Index: mlir/include/mlir/Dialect/Func/Transforms/Passes.h
===================================================================
--- mlir/include/mlir/Dialect/Func/Transforms/Passes.h
+++ mlir/include/mlir/Dialect/Func/Transforms/Passes.h
@@ -24,6 +24,11 @@
 
 class RewritePatternSet;
 
+// Options for Armv9 Streaming SVE mode. By default, streaming-mode is part of
+// the function interface (ABI) and the caller manages PSTATE.SM on entry/exit.
+// In a locally streaming function PSTATE.SM is kept internal and the callee
+// manages it on entry/exit.
+enum class ArmStreaming { Default = 0, Locally = 1 };
 
 #define GEN_PASS_DECL
 #include "mlir/Dialect/Func/Transforms/Passes.h.inc"
@@ -34,6 +39,10 @@
 /// Pass to deduplicate functions.
 std::unique_ptr<Pass> createDuplicateFunctionEliminationPass();
 
+/// Pass to enable Armv9 Streaming SVE mode.
+std::unique_ptr<Pass> createEnableArmStreamingPass();
+std::unique_ptr<Pass> createEnableArmStreamingPass(const ArmStreaming mode);
+
 //===----------------------------------------------------------------------===//
 // Registration
 //===----------------------------------------------------------------------===//
Index: mlir/include/mlir/Dialect/Func/Transforms/Passes.td
===================================================================
--- mlir/include/mlir/Dialect/Func/Transforms/Passes.td
+++ mlir/include/mlir/Dialect/Func/Transforms/Passes.td
@@ -51,4 +51,25 @@
   let constructor = "mlir::createDuplicateFunctionEliminationPass()";
 }
 
+def EnableArmStreaming
+    : Pass<"enable-arm-streaming", "mlir::func::FuncOp"> {
+  let summary = "Enable Armv9 Streaming SVE mode";
+  let description = [{
+    Enables the Armv9 Streaming SVE mode [1] for func.func ops by annotating
+    them with attributes. See options for more details.
+
+    [1] https://developer.arm.com/documentation/ddi0616/aa
+  }];
+  let constructor = "mlir::createEnableArmStreamingPass()";
+  let options = [
+    Option<"mode", "mode", "mlir::ArmStreaming",
+          /*default=*/"mlir::ArmStreaming::Default",
+          "Select how streaming-mode is managed at the function-level.",
+          [{::llvm::cl::values(
+            clEnumValN(::mlir::ArmStreaming::Default, "default", "Streaming mode is part of the function interface (ABI), caller manages PSTATE.SM on entry/exit."),
+            clEnumValN(::mlir::ArmStreaming::Locally, "locally", "Streaming mode is internal to the function, callee manages PSTATE.SM on entry/exit.")
+          )}]>,
+  ];
+}
+
 #endif // MLIR_DIALECT_FUNC_TRANSFORMS_PASSES_TD
Index: mlir/lib/Dialect/Func/Transforms/CMakeLists.txt
===================================================================
--- mlir/lib/Dialect/Func/Transforms/CMakeLists.txt
+++ mlir/lib/Dialect/Func/Transforms/CMakeLists.txt
@@ -4,6 +4,7 @@
   FuncBufferize.cpp
   FuncConversions.cpp
   OneToNFuncConversions.cpp
+  EnableArmStreaming.cpp
 
