Add Xen stub of the map_peer_resource DMA API. Return an error to
indicate no bounce-buffer implementation is available yet.
Signed-off-by: Will Davis <wdavis@xxxxxxxxxx>
---
drivers/xen/swiotlb-xen.c | 20 ++++++++++++++++++++
include/xen/swiotlb-xen.h | 11 +++++++++++
2 files changed, 31 insertions(+)
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 4c54932..b9879dc 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -475,6 +475,26 @@ void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
}
EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_page);
+#ifdef CONFIG_HAS_DMA_P2P
+/*
+ * Maps a single region from a peer device's resource for DMA streaming. This is
+ * currently unimplemented for Xen because the only peer DMA mappings we're
+ * capable of creating are direct mappings with no explicit synchronization,
+ * e.g., there's no bounce buffer abstraction for peer mappings.
+ */
+dma_peer_addr_t xen_swiotlb_map_peer_resource(struct device *hwdev,
+ struct device *hwpeer,
+ struct resource *res,
+ unsigned long offset,
+ size_t size,
+ enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ return DMA_ERROR_CODE;
+}
+EXPORT_SYMBOL_GPL(xen_swiotlb_map_peer_resource);
+#endif
+
/*
* Make physical memory consistent for a single streaming mode DMA translation
* after a transfer.
diff --git a/include/xen/swiotlb-xen.h b/include/xen/swiotlb-xen.h
index 8b2eb93..dc08a4f 100644
--- a/include/xen/swiotlb-xen.h
+++ b/include/xen/swiotlb-xen.h
@@ -24,6 +24,17 @@ extern dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
extern void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
size_t size, enum dma_data_direction dir,
struct dma_attrs *attrs);
+
+#ifdef CONFIG_HAS_DMA_P2P
+extern dma_peer_addr_t xen_swiotlb_map_peer(struct device *hwdev,
+ struct device *hwpeer,
+ struct resource *res,
+ unsigned long offset,
+ size_t size,
+ enum dma_data_direction dir,
+ struct dma_attrs *attrs);
+#endif
+
extern int
xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
int nelems, enum dma_data_direction dir,
--
2.5.1
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