arm_hal_interrupt.c

00001 /*
00002  * Copyright (c) 2016-2018 ARM Limited. All rights reserved.
00003  * SPDX-License-Identifier: Apache-2.0
00004  * Licensed under the Apache License, Version 2.0 (the License); you may
00005  * not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  * http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an AS IS BASIS, WITHOUT
00012  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 
00017 #include "arm_hal_interrupt.h"
00018 #include "arm_hal_interrupt_private.h"
00019 
00020 #if MBED_CONF_NANOSTACK_HAL_CRITICAL_SECTION_USABLE_FROM_INTERRUPT
00021 #include "platform/mbed_critical.h"
00022 #else
00023 #include "cmsis_os2.h"
00024 #include "mbed_rtos_storage.h"
00025 #endif
00026 
00027 #include <mbed_assert.h>
00028 
00029 
00030 // The critical section has two alternative implementations, the default which uses mutex
00031 // as locking primitive and the optional, which will bluntly disable interrupts
00032 // for the critical section. The mutex version will not cause issues by delaying
00033 // interrupts, but it has a down side that it can not be used from the interrupt
00034 // service routines. The IRQ-safe version will do the mutual exclusion by temporarily
00035 // disabling the interrupts, so it will have effect on interrupt latency.
00036 #if !MBED_CONF_NANOSTACK_HAL_CRITICAL_SECTION_USABLE_FROM_INTERRUPT
00037 
00038 static uint8_t sys_irq_disable_counter;
00039 
00040 static mbed_rtos_storage_mutex_t critical_mutex;
00041 static const osMutexAttr_t critical_mutex_attr = {
00042   .name = "nanostack_critical_mutex",
00043   .attr_bits = osMutexRecursive | osMutexPrioInherit | osMutexRobust,
00044   .cb_mem = &critical_mutex,
00045   .cb_size = sizeof critical_mutex,
00046 };
00047 static osMutexId_t critical_mutex_id;
00048 
00049 #endif
00050 
00051 void platform_critical_init(void)
00052 {
00053 #if MBED_CONF_NANOSTACK_HAL_CRITICAL_SECTION_USABLE_FROM_INTERRUPT
00054     // nothing to do here
00055 #else
00056     critical_mutex_id = osMutexNew(&critical_mutex_attr);
00057     MBED_ASSERT(critical_mutex_id);
00058 #endif
00059 }
00060 
00061 void platform_enter_critical(void)
00062 {
00063 #if MBED_CONF_NANOSTACK_HAL_CRITICAL_SECTION_USABLE_FROM_INTERRUPT
00064     core_util_critical_section_enter();
00065 #else
00066     osMutexAcquire(critical_mutex_id, osWaitForever);
00067     sys_irq_disable_counter++;
00068 #endif
00069 }
00070 
00071 void platform_exit_critical(void)
00072 {
00073 #if MBED_CONF_NANOSTACK_HAL_CRITICAL_SECTION_USABLE_FROM_INTERRUPT
00074     core_util_critical_section_exit();
00075 #else
00076     --sys_irq_disable_counter;
00077     osMutexRelease(critical_mutex_id);
00078 #endif
00079 }