| blob | eda0dd0ab97bf02bc6759b2018ae05818d4006c3 |
1 comment "Processor Type"
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.
7 # ARM7TDMI
8 config CPU_ARM7TDMI
9 bool "Support ARM7TDMI processor"
10 depends on !MMU
11 select CPU_32v4T
12 select CPU_ABRT_LV4T
13 select CPU_CACHE_V4
14 select CPU_PABRT_LEGACY
15 help
16 A 32-bit RISC microprocessor based on the ARM7 processor core
17 which has no memory control unit and cache.
19 Say Y if you want support for the ARM7TDMI processor.
20 Otherwise, say N.
22 # ARM720T
23 config CPU_ARM720T
24 bool "Support ARM720T processor" if ARCH_INTEGRATOR
25 select CPU_32v4T
26 select CPU_ABRT_LV4T
27 select CPU_CACHE_V4
28 select CPU_CACHE_VIVT
29 select CPU_COPY_V4WT if MMU
30 select CPU_CP15_MMU
31 select CPU_PABRT_LEGACY
32 select CPU_TLB_V4WT if MMU
33 help
34 A 32-bit RISC processor with 8kByte Cache, Write Buffer and
35 MMU built around an ARM7TDMI core.
37 Say Y if you want support for the ARM720T processor.
38 Otherwise, say N.
40 # ARM740T
41 config CPU_ARM740T
42 bool "Support ARM740T processor" if ARCH_INTEGRATOR
43 depends on !MMU
44 select CPU_32v4T
45 select CPU_ABRT_LV4T
46 select CPU_CACHE_V4
47 select CPU_CP15_MPU
48 select CPU_PABRT_LEGACY
49 help
50 A 32-bit RISC processor with 8KB cache or 4KB variants,
51 write buffer and MPU(Protection Unit) built around
52 an ARM7TDMI core.
54 Say Y if you want support for the ARM740T processor.
55 Otherwise, say N.
57 # ARM9TDMI
58 config CPU_ARM9TDMI
59 bool "Support ARM9TDMI processor"
60 depends on !MMU
61 select CPU_32v4T
62 select CPU_ABRT_NOMMU
63 select CPU_CACHE_V4
64 select CPU_PABRT_LEGACY
65 help
66 A 32-bit RISC microprocessor based on the ARM9 processor core
67 which has no memory control unit and cache.
69 Say Y if you want support for the ARM9TDMI processor.
70 Otherwise, say N.
72 # ARM920T
73 config CPU_ARM920T
74 bool "Support ARM920T processor" if ARCH_INTEGRATOR
75 select CPU_32v4T
76 select CPU_ABRT_EV4T
77 select CPU_CACHE_V4WT
78 select CPU_CACHE_VIVT
79 select CPU_COPY_V4WB if MMU
80 select CPU_CP15_MMU
81 select CPU_PABRT_LEGACY
82 select CPU_TLB_V4WBI if MMU
83 help
84 The ARM920T is licensed to be produced by numerous vendors,
85 and is used in the Cirrus EP93xx and the Samsung S3C2410.
87 Say Y if you want support for the ARM920T processor.
88 Otherwise, say N.
90 # ARM922T
91 config CPU_ARM922T
92 bool "Support ARM922T processor" if ARCH_INTEGRATOR
93 select CPU_32v4T
94 select CPU_ABRT_EV4T
95 select CPU_CACHE_V4WT
96 select CPU_CACHE_VIVT
97 select CPU_COPY_V4WB if MMU
98 select CPU_CP15_MMU
99 select CPU_PABRT_LEGACY
100 select CPU_TLB_V4WBI if MMU
101 help
102 The ARM922T is a version of the ARM920T, but with smaller
103 instruction and data caches. It is used in Altera's
104 Excalibur XA device family and Micrel's KS8695 Centaur.
106 Say Y if you want support for the ARM922T processor.
107 Otherwise, say N.
109 # ARM925T
110 config CPU_ARM925T
111 bool "Support ARM925T processor" if ARCH_OMAP1
112 select CPU_32v4T
113 select CPU_ABRT_EV4T
114 select CPU_CACHE_V4WT
115 select CPU_CACHE_VIVT
116 select CPU_COPY_V4WB if MMU
117 select CPU_CP15_MMU
118 select CPU_PABRT_LEGACY
119 select CPU_TLB_V4WBI if MMU
120 help
121 The ARM925T is a mix between the ARM920T and ARM926T, but with
122 different instruction and data caches. It is used in TI's OMAP
123 device family.
