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# ARMv6 386config CPU_V6 387 bool "Support ARM V6 processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB || MACH_REALVIEW_PBX || ARCH_DOVE 388 select CPU_32v6 389 select CPU_ABRT_EV6 390 select CPU_PABRT_V6 391 select CPU_CACHE_V6 392 select CPU_CACHE_VIPT 393 select CPU_CP15_MMU 394 select CPU_HAS_ASID if MMU 395 select CPU_COPY_V6 if MMU 396 select CPU_TLB_V6 if MMU 397 398# ARMv6k 399config CPU_32v6K 400 bool "Support ARM V6K processor extensions" if !SMP 401 depends on CPU_V6 402 default y if SMP && !(ARCH_MX3 || ARCH_OMAP2) 403 help 404 Say Y here if your ARMv6 processor supports the 'K' extension. 405 This enables the kernel to use some instructions not present 406 on previous processors, and as such a kernel build with this 407 enabled will not boot on processors with do not support these 408 instructions. 409 410# ARMv7 411config CPU_V7 412 bool "Support ARM V7 processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB || MACH_REALVIEW_PBX 413 select CPU_32v6K if !ARCH_OMAP2 414 select CPU_32v7 415 select CPU_ABRT_EV7 416 select CPU_PABRT_V7 417 select CPU_CACHE_V7 418 select CPU_CACHE_VIPT 419 select CPU_CP15_MMU 420 select CPU_HAS_ASID if MMU 421 select CPU_COPY_V6 if MMU 422 select CPU_TLB_V7 if MMU 423 424# Figure out what processor architecture version we should be using. 425# This defines the compiler instruction set which depends on the machine type. 426config CPU_32v3 427 bool 428 select TLS_REG_EMUL if SMP || !MMU 429 select NEEDS_SYSCALL_FOR_CMPXCHG if SMP 430 431config CPU_32v4 432 bool 433 select TLS_REG_EMUL if SMP || !MMU 434 select NEEDS_SYSCALL_FOR_CMPXCHG if SMP 435 436config CPU_32v4T 437 bool 438 select TLS_REG_EMUL if SMP || !MMU 439 select NEEDS_SYSCALL_FOR_CMPXCHG if SMP 440 441config CPU_32v5 442 bool 443 select TLS_REG_EMUL if SMP || !MMU 444 select NEEDS_SYSCALL_FOR_CMPXCHG if SMP 445 446config CPU_32v6 447 bool 448 select TLS_REG_EMUL if !CPU_32v6K && !MMU 449 450config CPU_32v7 451 bool 452 453# The abort model 454config CPU_ABRT_NOMMU 455 bool 456 457config CPU_ABRT_EV4 458 bool 459 460config CPU_ABRT_EV4T 461 bool 462 463config CPU_ABRT_LV4T 464 bool 465 466config CPU_ABRT_EV5T 467 bool 468 469config CPU_ABRT_EV5TJ 470 bool 471 472config CPU_ABRT_EV6 473 bool 474 475config CPU_ABRT_EV7 476 bool 477 478config CPU_PABRT_LEGACY 479 bool 480 481config CPU_PABRT_V6 482 bool 483 484config CPU_PABRT_V7 485 bool 486 487# The cache model 488config CPU_CACHE_V3 489 bool 490 491config CPU_CACHE_V4 492 bool 493 494config CPU_CACHE_V4WT 495 bool 496 497config CPU_CACHE_V4WB 498 bool 499 500config CPU_CACHE_V6 501 bool 502 503config CPU_CACHE_V7 504 bool 505 506config CPU_CACHE_VIVT 507 bool 508 509config CPU_CACHE_VIPT 510 bool 511 512config CPU_CACHE_FA 513 bool 514 515if MMU 516# The copy-page model 517config CPU_COPY_V3 518 bool 519 520config CPU_COPY_V4WT 521 bool 522 523config CPU_COPY_V4WB 524 bool 525 526config CPU_COPY_FEROCEON 527 bool 528 529config CPU_COPY_FA 530 bool 531 532config CPU_COPY_V6 533 bool 534 535# This selects the TLB model 536config CPU_TLB_V3 537 bool 538 help 539 ARM Architecture Version 3 TLB. 540 541config CPU_TLB_V4WT 542 bool 543 help 544 ARM Architecture Version 4 TLB with writethrough cache. 545 546config CPU_TLB_V4WB 547 bool 548 help 549 ARM Architecture Version 4 TLB with writeback cache. 550 551config CPU_TLB_V4WBI 552 bool 553 help 554 ARM Architecture Version 4 TLB with writeback cache and invalidate 555 instruction cache entry. 556 557config CPU_TLB_FEROCEON 558 bool 559 help 560 Feroceon TLB (v4wbi with non-outer-cachable page table walks). 561 562config CPU_TLB_FA 563 bool 564 help 565 Faraday ARM FA526 architecture, unified TLB with writeback cache 566 and invalidate instruction cache entry. Branch target buffer is 567 also supported. 568 569config CPU_TLB_V6 570 bool 571 572config CPU_TLB_V7 573 bool 574 575config VERIFY_PERMISSION_FAULT 576 bool 577endif 578 579config CPU_HAS_ASID 580 bool 581 help 582 This indicates whether the CPU has the ASID register; used to 583 tag TLB and possibly cache entries. 584 585config CPU_CP15 586 bool 587 help 588 Processor has the CP15 register. 589 590config CPU_CP15_MMU 591 bool 592 select CPU_CP15 593 help 594 Processor has the CP15 register, which has MMU related registers. 