From: m.szyprowski@samsung•com (Marek Szyprowski)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 3/9] ARM: dma-mapping: Always pass proper prot flags to iommu_map()
Date: Mon, 30 Sep 2013 15:40:58 +0200 [thread overview]
Message-ID: <52497F6A.2090505@samsung.com> (raw)
In-Reply-To: <1380234982-1677-4-git-send-email-andreas.herrmann@calxeda.com>
Hello,
On 2013-09-27 00:36, Andreas Herrmann wrote:
> ... otherwise it is impossible for the low level iommu driver to
> figure out which pte flags should be used.
>
> In __map_sg_chunk we can derive the flags from dma_data_direction.
>
> In __iommu_create_mapping we should treat the memory like
> DMA_BIDIRECTIONAL and pass both IOMMU_READ and IOMMU_WRITE to
> iommu_map.
> __iommu_create_mapping is used during dma_alloc_coherent (via
> arm_iommu_alloc_attrs). AFAIK dma_alloc_coherent is responsible for
> allocation _and_ mapping. I think this implies that access to the
> mapped pages should be allowed.
>
> Cc: Marek Szyprowski <m.szyprowski@samsung•com>
> Signed-off-by: Andreas Herrmann <andreas.herrmann@calxeda•com>
Thanks pointing the issue and preparing the patch. I will push it to the
dma-mapping fixes branch.
> ---
> arch/arm/mm/dma-mapping.c | 43 ++++++++++++++++++++++++++++---------------
> 1 file changed, 28 insertions(+), 15 deletions(-)
>
> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> index f5e1a84..1272ed2 100644
> --- a/arch/arm/mm/dma-mapping.c
> +++ b/arch/arm/mm/dma-mapping.c
> @@ -1232,7 +1232,8 @@ __iommu_create_mapping(struct device *dev, struct page **pages, size_t size)
> break;
>
> len = (j - i) << PAGE_SHIFT;
> - ret = iommu_map(mapping->domain, iova, phys, len, 0);
> + ret = iommu_map(mapping->domain, iova, phys, len,
> + IOMMU_READ|IOMMU_WRITE);
> if (ret < 0)
> goto fail;
> iova += len;
> @@ -1431,6 +1432,27 @@ static int arm_iommu_get_sgtable(struct device *dev, struct sg_table *sgt,
> GFP_KERNEL);
> }
>
> +static int __dma_direction_to_prot(enum dma_data_direction dir)
> +{
> + int prot;
> +
> + switch (dir) {
> + case DMA_BIDIRECTIONAL:
> + prot = IOMMU_READ | IOMMU_WRITE;
> + break;
> + case DMA_TO_DEVICE:
> + prot = IOMMU_READ;
> + break;
> + case DMA_FROM_DEVICE:
> + prot = IOMMU_WRITE;
> + break;
> + default:
> + prot = 0;
> + }
> +
> + return prot;
> +}
> +
> /*
> * Map a part of the scatter-gather list into contiguous io address space
> */
> @@ -1444,6 +1466,7 @@ static int __map_sg_chunk(struct device *dev, struct scatterlist *sg,
> int ret = 0;
> unsigned int count;
> struct scatterlist *s;
> + int prot;
>
> size = PAGE_ALIGN(size);
> *handle = DMA_ERROR_CODE;
> @@ -1460,7 +1483,9 @@ static int __map_sg_chunk(struct device *dev, struct scatterlist *sg,
> !dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
> __dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir);
>
> - ret = iommu_map(mapping->domain, iova, phys, len, 0);
> + prot = __dma_direction_to_prot(dir);
> +
> + ret = iommu_map(mapping->domain, iova, phys, len, prot);
> if (ret < 0)
> goto fail;
> count += len >> PAGE_SHIFT;
> @@ -1665,19 +1690,7 @@ static dma_addr_t arm_coherent_iommu_map_page(struct device *dev, struct page *p
