From patchwork Tue Jun 15 13:27:08 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Claire Chang X-Patchwork-Id: 12321415 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5B2B2C48BE8 for ; Tue, 15 Jun 2021 13:28:44 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2DB416147E for ; Tue, 15 Jun 2021 13:28:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2DB416147E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7B58289FCC; Tue, 15 Jun 2021 13:28:43 +0000 (UTC) Received: from mail-pj1-x1033.google.com (mail-pj1-x1033.google.com [IPv6:2607:f8b0:4864:20::1033]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8CD696E062 for ; Tue, 15 Jun 2021 13:28:42 +0000 (UTC) Received: by mail-pj1-x1033.google.com with SMTP id mj8-20020a17090b3688b029016ee34fc1b3so1982523pjb.0 for ; Tue, 15 Jun 2021 06:28:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=r+B+WmWHIHMs91nx15AVM2itHN+i1YzQ775bO9+kHdU=; b=WzvexR7E+ALC8UHpMEnA+Cx3vlr1A1Cr5s3TW1YH4PposTtGKLhFpA/R/qQszzGPqE ordIiKc6mP07Rj60smVk6CJmnBRs8OEvLe0owSLDWKCjVANuxKyE3xs4HLfFTCYWWVik a6KT5EvKiBmg9I5cDjlQBmab8/PKoLLvYg/3Y= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=r+B+WmWHIHMs91nx15AVM2itHN+i1YzQ775bO9+kHdU=; b=bHeX4qY4IVwCubchScc62p+r4ZRvHqS1u+MkB070SvmoUdHlULh5zlWbuDUwD8Vb1v mnJmjfgqTETNsquU2sKBN/4bfJfQwuBAhjossyaRMMNbTxSAt3S05DDxx4kgG9j3Z+W8 daklt3P5BPSXDhtUBUF5wVgX/j8c8Z6IT7zKBPDNwCBzTwO3CqgGVHSqrgKj/dhIEsVV sQXAGesgBYeuMmV80AhNHqo5dG0bnU6sfjSlRlhyRoVtG+BbS8aTEKLoU6QJkJgrzCzu /9PICuGqxq6cFYaXbnKeTlhTtG05cLBlfifv3wcJ1gK6XdDTlq3ABQlLcu5//3RBSfVQ m8fQ== X-Gm-Message-State: AOAM530t0HXpwOYaOIcTpWr3mN1J2E4wf/rRqC3RH1n05VZ+dnSyUuOh 3CttTy6CbNz8xyDCJfY0J13elw== X-Google-Smtp-Source: ABdhPJxXGen/VsbHb/d7x2+yJI3KCk0Nmq9xnzsLjk06QOONO3j9/EsgGWLcwS/xwhPSaKB97/qqqw== X-Received: by 2002:a17:90b:19cd:: with SMTP id nm13mr5085576pjb.226.1623763722158; Tue, 15 Jun 2021 06:28:42 -0700 (PDT) Received: from localhost ([2401:fa00:95:205:1846:5274:e444:139e]) by smtp.gmail.com with UTF8SMTPSA id d8sm16002774pfq.198.2021.06.15.06.28.34 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 15 Jun 2021 06:28:41 -0700 (PDT) From: Claire Chang To: Rob Herring , mpe@ellerman.id.au, Joerg Roedel , Will Deacon , Frank Rowand , Konrad Rzeszutek Wilk , boris.ostrovsky@oracle.com, jgross@suse.com, Christoph Hellwig , Marek Szyprowski Subject: [PATCH v10 09/12] swiotlb: Add restricted DMA pool initialization Date: Tue, 15 Jun 2021 21:27:08 +0800 Message-Id: <20210615132711.553451-10-tientzu@chromium.org> X-Mailer: git-send-email 2.32.0.272.g935e593368-goog In-Reply-To: <20210615132711.553451-1-tientzu@chromium.org> References: <20210615132711.553451-1-tientzu@chromium.org> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: heikki.krogerus@linux.intel.com, thomas.hellstrom@linux.intel.com, peterz@infradead.org, dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk, grant.likely@arm.com, paulus@samba.org, mingo@kernel.org, jxgao@google.com, sstabellini@kernel.org, Saravana Kannan , xypron.glpk@gmx.de, "Rafael J . Wysocki" , Bartosz Golaszewski , bskeggs@redhat.com, linux-pci@vger.kernel.org, xen-devel@lists.xenproject.org, Thierry Reding , intel-gfx@lists.freedesktop.org, matthew.auld@intel.com, linux-devicetree , airlied@linux.ie, Robin Murphy , Nicolas Boichat , rodrigo.vivi@intel.com, bhelgaas@google.com, tientzu@chromium.org, Dan Williams , Andy Shevchenko , Greg KH , Randy Dunlap , lkml , tfiga@chromium.org, "list@263.net:IOMMU DRIVERS" , Jim Quinlan , linuxppc-dev@lists.ozlabs.org, bauerman@linux.ibm.com Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Add the initialization function to create restricted DMA pools from matching reserved-memory nodes. Regardless of swiotlb setting, the restricted DMA pool is preferred if available. The restricted DMA pools provide a basic level of protection against the DMA overwriting buffer contents at unexpected times. However, to protect against general data leakage and system memory corruption, the system needs to provide a way to lock down the