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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C9AA2CFB442 for ; Mon, 7 Oct 2024 06:32:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=CNZREUGhPVImGgBT4Uy1d6JfRz/d2TvUWGlKgbAP+hs=; b=ud/ZK9X0VEJt3R XTc9rByAhaIUPJ065VOGwXrPXaAKNiYhCtdgezH8zxCLLydS2zS15TRY+aPOvQDXushptYVsIV7PU xeamYdnFmnjLl6z6zinMpaa2uqQ3/3Wh+LL+kMhknZeKLwnp+pdGW3KlicDmXuac4bvCuFpxy4uzG 1eyqofG0dtnmPeCtnGELALHBXenvF2v9CfX8C0Dny5kGpcRRT8GoSm4MvuFx0swFlzoEQhKcpkofw CXVdriIaUu2L7pKGVo36XFaHOEZMt94G+Sh7AL1msTUirIFI6cqHbxKYUFUCZ12NH6bSANbApPwOQ Rdk/MJUKz9ItSz97t4mg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1sxhIQ-00000001RUW-2hsl; Mon, 07 Oct 2024 06:32:42 +0000 Received: from hch by bombadil.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1sxh8F-00000001PHa-12lh; Mon, 07 Oct 2024 06:22:11 +0000 Date: Sun, 6 Oct 2024 23:22:11 -0700 From: Christoph Hellwig To: Vladimir Kondratiev Cc: Christoph Hellwig , Alexandre Ghiti , Paul Walmsley , Palmer Dabbelt , Albert Ou , Andrew Morton , "linux-riscv@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" Subject: Re: [PATCH v1] riscv: make ZONE_DMA32 optional Message-ID: References: <20240827113611.537302-1-vladimir.kondratiev@mobileye.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Mon, Oct 07, 2024 at 06:17:14AM +0000, Vladimir Kondratiev wrote: > >Well, this doesn't get any more true by just irgnoring the previous > >discussion and just reposting :( > > Sorry, this wasn't the intention. Perhaps I messed with the message-id, I see my "patch v1" in one mail thread together with the previous discussion, but not in the other thread. > > Anyway, I think making ZONE_DMA32 selection depend on NONPORTABLE answers the concern > that was raised It doesn't at all. For one not having ZONE_DMA32 is going to break a lot of things. Drivers do expect 32-bit addressable memory. And because SOC designers know this there usually is a way to provide it, e.g. by doing window translations between cpu physical and bus physical address. Please go back to your data sheet or talk to the designers. And if there really is not way to provide this, the right way is just to stop the runtime allocation that triggered you to do this if ZONE_DMA32 is empty, not to add a non-portable option. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv