efa: Add support to allocate thread domains

In order to optimize our CQ polling functions and QP posting functions,
implement the alloc/dealloc thread domain verb so the ULP will have
better control on the synchronization mechanisms EFA provider uses in
our data path functions.

Signed-off-by: Yonatan Nachum <[email protected]>

Author: YonatanNachum

providers/efa/efa.c

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
 /*
- * Copyright 2019-2024 Amazon.com, Inc. or its affiliates. All rights reserved.
+ * Copyright 2019-2025 Amazon.com, Inc. or its affiliates. All rights reserved.
  */
 
 #include <stdio.h>
@@ -28,13 +28,15 @@ static const struct verbs_match_ent efa_table[] = {
 
 static const struct verbs_context_ops efa_ctx_ops = {
 	.alloc_pd = efa_alloc_pd,
+	.alloc_td = efa_alloc_td,
 	.create_ah = efa_create_ah,
 	.create_cq = efa_create_cq,
 	.create_cq_ex = efa_create_cq_ex,
 	.create_qp = efa_create_qp,
 	.create_qp_ex = efa_create_qp_ex,
 	.cq_event = efa_cq_event,
 	.dealloc_pd = efa_dealloc_pd,
+	.dealloc_td = efa_dealloc_td,
 	.dereg_mr = efa_dereg_mr,
 	.destroy_ah = efa_destroy_ah,
 	.destroy_cq = efa_destroy_cq,

providers/efa/efa.h

@@ -53,6 +53,12 @@ struct efa_pd {
 	uint16_t pdn;
 };
 
+struct efa_td {
+	struct ibv_td ibvtd;
+	/* Number of parent domains referencing this TD */
+	atomic_int refcount;
+};
+
 struct efa_sub_cq {
 	uint16_t consumed_cnt;
 	int phase;
@@ -201,6 +207,11 @@ static inline struct efa_ah *to_efa_ah(struct ibv_ah *ibvah)
 	return container_of(ibvah, struct efa_ah, ibvah);
 }
 
+static inline struct efa_td *to_efa_td(struct ibv_td *ibvtd)
+{
+	return container_of(ibvtd, struct efa_td, ibvtd);
+}
+
 bool is_efa_dev(struct ibv_device *device);
 
 #endif /* __EFA_H__ */

providers/efa/verbs.c

@@ -2636,3 +2636,38 @@ int efa_destroy_ah(struct ibv_ah *ibvah)
 
 	return 0;
 }
+
+struct ibv_td *efa_alloc_td(struct ibv_context *ibvctx, struct ibv_td_init_attr *init_attr)
+{
+	struct efa_td *td;
+
+	if (!check_comp_mask(init_attr->comp_mask, 0)) {
+		verbs_err(verbs_get_ctx(ibvctx), "Invalid comp_mask\n");
+		errno = EOPNOTSUPP;
+		return NULL;
+	}
+
+	td = calloc(1, sizeof(*td));
+	if (!td) {
+		errno = ENOMEM;
+		return NULL;
+	}
+
+	td->ibvtd.context = ibvctx;
+	atomic_init(&td->refcount, 0);
+
+	return &td->ibvtd;
+}
+
+int efa_dealloc_td(struct ibv_td *ibvtd)
+{
+	struct efa_td *td;
+
+	td = to_efa_td(ibvtd);
+	if (atomic_load(&td->refcount) > 0)
+		return EBUSY;
+
+	free(td);
+
+	return 0;
+}

providers/efa/verbs.h

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause */
 /*
- * Copyright 2019-2023 Amazon.com, Inc. or its affiliates. All rights reserved.
+ * Copyright 2019-2025 Amazon.com, Inc. or its affiliates. All rights reserved.
  */
 
 #ifndef __EFA_VERBS_H__
@@ -50,5 +50,7 @@ int efa_post_recv(struct ibv_qp *ibvqp, struct ibv_recv_wr *wr,
 
 struct ibv_ah *efa_create_ah(struct ibv_pd *ibvpd, struct ibv_ah_attr *attr);
 int efa_destroy_ah(struct ibv_ah *ibvah);
+struct ibv_td *efa_alloc_td(struct ibv_context *ibvctx, struct ibv_td_init_attr *init_attr);
+int efa_dealloc_td(struct ibv_td *ibvtd);
 
 #endif /* __EFA_VERBS_H__ */