From patchwork Mon Apr 25 15:58:06 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sricharan Ramabadhran X-Patchwork-Id: 8930261 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id D639E9F1C1 for ; Mon, 25 Apr 2016 16:00:24 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 12A58201F2 for ; Mon, 25 Apr 2016 16:00:24 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 210D9201EC for ; Mon, 25 Apr 2016 16:00:22 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1auiuQ-0005EL-EA; Mon, 25 Apr 2016 15:58:50 +0000 Received: from smtp.codeaurora.org ([198.145.29.96]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1auiuM-00051N-64 for linux-arm-kernel@lists.infradead.org; Mon, 25 Apr 2016 15:58:47 +0000 Received: from smtp.codeaurora.org (localhost [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id 038D9612EB; Mon, 25 Apr 2016 15:58:29 +0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1000) id C0E2F6120A; Mon, 25 Apr 2016 15:58:28 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from blr-ubuntu-32.ap.qualcomm.com (unknown [202.46.23.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: sricharan@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 7EDF7612EB; Mon, 25 Apr 2016 15:58:24 +0000 (UTC) From: Sricharan R To: will.deacon@arm.com, robin.murphy@arm.com, joro@8bytes.org, iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, laurent.pinchart@ideasonboard.com Subject: [RFC 1/9] arm: dma-mapping: Don't override dma_ops in arch_setup_dma_ops() Date: Mon, 25 Apr 2016 21:28:06 +0530 Message-Id: <1461599894-1969-2-git-send-email-sricharan@codeaurora.org> X-Mailer: git-send-email 1.8.2.1 In-Reply-To: <1461599894-1969-1-git-send-email-sricharan@codeaurora.org> References: <1461599894-1969-1-git-send-email-sricharan@codeaurora.org> X-Virus-Scanned: ClamAV using ClamSMTP X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160425_085846_266697_365266E1 X-CRM114-Status: GOOD ( 13.72 ) X-Spam-Score: -2.9 (--) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: sricharan@codeaurora.org MIME-Version: 1.0 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 From: Laurent Pinchart The arch_setup_dma_ops() function is in charge of setting dma_ops with a call to set_dma_ops(). set_dma_ops() is also called from - highbank and mvebu bus notifiers - dmabounce (to be replaced with swiotlb) - arm_iommu_attach_device (arm_iommu_attach_device is itself called from IOMMU and bus master device drivers) To allow the arch_setup_dma_ops() call to be moved from device add time to device probe time we must ensure that dma_ops already setup by any of the above callers will not be overriden. Aftering replacing dmabounce with swiotlb, converting IOMMU drivers to of_xlate and taking care of highbank and mvebu, the workaround should be removed. Signed-off-by: Laurent Pinchart --- arch/arm/mm/dma-mapping.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 0eca381..ccf60a2 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -2126,6 +2126,15 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, struct dma_map_ops *dma_ops; dev->archdata.dma_coherent = coherent; + + /* + * Don't override the dma_ops if they have already been set. Ideally + * this should be the only location where dma_ops are set, remove this + * check when all other callers of set_dma_ops will have disappeared. + */ + if (dev->archdata.dma_ops) + return; + if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu)) dma_ops = arm_get_iommu_dma_map_ops(coherent); else