Merge pull request #2849 from pan-/fix_nordic_critical_section

Fix nordic critical section entry and exit

Author: sg-

features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/hal_patch/nordic_critical.c

@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2015-2016, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdint.h>                  // uint32_t, UINT32_MAX
+#include <assert.h>                  // uint32_t, UINT32_MAX
+#include "cmsis.h"
+#include "nrf_soc.h"
+#include "nrf_sdm.h"
+
+static union {
+    uint32_t _PRIMASK_state;
+    uint8_t  _sd_state;
+} _state = { 0 } ;
+static volatile uint32_t _entry_count = 0;
+static bool _use_softdevice_routine = false;
+
+void core_util_critical_section_enter()
+{
+    // if a critical section has already been entered, just update the counter
+    if (_entry_count) {
+        ++_entry_count;
+        return;
+    }
+
+    // in this path, a critical section has never been entered
+    uint32_t primask = __get_PRIMASK();
+
+    // if interrupts are enabled, try to use the soft device
+    uint8_t sd_enabled;
+    if ((primask == 0) && (sd_softdevice_is_enabled(&sd_enabled) == NRF_SUCCESS) && sd_enabled == 1) {
+        // if the soft device can be use, use it
+        sd_nvic_critical_region_enter(&_state._sd_state);
+        _use_softdevice_routine = true;
+    } else {
+        // if interrupts where enabled, disable them
+        if(primask == 0) {
+            __disable_irq();
+        }
+
+        // store the PRIMASK state, it will be restored at the end of the critical section
+        _state._PRIMASK_state = primask;
+        _use_softdevice_routine = false;
+    }
+
+    assert(_entry_count == 0); // entry count should always be equal to 0 at this point
+    ++_entry_count;
+}
+
+void core_util_critical_section_exit()
+{
+    assert(_entry_count > 0);
+    --_entry_count;
+
+    // If their is other segments which have entered the critical section, just leave
+    if (_entry_count) {
+        return;
+    }
+
+    // This is the last segment of the critical section, state should be restored as before entering
+    // the critical section
+    if (_use_softdevice_routine) {
+        sd_nvic_critical_region_exit(_state._sd_state);
+    } else {
+        __set_PRIMASK(_state._PRIMASK_state);
+    }
+}

hal/common/mbed_critical.c

@@ -19,6 +19,7 @@
 
 #include "cmsis.h"
 #include "mbed_assert.h"
+#include "toolchain.h"
 
 #define EXCLUSIVE_ACCESS (!defined (__CORTEX_M0) && !defined (__CORTEX_M0PLUS))
 
@@ -34,7 +35,7 @@ bool core_util_are_interrupts_enabled(void)
 #endif
 }
 
-void core_util_critical_section_enter(void)
+MBED_WEAK void core_util_critical_section_enter(void)
 {
     bool interrupts_disabled = !core_util_are_interrupts_enabled();
     __disable_irq();
@@ -59,7 +60,7 @@ void core_util_critical_section_enter(void)
     interrupt_enable_counter++;
 }
 
-void core_util_critical_section_exit(void)
+MBED_WEAK void core_util_critical_section_exit(void)
 {
     /* If critical_section_enter has not previously been called, do nothing */
     if (interrupt_enable_counter) {

hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/nordic_critical.c

@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2015-2016, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdint.h>                  // uint32_t, UINT32_MAX
+#include <assert.h>                  // uint32_t, UINT32_MAX
+#include "cmsis.h"
+#include "nrf_soc.h"
+#include "nrf_sdm.h"
+#include "nrf_nvic.h"
+
+static uint8_t  _sd_state = 0;
+static volatile uint32_t _entry_count = 0;
+
+void core_util_critical_section_enter()
+{
+    // if a critical section has already been entered, just update the counter
+    if (_entry_count) {
+        ++_entry_count;
+        return;
+    }
+
+    // in this path, a critical section has never been entered
+    // routine of SD V11 work even if the softdevice is not active
+    sd_nvic_critical_region_enter(&_sd_state);
+
+    assert(_entry_count == 0); // entry count should always be equal to 0 at this point
+    ++_entry_count;
+}
+
+void core_util_critical_section_exit()
+{
+    assert(_entry_count > 0);
+    --_entry_count;
+
+    // If their is other segments which have entered the critical section, just leave
+    if (_entry_count) {
+        return;
+    }
+
+    // This is the last segment of the critical section, state should be restored as before entering
+    // the critical section
+    sd_nvic_critical_region_exit(_sd_state);
+}