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-rw-r--r--include/linux/device.h11
-rw-r--r--include/linux/dma-mapping.h15
2 files changed, 26 insertions, 0 deletions
diff --git a/include/linux/device.h b/include/linux/device.h
index 479c0b31593c..2258d89bf523 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -410,6 +410,15 @@ extern int devres_release_group(struct device *dev, void *id);
extern void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp);
extern void devm_kfree(struct device *dev, void *p);
+struct device_dma_parameters {
+ /*
+ * a low level driver may set these to teach IOMMU code about
+ * sg limitations.
+ */
+ unsigned int max_segment_size;
+ unsigned long segment_boundary_mask;
+};
+
struct device {
struct klist klist_children;
struct klist_node knode_parent; /* node in sibling list */
@@ -445,6 +454,8 @@ struct device {
64 bit addresses for consistent
allocations such descriptors. */
+ struct device_dma_parameters *dma_parms;
+
struct list_head dma_pools; /* dma pools (if dma'ble) */
struct dma_coherent_mem *dma_mem; /* internal for coherent mem
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 4470950892be..df3a3610caf0 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -60,6 +60,21 @@ static inline int is_device_dma_capable(struct device *dev)
extern u64 dma_get_required_mask(struct device *dev);
+static inline unsigned int dma_get_max_seg_size(struct device *dev)
+{
+ return dev->dma_parms ? dev->dma_parms->max_segment_size : 65536;
+}
+
+static inline unsigned int dma_set_max_seg_size(struct device *dev,
+ unsigned int size)
+{
+ if (dev->dma_parms) {
+ dev->dma_parms->max_segment_size = size;
+ return 0;
+ } else
+ return -EIO;
+}
+
/* flags for the coherent memory api */
#define DMA_MEMORY_MAP 0x01
#define DMA_MEMORY_IO 0x02