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=-0.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS autolearn=no 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 2E9B5C4332D for ; Mon, 4 Jan 2021 16:09:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F34D7205CA for ; Mon, 4 Jan 2021 16:09:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728530AbhADQBQ (ORCPT ); Mon, 4 Jan 2021 11:01:16 -0500 Received: from mout.gmx.net ([212.227.17.22]:39545 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728511AbhADQBN (ORCPT ); Mon, 4 Jan 2021 11:01:13 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1609775978; bh=8dYzMDBKUF2sybRjESev4F3J9T3mj+pyYPcEcjGHCf0=; h=X-UI-Sender-Class:Date:From:To:Cc:Subject:In-Reply-To:References; b=kELxTBswtIVyJ+/QfJtofwtpyWUkgh8sQIcONLr0RSeHwA6LsLkGeCeeczzzLhW2/ WnhYIt3QoGXS8+S91ti8EUirg6RcSQJ/eFB4lv/Sbm+YIoEDuQWgZ7rLeSgmgLXMYo KVcaFpOjTsyHMXOtp2aLLx/UCyvh51NexF9NSUzs= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from Valinor ([82.128.181.212]) by mail.gmx.com (mrgmx104 [212.227.17.174]) with ESMTPSA (Nemesis) id 1MNKhm-1kc9AJ3B18-00Omz7; Mon, 04 Jan 2021 16:59:37 +0100 Date: Mon, 4 Jan 2021 18:01:15 +0200 From: Lauri Kasanen To: Keith Busch Cc: linux-mips@vger.kernel.org, tsbogend@alpha.franken.de, axboe@kernel.dk, linux-block@vger.kernel.org Subject: Re: [PATCH 6/6] block: Add n64 cart driver Message-Id: <20210104180115.b1d5438cd4ee21efcd557976@gmx.com> In-Reply-To: <20210104154902.GA1024941@dhcp-10-100-145-180.wdc.com> References: <20210104155031.9b4e39ff48a6d7accc93461d@gmx.com> <20210104154902.GA1024941@dhcp-10-100-145-180.wdc.com> X-Mailer: Sylpheed 3.5.0 (GTK+ 2.18.6; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:6uClOfvhWTGJ72YP4IUDfeJ1Nt2MWOpuMIY8iNkoeeUNdt/xJYF a+RuIY4ryesoovh6UA69IdknEeTEs/V6r4IpqXMG5w7dj5ujOjEmojwzgrWulg3q9RDfAyP Edcvyg3QfcinkNwaNucBPvycXSFsR8dKQm3eg18dRCObIlvqJhXTM/fzZrGl7BMqFNNG7b5 q5leAjr5k03tZQ06L4eBA== X-UI-Out-Filterresults: notjunk:1;V03:K0:8TcCjfE8g28=:MzQilyLcksyyXW8U9Ia++S fV2njqadX7eiT3kJQS2nI+lGkFrxkxl38HrNhJlitJWSl6gqu5gyL25tRMPoyEYDfUMUTZvFw SnKoIV3c6wiLwsw3j7Wz2N4b1k2R28/7kSjhxp9J78A6J3lqpW5cdaqf+GqXMce8ejJnjTyR7 WGacmzXlzbdcqB58YL2xQ2Aas2+3jKIAN6dkvXOQ6/OLX0SHG+UXmBd/5GDNcRg70IZVElNVx 4rcjIQLIjUg8Xncd4w61/RNq00xP8iLFRm5+aKWRHVbb5fMmztmfTKvpFouWzmqgy51VGeG4r SjXwbuIbzH+qBTFqMjQvjQEhVY2NmTVBMCKptita7SKIUjlYRXZxgMXnYH/3y0jQkGOec7nbT 5FccdWdBnUeniu49YWzbqB9gpPR0OdwkOa12tz6X7yipXEwq1k0WEbFnZ22tOw1nKT4eytAHe Rwzrt11xgWtBJJuWFIItNok6UUlb7Vo1LUG9yenlbAC42wKO70qbH6UQCDfNNnRF6WJIGCNnS 2CR7W1xG5n9pzAdSQJcHpCSvwTnVgHLt+U1yY3/VFMDkQ2fTTMvrjGha4p7c4FwiuJ/7+EzKP UgCCDNl4GZ31BnoMdtc/DaB7tvrUg2akoe8445khTIkpwo2OTRSgDRInomF/olbDAt5C0amxV Xn+est2kYdsOHukG7+7Ax2oRaakLZ0iodokWLMLZ1bQfi1E27+aSsObzCnnL3Tz+howpf2gVG sENRy+V+5SLPSIIBUMzY3PQb7pTdFZfVLXpzqbnC4mrz9Qd2jgefaRkKIDI0MR6Y+7B9mVhGy 5Wy24Q5qCCItHVax8kyp0GKRXUTz+AilEWpMiLjaI0bTKTUM9qNpPSCH7LX4wnLlPDHNAGRbO wgtZWxhdz+bP+WmTZAvQ== Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Mon, 4 Jan 2021 07:49:02 -0800 Keith Busch wrote: > On Mon, Jan 04, 2021 at 03:50:31PM +0200, Lauri Kasanen wrote: > > block folks: rest of the series is on linux-mips. Being a mips-specifi= c driver, > > not sure which tree it should go to. > > Probably through mips. Thanks. > > +static blk_status_t get_seg(struct request *req) > > +{ > > + u32 bstart =3D blk_rq_pos(req) * 512; > > + u32 len =3D blk_rq_cur_bytes(req); > > + void *dst =3D bio_data(req->bio); > > + > > + if (bstart + len > size || rq_data_dir(req) =3D=3D WRITE) > > + return BLK_STS_IOERR; > > If you don't support writes (is that limitation temporary?), then you > can prevent such operations from reaching the driver by setting the > "disk" to read-only during initialization with set_disk_ro(disk, true). The media is read-only (but not runtime removable). > > +static int __init n64cart_init(void) > > +{ > > + int err; > > + > > + if (!start || !size) { > > + pr_err("n64cart: start and size not specified\n"); > > + return -ENODEV; > > + } > > Just curious, is it not possible to discover these values from the > installed cart? Requiring module parameters seems a bit fragile. No, it's not possible. Even the cart's size is not discoverable, and where the disk image starts and how long it is could only be scanned if you knew in advance what FS what used, etc. There is no FS on the cart itself, it's just raw data. The bootloader embeds these values into itself when it's built. - Lauri