From patchwork Wed Nov 30 00:22:16 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sricharan Ramabadhran X-Patchwork-Id: 9453295 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 476416071E for ; Wed, 30 Nov 2016 00:26:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 38F79287AD for ; Wed, 30 Nov 2016 00:26:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2C01728486; Wed, 30 Nov 2016 00:26:03 +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=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED, T_DKIM_INVALID autolearn=unavailable version=3.3.1 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.wl.linuxfoundation.org (Postfix) with ESMTPS id 5CFBA28486 for ; Wed, 30 Nov 2016 00:26:01 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1cBshH-0001HP-Ip; Wed, 30 Nov 2016 00:24:27 +0000 Received: from smtp.codeaurora.org ([198.145.29.96]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1cBsgM-0000iD-Im for linux-arm-kernel@lists.infradead.org; Wed, 30 Nov 2016 00:23:31 +0000 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 797106155C; Wed, 30 Nov 2016 00:23:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1480465393; bh=W1fOZGe5vCQKh52TP9cYGmPCjUclEQbKaRkvNV2/xqI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kP8eHrfVPsd81XSIn5DwRftxjQy1P4PqRVOJcZhW9QMvC96rKgiE5MyPF9j8sOeyE rvB4pxop47slDh+xvtf1fMrogkDtGzZjul/9E8a5CuiY1jXEx5SKnRzmzy0g436CaZ /m5CnJQyvaz5t2C+yIWh2q2QHpbHTuE8ui9O1r9Y= 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 EE9C0614F9; Wed, 30 Nov 2016 00:23:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1480465390; bh=W1fOZGe5vCQKh52TP9cYGmPCjUclEQbKaRkvNV2/xqI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IpMRpzj+q3+9f3+aFQ0DJbtT5BAapfdsZSt16C62LvJIYJe6w5W0pxwKMSvwd6maj O7a2G+2bMXsnaakoctYkpBMVIOJzMy/m9N3rIAFNa3lTCA277giQRTLdOjGWvzE8Zi u8l1y2f9+KrgABpVHxtUm/7YbcV9vfHM+NsmvMX4= DMARC-Filter: OpenDMARC Filter v1.3.1 smtp.codeaurora.org EE9C0614F9 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=pass 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 Subject: [PATCH 02/10] iommu/of: Prepare for deferred IOMMU configuration Date: Wed, 30 Nov 2016 05:52:16 +0530 Message-Id: <1480465344-11862-3-git-send-email-sricharan@codeaurora.org> X-Mailer: git-send-email 1.8.2.1 In-Reply-To: <1480465344-11862-1-git-send-email-sricharan@codeaurora.org> References: <1480465344-11862-1-git-send-email-sricharan@codeaurora.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20161129_162330_746178_9DE6AC9D X-CRM114-Status: GOOD ( 16.67 ) 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: Robin Murphy IOMMU configuration represents unchanging properties of the hardware, and as such should only need happen once in a device's lifetime, but the necessary interaction with the IOMMU device and driver complicates exactly when that point should be. Since the only reasonable tool available for handling the inter-device dependency is probe deferral, we need to prepare of_iommu_configure() to run later than it is currently called (i.e. at driver probe rather than device creation), to handle being retried, and to tell whether a not-yet present IOMMU should be waited for or skipped (by virtue of having declared a built-in driver or not). Signed-off-by: Robin Murphy --- drivers/iommu/of_iommu.c | 30 +++++++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index ee49081..349bd1d 100644 --- a/drivers/iommu/of_iommu.c +++ b/drivers/iommu/of_iommu.c @@ -104,12 +104,20 @@ int of_get_dma_window(struct device_node *dn, const char *prefix, int index, int err; ops = iommu_get_instance(fwnode); - if (!ops || !ops->of_xlate) + if ((ops && !ops->of_xlate) || + (!ops && !of_match_node(&__iommu_of_table, iommu_spec->np))) return NULL; err = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops); if (err) return ERR_PTR(err); + /* + * The otherwise-empty fwspec handily serves to indicate the specific + * IOMMU device we're waiting for, which will be useful if we ever get + * a proper probe-ordering dependency mechanism in future. + */ + if (!ops) + return ERR_PTR(-EPROBE_DEFER); err = ops->of_xlate(dev, iommu_spec); if (err) @@ -186,14 +194,34 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, struct device_node *master_np) { const struct iommu_ops *ops; + struct iommu_fwspec *fwspec = dev->iommu_fwspec; if (!master_np) return NULL; + if (fwspec) { + if (fwspec->ops) + return fwspec->ops; + + /* In the deferred case, start again from scratch */ + iommu_fwspec_free(dev); + } + if (dev_is_pci(dev)) ops = of_pci_iommu_init(to_pci_dev(dev), master_np); else ops = of_platform_iommu_init(dev, master_np); + /* + * If we have reason to believe the IOMMU driver missed the initial + * add_device callback for dev, replay it to get things in order. + */ + if (!IS_ERR_OR_NULL(ops) && ops->add_device && + dev->bus && !dev->iommu_group) { + int err = ops->add_device(dev); + + if (err) + ops = ERR_PTR(err); + } return IS_ERR(ops) ? NULL : ops; }