[llvm] [OFFLOAD] Add missing data fence API for libomptarget migration (PR #172223)

[via llvm-commits]

https://github.com/fineg74 created https://github.com/llvm/llvm-project/pull/172223

Add missing liboffload data fence API for libomptarget migration

This PR adds liboffload data fence API that needed to make libomptarget to use liboffload

>From 87a0f3e3e3257799f846a15e467d2aa76e04fd8c Mon Sep 17 00:00:00 2001
From: "Fine, Gregory" <gregory.fine at intel.com>
Date: Fri, 12 Dec 2025 16:43:02 -0800
Subject: [PATCH] Add data fence API

---
 offload/liboffload/API/Queue.td        | 9 +++++++++
 offload/liboffload/src/OffloadImpl.cpp | 9 +++++++++
 2 files changed, 18 insertions(+)

diff --git a/offload/liboffload/API/Queue.td b/offload/liboffload/API/Queue.td
index ededa9cc92fef..40280fb013528 100644
--- a/offload/liboffload/API/Queue.td
+++ b/offload/liboffload/API/Queue.td
@@ -125,3 +125,12 @@ def olLaunchHostFunction : Function {
   ];
   let returns = [];
 }
+
+def olDataFence : Function {
+    let desc = "Insert a data fence between previous data operations and the following operations if necessary for the device.";
+    let details = [];
+    let params = [
+        Param<"ol_queue_handle_t", "Queue", "handle of the queue", PARAM_IN>
+    ];
+    let returns = [];
+}
diff --git a/offload/liboffload/src/OffloadImpl.cpp b/offload/liboffload/src/OffloadImpl.cpp
index eab9627217ca8..c82ec0cc02db4 100644
--- a/offload/liboffload/src/OffloadImpl.cpp
+++ b/offload/liboffload/src/OffloadImpl.cpp
@@ -1214,5 +1214,14 @@ Error olLaunchHostFunction_impl(ol_queue_handle_t Queue,
                                                 Queue->AsyncInfo);
 }
 
+Error olDataFence_impl(ol_queue_handle_t Queue) {
+  if (Queue->AsyncInfo->Queue) {
+    if (auto Err = Queue->Device->Device->dataFence(Queue->AsyncInfo))
+      return Err;
+  }
+
+  return Error::success();
+}
+
 } // namespace offload
 } // namespace llvm