From patchwork Fri Nov 11 16:18:05 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thierry Reding X-Patchwork-Id: 624013 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 B41F9C4332F for ; Fri, 11 Nov 2022 16:18:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232841AbiKKQSW (ORCPT ); Fri, 11 Nov 2022 11:18:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234002AbiKKQSV (ORCPT ); Fri, 11 Nov 2022 11:18:21 -0500 Received: from mail-wr1-x431.google.com (mail-wr1-x431.google.com [IPv6:2a00:1450:4864:20::431]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 93A0E68AD8; Fri, 11 Nov 2022 08:18:19 -0800 (PST) Received: by mail-wr1-x431.google.com with SMTP id d9so2391467wrm.13; Fri, 11 Nov 2022 08:18:19 -0800 (PST) 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 :message-id:reply-to; bh=UFYlmsCB+de1MKykLCFPxeRpHC1cNZyXUBWiz3WJZhE=; b=m0MVD/CdFH+Jhub9b9cVXL6+v2ZVLU8Qv8Aa0UDEUvxL1PsQuSFDx9p5QdfS1QYZmQ XIxtxjPdPpdNGg2NqbZXqV2hgkAYTuW3Gqi9KtBO1x4NyyCnY0Q7NlZkwnaWaq9MUbvo aQOLokkP++DqOwCb9Wn+lb9FiE3BCXTGQM0Pd3tMN888p2rTj5YsO9gzwNwlwtfEoS6P M2EToW5HmtBHpu6Amc2lQt/6Gn9YOtwRthyyejgWm1aBMNOyc6QqpWRmr4KlTkEesp+P RpxXrb1yVYaFBmq4FvauFBK8AHdQGOZ09LpCwBT1/znXjEkSSOCbFC9AFyL9UJ2gmjeo LMOA== 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:message-id:reply-to; bh=UFYlmsCB+de1MKykLCFPxeRpHC1cNZyXUBWiz3WJZhE=; b=nNLJNrBGe5D6fd2yc00f+uq2E29wV2zrLsV/r6TNYRkmFCxohsrkbMSYNmQ1rCBrMU Zb2O0E5Y50yW65mj4r7dmiNfqQn+XE67kICkuELkcl00XueEyylF0aEcweINTj4Vq08q Y2tnR/kORjnj3tcaKaelhaQDTRRHOxyeZSdsrBadX2IDofbT5FCX+dYn6AN8TNE5fKee HhbbsYsL5MqV44BmFwbtMXDDMCdm9PVrgrfndFX6AYtMvs33wOYvWcHGqnQULgJk4Jjs Rtkw1yReT0oUrZ9Q9hNG/ZPbMJaN1jdt+rjWDjtzi/zApO4g6X8zjlvRKnZ+kg9bvfr1 qptQ== X-Gm-Message-State: ANoB5pn0FpuRUl4UYTQaFsN5sD7Bby25jx6zVmy6/sq9hgyPVJELx2QE xgWk5x3/GT368z09az818+A= X-Google-Smtp-Source: AA0mqf53WVJ+L6bov99XmumvVtupfxkS3Af7POoygSof3WxWKR0KRGYMzenSg9pN/4P7jCtGKnHnaA== X-Received: by 2002:a5d:528c:0:b0:22f:da60:345 with SMTP id c12-20020a5d528c000000b0022fda600345mr1721302wrv.218.1668183497900; Fri, 11 Nov 2022 08:18:17 -0800 (PST) Received: from localhost (p200300e41f201d00f22f74fffe1f3a53.dip0.t-ipconnect.de. [2003:e4:1f20:1d00:f22f:74ff:fe1f:3a53]) by smtp.gmail.com with ESMTPSA id z8-20020adfec88000000b00236722ebe66sm2297016wrn.75.2022.11.11.08.18.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 11 Nov 2022 08:18:16 -0800 (PST) From: Thierry Reding To: Rob Herring , Joerg Roedel Cc: Will Deacon , Robin Murphy , Nicolin Chen , Krishna Reddy , Ashish Mhetre , Dmitry Osipenko , Alyssa Rosenzweig , Janne Grunau , Sameer Pujar , Lucas Stach , devicetree@vger.kernel.org, iommu@lists.linux-foundation.org, linux-tegra@vger.kernel.org, asahi@lists.linux.dev, Frank Rowand , Rob Herring Subject: [PATCH v11 4/5] iommu: Implement of_iommu_get_resv_regions() Date: Fri, 11 Nov 2022 17:18:05 +0100 Message-Id: <20221111161806.630527-5-thierry.reding@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221111161806.630527-1-thierry.reding@gmail.com> References: <20221111161806.630527-1-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 v10: - extract more code into the new iommu_resv_region_get_type() function - rename variables for physical and I/O virtual addresses for clarity - default to IOMMU_RESV_DIRECT instead of IOMMU_RESV_DIRECT_RELAXABLE - use newly introduced of_translate_dma_region() Changes in v9: - address review comments by Robin Murphy: - warn about non-direct mappings since they are not supported yet - cleanup code to require less indentation - narrow scope of variables 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 | 94 ++++++++++++++++++++++++++++++++++++++++ include/linux/of_iommu.h | 8 ++++ 2 files changed, 102 insertions(+) diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index 5696314ae69e..fa7c63a4abbf 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 +173,96 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, return ops; } + +static enum iommu_resv_type iommu_resv_region_get_type(struct device *dev, struct resource *phys, + phys_addr_t start, size_t length) +{ + phys_addr_t end = start + length - 1; + + /* + * IOMMU regions without an associated physical region cannot be + * mapped and are simply reservations. + */ + if (phys->start >= phys->end) + return IOMMU_RESV_RESERVED; + + /* may be IOMMU_RESV_DIRECT_RELAXABLE for certain cases */ + if (start == phys->start && end == phys->end) + return IOMMU_RESV_DIRECT; + + dev_warn(dev, "treating non-direct mapping [%pr] -> [%pap-%pap] as reservation\n", &phys, + &start, &end); + return IOMMU_RESV_RESERVED; +} + +/** + * 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) { + const __be32 *maps, *end; + struct resource phys; + int size; + + memset(&phys, 0, sizeof(phys)); + + /* + * 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, &phys); + 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) + continue; + + end = maps + size / sizeof(__be32); + + while (maps < end) { + struct device_node *np; + u32 phandle; + + phandle = be32_to_cpup(maps++); + np = of_find_node_by_phandle(phandle); + + if (np == dev->of_node) { + int prot = IOMMU_READ | IOMMU_WRITE; + struct iommu_resv_region *region; + enum iommu_resv_type type; + phys_addr_t iova; + size_t length; + + maps = of_translate_dma_region(np, maps, &iova, &length); + type = iommu_resv_region_get_type(dev, &phys, iova, length); + + region = iommu_alloc_resv_region(iova, length, prot, type, + GFP_KERNEL); + if (region) + list_add_tail(®ion->list, list); + } + } + } +#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 */