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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 C3AA0C27C4F for ; Tue, 18 Jun 2024 21:41:10 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4W3gDN1WZxz3cYV for ; Wed, 19 Jun 2024 07:41:08 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=145.40.73.55; helo=sin.source.kernel.org; envelope-from=cmarinas@kernel.org; receiver=lists.ozlabs.org) Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4W3gCx6xJPz2xcw for ; Wed, 19 Jun 2024 07:40:45 +1000 (AEST) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id A8C61CE1C9C; Tue, 18 Jun 2024 21:40:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E00DC3277B; Tue, 18 Jun 2024 21:40:41 +0000 (UTC) Date: Tue, 18 Jun 2024 22:40:39 +0100 From: Catalin Marinas To: Baruch Siach Subject: Re: [PATCH RFC v2 4/5] dma-direct: add base offset to zone_dma_bits Message-ID: References: <1d7b0d59590aae631b6f0b894257ab961b907b44.1712642324.git.baruch@tkos.co.il> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1d7b0d59590aae631b6f0b894257ab961b907b44.1712642324.git.baruch@tkos.co.il> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Rob Herring , linux-s390@vger.kernel.org, Ramon Fried , Saravana Kannan , devicetree@vger.kernel.org, Petr =?utf-8?B?VGVzYcWZw61r?= , Will Deacon , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, iommu@lists.linux.dev, Elad Nachman , Robin Murphy , Christoph Hellwig , linux-arm-kernel@lists.infradead.org, Marek Szyprowski Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Tue, Apr 09, 2024 at 09:17:57AM +0300, Baruch Siach wrote: > Current code using zone_dma_bits assume that all addresses range in the > bits mask are suitable for DMA. For some existing platforms this > assumption is not correct. DMA range might have non zero lower limit. [...] > @@ -59,7 +60,7 @@ static gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 *phys_limit) > * zones. > */ > *phys_limit = dma_to_phys(dev, dma_limit); > - if (*phys_limit <= zone_dma_limit) > + if (*phys_limit <= zone_dma_base + zone_dma_limit) > return GFP_DMA; > if (*phys_limit <= DMA_BIT_MASK(32)) > return GFP_DMA32; As I said previously, we no longer have zone_dma_bits after the first patch, so adding this limit no longer make sense. In v1, you wanted a limit like 32G to be added to the 30-bit zone_dma_bits to give you 33G upper limit for ZONE_DMA. But since the first patch sets zone_dma_limit to 33G already, this is no longer needed. -- Catalin