Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932885AbWLNSAc (ORCPT ); Thu, 14 Dec 2006 13:00:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932884AbWLNSAc (ORCPT ); Thu, 14 Dec 2006 13:00:32 -0500 Received: from cantor2.suse.de ([195.135.220.15]:39268 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932886AbWLNSAb (ORCPT ); Thu, 14 Dec 2006 13:00:31 -0500 Date: Thu, 14 Dec 2006 10:00:08 -0800 From: Greg KH To: Avi Kivity Cc: Hans-J?rgen Koch , linux-kernel@vger.kernel.org Subject: Re: Userspace I/O driver core Message-ID: <20061214180008.GA24568@kroah.com> References: <20061214010608.GA13229@kroah.com> <45811D0F.2070705@argo.co.il> <200612141125.14777.hjk@linutronix.de> <45812C17.4090309@argo.co.il> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <45812C17.4090309@argo.co.il> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1902 Lines: 52 On Thu, Dec 14, 2006 at 12:48:55PM +0200, Avi Kivity wrote: > [why trim the cc?] > > Hans-J?rgen Koch wrote: > >Am Donnerstag, 14. Dezember 2006 10:44 schrieb Avi Kivity: > > > > > >>I understand one still has to write a kernel driver to shut up the irq. > >>How about writing a small bytecode interpreter to make event than > >>unnecessary? > >> > >>The userspace driver would register a couple of bytecode programs: > >>is_interrupt_pending() and disable_interrupt(), which the uio framework > >>would call when the interrupt fires. > >> > >>The bytecode could reuse net/core/filter.c, with the packet replaced by > >>the mmio or ioregion, or use something new. > >> > >> > > > >I think this would be overkill. The kernel module you have to write > >is _really_ very simple. And it has to be written only once, so even > >a manufacturer who employs no experienced kernel developers can > >easily outsource that task. > > > > > > It has to be written once, but compiled for every kernel version and > $arch out there (for out of tree drivers), or it has to wait for the > next kernel release and distro sync (for in-tree drivers). No, just get the tiny driver into the main kernel tree, like all other drivers are required to do. > If we make userspace drivers possible, it makes sense that the entire > driver be in userspace, not just 98.7% of it. If you see a way to do this that is race-free, I know a lot of people would be glad to see such a patch. But until then, no, we are not making any such claims of 100% userspace driver for hardware such as pci devices and other things that this uio core works with. thanks, greg k-h - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/