPU_CACHE_V4WB 329 select CPU_CACHE_VIVT 330 select CPU_CP15_MMU 331 select CPU_TLB_V4WB if MMU 332 333# XScale 334config CPU_XSCALE 335 bool 336 select CPU_32v5 337 select CPU_ABRT_EV5T 338 select CPU_PABRT_LEGACY 339 select CPU_CACHE_VIVT 340 select CPU_CP15_MMU 341 select CPU_TLB_V4WBI if MMU 342 343# XScale Core Version 3 344config CPU_XSC3 345 bool 346 select CPU_32v5 347 select CPU_ABRT_EV5T 348 select CPU_PABRT_LEGACY 349 select CPU_CACHE_VIVT 350 select CPU_CP15_MMU 351 select CPU_TLB_V4WBI if MMU 352 select IO_36 353 354# Marvell PJ1 (Mohawk) 355config CPU_MOHAWK 356 bool 357 select CPU_32v5 358 select CPU_ABRT_EV5T 359 select CPU_PABRT_LEGACY 360 select CPU_CACHE_VIVT 361 select CPU_CP15_MMU 362 select CPU_TLB_V4WBI if MMU 363 select CPU_COPY_V4WB if MMU 364 365# Feroceon 366config CPU_FEROCEON 367 bool 368 select CPU_32v5 369 select CPU_ABRT_EV5T 370 select CPU_PABRT_LEGACY 371 select CPU_CACHE_VIVT 372 select CPU_CP15_MMU 373 select CPU_COPY_FEROCEON if MMU 374 select CPU_TLB_FEROCEON if MMU 375 376config CPU_FEROCEON_OLD_ID 377 bool "Accept early Feroceon cores with an ARM926 ID" 378 depends on CPU_FEROCEON && !CPU_ARM926T 379 default y 380 help 381 This enables the usage of some old Feroceon cores 382 for which the CPU ID is equal to the ARM926 ID. 383 Relevant for Feroceon-1850 and early Feroceon-2850. 384 385# Marvell PJ4 386config CPU_PJ4 387 bool 388 select CPU_V7 389 select ARM_THUMBEE 390 391# ARMv6 392config CPU_V6 393 bool "Support ARM V6 processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB || MACH_REALVIEW_PBX 394 select CPU_32v6 395 select CPU_ABRT_EV6 396 select CPU_PABRT_V6 397 select CPU_CACHE_V6 398 select CPU_CACHE_VIPT 399 select CPU_CP15_MMU 400 select CPU_HAS_ASID if MMU 401 select CPU_COPY_V6 if MMU 402 select CPU_TLB_V6 if MMU 403 404# ARMv6k 405config CPU_V6K 406 bool "Support ARM V6K processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB || MACH_REALVIEW_PBX 407 select CPU_32v6 408 select CPU_32v6K 409 select CPU_ABRT_EV6 410 select CPU_PABRT_V6 411 select CPU_CACHE_V6 412 select CPU_CACHE_VIPT 413 select CPU_CP15_MMU 414 select CPU_HAS_ASID if MMU 415 select CPU_COPY_V6 if MMU 416 select CPU_TLB_V6 if MMU 417 418# ARMv7 419config CPU_V7 420 bool "Support ARM V7 processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB || MACH_REALVIEW_PBX 421 select CPU_32v6K 422 select CPU_32v7 423 select CPU_ABRT_EV7 424 select CPU_PABRT_V7 425 select CPU_CACHE_V7 426 select CPU_CACHE_VIPT 427 select CPU_CP15_MMU 428 select CPU_HAS_ASID if MMU 429 select CPU_COPY_V6 if MMU 430 select CPU_TLB_V7 if MMU 431 432# Figure out what processor architecture version we should be using. 433# This defines the compiler instruction set which depends on the machine type. 434config CPU_32v3 435 bool 436 select TLS_REG_EMUL if SMP || !MMU 437 select NEEDS_SYSCALL_FOR_CMPXCHG if SMP 438 select CPU_USE_DOMAINS if MMU 439 select NEED_KUSER_HELPERS 440 441config CPU_32v4 442 bool 443 select TLS_REG_EMUL if SMP || !MMU 444 select NEEDS_SYSCALL_FOR_CMPXCHG if SMP 445 select CPU_USE_DOMAINS if MMU 446 select NEED_KUSER_HELPERS 447 448config CPU_32v4T 449 bool 450 select TLS_REG_EMUL if SMP || !MMU 451 select NEEDS_SYSCALL_FOR_CMPXCHG if SMP 452 select CPU_USE_DOMAINS if MMU 453 select NEED_KUSER_HELPERS 454 455config CPU_32v5 456 bool 457 select TLS_REG_EMUL if SMP || !MMU 458 select NEEDS_SYSCALL_FOR_CMPXCHG if SMP 459 select CPU_USE_DOMAINS if MMU 460 select NEED_KUSER_HELPERS 461 462config CPU_32v6 463 bool 464 select TLS_REG_EMUL if !CPU_32v6K && !MMU 465 select CPU_USE_DOMAINS if CPU_V6 && MMU 466 467config CPU_32v6K 468 