ARC: Unaligned access emulation

[linux-2.6-block.git] / arch / arc / Kconfig

#
# Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.
#

config ARC
	def_bool y
	select ARCH_NO_VIRT_TO_BUS
	select CLONE_BACKWARDS
	# ARC Busybox based initramfs absolutely relies on DEVTMPFS for /dev
	select DEVTMPFS if !INITRAMFS_SOURCE=""
	select GENERIC_ATOMIC64
	select GENERIC_CLOCKEVENTS
	select GENERIC_FIND_FIRST_BIT
	# for now, we don't need GENERIC_IRQ_PROBE, CONFIG_GENERIC_IRQ_CHIP
	select GENERIC_IRQ_SHOW
	select GENERIC_KERNEL_EXECVE
	select GENERIC_KERNEL_THREAD
	select GENERIC_PENDING_IRQ if SMP
	select GENERIC_SIGALTSTACK
	select GENERIC_SMP_IDLE_THREAD
	select HAVE_ARCH_TRACEHOOK
	select HAVE_GENERIC_HARDIRQS
	select HAVE_KPROBES
	select HAVE_KRETPROBES
	select HAVE_MEMBLOCK
	select HAVE_MOD_ARCH_SPECIFIC if ARC_DW2_UNWIND
	select HAVE_OPROFILE
	select IRQ_DOMAIN
	select MODULES_USE_ELF_RELA
	select NO_BOOTMEM
	select OF
	select OF_EARLY_FLATTREE

config SCHED_OMIT_FRAME_POINTER
	def_bool y

config GENERIC_CSUM
	def_bool y

config RWSEM_GENERIC_SPINLOCK
	def_bool y

config ARCH_FLATMEM_ENABLE
	def_bool y

config MMU
	def_bool y

config NO_IOPORT
	def_bool y

config GENERIC_CALIBRATE_DELAY
	def_bool y

config GENERIC_HWEIGHT
	def_bool y

config BINFMT_ELF
	def_bool y

config STACKTRACE_SUPPORT
	def_bool y
	select STACKTRACE

config HAVE_LATENCYTOP_SUPPORT
	def_bool y

config NO_DMA
	def_bool n

source "init/Kconfig"
source "kernel/Kconfig.freezer"

menu "ARC Architecture Configuration"

choice
	prompt "ARC Platform"
	default ARC_PLAT_FPGA_LEGACY

config ARC_PLAT_FPGA_LEGACY
	bool "\"Legacy\" ARC FPGA dev platform"
	help
	  Support for ARC development platforms, provided by Synopsys.
	  These are based on FPGA or ISS. e.g.
	  - ARCAngel4
	  - ML509
	  - MetaWare ISS

#New platform adds here
endchoice

menu "ARC CPU Configuration"

choice
	prompt "ARC Core"
	default ARC_CPU_770

config ARC_CPU_750D
	bool "ARC750D"
	help
	  Support for ARC750 core

config ARC_CPU_770
	bool "ARC770"
	select ARC_CPU_REL_4_10
	help
	  Support for ARC770 core introduced with Rel 4.10 (Summer 2011)
	  This core has a bunch of cool new features:
	  -MMU-v3: Variable Page Sz (4k, 8k, 16k), bigger J-TLB (128x4)
                   Shared Address Spaces (for sharing TLB entires in MMU)
	  -Caches: New Prog Model, Region Flush
	  -Insns: endian swap, load-locked/store-conditional, time-stamp-ctr

endchoice

config CPU_BIG_ENDIAN
	bool "Enable Big Endian Mode"
	default n
	help
	  Build kernel for Big Endian Mode of ARC CPU

config SMP
	bool "Symmetric Multi-Processing (Incomplete)"
	default n
	select USE_GENERIC_SMP_HELPERS
	help
	  This enables support for systems with more than one CPU. If you have
	  a system with only one CPU, like most personal computers, say N. If
	  you have a system with more than one CPU, say Y.

