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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 90208C433F5 for ; Wed, 27 Apr 2022 20:46:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C7CAD6B0071; Wed, 27 Apr 2022 16:46:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C2B4E6B0073; Wed, 27 Apr 2022 16:46:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AF2356B0074; Wed, 27 Apr 2022 16:46:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.28]) by kanga.kvack.org (Postfix) with ESMTP id A0A8B6B0071 for ; Wed, 27 Apr 2022 16:46:25 -0400 (EDT) Received: from smtpin30.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 6883E2118E for ; Wed, 27 Apr 2022 20:46:25 +0000 (UTC) X-FDA: 79403841930.30.81C3416 Received: from mout.kundenserver.de (mout.kundenserver.de [217.72.192.73]) by imf30.hostedemail.com (Postfix) with ESMTP id 1DCA980060 for ; Wed, 27 Apr 2022 20:46:16 +0000 (UTC) Received: from mail-yw1-f179.google.com ([209.85.128.179]) by mrelayeu.kundenserver.de (mreue107 [213.165.67.113]) with ESMTPSA (Nemesis) id 1N64JK-1nuidK49KS-016Sym for ; Wed, 27 Apr 2022 22:46:23 +0200 Received: by mail-yw1-f179.google.com with SMTP id 00721157ae682-2f7d19cac0bso32153327b3.13 for ; Wed, 27 Apr 2022 13:46:22 -0700 (PDT) X-Gm-Message-State: AOAM530UhS+uDSHz0zsmpBmJg/koO2vE+5RU6BdITSFGx6QlSRWZRfTh eAvvS7HepaaF046RgSXyrOYkutXrSoW7obKsG4o= X-Google-Smtp-Source: ABdhPJxANmMoqAuHMC+ZEgkn1SQ7RkZSRhYC7mHz9ENipwBcb4dwpBkcMTggyEdiYrS6+jwmvudQ9Iia7DEbG1xmsXA= X-Received: by 2002:a81:9213:0:b0:2f6:eaae:d22f with SMTP id j19-20020a819213000000b002f6eaaed22fmr27226869ywg.249.1651092381529; Wed, 27 Apr 2022 13:46:21 -0700 (PDT) MIME-Version: 1.0 References: <20220427121413.168468-1-wangkefeng.wang@huawei.com> <20220427121413.168468-3-wangkefeng.wang@huawei.com> <20220427112545.3b8b9c46e5e5731b02394ace@linux-foundation.org> In-Reply-To: <20220427112545.3b8b9c46e5e5731b02394ace@linux-foundation.org> From: Arnd Bergmann Date: Wed, 27 Apr 2022 22:46:05 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 2/4] mm: ioremap: Add arch_ioremap/iounmap_check() To: Andrew Morton Cc: Arnd Bergmann , Kefeng Wang , Catalin Marinas , Will Deacon , Linux ARM , Linux Kernel Mailing List , Linux-MM Content-Type: text/plain; charset="UTF-8" X-Provags-ID: V03:K1:I3RJagO3LwqAAWbu3jR2DFvvBlauPuENdiFzlGwldjFVLOo76fk 05NH5tICDny2/B7vJBY0Jxkt4EjDY/2oj1LUEeJ5JvtKCoHJ2jlE7CqYO05eSuIS1DZhfw+ xLpG6GyraN1hzVj0kAQ253I/iSgR62S4FLGuhCHipV6VJn+hguEfwQ5VkSASRj+gtgZ9s5t Krv9+Kro46MKwT8qlTdcw== X-UI-Out-Filterresults: notjunk:1;V03:K0:pvER2/1CQDk=:BlX+VstvEhbqcBIy5fOKxd 3RRYzEpAgY8F9t97+KDsreYxPe5IZea9SkT66jZ+DDspUJBawTsACYRRtS7Be7KE035sRzkyu ySLqbRYmTcFHaOnkqQG6SAfIGsu9X0GcUkt08kcA1SpqmS/WK3MElXb1PxbxLrKHBmtWlZejq +5UgyZHkzvn8dnurYASklnAp7vOwQz/3/vnj4Kq7/nEwCakaHNjesOfYCCIRxutAJg7qXob2J vp9vycQykmjhZT/FUED34JpEfUn8HCx1isNrx9UHi2NqVpgbk6eEmvooJI41cTGC+pC6Q6ups YIc9nJiKwUzhSW8znVLlbMAyTImBTUk6y2CsTCqHUije4opiSg27Q0KPkqno7Cbwx3APVtvzG kCnalIIPhF3NQRtdvTe+6QLlWEnZw/JwdMNCGsxbLO7yEJ51KjtIPEajWC55BmW3DLjIDVpfK 4I/+1j0qfuAnUPtXqC4/C3ipID8pcyM9jHgRZLESimVgUyXssMI2hFSRMKK1hfBoYJrWI8NfE 6T5aaz8oOWsNaD5WapQZFAp0K9h8I4MIToJu/UtTPRGkNITJmxBBI+aXeneNY0Hlzr5JnRhTQ iS8122e8F52cNL2wP8jWVliPsdng/pyowo3FQxvqiL5SIFfoqRbgIAeXQRjWp7OBwxSQ2OSVJ BWScNFLaPUl+hARHnhdjyivh+KNfam/UB4JZAWpltdUy9D3kv1SpBYb1A4a3SCF3pUuW9sKRp rhBFe2qgoGQuvc1Ss6YCDimr8cRwHrptOZKVeg8CuX7oZUoqYRqi6h4O9U1wn7sxWPjFKreD8 UpaXBWX82qhwWh6VfF9sXVm7jIdmz4SgCkwM4l8kzXD3cAMZA8= X-Stat-Signature: 6w143u5c9jxgpzw4duy1jt8ojh1z9of6 Authentication-Results: imf30.hostedemail.com; dkim=none; spf=none (imf30.hostedemail.com: domain of arnd@arndb.de has no SPF policy when checking 217.72.192.73) smtp.mailfrom=arnd@arndb.de; dmarc=none X-Rspam-User: X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 1DCA980060 X-HE-Tag: 1651092376-441539 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Apr 27, 2022 at 8:25 PM Andrew Morton wrote: > On Wed, 27 Apr 2022 20:20:30 +0200 Arnd Bergmann wrote: > > On Wed, Apr 27, 2022 at 2:14 PM Kefeng Wang wrote: > > > > > > +bool __weak arch_ioremap_check(phys_addr_t addr, size_t size, unsigned long prot) > > > +{ > > > + return true; > > > +} > > > + > > > +bool __weak arch_iounmap_check(void __iomem *addr) > > > +{ > > > + return true; > > > +} > > > + > > > > I don't really like the weak functions. > > How come? They work quite nicely here? I find them rather confusing, mostly because it is less clear whether the fallback function is used in a given configuration, or a replacement one is present. This is a bigger problem in some subsystems than others, and the main place I don't like is the drivers/pci/ subsystem. A number of the uses there should be driver specific but happen to be implemented by architectures instead. Maybe I'm just projecting that onto other uses, but I definitely have a bad feeling about them here. Arnd