bool 469 470config CPU_32v7 471 bool 472 473# The abort model 474config CPU_ABRT_NOMMU 475 bool 476 477config CPU_ABRT_EV4 478 bool 479 480config CPU_ABRT_EV4T 481 bool 482 483config CPU_ABRT_LV4T 484 bool 485 486config CPU_ABRT_EV5T 487 bool 488 489config CPU_ABRT_EV5TJ 490 bool 491 492config CPU_ABRT_EV6 493 bool 494 495config CPU_ABRT_EV7 496 bool 497 498config CPU_PABRT_LEGACY 499 bool 500 501config CPU_PABRT_V6 502 bool 503 504config CPU_PABRT_V7 505 bool 506 507# The cache model 508config CPU_CACHE_V3 509 bool 510 511config CPU_CACHE_V4 512 bool 513 514config CPU_CACHE_V4WT 515 bool 516 517config CPU_CACHE_V4WB 518 bool 519 520config CPU_CACHE_V6 521 bool 522 523config CPU_CACHE_V7 524 bool 525 526config CPU_CACHE_VIVT 527 bool 528 529config CPU_CACHE_VIPT 530 bool 531 532config CPU_CACHE_FA 533 bool 534 535if MMU 536# The copy-page model 537config CPU_COPY_V3 538 bool 539 540config CPU_COPY_V4WT 541 bool 542 543config CPU_COPY_V4WB 544 bool 545 546config CPU_COPY_FEROCEON 547 bool 548 549config CPU_COPY_FA 550 bool 551 552config CPU_COPY_V6 553 bool 554 555# This selects the TLB model 556config CPU_TLB_V3 557 bool 558 help 559 ARM Architecture Version 3 TLB. 560 561config CPU_TLB_V4WT 562 bool 563 help 564 ARM Architecture Version 4 TLB with writethrough cache. 565 566config CPU_TLB_V4WB 567 bool 568 help 569 ARM Architecture Version 4 TLB with writeback cache. 570 571config CPU_TLB_V4WBI 572 bool 573 help 574 ARM Architecture Version 4 TLB with writeback cache and invalidate 575 instruction cache entry. 576 577config CPU_TLB_FEROCEON 578 bool 579 help 580 Feroceon TLB (v4wbi with non-outer-cachable page table walks). 581 582config CPU_TLB_FA 583 bool 584 help 585 Faraday ARM FA526 architecture, unified TLB with writeback cache 586 and invalidate instruction cache entry. Branch target buffer is 587 also supported. 588 589config CPU_TLB_V6 590 bool 591 592config CPU_TLB_V7 593 bool 594 595config VERIFY_PERMISSION_FAULT 596 bool 597endif 598 599config CPU_HAS_ASID 600 bool 601 help 602 This indicates whether the CPU has the ASID register; used to 603 tag TLB and possibly cache entries. 604 605config CPU_CP15 606 bool 607 help 608 Processor has the CP15 register. 609 610config CPU_CP15_MMU 611 bool 612 select CPU_CP15 613 help 614 Processor has the CP15 register, which has MMU related registers. 615 616config CPU_CP15_MPU 617 bool 618 select CPU_CP15 619 help 620 Processor has the CP15 register, which has MPU related registers. 621 622config CPU_USE_DOMAINS 623 bool 624 help 625 This option enables or disables the use of domain switching 626 via the set_fs() function. 627 628# 629# CPU supports 36-bit I/O 630# 631config IO_36 632 bool 633 634comment "Processor Features" 635 636config ARM_LPAE 637 bool "Support for the Large Physical Address Extension" 638 depends on MMU && CPU_32v7 && !CPU_32v6 && !CPU_32v5 && \ 639 !CPU_32v4 && !CPU_32v3 640 help 641 Say Y if you have an ARMv7 processor supporting the LPAE page 642 table format and you would like to access memory beyond the 643 4GB limit. The resulting kernel image will not run on 644 processors without the LPA extension. 645 646 If unsure, say N. 647 648config ARCH_PHYS_ADDR_T_64BIT 649 def_bool ARM_LPAE 650 651config ARCH_DMA_ADDR_T_64BIT 652 bool 653 654config ARM_THUMB 655 bool "Support Thumb user binaries" 656 depends on CPU_ARM720T || CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || CPU_ARM1020 || CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_V6 || CPU_V6K || CPU_V7 || CPU_FEROCEON 657 default y 658 help 659 Say Y if you want to include kernel support for running user space 660 Thumb binaries. 