Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757569AbaKUEAX (ORCPT ); Thu, 20 Nov 2014 23:00:23 -0500 Received: from mail-oi0-f53.google.com ([209.85.218.53]:39198 "EHLO mail-oi0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756837AbaKUEAS (ORCPT ); Thu, 20 Nov 2014 23:00:18 -0500 MIME-Version: 1.0 In-Reply-To: <20141120222650.GC7987@google.com> References: <1416413091-13452-1-git-send-email-tomasz.nowicki@linaro.org> <1416413091-13452-7-git-send-email-tomasz.nowicki@linaro.org> <2360791.Aj7tQ0nCJ3@wuerfel> <20141120222650.GC7987@google.com> Date: Thu, 20 Nov 2014 21:00:17 -0700 Message-ID: Subject: Re: [PATCH 6/6] pci, acpi: Share ACPI PCI config space accessors. From: Myron Stowe To: Bjorn Helgaas Cc: Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Tomasz Nowicki , catalin.marinas@arm.com, will.deacon@arm.com, lorenzo.pieralisi@arm.com, wangyijing@huawei.com, hanjun.guo@linaro.org, Liviu.Dudau@arm.com, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , rjw@rjwysocki.net, linaro-acpi@lists.linaro.org, linux-pci , x86 , LKML , "linux-acpi@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 20, 2014 at 3:26 PM, Bjorn Helgaas wrote: > On Wed, Nov 19, 2014 at 05:19:20PM +0100, Arnd Bergmann wrote: >> On Wednesday 19 November 2014 17:04:51 Tomasz Nowicki wrote: >> > +/* >> > + * raw_pci_read/write - ACPI PCI config space accessors. >> > + * >> > + * ACPI spec defines MMCFG as the way we can access PCI config space, >> > + * so let MMCFG be default (__weak). >> > + * >> > + * If platform needs more fancy stuff, should provides its own implementation. >> > + */ >> > +int __weak raw_pci_read(unsigned int domain, unsigned int bus, >> > + unsigned int devfn, int reg, int len, u32 *val) >> > +{ >> > + return pci_mmcfg_read(domain, bus, devfn, reg, len, val); >> > +} >> > + >> > +int __weak raw_pci_write(unsigned int domain, unsigned int bus, >> > + unsigned int devfn, int reg, int len, u32 val) >> > +{ >> > + return pci_mmcfg_write(domain, bus, devfn, reg, len, val); >> > +} >> > + >> > >> >> I think it would be better to avoid __weak functions here, as they tend >> to be hard to follow when trying to understand the code. > > That's interesting. I would have said exactly the opposite -- I think the > extra Kconfiggery is harder to follow than weak/strong functions :) > > But consistency is better than my personal opinion. Is there a consensus > that we should use the Kconfig strategy instead of __weak? I too find weak/strong functions easier to follow than "Kconfiggery" (nice term invention there). > >> How about using a Kconfig symbol like this: >> >> #ifdef CONFIG_ARCH_RAW_PCI_READWRITE >> int raw_pci_read(unsigned int domain, unsigned int bus, unsigned int devfn, >> int reg, int len, u32 *val); >> int raw_pci_write(unsigned int domain, unsigned int bus, unsigned int devfn, >> int reg, int len, u32 val); >> #else >> static inline int raw_pci_read(unsigned int domain, unsigned int bus, >> unsigned int devfn, int reg, int len, u32 *val) >> { >> return pci_mmcfg_read(domain, bus, devfn, reg, len, val); >> } >> >> static inline int raw_pci_write(unsigned int domain, unsigned int bus, >> unsigned int devfn, int reg, int len, u32 val) >> { >> return pci_mmcfg_write(domain, bus, devfn, reg, len, val); >> } >> #endif > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- 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/