[PATCH 07/18] bvec: add memcpy_{from, to}_bvec and memzero_bvec helper

[Christoph Hellwig]

Add helpers to perform common memory operation on a bvec.

Signed-off-by: Christoph Hellwig <hch at lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni at wdc.com>
Reviewed-by: Ira Weiny <ira.weiny at intel.com>
---
 include/linux/bvec.h | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/include/linux/bvec.h b/include/linux/bvec.h
index f8710af18eef..f9fa43b940ff 100644
--- a/include/linux/bvec.h
+++ b/include/linux/bvec.h
@@ -196,4 +196,37 @@ static inline void *bvec_kmap_local(struct bio_vec *bvec)
 	return kmap_local_page(bvec->bv_page) + bvec->bv_offset;
 }
 
+/**
+ * memcpy_from_bvec - copy data from a bvec
+ * @bvec: bvec to copy from
+ *
+ * Must be called on single-page bvecs only.
+ */
+static inline void memcpy_from_bvec(char *to, struct bio_vec *bvec)
+{
+	memcpy_from_page(to, bvec->bv_page, bvec->bv_offset, bvec->bv_len);
+}
+
+/**
+ * memcpy_to_bvec - copy data to a bvec
+ * @bvec: bvec to copy to
+ *
+ * Must be called on single-page bvecs only.
+ */
+static inline void memcpy_to_bvec(struct bio_vec *bvec, const char *from)
+{
+	memcpy_to_page(bvec->bv_page, bvec->bv_offset, from, bvec->bv_len);
+}
+
+/**
+ * memzero_bvec - zero all data in a bvec
+ * @bvec: bvec to zero
+ *
+ * Must be called on single-page bvecs only.
+ */
+static inline void memzero_bvec(struct bio_vec *bvec)
+{
+	memzero_page(bvec->bv_page, bvec->bv_offset, bvec->bv_len);
+}
+
 #endif /* __LINUX_BVEC_H */
-- 
2.30.2