svcrdma: Add common XDR encoders for RDMA and Read segments

Clean up: De-duplicate some code.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

include/linux/sunrpc/rpc_rdma.h

@@ -124,6 +124,43 @@ rpcrdma_decode_buffer_size(u8 val)
 	return ((unsigned int)val + 1) << 10;
 }
 
+/**
+ * xdr_encode_rdma_segment - Encode contents of an RDMA segment
+ * @p: Pointer into a send buffer
+ * @handle: The RDMA handle to encode
+ * @length: The RDMA length to encode
+ * @offset: The RDMA offset to encode
+ *
+ * Return value:
+ *   Pointer to the XDR position that follows the encoded RDMA segment
+ */
+static inline __be32 *xdr_encode_rdma_segment(__be32 *p, u32 handle,
+					      u32 length, u64 offset)
+{
+	*p++ = cpu_to_be32(handle);
+	*p++ = cpu_to_be32(length);
+	return xdr_encode_hyper(p, offset);
+}
+
+/**
+ * xdr_encode_read_segment - Encode contents of a Read segment
+ * @p: Pointer into a send buffer
+ * @position: The position to encode
+ * @handle: The RDMA handle to encode
+ * @length: The RDMA length to encode
+ * @offset: The RDMA offset to encode
+ *
+ * Return value:
+ *   Pointer to the XDR position that follows the encoded Read segment
+ */
+static inline __be32 *xdr_encode_read_segment(__be32 *p, u32 position,
+					      u32 handle, u32 length,
+					      u64 offset)
+{
+	*p++ = cpu_to_be32(position);
+	return xdr_encode_rdma_segment(p, handle, length, offset);
+}
+
 /**
  * xdr_decode_rdma_segment - Decode contents of an RDMA segment
  * @p: Pointer to the undecoded RDMA segment

net/sunrpc/xprtrdma/rpc_rdma.c

@@ -275,14 +275,6 @@ rpcrdma_convert_iovs(struct rpcrdma_xprt *r_xprt, struct xdr_buf *xdrbuf,
 	return n;
 }
 
-static void
-xdr_encode_rdma_segment(__be32 *iptr, struct rpcrdma_mr *mr)
-{
-	*iptr++ = cpu_to_be32(mr->mr_handle);
-	*iptr++ = cpu_to_be32(mr->mr_length);
-	xdr_encode_hyper(iptr, mr->mr_offset);
-}
-
 static int
 encode_rdma_segment(struct xdr_stream *xdr, struct rpcrdma_mr *mr)
 {
@@ -292,7 +284,7 @@ encode_rdma_segment(struct xdr_stream *xdr, struct rpcrdma_mr *mr)
 	if (unlikely(!p))
 		return -EMSGSIZE;
 
-	xdr_encode_rdma_segment(p, mr);
+	xdr_encode_rdma_segment(p, mr->mr_handle, mr->mr_length, mr->mr_offset);
 	return 0;
 }
 
@@ -307,8 +299,8 @@ encode_read_segment(struct xdr_stream *xdr, struct rpcrdma_mr *mr,
 		return -EMSGSIZE;
 
 	*p++ = xdr_one;			/* Item present */
-	*p++ = cpu_to_be32(position);
-	xdr_encode_rdma_segment(p, mr);
+	xdr_encode_read_segment(p, position, mr->mr_handle, mr->mr_length,
+				mr->mr_offset);
 	return 0;
 }
 

net/sunrpc/xprtrdma/svc_rdma_sendto.c

@@ -376,7 +376,6 @@ static ssize_t svc_rdma_encode_write_segment(__be32 *src,
 
 	xdr_decode_rdma_segment(src, &handle, &length, &offset);
 
-	*p++ = cpu_to_be32(handle);
 	if (*remaining < length) {
 		/* segment only partly filled */
 		length = *remaining;
@@ -385,8 +384,7 @@ static ssize_t svc_rdma_encode_write_segment(__be32 *src,
 		/* entire segment was consumed */
 		*remaining -= length;
 	}
-	*p++ = cpu_to_be32(length);
-	xdr_encode_hyper(p, offset);
+	xdr_encode_rdma_segment(p, handle, length, offset);
 
 	trace_svcrdma_encode_wseg(handle, length, offset);
 	return len;