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=-10.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 5B091C64EB4 for ; Fri, 30 Nov 2018 13:23:25 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 2D6B32080A for ; Fri, 30 Nov 2018 13:23:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Bi39u3/x" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2D6B32080A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=3EZaeq5zRyc71UCqk47EwU8V6dxQN8e1AYmcB/SwEII=; b=Bi39u3/xuMhssj KoeBvs6ZUpwQZ4bQAw0/OBd4xuzkIRw4nPsKOmMbbcu5mJ14Ne+VE0XD6Z8suKrMhA/9021r5H8jQ tGYkMEeB/5DhiUaQfyLngScm97LBwUCuYaIjsT+d4XeyU746GZZDnxm2SVdZxd+hITQoLYTyKE+FN o5vcR7pSOKoBtYMSRcup1X+n6peTUpmByRxhUN4uNSc6bu0uftAYtDD2/u4iCExD+PQZS4cnL8RK3 li4S6je+tygsbZZH9BpYG/3d/9VvnZLA0s1CXvq4GPYuBvQny5F+cWul/HCI8ggZ3m0o9mtVVUAbQ yvHDwJJPADABon+1H9qA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gSilP-0004Xj-C3; Fri, 30 Nov 2018 13:23:23 +0000 Received: from 089144206221.atnat0015.highway.bob.at ([89.144.206.221] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gSil4-0004Gu-6E; Fri, 30 Nov 2018 13:23:02 +0000 From: Christoph Hellwig To: iommu@lists.linux-foundation.org Subject: [PATCH 01/23] dma-mapping: provide a generic DMA_MAPPING_ERROR Date: Fri, 30 Nov 2018 14:22:09 +0100 Message-Id: <20181130132231.16512-2-hch@lst.de> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181130132231.16512-1-hch@lst.de> References: <20181130132231.16512-1-hch@lst.de> MIME-Version: 1.0 X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, linux-alpha@vger.kernel.org, linux-ia64@vger.kernel.org, linux-parisc@vger.kernel.org, Linus Torvalds , Joerg Roedel , x86@kernel.org, Robin Murphy , linux-kernel@vger.kernel.org, Jon Mason , xen-devel@lists.xenproject.org, David Woodhouse , linux-arm-kernel@lists.infradead.org, Marek Szyprowski Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Error handling of the dma_map_single and dma_map_page APIs is a little problematic at the moment, in that we use different encodings in the returned dma_addr_t to indicate an error. That means we require an additional indirect call to figure out if a dma mapping call returned an error, and a lot of boilerplate code to implement these semantics. Instead return the maximum addressable value as the error. As long as we don't allow mapping single-byte ranges with single-byte alignment this value can never be a valid return. Additionaly if drivers do not check the return value from the dma_map* routines this values means they will generally not be pointed to actual memory. Once the default value is added here we can start removing the various mapping_error methods and just rely on this generic check. Signed-off-by: Christoph Hellwig --- include/linux/dma-mapping.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 0f81c713f6e9..46bd612d929e 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -133,6 +133,8 @@ struct dma_map_ops { u64 (*get_required_mask)(struct device *dev); }; +#define DMA_MAPPING_ERROR (~(dma_addr_t)0) + extern const struct dma_map_ops dma_direct_ops; extern const struct dma_map_ops dma_virt_ops; @@ -576,6 +578,10 @@ static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr) const struct dma_map_ops *ops = get_dma_ops(dev); debug_dma_mapping_error(dev, dma_addr); + + if (dma_addr == DMA_MAPPING_ERROR) + return 1; + if (ops->mapping_error) return ops->mapping_error(dev, dma_addr); return 0; -- 2.19.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel