[RFC PATCH v2 3/7] RDMA/rxe: Cleanup code for responder Atomic operations

Daisuke Matsuda
2022-11-11T09:25:08Z

Currently, rxe_responder() directly calls the function to execute Atomic
operations. This need to be modified to insert some conditional branches
for the new RDMA Write operation and the ODP feature.

Signed-off-by: Daisuke Matsuda <matsuda-daisuke@fujitsu.com>
---
drivers/infiniband/sw/rxe/rxe_resp.c | 102 +++++++++++++++++----------
1 file changed, 64 insertions(+), 38 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
index 91f935d60160..03e54cb37d44 100644
--- a/drivers/infiniband/sw/rxe/rxe_resp.c
+++ b/drivers/infiniband/sw/rxe/rxe_resp.c
@@ -595,60 +595,86 @@ static struct resp_res *rxe_prepare_res(struct rxe_qp *qp,
/* Guarantee atomicity of atomic operations at the machine level. */
static DEFINE_SPINLOCK(atomic_ops_lock);

-static enum resp_states atomic_reply(struct rxe_qp *qp,
- struct rxe_pkt_info *pkt)
+enum resp_states rxe_process_atomic(struct rxe_qp *qp,
+ struct rxe_pkt_info *pkt, u64 *vaddr)
{
- u64 *vaddr;
enum resp_states ret;
- struct rxe_mr *mr = qp->resp.mr;
struct resp_res *res = qp->resp.res;
u64 value;

- if (!res) {
- res = rxe_prepare_res(qp, pkt, RXE_ATOMIC_MASK);
- qp->resp.res = res;
+ /* check vaddr is 8 bytes aligned. */
+ if (!vaddr || (uintptr_t)vaddr & 7) {
+ ret = RESPST_ERR_MISALIGNED_ATOMIC;
+ goto out;
}

- if (!res->replay) {
- if (mr->state != RXE_MR_STATE_VALID) {
- ret = RESPST_ERR_RKEY_VIOLATION;
- goto out;
- }
+ spin_lock(&atomic_ops_lock);
+ res->atomic.orig_val = value = *vaddr;

- vaddr = iova_to_vaddr(mr, qp->resp.va + qp->resp.offset,
- sizeof(u64));
+ if (pkt->opcode == IB_OPCODE_RC_COMPARE_SWAP) {
+ if (value == atmeth_comp(pkt))
+ value = atmeth_swap_add(pkt);
+ } else {
+ value += atmeth_swap_add(pkt);
+ }

- /* check vaddr is 8 bytes aligned. */
- if (!vaddr || (uintptr_t)vaddr & 7) {
- ret = RESPST_ERR_MISALIGNED_ATOMIC;
- goto out;
- }
+ *vaddr = value;
+ spin_unlock(&atomic_ops_lock);

- spin_lock_bh(&atomic_ops_lock);
- res->atomic.orig_val = value = *vaddr;
+ qp->resp.msn++;

- if (pkt->opcode == IB_OPCODE_RC_COMPARE_SWAP) {
- if (value == atmeth_comp(pkt))
- value = atmeth_swap_add(pkt);
- } else {
- value += atmeth_swap_add(pkt);
- }
+ /* next expected psn, read handles this separately */
+ qp->resp.psn = (pkt->psn + 1) & BTH_PSN_MASK;
+ qp->resp.ack_psn = qp->resp.psn;

- *vaddr = value;
- spin_unlock_bh(&atomic_ops_lock);
+ qp->resp.opcode = pkt->opcode;
+ qp->resp.status = IB_WC_SUCCESS;

- qp->resp.msn++;
+ ret = RESPST_ACKNOWLEDGE;
+out:
+ return ret;
+}

- /* next expected psn, read handles this separately */
- qp->resp.psn = (pkt->psn + 1) & BTH_PSN_MASK;
- qp->resp.ack_psn = qp->resp.psn;
+static enum resp_states rxe_atomic_ops(struct rxe_qp *qp,
+ struct rxe_pkt_info *pkt,
+ struct rxe_mr *mr)
+{
+ u64 *vaddr;
+ int ret;

- qp->resp.opcode = pkt->opcode;
- qp->resp.status = IB_WC_SUCCESS;
+ vaddr = iova_to_vaddr(mr, qp->resp.va + qp->resp.offset,
+ sizeof(u64));
+
+ if (pkt->mask & RXE_ATOMIC_MASK) {
+ ret = rxe_process_atomic(qp, pkt, vaddr);
+ } else {
+ /*ATOMIC WRITE operation will come here. */
+ ret = RESPST_ERR_UNSUPPORTED_OPCODE;
}

- ret = RESPST_ACKNOWLEDGE;
-out:
+ return ret;
+}
+
+static enum resp_states rxe_atomic_reply(struct rxe_qp *qp,
+ struct rxe_pkt_info *pkt)
+{
+ struct rxe_mr *mr = qp->resp.mr;
+ struct resp_res *res = qp->resp.res;
+ int ret;
+
+ if (!res) {
+ res = rxe_prepare_res(qp, pkt, RXE_ATOMIC_MASK);
+ qp->resp.res = res;
+ }
+
+ if (!res->replay) {
+ if (mr->state != RXE_MR_STATE_VALID)
+ return RESPST_ERR_RKEY_VIOLATION;
+
+ ret = rxe_atomic_ops(qp, pkt, mr);
+ } else
+ ret = RESPST_ACKNOWLEDGE;
+
return ret;
}

@@ -1321,7 +1347,7 @@ int rxe_responder(void *arg)
state = read_reply(qp, pkt);
break;
case RESPST_ATOMIC_REPLY:
- state = atomic_reply(qp, pkt);
+ state = rxe_atomic_reply(qp, pkt);
break;
case RESPST_ACKNOWLEDGE:
state = acknowledge(qp, pkt);
--
2.31.1