[PATCH v4 3/8] dma-mapping: add dma_{map,unmap}_resource

From: Niklas SÃderlund
Date: Tue Feb 16 2016 - 15:40:30 EST


Map/Unmap a device resource from a physical address. If no dma_map_ops
method is available the operation is a no-op.

Signed-off-by: Niklas SÃderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
---
include/linux/dma-mapping.h | 32 ++++++++++++++++++++++++++++++++
1 file changed, 32 insertions(+)

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index e3aba4e..cc305d1 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -216,6 +216,38 @@ 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);
+
+ BUG_ON(!valid_dma_direction(dir));
+
+ /* Don't allow RAM to be mapped */
+ BUG_ON(pfn_valid(pfn));
+
+ if (ops->map_resource)
+ return ops->map_resource(dev, phys_addr, size, dir, attrs);
+
+ return phys_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);
+
+}
+
static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr,
size_t size,
enum dma_data_direction dir)
--
2.7.1