> if (dma_addr == DMA_ERROR_CODE)
> return dma_addr;
>
> - switch (dir) {
> - case DMA_BIDIRECTIONAL:
> - prot = IOMMU_READ | IOMMU_WRITE;
> - break;
> - case DMA_TO_DEVICE:
> - prot = IOMMU_READ;
> - break;
> - case DMA_FROM_DEVICE:
> - prot = IOMMU_WRITE;
> - break;
> - default:
> - prot = 0;
> - }
> + prot = __dma_direction_to_prot(dir);
>
> ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, prot);
> if (ret < 0)
Best regards
--
Marek Szyprowski
Samsung R&D Institute Poland
next prev parent reply other threads:[~2013-09-30 13:40 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-26 22:36 [PATCH 0/9] arm-smmu: Misc changes/Calxeda ECX-2000 support Andreas Herrmann
2013-09-26 22:36 ` [PATCH 1/9] iommu/arm-smmu: Switch to arch_initcall for driver registration Andreas Herrmann
2013-09-27 8:58 ` Will Deacon
2013-09-27 9:24 ` Andreas Herrmann
2013-09-27 10:02 ` [PATCH] iommu/arm-smmu: Switch to subsys_initcall " Andreas Herrmann
2013-09-26 22:36 ` [PATCH 2/9] iommu/arm-smmu: Calculate SMMU_CB_BASE from smmu register values Andreas Herrmann
2013-09-27 9:51 ` Will Deacon
2013-09-27 10:23 ` Andreas Herrmann
2013-09-27 10:51 ` Will Deacon
2013-09-27 11:05 ` Andreas Herrmann
2013-09-27 11:08 ` Will Deacon
2013-09-27 14:33 ` [PATCH] iommu/arm-smmu: Refine check for proper size of mapped region Andreas Herrmann
2013-09-26 22:36 ` [PATCH 3/9] ARM: dma-mapping: Always pass proper prot flags to iommu_map() Andreas Herrmann
2013-09-27 8:35 ` Will Deacon
2013-09-30 13:40 ` Marek Szyprowski [this message]
2013-09-26 22:36 ` [PATCH 4/9] iommu/arm-smmu: Check for num_context_irqs > 0 to avoid divide by zero exception Andreas Herrmann
2013-09-27 8:41 ` Will Deacon
2013-09-27 9:03 ` Andreas Herrmann
2013-09-27 10:23 ` Will Deacon
2013-09-27 10:39 ` Andreas Herrmann
2013-09-27 10:48 ` Will Deacon
2013-09-27 11:07 ` Andreas Herrmann
2013-09-27 14:30 ` [PATCH] " Andreas Herrmann
2013-09-26 22:36 ` [PATCH 5/9] iommu/arm-smmu: Clear global and context bank fault status registers Andreas Herrmann
2013-09-27 8:52 ` Will Deacon
2013-09-30 13:54 ` Andreas Herrmann
2013-09-30 13:56 ` [PATCH] " Andreas Herrmann
2013-09-30 16:06 ` Will Deacon
2013-09-30 17:17 ` Andreas Herrmann
2013-09-30 18:30 ` Will Deacon
2013-09-30 21:06 ` Andreas Herrmann
2013-09-26 22:36 ` [PATCH 6/9] iommu/arm-smmu: Support buggy implemenations where all config accesses are secure Andreas Herrmann
2013-09-27 13:05 ` Will Deacon
2013-09-27 13:48 ` Andreas Herrmann
2013-09-26 22:36 ` [PATCH 7/9] iommu/arm-smmu: Add function that conditionally isolates all masters of all SMMUs Andreas Herrmann
2013-09-27 13:00 ` Will Deacon
2013-10-07 15:42 ` Andreas Herrmann
2013-10-08 10:43 ` Will Deacon
2013-09-26 22:36 ` [PATCH 8/9] iommu/arm-smmu: Introduce a default fault handler Andreas Herrmann
2013-09-27 10:09 ` Will Deacon
2013-09-27 10:45 ` Andreas Herrmann
2013-09-27 21:22 ` [PATCH] iommu/arm-smmu: Print context fault information Andreas Herrmann
2013-09-26 22:36 ` [PATCH 9/9] ARM: dts: Add nodes for SMMUs on Calxeda ECX-2000 Andreas Herrmann
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