[PATCH 5/8] lib/scatterlist: Add sg_len helper

[Tadeusz Struk <tadeusz.struk@intel.com>]

Add sg_len function which returns the total number of bytes in sg.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
---
 include/linux/scatterlist.h |    1 +
 lib/scatterlist.c           |   18 ++++++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index 9b1ef0c..7c82fc1 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -246,6 +246,7 @@ static inline void *sg_virt(struct scatterlist *sg)
 }
 
 int sg_nents(struct scatterlist *sg);
+int sg_len(struct scatterlist *sg);
 int sg_nents_for_len(struct scatterlist *sg, u64 len);
 struct scatterlist *sg_next(struct scatterlist *);
 struct scatterlist *sg_last(struct scatterlist *s, unsigned int);
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index d105a9f..71324bb 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -57,6 +57,24 @@ int sg_nents(struct scatterlist *sg)
 EXPORT_SYMBOL(sg_nents);
 
 /**
+  * sg_len - return total size of bytes in the scatterlist
+  * @sg:         The scatterlist
+  *
+  * Description:
+  * Allows to know how the total size of bytes in sg, taking into acount
+  * chaining as well
+  **/
+int sg_len(struct scatterlist *sg)
+{
+	int len;
+
+	for (len = 0; sg; sg = sg_next(sg))
+		len += sg->length;
+	return len;
+}
+EXPORT_SYMBOL(sg_len);
+
+/**
  * sg_nents_for_len - return total count of entries in scatterlist
  *                    needed to satisfy the supplied length
  * @sg:		The scatterlist