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 7f3971d9fc5c..9239152abf7a 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;