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: NDavid S. Miller <davem@davemloft.net>

The only real user was the assembler floppy interrupt
handler, which does not need to be in assembly.

This makes it so that there are less pieces of code which
know about the internal layout of ivector_table[] and
friends.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In particular, avoid membar instructions in the delay
slot of a jmpl instruction.

UltraSPARC-I, II, IIi, and IIe have a bug, documented in
the UltraSPARC-IIi User's Manual, Appendix K, Erratum 51

The long and short of it is that if the IMU unit misses
on a branch or jmpl, and there is a store buffer synchronizing
membar in the delay slot, the chip can stop fetching instructions.

If interrupts are enabled or some other trap is enabled, the
chip will unwedge itself, but performance will suffer.

We already had a workaround for this bug in a few spots, but
it's better to have the entire tree sanitized for this rule.
Signed-off-by: NDavid 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!