From patchwork Fri Sep 23 12:35:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thierry Reding X-Patchwork-Id: 608978 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 A9DE8C6FA82 for ; Fri, 23 Sep 2022 12:36:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230463AbiIWMgN (ORCPT ); Fri, 23 Sep 2022 08:36:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49274 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230297AbiIWMgL (ORCPT ); Fri, 23 Sep 2022 08:36:11 -0400 Received: from mail-ej1-x633.google.com (mail-ej1-x633.google.com [IPv6:2a00:1450:4864:20::633]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6CA7712C69D; Fri, 23 Sep 2022 05:36:09 -0700 (PDT) Received: by mail-ej1-x633.google.com with SMTP id lh5so331287ejb.10; Fri, 23 Sep 2022 05:36:09 -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=VxAgfZrGtKMqyWww7/oY0OjO0zC4CiRj830AgLQKw6A=; b=IOUD+xaU5E/F7kEvra/WnLic+tO0zmZBLmOqO/FRB4+PmvPbeBf1Kz5yAKPKd8JTTZ CiBcERIhyNfqEjKmVNhpMiV/CTnZmtGNznjb0OL20Abgu9u9Xxp7TVabBIFHywSaG667 5QTjuPOiz+Vkj4/K6AuMAreCbCu1pDeFLOR5OaCG5sXSBszKHPtX/Jcy8+q5M2lC9OtS +Twrx5+bT0sfNiBoWo1KWPxpIxuE00vFoVjnS5/Sx1eFOW1yhqJQ+rzt5Ex0ke520TQt ILoXGYkZx1770NGapAzMNP7I9N0o+zGg83T5ipYj2AfIHEYkJWjcrbDNIrsy/ki9ghEN 3auQ== 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=VxAgfZrGtKMqyWww7/oY0OjO0zC4CiRj830AgLQKw6A=; b=WN+O3YNtOJTCweRQLvGW5izNHI5VVrXt3n6YBRUUGPTBXJrKak7/wiNG2qiaOHgvHA lCBkQSsscZKtG/MKpiaf/tPi59eVcWPvtpEZhLF1pnH6VkWIzSFDkCeUtCqy+vVj8W3V WDBjrPN4tnXjGS95GC2FkCsS2oYDCamayPjRaTutHGoFdORIotbIA+WmiAWnVmqDIQk1 RvKzII8A47ag8x4qjNgAmCd0GAw7YiT7yOZ+9ra87wD0NFUCf3f7YLSEsYBjGGlysQed OSvV5bwseqFpbU/azNAIIHyihKashAqhvySrYQVYpy1+f3Jf/4zDEgQ3A0eHRI7k4O1c N0Sg== X-Gm-Message-State: ACrzQf2MvqSYEoQSnN8Gj8P9vo2hOjEh3RNysxNSFg1Lc0z+g4fdm8cT 8gVeq3iMxME2MVeDCPdPLCqB+UG2pYo= X-Google-Smtp-Source: AMsMyM76XL9JeQ+lbbmH11hJ+XADkKHoxMNwem9w++iHWQt+eyROenbt9lR/BzzNNXTGywSAykatsg== X-Received: by 2002:a17:907:94d6:b0:782:b10a:7e91 with SMTP id dn22-20020a17090794d600b00782b10a7e91mr1772183ejc.220.1663936567432; Fri, 23 Sep 2022 05:36:07 -0700 (PDT) Received: from localhost (p200300e41f201d00f22f74fffe1f3a53.dip0.t-ipconnect.de. [2003:e4:1f20:1d00:f22f:74ff:fe1f:3a53]) by smtp.gmail.com with ESMTPSA id j18-20020aa7de92000000b0044657ecfbb5sm456417edv.13.2022.09.23.05.36.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 23 Sep 2022 05:36:06 -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 v9 2/5] iommu: Implement of_iommu_get_resv_regions() Date: Fri, 23 Sep 2022 14:35:54 +0200 Message-Id: <20220923123557.866972-3-thierry.reding@gmail.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220923123557.866972-1-thierry.reding@gmail.com> References: <20220923123557.866972-1-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 Signed-off-by: Thierry Reding --- 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 | 104 +++++++++++++++++++++++++++++++++++++++ include/linux/of_iommu.h | 8 +++ 2 files changed, 112 insertions(+) diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index 5696314ae69e..0bf2b08bca0a 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 +173,106 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, return ops; } + +static inline bool check_direct_mapping(struct device *dev, struct resource *phys, + phys_addr_t start, phys_addr_t end) +{ + if (start != phys->start || end != phys->end) { + dev_warn(dev, "treating non-direct mapping [%pr] -> [%pap-%pap] as reservation\n", + &phys, &start, &end); + return false; + } + + return true; +} + +/** + * 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 res; + 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) + continue; + + end = maps + size / sizeof(__be32); + + while (maps < end) { + struct device_node *np; + u32 phandle; + int na, ns; + + phandle = be32_to_cpup(maps++); + np = of_find_node_by_phandle(phandle); + na = of_n_addr_cells(np); + ns = of_n_size_cells(np); + + if (np == dev->of_node) { + int prot = IOMMU_READ | IOMMU_WRITE; + struct iommu_resv_region *region; + enum iommu_resv_type type; + phys_addr_t start; + size_t length; + + start = of_translate_dma_address(np, maps); + length = of_read_number(maps + na, ns); + + /* + * IOMMU regions without an associated physical region cannot be + * mapped and are simply reservations. + */ + if (res.end > res.start) { + phys_addr_t end = start + length - 1; + + if (check_direct_mapping(dev, &res, start, end)) + type = IOMMU_RESV_DIRECT_RELAXABLE; + else + type = IOMMU_RESV_RESERVED; + } 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 */