Map/Unmap a device MMIO resource from a physical address. If no dma_map_ops
method is available the operation is a no-op.
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
---
Documentation/DMA-API.txt | 22 +++++++++++++++++-----
include/linux/dma-mapping.h | 36 ++++++++++++++++++++++++++++++++++++
2 files changed, 53 insertions(+), 5 deletions(-)
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index 45ef3f2..c7e5f99 100644
--- a/Documentation/DMA-API.txt
+++ b/Documentation/DMA-API.txt
@@ -277,14 +277,26 @@ and <size> parameters are provided to do partial page mapping, it is
recommended that you never use these unless you really know what the
cache width is.
+dma_addr_t
+dma_map_resource(struct device *dev, phys_addr_t phys_addr, size_t size,
+ enum dma_data_direction dir, struct dma_attrs *attrs)
+
+void
+dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size,
+ enum dma_data_direction dir, struct dma_attrs *attrs)
+
+API for mapping and unmapping for MMIO resources. All the notes and
+warnings for the other mapping APIs apply here. The API should only be
+used to map device MMIO resources, mapping of RAM is not permitted.
+
int
dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
-In some circumstances dma_map_single() and dma_map_page() will fail to create
-a mapping. A driver can check for these errors by testing the returned
-DMA address with dma_mapping_error(). A non-zero return value means the mapping
-could not be created and the driver should take appropriate action (e.g.
-reduce current DMA mapping usage or delay and try again later).
+In some circumstances dma_map_single(), dma_map_page() and dma_map_resource()
+will fail to create a mapping. A driver can check for these errors by testing
+the returned DMA address with dma_mapping_error(). A non-zero return value
+means the mapping could not be created and the driver should take appropriate
+action (e.g. reduce current DMA mapping usage or delay and try again later).
int
dma_map_sg(struct device *dev, struct scatterlist *sg,
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index a11ff9d..4c381ba 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -218,6 +218,42 @@ static inline void dma_unmap_page(struct device *dev, dma_addr_t addr,
debug_dma_unmap_page(dev, addr, size, dir, false);
}
+static inline dma_addr_t dma_map_resource(struct device *dev,
+ phys_addr_t phys_addr,
+ size_t size,
+ enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ struct dma_map_ops *ops = get_dma_ops(dev);
+ unsigned long pfn = __phys_to_pfn(phys_addr);
+ dma_addr_t addr;
+
+ BUG_ON(!valid_dma_direction(dir));
+
+ /* Don't allow RAM to be mapped */
+ BUG_ON(pfn_valid(pfn));
+
+ addr = phys_addr;
+ if (ops->map_resource)
+ addr = ops->map_resource(dev, phys_addr, size, dir, attrs);
+
+ debug_dma_map_resource(dev, phys_addr, size, dir, addr);
+
+ return addr;
+}
+
+static inline void dma_unmap_resource(struct device *dev, dma_addr_t addr,
+ size_t size, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ struct dma_map_ops *ops = get_dma_ops(dev);
+
+ BUG_ON(!valid_dma_direction(dir));
+ if (ops->unmap_resource)
+ ops->unmap_resource(dev, addr, size, dir, attrs);
+ debug_dma_unmap_resource(dev, addr, size, dir);
+}
+
static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr,
size_t size,
enum dma_data_direction dir)
--
2.8.2
--
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