linux/arch/arc/Kconfig
Vineet Gupta 41195d236e ARC: SMP support
ARC common code to enable a SMP system + ISS provided SMP extensions.

ARC700 natively lacks SMP support, hence some of the core features are
are only enabled if SoCs have the necessary h/w pixie-dust. This
includes:
-Inter Processor Interrupts (IPI)
-Cache coherency
-load-locked/store-conditional
...

The low level exception handling would be completely broken in SMP
because we don't have hardware assisted stack switching. Thus a fair bit
of this code is repurposing the MMU_SCRATCH reg for event handler
prologues to keep them re-entrant.

Many thanks to Rajeshwar Ranga for his initial "major" contributions to
SMP Port (back in 2008), and to Noam Camus and Gilad Ben-Yossef for help
with resurrecting that in 3.2 kernel (2012).

Note that this platform code is again singleton design pattern - so
multiple SMP platforms won't build at the moment - this deficiency is
addressed in subsequent patches within this series.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rajeshwar Ranga <rajeshwar.ranga@gmail.com>
Cc: Noam Camus <noamc@ezchip.com>
Cc: Gilad Ben-Yossef <gilad@benyossef.com>
2013-02-15 23:16:02 +05:30

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#
# 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_MEMBLOCK
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 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_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_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"