Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933319AbbGVIi5 (ORCPT ); Wed, 22 Jul 2015 04:38:57 -0400 Received: from mail-wi0-f172.google.com ([209.85.212.172]:38268 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932731AbbGVIiw (ORCPT ); Wed, 22 Jul 2015 04:38:52 -0400 Date: Wed, 22 Jul 2015 10:38:45 +0200 From: Ingo Molnar To: Bjorn Helgaas Cc: "Luis R. Rodriguez" , "Luis R. Rodriguez" , bp@suse.de, arnd@arndb.de, luto@amacapital.net, akpm@linux-foundation.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, tomi.valkeinen@ti.com, mst@redhat.com, toshi.kani@hp.com, linux-fbdev@vger.kernel.org, xen-devel@lists.xensource.com, benh@kernel.crashing.org Subject: Re: [PATCH v9 0/8] pci: add pci_iomap_wc() and pci_ioremap_wc_bar() Message-ID: <20150722083844.GA14626@gmail.com> References: <1436406859-1280-1-git-send-email-mcgrof@do-not-panic.com> <20150717202923.GC30479@wotan.suse.de> <20150721085252.GA15861@gmail.com> <20150721132157.GE16841@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150721132157.GE16841@google.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4064 Lines: 77 * Bjorn Helgaas wrote: > > > > Let me know if these are OK or if there are any questions. > > > > > > > > [0] http://lkml.kernel.org/r/20150625204703.GC4898@pd.tnic > > > > [1] http://lkml.kernel.org/r/20150707095012.GQ7021@wotan.suse.de > > > > > > Ingo, > > > > > > Just a friendly reminder. Let me know if there are any issues or questions. > > > > It would be nice to get an Acked-by from Bjorn for the PCI API bits. > > I think the actual code of pci_ioremap_wc() and pci_ioremap_wc_bar() is fine > (although I might have named it pci_ioremap_bar_wc() for consistency). > > I declined to merge or ack them myself because they're obvious extensions of > pci_ioremap() and pci_ioremap_bar(), and I would prefer that they be exported > the same way, i.e., with EXPORT_SYMBOL(), not EXPORT_SYMBOL_GPL(). Huh? AFAICS pci_ioremap_bar() has been a _GPL export for a long time: 1684f5ddd4c0c (Andrew Morton 2008-12-01 14:30:30 -0800 126)#ifdef CONFIG_HAS_IOMEM 1684f5ddd4c0c (Andrew Morton 2008-12-01 14:30:30 -0800 127)void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar) 1684f5ddd4c0c (Andrew Morton 2008-12-01 14:30:30 -0800 128){ 1f7bf3bfb5d60 (Bjorn Helgaas 2015-03-12 12:30:11 -0500 129) struct resource *res = &pdev->resource[bar]; 1f7bf3bfb5d60 (Bjorn Helgaas 2015-03-12 12:30:11 -0500 130) 1684f5ddd4c0c (Andrew Morton 2008-12-01 14:30:30 -0800 131) /* 1684f5ddd4c0c (Andrew Morton 2008-12-01 14:30:30 -0800 132) * Make sure the BAR is actually a memory resource, not an IO resource 1684f5ddd4c0c (Andrew Morton 2008-12-01 14:30:30 -0800 133) */ 646c0282df042 (Bjorn Helgaas 2015-03-12 12:30:15 -0500 134) if (res->flags & IORESOURCE_UNSET || !(res->flags & IORESOURCE_MEM)) { 1f7bf3bfb5d60 (Bjorn Helgaas 2015-03-12 12:30:11 -0500 135) dev_warn(&pdev->dev, "can't ioremap BAR %d: %pR\n", bar, res); 1684f5ddd4c0c (Andrew Morton 2008-12-01 14:30:30 -0800 136) return NULL; 1684f5ddd4c0c (Andrew Morton 2008-12-01 14:30:30 -0800 137) } 1f7bf3bfb5d60 (Bjorn Helgaas 2015-03-12 12:30:11 -0500 138) return ioremap_nocache(res->start, resource_size(res)); 1684f5ddd4c0c (Andrew Morton 2008-12-01 14:30:30 -0800 139)} 1684f5ddd4c0c (Andrew Morton 2008-12-01 14:30:30 -0800 140)EXPORT_SYMBOL_GPL(pci_ioremap_bar); 1684f5ddd4c0c (Andrew Morton 2008-12-01 14:30:30 -0800 141)#endif commit 1684f5ddd4c0c happened in 2008, well before you became PCI maintainer in 2012. and I'd prefer keeping the same EXPORT_SYMBOL_GPL() pattern for the new APIs. (ioremap_wc() is EXPORT_SYMBOL() mostly by accident, it's the odd one out.) Also, FWIIW: I personally got essentially zero feedback and help from proprietary binary kernel module vendors in the past couple of years as x86 maintainer, despite a fair chunk of kernel crashes reported on distro kernels occuring in them... Based on that very negative experience, when we introduce something as complex and as critical as new caching APIs, the last thing I want is to have obscure bugs in binary modules I cannot fix in any reasonable fashion. So even if the parent APIs of new APIs weren't already _GPL exports (as in this case), I'd export them as _GPL in this case. > I think using EXPORT_SYMBOL_GPL to express individual political aims rather than > as a hint about what might be derived work makes us look like zealots, and > that's not my style. As far as I'm concerned it's a pure technological choice: I don't want to export certain types of hard to fix and critical functionality to drivers that I cannot then fix. But I also applied EXPORT_SYMBOL() patches in the past, so I'm not one-sided about it. Thanks, Ingo -- 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/