The irqsoff tracer uses the atomic_* functions internally, but the
implementations of those functions in arch/sh/include/asm/atomic-irq.h
disable irqs to achieve atomicity. A continuous loop ensues where we
disable interrupts, trace the interrupt disabling, call atomic_*
functions, disable interrupts, trace the interrupt disabling, etc..

The simplest solution to all this is to just convert uses of
local_irq_save()/local_irq_restore() the raw_* equivalents because the
raw_* equivalents don't call trace_hardirqs_on()/trace_hardirqs_off().
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Now that atomic_t is a generic opaque type for all architectures, it is
unwise to use intimate knowledge of its internals when manipulating it.

Instead of relying on the "counter" member being at offset 0 from the
beginning of an atomic_t, explicitly reference the member. This guards
us from any changes to the layout of the beginning of the atomic_t type.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This follows the sparc changes a439fe51.

Most of the moving about was done with Sam's directions at:

http://marc.info/?l=linux-sh&m=121724823706062&w=2

with subsequent hacking and fixups entirely my fault.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

We have a few different ways to do the atomic operations, so split
them out in to different headers rather than bloating atomic.h.
Kernelspace gUSA will take this up to a third implementation.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>