125 Say Y if you want support for the ARM925T processor.
126 Otherwise, say N.
128 # ARM926T
129 config CPU_ARM926T
130 bool "Support ARM926T processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB
131 select CPU_32v5
132 select CPU_ABRT_EV5TJ
133 select CPU_CACHE_VIVT
134 select CPU_COPY_V4WB if MMU
135 select CPU_CP15_MMU
136 select CPU_PABRT_LEGACY
137 select CPU_TLB_V4WBI if MMU
138 help
139 This is a variant of the ARM920. It has slightly different
140 instruction sequences for cache and TLB operations. Curiously,
141 there is no documentation on it at the ARM corporate website.
143 Say Y if you want support for the ARM926T processor.
144 Otherwise, say N.
146 # FA526
147 config CPU_FA526
148 bool
149 select CPU_32v4
150 select CPU_ABRT_EV4
151 select CPU_CACHE_FA
152 select CPU_CACHE_VIVT
153 select CPU_COPY_FA if MMU
154 select CPU_CP15_MMU
155 select CPU_PABRT_LEGACY
156 select CPU_TLB_FA if MMU
157 help
158 The FA526 is a version of the ARMv4 compatible processor with
159 Branch Target Buffer, Unified TLB and cache line size 16.
161 Say Y if you want support for the FA526 processor.
162 Otherwise, say N.
164 # ARM940T
165 config CPU_ARM940T
166 bool "Support ARM940T processor" if ARCH_INTEGRATOR
167 depends on !MMU
168 select CPU_32v4T
169 select CPU_ABRT_NOMMU
170 select CPU_CACHE_VIVT
171 select CPU_CP15_MPU
172 select CPU_PABRT_LEGACY
173 help
174 ARM940T is a member of the ARM9TDMI family of general-
175 purpose microprocessors with MPU and separate 4KB
176 instruction and 4KB data cases, each with a 4-word line
177 length.
179 Say Y if you want support for the ARM940T processor.
180 Otherwise, say N.
182 # ARM946E-S
183 config CPU_ARM946E
184 bool "Support ARM946E-S processor" if ARCH_INTEGRATOR
185 depends on !MMU
186 select CPU_32v5
187 select CPU_ABRT_NOMMU
188 select CPU_CACHE_VIVT
189 select CPU_CP15_MPU
190 select CPU_PABRT_LEGACY
191 help
192 ARM946E-S is a member of the ARM9E-S family of high-
193 performance, 32-bit system-on-chip processor solutions.
194 The TCM and ARMv5TE 32-bit instruction set is supported.
196 Say Y if you want support for the ARM946E-S processor.
197 Otherwise, say N.
199 # ARM1020 - needs validating
200 config CPU_ARM1020
201 bool "Support ARM1020T (rev 0) processor" if ARCH_INTEGRATOR
202 select CPU_32v5
203 select CPU_ABRT_EV4T
204 select CPU_CACHE_V4WT
205 select CPU_CACHE_VIVT
206 select CPU_COPY_V4WB if MMU
207 select CPU_CP15_MMU
208 select CPU_PABRT_LEGACY
209 select CPU_TLB_V4WBI if MMU
210 help
211 The ARM1020 is the 32K cached version of the ARM10 processor,
212 with an addition of a floating-point unit.
214 Say Y if you want support for the ARM1020 processor.
215 Otherwise, say N.
217 # ARM1020E - needs validating
218 config CPU_ARM1020E
219 bool "Support ARM1020E processor" if ARCH_INTEGRATOR
220 depends on n
221 select CPU_32v5
222 select CPU_ABRT_EV4T
223 select CPU_CACHE_V4WT
224 select CPU_CACHE_VIVT
225 select CPU_COPY_V4WB if MMU
226 select CPU_CP15_MMU
227 select CPU_PABRT_LEGACY
228 select CPU_TLB_V4WBI if MMU
230 # ARM1022E
231 config CPU_ARM1022
232 bool "Support ARM1022E processor" if ARCH_INTEGRATOR
233 select CPU_32v5
234 select CPU_ABRT_EV4T
235 select CPU_CACHE_VIVT
236 select CPU_COPY_V4WB if MMU # can probably do better
237 select CPU_CP15_MMU
238 select CPU_PABRT_LEGACY
239 select CPU_TLB_V4WBI if MMU
240 help
241 The ARM1022E is an implementation of the ARMv5TE architecture
242 based upon the ARM10 integer core with a 16KiB L1 Harvard cache,
243 embedded trace macrocell, and a floating-point unit.
