Ensure a consistent value is read from the STICK register by ensuring
that both high and low are read without high changing due to a roll
over of the low register.
Various Debian/SPARC users (myself include) have noticed problems with
Hummingbird based systems. The symptoms are that the system time is
seen to jump forward 3 days, 6 hours, 11 minutes give or take a few
seconds. In many cases the system then hangs some time afterwards.
I've spotted a race condition in the code to read the STICK register.
I could not work out why 3d, 6h, 11m is important but guess that it is
due to the 2^32 jump of STICK (forwards on one read and then the next
read will seem to be backwards) during a timer interrupt. I'm guessing
that a change of -2^32 will get converted to a large unsigned
increment after the arithmetic manipulation between STICK,
nanoseconds, jiffies etc.
I did a test where I modified __hbird_read_stick to artificially
inject rollover faults forcefully every few seconds. With this I saw
the clock jump over 6 times in 12 hours compared to once every month
or so.
Signed-off-by: Richard Mortimer <richm@oldelvet.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
It only serves to generate false-positive buildcheck warnings.
Just set it initially to tick_operations which uses the v9
%tick register which every sparc64 processor has.
Signed-off-by: David S. Miller <davem@davemloft.net>
Define jiffies_64 in kernel/timer.c rather than having 24 duplicated
defines in each architecture.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch cleans up a commonly repeated set of changes to the NTP state
variables by adding two helper inline functions:
ntp_clear(): Clears the ntp state variables
ntp_synced(): Returns 1 if the system is synced with a time server.
This was compile tested for alpha, arm, i386, x86-64, ppc64, s390, sparc,
sparc64.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This allows a PCI controller to shim into IRQ delivery
so that DMA queues can be drained, if necessary.
If some bus specific code needs to run before an IRQ
handler is invoked, the bus driver simply needs to setup
the function pointer in bucket->irq_info->pre_handler and
the two args bucket->irq_info->pre_handler_arg[12].
The Schizo PCI driver is converted over to use a pre-handler
for the DMA write-sync processing it needs when a device
is behind a PCI->PCI bus deeper than the top-level APB
bridges.
While we're here, clean up all of the action allocation
and handling. Now, we allocate the irqaction as part of
the bucket->irq_info area. There is an array of 4 irqaction
(for PCI irq sharing) and a bitmask saying which entries
are active.
The bucket->irq_info is allocated at build_irq() time, not
at request_irq() time. This simplifies request_irq() and
free_irq() tremendously.
The SMP dynamic IRQ retargetting code got removed in this
change too. It was disabled for a few months now, and we
can resurrect it in the future if we want.
Signed-off-by: David S. Miller <davem@davemloft.net>
void * __iomem foo is not a pointer to iomem - it's an iomem variable
containing void *. A pile of such guys in arch/sparc64/kernel/time.c,
drivers/sbus/char/rtc.c and include/asm-sparc64/mostek.h turned into
intended void __iomem *.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Provide support for drivers/char/rtc.c ioctls in the
Mostek rtc driver as well as the Sparc specific RTCGET
and RTCSET.
This allows userspace to be much less messy. Currently
util-linux and other spots jump through hoops trying
various ioctl variants until it hits the right one whatever
driver actually being used supports.
Eventually all of this should move over to the genrtc.c
driver, but not today...
While we are here, fix up the register types for sparse.
Thanks to Frans Pop for helping point out this issue.
Signed-off-by: David S. Miller <davem@davemloft.net>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
