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SubjectRe: [PATCH v2 01/12] iommu/vt-d: Implement dma_[un]map_resource()
Oops, sorry. Please ignore the first two patches in this series. They
have already been merged independently.

Logan



On 2019-02-13 10:54 a.m., Logan Gunthorpe wrote:
> Currently the Intel IOMMU uses the default dma_[un]map_resource()
> implementations does nothing and simply returns the physical address
> unmodified.
>
> However, this doesn't create the IOVA entries necessary for addresses
> mapped this way to work when the IOMMU is enabled. Thus, when the
> IOMMU is enabled, drivers relying on dma_map_resource() will trigger
> DMAR errors. We see this when running ntb_transport with the IOMMU
> enabled, DMA, and switchtec hardware.
>
> The implementation for intel_map_resource() is nearly identical to
> intel_map_page(), we just have to re-create __intel_map_single().
> dma_unmap_resource() uses intel_unmap_page() directly as the
> functions are identical.
>
> Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
> Cc: David Woodhouse <dwmw2@infradead.org>
> Cc: Joerg Roedel <joro@8bytes.org>
> ---
> drivers/iommu/intel-iommu.c | 23 ++++++++++++++++-------
> 1 file changed, 16 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index 78188bf7e90d..ad737e16575b 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -3649,11 +3649,9 @@ static int iommu_no_mapping(struct device *dev)
> return 0;
> }
>
> -static dma_addr_t __intel_map_page(struct device *dev, struct page *page,
> - unsigned long offset, size_t size, int dir,
> - u64 dma_mask)
> +static dma_addr_t __intel_map_single(struct device *dev, phys_addr_t paddr,
> + size_t size, int dir, u64 dma_mask)
> {
> - phys_addr_t paddr = page_to_phys(page) + offset;
> struct dmar_domain *domain;
> phys_addr_t start_paddr;
> unsigned long iova_pfn;
> @@ -3715,7 +3713,15 @@ static dma_addr_t intel_map_page(struct device *dev, struct page *page,
> enum dma_data_direction dir,
> unsigned long attrs)
> {
> - return __intel_map_page(dev, page, offset, size, dir, *dev->dma_mask);
> + return __intel_map_single(dev, page_to_phys(page) + offset, size,
> + dir, *dev->dma_mask);
> +}
> +
> +static dma_addr_t intel_map_resource(struct device *dev, phys_addr_t phys_addr,
> + size_t size, enum dma_data_direction dir,
> + unsigned long attrs)
> +{
> + return __intel_map_single(dev, phys_addr, size, dir, *dev->dma_mask);
> }
>
> static void intel_unmap(struct device *dev, dma_addr_t dev_addr, size_t size)
> @@ -3806,8 +3812,9 @@ static void *intel_alloc_coherent(struct device *dev, size_t size,
> return NULL;
> memset(page_address(page), 0, size);
>
> - *dma_handle = __intel_map_page(dev, page, 0, size, DMA_BIDIRECTIONAL,
> - dev->coherent_dma_mask);
> + *dma_handle = __intel_map_single(dev, page_to_phys(page), size,
> + DMA_BIDIRECTIONAL,
> + dev->coherent_dma_mask);
> if (*dma_handle != DMA_MAPPING_ERROR)
> return page_address(page);
> if (!dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT))
> @@ -3924,6 +3931,8 @@ static const struct dma_map_ops intel_dma_ops = {
> .unmap_sg = intel_unmap_sg,
> .map_page = intel_map_page,
> .unmap_page = intel_unmap_page,
> + .map_resource = intel_map_resource,
> + .unmap_resource = intel_unmap_page,
> .dma_supported = dma_direct_supported,
> };
>
>

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