245 Say Y if you want support for the ARM1022E processor.
246 Otherwise, say N.
248 # ARM1026EJ-S
249 config CPU_ARM1026
250 bool "Support ARM1026EJ-S processor" if ARCH_INTEGRATOR
251 select CPU_32v5
252 select CPU_ABRT_EV5T # But need Jazelle, but EV5TJ ignores bit 10
253 select CPU_CACHE_VIVT
254 select CPU_COPY_V4WB if MMU # can probably do better
255 select CPU_CP15_MMU
256 select CPU_PABRT_LEGACY
257 select CPU_TLB_V4WBI if MMU
258 help
259 The ARM1026EJ-S is an implementation of the ARMv5TEJ architecture
260 based upon the ARM10 integer core.
262 Say Y if you want support for the ARM1026EJ-S processor.
263 Otherwise, say N.
265 # SA110
266 config CPU_SA110
267 bool
268 select CPU_32v3 if ARCH_RPC
269 select CPU_32v4 if !ARCH_RPC
270 select CPU_ABRT_EV4
271 select CPU_CACHE_V4WB
272 select CPU_CACHE_VIVT
273 select CPU_COPY_V4WB if MMU
274 select CPU_CP15_MMU
275 select CPU_PABRT_LEGACY
276 select CPU_TLB_V4WB if MMU
277 help
278 The Intel StrongARM(R) SA-110 is a 32-bit microprocessor and
279 is available at five speeds ranging from 100 MHz to 233 MHz.
280 More information is available at
281 <http://developer.intel.com/design/strong/sa110.htm>.
283 Say Y if you want support for the SA-110 processor.
284 Otherwise, say N.
286 # SA1100
287 config CPU_SA1100
288 bool
289 select CPU_32v4
290 select CPU_ABRT_EV4
291 select CPU_CACHE_V4WB
292 select CPU_CACHE_VIVT
293 select CPU_CP15_MMU
294 select CPU_PABRT_LEGACY
295 select CPU_TLB_V4WB if MMU
297 # XScale
298 config CPU_XSCALE
299 bool
300 select CPU_32v5
301 select CPU_ABRT_EV5T
302 select CPU_CACHE_VIVT
303 select CPU_CP15_MMU
304 select CPU_PABRT_LEGACY
305 select CPU_TLB_V4WBI if MMU
307 # XScale Core Version 3
308 config CPU_XSC3
309 bool
310 select CPU_32v5
311 select CPU_ABRT_EV5T
312 select CPU_CACHE_VIVT
313 select CPU_CP15_MMU
314 select CPU_PABRT_LEGACY
315 select CPU_TLB_V4WBI if MMU
316 select IO_36
318 # Marvell PJ1 (Mohawk)
319 config CPU_MOHAWK
320 bool
321 select CPU_32v5
322 select CPU_ABRT_EV5T
323 select CPU_CACHE_VIVT
324 select CPU_COPY_V4WB if MMU
325 select CPU_CP15_MMU
326 select CPU_PABRT_LEGACY
327 select CPU_TLB_V4WBI if MMU
329 # Feroceon
330 config CPU_FEROCEON
331 bool
332 select CPU_32v5
333 select CPU_ABRT_EV5T
334 select CPU_CACHE_VIVT
335 select CPU_COPY_FEROCEON if MMU
336 select CPU_CP15_MMU
337 select CPU_PABRT_LEGACY
338 select CPU_TLB_FEROCEON if MMU
340 config CPU_FEROCEON_OLD_ID
341 bool "Accept early Feroceon cores with an ARM926 ID"
342 depends on CPU_FEROCEON && !CPU_ARM926T
343 default y
344 help
345 This enables the usage of some old Feroceon cores
346 for which the CPU ID is equal to the ARM926 ID.
