From patchwork Fri Jun 14 14:44:25 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 10995723 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C26A414BB for ; Fri, 14 Jun 2019 14:45:19 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B147127BA5 for ; Fri, 14 Jun 2019 14:45:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A4F6928517; Fri, 14 Jun 2019 14:45:19 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 57CC6283CA for ; Fri, 14 Jun 2019 14:45:19 +0000 (UTC) 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=8SUySQPRC4+VFaxVVVYFe4mVr21st5bzr9/RkDP+Mzo=; b=GgDWlnP2XOw3uZ NpD5ig2Hp3+6b1+XhwiP47eT9Weh7VQPEz3C9+6u/3JGemY/sdtD97dRTZuKbf8Adc61yAr8HXIAu /iFMUWfa5wwk/Yrebbw/PrT1HXEz+2RkBTZHpSLKK5WtaPk24vsBnsBbxHFRegNuFMo1Hvb6Ec7hv yeAjM6J5MziUv6YqNDiU6In2QQUJ8s4CDC3jd1XrLgBG2py96BZElWU8kPH6l/RtWZ6YtPZ2yrRUu o4/xmdY+OWHMiJkqKPGyxRynDwMXfYZzLQuLutnIhdqmcrmLLePnJL44Vuy3Q2X1gOrmEsDtPZPth obdt1Lvb5/3GlaoAPiqQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hbnS3-00067p-V2; Fri, 14 Jun 2019 14:45:12 +0000 Received: from 213-225-9-13.nat.highway.a1.net ([213.225.9.13] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1hbnRY-0005pM-87; Fri, 14 Jun 2019 14:44:40 +0000 From: Christoph Hellwig To: Vineet Gupta Subject: [PATCH 1/7] arm-nommu: remove the partial DMA_ATTR_NON_CONSISTENT support Date: Fri, 14 Jun 2019 16:44:25 +0200 Message-Id: <20190614144431.21760-2-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190614144431.21760-1-hch@lst.de> References: <20190614144431.21760-1-hch@lst.de> MIME-Version: 1.0 X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jonas Bonn , linux-xtensa@linux-xtensa.org, Vladimir Murzin , linux-parisc@vger.kernel.org, Helge Deller , linux-kernel@vger.kernel.org, Stefan Kristiansson , iommu@lists.linux-foundation.org, openrisc@lists.librecores.org, Stafford Horne , linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP The arm-nommu DMA code supports DMA_ATTR_NON_CONSISTENT allocations, but does not provide a cache_sync operation. This means any user of it will never be able to actually transfer cache ownership and thus cause coherency bugs. Signed-off-by: Christoph Hellwig Reviewed-by: Vladimir Murzin --- arch/arm/mm/dma-mapping-nommu.c | 24 +++--------------------- 1 file changed, 3 insertions(+), 21 deletions(-) diff --git a/arch/arm/mm/dma-mapping-nommu.c b/arch/arm/mm/dma-mapping-nommu.c index f304b10e23a4..bc003df45546 100644 --- a/arch/arm/mm/dma-mapping-nommu.c +++ b/arch/arm/mm/dma-mapping-nommu.c @@ -39,18 +39,7 @@ static void *arm_nommu_dma_alloc(struct device *dev, size_t size, unsigned long attrs) { - void *ret; - - /* - * Try generic allocator first if we are advertised that - * consistency is not required. - */ - - if (attrs & DMA_ATTR_NON_CONSISTENT) - return dma_direct_alloc_pages(dev, size, dma_handle, gfp, - attrs); - - ret = dma_alloc_from_global_coherent(size, dma_handle); + void *ret = dma_alloc_from_global_coherent(size, dma_handle); /* * dma_alloc_from_global_coherent() may fail because: @@ -70,16 +59,9 @@ static void arm_nommu_dma_free(struct device *dev, size_t size, void *cpu_addr, dma_addr_t dma_addr, unsigned long attrs) { - if (attrs & DMA_ATTR_NON_CONSISTENT) { - dma_direct_free_pages(dev, size, cpu_addr, dma_addr, attrs); - } else { - int ret = dma_release_from_global_coherent(get_order(size), - cpu_addr); - - WARN_ON_ONCE(ret == 0); - } + int ret = dma_release_from_global_coherent(get_order(size), cpu_addr); - return; + WARN_ON_ONCE(ret == 0); } static int arm_nommu_dma_mmap(struct device *dev, struct vm_area_struct *vma,