From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 45498C433EF for ; Mon, 23 May 2022 03:58:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355597AbiEWD6O (ORCPT ); Sun, 22 May 2022 23:58:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37666 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353324AbiEWD6C (ORCPT ); Sun, 22 May 2022 23:58:02 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id F1DC624F3E for ; Sun, 22 May 2022 20:58:00 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 94B0C113E; Sun, 22 May 2022 20:58:00 -0700 (PDT) Received: from [10.163.36.114] (unknown [10.163.36.114]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7A5223F66F; Sun, 22 May 2022 20:57:56 -0700 (PDT) Message-ID: Date: Mon, 23 May 2022 09:27:57 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH v3 4/6] mm: ioremap: Add arch_ioremap/iounmap() Content-Language: en-US To: Andrew Morton , Kefeng Wang Cc: catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, hch@infradead.org, arnd@arndb.de References: <20220519082552.117736-1-wangkefeng.wang@huawei.com> <20220519082552.117736-5-wangkefeng.wang@huawei.com> <20220519115210.a6e41d5a997921354400557e@linux-foundation.org> From: Anshuman Khandual In-Reply-To: <20220519115210.a6e41d5a997921354400557e@linux-foundation.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/20/22 00:22, Andrew Morton wrote: > On Thu, 19 May 2022 16:25:50 +0800 Kefeng Wang wrote: > >> Add special hook for architecture to verify or setup addr, size >> or prot when ioremap() or iounmap(), which will make the generic >> ioremap more useful. >> >> arch_ioremap() return a pointer, >> - IS_ERR means return an error >> - NULL means continue to remap >> - a non-NULL, non-IS_ERR pointer is directly returned >> arch_iounmap() return a int value, >> - 0 means continue to vunmap >> - error code means skip vunmap and return directly >> >> ... >> >> --- a/include/asm-generic/io.h >> +++ b/include/asm-generic/io.h >> @@ -964,6 +964,30 @@ static inline void iounmap(volatile void __iomem *addr) >> #elif defined(CONFIG_GENERIC_IOREMAP) >> #include >> >> +/* >> + * Arch code can implement the following two special hooks when using GENERIC_IOREMAP >> + * arch_ioremap() return a pointer, >> + * - IS_ERR means return an error >> + * - NULL means continue to remap >> + * - a non-NULL, non-IS_ERR pointer is returned directly >> + * arch_iounmap() return a int, >> + * - 0 means continue to vunmap >> + * - error code means skip vunmap and return directly >> + */ >> +#ifndef arch_ioremap >> +static inline void __iomem *arch_ioremap(phys_addr_t phys_addr, size_t size, unsigned long prot) >> +{ >> + return NULL; >> +} > > Maybe should do > > #define arch_ioremap arch_ioremap > > here > >> +#endif >> + >> +#ifndef arch_iounmap >> +static inline int arch_iounmap(void __iomem *addr) >> +{ >> + return 0; >> +} > > and here. > > It shouldn't matter a lot because this file has inclusion guards. > However it seems tidier and perhaps other code will want to know > whether this was defined. Dunno. +1, agreed.