347 Relevant for Feroceon-1850 and early Feroceon-2850.
349 # Marvell PJ4
350 config CPU_PJ4
351 bool
352 select ARM_THUMBEE
353 select CPU_V7
355 config CPU_PJ4B
356 bool
357 select CPU_V7
359 # ARMv6
360 config CPU_V6
361 bool "Support ARM V6 processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB || MACH_REALVIEW_PBX
362 select CPU_32v6
363 select CPU_ABRT_EV6
364 select CPU_CACHE_V6
365 select CPU_CACHE_VIPT
366 select CPU_COPY_V6 if MMU
367 select CPU_CP15_MMU
368 select CPU_HAS_ASID if MMU
369 select CPU_PABRT_V6
370 select CPU_TLB_V6 if MMU
372 # ARMv6k
373 config CPU_V6K
374 bool "Support ARM V6K processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB || MACH_REALVIEW_PBX
375 select CPU_32v6
376 select CPU_32v6K
377 select CPU_ABRT_EV6
378 select CPU_CACHE_V6
379 select CPU_CACHE_VIPT
380 select CPU_COPY_V6 if MMU
381 select CPU_CP15_MMU
382 select CPU_HAS_ASID if MMU
383 select CPU_PABRT_V6
384 select CPU_TLB_V6 if MMU
386 # ARMv7
387 config CPU_V7
388 bool "Support ARM V7 processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB || MACH_REALVIEW_PBX
389 select CPU_32v6K
390 select CPU_32v7
391 select CPU_ABRT_EV7
392 select CPU_CACHE_V7
393 select CPU_CACHE_VIPT
394 select CPU_COPY_V6 if MMU
395 select CPU_CP15_MMU if MMU
396 select CPU_CP15_MPU if !MMU
397 select CPU_HAS_ASID if MMU
398 select CPU_PABRT_V7
399 select CPU_TLB_V7 if MMU
401 # ARMv7M
402 config CPU_V7M
403 bool
404 select CPU_32v7M
405 select CPU_ABRT_NOMMU
406 select CPU_CACHE_NOP
407 select CPU_PABRT_LEGACY
408 select CPU_THUMBONLY
410 config CPU_THUMBONLY
411 bool
412 # There are no CPUs available with MMU that don't implement an ARM ISA:
413 depends on !MMU
414 help
415 Select this if your CPU doesn't support the 32 bit ARM instructions.
417 # Figure out what processor architecture version we should be using.
418 # This defines the compiler instruction set which depends on the machine type.
419 config CPU_32v3
420 bool
421 select CPU_USE_DOMAINS if MMU
422 select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
423 select NEED_KUSER_HELPERS
424 select TLS_REG_EMUL if SMP || !MMU
426 config CPU_32v4
427 bool
428 select CPU_USE_DOMAINS if MMU
429 select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
430 select NEED_KUSER_HELPERS
431 select TLS_REG_EMUL if SMP || !MMU
433 config CPU_32v4T
434 bool
435 select CPU_USE_DOMAINS if MMU
436 select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
437 select NEED_KUSER_HELPERS
438 select TLS_REG_EMUL if SMP || !MMU
440 config CPU_32v5
441 bool
442 select CPU_USE_DOMAINS if MMU
443 select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
444 select NEED_KUSER_HELPERS
445 select TLS_REG_EMUL if SMP || !MMU
447 config CPU_32v6
448 bool
449 select TLS_REG_EMUL if !CPU_32v6K && !MMU
451 config CPU_32v6K
452 bool
454 config CPU_32v7
455 bool
457 config CPU_32v7M
458 bool
460 # The abort model
461 config CPU_ABRT_NOMMU
462 bool
464 config CPU_ABRT_EV4
465 bool
467 config CPU_ABRT_EV4T
468 bool
470 config CPU_ABRT_LV4T
471 bool
473 config CPU_ABRT_EV5T
474 bool
476 config CPU_ABRT_EV5TJ
477 bool
479 config CPU_ABRT_EV6
480 bool
482 config CPU_ABRT_EV7
483 bool
485 config CPU_PABRT_LEGACY
486 bool
488 config CPU_PABRT_V6
489 bool
491 config CPU_PABRT_V7
492 bool
494 # The cache model
495 config CPU_CACHE_V4
496 bool
498 config CPU_CACHE_V4WT
499 bool
501 config CPU_CACHE_V4WB
502 bool
504 config CPU_CACHE_V6
505 bool
507 config CPU_CACHE_V7
508 bool
510 config CPU_CACHE_NOP
511 bool
513 config CPU_CACHE_VIVT
514 bool
516 config CPU_CACHE_VIPT
517 bool
519 config CPU_CACHE_FA
520 bool
522 if MMU
523 # The copy-page model
524 config CPU_COPY_V4WT
525 bool
527 config CPU_COPY_V4WB
528 bool
530 config CPU_COPY_FEROCEON
531 bool
533 config CPU_COPY_FA
534 bool
536 config CPU_COPY_V6
537 bool
539 # This selects the TLB model
540 config CPU_TLB_V4WT
541 bool
542 help
543 ARM Architecture Version 4 TLB with writethrough cache.
545 config CPU_TLB_V4WB
546 bool
547 help
548 ARM Architecture Version 4 TLB with writeback cache.
550 config CPU_TLB_V4WBI
551 bool
552 help
553 ARM Architecture Version 4 TLB with writeback cache and invalidate
554 instruction cache entry.