595 596config CPU_CP15_MPU 597 bool 598 select CPU_CP15 599 help 600 Processor has the CP15 register, which has MPU related registers. 601 602# 603# CPU supports 36-bit I/O 604# 605config IO_36 606 bool 607 608comment "Processor Features" 609 610config ARM_THUMB 611 bool "Support Thumb user binaries" 612 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_V7 || CPU_FEROCEON 613 default y 614 help 615 Say Y if you want to include kernel support for running user space 616 Thumb binaries. 617 618 The Thumb instruction set is a compressed form of the standard ARM 619 instruction set resulting in smaller binaries at the expense of 620 slightly less efficient code. 621 622 If you don't know what this all is, saying Y is a safe choice. 623 624config ARM_THUMBEE 625 bool "Enable ThumbEE CPU extension" 626 depends on CPU_V7 627 help 628 Say Y here if you have a CPU with the ThumbEE extension and code to 629 make use of it. Say N for code that can run on CPUs without ThumbEE. 630 631config CPU_BIG_ENDIAN 632 bool "Build big-endian kernel" 633 depends on ARCH_SUPPORTS_BIG_ENDIAN 634 help 635 Say Y if you plan on running a kernel in big-endian mode. 636 Note that your board must be properly built and your board 637 port must properly enable any big-endian related features 638 of your chipset/board/processor. 639 640config CPU_ENDIAN_BE8 641 bool 642 depends on CPU_BIG_ENDIAN 643 default CPU_V6 || CPU_V7 644 help 645 Support for the BE-8 (big-endian) mode on ARMv6 and ARMv7 processors. 646 647config CPU_ENDIAN_BE32 648 bool 649 depends on CPU_BIG_ENDIAN 650 default !CPU_ENDIAN_BE8 651 help 652 Support for the BE-32 (big-endian) mode on pre-ARMv6 processors. 653 654config CPU_HIGH_VECTOR 655 depends on !MMU && CPU_CP15 && !CPU_ARM740T 656 bool "Select the High exception vector" 657 help 658 Say Y here to select high exception vector(0xFFFF0000~). 659 The exception vector can be vary depending on the platform 660 design in nommu mode. If your platform needs to select 661 high exception vector, say Y. 662 Otherwise or if you are unsure, say N, and the low exception 663 vector (0x00000000~) will be used. 664 665config CPU_ICACHE_DISABLE 666 bool "Disable I-Cache (I-bit)" 667 depends on CPU_CP15 && !(CPU_ARM610 || CPU_ARM710 || CPU_ARM720T || CPU_ARM740T || CPU_XSCALE || CPU_XSC3) 668 help 669 Say Y here to disable the processor instruction cache. Unless 670 you have a reason not to or are unsure, say N. 671 672config CPU_DCACHE_DISABLE 673 bool "Disable D-Cache (C-bit)" 674 depends on CPU_CP15 675 help 676 Say Y here to disable the processor data cache. Unless 677 you have a reason not to or are unsure, say N. 678 679config CPU_DCACHE_SIZE 680 hex 681 depends on CPU_ARM740T || CPU_ARM946E 682 default 0x00001000 if CPU_ARM740T 683 default 0x00002000 # default size for ARM946E-S 684 help 685 Some cores are synthesizable to have various sized cache. For 686 ARM946E-S case, it can vary from 0KB to 1MB. 687 To support such cache operations, it is efficient to know the size 688 before compile time. 689 If your SoC is configured to have a different size, define the value 690 here with proper conditions. 691 692config CPU_DCACHE_WRITETHROUGH 693 bool "Force write through D-cache" 694 depends on (CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || CPU_ARM1020 || CPU_FA526) && !CPU_DCACHE_DISABLE 695 default y if CPU_ARM925T 696 help 697 Say Y here to use the data cache in writethrough mode. Unless you 698 specifically require this or are unsure, say N. 699 700config CPU_CACHE_ROUND_ROBIN 701 bool "Round robin I and D cache replacement algorithm" 702 depends on (CPU_ARM926T || CPU_ARM946E || CPU_ARM1020) && (!CPU_ICACHE_DISABLE || !CPU_DCACHE_DISABLE) 703 help 704 Say Y here to use the predictable round-robin cache replacement 705 policy. Unless you specifically require this or are unsure, say N. 706 707config CPU_BPREDICT_DISABLE 708 bool "Disable branch prediction" 709 depends on CPU_ARM1020 || CPU_V6 || CPU_MOHAWK || CPU_XSC3 || CPU_V7 || CPU_FA526 710 help 711 Say Y here to disable branch prediction. If unsure, say N. 712 713config TLS_REG_EMUL 714 bool 715 help 716 An SMP system using a pre-ARMv6 processor (there are apparently 717 a few prototypes like that in existence) and therefore access to 718 that required register must be emulated. 