661 662 The Thumb instruction set is a compressed form of the standard ARM 663 instruction set resulting in smaller binaries at the expense of 664 slightly less efficient code. 665 666 If you don't know what this all is, saying Y is a safe choice. 667 668config ARM_THUMBEE 669 bool "Enable ThumbEE CPU extension" 670 depends on CPU_V7 671 help 672 Say Y here if you have a CPU with the ThumbEE extension and code to 673 make use of it. Say N for code that can run on CPUs without ThumbEE. 674 675config SWP_EMULATE 676 bool "Emulate SWP/SWPB instructions" 677 depends on !CPU_USE_DOMAINS && CPU_V7 678 select HAVE_PROC_CPU if PROC_FS 679 default y if SMP 680 help 681 ARMv6 architecture deprecates use of the SWP/SWPB instructions. 682 ARMv7 multiprocessing extensions introduce the ability to disable 683 these instructions, triggering an undefined instruction exception 684 when executed. Say Y here to enable software emulation of these 685 instructions for userspace (not kernel) using LDREX/STREX. 686 Also creates /proc/cpu/swp_emulation for statistics. 687 688 In some older versions of glibc [<=2.8] SWP is used during futex 689 trylock() operations with the assumption that the code will not 690 be preempted. This invalid assumption may be more likely to fail 691 with SWP emulation enabled, leading to deadlock of the user 692 application. 693 694 NOTE: when accessing uncached shared regions, LDREX/STREX rely 695 on an external transaction monitoring block called a global 696 monitor to maintain update atomicity. If your system does not 697 implement a global monitor, this option can cause programs that 698 perform SWP operations to uncached memory to deadlock. 699 700 If unsure, say Y. 701 702config CPU_BIG_ENDIAN 703 bool "Build big-endian kernel" 704 depends on ARCH_SUPPORTS_BIG_ENDIAN 705 help 706 Say Y if you plan on running a kernel in big-endian mode. 707 Note that your board must be properly built and your board 708 port must properly enable any big-endian related features 709 of your chipset/board/processor. 710 711config CPU_ENDIAN_BE8 712 bool 713 depends on CPU_BIG_ENDIAN 714 default CPU_V6 || CPU_V6K || CPU_V7 715 help 716 Support for the BE-8 (big-endian) mode on ARMv6 and ARMv7 processors. 717 718config CPU_ENDIAN_BE32 719 bool 720 depends on CPU_BIG_ENDIAN 721 default !CPU_ENDIAN_BE8 722 help 723 Support for the BE-32 (big-endian) mode on pre-ARMv6 processors. 724 725config CPU_HIGH_VECTOR 726 depends on !MMU && CPU_CP15 && !CPU_ARM740T 727 bool "Select the High exception vector" 728 help 729 Say Y here to select high exception vector(0xFFFF0000~). 730 The exception vector can vary depending on the platform 731 design in nommu mode. If your platform needs to select 732 high exception vector, say Y. 733 Otherwise or if you are unsure, say N, and the low exception 734 vector (0x00000000~) will be used. 735 736config CPU_ICACHE_DISABLE 737 bool "Disable I-Cache (I-bit)" 738 depends on CPU_CP15 && !(CPU_ARM610 || CPU_ARM710 || CPU_ARM720T || CPU_ARM740T || CPU_XSCALE || CPU_XSC3) 739 help 740 Say Y here to disable the processor instruction cache. Unless 741 you have a reason not to or are unsure, say N. 742 743config CPU_DCACHE_DISABLE 744 bool "Disable D-Cache (C-bit)" 745 depends on CPU_CP15 746 help 747 Say Y here to disable the processor data cache. Unless 748 you have a reason not to or are unsure, say N. 749 750config CPU_DCACHE_SIZE 751 hex 752 depends on CPU_ARM740T || CPU_ARM946E 753 default 0x00001000 if CPU_ARM740T 754 default 0x00002000 # default size for ARM946E-S 755 help 756 Some cores are synthesizable to have various sized cache. For 757 ARM946E-S case, it can vary from 0KB to 1MB. 758 To support such cache operations, it is efficient to know the size 759 before compile time. 760 If your SoC is configured to have a different size, define the value 761 here with proper conditions. 