556 config CPU_TLB_FEROCEON
557 bool
558 help
559 Feroceon TLB (v4wbi with non-outer-cachable page table walks).
561 config CPU_TLB_FA
562 bool
563 help
564 Faraday ARM FA526 architecture, unified TLB with writeback cache
565 and invalidate instruction cache entry. Branch target buffer is
566 also supported.
568 config CPU_TLB_V6
569 bool
571 config CPU_TLB_V7
572 bool
574 config VERIFY_PERMISSION_FAULT
575 bool
576 endif
578 config CPU_HAS_ASID
579 bool
580 help
581 This indicates whether the CPU has the ASID register; used to
582 tag TLB and possibly cache entries.
584 config CPU_CP15
585 bool
586 help
587 Processor has the CP15 register.
589 config CPU_CP15_MMU
590 bool
591 select CPU_CP15
592 help
593 Processor has the CP15 register, which has MMU related registers.
595 config CPU_CP15_MPU
596 bool
597 select CPU_CP15
598 help
599 Processor has the CP15 register, which has MPU related registers.
601 config CPU_USE_DOMAINS
602 bool
603 help
604 This option enables or disables the use of domain switching
605 via the set_fs() function.
607 #
608 # CPU supports 36-bit I/O
609 #
610 config IO_36
611 bool
613 comment "Processor Features"
615 config ARM_LPAE
616 bool "Support for the Large Physical Address Extension"
617 depends on MMU && CPU_32v7 && !CPU_32v6 && !CPU_32v5 && \
618 !CPU_32v4 && !CPU_32v3
619 help
620 Say Y if you have an ARMv7 processor supporting the LPAE page
621 table format and you would like to access memory beyond the
622 4GB limit. The resulting kernel image will not run on
623 processors without the LPA extension.
625 If unsure, say N.
627 config ARCH_PHYS_ADDR_T_64BIT
628 def_bool ARM_LPAE
630 config ARCH_DMA_ADDR_T_64BIT
631 bool
633 config ARM_THUMB
634 bool "Support Thumb user binaries" if !CPU_THUMBONLY
635 depends on CPU_ARM720T || CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || \
636 CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || \
637 CPU_ARM1020 || CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
638 CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_V6 || CPU_V6K || \
639 CPU_V7 || CPU_FEROCEON || CPU_V7M
640 default y
641 help
642 Say Y if you want to include kernel support for running user space
643 Thumb binaries.
645 The Thumb instruction set is a compressed form of the standard ARM
646 instruction set resulting in smaller binaries at the expense of
647 slightly less efficient code.
649 If you don't know what this all is, saying Y is a safe choice.
651 config ARM_THUMBEE
652 bool "Enable ThumbEE CPU extension"
653 depends on CPU_V7
654 help
655 Say Y here if you have a CPU with the ThumbEE extension and code to
656 make use of it. Say N for code that can run on CPUs without ThumbEE.
658 config ARM_VIRT_EXT
659 bool
660 depends on MMU
661 default y if CPU_V7
662 help
663 Enable the kernel to make use of the ARM Virtualization
664 Extensions to install hypervisors without run-time firmware
665 assistance.
667 A compliant bootloader is required in order to make maximum
668 use of this feature. Refer to Documentation/arm/Booting for
669 details.
671 config SWP_EMULATE
672 bool "Emulate SWP/SWPB instructions"
673 depends on CPU_V7
674 default y if SMP
675 select HAVE_PROC_CPU if PROC_FS
676 help
677 ARMv6 architecture deprecates use of the SWP/SWPB instructions.
678 ARMv7 multiprocessing extensions introduce the ability to disable
679 these instructions, triggering an undefined instruction exception
680 when executed. Say Y here to enable software emulation of these
681 instructions for userspace (not kernel) using LDREX/STREX.
