1 files changed, 36 insertions, 34 deletions

diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index 457123171389..259735044148 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -150,7 +150,7 @@ static inline struct scatterlist *sg_last(struct scatterlist *sgl,
         struct scatterlist *ret = &sgl[nents - 1];
 #else
         struct scatterlist *sg, *ret = NULL;
-        int i;
+        unsigned int i;
 
         for_each_sg(sgl, sg, nents, i)
                 ret = sg;
@@ -179,48 +179,32 @@ static inline void sg_chain(struct scatterlist *prv, unsigned int prv_nents,
 #ifndef ARCH_HAS_SG_CHAIN
         BUG();
 #endif
-        prv[prv_nents - 1].page_link = (unsigned long) sgl | 0x01;
+        /*
+         * Set lowest bit to indicate a link pointer, and make sure to clear
+         * the termination bit if it happens to be set.
+         */
+        prv[prv_nents - 1].page_link = ((unsigned long) sgl | 0x01) & ~0x02;
 }
 
 /**
  * sg_mark_end - Mark the end of the scatterlist
- * @sgl:        Scatterlist
- * @nents:      Number of entries in sgl
+ * @sg:          SG entryScatterlist
  *
  * Description:
- *   Marks the last entry as the termination point for sg_next()
- *
- **/
-static inline void sg_mark_end(struct scatterlist *sgl, unsigned int nents)
-{
-        sgl[nents - 1].page_link = 0x02;
-}
-
-static inline void __sg_mark_end(struct scatterlist *sg)
-{
-        sg->page_link |= 0x02;
-}
-
-/**
- * sg_init_one - Initialize a single entry sg list
- * @sg:          SG entry
- * @buf:         Virtual address for IO
- * @buflen:      IO length
- *
- * Notes:
- *   This should not be used on a single entry that is part of a larger
- *   table. Use sg_init_table() for that.
+ *   Marks the passed in sg entry as the termination point for the sg
+ *   table. A call to sg_next() on this entry will return NULL.
  *
  **/
-static inline void sg_init_one(struct scatterlist *sg, const void *buf,
-                               unsigned int buflen)
+static inline void sg_mark_end(struct scatterlist *sg)
 {
-        memset(sg, 0, sizeof(*sg));
 #ifdef CONFIG_DEBUG_SG
-        sg->sg_magic = SG_MAGIC;
+        BUG_ON(sg->sg_magic != SG_MAGIC);
 #endif
-        sg_mark_end(sg, 1);
-        sg_set_buf(sg, buf, buflen);
+        /*
+         * Set termination bit, clear potential chain bit
+         */
+        sg->page_link |= 0x02;
+        sg->page_link &= ~0x01;
 }
 
 /**
@@ -236,14 +220,32 @@ static inline void sg_init_one(struct scatterlist *sg, const void *buf,
 static inline void sg_init_table(struct scatterlist *sgl, unsigned int nents)
 {
         memset(sgl, 0, sizeof(*sgl) * nents);
-        sg_mark_end(sgl, nents);
 #ifdef CONFIG_DEBUG_SG
         {
-                int i;
+                unsigned int i;
                 for (i = 0; i < nents; i++)
                         sgl[i].sg_magic = SG_MAGIC;
         }
 #endif
+        sg_mark_end(&sgl[nents - 1]);
+}
+
+/**
+ * sg_init_one - Initialize a single entry sg list
+ * @sg:          SG entry
+ * @buf:         Virtual address for IO
+ * @buflen:      IO length
+ *
+ * Notes:
+ *   This should not be used on a single entry that is part of a larger
+ *   table. Use sg_init_table() for that.
+ *
+ **/
+static inline void sg_init_one(struct scatterlist *sg, const void *buf,
+                               unsigned int buflen)
+{
+        sg_init_table(sg, 1);
+        sg_set_buf(sg, buf, buflen);
 }
 
 /**