[PATCH 1/4] iommu/exynos: Set correct dma mask for SysMMU v5+

From: Sam Protsenko <semen.protsenko@linaro.org>
To: Marek Szyprowski <m.szyprowski@samsung.com>,
	Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Janghyuck Kim <janghyuck.kim@samsung.com>,
	linux-samsung-soc@vger.kernel.org, Will Deacon <will@kernel.org>,
	iommu@lists.linux.dev, linux-kernel@vger.kernel.org,
	iommu@lists.linux-foundation.org,
	Cho KyongHo <pullip.cho@samsung.com>,
	Robin Murphy <robin.murphy@arm.com>,
	Sumit Semwal <sumit.semwal@linaro.org>,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/4] iommu/exynos: Set correct dma mask for SysMMU v5+
Date: Sun,  3 Jul 2022 00:37:21 +0300	[thread overview]
Message-ID: <20220702213724.3949-2-semen.protsenko@linaro.org> (raw)
In-Reply-To: <20220702213724.3949-1-semen.protsenko@linaro.org>

SysMMU v5+ supports 36 bit physical address space. Set corresponding DMA
mask to avoid falling back to SWTLBIO usage in dma_map_single() because
of failed dma_capable() check.

The original code for this fix was suggested by Marek.

Originally-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
---
 drivers/iommu/exynos-iommu.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index 71f2018e23fe..28f8c8d93aa3 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -647,6 +647,14 @@ static int exynos_sysmmu_probe(struct platform_device *pdev)
 		}
 	}
 
+	if (MMU_MAJ_VER(data->version) >= 5) {
+		ret = dma_set_mask(dev, DMA_BIT_MASK(36));
+		if (ret) {
+			dev_err(dev, "Unable to set DMA mask: %d\n", ret);
+			return ret;
+		}
+	}
+
 	/*
 	 * use the first registered sysmmu device for performing
 	 * dma mapping operations on iommu page tables (cpu cache flush)
-- 
2.30.2

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