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=-8.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 E51D7C43441 for ; Thu, 22 Nov 2018 14:06:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ADCAE20684 for ; Thu, 22 Nov 2018 14:06:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="liIeK+xP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ADCAE20684 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-parisc-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2395332AbeKWAnL (ORCPT ); Thu, 22 Nov 2018 19:43:11 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:55286 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2395350AbeKWAnL (ORCPT ); Thu, 22 Nov 2018 19:43:11 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From :Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=b0mTsSZ7pnWLHYe0tv9bLnm4xmcVv2T1rI2O6B8DMzE=; b=liIeK+xPUei0lEBxStOyanHUYE TaRXiwE03YnksJRiqDK9vKDV0SuL4zjUX6vtvXUyKf2Clftum0N/fnxl/Oe8pOV+Akw9rlRSWvkqV aGExKqG9sfG4gtPUI3AQwCBME9IiGpDRKV8OXZnOGLK4Wv1FogJk5gIf6KvRKBv+y68w2c7duGRuW RDCyJ9OSOUrTIiuD/Ene81oeB8JyQkj3/5ZhOzfm+H+i41NDb8yMqO0uByUhv0zLzfniM4aXrblwG WkBlTS/mukROY3vYG1mu8DnONxaPTdKme6tU17Sr5ceVtJaJRdhp5oeUzyznkpu3l8215voWO/ArI n2K8GzGA==; Received: from clnet-p19-102.ikbnet.co.at ([83.175.77.102] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gPpZt-0007eI-0G; Thu, 22 Nov 2018 14:03:33 +0000 From: Christoph Hellwig To: iommu@lists.linux-foundation.org Cc: Linus Torvalds , Jon Mason , Joerg Roedel , David Woodhouse , Marek Szyprowski , Robin Murphy , x86@kernel.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-parisc@vger.kernel.org, xen-devel@lists.xenproject.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 03/24] dma-mapping: provide a generic DMA_MAPPING_ERROR Date: Thu, 22 Nov 2018 15:02:59 +0100 Message-Id: <20181122140320.24080-4-hch@lst.de> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181122140320.24080-1-hch@lst.de> References: <20181122140320.24080-1-hch@lst.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.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 15bd41447025..c323c539b7cb 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