762 763config CPU_DCACHE_WRITETHROUGH 764 bool "Force write through D-cache" 765 depends on (CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || CPU_ARM1020 || CPU_FA526) && !CPU_DCACHE_DISABLE 766 default y if CPU_ARM925T 767 help 768 Say Y here to use the data cache in writethrough mode. Unless you 769 specifically require this or are unsure, say N. 770 771config CPU_CACHE_ROUND_ROBIN 772 bool "Round robin I and D cache replacement algorithm" 773 depends on (CPU_ARM926T || CPU_ARM946E || CPU_ARM1020) && (!CPU_ICACHE_DISABLE || !CPU_DCACHE_DISABLE) 774 help 775 Say Y here to use the predictable round-robin cache replacement 776 policy. Unless you specifically require this or are unsure, say N. 777 778config CPU_BPREDICT_DISABLE 779 bool "Disable branch prediction" 780 depends on CPU_ARM1020 || CPU_V6 || CPU_V6K || CPU_MOHAWK || CPU_XSC3 || CPU_V7 || CPU_FA526 781 help 782 Say Y here to disable branch prediction. If unsure, say N. 783 784config TLS_REG_EMUL 785 bool 786 select NEED_KUSER_HELPERS 787 help 788 An SMP system using a pre-ARMv6 processor (there are apparently 789 a few prototypes like that in existence) and therefore access to 790 that required register must be emulated. 791 792config NEEDS_SYSCALL_FOR_CMPXCHG 793 bool 794 select NEED_KUSER_HELPERS 795 help 796 SMP on a pre-ARMv6 processor? Well OK then. 797 Forget about fast user space cmpxchg support. 798 It is just not possible. 799 800config NEED_KUSER_HELPERS 801 bool 802 803config KUSER_HELPERS 804 bool "Enable kuser helpers in vector page" if !NEED_KUSER_HELPERS 805 default y 806 help 807 Warning: disabling this option may break user programs. 808 809 Provide kuser helpers in the vector page. The kernel provides 810 helper code to userspace in read only form at a fixed location 811 in the high vector page to allow userspace to be independent of 812 the CPU type fitted to the system. This permits binaries to be 813 run on ARMv4 through to ARMv7 without modification. 814 815 However, the fixed address nature of these helpers can be used 816 by ROP (return orientated programming) authors when creating 817 exploits. 818 819 If all of the binaries and libraries which run on your platform 820 are built specifically for your platform, and make no use of 821 these helpers, then you can turn this option off. However, 822 when such an binary or library is run, it will receive a SIGILL 823 signal, which will terminate the program. 824 825 Say N here only if you are absolutely certain that you do not 826 need these helpers; otherwise, the safe option is to say Y. 827 828config DMA_CACHE_RWFO 829 bool "Enable read/write for ownership DMA cache maintenance" 830 depends on CPU_V6K && SMP 831 default y 832 help 833 The Snoop Control Unit on ARM11MPCore does not detect the 834 cache maintenance operations and the dma_{map,unmap}_area() 835 functions may leave stale cache entries on other CPUs. By 836 enabling this option, Read or Write For Ownership in the ARMv6 837 DMA cache maintenance functions is performed. These LDR/STR 838 instructions change the cache line state to shared or modified 839 so that the cache operation has the desired effect. 840 841 Note that the workaround is only valid on processors that do 842 not perform speculative loads into the D-cache. For such 843 processors, if cache maintenance operations are not broadcast 844 in hardware, other workarounds are needed (e.g. cache 845 maintenance broadcasting in software via FIQ). 