Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753034AbbH2APA (ORCPT ); Fri, 28 Aug 2015 20:15:00 -0400 Received: from mx2.suse.de ([195.135.220.15]:53842 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752915AbbH2AO5 (ORCPT ); Fri, 28 Aug 2015 20:14:57 -0400 Date: Sat, 29 Aug 2015 02:14:52 +0200 From: "Luis R. Rodriguez" To: Guenter Roeck Cc: Ingo Molnar , "Luis R. Rodriguez" , schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, linux-s390@vger.kernel.org, bp@suse.de, plagnioj@jcrosoft.com, tomi.valkeinen@ti.com, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, fengguang.wu@intel.com, akpm@linux-foundation.org, rostedt@goodmis.org, linux-arch@vger.kernel.org Subject: Re: [PATCH] S390: add pci_iomap_wc() and pci_iomap_wc_range() Message-ID: <20150829001452.GJ8051@wotan.suse.de> References: <1440632050-23648-1-git-send-email-mcgrof@do-not-panic.com> <20150828060605.GF26741@gmail.com> <55E01A43.9080109@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <55E01A43.9080109@roeck-us.net> 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: 2689 Lines: 66 On Fri, Aug 28, 2015 at 01:22:27AM -0700, Guenter Roeck wrote: > On 08/27/2015 11:06 PM, Ingo Molnar wrote: > > > >* Luis R. Rodriguez wrote: > > > >>From: "Luis R. Rodriguez" > >> > >>S390 requires its own implementation of pcio_iomap*() calls > >>is because it has its "BAR spaces are not disjunctive on s390 > >>so we need the bar parameter of pci_iomap to find the corresponding > >>device and create the mapping cookie" -- in summary, it has its own > >>lookup/lock solution. > >> > >>It does not include asm-generic/pci_iomap.h > >> > >>Since it currenty maps ioremap_wc() to ioremap_nocache() and that's > >>the architecture default we can easily just map the wc calls to > >>the default calls as well. > >> > >>Cc: Guenter Roeck > >>Cc: Jean-Christophe Plagniol-Villard > >>Cc: Tomi Valkeinen > >>Cc: linux-fbdev@vger.kernel.org > >>Cc: linux-kernel@vger.kernel.org > >>Cc: Borislav Petkov > >>Cc: Ingo Molnar > >>Cc: Fengguang Wu > >>Cc: Andrew Morton > >>Cc: Steven Rostedt > >>Reported-by: 0 day bot > >>Signed-off-by: Luis R. Rodriguez > >>--- > >> > >>This broke through some series that went into Ingo's tip tree which > >>I added. As such I *think* this should go through Ingo's tip tree. > >>Let me know. Up to you guys. > > > >I fixed the changelog to explain all this. > > > >Also, is there any other architecture that got broken by: > > > > 1b3d4200c1e0 PCI: Add pci_iomap_wc() variants > > > > Should be the only one. There are only two implementations of pci_iomap(), > one in s390 code and the generic implementation. Indeed, sadly there is no semantics well defined to establish this requirement so the best we can do is infer: mcgrof@ergon ~/linux-next (git::20150805-pend-all)$ git grep pci_iomap_range arch/ arch/s390/include/asm/io.h:#define pci_iomap_wc_range pci_iomap_range arch/s390/pci/pci.c:void __iomem *pci_iomap_range(struct pci_dev *pdev, arch/s390/pci/pci.c:EXPORT_SYMBOL(pci_iomap_range); arch/s390/pci/pci.c: return pci_iomap_range(dev, bar, 0, maxlen); To this end a Kconfig option to implicate this might be more well suited for future lookups and make other architectures which are incompatible with generic pci_iomap clearer. Will post an RFC. Luis -- 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/