if SMP

config ARC_HAS_COH_CACHES
	def_bool n

config ARC_HAS_COH_LLSC
	def_bool n

config ARC_HAS_COH_RTSC
	def_bool n

config ARC_HAS_REENTRANT_IRQ_LV2
	def_bool n

endif

config NR_CPUS
	int "Maximum number of CPUs (2-32)"
	range 2 32
	depends on SMP
	default "2"

menuconfig ARC_CACHE
	bool "Enable Cache Support"
	default y
	# if SMP, cache enabled ONLY if ARC implementation has cache coherency
	depends on !SMP || ARC_HAS_COH_CACHES

if ARC_CACHE

config ARC_CACHE_LINE_SHIFT
	int "Cache Line Length (as power of 2)"
	range 5 7
	default "6"
	help
	  Starting with ARC700 4.9, Cache line length is configurable,
	  This option specifies "N", with Line-len = 2 power N
	  So line lengths of 32, 64, 128 are specified by 5,6,7, respectively
	  Linux only supports same line lengths for I and D caches.

config ARC_HAS_ICACHE
	bool "Use Instruction Cache"
	default y

config ARC_HAS_DCACHE
	bool "Use Data Cache"
	default y

config ARC_CACHE_PAGES
	bool "Per Page Cache Control"
	default y
	depends on ARC_HAS_ICACHE || ARC_HAS_DCACHE
	help
	  This can be used to over-ride the global I/D Cache Enable on a
	  per-page basis (but only for pages accessed via MMU such as
	  Kernel Virtual address or User Virtual Address)
	  TLB entries have a per-page Cache Enable Bit.
	  Note that Global I/D ENABLE + Per Page DISABLE works but corollary
	  Global DISABLE + Per Page ENABLE won't work

endif	#ARC_CACHE

config ARC_HAS_HW_MPY
	bool "Use Hardware Multiplier (Normal or Faster XMAC)"
	default y
	help
	  Influences how gcc generates code for MPY operations.
	  If enabled, MPYxx insns are generated, provided by Standard/XMAC
	  Multipler. Otherwise software multipy lib is used

choice
	prompt "ARC700 MMU Version"
	default ARC_MMU_V3 if ARC_CPU_770
	default ARC_MMU_V2 if ARC_CPU_750D

config ARC_MMU_V1
	bool "MMU v1"
	help
	  Orig ARC700 MMU

config ARC_MMU_V2
	bool "MMU v2"
	help
	  Fixed the deficiency of v1 - possible thrashing in memcpy sceanrio
	  when 2 D-TLB and 1 I-TLB entries index into same 2way set.

config ARC_MMU_V3
	bool "MMU v3"
	depends on ARC_CPU_770
	help
	  Introduced with ARC700 4.10: New Features
	  Variable Page size (1k-16k), var JTLB size 128 x (2 or 4)
	  Shared Address Spaces (SASID)

endchoice


choice
	prompt "MMU Page Size"
	default ARC_PAGE_SIZE_8K

config ARC_PAGE_SIZE_8K
	bool "8KB"
	help
	  Choose between 8k vs 16k

config ARC_PAGE_SIZE_16K
	bool "16KB"
	depends on ARC_MMU_V3

config ARC_PAGE_SIZE_4K
	bool "4KB"
	depends on ARC_MMU_V3

endchoice

config ARC_COMPACT_IRQ_LEVELS
	bool "ARCompact IRQ Priorities: High(2)/Low(1)"
	default n
	# Timer HAS to be high priority, for any other high priority config
	select ARC_IRQ3_LV2
	# if SMP, LV2 enabled ONLY if ARC implementation has LV2 re-entrancy
	depends on !SMP || ARC_HAS_REENTRANT_IRQ_LV2

if ARC_COMPACT_IRQ_LEVELS

config ARC_IRQ3_LV2
	bool

config ARC_IRQ5_LV2
	bool

config ARC_IRQ6_LV2
	bool

endif

config ARC_FPU_SAVE_RESTORE
	bool "Enable FPU state persistence across context switch"
	default n
	help
	  Double Precision Floating Point unit had dedictaed regs which
	  need to be saved/restored across context-switch.
	  Note that ARC FPU is overly simplistic, unlike say x86, which has
	  hardware pieces to allow software to conditionally save/restore,
	  based on actual usage of FPU by a task. Thus our implemn does
	  this for all tasks in system.

