[RFC PATCH v5 1/8] dma-mapping: add a device driver helper for iova contiguous

[Yoshihiro Shimoda]

This API can set a flag whether a device requires iova contiguous
strictly.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh at renesas.com>
---
 include/linux/device.h      |  1 +
 include/linux/dma-mapping.h | 16 ++++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/include/linux/device.h b/include/linux/device.h
index e85264f..a33d611 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -752,6 +752,7 @@ struct device_dma_parameters {
 	 */
 	unsigned int max_segment_size;
 	unsigned long segment_boundary_mask;
+	bool iova_contiguous;
 };
 
 /**
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 6309a72..cdb4e75 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -729,6 +729,22 @@ static inline int dma_set_seg_boundary(struct device *dev, unsigned long mask)
 	return -EIO;
 }
 
+static inline int dma_get_iova_contiguous(struct device *dev)
+{
+	if (dev->dma_parms)
+		return dev->dma_parms->iova_contiguous;
+	return false;
+}
+
+static inline int dma_set_iova_contiguous(struct device *dev, bool contiguous)
+{
+	if (dev->dma_parms) {
+		dev->dma_parms->iova_contiguous = contiguous;
+		return 0;
+	}
+	return -EIO;
+}
+
 #ifndef dma_max_pfn
 static inline unsigned long dma_max_pfn(struct device *dev)
 {
-- 
2.7.4