[PATCH 7/8] media: platform: exynos4-is: use DMA_ATTR_LOW_ADDRESS

From: Marek Szyprowski <m.szyprowski@samsung.com>
To: Linux IOMMU <iommu@lists.linux-foundation.org>,
	linux-media@vger.kernel.org, linux-samsung-soc@vger.kernel.org
Cc: Marek Szyprowski <m.szyprowski@samsung.com>,
	Robin Murphy <robin.murphy@arm.com>,
	Joerg Roedel <joro@8bytes.org>, Christoph Hellwig <hch@lst.de>,
	Sylwester Nawrocki <snawrocki@kernel.org>,
	Krzysztof Kozlowski <krzk@kernel.org>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
	Tomasz Figa <tfiga@chromium.org>,
	linux-kernel@vger.kernel.org
Subject: [PATCH 7/8] media: platform: exynos4-is: use DMA_ATTR_LOW_ADDRESS
Date: Fri, 25 Sep 2020 16:12:17 +0200	[thread overview]
Message-ID: <20200925141218.13550-8-m.szyprowski@samsung.com> (raw)
In-Reply-To: <20200925141218.13550-1-m.szyprowski@samsung.com>

Exynos4-IS driver relied on the way the ARM DMA-IOMMU glue code worked -
mainly it relied on the fact that the allocator used first-fit algorithm
and the first allocated buffer were at 0x0 DMA/IOVA address. This is not
true for the generic IOMMU-DMA glue code that will be used for ARM
architecture soon, so add the needed DMA attribute to force such behavior
of the DMA-mapping code.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/media/platform/exynos4-is/fimc-is.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/exynos4-is/fimc-is.c b/drivers/media/platform/exynos4-is/fimc-is.c
index 41b841a96338..9d3556eae5d3 100644
--- a/drivers/media/platform/exynos4-is/fimc-is.c
+++ b/drivers/media/platform/exynos4-is/fimc-is.c
@@ -335,8 +335,9 @@ static int fimc_is_alloc_cpu_memory(struct fimc_is *is)
 {
 	struct device *dev = &is->pdev->dev;
 
-	is->memory.vaddr = dma_alloc_coherent(dev, FIMC_IS_CPU_MEM_SIZE,
-					      &is->memory.addr, GFP_KERNEL);
+	is->memory.vaddr = dma_alloc_attrs(dev, FIMC_IS_CPU_MEM_SIZE,
+					   &is->memory.addr, GFP_KERNEL,
+					   DMA_ATTR_LOW_ADDRESS);
 	if (is->memory.vaddr == NULL)
 		return -ENOMEM;
 
-- 
2.17.1

