This is to workaround the llock/scond livelock
HS38x4 could get into a LLOCK/SCOND livelock in case of multiple overlapping
coherency transactions in the SCU. The exclusive line state keeps rotating
among contenting cores leading to a never ending cycle. So break the cycle
by deferring the retry of failed exclusive access (SCOND). The actual delay
needed is function of number of contending cores as well as the unrelated
coherency traffic from other cores. To keep the code simple, start off with
small delay of 1 which would suffice most cases and in case of contention
double the delay. Eventually the delay is sufficient such that the coherency
pipeline is drained, thus a subsequent exclusive access would succeed.
Link: http://lkml.kernel.org/r/1438612568-28265-1-git-send-email-vgupta@synopsys.com
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Being highly configurable core ARC HS among other features might be
configured with or without DIV_REM_OPTION (hardware divider).
That option when enabled adds following instructions: div, divu, rem, remu.
By default ARC HS38 has this option enabled. So we add here possibility
to disable usage of hardware divider by compiler.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Caveats about cache flush on ARCv2 based cores
- dcache is PIPT so paddr is sufficient for cache maintenance ops (no
need to setup PTAG reg
- icache is still VIPT but only aliasing configs need PTAG setup
So basically this is departure from MMU-v3 which always need vaddr in
line ops registers (DC_IVDL, DC_FLDL, IC_IVIL) but paddr in DC_PTAG,
IC_PTAG respectively.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The AXS10x platforms consist of a mainboard with peripherals,
on which several daughter cards can be placed. The daughter cards
typically contain a CPU and memory.
Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* Remove remanants of legacy ARC FPGA platforms (AA4, ML509...)
* Only nsim simulation platform is left, rename platform accordingly
* AA4 DT stuff is compatible with nsim for ARC700 so rename it too
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Back when ARC700 4.10 was released, the related kernel features were
tied to this config item so they could be disabled in one shot (i.e.
LLOCK/SCOND, SWAPE, RTSC..)
That having happened a while back, all new ARC customers weill get 4.11+
so those features can be assumed to be present and need not be tied to a
top-level (we still retain the ability to individually disable them).
Further, since ARCv2 also shares some of those feautes, removing it
simplifies things a bit in Kconfig
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Even though ARC cores itself don't have any power management except SLEEP
state it's possible to use power management features of selected peripherals.
For example USB OTG requires PM_RUNTIME which is only available if
kernel/power/Kconfig is sourced by architecture.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Architectures only need a Kconfig entry for NO_DMA if it is possible
that its value will be 'y'. For arc its value will always be 'n', making
it pointless. Remove it.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
All the platforms do the same thing in init_machine callback so move it
out of callback into caller of callback
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
If the renamed symbol is defined lib/iomap.c implements ioport_map and
ioport_unmap and currently (nearly) all platforms define the port
accessor functions outb/inb and friend unconditionally. So
HAS_IOPORT_MAP is the better name for this.
Consequently NO_IOPORT is renamed to NO_IOPORT_MAP.
The motivation for this change is to reintroduce a symbol HAS_IOPORT
that signals if outb/int et al are available. I will address that at
least one merge window later though to keep surprises to a minimum and
catch new introductions of (HAS|NO)_IOPORT.
The changes in this commit were done using:
$ git grep -l -E '(NO|HAS)_IOPORT' | xargs perl -p -i -e 's/\b((?:CONFIG_)?(?:NO|HAS)_IOPORT)\b/$1_MAP/'
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A number of Kconfig entries default to (uppercase) "N". It was clearly
intended to use "default n". But since (lowercase) "n" is the default
anyway, these lines might as well be removed.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Remove an outdated reference to "most personal computers" having only one
CPU, and change the use of "singleprocessor" and "single processor" in
CONFIG_SMP's documentation to "uniprocessor" across all arches where that
documentation is present.
Signed-off-by: Robert Graffham <psquid@psquid.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Moved cmdline copy from asm to "C" - allows for more robust checking
of pointer validity etc.
* Remove the Kconfig option to do so, base it on a runtime value passed
by u-boot
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
We've switched over every architecture that supports SMP to it, so
remove the new useless config variable.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lockdep required a small fix to stacktrace API which was incorrectly
unwindign out of __switch_to for the current call frame.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
After the last architecture switched to generic hard irqs the config
options HAVE_GENERIC_HARDIRQS & GENERIC_HARDIRQS and the related code
for !CONFIG_GENERIC_HARDIRQS can be removed.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Merge Kconfig menu diet patches from Dave Hansen:
"I think the "Kernel Hacking" menu has gotten a bit out of hand. It is
over 120 lines long on my system with everything enabled and options
are scattered around it haphazardly.
http://sr71.net/~dave/linux/kconfig-horror.png
Let's try to introduce some sanity. This set takes that 120 lines
down to 55 and makes it vastly easier to find some things. It's a
start.
