From patchwork Mon Jan 23 16:18:04 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sricharan Ramabadhran X-Patchwork-Id: 9532957 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 8CE486042D for ; Mon, 23 Jan 2017 16:18:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7CA982846B for ; Mon, 23 Jan 2017 16:18:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 714AA2846F; Mon, 23 Jan 2017 16:18:38 +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=ham 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 14F542846B for ; Mon, 23 Jan 2017 16:18:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751175AbdAWQSh (ORCPT ); Mon, 23 Jan 2017 11:18:37 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:33518 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750742AbdAWQSg (ORCPT ); Mon, 23 Jan 2017 11:18:36 -0500 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 686F06035F; Mon, 23 Jan 2017 16:18:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1485188315; bh=W1fOZGe5vCQKh52TP9cYGmPCjUclEQbKaRkvNV2/xqI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YWjqfBZ87ULMJy8xYn4U0QKfCw9B/xtW86tiG9RpsbG9wJivh9Yg8h+YWUf7S/xtq BzNTIfoRhK0VocI80wBEGiQxOT8grRPOpRS2ieMgeaJWZhbRv2cGCjKoRZuYRtKPvs zW+/fEHgUpYV5sp6dnQv3/M5vOdam2pIhRMWRr+c= 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 C869C607E1; Mon, 23 Jan 2017 16:18:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1485188314; bh=W1fOZGe5vCQKh52TP9cYGmPCjUclEQbKaRkvNV2/xqI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jwOCtXVE1G823LogfqOFOCbuydpfcW+l8RNsCLJa0m2UiGQ9hi6xbN2VV1n9uFg7D tTLpi6bu9STDgB69Pbi/fr5zZsyCKm/fYlHpEZYqHsUqgkb+9fGbeNLpUsdpUE2QA2 HUgqz9orjQJXJb8dTrBE1Pc2ZvyXrN9OqmLO0heY= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org C869C607E1 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 Cc: sricharan@codeaurora.org Subject: [PATCH V7 02/11] iommu/of: Prepare for deferred IOMMU configuration Date: Mon, 23 Jan 2017 21:48:04 +0530 Message-Id: <1485188293-20263-3-git-send-email-sricharan@codeaurora.org> X-Mailer: git-send-email 1.8.2.1 In-Reply-To: <1485188293-20263-1-git-send-email-sricharan@codeaurora.org> References: <1485188293-20263-1-git-send-email-sricharan@codeaurora.org> Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.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; }