719 720config HAS_TLS_REG 721 bool 722 depends on !TLS_REG_EMUL 723 default y if SMP || CPU_32v7 724 help 725 This selects support for the CP15 thread register. 726 It is defined to be available on some ARMv6 processors (including 727 all SMP capable ARMv6's) or later processors. User space may 728 assume directly accessing that register and always obtain the 729 expected value only on ARMv7 and above. 730 731config NEEDS_SYSCALL_FOR_CMPXCHG 732 bool 733 help 734 SMP on a pre-ARMv6 processor? Well OK then. 735 Forget about fast user space cmpxchg support. 736 It is just not possible. 737 738config DMA_CACHE_RWFO 739 bool "Enable read/write for ownership DMA cache maintenance" 740 depends on CPU_V6 && SMP 741 default y 742 help 743 The Snoop Control Unit on ARM11MPCore does not detect the 744 cache maintenance operations and the dma_{map,unmap}_area() 745 functions may leave stale cache entries on other CPUs. By 746 enabling this option, Read or Write For Ownership in the ARMv6 747 DMA cache maintenance functions is performed. These LDR/STR 748 instructions change the cache line state to shared or modified 749 so that the cache operation has the desired effect. 750 751 Note that the workaround is only valid on processors that do 752 not perform speculative loads into the D-cache. For such 753 processors, if cache maintenance operations are not broadcast 754 in hardware, other workarounds are needed (e.g. cache 755 maintenance broadcasting in software via FIQ). 756 757config OUTER_CACHE 758 bool 759 760config OUTER_CACHE_SYNC 761 bool 762 help 763 The outer cache has a outer_cache_fns.sync function pointer 764 that can be used to drain the write buffer of the outer cache. 765 766config CACHE_FEROCEON_L2 767 bool "Enable the Feroceon L2 cache controller" 768 depends on ARCH_KIRKWOOD || ARCH_MV78XX0 769 default y 770 select OUTER_CACHE 771 help 772 This option enables the Feroceon L2 cache controller. 773 774config CACHE_FEROCEON_L2_WRITETHROUGH 775 bool "Force Feroceon L2 cache write through" 776 depends on CACHE_FEROCEON_L2 777 help 778 Say Y here to use the Feroceon L2 cache in writethrough mode. 779 Unless you specifically require this, say N for writeback mode. 780 781config CACHE_L2X0 782 bool "Enable the L2x0 outer cache controller" 783 depends on REALVIEW_EB_ARM11MP || MACH_REALVIEW_PB11MP || MACH_REALVIEW_PB1176 || \ 784 REALVIEW_EB_A9MP || ARCH_MX35 || ARCH_MX31 || MACH_REALVIEW_PBX || \ 785 ARCH_NOMADIK || ARCH_OMAP4 || ARCH_U8500 || ARCH_VEXPRESS_CA9X4 786 default y 787 select OUTER_CACHE 788 select OUTER_CACHE_SYNC 789 help 790 This option enables the L2x0 PrimeCell. 791 792config CACHE_TAUROS2 793 bool "Enable the Tauros2 L2 cache controller" 794 depends on (ARCH_DOVE || ARCH_MMP) 795 default y 796 select OUTER_CACHE 797 help 798 This option enables the Tauros2 L2 cache controller (as 799 found on PJ1/PJ4). 800 801config CACHE_XSC3L2 802 bool "Enable the L2 cache on XScale3" 803 depends on CPU_XSC3 804 default y 805 select OUTER_CACHE 806 help 807 This option enables the L2 cache on XScale3. 808 809config ARM_L1_CACHE_SHIFT 810 int 811 default 6 if ARM_L1_CACHE_SHIFT_6 812 default 5 813 814config ARM_DMA_MEM_BUFFERABLE 815 bool "Use non-cacheable memory for DMA" if CPU_V6 && !CPU_V7 816 depends on !(MACH_REALVIEW_PB1176 || REALVIEW_EB_ARM11MP || \ 817 MACH_REALVIEW_PB11MP) 818 default y if CPU_V6 || CPU_V7 819 help 820 Historically, the kernel has used strongly ordered mappings to 821 provide DMA coherent memory. With the advent of ARMv7, mapping 822 memory with differing types results in unpredictable behaviour, 823 so on these CPUs, this option is forced on. 824 825 Multiple mappings with differing attributes is also unpredictable 826 on ARMv6 CPUs, but since they do not have aggressive speculative 827 prefetch, no harm appears to occur. 828 829 However, drivers may be missing the necessary barriers for ARMv6, 830 and therefore turning this on may result in unpredictable driver 831 behaviour. Therefore, we offer this as an option. 832 833 You are recommended say 'Y' here and debug any affected drivers. 834 835config ARCH_HAS_BARRIERS 836 bool 837 help 838 This option allows the use of custom mandatory barriers 839 included via the mach/barriers.h file. 840