Introduce data structure used by both client and server to exchange
implementation details during RDMA/CM connection establishment.
This is an experimental out-of-band exchange between Linux
RPC-over-RDMA Version One implementations, replacing the deprecated
CCP (see RFC 5666bis). The purpose of this extension is to enable
prototyping of features that might be introduced in a subsequent
version of RPC-over-RDMA.
Suggested by Christoph Hellwig and Devesh Sharma.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Reviewed-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
---
include/linux/sunrpc/rpc_rdma.h | 35 +++++++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)
diff --git a/include/linux/sunrpc/rpc_rdma.h b/include/linux/sunrpc/rpc_rdma.h
index 3b1ff38..a7da6bf 100644
--- a/include/linux/sunrpc/rpc_rdma.h
+++ b/include/linux/sunrpc/rpc_rdma.h
@@ -41,6 +41,7 @@
#define _LINUX_SUNRPC_RPC_RDMA_H
#include <linux/types.h>
+#include <linux/bitops.h>
#define RPCRDMA_VERSION 1
#define rpcrdma_version cpu_to_be32(RPCRDMA_VERSION)
@@ -129,4 +130,38 @@ enum rpcrdma_proc {
#define rdma_done cpu_to_be32(RDMA_DONE)
#define rdma_error cpu_to_be32(RDMA_ERROR)
+/*
+ * Private extension to RPC-over-RDMA Version One.
+ * Message passed during RDMA-CM connection set-up.
+ *
+ * Add new fields at the end, and don't permute existing
+ * fields.
+ */
+struct rpcrdma_connect_private {
+ __be32 cp_magic;
+ u8 cp_version;
+ u8 cp_flags;
+ u8 cp_send_size;
+ u8 cp_recv_size;
+} __packed;
+
+#define rpcrdma_cmp_magic __cpu_to_be32(0xf6ab0e18)
+
+enum {
+ RPCRDMA_CMP_VERSION = 1,
+ RPCRDMA_CMP_F_SND_W_INV_OK = BIT(0),
+};
+
+static inline u8
+rpcrdma_encode_buffer_size(unsigned int size)
+{
+ return (size >> 10) - 1;
+}
+
+static inline unsigned int
+rpcrdma_decode_buffer_size(u8 val)
+{
+ return ((unsigned int)val + 1) << 10;
+}
+
#endif /* _LINUX_SUNRPC_RPC_RDMA_H */
--
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