846 847config OUTER_CACHE 848 bool 849 850config OUTER_CACHE_SYNC 851 bool 852 help 853 The outer cache has a outer_cache_fns.sync function pointer 854 that can be used to drain the write buffer of the outer cache. 855 856config CACHE_FEROCEON_L2 857 bool "Enable the Feroceon L2 cache controller" 858 depends on ARCH_KIRKWOOD || ARCH_MV78XX0 859 default y 860 select OUTER_CACHE 861 help 862 This option enables the Feroceon L2 cache controller. 863 864config CACHE_FEROCEON_L2_WRITETHROUGH 865 bool "Force Feroceon L2 cache write through" 866 depends on CACHE_FEROCEON_L2 867 help 868 Say Y here to use the Feroceon L2 cache in writethrough mode. 869 Unless you specifically require this, say N for writeback mode. 870 871config MIGHT_HAVE_CACHE_L2X0 872 bool 873 help 874 This option should be selected by machines which have a L2x0 875 or PL310 cache controller, but where its use is optional. 876 877 The only effect of this option is to make CACHE_L2X0 and 878 related options available to the user for configuration. 879 880 Boards or SoCs which always require the cache controller 881 support to be present should select CACHE_L2X0 directly 882 instead of this option, thus preventing the user from 883 inadvertently configuring a broken kernel. 884 885config CACHE_L2X0 886 bool "Enable the L2x0 outer cache controller" if MIGHT_HAVE_CACHE_L2X0 887 default MIGHT_HAVE_CACHE_L2X0 888 select OUTER_CACHE 889 select OUTER_CACHE_SYNC 890 help 891 This option enables the L2x0 PrimeCell. 892 893config CACHE_PL310 894 bool 895 depends on CACHE_L2X0 896 default y if CPU_V7 && !(CPU_V6 || CPU_V6K) 897 help 898 This option enables optimisations for the PL310 cache 899 controller. 900 901config CACHE_TAUROS2 902 bool "Enable the Tauros2 L2 cache controller" 903 depends on (ARCH_DOVE || ARCH_MMP || CPU_PJ4) 904 default y 905 select OUTER_CACHE 906 help 907 This option enables the Tauros2 L2 cache controller (as 908 found on PJ1/PJ4). 909 910config CACHE_XSC3L2 911 bool "Enable the L2 cache on XScale3" 912 depends on CPU_XSC3 913 default y 914 select OUTER_CACHE 915 help 916 This option enables the L2 cache on XScale3. 917 918config ARM_L1_CACHE_SHIFT_6 919 bool 920 default y if CPU_V7 921 help 922 Setting ARM L1 cache line size to 64 Bytes. 923 924config ARM_L1_CACHE_SHIFT 925 int 926 default 6 if ARM_L1_CACHE_SHIFT_6 927 default 5 928 929config ARM_DMA_MEM_BUFFERABLE 930 bool "Use non-cacheable memory for DMA" if (CPU_V6 || CPU_V6K) && !CPU_V7 931 depends on !(MACH_REALVIEW_PB1176 || REALVIEW_EB_ARM11MP || \ 932 MACH_REALVIEW_PB11MP) 933 default y if CPU_V6 || CPU_V6K || CPU_V7 934 help 935 Historically, the kernel has used strongly ordered mappings to 936 provide DMA coherent memory. With the advent of ARMv7, mapping 937 memory with differing types results in unpredictable behaviour, 938 so on these CPUs, this option is forced on. 939 940 Multiple mappings with differing attributes is also unpredictable 941 on ARMv6 CPUs, but since they do not have aggressive speculative 942 prefetch, no harm appears to occur. 943 944 However, drivers may be missing the necessary barriers for ARMv6, 945 and therefore turning this on may result in unpredictable driver 946 behaviour. Therefore, we offer this as an option. 947 948 You are recommended say 'Y' here and debug any affected drivers. 949 950config ARCH_HAS_BARRIERS 951 bool 952 help 953 This option allows the use of custom mandatory barriers 954 included via the mach/barriers.h file. 955