Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751633Ab3FYOSn (ORCPT ); Tue, 25 Jun 2013 10:18:43 -0400 Received: from mail-ie0-f173.google.com ([209.85.223.173]:55677 "EHLO mail-ie0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751250Ab3FYOSl (ORCPT ); Tue, 25 Jun 2013 10:18:41 -0400 MIME-Version: 1.0 In-Reply-To: <20130625161202.4d0a0075@mschwide> References: <20130403172534.528d04c5@mschwide> <20130625141508.6c391fd8@mschwide> <20130625151151.73aaba28@mschwide> <20130625161202.4d0a0075@mschwide> From: Grant Likely Date: Tue, 25 Jun 2013 15:18:21 +0100 X-Google-Sender-Auth: FpS8ei7KFBdWoWwXwiA758yLxb0 Message-ID: Subject: Re: [GIT PULL] s390 patches for the 3.9-rc6 To: Martin Schwidefsky Cc: Linus Torvalds , linux-kernel , linux-s390 , Heiko Carstens Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2865 Lines: 63 On Tue, Jun 25, 2013 at 3:12 PM, Martin Schwidefsky wrote: > 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. :-) It was designed to support exactly that use-case on PowerPC. g. -- 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/