RDS: Implement atomic operations

Implement a CMSG-based interface to do FADD and CSWP ops.

Alter send routines to handle atomic ops.

Add atomic counters to stats.

Add xmit_atomic() to struct rds_transport

Inline rds_ib_send_unmap_rdma into unmap_rm

Signed-off-by: Andy Grover <andy.grover@oracle.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/include/linux/rds.h b/include/linux/rds.h
index 7f3971d..9239152 100644
--- a/include/linux/rds.h
+++ b/include/linux/rds.h
@@ -73,6 +73,8 @@
 #define RDS_CMSG_RDMA_MAP		3
 #define RDS_CMSG_RDMA_STATUS		4
 #define RDS_CMSG_CONG_UPDATE		5
+#define RDS_CMSG_ATOMIC_FADD		6
+#define RDS_CMSG_ATOMIC_CSWP		7
 
 #define RDS_INFO_FIRST			10000
 #define RDS_INFO_COUNTERS		10000
@@ -237,6 +239,23 @@ struct rds_rdma_args {
 	u_int64_t	user_token;
 };
 
+struct rds_atomic_args {
+	rds_rdma_cookie_t cookie;
+	uint64_t 	local_addr;
+	uint64_t 	remote_addr;
+	union {
+		struct {
+			uint64_t	compare;
+			uint64_t	swap;
+		} cswp;
+		struct {
+			uint64_t	add;
+		} fadd;
+	};
+	uint64_t	flags;
+	uint64_t	user_token;
+};
+
 struct rds_rdma_notify {
 	u_int64_t	user_token;
 	int32_t		status;