arch/arm/mm/Kconfig

   1 comment "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
   8 config 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
  25 config 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
  40 config 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
  59 config 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
  77 config 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
  94 config 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
 109 config 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
 127 config 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
 146 config 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
 165 config 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
 183 config 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
 201 config 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
 219 config 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
 236 config 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
 254 config 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
 267 config 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
 285 config 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
 302 config 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
 323 config 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
 334 config 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
 344 config 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)
 355 config 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
 366 config 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
 376 config 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
 386 config CPU_PJ4
 387         bool
 388         select CPU_V7
 389         select ARM_THUMBEE
 390
 391 # ARMv6
 392 config 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
 405 config 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
 419 config 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.
 434 config 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
 440 config CPU_32v4
 441         bool
 442         select TLS_REG_EMUL if SMP || !MMU
 443         select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
 444         select CPU_USE_DOMAINS if MMU
 445
 446 config CPU_32v4T
 447         bool
 448         select TLS_REG_EMUL if SMP || !MMU
 449         select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
 450         select CPU_USE_DOMAINS if MMU
 451
 452 config CPU_32v5
 453         bool
 454         select TLS_REG_EMUL if SMP || !MMU
 455         select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
 456         select CPU_USE_DOMAINS if MMU
 457
 458 config CPU_32v6
 459         bool
 460         select TLS_REG_EMUL if !CPU_32v6K && !MMU
 461         select CPU_USE_DOMAINS if CPU_V6 && MMU
 462
 463 config CPU_32v6K
 464         bool
 465
 466 config CPU_32v7
 467         bool
 468
 469 # The abort model
 470 config CPU_ABRT_NOMMU
 471         bool
 472
 473 config CPU_ABRT_EV4
 474         bool
 475
 476 config CPU_ABRT_EV4T
 477         bool
 478
 479 config CPU_ABRT_LV4T
 480         bool
 481
 482 config CPU_ABRT_EV5T
 483         bool
 484
 485 config CPU_ABRT_EV5TJ
 486         bool
 487
 488 config CPU_ABRT_EV6
 489         bool
 490
 491 config CPU_ABRT_EV7
 492         bool
 493
 494 config CPU_PABRT_LEGACY
 495         bool
 496
 497 config CPU_PABRT_V6
 498         bool
 499
 500 config CPU_PABRT_V7
 501         bool
 502
 503 # The cache model
 504 config CPU_CACHE_V3
 505         bool
 506
 507 config CPU_CACHE_V4
 508         bool
 509
 510 config CPU_CACHE_V4WT
 511         bool
 512
 513 config CPU_CACHE_V4WB
 514         bool
 515
 516 config CPU_CACHE_V6
 517         bool
 518
 519 config CPU_CACHE_V7
 520         bool
 521
 522 config CPU_CACHE_VIVT
 523         bool
 524
 525 config CPU_CACHE_VIPT
 526         bool
 527
 528 config CPU_CACHE_FA
 529         bool
 530
 531 if MMU
 532 # The copy-page model
 533 config CPU_COPY_V3
 534         bool
 535
 536 config CPU_COPY_V4WT
 537         bool
 538
 539 config CPU_COPY_V4WB
 540         bool
 541
 542 config CPU_COPY_FEROCEON
 543         bool
 544
 545 config CPU_COPY_FA
 546         bool
 547
 548 config CPU_COPY_V6
 549         bool
 550
 551 # This selects the TLB model
 552 config CPU_TLB_V3
 553         bool
 554         help
 555           ARM Architecture Version 3 TLB.
 556
 557 config CPU_TLB_V4WT
 558         bool
 559         help
 560           ARM Architecture Version 4 TLB with writethrough cache.
 561
 562 config CPU_TLB_V4WB
 563         bool
 564         help
 565           ARM Architecture Version 4 TLB with writeback cache.
 566
 567 config CPU_TLB_V4WBI
 568         bool
 569         help
 570           ARM Architecture Version 4 TLB with writeback cache and invalidate
 571           instruction cache entry.
 572
 573 config CPU_TLB_FEROCEON
 574         bool
 575         help
 576           Feroceon TLB (v4wbi with non-outer-cachable page table walks).
 577
 578 config CPU_TLB_FA
 579         bool
 580         help
 581           Faraday ARM FA526 architecture, unified TLB with writeback cache
 582           and invalidate instruction cache entry. Branch target buffer is
 583           also supported.
