Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751633Ab3FYOML (ORCPT ); Tue, 25 Jun 2013 10:12:11 -0400 Received: from e06smtp11.uk.ibm.com ([195.75.94.107]:42701 "EHLO e06smtp11.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751102Ab3FYOMJ (ORCPT ); Tue, 25 Jun 2013 10:12:09 -0400 Date: Tue, 25 Jun 2013 16:12:02 +0200 From: Martin Schwidefsky To: Grant Likely Cc: Linus Torvalds , linux-kernel , linux-s390 , Heiko Carstens Subject: Re: [GIT PULL] s390 patches for the 3.9-rc6 Message-ID: <20130625161202.4d0a0075@mschwide> In-Reply-To: References: <20130403172534.528d04c5@mschwide> <20130625141508.6c391fd8@mschwide> <20130625151151.73aaba28@mschwide> Organization: IBM Corporation X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13062514-5024-0000-0000-0000066BB098 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2733 Lines: 64 On Tue, 25 Jun 2013 14:30:20 +0100 Grant Likely wrote: > On Tue, Jun 25, 2013 at 2:11 PM, Martin Schwidefsky > wrote: > > On Tue, 25 Jun 2013 13:42:23 +0100 > > Grant Likely wrote: > > > >> On Tue, Jun 25, 2013 at 1:15 PM, Martin Schwidefsky > >> wrote: > >> > On Tue, 25 Jun 2013 13:09:51 +0100 > >> > Grant Likely wrote: > >> > > >> >> On Wed, Apr 3, 2013 at 4:25 PM, Martin Schwidefsky > >> >> wrote: > >> >> > Hi Linus, > >> >> > > >> >> > please pull from the 'for-linus' branch of > >> >> > > >> >> > git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git for-linus > >> >> > > >> >> > to receive the following updates: Just a bunch of bugfixes. > >> >> > > >> >> > Heiko Carstens (4): > >> >> > drivers/Kconfig: add several missing GENERIC_HARDIRQS dependencies > >> >> > >> >> Is anyone currently working on fixing this? s390 is the only > >> >> architecture left that does not enable GENERIC_HARDIRQS. It's painful > >> >> to keep adding dependencies on GENERIC_HARDIRQS to driver configs. > >> > > >> > I am working on it. The hardest part is MSI irqs for PCI. Chances are > >> > that I get it done for the merge window of 3.12. > >> > >> How are you handling the MSIs? I've just been looking at some code for > >> irq_domain to handle MSI mapping. What's the part that is getting you > >> hung up? > > > > Basically a name-space thing. The current code allocates 64 interrupts numbers > > for each PCI device, starting at 0. With GENERIC_HARDIRQS=y irq #0 is used for > > for external interrupts, irq #1 for I/O interrupts and irq #2 for adapter > > interrupts. The adapter interrupt handler for PCI has to scan the interrupt > > vectors and call generic_handle_irq for the MSI interrupts starting at irq #3. > > As I don't want to create a huge irq_desc array the number of allocatable > > interrupts for MSI will be limited and I can not simply assign 64 interrupts > > numbers to each device anymore. > > Have you looked at irq_domain? It was created to solve that exact > problem. irq_descs can get allocated dynamically as irqs are > requested. That is one option I am considering. The PCI support for System z can have multiple PCI function groups, each with up to 2048 MSI interrupts. It is quite a good match. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. -- 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/