X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=crypto%2Fscatterwalk.c;h=79ca2278c2a38a6c022d7d3ccbae30981434e238;hb=fbc2edb05354480a88aa39db8a6acb5782fa1a1b;hp=7281b8a93ad3a4c486f3ca18721e73f79094659e;hpb=e644dae645e167d154c0526358940986682a72b0;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git

diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c
index 7281b8a..79ca227 100644
--- a/crypto/scatterwalk.c
+++ b/crypto/scatterwalk.c
@@ -124,3 +124,25 @@ void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
 	scatterwalk_done(&walk, out, 0);
 }
 EXPORT_SYMBOL_GPL(scatterwalk_map_and_copy);
+
+int scatterwalk_bytes_sglen(struct scatterlist *sg, int num_bytes)
+{
+	int offset = 0, n = 0;
+
+	/* num_bytes is too small */
+	if (num_bytes < sg->length)
+		return -1;
+
+	do {
+		offset += sg->length;
+		n++;
+		sg = scatterwalk_sg_next(sg);
+
+		/* num_bytes is too large */
+		if (unlikely(!sg && (num_bytes < offset)))
+			return -1;
+	} while (sg && (num_bytes > offset));
+
+	return n;
+}
+EXPORT_SYMBOL_GPL(scatterwalk_bytes_sglen);