Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752452AbdIVP4I (ORCPT ); Fri, 22 Sep 2017 11:56:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:59310 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752125AbdIVP4H (ORCPT ); Fri, 22 Sep 2017 11:56:07 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B9512214F0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=helgaas@kernel.org Date: Fri, 22 Sep 2017 10:56:05 -0500 From: Bjorn Helgaas To: Geert Uytterhoeven Cc: Bjorn Helgaas , Arnd Bergmann , Alex Williamson , Joerg Roedel , linux-pci@vger.kernel.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] pci: Add dummy for pci_acs_enabled() if CONFIG_PCI=n to fix iommmu build Message-ID: <20170922155605.GB15970@bhelgaas-glaptop.roam.corp.google.com> References: <1505132955-9517-1-git-send-email-geert@linux-m68k.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1505132955-9517-1-git-send-email-geert@linux-m68k.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1908 Lines: 52 On Mon, Sep 11, 2017 at 02:29:15PM +0200, Geert Uytterhoeven wrote: > If CONFIG_PCI=n, and gcc (e.g. 4.1.2) decides not to inline > get_pci_function_alias_group(), the build fails with: > > drivers/iommu/iommu.o: In function `get_pci_function_alias_group': > iommu.c:(.text+0xfdc): undefined reference to `pci_acs_enabled' > > Due to the various dummies for PCI calls in the CONFIG_PCI=n case, > pci_acs_enabled() isn't actually ever called, but not all versions of > gcc are smart enough to realize that. > > While explicitly marking get_pci_function_alias_group() inline would fix > the build, this would inflate the code for the CONFIG_PCI=y case, as > get_pci_function_alias_group() is a not-so-small function called from > two places. > > Hence fix the issue by introducing a dummy for pci_acs_enabled() > instead. > > Signed-off-by: Geert Uytterhoeven Acked-by: Bjorn Helgaas Joerg, if you pick this up, would you mind capitalizing the subject line to match the PCI convention, e.g., PCI: Add dummy pci_acs_enabled() for CONFIG_PCI=n build If it's too late for you to pick this up this week, I can include it next week. I assume this is not related to a specific change, i.e., it's not a regression? Should it be marked for stable? > --- > include/linux/pci.h | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/include/linux/pci.h b/include/linux/pci.h > index f68c58a93dd045b9..f4f8ee5a7362e982 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1685,6 +1685,8 @@ static inline int pci_get_new_domain_nr(void) { return -ENOSYS; } > > #define dev_is_pci(d) (false) > #define dev_is_pf(d) (false) > +static inline bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags) > +{ return false; } > #endif /* CONFIG_PCI */ > > /* Include architecture-dependent settings and functions */ > -- > 2.7.4 >