From: Will Davis <wdavis@xxxxxxxxxx>
Implement 'map_resource' for the Intel IOMMU driver. Simply translate the
resource to a physical address and route it to the same handlers used by
the 'map_page' API.
This allows a device to map another's resource, to enable peer-to-peer
transactions.
Signed-off-by: Will Davis <wdavis@xxxxxxxxxx>
Reviewed-by: Terence Ripperda <tripperda@xxxxxxxxxx>
Reviewed-by: John Hubbard <jhubbard@xxxxxxxxxx>
---
drivers/iommu/intel-iommu.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 68d43be..0f49eff 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3095,6 +3095,15 @@ static dma_addr_t intel_map_page(struct device *dev, struct page *page,
dir, *dev->dma_mask);
}
+static dma_addr_t intel_map_resource(struct device *dev, struct resource *res,
+ unsigned long offset, size_t size,
+ enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ return __intel_map_single(dev, res->start + offset, size,
+ dir, *dev->dma_mask);
+}
+
static void flush_unmaps(void)
{
int i, j;
@@ -3226,6 +3235,13 @@ static void intel_unmap_page(struct device *dev, dma_addr_t dev_addr,
intel_unmap(dev, dev_addr);
}
+static void intel_unmap_resource(struct device *dev, dma_addr_t dev_addr,
+ size_t size, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ intel_unmap(dev, dev_addr);
+}
+
static void *intel_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flags,
struct dma_attrs *attrs)
@@ -3382,6 +3398,8 @@ 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_resource,
.mapping_error = intel_mapping_error,
};
--
2.4.0
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