From patchwork Mon Sep 5 17:08:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thierry Reding X-Patchwork-Id: 602817 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AF71FECAAD3 for ; Mon, 5 Sep 2022 17:09:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238083AbiIERJF (ORCPT ); Mon, 5 Sep 2022 13:09:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32780 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237958AbiIERIp (ORCPT ); Mon, 5 Sep 2022 13:08:45 -0400 Received: from mail-ej1-x62d.google.com (mail-ej1-x62d.google.com [IPv6:2a00:1450:4864:20::62d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 60B455E652; Mon, 5 Sep 2022 10:08:44 -0700 (PDT) Received: by mail-ej1-x62d.google.com with SMTP id qh18so18239251ejb.7; Mon, 05 Sep 2022 10:08:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date; bh=arsiduc6sJIa+xojp1J20696vz1D9BKvyFnTAqu9ZoI=; b=XcxSEsrCTHZKvIUfXephYIltJhgoR72sbedd/IYzTfnHMlGr1Xo9Vd5rSnGv+EYg4J r8j1Fglz3X9C2z/Beb6NQLThE17I8luHMGI63KufiKgXMXN8BAb3GRgVk6xgUuISBIWi 9AhFUL3rH+V2EQoXh+0SDO62Pxsmz1D8gWBzHj5JoRnsU1LCOWFln2iqXLhdeI9U88fq ytXa3m6XbtIWphBY5wJYTM1y6hLrXSadIczc85sDxAB7jwUjlVu3Pwvb0Mvs6PtsA2Yq pz1xBaAJ2f/LcJ+Gx88nc2cxbEnUvBFvPZU3RJck4fuwcs1o8xTi152raDTwmQLBu54f MzZw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date; bh=arsiduc6sJIa+xojp1J20696vz1D9BKvyFnTAqu9ZoI=; b=MnJYDaKkG+5CKiiQVrQzGqQKjfMaWK/KWTvHZF+uoucKVoi47F3IWqYIp6pDGy8VWZ 95LXuLZLYfarjL/JcAIV9zjziQqzZtX+ExbAxx3leV+FkM8urQBdKRv3n8QbUQmBOcij 36CYUJ3Y7SgCz+BG4zy9NsTevo723m4TAsz+RNhgMH+lJknZ2PsJSoCP7+woSFwmEL0l IIZ6c59OuNgVBA3znaSlB5rnmMYdjLovv6i4Vil4cQHDJUBF6rgtm6jsQxU0/9itZHJ5 Ij/oOpp+VMUeqCwEs6q0zEVYDOh1maBozgCjlTa1AQUX2HSnlx7k8XvEz7d+QGBMwncr EwCA== X-Gm-Message-State: ACgBeo1NoSNv3DAErrYJt+LJSbDHwZ0qRH2m2vY1YtY1hyHeilGiIU9P 67Vtu1lCDXtj4toQqNsixO0= X-Google-Smtp-Source: AA6agR64ubHA8j4JRCQD1nSnG5ANK8jJxR/k7iS4+Vs1ek+wg4Nj++2r77WdJ2IonpZWv+bVOw8uSA== X-Received: by 2002:a17:907:9710:b0:731:67b1:dc3b with SMTP id jg16-20020a170907971000b0073167b1dc3bmr37321083ejc.709.1662397722823; Mon, 05 Sep 2022 10:08:42 -0700 (PDT) Received: from localhost (p200300e41f12c800f22f74fffe1f3a53.dip0.t-ipconnect.de. [2003:e4:1f12:c800:f22f:74ff:fe1f:3a53]) by smtp.gmail.com with ESMTPSA id d21-20020a170906305500b0073d6ab5bcaasm5255997ejd.212.2022.09.05.10.08.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 05 Sep 2022 10:08:41 -0700 (PDT) From: Thierry Reding To: Rob Herring , Joerg Roedel Cc: Will Deacon , Robin Murphy , Nicolin Chen , Krishna Reddy , Dmitry Osipenko , Alyssa Rosenzweig , Janne Grunau , Sameer Pujar , devicetree@vger.kernel.org, iommu@lists.linux-foundation.org, linux-tegra@vger.kernel.org, asahi@lists.linux.dev, Frank Rowand , Rob Herring Subject: [PATCH v8 2/5] iommu: Implement of_iommu_get_resv_regions() Date: Mon, 5 Sep 2022 19:08:30 +0200 Message-Id: <20220905170833.396892-3-thierry.reding@gmail.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220905170833.396892-1-thierry.reding@gmail.com> References: <20220905170833.396892-1-thierry.reding@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org From: Thierry Reding This is an implementation that IOMMU drivers can use to obtain reserved memory regions from a device tree node. It uses the reserved-memory DT bindings to find the regions associated with a given device. If these regions are marked accordingly, identity mappings will be created for them in the IOMMU domain that the devices will be attached to. Cc: Frank Rowand Cc: devicetree@vger.kernel.org Reviewed-by: Rob Herring Signed-off-by: Thierry Reding --- Changes in v8: - cleanup set-but-unused variables Changes in v6: - remove reference to now unused dt-bindings/reserved-memory.h include Changes in v5: - update for new "iommu-addresses" device