From patchwork Sat May 27 13:47:43 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sricharan Ramabadhran X-Patchwork-Id: 9751869 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 16D2A60249 for ; Sat, 27 May 2017 13:49:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0EEDA28047 for ; Sat, 27 May 2017 13:49:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 02140283C5; Sat, 27 May 2017 13:48:59 +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=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E71A928380 for ; Sat, 27 May 2017 13:48:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757170AbdE0Nss (ORCPT ); Sat, 27 May 2017 09:48:48 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:39488 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757151AbdE0Nsp (ORCPT ); Sat, 27 May 2017 09:48:45 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id E3CF96146C; Sat, 27 May 2017 13:48:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1495892918; bh=87iUYTSCnhZhdj1K3OP+fmLijfj6xpl3g+Q5Qo3OvSs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FcuIeKMu4vpBI9BZ+B7jOJAHPtQGU8a5d7F95d1XQoNjdyX/tM7D2RBr0wHeLkml0 QAZfNh0Ao2dCkpjGndGAxFRDfsFDA97ytasRonFNHlfZzb6tpJU0NoTeBblNDEncQ+ xPITrjNbrytHXjxToWkSLIOIfzb6M93WBgi7lJLA= Received: from srichara-linux.qualcomm.com (blr-c-bdr-fw-01_globalnat_allzones-outside.qualcomm.com [103.229.19.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: sricharan@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id AA67A614DB; Sat, 27 May 2017 13:48:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1495892917; bh=87iUYTSCnhZhdj1K3OP+fmLijfj6xpl3g+Q5Qo3OvSs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oAX08q91Q3LBKCKboTysiSsMK2GqH56pXOauvxi4/p2Im4fvIQy6pnCQLiEmoPvUo CbDYXMLdXdSLVw/kH4NDOLJMqaxQqLQqus6jrjaBNq0VZDR+51bNJQMgo2KWB69Lwa qHgYxuLk7Tb5jAYw5d5pOOdVp8zaqLWdU501bnFI= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org AA67A614DB Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=sricharan@codeaurora.org From: Sricharan R To: robin.murphy@arm.com, will.deacon@arm.com, joro@8bytes.org, lorenzo.pieralisi@arm.com, iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, m.szyprowski@samsung.com, bhelgaas@google.com, linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, tn@semihalf.com, hanjun.guo@linaro.org, okaya@codeaurora.org, robh+dt@kernel.org, frowand.list@gmail.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, sudeep.holla@arm.com, rjw@rjwysocki.net, lenb@kernel.org, catalin.marinas@arm.com, arnd@arndb.de, linux-arch@vger.kernel.org, laurent.pinchart@ideasonboard.com, j.neuschaefer@gmx.net, geert@linux-m68k.org, magnus.damm@gmail.com, nwatters@codeaurora.org, linux@armlinux.org.uk Cc: sricharan@codeaurora.org Subject: [PATCH v6 4/6] ARM: dma-mapping: Don't tear down third-party mappings Date: Sat, 27 May 2017 19:17:43 +0530 Message-Id: <1495892865-9506-4-git-send-email-sricharan@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1495892865-9506-1-git-send-email-sricharan@codeaurora.org> References: <1495892865-9506-1-git-send-email-sricharan@codeaurora.org> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Laurent Pinchart arch_setup_dma_ops() is used in device probe code paths to create an IOMMU mapping and attach it to the device. The function assumes that the device is attached to a device-specific IOMMU instance (or at least a device-specific TLB in a shared IOMMU instance) and thus creates a separate mapping for every device. On several systems (Renesas R-Car Gen2 being one of them), that assumption is not true, and IOMMU mappings must be shared between multiple devices. In those cases the IOMMU driver knows better than the generic ARM dma-mapping layer and attaches mapping to devices manually with arm_iommu_attach_device(), which sets the DMA ops for the device. The arch_setup_dma_ops() function takes this into account and bails out immediately if the device already has DMA ops assigned. However, the corresponding arch_teardown_dma_ops() function, called from driver unbind code paths (including probe deferral), will tear the mapping down regardless of who created it. When the device is reprobed arch_setup_dma_ops() will be called again but won't perform any operation as the DMA ops will still be set. We need to reset the DMA ops in arch_teardown_dma_ops() to fix this. However, we can't do so unconditionally, as then a new mapping would be created by arch_setup_dma_ops() when the device is reprobed, regardless of whether the device needs to share a mapping or not. We must thus keep track of whether arch_setup_dma_ops() created the mapping, and only in that case tear it down in arch_teardown_dma_ops(). Keep track of that information in the dev_archdata structure. As the structure is embedded in all instances of struct device let's not grow it, but turn the existing dma_coherent bool field into a bitfield that can be used for other purposes. Fixes: 09515ef5ddad ("of/acpi: Configure dma operations at probe time for platform/amba/pci bus devices") Reviewed-by: Robin Murphy Signed-off-by: Laurent Pinchart --- arch/arm/include/asm/device.h | 3 ++- arch/arm/mm/dma-mapping.c | 4 ++++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/arm/include/asm/device.h b/arch/arm/include/asm/device.h index 36ec9c8..3234fe9 100644 --- a/arch/arm/include/asm/device.h +++ b/arch/arm/include/asm/device.h @@ -19,7 +19,8 @@ struct dev_archdata { #ifdef CONFIG_XEN const struct dma_map_ops *dev_dma_ops; #endif - bool dma_coherent; + unsigned int dma_coherent:1; + unsigned int dma_ops_setup:1; }; struct omap_device; diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index c742dfd..b48998f 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -2430,9 +2430,13 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, dev->dma_ops = xen_dma_ops; } #endif + dev->archdata.dma_ops_setup = true; } void arch_teardown_dma_ops(struct device *dev) { + if (!dev->archdata.dma_ops_setup) + return; + arm_teardown_iommu_dma_ops(dev); }