682 Also creates /proc/cpu/swp_emulation for statistics.
684 In some older versions of glibc [<=2.8] SWP is used during futex
685 trylock() operations with the assumption that the code will not
686 be preempted. This invalid assumption may be more likely to fail
687 with SWP emulation enabled, leading to deadlock of the user
688 application.
690 NOTE: when accessing uncached shared regions, LDREX/STREX rely
691 on an external transaction monitoring block called a global
692 monitor to maintain update atomicity. If your system does not
693 implement a global monitor, this option can cause programs that
694 perform SWP operations to uncached memory to deadlock.
696 If unsure, say Y.
698 config CPU_BIG_ENDIAN
699 bool "Build big-endian kernel"
700 depends on ARCH_SUPPORTS_BIG_ENDIAN
701 help
702 Say Y if you plan on running a kernel in big-endian mode.
703 Note that your board must be properly built and your board
704 port must properly enable any big-endian related features
705 of your chipset/board/processor.
707 config CPU_ENDIAN_BE8
708 bool
709 depends on CPU_BIG_ENDIAN
710 default CPU_V6 || CPU_V6K || CPU_V7
711 help
712 Support for the BE-8 (big-endian) mode on ARMv6 and ARMv7 processors.
714 config CPU_ENDIAN_BE32
715 bool
716 depends on CPU_BIG_ENDIAN
717 default !CPU_ENDIAN_BE8
718 help
719 Support for the BE-32 (big-endian) mode on pre-ARMv6 processors.
721 config CPU_HIGH_VECTOR
722 depends on !MMU && CPU_CP15 && !CPU_ARM740T
723 bool "Select the High exception vector"
724 help
725 Say Y here to select high exception vector(0xFFFF0000~).
726 The exception vector can vary depending on the platform
727 design in nommu mode. If your platform needs to select
728 high exception vector, say Y.
729 Otherwise or if you are unsure, say N, and the low exception
730 vector (0x00000000~) will be used.
732 config CPU_ICACHE_DISABLE
733 bool "Disable I-Cache (I-bit)"
734 depends on CPU_CP15 && !(CPU_ARM720T || CPU_ARM740T || CPU_XSCALE || CPU_XSC3)
735 help
736 Say Y here to disable the processor instruction cache. Unless
737 you have a reason not to or are unsure, say N.
739 config CPU_DCACHE_DISABLE
740 bool "Disable D-Cache (C-bit)"
741 depends on CPU_CP15
742 help
743 Say Y here to disable the processor data cache. Unless
744 you have a reason not to or are unsure, say N.
746 config CPU_DCACHE_SIZE
747 hex
748 depends on CPU_ARM740T || CPU_ARM946E
749 default 0x00001000 if CPU_ARM740T
750 default 0x00002000 # default size for ARM946E-S
751 help
752 Some cores are synthesizable to have various sized cache. For
753 ARM946E-S case, it can vary from 0KB to 1MB.
754 To support such cache operations, it is efficient to know the size
755 before compile time.
756 If your SoC is configured to have a different size, define the value
757 here with proper conditions.
759 config CPU_DCACHE_WRITETHROUGH
760 bool "Force write through D-cache"
761 depends on (CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || CPU_ARM1020 || CPU_FA526) && !CPU_DCACHE_DISABLE
762 default y if CPU_ARM925T
763 help
764 Say Y here to use the data cache in writethrough mode. Unless you
765 specifically require this or are unsure, say N.
767 config CPU_CACHE_ROUND_ROBIN
768 bool "Round robin I and D cache replacement algorithm"
769 depends on (CPU_ARM926T || CPU_ARM946E || CPU_ARM1020) && (!CPU_ICACHE_DISABLE || !CPU_DCACHE_DISABLE)
770 help
771 Say Y here to use the predictable round-robin cache replacement
772 policy. Unless you specifically require this or are unsure, say N.
774 config CPU_BPREDICT_DISABLE
775 bool "Disable branch prediction"
776 depends on CPU_ARM1020 || CPU_V6 || CPU_V6K || CPU_MOHAWK || CPU_XSC3 || CPU_V7 || CPU_FA526
777 help
778 Say Y here to disable branch prediction. If unsure, say N.
780 config TLS_REG_EMUL
781 bool
782 select NEED_KUSER_HELPERS
783 help
784 An SMP system using a pre-ARMv6 processor (there are apparently
785 a few prototypes like that in existence) and therefore access to
786 that required register must be emulated.
788 config NEEDS_SYSCALL_FOR_CMPXCHG
789 bool
790 select NEED_KUSER_HELPERS
791 help
792 SMP on a pre-ARMv6 processor? Well OK then.
793 Forget about fast user space cmpxchg support.
794 It is just not possible.
796 config NEED_KUSER_HELPERS
797 bool
799 config KUSER_HELPERS
800 bool "Enable kuser helpers in vector page" if !NEED_KUSER_HELPERS
801 default y
802 help
803 Warning: disabling this option may break user programs.
805 Provide kuser helpers in the vector page. The kernel provides
806 helper code to userspace in read only form at a fixed location
807 in the high vector page to allow userspace to be independent of
808 the CPU type fitted to the system. This permits binaries to be
809 run on ARMv4 through to ARMv7 without modification.
811 See Documentation/arm/kernel_user_helpers.txt for details.
813 However, the fixed address nature of these helpers can be used
814 by ROP (return orientated programming) authors when creating
815 exploits.
817 If all of the binaries and libraries which run on your platform
818 are built specifically for your platform, and make no use of
819 these helpers, then you can turn this option off to hinder
820 such exploits. However, in that case, if a binary or library
821 relying on those helpers is run, it will receive a SIGILL signal,
822 which will terminate the program.
824 Say N here only if you are absolutely certain that you do not
825 need these helpers; otherwise, the safe option is to say Y.
827 config DMA_CACHE_RWFO
828 bool "Enable read/write for ownership DMA cache maintenance"
829 depends on CPU_V6K && SMP
830 default y
831 help
832 The Snoop Control Unit on ARM11MPCore does not detect the
833 cache maintenance operations and the dma_{map,unmap}_area()
834 functions may leave stale cache entries on other CPUs. By
835 enabling this option, Read or Write For Ownership in the ARMv6
836 DMA cache maintenance functions is performed. These LDR/STR
837 instructions change the cache line state to shared or modified
838 so that the cache operation has the desired effect.
840 Note that the workaround is only valid on processors that do
841 not perform speculative loads into the D-cache. For such
842 processors, if cache maintenance operations are not broadcast
843 in hardware, other workarounds are needed (e.g. cache
844 maintenance broadcasting in software via FIQ).
846 config OUTER_CACHE
847 bool
849 config OUTER_CACHE_SYNC
850 bool
851 help
852 The outer cache has a outer_cache_fns.sync function pointer
853 that can be used to drain the write buffer of the outer cache.
855 config CACHE_FEROCEON_L2
856 bool "Enable the Feroceon L2 cache controller"
857 depends on ARCH_KIRKWOOD || ARCH_MV78XX0 || ARCH_MVEBU
858 default y
859 select OUTER_CACHE
860 help
861 This option enables the Feroceon L2 cache controller.
863 config CACHE_FEROCEON_L2_WRITETHROUGH
864 bool "Force Feroceon L2 cache write through"
865 depends on CACHE_FEROCEON_L2
866 help
867 Say Y here to use the Feroceon L2 cache in writethrough mode.
868 Unless you specifically require this, say N for writeback mode.
870 config MIGHT_HAVE_CACHE_L2X0
871 bool
872 help
873 This option should be selected by machines which have a L2x0
874 or PL310 cache controller, but where its use is optional.
876 The only effect of this option is to make CACHE_L2X0 and
877 related options available to the user for configuration.
879 Boards or SoCs which always require the cache controller
880 support to be present should select CACHE_L2X0 directly
881 instead of this option, thus preventing the user from
882 inadvertently configuring a broken kernel.
884 config CACHE_L2X0
885 bool "Enable the L2x0 outer cache controller" if MIGHT_HAVE_CACHE_L2X0
886 default MIGHT_HAVE_CACHE_L2X0
887 select OUTER_CACHE
888 select OUTER_CACHE_SYNC
889 help
890 This option enables the L2x0 PrimeCell.
892 config CACHE_PL310
893 bool
894 depends on CACHE_L2X0
895 default y if CPU_V7 && !(CPU_V6 || CPU_V6K)
896 help
897 This option enables optimisations for the PL310 cache
898 controller.
900 config PL310_ERRATA_588369
901 bool "PL310 errata: Clean & Invalidate maintenance operations do not invalidate clean lines"
902 depends on CACHE_L2X0
903 help
904 The PL310 L2 cache controller implements three types of Clean &
905 Invalidate maintenance operations: by Physical Address
906 (offset 0x7F0), by Index/Way (0x7F8) and by Way (0x7FC).
