From patchwork Thu Sep 17 16:42:16 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robin Murphy X-Patchwork-Id: 7209131 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 861999F39B for ; Thu, 17 Sep 2015 16:44:17 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 88FAC207BA for ; Thu, 17 Sep 2015 16:44:16 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9640C207B8 for ; Thu, 17 Sep 2015 16:44:15 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZccGl-0006IS-KX; Thu, 17 Sep 2015 16:42:47 +0000 Received: from eu-smtp-delivery-143.mimecast.com ([146.101.78.143]) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZccGi-00068R-CZ for linux-arm-kernel@lists.infradead.org; Thu, 17 Sep 2015 16:42:45 +0000 Received: from cam-owa2.Emea.Arm.com (fw-tnat.cambridge.arm.com [217.140.96.140]) by eu-smtp-1.mimecast.com with ESMTP id uk-mta-5-Jp2IWkaBRz2geVOSDb5izA-1; Thu, 17 Sep 2015 17:42:20 +0100 Received: from e104324-lin.cambridge.arm.com ([10.1.2.79]) by cam-owa2.Emea.Arm.com with Microsoft SMTPSVC(6.0.3790.3959); Thu, 17 Sep 2015 17:42:19 +0100 From: Robin Murphy To: will.deacon@arm.com Subject: [PATCH v2] iommu/io-pgtable-arm: Don't use dma_to_phys() Date: Thu, 17 Sep 2015 17:42:16 +0100 Message-Id: <59f4ebbf06e75a6176a366495211afd16d0048a3.1442507940.git.robin.murphy@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1c591836f1ec6e676a8889cdccd042650eadb73b.1442499554.git.robin.murphy@arm.com> X-OriginalArrivalTime: 17 Sep 2015 16:42:19.0763 (UTC) FILETIME=[D1CE5430:01D0F167] X-MC-Unique: Jp2IWkaBRz2geVOSDb5izA-1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150917_094244_801697_94E846EF X-CRM114-Status: GOOD ( 11.34 ) X-Spam-Score: -5.2 (-----) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arm-kernel@lists.infradead.org, joro@8bytes.org, iommu@lists.linux-foundation.org, yong.wu@mediatek.com MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In checking whether DMA addresses differ from physical addresses, using dma_to_phys() is actually the wrong thing to do, since it may hide any DMA offset, which is precisely one of the things we are checking for. Simply casting between the two address types, whilst ugly, is in fact the appropriate course of action. Further care (and ugliness) is also necessary in the comparison to avoid truncation if phys_addr_t and dma_addr_t differ in size. We can also reject any device with a fixed DMA offset up-front at page table creation, leaving the allocation-time check for the more subtle cases like bounce buffering due to an incorrect DMA mask. Furthermore, we can then fix the hackish KConfig dependency so that architectures without a dma_to_phys() implementation may still COMPILE_TEST (or even use!) the code. The true dependency is on the DMA API, so use the appropriate symbol for that. Signed-off-by: Robin Murphy --- drivers/iommu/Kconfig | 3 +-- drivers/iommu/io-pgtable-arm.c | 24 +++++++++++++----------- 2 files changed, 14 insertions(+), 13 deletions(-) diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index 4664c2a..3dc1bcb 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -23,8 +23,7 @@ config IOMMU_IO_PGTABLE config IOMMU_IO_PGTABLE_LPAE bool "ARMv7/v8 Long Descriptor Format" select IOMMU_IO_PGTABLE - # SWIOTLB guarantees a dma_to_phys() implementation - depends on ARM || ARM64 || (COMPILE_TEST && SWIOTLB) + depends on HAS_DMA && (ARM || ARM64 || COMPILE_TEST) help Enable support for the ARM long descriptor pagetable format. This allocator supports 4K/2M/1G, 16K/32M and 64K/512M page diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c index 73c0748..96a4baa 100644 --- a/drivers/iommu/io-pgtable-arm.c +++ b/drivers/iommu/io-pgtable-arm.c @@ -202,9 +202,9 @@ typedef u64 arm_lpae_iopte; static bool selftest_running = false; -static dma_addr_t __arm_lpae_dma_addr(struct device *dev, void *pages) +static dma_addr_t __arm_lpae_dma_addr(void *pages) { - return phys_to_dma(dev, virt_to_phys(pages)); + return (dma_addr_t)virt_to_phys(pages); } static void *__arm_lpae_alloc_pages(size_t size, gfp_t gfp, @@ -223,10 +223,10 @@ static void *__arm_lpae_alloc_pages(size_t size, gfp_t gfp, goto out_free; /* * We depend on the IOMMU being able to work with any physical - * address directly, so if the DMA layer suggests it can't by - * giving us back some translation, that bodes very badly... + * address directly, so if the DMA layer suggests otherwise by + * translating or truncating them, that bodes very badly... */ - if (dma != __arm_lpae_dma_addr(dev, pages)) + if (dma != virt_to_phys(pages)) goto out_unmap; } @@ -243,10 +243,8 @@ out_free: static void __arm_lpae_free_pages(void *pages, size_t size, struct io_pgtable_cfg *cfg) { - struct device *dev = cfg->iommu_dev; - if (!selftest_running) - dma_unmap_single(dev, __arm_lpae_dma_addr(dev, pages), + dma_unmap_single(cfg->iommu_dev, __arm_lpae_dma_addr(pages), size, DMA_TO_DEVICE); free_pages_exact(pages, size); } @@ -254,12 +252,11 @@ static void __arm_lpae_free_pages(void *pages, size_t size, static void __arm_lpae_set_pte(arm_lpae_iopte *ptep, arm_lpae_iopte pte, struct io_pgtable_cfg *cfg) { - struct device *dev = cfg->iommu_dev; - *ptep = pte; if (!selftest_running) - dma_sync_single_for_device(dev, __arm_lpae_dma_addr(dev, ptep), + dma_sync_single_for_device(cfg->iommu_dev, + __arm_lpae_dma_addr(ptep), sizeof(pte), DMA_TO_DEVICE); } @@ -629,6 +626,11 @@ arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg) if (cfg->oas > ARM_LPAE_MAX_ADDR_BITS) return NULL; + if (cfg->iommu_dev->dma_pfn_offset) { + dev_err(cfg->iommu_dev, "Cannot accommodate DMA offset for IOMMU page tables\n"); + return NULL; + } + data = kmalloc(sizeof(*data), GFP_KERNEL); if (!data) return NULL;