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=-3.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT autolearn=ham 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 79222C282C3 for ; Tue, 22 Jan 2019 09:23:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 40651218DA for ; Tue, 22 Jan 2019 09:23:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548149006; bh=tvfSfixV9M/zFUAZ25eiE9ftJmocefhGyeG7bJ1p+wc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=ckMnl0X+i/Uoz4hPBZ/ia3WUMIvC/G6DP8IBwxPvHitA0R6p28xZcJzy/ISark6fP 1DfM5h68n0WWlzycRY0mnFCCL6V/Xc/r8T23qA9xKtGTItnhouSMka/LLVkxqXHgUC cS/za9bR4FvO0BBGRAbpbUZPUGm4EpjXz5jG0SU4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727730AbfAVJXY (ORCPT ); Tue, 22 Jan 2019 04:23:24 -0500 Received: from mail.kernel.org ([198.145.29.99]:47216 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727509AbfAVJXX (ORCPT ); Tue, 22 Jan 2019 04:23:23 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E8847218D4; Tue, 22 Jan 2019 09:23:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548149002; bh=tvfSfixV9M/zFUAZ25eiE9ftJmocefhGyeG7bJ1p+wc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=FiR3edAXBVFUN7hzroBaOdWPtGHJ4PvajGPuamdx3G45qsVh4pQCSBGYHxHhWCvGG UcxdFStjA+N+NgMGE/+jFBsRbGP+55MuNl0zqtSVFzpqWRf+oOcWl4sK+Qh8NEzL9d 5uAQ8uVHQZ3QkihfTDVeHr2RmnOHtQsEHcXatTxU= Date: Tue, 22 Jan 2019 10:22:34 +0100 From: Greg Kroah-Hartman To: Finn Thain Cc: Arnd Bergmann , "James E.J. Bottomley" , "Martin K. Petersen" , Michael Schmitz , Geert Uytterhoeven , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Bartlomiej Zolnierkiewicz , Joshua Thompson , linux-kernel@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linuxppc-dev@lists.ozlabs.org, linux-scsi@vger.kernel.org, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: Re: [PATCH v9 00/22] Re-use nvram module Message-ID: <20190122092234.GA15813@kroah.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.2 (2019-01-07) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 15, 2019 at 03:18:56PM +1100, Finn Thain wrote: > The "generic" NVRAM module, drivers/char/generic_nvram.c, implements a > /dev/nvram misc device. This module is used only by 32-bit PowerPC > platforms. > > The RTC "CMOS" NVRAM module, drivers/char/nvram.c, also implements a > /dev/nvram misc device. This module is now used only by x86 and m68k > thanks to commit 3ba9faedc180 ("char: nvram: disable on ARM"). > > The "generic" module cannot be used by x86 or m68k platforms because it > cannot co-exist with the "CMOS" module. One reason for that is the > CONFIG_GENERIC_NVRAM kludge in drivers/char/Makefile. Another reason is > that automatically loading the appropriate module would be impossible > because only one module can provide the char-major-10-144 alias. > > A multi-platform kernel binary needs a single, generic module. With this > patch series, drivers/char/nvram.c becomes more generic and some of the > arch-specific code gets moved under arch/. The nvram module is then > usable by all m68k, powerpc and x86 platforms. > > This allows for removal of drivers/char/generic_nvram.c as well as a > duplicate in arch/powerpc/kernel/nvram_64.c. By reducing the number of > /dev/nvram char misc device implementations, the number of bugs and > inconsistencies is also reduced. > > This approach reduces inconsistencies between PPC32 and PPC64 and also > between PPC_PMAC and MAC. A uniform API has benefits for userspace. > > For example, some error codes for some ioctl calls become consistent > across PowerPC platforms. The uniform API can potentially benefit any > bootloader that works across the various platforms having XPRAM > (e.g. Emile). > > This patch series was tested on Atari, Mac, PowerMac (both 32-bit and > 64-bit) and ThinkPad hardware. AFAIK, it has not yet been tested on > pSeries or CHRP. > > I think there are two possible merge strategies for this patch series. > The char misc maintainer could take the entire series. Alternatively, > the m68k maintainer could take patches 1 thru 16 (though some of these > have nothing to do with m68k) and after those patches reach mainline > the powerpc maintainer could take 17 thru 22. I just took the whole series, thanks for doing this, looks good. greg k-h