 584
 585 config CPU_TLB_V6
 586         bool
 587
 588 config CPU_TLB_V7
 589         bool
 590
 591 config VERIFY_PERMISSION_FAULT
 592         bool
 593 endif
 594
 595 config CPU_HAS_ASID
 596         bool
 597         help
 598           This indicates whether the CPU has the ASID register; used to
 599           tag TLB and possibly cache entries.
 600
 601 config CPU_CP15
 602         bool
 603         help
 604           Processor has the CP15 register.
 605
 606 config CPU_CP15_MMU
 607         bool
 608         select CPU_CP15
 609         help
 610           Processor has the CP15 register, which has MMU related registers.
 611
 612 config CPU_CP15_MPU
 613         bool
 614         select CPU_CP15
 615         help
 616           Processor has the CP15 register, which has MPU related registers.
 617
 618 config CPU_USE_DOMAINS
 619         bool
 620         help
 621           This option enables or disables the use of domain switching
 622           via the set_fs() function.
 623
 624 #
 625 # CPU supports 36-bit I/O
 626 #
 627 config IO_36
 628         bool
 629
 630 comment "Processor Features"
 631
 632 config ARM_LPAE
 633         bool "Support for the Large Physical Address Extension"
 634         depends on MMU && CPU_V7
 635         help
 636           Say Y if you have an ARMv7 processor supporting the LPAE page
 637           table format and you would like to access memory beyond the
 638           4GB limit. The resulting kernel image will not run on
 639           processors without the LPA extension.
 640
 641           If unsure, say N.
 642
 643 config ARCH_PHYS_ADDR_T_64BIT
 644         def_bool ARM_LPAE
 645
 646 config ARCH_DMA_ADDR_T_64BIT
 647         bool
 648
 649 config ARM_THUMB
 650         bool "Support Thumb user binaries"
 651         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
 652         default y
 653         help
 654           Say Y if you want to include kernel support for running user space
 655           Thumb binaries.
 656
 657           The Thumb instruction set is a compressed form of the standard ARM
 658           instruction set resulting in smaller binaries at the expense of
 659           slightly less efficient code.
 660
 661           If you don't know what this all is, saying Y is a safe choice.
 662
 663 config ARM_THUMBEE
 664         bool "Enable ThumbEE CPU extension"
 665         depends on CPU_V7
 666         help
 667           Say Y here if you have a CPU with the ThumbEE extension and code to
 668           make use of it. Say N for code that can run on CPUs without ThumbEE.
 669
 670 config SWP_EMULATE
 671         bool "Emulate SWP/SWPB instructions"
 672         depends on !CPU_USE_DOMAINS && CPU_V7
 673         select HAVE_PROC_CPU if PROC_FS
 674         default y if SMP
 675         help
 676           ARMv6 architecture deprecates use of the SWP/SWPB instructions.
 677           ARMv7 multiprocessing extensions introduce the ability to disable
 678           these instructions, triggering an undefined instruction exception
 679           when executed. Say Y here to enable software emulation of these
 680           instructions for userspace (not kernel) using LDREX/STREX.
 681           Also creates /proc/cpu/swp_emulation for statistics.
 682
 683           In some older versions of glibc [<=2.8] SWP is used during futex
 684           trylock() operations with the assumption that the code will not
 685           be preempted. This invalid assumption may be more likely to fail
 686           with SWP emulation enabled, leading to deadlock of the user
 687           application.
 688
 689           NOTE: when accessing uncached shared regions, LDREX/STREX rely
 690           on an external transaction monitoring block called a global
 691           monitor to maintain update atomicity. If your system does not
 692           implement a global monitor, this option can cause programs that
 693           perform SWP operations to uncached memory to deadlock.
 694
 695           If unsure, say Y.
 696
 697 config CPU_BIG_ENDIAN
 698         bool "Build big-endian kernel"
 699         depends on ARCH_SUPPORTS_BIG_ENDIAN
 700         help
 701           Say Y if you plan on running a kernel in big-endian mode.
 702           Note that your board must be properly built and your board
 703           port must properly enable any big-endian related features
 704           of your chipset/board/processor.
 705
 706 config CPU_ENDIAN_BE8
 707         bool
 708         depends on CPU_BIG_ENDIAN
 709         default CPU_V6 || CPU_V6K || CPU_V7
 710         help
 711           Support for the BE-8 (big-endian) mode on ARMv6 and ARMv7 processors.
 712
 713 config CPU_ENDIAN_BE32
 714         bool
 715         depends on CPU_BIG_ENDIAN
 716         default !CPU_ENDIAN_BE8
 717         help
 718           Support for the BE-32 (big-endian) mode on pre-ARMv6 processors.
 719
 720 config CPU_HIGH_VECTOR
 721         depends on !MMU && CPU_CP15 && !CPU_ARM740T
 722         bool "Select the High exception vector"
 723         help
 724           Say Y here to select high exception vector(0xFFFF0000~).
 725           The exception vector can be vary depending on the platform
 726           design in nommu mode. If your platform needs to select
 727           high exception vector, say Y.
 728           Otherwise or if you are unsure, say N, and the low exception
 729           vector (0x00000000~) will be used.
 730
 731 config CPU_ICACHE_DISABLE
 732         bool "Disable I-Cache (I-bit)"
 733         depends on CPU_CP15 && !(CPU_ARM610 || CPU_ARM710 || CPU_ARM720T || CPU_ARM740T || CPU_XSCALE || CPU_XSC3)
 734         help
 735           Say Y here to disable the processor instruction cache. Unless
 736           you have a reason not to or are unsure, say N.
 737
 738 config CPU_DCACHE_DISABLE
 739         bool "Disable D-Cache (C-bit)"
 740         depends on CPU_CP15
 741         help
 742           Say Y here to disable the processor data cache. Unless
 743           you have a reason not to or are unsure, say N.
 744
 745 config CPU_DCACHE_SIZE
 746         hex
 747         depends on CPU_ARM740T || CPU_ARM946E
 748         default 0x00001000 if CPU_ARM740T
 749         default 0x00002000 # default size for ARM946E-S
 750         help
 751           Some cores are synthesizable to have various sized cache. For
 752           ARM946E-S case, it can vary from 0KB to 1MB.
 753           To support such cache operations, it is efficient to know the size
 754           before compile time.
 755           If your SoC is configured to have a different size, define the value
 756           here with proper conditions.
 757
 758 config CPU_DCACHE_WRITETHROUGH
 759         bool "Force write through D-cache"
 760         depends on (CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || CPU_ARM1020 || CPU_FA526) && !CPU_DCACHE_DISABLE
 761         default y if CPU_ARM925T
 762         help
 763           Say Y here to use the data cache in writethrough mode. Unless you
 764           specifically require this or are unsure, say N.
 765
 766 config CPU_CACHE_ROUND_ROBIN
 767         bool "Round robin I and D cache replacement algorithm"
 768         depends on (CPU_ARM926T || CPU_ARM946E || CPU_ARM1020) && (!CPU_ICACHE_DISABLE || !CPU_DCACHE_DISABLE)
 769         help
 770           Say Y here to use the predictable round-robin cache replacement
 771           policy.  Unless you specifically require this or are unsure, say N.
 772
 773 config CPU_BPREDICT_DISABLE
 774         bool "Disable branch prediction"
 775         depends on CPU_ARM1020 || CPU_V6 || CPU_V6K || CPU_MOHAWK || CPU_XSC3 || CPU_V7 || CPU_FA526
 776         help
 777           Say Y here to disable branch prediction.  If unsure, say N.
 778
 779 config TLS_REG_EMUL
 780         bool
 781         help
 782           An SMP system using a pre-ARMv6 processor (there are apparently
 783           a few prototypes like that in existence) and therefore access to
 784           that required register must be emulated.
 785
 786 config NEEDS_SYSCALL_FOR_CMPXCHG
 787         bool
 788         help
 789           SMP on a pre-ARMv6 processor?  Well OK then.
 790           Forget about fast user space cmpxchg support.
 791           It is just not possible.
 792
 793 config DMA_CACHE_RWFO
 794         bool "Enable read/write for ownership DMA cache maintenance"
 795         depends on CPU_V6K && SMP
 796         default y
 797         help
 798           The Snoop Control Unit on ARM11MPCore does not detect the
 799           cache maintenance operations and the dma_{map,unmap}_area()
 800           functions may leave stale cache entries on other CPUs. By
 801           enabling this option, Read or Write For Ownership in the ARMv6
 802           DMA cache maintenance functions is performed. These LDR/STR
 803           instructions change the cache line state to shared or modified
 804           so that the cache operation has the desired effect.
 805
 806           Note that the workaround is only valid on processors that do
 807           not perform speculative loads into the D-cache. For such
 808           processors, if cache maintenance operations are not broadcast
 809           in hardware, other workarounds are needed (e.g. cache
 810           maintenance broadcasting in software via FIQ).
