From patchwork Wed Dec 13 17:17:55 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robin Murphy X-Patchwork-Id: 13491679 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 4FF22C4167D for ; Wed, 13 Dec 2023 17:19:05 +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:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=MuYpB2Dik1/e0PTFEEO3+sB4GlQ0UqOU7yVLOQgH7UQ=; b=D2vm9X3RE0xu2y ggecWlVWOElR/4+iorb18spfk9OlbBXaf/hAnZMWFhIGyVYxoXLytUCOJ1QHOp9OjEvHxIcYCgCVA ubc6rHJvL/jJb1otPIWVIfBa2h1b1Z8XYKSl/IR6DEJCnE1NOdlKkUfhLFoVKK6mBenNah1qf3pTB fV9qVvJuv3IRvXgsXxONXaASxPpwhWSamUIHC8zqvnfdcgKzW/oOKxToUXGkLdwCndW6mxQt49MyN nY7A1minCwnK0+hB2PYmGhdpnJpHH5FWgk+CsV1m9IFsmPSddKlTN5HvsWXw0+TtLFNibHSRObToM zOPWnrXwfjCoQg2e0yiw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rDSsY-00FZJu-0j; Wed, 13 Dec 2023 17:18:38 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rDSsS-00FZGY-0u for linux-arm-kernel@lists.infradead.org; Wed, 13 Dec 2023 17:18:33 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3E9621576; Wed, 13 Dec 2023 09:19:16 -0800 (PST) Received: from e121345-lin.cambridge.arm.com (e121345-lin.cambridge.arm.com [10.1.196.40]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 1B3323F762; Wed, 13 Dec 2023 09:18:26 -0800 (PST) From: Robin Murphy To: Joerg Roedel , Christoph Hellwig Cc: Vineet Gupta , Russell King , Catalin Marinas , Will Deacon , Huacai Chen , WANG Xuerui , Thomas Bogendoerfer , Paul Walmsley , Palmer Dabbelt , Albert Ou , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Suravee Suthikulpanit , David Woodhouse , Lu Baolu , Niklas Schnelle , Matthew Rosato , Gerald Schaefer , Jean-Philippe Brucker , Rob Herring , Frank Rowand , Marek Szyprowski , Jason Gunthorpe , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org, iommu@lists.linux.dev, devicetree@vger.kernel.org, Rob Herring , Jason Gunthorpe Subject: [PATCH v2 2/7] OF: Simplify DMA range calculations Date: Wed, 13 Dec 2023 17:17:55 +0000 Message-Id: <368a546e36235bd0008f66838d0c8edcd864ab94.1702486837.git.robin.murphy@arm.com> X-Mailer: git-send-email 2.39.2.101.g768bb238c484.dirty In-Reply-To: References: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231213_091832_413056_5D1B75DA X-CRM114-Status: GOOD ( 14.66 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Juggling start, end, and size values for a range is somewhat redundant and a little hard to follow. Consolidate down to just using inclusive start and end, which saves us worrying about size overflows for full 64-bit ranges (note that passing a potentially-overflowed value through to arch_setup_dma_ops() is benign for all current implementations, and this is working towards removing that anyway). Acked-by: Rob Herring Reviewed-by: Jason Gunthorpe Signed-off-by: Robin Murphy --- drivers/of/device.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) diff --git a/drivers/of/device.c b/drivers/of/device.c index 526a42cdf66e..51062a831970 100644 --- a/drivers/of/device.c +++ b/drivers/of/device.c @@ -97,7 +97,7 @@ int of_dma_configure_id(struct device *dev, struct device_node *np, const struct bus_dma_region *map = NULL; struct device_node *bus_np; u64 dma_start = 0; - u64 mask, end, size = 0; + u64 mask, end = 0; bool coherent; int ret; @@ -118,17 +118,15 @@ int of_dma_configure_id(struct device *dev, struct device_node *np, return ret == -ENODEV ? 0 : ret; } else { const struct bus_dma_region *r = map; - u64 dma_end = 0; /* Determine the overall bounds of all DMA regions */ for (dma_start = ~0; r->size; r++) { /* Take lower and upper limits */ if (r->dma_start < dma_start) dma_start = r->dma_start; - if (r->dma_start + r->size > dma_end) - dma_end = r->dma_start + r->size; + if (r->dma_start + r->size > end) + end = r->dma_start + r->size; } - size = dma_end - dma_start; } /* @@ -142,16 +140,15 @@ int of_dma_configure_id(struct device *dev, struct device_node *np, dev->dma_mask = &dev->coherent_dma_mask; } - if (!size && dev->coherent_dma_mask) - size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); - else if (!size) - size = 1ULL << 32; + if (!end && dev->coherent_dma_mask) + end = dev->coherent_dma_mask; + else if (!end) + end = (1ULL << 32) - 1; /* * Limit coherent and dma mask based on size and default mask * set by the driver. */ - end = dma_start + size - 1; mask = DMA_BIT_MASK(ilog2(end) + 1); dev->coherent_dma_mask &= mask; *dev->dma_mask &= mask; @@ -177,7 +174,7 @@ int of_dma_configure_id(struct device *dev, struct device_node *np, dev_dbg(dev, "device is%sbehind an iommu\n", iommu ? " " : " not "); - arch_setup_dma_ops(dev, dma_start, size, iommu, coherent); + arch_setup_dma_ops(dev, dma_start, end - dma_start + 1, iommu, coherent); if (!iommu) of_dma_set_restricted_buffer(dev, np);