menuconfig ARC_CPU_REL_4_10
	bool "Enable support for Rel 4.10 features"
	default n
	help
	  -ARC770 (and dependent features) enabled
	  -ARC750 also shares some of the new features with 770

config ARC_HAS_LLSC
	bool "Insn: LLOCK/SCOND (efficient atomic ops)"
	default y
	depends on ARC_CPU_770
	# if SMP, enable LLSC ONLY if ARC implementation has coherent atomics
	depends on !SMP || ARC_HAS_COH_LLSC

config ARC_HAS_SWAPE
	bool "Insn: SWAPE (endian-swap)"
	default y
	depends on ARC_CPU_REL_4_10

config ARC_HAS_RTSC
	bool "Insn: RTSC (64-bit r/o cycle counter)"
	default y
	depends on ARC_CPU_REL_4_10
	# if SMP, enable RTSC only if counter is coherent across cores
	depends on !SMP || ARC_HAS_COH_RTSC

endmenu   # "ARC CPU Configuration"

menu "Platform Board Configuration"

source "arch/arc/plat-arcfpga/Kconfig"

#New platform adds here

config LINUX_LINK_BASE
	hex "Linux Link Address"
	default "0x80000000"
	help
	  ARC700 divides the 32 bit phy address space into two equal halves
	  -Lower 2G (0 - 0x7FFF_FFFF ) is user virtual, translated by MMU
	  -Upper 2G (0x8000_0000 onwards) is untranslated, for kernel
	  Typically Linux kernel is linked at the start of untransalted addr,
	  hence the default value of 0x8zs.
	  However some customers have peripherals mapped at this addr, so
	  Linux needs to be scooted a bit.
	  If you don't know what the above means, leave this setting alone.

endmenu # "Platform Board Configuration"

config ARC_CURR_IN_REG
	bool "Dedicate Register r25 for current_task pointer"
	default y
	help
	  This reserved Register R25 to point to Current Task in
	  kernel mode. This saves memory access for each such access


config ARC_MISALIGN_ACCESS
	bool "Emulate unaligned memory access (userspace only)"
	default N
	select SYSCTL_ARCH_UNALIGN_NO_WARN
	select SYSCTL_ARCH_UNALIGN_ALLOW
	help
	  This enables misaligned 16 & 32 bit memory access from user space.
	  Use ONLY-IF-ABS-NECESSARY as it will be very slow and also can hide
	  potential bugs in code

config ARC_STACK_NONEXEC
	bool "Make stack non-executable"
	default n
	help
	  To disable the execute permissions of stack/heap of processes
	  which are enabled by default.

config HZ
	int "Timer Frequency"
	default 100

menuconfig ARC_DBG
	bool "ARC debugging"
	default y

config ARC_DW2_UNWIND
	bool "Enable DWARF specific kernel stack unwind"
	depends on ARC_DBG
	default y
	select KALLSYMS
	help
	  Compiles the kernel with DWARF unwind information and can be used
	  to get stack backtraces.

	  If you say Y here the resulting kernel image will be slightly larger
	  but not slower, and it will give very useful debugging information.
	  If you don't debug the kernel, you can say N, but we may not be able
	  to solve problems without frame unwind information

config ARC_DBG_TLB_PARANOIA
	bool "Paranoia Checks in Low Level TLB Handlers"
	depends on ARC_DBG && !SMP
	default n

config ARC_DBG_TLB_MISS_COUNT
	bool "Profile TLB Misses"
	default n
	select DEBUG_FS
	depends on ARC_DBG
	help
	  Counts number of I and D TLB Misses and exports them via Debugfs
	  The counters can be cleared via Debugfs as well

config CMDLINE
	string "Kernel command line to built-in"
	default "print-fatal-signals=1"
	help
	  The default command line which will be appended to the optional
	  u-boot provided command line (see below)

config CMDLINE_UBOOT
	bool "Support U-boot kernel command line passing"
	default n
	help
	  If you are using U-boot (www.denx.de) and wish to pass the kernel
	  command line from the U-boot environment to the Linux kernel then
	  switch this option on.
	  ARC U-boot will setup the cmdline in RAM/flash and set r2 to point
	  to it. kernel startup code will copy the string into cmdline buffer
	  and also append CONFIG_CMDLINE.

config ARC_BUILTIN_DTB_NAME
	string "Built in DTB"
	help
	  Set the name of the DTB to embed in the vmlinux binary
	  Leaving it blank selects the minimal "skeleton" dtb

source "kernel/Kconfig.preempt"

endmenu	 # "ARC Architecture Configuration"

source "mm/Kconfig"
source "net/Kconfig"
source "drivers/Kconfig"
source "fs/Kconfig"
source "arch/arc/Kconfig.debug"
source "security/Kconfig"
source "crypto/Kconfig"
source "lib/Kconfig"