Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

Usually our cards are used in MSI mode. On older motherboards, they
can fall back to classic interrupt generation. However, then the
interrupt enable register in the card must be turned on.

Previously, the interrupt handler popped the data from the hardware.
To do this, it needed to lock the target buffers, guarded by a mutex.
Unfortunately, that can cause the interrupt handler to sleep! bad!

This patch moves the waitq and fasync structure to the wishbone structure
which is always present.  Then, the interrupt handler need only wake up any
threads blocked waiting for data.  The read/poll functions invoke the
processing of data from the hardware, instead.

The drivers were popping the slave request FIFO, whether it was empty or not.
This seemed safe since empty FIFOs do nothing when popped. However, if the
FIFO receives an element between the empty check and the pop, we might pop
an element without ever seeing it. Under load this led to lost interrupts.

            used in caparisons in VHDL 2008

Trying to manage an external repository that was optionally built
or not depending on the kernel version was a nightmare.

Including it lets us use a single Makefile that does the right thing.

        against the vme in-tree  kernle module, it's not ready though

        fixing merge conflict

Conflicts:
	vme-wb/vme_wb.c

        address

        The chip tundra doesn't support 8 bit data width transfer.
        The wb select in the VME slave is written from wb_byteenable,
        who calculates it. The write and read is always 32 bit.
        Replaced swapbe32 by the macro cpu_to_be32.

Added Cesar's driver for VME.

better if it looks like one

the IRQ subscription is done using the VME driver
handling of the IRQ, request and response is done using
the etherbone library

if need be

since KBUILD_EXTMOD and KBUILD_EXTRA_SYMBOLS compilations
options don't work, I have create the one manually,
it seems to work

	Now it uses three windows:
	1) CR/CSR
	2) WB Control, 24A access
	3) WB Data,    32A access