RDS: Implement masked atomic operations

Add two CMSGs for masked versions of cswp and fadd. args
struct modified to use a union for different atomic op type's
arguments. Change IB to do masked atomic ops. Atomic op type
in rds_message similarly unionized.

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

4 files changed, 52 insertions, 13 deletions

diff --git a/net/rds/ib_send.c b/net/rds/ib_send.c
index 808544aebb70..71f373c421bc 100644
--- a/net/rds/ib_send.c
+++ b/net/rds/ib_send.c
@@ -807,13 +807,17 @@ int rds_ib_xmit_atomic(struct rds_connection *conn, struct rm_atomic_op *op)
         send->s_queued = jiffies;
 
         if (op->op_type == RDS_ATOMIC_TYPE_CSWP) {
-                send->s_wr.opcode = IB_WR_ATOMIC_CMP_AND_SWP;
-                send->s_wr.wr.atomic.compare_add = op->op_compare;
-                send->s_wr.wr.atomic.swap = op->op_swap_add;
+                send->s_wr.opcode = IB_WR_MASKED_ATOMIC_CMP_AND_SWP;
+                send->s_wr.wr.atomic.compare_add = op->op_m_cswp.compare;
+                send->s_wr.wr.atomic.swap = op->op_m_cswp.swap;
+                send->s_wr.wr.atomic.compare_add_mask = op->op_m_cswp.compare_mask;
+                send->s_wr.wr.atomic.swap_mask = op->op_m_cswp.swap_mask;
         } else { /* FADD */
-                send->s_wr.opcode = IB_WR_ATOMIC_FETCH_AND_ADD;
-                send->s_wr.wr.atomic.compare_add = op->op_swap_add;
+                send->s_wr.opcode = IB_WR_MASKED_ATOMIC_FETCH_AND_ADD;
+                send->s_wr.wr.atomic.compare_add = op->op_m_fadd.add;
                 send->s_wr.wr.atomic.swap = 0;
+                send->s_wr.wr.atomic.compare_add_mask = op->op_m_fadd.nocarry_mask;
+                send->s_wr.wr.atomic.swap_mask = 0;
         }
         nr_sig = rds_ib_set_wr_signal_state(ic, send, op->op_notify);
         send->s_wr.num_sge = 1;
diff --git a/net/rds/rdma.c b/net/rds/rdma.c
index 48781fe4431c..48064673fc76 100644
--- a/net/rds/rdma.c
+++ b/net/rds/rdma.c
@@ -738,13 +738,34 @@ int rds_cmsg_atomic(struct rds_sock *rs, struct rds_message *rm,
 
         args = CMSG_DATA(cmsg);
 
-        if (cmsg->cmsg_type == RDS_CMSG_ATOMIC_CSWP) {
-                rm->atomic.op_type = RDS_ATOMIC_TYPE_CSWP;
-                rm->atomic.op_swap_add = args->cswp.swap;
-                rm->atomic.op_compare = args->cswp.compare;
-        } else {
+        /* Nonmasked & masked cmsg ops converted to masked hw ops */
+        switch (cmsg->cmsg_type) {
+        case RDS_CMSG_ATOMIC_FADD:
+                rm->atomic.op_type = RDS_ATOMIC_TYPE_FADD;
+                rm->atomic.op_m_fadd.add = args->fadd.add;
+                rm->atomic.op_m_fadd.nocarry_mask = 0;
+                break;
+        case RDS_CMSG_MASKED_ATOMIC_FADD:
                 rm->atomic.op_type = RDS_ATOMIC_TYPE_FADD;
-                rm->atomic.op_swap_add = args->fadd.add;
+                rm->atomic.op_m_fadd.add = args->m_fadd.add;
+                rm->atomic.op_m_fadd.nocarry_mask = args->m_fadd.nocarry_mask;
+                break;
+        case RDS_CMSG_ATOMIC_CSWP:
+                rm->atomic.op_type = RDS_ATOMIC_TYPE_CSWP;
+                rm->atomic.op_m_cswp.compare = args->cswp.compare;
+                rm->atomic.op_m_cswp.swap = args->cswp.swap;
+                rm->atomic.op_m_cswp.compare_mask = ~0;
+                rm->atomic.op_m_cswp.swap_mask = ~0;
+                break;
+        case RDS_CMSG_MASKED_ATOMIC_CSWP:
+                rm->atomic.op_type = RDS_ATOMIC_TYPE_CSWP;
+                rm->atomic.op_m_cswp.compare = args->m_cswp.compare;
+                rm->atomic.op_m_cswp.swap = args->m_cswp.swap;
+                rm->atomic.op_m_cswp.compare_mask = args->m_cswp.compare_mask;
+                rm->atomic.op_m_cswp.swap_mask = args->m_cswp.swap_mask;
+                break;
+        default:
+                BUG(); /* should never happen */
         }
 
         rm->atomic.op_notify = !!(args->flags & RDS_RDMA_NOTIFY_ME);
diff --git a/net/rds/rds.h b/net/rds/rds.h
index aadaddba88a7..8103dcf8b976 100644
--- a/net/rds/rds.h
+++ b/net/rds/rds.h
@@ -316,8 +316,18 @@ struct rds_message {
         struct {
                 struct rm_atomic_op {
                         int                     op_type;
-                        uint64_t                op_swap_add;
-                        uint64_t                op_compare;
+                        union {
+                                struct {
+                                        uint64_t        compare;
+                                        uint64_t        swap;
+                                        uint64_t        compare_mask;
+                                        uint64_t        swap_mask;
+                                } op_m_cswp;
+                                struct {
+                                        uint64_t        add;
+                                        uint64_t        nocarry_mask;
+                                } op_m_fadd;
+                        };
 
                         u32                     op_rkey;
                         u64                     op_remote_addr;
diff --git a/net/rds/send.c b/net/rds/send.c
index 81471b25373b..9b951a0ab6b7 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -843,6 +843,8 @@ static int rds_rm_size(struct msghdr *msg, int data_len)
 
                 case RDS_CMSG_ATOMIC_CSWP:
                 case RDS_CMSG_ATOMIC_FADD:
+                case RDS_CMSG_MASKED_ATOMIC_CSWP:
+                case RDS_CMSG_MASKED_ATOMIC_FADD:
                         cmsg_groups |= 1;
                         size += sizeof(struct scatterlist);
                         break;
@@ -894,6 +896,8 @@ static int rds_cmsg_send(struct rds_sock *rs, struct rds_message *rm,
                         break;
                 case RDS_CMSG_ATOMIC_CSWP:
                 case RDS_CMSG_ATOMIC_FADD:
+                case RDS_CMSG_MASKED_ATOMIC_CSWP:
+                case RDS_CMSG_MASKED_ATOMIC_FADD:
                         ret = rds_cmsg_atomic(rs, rm, cmsg);
                         break;