907 They are architecturally defined to behave as the execution of a
908 clean operation followed immediately by an invalidate operation,
909 both performing to the same memory location. This functionality
910 is not correctly implemented in PL310 as clean lines are not
911 invalidated as a result of these operations.
913 config PL310_ERRATA_727915
914 bool "PL310 errata: Background Clean & Invalidate by Way operation can cause data corruption"
915 depends on CACHE_L2X0
916 help
917 PL310 implements the Clean & Invalidate by Way L2 cache maintenance
918 operation (offset 0x7FC). This operation runs in background so that
919 PL310 can handle normal accesses while it is in progress. Under very
920 rare circumstances, due to this erratum, write data can be lost when
921 PL310 treats a cacheable write transaction during a Clean &
922 Invalidate by Way operation.
924 config PL310_ERRATA_753970
925 bool "PL310 errata: cache sync operation may be faulty"
926 depends on CACHE_PL310
927 help
928 This option enables the workaround for the 753970 PL310 (r3p0) erratum.
930 Under some condition the effect of cache sync operation on
931 the store buffer still remains when the operation completes.
932 This means that the store buffer is always asked to drain and
933 this prevents it from merging any further writes. The workaround
934 is to replace the normal offset of cache sync operation (0x730)
935 by another offset targeting an unmapped PL310 register 0x740.
936 This has the same effect as the cache sync operation: store buffer
937 drain and waiting for all buffers empty.
939 config PL310_ERRATA_769419
940 bool "PL310 errata: no automatic Store Buffer drain"
941 depends on CACHE_L2X0
942 help
943 On revisions of the PL310 prior to r3p2, the Store Buffer does
944 not automatically drain. This can cause normal, non-cacheable
945 writes to be retained when the memory system is idle, leading
946 to suboptimal I/O performance for drivers using coherent DMA.
947 This option adds a write barrier to the cpu_idle loop so that,
948 on systems with an outer cache, the store buffer is drained
949 explicitly.
951 config CACHE_TAUROS2
952 bool "Enable the Tauros2 L2 cache controller"
953 depends on (ARCH_DOVE || ARCH_MMP || CPU_PJ4)
954 default y
955 select OUTER_CACHE
956 help
957 This option enables the Tauros2 L2 cache controller (as
958 found on PJ1/PJ4).
960 config CACHE_XSC3L2
961 bool "Enable the L2 cache on XScale3"
962 depends on CPU_XSC3
963 default y
964 select OUTER_CACHE
965 help
966 This option enables the L2 cache on XScale3.
968 config ARM_L1_CACHE_SHIFT_6
969 bool
970 default y if CPU_V7
971 help
972 Setting ARM L1 cache line size to 64 Bytes.
974 config ARM_L1_CACHE_SHIFT
975 int
976 default 6 if ARM_L1_CACHE_SHIFT_6
977 default 5
979 config ARM_DMA_MEM_BUFFERABLE
980 bool "Use non-cacheable memory for DMA" if (CPU_V6 || CPU_V6K) && !CPU_V7
981 depends on !(MACH_REALVIEW_PB1176 || REALVIEW_EB_ARM11MP || \
982 MACH_REALVIEW_PB11MP)
983 default y if CPU_V6 || CPU_V6K || CPU_V7
984 help
985 Historically, the kernel has used strongly ordered mappings to
986 provide DMA coherent memory. With the advent of ARMv7, mapping
987 memory with differing types results in unpredictable behaviour,
988 so on these CPUs, this option is forced on.
990 Multiple mappings with differing attributes is also unpredictable
991 on ARMv6 CPUs, but since they do not have aggressive speculative
992 prefetch, no harm appears to occur.
994 However, drivers may be missing the necessary barriers for ARMv6,
995 and therefore turning this on may result in unpredictable driver
996 behaviour. Therefore, we offer this as an option.
998 You are recommended say 'Y' here and debug any affected drivers.
1000 config ARCH_HAS_BARRIERS
1001 bool
1002 help
1003 This option allows the use of custom mandatory barriers
1004 included via the mach/barriers.h file.
1006 config ARCH_SUPPORTS_BIG_ENDIAN
1007 bool
1008 help
1009 This option specifies the architecture can support big endian
1010 operation.