memory access, e.g., MPU. Signed-off-by: Claire Chang --- include/linux/swiotlb.h | 3 +- kernel/dma/Kconfig | 14 ++++++++ kernel/dma/swiotlb.c | 78 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 94 insertions(+), 1 deletion(-) diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index efcd56e3a16c..e76ac46ffff9 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -73,7 +73,8 @@ extern enum swiotlb_force swiotlb_force; * range check to see if the memory was in fact allocated by this * API. * @nslabs: The number of IO TLB blocks (in groups of 64) between @start and - * @end. This is command line adjustable via setup_io_tlb_npages. + * @end. For default swiotlb, this is command line adjustable via + * setup_io_tlb_npages. * @used: The number of used IO TLB block. * @list: The free list describing the number of free entries available * from each index. diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig index 77b405508743..3e961dc39634 100644 --- a/kernel/dma/Kconfig +++ b/kernel/dma/Kconfig @@ -80,6 +80,20 @@ config SWIOTLB bool select NEED_DMA_MAP_STATE +config DMA_RESTRICTED_POOL + bool "DMA Restricted Pool" + depends on OF && OF_RESERVED_MEM + select SWIOTLB + help + This enables support for restricted DMA pools which provide a level of + DMA memory protection on systems with limited hardware protection + capabilities, such as those lacking an IOMMU. + + For more information see + + and . + If unsure, say "n". + # # Should be selected if we can mmap non-coherent mappings to userspace. # The only thing that is really required is a way to set an uncached bit diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 3c01162c400b..ef1ccd63534d 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -39,6 +39,13 @@ #ifdef CONFIG_DEBUG_FS #include #endif +#ifdef CONFIG_DMA_RESTRICTED_POOL +#include +#include +#include +#include +#include +#endif #include #include @@ -693,3 +700,74 @@ static int __init swiotlb_create_default_debugfs(void) late_initcall(swiotlb_create_default_debugfs); #endif + +#ifdef CONFIG_DMA_RESTRICTED_POOL +static int rmem_swiotlb_device_init(struct reserved_mem *rmem, + struct device *dev) +{ + struct io_tlb_mem *mem = rmem->priv; + unsigned long nslabs = rmem->size >> IO_TLB_SHIFT; + + /* + * Since multiple devices can share the same pool, the private data, + * io_tlb_mem struct, will be initialized by the first device attached + * to it. + */ + if (!mem) { + mem = kzalloc(struct_size(mem, slots, nslabs), GFP_KERNEL); + if (!mem) + return -ENOMEM; + + swiotlb_init_io_tlb_mem(mem, rmem->base, nslabs, false); + mem->force = true; + set_memory_decrypted((unsigned long)phys_to_virt(rmem->base), + rmem->size >> PAGE_SHIFT); + + rmem->priv = mem; + + if (IS_ENABLED(CONFIG_DEBUG_FS)) { + mem->debugfs = + debugfs_create_dir(rmem->name, debugfs_dir); + swiotlb_create_debugfs_files(mem); + } + } + + dev->dma_io_tlb_mem = mem; + + return 0; +} + +static void rmem_swiotlb_device_release(struct reserved_mem *rmem, + struct device *dev) +{ + dev->dma_io_tlb_mem = io_tlb_default_mem; +} + +static const struct reserved_mem_ops rmem_swiotlb_ops = { + .device_init = rmem_swiotlb_device_init, + .device_release = rmem_swiotlb_device_release, +}; + +static int __init rmem_swiotlb_setup(struct reserved_mem *rmem) +{ + unsigned long node = rmem->fdt_node; + + if (of_get_flat_dt_prop(node, "reusable", NULL) || + of_get_flat_dt_prop(node, "linux,cma-default", NULL) || + of_get_flat_dt_prop(node, "linux,dma-default", NULL) || + of_get_flat_dt_prop(node, "no-map", NULL)) + return -EINVAL; + + if (PageHighMem(pfn_to_page(PHYS_PFN(rmem->base)))) { + pr_err("Restricted DMA pool must be accessible within the linear mapping."); + return -EINVAL; + } + + rmem->ops = &rmem_swiotlb_ops; + pr_info("Reserved memory: created restricted DMA pool at %pa, size %ld MiB\n", + &rmem->base, (unsigned long)rmem->size / SZ_1M); + return 0; +} + +RESERVEDMEM_OF_DECLARE(dma, "restricted-dma-pool", rmem_swiotlb_setup); +#endif /* CONFIG_DMA_RESTRICTED_POOL */