From patchwork Thu Mar 9 19:00:52 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sricharan Ramabadhran X-Patchwork-Id: 9614039 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 145C860417 for ; Thu, 9 Mar 2017 19:02:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0FD4F223A6 for ; Thu, 9 Mar 2017 19:02:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 00E2B2866F; Thu, 9 Mar 2017 19:02:44 +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=-1.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 5F2F1223A6 for ; Thu, 9 Mar 2017 19:02:44 +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:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: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=HrcMbRiUkfG6owjB07vXuIWcplQRcU/2CZlQRxjd1nE=; b=nmRNErjePT2FEpffgHPcEUma1Z cC+3nItRn5dIVpI3xlUeybbtCOw02FB3sN/VeNpVxYS+ze87T/jkwX0bUhwr3gAGWj2aUm6FS/007 BJSrmdDf82LeXlDvbXz0hwRSvNCiITCCiKf4MQF2ZjoVOQ1dD/E33yniiyMEOR8JSh1tTE/0fEoeW 9Jd7v6erF3j2JDGXNUU2iupOWO5r7jzomCYKbXFcfQXsz63tq6kHWvS4zMZOeNqXsJLRaoifQWkWb nm3jfXEmCRwWWj/LmOOAO1xJc/ADnXYhgRPJWRu/maXCdg9IZpsxLSM7EuE/OzPEHjRrHCp9V9hcQ aNHoZz8w==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1cm3Kl-0008Iy-PG; Thu, 09 Mar 2017 19:02:43 +0000 Received: from smtp.codeaurora.org ([198.145.29.96]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1cm3Jo-0007eg-MM for linux-arm-kernel@lists.infradead.org; Thu, 09 Mar 2017 19:01:46 +0000 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 94F1860910; Thu, 9 Mar 2017 19:01:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1489086085; bh=N+f/OtpVUSo8nLiC3mY8mhDsIhMTt2j7bE+9yfSIY1E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KHHucO9FyRQ+MG/gUiPaecfMhJj1ZYCzELVvreMkQTu9Qnh5jgvqhqQBPjkRW/QXy uREFCc74SK+9py3Vd/FD/r0wOdlNtwGvsjmmU1sgaMWfTpoP1FrquPR8vrlbKqBG4U 5gIuaVzrwjVfHllJYA0wIFSDoR1O/ZUTN4sovroI= 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 D374E6080C; Thu, 9 Mar 2017 19:01:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1489086084; bh=N+f/OtpVUSo8nLiC3mY8mhDsIhMTt2j7bE+9yfSIY1E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=i4dx5uFrjVq2fKqFWeyCcPBmFHE7uA/U/D5oit0U3AGq00c+ihKkXzC+i59pkL2Ka pj74L4vzaO8UD03qTjZDcU3FwD/uPicLTtVoq3hUcc31Ld2ZKLmw+bNKBKtf0NnJ/A zc5AKCdF3l5vyautsFZ3S/5JMUvB/jdxSZ877Nbg= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org D374E6080C 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 Subject: [PATCH V9 02/11] iommu/of: Prepare for deferred IOMMU configuration Date: Fri, 10 Mar 2017 00:30:52 +0530 Message-Id: <1489086061-9356-3-git-send-email-sricharan@codeaurora.org> X-Mailer: git-send-email 1.8.2.1 In-Reply-To: <1489086061-9356-1-git-send-email-sricharan@codeaurora.org> References: <1489086061-9356-1-git-send-email-sricharan@codeaurora.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170309_110144_793057_14ED3269 X-CRM114-Status: GOOD ( 18.58 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 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). Tested-by: Marek Szyprowski Signed-off-by: Robin Murphy --- drivers/iommu/of_iommu.c | 43 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 42 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index 8f4e599..c8be889 100644 --- a/drivers/iommu/of_iommu.c +++ b/drivers/iommu/of_iommu.c @@ -96,6 +96,19 @@ int of_get_dma_window(struct device_node *dn, const char *prefix, int index, } EXPORT_SYMBOL_GPL(of_get_dma_window); +static bool of_iommu_driver_present(struct device_node *np) +{ + /* + * If the IOMMU still isn't ready by the time we reach init, assume + * it never will be. We don't want to defer indefinitely, nor attempt + * to dereference __iommu_of_table after it's been freed. + */ + if (system_state > SYSTEM_BOOTING) + return false; + + return of_match_node(&__iommu_of_table, np); +} + static const struct iommu_ops *of_iommu_xlate(struct device *dev, struct of_phandle_args *iommu_spec) { @@ -104,12 +117,20 @@ int of_get_dma_window(struct device_node *dn, const char *prefix, int index, int err; ops = iommu_ops_from_fwnode(fwnode); - if (!ops || !ops->of_xlate) + if ((ops && !ops->of_xlate) || + (!ops && !of_iommu_driver_present(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 +207,34 @@ 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; }