Make some changes to the NEED_RESCHED and POLLING_NRFLAG to reduce
confusion, and make their semantics rigid. Improves efficiency of
resched_task and some cpu_idle routines.
* In resched_task:
- TIF_NEED_RESCHED is only cleared with the task's runqueue lock held,
and as we hold it during resched_task, then there is no need for an
atomic test and set there. The only other time this should be set is
when the task's quantum expires, in the timer interrupt - this is
protected against because the rq lock is irq-safe.
- If TIF_NEED_RESCHED is set, then we don't need to do anything. It
won't get unset until the task get's schedule()d off.
- If we are running on the same CPU as the task we resched, then set
TIF_NEED_RESCHED and no further action is required.
- If we are running on another CPU, and TIF_POLLING_NRFLAG is *not* set
after TIF_NEED_RESCHED has been set, then we need to send an IPI.
Using these rules, we are able to remove the test and set operation in
resched_task, and make clear the previously vague semantics of
POLLING_NRFLAG.
* In idle routines:
- Enter cpu_idle with preempt disabled. When the need_resched() condition
becomes true, explicitly call schedule(). This makes things a bit clearer
(IMO), but haven't updated all architectures yet.
- Many do a test and clear of TIF_NEED_RESCHED for some reason. According
to the resched_task rules, this isn't needed (and actually breaks the
assumption that TIF_NEED_RESCHED is only cleared with the runqueue lock
held). So remove that. Generally one less locked memory op when switching
to the idle thread.
- Many idle routines clear TIF_POLLING_NRFLAG, and only set it in the inner
most polling idle loops. The above resched_task semantics allow it to be
set until before the last time need_resched() is checked before going into
a halt requiring interrupt wakeup.
Many idle routines simply never enter such a halt, and so POLLING_NRFLAG
can be always left set, completely eliminating resched IPIs when rescheduling
the idle task.
POLLING_NRFLAG width can be increased, to reduce the chance of resched IPIs.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Con Kolivas <kernel@kolivas.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Run idle threads with preempt disabled.
Also corrected a bugs in arm26's cpu_idle (make it actually call schedule()).
How did it ever work before?
Might fix the CPU hotplugging hang which Nigel Cunningham noted.
We think the bug hits if the idle thread is preempted after checking
need_resched() and before going to sleep, then the CPU offlined.
After calling stop_machine_run, the CPU eventually returns from preemption and
into the idle thread and goes to sleep. The CPU will continue executing
previous idle and have no chance to call play_dead.
By disabling preemption until we are ready to explicitly schedule, this bug is
fixed and the idle threads generally become more robust.
From: alexs <ashepard@u.washington.edu>
PPC build fix
From: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
MIPS build fix
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch removes almost all inclusions of linux/version.h. The 3
#defines are unused in most of the touched files.
A few drivers use the simple KERNEL_VERSION(a,b,c) macro, which is
unfortunatly in linux/version.h.
There are also lots of #ifdef for long obsolete kernels, this was not
touched. In a few places, the linux/version.h include was move to where
the LINUX_VERSION_CODE was used.
quilt vi `find * -type f -name "*.[ch]"|xargs grep -El '(UTS_RELEASE|LINUX_VERSION_CODE|KERNEL_VERSION|linux/version.h)'|grep -Ev '(/(boot|coda|drm)/|~$)'`
search pattern:
/UTS_RELEASE\|LINUX_VERSION_CODE\|KERNEL_VERSION\|linux\/\(utsname\|version\).h
Signed-off-by: Olaf Hering <olh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
save_and_disable_irqs does not need to use mov + msr (which was
introduced to work around a documentation bug which was propagated
into binutils.) Use msr with an immediate constant, and if we're
building for ARMv6 or later, use the new CPSID instruction.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Ben Dooks
Fix the map_desc initialisers for the SMDK2440 machine
to use the new .pfn method, and at the same time making
the differntiation between ISA IO and Memory space
accesses
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Ben Dooks
Change the initialiser for the map_desc for the
iPAQ RX3715 to use the new pfn initialiser, and
also reduce the amount of ISA space mapped (we
only need to stop any ISA IO writes OOPsing
the system, so do not need >1Mbyte of space)
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Ben Dooks
Fix the map_desc initialisers for the Simtec Anubis
board to match the new initialiser scheme.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Nicolas Pitre
Make it completely deterministic and leave nothing to chance
(even if it had at worst 0.001% probability of failing).
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Nicolas Pitre
Noticed by Woody Suwalski <woodys@xandros.com>.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Ben Dooks
Force a watchdog reset if the system fails to
decompress properly.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Dirk Opfer
This patch updates the tosa machine to use the new SharpSL PCMCIA layer introduced with Patch #3093/1
Depends on #3093/1
Signed-off-by: Dirk Opfer <Dirk@Opfer-Online.de>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Richard Purdie
The Sharp SL-Cxx00 models have a combined power control for the SD
and CF slot 0. This patch adds hooks to the scoop driver to allow
machines to provide a custom control function for this and such a
function is added for spitz/akita/borzoi.
It also moves the gpio init code into the machine files as this
is machine dependent and differs between some models. A couple of
warnings when compiling for collie are also fixed.
Signed-off-by: Richard Purdie
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Ben Dooks
Fix the map_desc entries to use the new .pfn
initialiser for the Simtec BAST machine support.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Ben Dooks
Fix the initialisation of the map_desc fields
in the Thorcom VR1000 machine support to use
the new .pfn initialiser.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Dirk Opfer
This patch adds MMC, IRDA and UDC support to the Sharp SL-6000x device. Also it adds a platform device for the keyboard driver.
