From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:11546 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726183AbgIZMjr (ORCPT ); Sat, 26 Sep 2020 08:39:47 -0400 Date: Sat, 26 Sep 2020 14:38:53 +0200 From: Vasily Gorbik Subject: Re: [patch V2 34/46] PCI/MSI: Make arch_.*_msi_irq[s] fallbacks selectable Message-ID: References: <20200826111628.794979401@linutronix.de> <20200826112333.992429909@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: List-ID: To: Thomas Gleixner , Qian Cai Cc: LKML , Heiko Carstens , Christian Borntraeger , linux-s390@vger.kernel.org, Stephen Rothwell , linux-next@vger.kernel.org, x86@kernel.org, Joerg Roedel , iommu@lists.linux-foundation.org, linux-hyperv@vger.kernel.org, Haiyang Zhang , Jon Derrick , Lu Baolu , Wei Liu , "K. Y. Srinivasan" , Stephen Hemminger , Steve Wahl , Dimitri Sivanich , Russ Anderson , linux-pci@vger.kernel.org, Bjorn Helgaas , Lorenzo Pieralisi , Konrad Rzeszutek Wilk , xen-devel@lists.xenproject.org, Juergen Gross , Boris Ostrovsky , Stefano Stabellini , Marc Zyngier , Greg Kroah-Hartman , "Rafael J. Wysocki" , Megha Dey , Jason Gunthorpe , Dave Jiang , Alex Williamson , Jacob Pan , Baolu Lu , Kevin Tian , Dan Williams On Fri, Sep 25, 2020 at 09:54:52AM -0400, Qian Cai wrote: > On Wed, 2020-08-26 at 13:17 +0200, Thomas Gleixner wrote: > > From: Thomas Gleixner > > > > The arch_.*_msi_irq[s] fallbacks are compiled in whether an architecture > > requires them or not. Architectures which are fully utilizing hierarchical > > irq domains should never call into that code. > > > > It's not only architectures which depend on that by implementing one or > > more of the weak functions, there is also a bunch of drivers which relies > > on the weak functions which invoke msi_controller::setup_irq[s] and > > msi_controller::teardown_irq. > > > > Make the architectures and drivers which rely on them select them in Kconfig > > and if not selected replace them by stub functions which emit a warning and > > fail the PCI/MSI interrupt allocation. > > > > Signed-off-by: Thomas Gleixner > > Today's linux-next will have some warnings on s390x: > > .config: https://gitlab.com/cailca/linux-mm/-/blob/master/s390.config > > WARNING: unmet direct dependencies detected for PCI_MSI_ARCH_FALLBACKS > Depends on [n]: PCI [=n] > Selected by [y]: > - S390 [=y] > > WARNING: unmet direct dependencies detected for PCI_MSI_ARCH_FALLBACKS > Depends on [n]: PCI [=n] > Selected by [y]: > - S390 [=y] > Yes, as well as on mips and sparc which also don't FORCE_PCI. This seems to work for s390: diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index b0b7acf07eb8..41136fbe909b 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -192,3 +192,3 @@ config S390 select PCI_MSI if PCI - select PCI_MSI_ARCH_FALLBACKS + select PCI_MSI_ARCH_FALLBACKS if PCI select SET_FS