   ADDITIONAL_HEADER_DIRS
   ${MLIR_MAIN_INCLUDE_DIR}/mlir/Dialect/Func/Transforms
Index: mlir/lib/Dialect/Func/Transforms/EnableArmStreaming.cpp
===================================================================
--- /dev/null
+++ mlir/lib/Dialect/Func/Transforms/EnableArmStreaming.cpp
@@ -0,0 +1,79 @@
+//===- EnableArmStreaming.cpp - Enable Armv9 Streaming SVE mode -----------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass enables the Armv9 Scalable Matrix Extension (SME) Streaming SVE
+// (SSVE) mode [1][2] by adding either of the following attributes to
+// 'func.func' ops:
+//
+//   * 'arm_streaming' (default)
+//   * 'arm_locally_streaming'
+//
+// Streaming-mode is part of the interface (ABI) for functions with the
+// first attribute and it's the responsibility of the caller to manage
+// PSTATE.SM on entry/exit to functions with this attribute [3]. The LLVM
+// backend will emit 'smstart sm' / 'smstop sm' [4] around calls to
+// streaming functions.
+//
+// In locally streaming functions PSTATE.SM is kept internal and managed by
+// the callee on entry/exit. The LLVM backend will emit 'smstart sm' /
+// 'smstop sm' in the prologue / epilogue for functions with this
+// attribute.
+//
+// [1] https://developer.arm.com/documentation/ddi0616/aa
+// [2] https://llvm.org/docs/AArch64SME.html
+// [3] https://github.com/ARM-software/abi-aa/blob/main/aapcs64/aapcs64.rst#671pstatesm-interfaces
+// [4] https://developer.arm.com/documentation/ddi0602/2023-03/Base-Instructions/SMSTART--Enables-access-to-Streaming-SVE-mode-and-SME-architectural-state--an-alias-of-MSR--immediate--
+//
+//===----------------------------------------------------------------------===//
+
+#include "mlir/Dialect/Func/Transforms/Passes.h"
+
+#include "mlir/Dialect/Func/IR/FuncOps.h"
+
+#define DEBUG_TYPE "enable-arm-streaming"
+
+namespace mlir {
+#define GEN_PASS_DEF_ENABLEARMSTREAMING
+#include "mlir/Dialect/Func/Transforms/Passes.h.inc"
+} // namespace mlir
+
+using namespace mlir;
+using namespace mlir::func;
+
+static constexpr char kArmStreamingAttr[] = "arm_streaming";
+static constexpr char kArmLocallyStreamingAttr[] = "arm_locally_streaming";
+
+namespace {
+struct EnableArmStreamingPass
+    : public impl::EnableArmStreamingBase<EnableArmStreamingPass> {
+  EnableArmStreamingPass() = default;
+  EnableArmStreamingPass(const EnableArmStreamingPass &pass) = default;
+  EnableArmStreamingPass(mlir::ArmStreaming mode) { this->mode = mode; }
+  void runOnOperation() override {
+    std::string attr;
+    switch (mode) {
+    case ArmStreaming::Default:
+      attr = kArmStreamingAttr;
+      break;
+    case ArmStreaming::Locally:
+      attr = kArmLocallyStreamingAttr;
+      break;
+    }
+    getOperation()->setAttr(attr, UnitAttr::get(&getContext()));
+  }
+};
+} // namespace
+
+std::unique_ptr<Pass> mlir::createEnableArmStreamingPass() {
+  return std::make_unique<EnableArmStreamingPass>();
+}
+
+std::unique_ptr<Pass>
+mlir::createEnableArmStreamingPass(const mlir::ArmStreaming mode) {
+  return std::make_unique<EnableArmStreamingPass>(mode);
+}
Index: mlir/test/Dialect/Func/enable-arm-streaming.mlir
===================================================================
--- /dev/null
+++ mlir/test/Dialect/Func/enable-arm-streaming.mlir
@@ -0,0 +1,10 @@
+// RUN: mlir-opt %s -enable-arm-streaming -verify-diagnostics | FileCheck %s
+// RUN: mlir-opt %s -enable-arm-streaming=mode=locally -verify-diagnostics | FileCheck %s -check-prefix=CHECK-LOCALLY
+
+// CHECK-LABEL: @arm_streaming
+// CHECK-SAME: attributes {arm_streaming}
+func.func @arm_streaming() { return }
+
+// CHECK-LOCALLY-LABEL: @arm_locally_streaming
+// CHECK-LOCALLY-SAME: attributes {arm_locally_streaming}
+func.func @arm_locally_streaming() { return }