tfm: Move tfm_ns_interface.c

tfm_ns_interface.c is intended to be overriden by clients to support
different targets. We copy this file from upstream into the mbed-os
platform library. We also have a specific "strong" overridden version
for the NU_M2354 target, which is located in its target library.
Previously the implementations in the platform library were decorated
with __attribute__(weak), and we provided a strong definition for the
NU_M2354 target. This worked fine because of weak linking, the linker
will pick the first "strong" definition and use that, avoiding any ODR
violations. However, upstream have removed __attribute__(weak) from the
function definitions, which caused multiply defined symbol errors when
trying to build the NU_M2354 target.

To work around the above issue, we remove the common definition in the
platform library; instead we copy the file to the Musca B1 and Musca S1
target libaries. This means the appropriate tfm_ns_interface.c is only
included in the build when compiling for the specific target which uses
it.

platform/FEATURE_EXPERIMENTAL_API/FEATURE_PSA/TARGET_TFM/TARGET_TFM_LATEST/CMakeLists.txt

@@ -18,7 +18,6 @@ if("TFM_V8M" IN_LIST MBED_TARGET_LABELS)
         INTERFACE
             TARGET_TFM_V8M/src/cmsis_nvic_virtual.c
             TARGET_TFM_V8M/src/tfm_mbed_boot.c
-            TARGET_TFM_V8M/src/tfm_ns_interface.c
             TARGET_TFM_V8M/src/tfm_psa_ns_api.c
     )
 endif()

targets/TARGET_ARM_SSG/TARGET_MUSCA_B1/CMakeLists.txt

@@ -43,6 +43,7 @@ target_sources(mbed-arm-musca-b1
         serial_api.c
         sleep_api.c
         tfm_ioctl_ns_api.c
+        tfm_ns_interface.c
         us_ticker.c
 
         device/device_definition.c

targets/TARGET_ARM_SSG/TARGET_MUSCA_S1/CMakeLists.txt

@@ -45,6 +45,7 @@ target_sources(mbed-arm-musca-s1
         serial_api.c
         sleep_api.c
         tfm_ioctl_ns_api.c
+        tfm_ns_interface.c
         us_ticker.c
 
         device/device_definition.c

targets/TARGET_ARM_SSG/TARGET_MUSCA_S1/tfm_ns_interface.c

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2017-2021, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+#include <stdint.h>
+
+#include "os_wrapper/mutex.h"
+
+#include "tfm_ns_interface.h"
+
+/**
+ * \brief the ns_lock ID
+ */
+static void *ns_lock_handle = NULL;
+
+int32_t tfm_ns_interface_dispatch(veneer_fn fn,
+                                  uint32_t arg0, uint32_t arg1,
+                                  uint32_t arg2, uint32_t arg3)
+{
+    int32_t result;
+
+    /* TFM request protected by NS lock */
+    while (os_wrapper_mutex_acquire(ns_lock_handle, OS_WRAPPER_WAIT_FOREVER)
+            != OS_WRAPPER_SUCCESS);
+
+    result = fn(arg0, arg1, arg2, arg3);
+
+    while (os_wrapper_mutex_release(ns_lock_handle) != OS_WRAPPER_SUCCESS);
+
+    return result;
+}
+
+uint32_t tfm_ns_interface_init(void)
+{
+    void *handle;
+
+    handle = os_wrapper_mutex_create();
+    if (!handle) {
+        return OS_WRAPPER_ERROR;
+    }
+
+    ns_lock_handle = handle;
+    return OS_WRAPPER_SUCCESS;
+}