 811
 812 config OUTER_CACHE
 813         bool
 814
 815 config OUTER_CACHE_SYNC
 816         bool
 817         help
 818           The outer cache has a outer_cache_fns.sync function pointer
 819           that can be used to drain the write buffer of the outer cache.
 820
 821 config CACHE_FEROCEON_L2
 822         bool "Enable the Feroceon L2 cache controller"
 823         depends on ARCH_KIRKWOOD || ARCH_MV78XX0
 824         default y
 825         select OUTER_CACHE
 826         help
 827           This option enables the Feroceon L2 cache controller.
 828
 829 config CACHE_FEROCEON_L2_WRITETHROUGH
 830         bool "Force Feroceon L2 cache write through"
 831         depends on CACHE_FEROCEON_L2
 832         help
 833           Say Y here to use the Feroceon L2 cache in writethrough mode.
 834           Unless you specifically require this, say N for writeback mode.
 835
 836 config MIGHT_HAVE_CACHE_L2X0
 837         bool
 838         help
 839           This option should be selected by machines which have a L2x0
 840           or PL310 cache controller, but where its use is optional.
 841
 842           The only effect of this option is to make CACHE_L2X0 and
 843           related options available to the user for configuration.
 844
 845           Boards or SoCs which always require the cache controller
 846           support to be present should select CACHE_L2X0 directly
 847           instead of this option, thus preventing the user from
 848           inadvertently configuring a broken kernel.
 849
 850 config CACHE_L2X0
 851         bool "Enable the L2x0 outer cache controller" if MIGHT_HAVE_CACHE_L2X0
 852         default MIGHT_HAVE_CACHE_L2X0
 853         select OUTER_CACHE
 854         select OUTER_CACHE_SYNC
 855         help
 856           This option enables the L2x0 PrimeCell.
 857
 858 config CACHE_PL310
 859         bool
 860         depends on CACHE_L2X0
 861         default y if CPU_V7 && !(CPU_V6 || CPU_V6K)
 862         help
 863           This option enables optimisations for the PL310 cache
 864           controller.
 865
 866 config CACHE_TAUROS2
 867         bool "Enable the Tauros2 L2 cache controller"
 868         depends on (ARCH_DOVE || ARCH_MMP || CPU_PJ4)
 869         default y
 870         select OUTER_CACHE
 871         help
 872           This option enables the Tauros2 L2 cache controller (as
 873           found on PJ1/PJ4).
 874
 875 config CACHE_XSC3L2
 876         bool "Enable the L2 cache on XScale3"
 877         depends on CPU_XSC3
 878         default y
 879         select OUTER_CACHE
 880         help
 881           This option enables the L2 cache on XScale3.
 882
 883 config ARM_L1_CACHE_SHIFT_6
 884         bool
 885         default y if CPU_V7
 886         help
 887           Setting ARM L1 cache line size to 64 Bytes.
 888
 889 config ARM_L1_CACHE_SHIFT
 890         int
 891         default 6 if ARM_L1_CACHE_SHIFT_6
 892         default 5
 893
 894 config ARM_DMA_MEM_BUFFERABLE
 895         bool "Use non-cacheable memory for DMA" if (CPU_V6 || CPU_V6K) && !CPU_V7
 896         depends on !(MACH_REALVIEW_PB1176 || REALVIEW_EB_ARM11MP || \
 897                      MACH_REALVIEW_PB11MP)
 898         default y if CPU_V6 || CPU_V6K || CPU_V7
 899         help
 900           Historically, the kernel has used strongly ordered mappings to
 901           provide DMA coherent memory.  With the advent of ARMv7, mapping
 902           memory with differing types results in unpredictable behaviour,
 903           so on these CPUs, this option is forced on.
 904
 905           Multiple mappings with differing attributes is also unpredictable
 906           on ARMv6 CPUs, but since they do not have aggressive speculative
 907           prefetch, no harm appears to occur.
 908
 909           However, drivers may be missing the necessary barriers for ARMv6,
 910           and therefore turning this on may result in unpredictable driver
 911           behaviour.  Therefore, we offer this as an option.
 912
 913           You are recommended say 'Y' here and debug any affected drivers.
 914
 915 config ARCH_HAS_BARRIERS
 916         bool
 917         help
 918           This option allows the use of custom mandatory barriers
 919           included via the mach/barriers.h file.