I have added a hangup notifier that can be used by hvc console
backends to handle a tty hangup. The default irq hangup notifier
calls the notifier_del_irq() for compatibility.
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This patch exploits the new notifier callbacks of the hvc_console. We can
use the virtio callbacks instead of the polling code.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Previously we used a type/len pair within the config space, but this
seems overkill.  We now simply define a structure which represents the
layout in the config space: the config space can now only be extended
at the end.

The main driver-visible changes:
1) We indicate what fields are present with an explicit feature bit.
2) Virtqueues are explicitly numbered, and not in the config space.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Make virtcons_probe() __devinit.
Fixes this section warning:

WARNING: vmlinux.o(.text+0x14c10b): Section mismatch: reference to .init.text:hvc_alloc (between 'virtcons_probe' and 'ac_register_board')
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is an hvc-based virtio console driver.  It's suboptimal becuase
hvc expects to have raw access to interrupts and virtio doesn't assume
that, so it currently polls.

There are two solutions: expose hvc's "kick" interface, or wean off hvc.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>