[PATCH] lib/scatterlist: Provide scatterlist hexdump.

[chaohang.cheng]

From: "chaohang.cheng" <chaohang.cheng@xxxxxxxxxx>

A scatterlist hexdump is essential during debug, sometimes.

Signed-off-by: chaohang.cheng <chaohang.cheng@xxxxxxxxxx>
---
 include/linux/scatterlist.h | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index 7ff9d6386c12..ef8ecaac0016 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -563,4 +563,21 @@ bool sg_miter_skip(struct sg_mapping_iter *miter, off_t offset);
 bool sg_miter_next(struct sg_mapping_iter *miter);
 void sg_miter_stop(struct sg_mapping_iter *miter);
 
+/*
+ * Hexdump scatterlist
+ *
+ * @sg: struct scatterlist* .
+ * it stands for the head of a scatterlist .
+ *
+ * note: print_hex_dump_debug is a dynamic debug .
+ *
+ */
+#define SG_HEXDUMP(sg)							\
+do {									\
+	struct scatterlist *sg_tmp = NULL;				\
+	for (sg_tmp = sg; sg_tmp; sg_tmp = sg_next(sg_tmp))		\
+		print_hex_dump_debug("", DUMP_PREFIX_OFFSET,		\
+			16, 1, sg_virt(sg_tmp), sg_tmp->length, true);	\
+} while (0)
+
 #endif /* _LINUX_SCATTERLIST_H */
-- 
2.25.1