Signed-off-by: Dirk Opfer
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add infrastructure for supporting per-cpu local timers to update
the profiling information and update system time accounting.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
arch/arm/kernel/irq.c:998:26: warning: Using plain integer as NULL pointer
arch/arm/kernel/smp.c:145:25: warning: Using plain integer as NULL pointer
arch/arm/kernel/smp.c:362:5: warning: symbol 'smp_call_function_on_cpu' was not declared. Should it be static?
drivers/video/amba-clcd.c:521:12: warning: symbol 'amba_clcdfb_init' was not declared. Should it be static?
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Until we have local timer support, we need to broadcast the
timer interrupt to the other CPUs. Also, add the missing
smp_send_timer() prototype to asm/smp.h
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
Since we have to use XCB=101 instead of XCB=000 on the ixp2400 to
prevent it from regularly falling over, and since we have to deal with
manual write buffer flushing because of that, we might as well use
XCB=101 on all ixp2000 platforms since it's faster than XCB=000.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
nwfpe extended precision emulation used to be broken on big-endian
and was therefore disabled. This patch fixes nwfpe so that it copies
extended precision floats to/from userspace in the proper word order
(similar to patch #2046, see the description of that patch for an
explanation) and reenables the Kconfig option.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
The routine that nwfpe uses for converting floats/doubles to
extended precision fails to zero two bytes of kernel stack. This
is not immediately obvious, as the floatx80 structure has 16 bits
of implicit padding (by design.) These two bytes are copied to
userspace when an stfe is emulated, causing a possible info leak.
Make the padding explicit and zero it out in the relevant places.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This is the arch/ part of the big kfree cleanup patch.
Remove pointless checks for NULL prior to calling kfree() in arch/.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The sys_ptrace boilerplate code (everything outside the big switch
statement for the arch-specific requests) is shared by most architectures.
This patch moves it to kernel/ptrace.c and leaves the arch-specific code as
arch_ptrace.
Some architectures have a too different ptrace so we have to exclude them.
They continue to keep their implementations. For sh64 I had to add a
sh64_ptrace wrapper because it does some initialization on the first call.
For um I removed an ifdefed SUBARCH_PTRACE_SPECIAL block, but
SUBARCH_PTRACE_SPECIAL isn't defined anywhere in the tree.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Paul Mackerras <paulus@samba.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-By: David Howells <dhowells@redhat.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix more include file problems that surfaced since I submitted the previous
fix-missing-includes.patch. This should now allow not to include sched.h
from module.h, which is done by a followup patch.
Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We need to set the shared memory attribute in the page tables
on SMP systems to allow the cache coherency to operate.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
glibc expects to count lines beginning with "processor" to determine
the number of processors, not lines beginning with "Processor". So,
give glibc the format it expects.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We don't want to call dump_cpu_info() from cpu_init() after boot since
it produces a lot of unnecessary noise - since cpu_init() gets called
on resume and hotplug cpu insertion events.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Richard Purdie
Update the PXA pm.c file to allow machines (such as the Sharp
Zaurus) to override the standard pm functions but reuse/wrap them
where needed.
The init call is made slightly earlier to give machine code an init
level to override them in removing any race.
Signed-off-by: Richard Purdie
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Nicolas Pitre
Since we know the value of cpsr on entry, we can replace the bic+orr with
a single eor. Also remove a possible result delay (at least on XScale).
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
Make the uengine loader use ixp2000_reg_wrb in the right places.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Alessandro Zummo
This patch fixes AHB/PCI endianness problems when the
processor is in little-endian mode.
The patch configures the CSR register closely following the directives
in [1], paragraph 4.1, page 19.
According to the considerations in [1], page 11, while the AHB bus
supports both endian modes, on the IXP4XX it always uses big-endian.
The PCI bus is connected to the South AHB. A wrong setting in the CSR
register will thus cause a malfunctional PCI bus.
A schematic diagram of the bus interconnections on the IXP4XX
can be found in [1], page 18.
The patch has been verified to work on the NSLU2 in
both LE and BE modes.
The author is Peter Korsgaard.
[1] Intel® IXP4XX Product Line of Network Processors and IXC1100
Control Plane Processor:
Understanding Big Endian and Little Endian Modes
http://www.intel.com/design/network/applnots/25423701.pdf
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Dirk Opfer
This patch adds basic machine support for the Sharp SL-6000x (Tosa) PDAs.
Signed-off-by: Dirk Opfer
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Nicolas Pitre
We have an optimized sha1 routine (arch/arm/lib/sha1.S) meant to
override the generic one in lib/sha1.c.
Unfortunately lib/lib.a is listed _before_ arch/arm/lib/lib.a in the
link argument list and therefore the architecture specific lib functions
are not picked up before the generic versions.
This patch is a quick fix to change that ordering for ARM. Here's what
the kbuild maintainer had to say about it (was also CC'd on lkml):
On Wed, 2 Nov 2005, Sam Ravnborg wrote:
> This looks like an obvious way to achive correct ordering.
> We could change it so arch defines always took precedence but
> the above is so simple that it is not worth the effort.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Todd Poynor
Add platform devices for flash to Lubbock and Mainstone board files.
Once in place, the two existing mtd map drivers for the boards will be
converted to use a single pxa2xx map driver in the linux-mtd tree.
Take 4: flash_platform_data .map_name vs. .name cleaned up, resync with
merged irda patch context.
Signed-off-by: Todd Poynor <tpoynor@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
