Signed-off-by: NJens Axboe <axboe@carl.home.kernel.dk>

Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Since we have to be able to handle MD updates, having an in-tree
set of data structures representing the MD objects actually makes
things more painful.

The MD itself is easy to parse, and we can implement the existing
interfaces using direct parsing of the MD binary image.

The MD is now reference counted, so accesses have to now take the
form:

	handle = mdesc_grab();

	... operations on MD ...

	mdesc_release(handle);

The only remaining issue are cases where code holds on to references
to MD property values.  mdesc_get_property() returns a direct pointer
to the property value, most cases just pull in the information they
need and discard the pointer, but there are few that use the pointer
directly over a long lifetime.  Those will be fixed up in a subsequent
changeset.

A preliminary handler for MD update events from domain services is
there, it is rudimentry but it works and handles all of the reference
counting.  It does not check the generation number of the MDs,
and it does not generate a "add/delete" list for notification to
interesting parties about MD changes but that will be forthcoming.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All of the interrupts say "LDX RX" and "LDX TX" currently
which is next to useless.  Put a device specific prefix
before "RX" and "TX" instead which makes it much more
useful.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

1) LDC_MODE_RELIABLE is deprecated an unused by anything, plus
   it and LDC_MODE_STREAM were mis-numbered.

2) read_stream() should try to read as much as possible into
   the per-LDC stream buffer area, so do not trim the read_nonraw()
   length by the caller's size parameter.

3) Send data ACKs when necessary in read_nonraw().

4) In read_nonraw() when we get a pure ACK, advance the RX head
   unconditionally past it.

5) Provide the ACKID field in the ldcdgb() packet dump in read_nonraw().
   This helps debugging stream mode LDC channel problems.

6) Decrease verbosity of rx_data_wait() so that it is more useful.
   A debugging message each loop iteration is too much.

7) In process_data_ack() stop the loop checking when we hit lp->tx_tail
   not lp->tx_head.

8) Set the seqid field properly in send_data_nack().
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Virtual devices on Sun Logical Domains are built on top
of a virtual channel framework.  This, with help of hypervisor
interfaces, provides a link layer protocol with basic
handshaking over which virtual device clients and servers
communicate.

Built on top of this is a VIO device protocol which has it's
own handshaking and message types.  At this layer attributes
are exchanged (disk size, network device addresses, etc.)
descriptor rings are registered, and data transfers are
triggers and replied to.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>