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 X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 33CA6C54FD0 for ; Mon, 27 Apr 2020 10:43:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 192D120575 for ; Mon, 27 Apr 2020 10:43:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727060AbgD0Knw (ORCPT ); Mon, 27 Apr 2020 06:43:52 -0400 Received: from lhrrgout.huawei.com ([185.176.76.210]:2111 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726537AbgD0Knv (ORCPT ); Mon, 27 Apr 2020 06:43:51 -0400 Received: from lhreml724-chm.china.huawei.com (unknown [172.18.7.107]) by Forcepoint Email with ESMTP id 1A5E68E417FCE3EC8A7D; Mon, 27 Apr 2020 11:43:50 +0100 (IST) Received: from [127.0.0.1] (10.210.170.137) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1913.5; Mon, 27 Apr 2020 11:43:47 +0100 Subject: Re: [PATCH 3/4] lib: logic_pio: Introduce MMIO_LOWER_RESERVED To: Jiaxun Yang , CC: Thomas Bogendoerfer , Huacai Chen , Paul Burton , Thomas Gleixner , Stephen Kitt , Nick Desaulniers , Serge Semin , Anshuman Khandual , Geert Uytterhoeven , Andrew Morton , Daniel Silsby , Mike Rapoport , Paul Cercueil , Mark Tomlinson , Greg Kroah-Hartman , Allison Randal , Tiezhu Yang , Wei Xu , , Arnd Bergmann , Linuxarm , Bjorn Helgaas , Rob Herring References: <20200426114806.1176629-1-jiaxun.yang@flygoat.com> <20200426114806.1176629-4-jiaxun.yang@flygoat.com> From: John Garry Message-ID: Date: Mon, 27 Apr 2020 11:43:09 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: <20200426114806.1176629-4-jiaxun.yang@flygoat.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.210.170.137] X-ClientProxiedBy: lhreml722-chm.china.huawei.com (10.201.108.73) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On 26/04/2020 12:47, Jiaxun Yang wrote: > That would allow platforms reserve some lower address in PIO MMIO range > to deal with legacy drivers with hardcoded I/O ports that can't be > managed by logic_pio. Hi, Is there some reason why the logic_pio code cannot be improved to handle these devices at these "fixed" addresses? Or do you have a plan to improve it? We already support fixed bus address devices in the INDIRECT IO region. Carving out a region of IO space is less than ideal. Thanks, John > > Signed-off-by: Jiaxun Yang > --- > lib/logic_pio.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/lib/logic_pio.c b/lib/logic_pio.c > index f511a99bb389..57fff1cb7063 100644 > --- a/lib/logic_pio.c > +++ b/lib/logic_pio.c > @@ -20,6 +20,10 @@ > static LIST_HEAD(io_range_list); > static DEFINE_MUTEX(io_range_mutex); > > +#ifndef MMIO_LOWER_RESERVED > +#define MMIO_LOWER_RESERVED 0 > +#endif > + > /* Consider a kernel general helper for this */ > #define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len)) > > @@ -36,7 +40,7 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range) > struct logic_pio_hwaddr *range; > resource_size_t start; > resource_size_t end; > - resource_size_t mmio_end = 0; > + resource_size_t mmio_end = MMIO_LOWER_RESERVED; > resource_size_t iio_sz = MMIO_UPPER_LIMIT; > int ret = 0; > >