Current implementation of spin_event_timeout can be interrupted by an
IRQ or context switch after testing the condition, but before checking
the timeout.  This can cause the loop to report a timeout when the
condition actually became true in the middle.

This patch adds one final check of the condition upon exit of the loop
if the last test of the condition was still false.
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NTimur Tabi <timur@freescale.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The macro spin_event_timeout() takes a condition and timeout value
(in microseconds) as parameters.  It spins until either the condition is true
or the timeout expires.  It returns the result of the condition when the loop
was terminated.

This primary purpose of this macro is to poll on a hardware register until a
status bit changes.  The timeout ensures that the loop still terminates if the
bit doesn't change as expected.  This macro makes it easier for driver
developers to perform this kind of operation properly.
Signed-off-by: NTimur Tabi <timur@freescale.com>
Acked-by: NGeoff Thorpe <Geoff.Thorpe@freescale.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

from include/asm-powerpc.  This is the result of a

mkdir arch/powerpc/include/asm
git mv include/asm-powerpc/* arch/powerpc/include/asm

Followed by a few documentation/comment fixups and a couple of places
where <asm-powepc/...> was being used explicitly.  Of the latter only
one was outside the arch code and it is a driver only built for powerpc.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

On partitioned PPC64 systems where a partition is given 1/10 of a
processor, we have seen mdelay() delaying for 10 times longer than it
should.  The reason is that the generic mdelay(n) does n delays of 1
millisecond each.  However, with 1/10 of a processor, we only get a
one-millisecond timeslice every 10ms.  Thus each 1 millisecond delay
loop ends up taking 10ms elapsed time.

The solution is just to use the PPC64 udelay function, which uses the
timebase to ensure that the delay is based on elapsed time rather than
how much processing time the partition has been given.  (Yes, the
generic mdelay uses the PPC64 udelay, but the problem is that the
start time gets reset every millisecond, and each time it gets reset
we lose another 9ms.)
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Acked-by: NAndrew Morton <akpm@osdl.org>

include/asm-ppc/ had #ifdef __KERNEL__ in all header files that
are not meant for use by user space, include/asm-powerpc does
not have this yet.

This patch gets us a lot closer there. There are a few cases
where I was not sure, so I left them out. I have verified
that no CONFIG_* symbols are used outside of __KERNEL__
any more and that there are no obvious compile errors when
including any of the headers in user space libraries.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

My earlier merge of delay.h introduced a timebase-based udelay for
32-bit machines but also broke the 601, which doesn't have the
timebase register.  This fixes it by using the 601's RTC register on
the 601, and also moves __delay() and udelay() to be out-of-line in
arch/powerpc/kernel/time.c.  These functions aren't really performance
critical, after all.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

... and also delete some that are no longer used because we already
had an include/asm-powerpc version of the header.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

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!