[PATCH v4 03/22] arm-ffa: add runtime-safe FF-A SMC wrapper

Add FF-A runtime annotations and expose invoke_ffa_fn_runtime() for code
that must remain available after ExitBootServices().

Provide implementations for the Arm FF-A driver and sandbox emulator so
later runtime direct-message helpers can use the same SMC entry point in
both environments.

Reviewed-by: Simon Glass <[email protected]>
Acked-by: Abdellatif El Khlifi <[email protected]>
Signed-off-by: Harsimran Singh Tungal <[email protected]>
---
 drivers/firmware/arm-ffa/arm-ffa.c         | 16 ++++++++-
 drivers/firmware/arm-ffa/ffa-emul-uclass.c | 12 +++++++
 include/arm_ffa_runtime.h                  | 41 ++++++++++++++++++++++
 3 files changed, 68 insertions(+), 1 deletion(-)
 create mode 100644 include/arm_ffa_runtime.h

diff --git a/drivers/firmware/arm-ffa/arm-ffa.c b/drivers/firmware/arm-ffa/arm-ffa.c
index 9e6b5dcc542..241ef018817 100644
--- a/drivers/firmware/arm-ffa/arm-ffa.c
+++ b/drivers/firmware/arm-ffa/arm-ffa.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
- * Copyright 2022-2023 Arm Limited and/or its affiliates <[email protected]>
+ * Copyright 2022-2023, 2026 Arm Limited and/or its affiliates <[email protected]>
  *
  * Authors:
  *   Abdellatif El Khlifi <[email protected]>
@@ -8,6 +8,7 @@
 
 #include <arm_ffa.h>
 #include <arm_ffa_priv.h>
+#include <arm_ffa_runtime.h>
 #include <dm.h>
 #include <log.h>
 #include <dm/device-internal.h>
@@ -25,6 +26,19 @@ void invoke_ffa_fn(ffa_value_t args, ffa_value_t *res)
 	arm_smccc_1_2_smc(&args, res);
 }
 
+/**
+ * invoke_ffa_fn_runtime() - Runtime-safe SMC wrapper
+ * @args: FF-A ABI arguments to be copied to Xn registers
+ * @res:  FF-A ABI return values copied from Xn registers
+ *
+ * Calls the SMCCC SMC 1.2 helper from EFI runtime context. This wrapper
+ * is marked __ffa_runtime so it remains available after ExitBootServices().
+ */
+void __ffa_runtime invoke_ffa_fn_runtime(ffa_value_t *args, ffa_value_t *res)
+{
+	arm_smccc_1_2_smc(args, res);
+}
+
 /**
  * arm_ffa_discover() - perform FF-A discovery
  * @dev: The Arm FF-A bus device (arm_ffa)
diff --git a/drivers/firmware/arm-ffa/ffa-emul-uclass.c b/drivers/firmware/arm-ffa/ffa-emul-uclass.c
index 6198d687354..d270f7b614e 100644
--- a/drivers/firmware/arm-ffa/ffa-emul-uclass.c
+++ b/drivers/firmware/arm-ffa/ffa-emul-uclass.c
@@ -671,6 +671,18 @@ void invoke_ffa_fn(ffa_value_t args, ffa_value_t *res)
 	sandbox_arm_ffa_smccc_smc(&args, res);
 }
 
+/**
+ * invoke_ffa_fn_runtime() - Runtime-safe SMC wrapper
+ * @args: FF-A ABI arguments to be copied to Xn registers
+ * @res: FF-A ABI return data to be copied from Xn registers
+ *
+ * Calls the emulated SMC call.
+ */
+void invoke_ffa_fn_runtime(ffa_value_t *args, ffa_value_t *res)
+{
+	sandbox_arm_ffa_smccc_smc(args, res);
+}
+
 /**
  * ffa_emul_find() - Find the FF-A emulator
  * @dev:	the sandbox FF-A device (sandbox-arm-ffa)
diff --git a/include/arm_ffa_runtime.h b/include/arm_ffa_runtime.h
new file mode 100644
index 00000000000..66096db3d24
--- /dev/null
+++ b/include/arm_ffa_runtime.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2026 Arm Limited and/or its affiliates <[email protected]>
+ *
+ * Authors:
+ *   Harsimran Singh Tungal <[email protected]>
+ *   Abdellatif El Khlifi <[email protected]>
+ */
+
+#ifndef __ARM_FFA_RUNTIME_H
+#define __ARM_FFA_RUNTIME_H
+
+#include <linux/types.h>
+#include <arm_ffa.h>
+#include <efi_loader.h>
+
+/**
+ *  __ffa_runtime - controls whether functions are
+ * available after calling the EFI ExitBootServices service.
+ * Functions tagged with these keywords are resident (available at boot time and
+ * at runtime)
+ */
+#if IS_ENABLED(CONFIG_ARM_FFA_RT_MODE)
+#define __ffa_runtime_data __efi_runtime_data
+#define __ffa_runtime __efi_runtime
+#else
+#define __ffa_runtime_data
+#define __ffa_runtime
+#endif
+
+/**
+ * invoke_ffa_fn_runtime() - Runtime-safe SMC wrapper
+ * @args: FF-A ABI arguments to be copied to Xn registers
+ * @res:  FF-A ABI return values copied from Xn registers
+ *
+ * Calls low level SMC implementation. This wrapper
+ * is marked __ffa_runtime so it remains available after ExitBootServices().
+ */
+void __ffa_runtime invoke_ffa_fn_runtime(ffa_value_t *args, ffa_value_t *res);
+
+#endif
-- 
2.34.1