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 C0D6FC433EF for ; Tue, 24 May 2022 12:38:01 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4BFCB8D0003; Tue, 24 May 2022 08:38:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 46ED58D0002; Tue, 24 May 2022 08:38:01 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3874C8D0003; Tue, 24 May 2022 08:38:01 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 2B8A88D0002 for ; Tue, 24 May 2022 08:38:01 -0400 (EDT) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id EF4D461464 for ; Tue, 24 May 2022 12:38:00 +0000 (UTC) X-FDA: 79500588720.10.497BBC5 Received: from mout.kundenserver.de (mout.kundenserver.de [212.227.126.130]) by imf06.hostedemail.com (Postfix) with ESMTP id EED59180034 for ; Tue, 24 May 2022 12:37:56 +0000 (UTC) Received: from mail-yw1-f178.google.com ([209.85.128.178]) by mrelayeu.kundenserver.de (mreue010 [213.165.67.97]) with ESMTPSA (Nemesis) id 1MofPt-1nVRVv2GV7-00p2QA for ; Tue, 24 May 2022 14:37:58 +0200 Received: by mail-yw1-f178.google.com with SMTP id 00721157ae682-30007f11f88so48465657b3.7 for ; Tue, 24 May 2022 05:37:58 -0700 (PDT) X-Gm-Message-State: AOAM533IdzJTCv4OFgVA7BQW9V+XIruohSVJCpyC3AM4vsKodBuebQcS 4AQcF0/gx9i1AE4Q98VRxZSaWE6YrIA2PosRNNk= X-Google-Smtp-Source: ABdhPJx+pOz2MDU2NITSHyjL28/g5r+nN7bHb7KpfKqjLOGOqmggd/HyMXX1mE/rep3OWY+xalb+HtpnZq+e2n5DUFQ= X-Received: by 2002:a0d:cfc7:0:b0:300:26d2:30eb with SMTP id r190-20020a0dcfc7000000b0030026d230ebmr3208573ywd.320.1653395877066; Tue, 24 May 2022 05:37:57 -0700 (PDT) MIME-Version: 1.0 References: <20220519082552.117736-1-wangkefeng.wang@huawei.com> <20220519082552.117736-5-wangkefeng.wang@huawei.com> In-Reply-To: <20220519082552.117736-5-wangkefeng.wang@huawei.com> From: Arnd Bergmann Date: Tue, 24 May 2022 14:37:40 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v3 4/6] mm: ioremap: Add arch_ioremap/iounmap() To: Kefeng Wang Cc: Catalin Marinas , Will Deacon , Andrew Morton , Linux ARM , Linux Kernel Mailing List , Linux-MM , Christoph Hellwig , Arnd Bergmann , Anshuman Khandual Content-Type: text/plain; charset="UTF-8" X-Provags-ID: V03:K1:6j8ZJQiYgbVxfxUAyJBV4JP669ijYSYjVm+pLRbjNksrx+//7zG oFputS9UtMxWzMNQhIfoVLYPQne25mH96+prhozPLgCCxXJyy2LnyrGZR7zZ+XNx8W3+7uC djkJJt/+85/VvEt0ZPcU8KYv3HjSwLOG8OQ3422LHZjEgpmbu0GmxaYSllQQ6wUClqklVa3 E9lPbEsPesvWD54cb1fyQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:fpDrIWp/B9s=:7LXg3AhinQZobWeEiWajcD dTvm+beqSCnEpYywp6RLkMiM7lXBeVhcgOzuYCy71+Uc2Kfn9FGtfq5EQdO0KQS1VDhXX7dL4 ANJZwcXUC4TWY/uuvy5/ctcFElMi9PJHLsL930NHV5y8rThE9bvP8HCUNScFylWCZ2OnrLnRp ydgIdK3G9gRphoIQlFFO3HM8dNAfvVMZwKolxVffoPdlkcNDgW2Kfrb79EjflJwazEJkXpzwY NqpLUaxJtvKaYT6ew1sGsl2Nvxk5QbUil6QFmMbM6KMRtZZPfrVKZ4LzQtIrilrhajwxEhclT apj/YKPHo8mmyW+WZ0NoihtSx9++lowc0v6GZRNRkRCGDkpPctLxCP0fBMGfLju4MBYYyY5+r mTnMpLmMcGI04javaqDuHN0z3jZd07hXH70knTTax5Mvy/nP4MWHip5FIGlBAV8ugs8nq0+Lw 4jG/RWalxMV30T5jufoZnEYqgOd+qV/ut40NpBE5c/4Z5H1uFKuhZ466Ou/f8DDrXJU6mIsr5 yJOhAKVePPq3Awrfz0ZBB4XmPc42QlI8K8hV2GC4SoBmfnlJXKkUeNnyPPy0GFuvnQHD0aRkG 2OM4tkrNlkCyFBon3Npe/VrbEKPUNAI9nOHrMRQgYvMsUgznFSiMUedXNoiZ0BIClGxraDTQ6 Aii+4YIIyEH2gifDNk9rvQWa5vVFsm/1TmnO0DoKO+tJEiQJ3ATrGJF8xGsSIkWZG9/w/gUEq 2+EgunXUuRcwPwYd++rnpFUOZpi9fOkz6W7LFIuK8i7qXTnNl3Ty/10TzhYK5fcxAfKOQ8CVT eQnJ2URNVhXFb/pPwUBBX6T8gyY6k75YgVka+thOsCTa5r52U5a8CyaKsgAow/Yfo5JzJ3Pu6 H12paJctd+PtEtYkuK2g== X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: EED59180034 X-Stat-Signature: aeiir7gwy16m71z34si8tscwhutye6u1 Authentication-Results: imf06.hostedemail.com; dkim=none; dmarc=none; spf=none (imf06.hostedemail.com: domain of arnd@arndb.de has no SPF policy when checking 212.227.126.130) smtp.mailfrom=arnd@arndb.de X-Rspam-User: X-HE-Tag: 1653395876-915017 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 Thu, May 19, 2022 at 10:25 AM 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 > > Signed-off-by: Kefeng Wang I don't really like interfaces that mix error pointers and NULL pointer returns. Would it be possible to have a special error code other than NULL for the fallback case? arnd