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 BC36CC43334 for ; Wed, 29 Jun 2022 15:56:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234414AbiF2P4f (ORCPT ); Wed, 29 Jun 2022 11:56:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36302 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234353AbiF2P4A (ORCPT ); Wed, 29 Jun 2022 11:56:00 -0400 Received: from mail-qv1-f50.google.com (mail-qv1-f50.google.com [209.85.219.50]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 48B07134; Wed, 29 Jun 2022 08:55:21 -0700 (PDT) Received: by mail-qv1-f50.google.com with SMTP id p31so25424493qvp.5; Wed, 29 Jun 2022 08:55:21 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=OEMWl4TCJsTuvIttBxj/Eh5iikDl97HkNRqb1XE+j6I=; b=Xg9/YCWcU4HCNPDh3EPOzGHpXtzEi7mpKF5PiPd+SQAPwzbtlALvkbvsmc9gh3JnkU jLnSTa8DCeWjOt0+4rrp8p35z7wvofM/Xuc42LfadBRvanAFCKBbfjRT/OFhgF1xVp0h zMXM6hwn8kzn9TbUExMnC/YASISp7Ve/1/tOUafQZsUX8zZi+J2wbxXau3oGYD0+t6tk Y8jDGNvPM6ObB0w+p2qYf9p/YAhOgSDR/LoCApMMzegNPsm16fpndBOyimK5B+8jAkzC FQDrbqBak6kpMZ+djl83yNawQPEwFRqEiElPlPZwP84ZNdg8SmQywc+Wxhnf5Ia8Yhsl ODlw== X-Gm-Message-State: AJIora/wkb2v7+peFgvoV9n88bI2a+9gaPHmIUbHsiN+W9YlewDutTlj tNjVi9jawcGZy4xf4sdOOTzorNKXvsEhOQ== X-Google-Smtp-Source: AGRyM1sGCveBJqtg69EAI42VcwKhljvdWxn1cOFZ2qy6sttieQ1GEAcYwK1JyauHwHWiirbLPXEUiA== X-Received: by 2002:a05:6214:f65:b0:470:3e5a:e523 with SMTP id iy5-20020a0562140f6500b004703e5ae523mr7348506qvb.128.1656518120104; Wed, 29 Jun 2022 08:55:20 -0700 (PDT) Received: from mail-yb1-f172.google.com (mail-yb1-f172.google.com. [209.85.219.172]) by smtp.gmail.com with ESMTPSA id s11-20020a05622a1a8b00b003196e8eda26sm5667690qtc.69.2022.06.29.08.55.19 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 29 Jun 2022 08:55:19 -0700 (PDT) Received: by mail-yb1-f172.google.com with SMTP id i15so28814890ybp.1; Wed, 29 Jun 2022 08:55:19 -0700 (PDT) X-Received: by 2002:a5b:6c1:0:b0:669:a7c3:4c33 with SMTP id r1-20020a5b06c1000000b00669a7c34c33mr4124902ybq.543.1656518119387; Wed, 29 Jun 2022 08:55:19 -0700 (PDT) MIME-Version: 1.0 References: <20220629011638.21783-1-schmitzmic@gmail.com> <20220629011638.21783-3-schmitzmic@gmail.com> <554d6fa7-01b7-d3c8-a72a-6474e9c5038e@gmail.com> In-Reply-To: <554d6fa7-01b7-d3c8-a72a-6474e9c5038e@gmail.com> From: Geert Uytterhoeven Date: Wed, 29 Jun 2022 17:55:07 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v1 2/3] scsi - a2091.c: convert m68k WD33C93 drivers to DMA API To: Michael Schmitz Cc: Arnd Bergmann , "Linux/m68k" , linux-scsi Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Hi Michael, On Wed, Jun 29, 2022 at 9:27 AM Michael Schmitz wrote: > Most users will opt for loading the kernel to a RAM chunk at a higher > physical address, making the lower chunk unusable (except as chip RAM), > meaning allocating a bounce buffer within the first 16 MB will most > likely fail anyway AIUI (but Geert would know that for sure). Exactly. On Zorro III-capable machines, Zorro II RAM is not mapped for general use, but can be used by the z2ram block device. Note that you can use it as a bounce buffer, by looking for and marking free chunks in the zorro_unused_z2ram bitmap. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds