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From:   Sven Peter <sven@svenpeter.dev>
To:     iommu@lists.linux-foundation.org
Cc:     Sven Peter <sven@svenpeter.dev>, Joerg Roedel <joro@8bytes.org>,
        Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Arnd Bergmann <arnd@kernel.org>,
        Mohamed Mediouni <mohamed.mediouni@caramail.com>,
        Alexander Graf <graf@amazon.com>,
        Hector Martin <marcan@marcan.st>,
        Alyssa Rosenzweig <alyssa@rosenzweig.io>,
        linux-kernel@vger.kernel.org
Subject: [PATCH v2 3/8] iommu/dma: Disable get_sgtable for granule > PAGE_SIZE
Date:   Sat, 28 Aug 2021 17:36:37 +0200
Message-Id: <20210828153642.19396-4-sven@svenpeter.dev>
In-Reply-To: <20210828153642.19396-1-sven@svenpeter.dev>
References: <20210828153642.19396-1-sven@svenpeter.dev>
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Pretend that iommu_dma_get_sgtable is not implemented when
granule > PAGE_SIZE since I can neither test this function right now
nor do I fully understand how it is used.

Signed-off-by: Sven Peter <sven@svenpeter.dev>
---
 drivers/iommu/dma-iommu.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index d6e273ec3de6..64fbd9236820 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1315,9 +1315,15 @@ static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
 		void *cpu_addr, dma_addr_t dma_addr, size_t size,
 		unsigned long attrs)
 {
+	struct iommu_domain *domain = iommu_get_dma_domain(dev);
+	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+	struct iova_domain *iovad = &cookie->iovad;
 	struct page *page;
 	int ret;
 
+	if (iovad->granule > PAGE_SIZE)
+		return -ENXIO;
+
 	if (IS_ENABLED(CONFIG_DMA_REMAP) && is_vmalloc_addr(cpu_addr)) {
 		struct page **pages = dma_common_find_pages(cpu_addr);
 
-- 
2.25.1