From mboxrd@z Thu Jan 1 00:00:00 1970 From: iws@ovro.caltech.edu (Ira W. Snyder) Date: Mon, 14 Feb 2011 08:53:27 -0800 Subject: [RFC] Inter-processor Mailboxes Drivers In-Reply-To: References: <4D55A7F7.5090700@mentor.com> <20110214100104.GC4371@pulham.picochip.com> Message-ID: <20110214165327.GB13271@ovro.caltech.edu> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Feb 14, 2011 at 12:03:59PM +0200, Ohad Ben-Cohen wrote: > On Mon, Feb 14, 2011 at 12:01 PM, Jamie Iles wrote: > > On Fri, Feb 11, 2011 at 03:19:51PM -0600, Meador Inge wrote: > >> ? ? 1. Hardware specific bits somewhere under '.../arch/*'. ?Drivers > >> ? ? ? ?for the MPIC message registers on Power and OMAP4 mailboxes, for > >> ? ? ? ?example. > >> ? ? 2. A higher level driver under '.../drivers/mailbox/*'. ?That the > >> ? ? ? ?pieces in (1) would register with. ?This piece would expose the > >> ? ? ? ?main kernel API. > >> ? ? 3. Userspace interfaces for accessing the mailboxes. ?A > >> ? ? ? ?'/dev/mailbox1', '/dev/mailbox2', etc... mapping, for example. > > > > How about using virtio for all of this and having the mailbox as a > > notification/message passing driver for the virtio backend? > > This is exactly what we are doing now, and it looks promising. expect > patches soon. I'll be happy to examine the feasibility of doing a port to mpc83xx as soon as I see the code. :-) I have been using the message registers to create a software "network card" over PCI (between a host system and an mpc83xx in a PCI slot). I have wanted to use virtio for this task for a long time. I think a uniform interface for the mailbox registers would be a very useful API. Thanks, Ira