tree bindings Changes in v4: - fix build failure on !CONFIG_OF_ADDRESS Changes in v3: - change "active" property to identity mapping flag that is part of the memory region specifier (as defined by #memory-region-cells) to allow per-reference flags to be used Changes in v2: - use "active" property to determine whether direct mappings are needed drivers/iommu/of_iommu.c | 85 ++++++++++++++++++++++++++++++++++++++++ include/linux/of_iommu.h | 8 ++++ 2 files changed, 93 insertions(+) diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index 5696314ae69e..6617096ad15f 100644 --- a/drivers/iommu/of_iommu.c +++ b/drivers/iommu/of_iommu.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include #include @@ -172,3 +173,87 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, return ops; } + +/** + * of_iommu_get_resv_regions - reserved region driver helper for device tree + * @dev: device for which to get reserved regions + * @list: reserved region list + * + * IOMMU drivers can use this to implement their .get_resv_regions() callback + * for memory regions attached to a device tree node. See the reserved-memory + * device tree bindings on how to use these: + * + * Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt + */ +void of_iommu_get_resv_regions(struct device *dev, struct list_head *list) +{ +#if IS_ENABLED(CONFIG_OF_ADDRESS) + struct of_phandle_iterator it; + int err; + + of_for_each_phandle(&it, err, dev->of_node, "memory-region", NULL, 0) { + struct iommu_resv_region *region; + struct resource res; + const __be32 *maps; + int size; + + memset(&res, 0, sizeof(res)); + + /* + * The "reg" property is optional and can be omitted by reserved-memory regions + * that represent reservations in the IOVA space, which are regions that should + * not be mapped. + */ + if (of_find_property(it.node, "reg", NULL)) { + err = of_address_to_resource(it.node, 0, &res); + if (err < 0) { + dev_err(dev, "failed to parse memory region %pOF: %d\n", + it.node, err); + continue; + } + } + + maps = of_get_property(it.node, "iommu-addresses", &size); + if (maps) { + const __be32 *end = maps + size / sizeof(__be32); + struct device_node *np; + u32 phandle; + int na, ns; + + while (maps < end) { + phys_addr_t start; + size_t length; + + phandle = be32_to_cpup(maps++); + np = of_find_node_by_phandle(phandle); + na = of_n_addr_cells(np); + ns = of_n_size_cells(np); + + start = of_translate_dma_address(np, maps); + length = of_read_number(maps + na, ns); + + if (np == dev->of_node) { + int prot = IOMMU_READ | IOMMU_WRITE; + enum iommu_resv_type type; + + /* + * IOMMU regions without an associated physical region + * cannot be mapped and are simply reservations. + */ + if (res.end > res.start) + type = IOMMU_RESV_DIRECT_RELAXABLE; + else + type = IOMMU_RESV_RESERVED; + + region = iommu_alloc_resv_region(start, length, prot, type); + if (region) + list_add_tail(®ion->list, list); + } + + maps += na + ns; + } + } + } +#endif +} +EXPORT_SYMBOL(of_iommu_get_resv_regions); diff --git a/include/linux/of_iommu.h b/include/linux/of_iommu.h index 55c1eb300a86..9a5e6b410dd2 100644 --- a/include/linux/of_iommu.h +++ b/include/linux/of_iommu.h @@ -12,6 +12,9 @@ extern const struct iommu_ops *of_iommu_configure(struct device *dev, struct device_node *master_np, const u32 *id); +extern void of_iommu_get_resv_regions(struct device *dev, + struct list_head *list); + #else static inline const struct iommu_ops *of_iommu_configure(struct device *dev, @@ -21,6 +24,11 @@ static inline const struct iommu_ops *of_iommu_configure(struct device *dev, return NULL; } +static inline void of_iommu_get_resv_regions(struct device *dev, + struct list_head *list) +{ +} + #endif /* CONFIG_OF_IOMMU */ #endif /* __OF_IOMMU_H */