From: joro@8bytes•org (Joerg Roedel)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2 1/2] iommu/dma: Implement dma_{map,unmap}_resource()
Date: Thu, 10 Nov 2016 13:24:20 +0100 [thread overview]
Message-ID: <20161110122420.GH9996@8bytes.org> (raw)
In-Reply-To: <4e84146ae49a4edd5f1226d76617be9aa92a58ee.1477503578.git.robin.murphy@arm.com>
On Wed, Oct 26, 2016 at 06:43:56PM +0100, Robin Murphy wrote:
> With the new dma_{map,unmap}_resource() functions added to the DMA API
> for the benefit of cases like slave DMA, add suitable implementations to
> the arsenal of our generic layer. Since cache maintenance should not be
> a concern, these can both be standalone callback implementations without
> the need for arch code wrappers.
>
> CC: Joerg Roedel <joro@8bytes•org>
> Signed-off-by: Robin Murphy <robin.murphy@arm•com>
> ---
>
> v2: Use iommu_dma_unmap_page for symmetry, instead of being sneaky.
>
> drivers/iommu/dma-iommu.c | 13 +++++++++++++
> include/linux/dma-iommu.h | 4 ++++
> 2 files changed, 17 insertions(+)
>
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index c5ab8667e6f2..a2fd90a6a782 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -624,6 +624,19 @@ void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
> __iommu_dma_unmap(iommu_get_domain_for_dev(dev), sg_dma_address(sg));
> }
>
> +dma_addr_t iommu_dma_map_resource(struct device *dev, phys_addr_t phys,
> + size_t size, enum dma_data_direction dir, unsigned long attrs)
> +{
> + return iommu_dma_map_page(dev, phys_to_page(phys), offset_in_page(phys),
> + size, dma_direction_to_prot(dir, false) | IOMMU_MMIO);
> +}
Isn't the whole point of map_resource that we can map regions which have
no 'struct page' associated? The use phys_to_page() will certainly not
do the right thing here.
Joerg
next prev parent reply other threads:[~2016-11-10 12:24 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-26 17:43 [PATCH v2 1/2] iommu/dma: Implement dma_{map,unmap}_resource() Robin Murphy
2016-10-26 17:43 ` [PATCH v2 2/2] arm64: Wire up iommu_dma_{map, unmap}_resource() Robin Murphy
2016-11-10 12:24 ` Joerg Roedel [this message]
2016-11-10 14:30 ` [PATCH v2 1/2] iommu/dma: Implement dma_{map,unmap}_resource() Robin Murphy
2016-11-10 18:37 ` Catalin Marinas
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