This set stands on its own, but there is plenty of room for follow-up
patches. The arch-specific debug options still end up getting stuck
in the top-level "kernel hacking" menu. OPTIMIZE_INLINING, for
instance, could obviously go in to the "compiler options" menu, but
the fact that it is defined in arch/ in a separate Kconfig file keeps
it on its own for the moment.
The Signed-off-by's in here look funky. I changed employers while
working on this set, so I have signoffs from both email addresses"
* emailed patches from Dave Hansen <dave@sr71.net>:
hang and lockup detection menu
kconfig: consolidate printk options
group locking debugging options
consolidate compilation option configs
consolidate runtime testing configs
order memory debugging Kconfig options
consolidate per-arch stack overflow debugging options
Original posting:
http://lkml.kernel.org/r/20121214184202.F54094D9@kernel.stglabs.ibm.com
Several architectures have similar stack debugging config options.
They all pretty much do the same thing, some with slightly
differing help text.
This patch changes the architectures to instead enable a Kconfig
boolean, and then use that boolean in the generic Kconfig.debug
to present the actual menu option. This removes a bunch of
duplication and adds consistency across arches.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com> [for tile]
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1. For VM_EXEC based delayed dcache/icache flush, reduces the number of
flushes.
2. Makes this security feature ON by default rather than OFF before.
3. Applications can use mprotect() to selectively override this.
4. ELF binaries have a GNU_STACK segment which can easily override the
kernel default permissions.
For nested-functions/trampolines, gcc already auto-enables executable
stack in elf. Others needing this can use -Wl,-z,execstack option.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This is the meat of the series which prevents any dcache alias creation
by always keeping the U and K mapping of a page congruent.
If a mapping already exists, and other tries to access the page, prev
one is flushed to physical page (wback+inv)
Essentially flush_dcache_page()/copy_user_highpage() create K-mapping
of a page, but try to defer flushing, unless U-mapping exist.
When page is actually mapped to userspace, update_mmu_cache() flushes
the K-mapping (in certain cases this can be optimised out)
Additonally flush_cache_mm(), flush_cache_range(), flush_cache_page()
handle the puring of stale userspace mappings on exit/munmap...
flush_anon_page() handles the existing U-mapping for anon page before
kernel reads it via the GUP path.
Note that while not complete, this is enough to boot a simple
dynamically linked Busybox based rootfs
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Infrastructure required to make the Linux kernel compile and boot on the
Abilis Systems TB10x series of SOCs based on ARC700 CPUs:
- Kmake related files (Kconfig, Makefile, tb10x_defconfig)
- TB10x platform initialisation
Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Given that DeviceTree /bootargs can provide similar functionality,
no point in providing duplicate infrastructure.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This tracks mainline commit ae903caae2 "Bury the conditionals from
kernel_thread/kernel_execve series" which we missed out as ARC port was
not yet mainline.
[vgupta: commit log modified]
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
commit "fs: make binfmt support for #! scripts modular and removable"
made support for #!scripts optional - thus need to include the Kconfig
file to get all relevant BINFMT_*
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Currently ARC_HAS_LLSC can be influenced by platform for SMP only using
ARC_HAS_COH_LLSC. For !SMP it defaults to "y".
It turns out that some customers can't support it all, even in UP.
So we change the semantics, and use a negative dependency ARC_CANT_LLSC.
Any platform (independent of SMP or !SMP) can select it to disable LLSC.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
All the current platforms can work with 0x8000_0000 based dma_addr_t
since the Bus Bridges typically ignore the top bit (the only excpetion
was Angel4 PCI-AHB bridge which we no longer care for).
That way we don't need plat-specific cpu-addr to bus-addr conversion.
Hooks still provided - just in case a platform has an obscure device
which say needs 0 based bus address.
That way <asm/dma_mapping.h> no longer needs to unconditinally include
<plat/dma_addr.h>
Also verfied that on Angel4 board, other peripherals (IDE-disk / EMAC)
work fine with 0x8000_0000 based dma addresses.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
This is more natural and is now doable since the choice constructs are
gone.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
This mini patchseries addresses the lack of multi-platform-image support
in ARC port.
Older build system only supported one platform(soc) to build at a time
and further only one board of that platform could be built. There was no
technical reason for that - we just didn't have the need.
So the first step towards multi-platform (and multi-board) builds it to
allow build system to do that.
So as applicable, <choice .. endchoice> => <menu .. endmenu>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Implement ioremap_prot() to allow mapping IO memory with variable
protection
via TLB.
Implementing this allows the /dev/mem driver to use its generic access()
VMA callback, which in turn allows ptrace to examine data in memory
mapped regions mapped via /dev/mem, such as Arc DCCM.
The end result is that it is possible to examine values of variables
placed into DCCM in user space programs via GDB.
CC: Alexey Brodkin <Alexey.Brodkin@synopsys.com>
CC: Noam Camus <noamc@ezchip.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Vineet Gupta
