mbed official / mbed-dev

mbed library sources. Supersedes mbed-src.

Dependents:   Nucleo_Hello_Encoder BLE_iBeaconScan AM1805_DEMO DISCO-F429ZI_ExportTemplate1 ... more

hal/mbed_critical_section_api.c@189:f392fc9709a3, 2019-02-20 (annotated)

Committer:
AnnaBridge
Date:
Wed Feb 20 22:31:08 2019 +0000
Revision:
189:f392fc9709a3
Parent:
188:bcfe06ba3d64 
mbed library release version 165

Who changed what in which revision?

UserRevisionLine numberNew contents of line
AnnaBridge 184:08ed48f1de7f 1 /* mbed Microcontroller Library
AnnaBridge 184:08ed48f1de7f 2 * Copyright (c) 2017 ARM Limited
AnnaBridge 189:f392fc9709a3 3 * SPDX-License-Identifier: Apache-2.0
AnnaBridge 184:08ed48f1de7f 4 *
AnnaBridge 184:08ed48f1de7f 5 * Licensed under the Apache License, Version 2.0 (the "License");
AnnaBridge 184:08ed48f1de7f 6 * you may not use this file except in compliance with the License.
AnnaBridge 184:08ed48f1de7f 7 * You may obtain a copy of the License at
AnnaBridge 184:08ed48f1de7f 8 *
AnnaBridge 184:08ed48f1de7f 9 * http://www.apache.org/licenses/LICENSE-2.0
AnnaBridge 184:08ed48f1de7f 10 *
AnnaBridge 184:08ed48f1de7f 11 * Unless required by applicable law or agreed to in writing, software
AnnaBridge 184:08ed48f1de7f 12 * distributed under the License is distributed on an "AS IS" BASIS,
AnnaBridge 184:08ed48f1de7f 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
AnnaBridge 184:08ed48f1de7f 14 * See the License for the specific language governing permissions and
AnnaBridge 184:08ed48f1de7f 15 * limitations under the License.
AnnaBridge 184:08ed48f1de7f 16 */
AnnaBridge 184:08ed48f1de7f 17 #include "cmsis.h"
AnnaBridge 184:08ed48f1de7f 18 #include "hal/critical_section_api.h"
AnnaBridge 184:08ed48f1de7f 19 #include "platform/mbed_assert.h"
AnnaBridge 184:08ed48f1de7f 20 #include "platform/mbed_toolchain.h"
AnnaBridge 184:08ed48f1de7f 21
AnnaBridge 184:08ed48f1de7f 22 #include <stdbool.h>
AnnaBridge 184:08ed48f1de7f 23
AnnaBridge 184:08ed48f1de7f 24 static volatile bool critical_interrupts_enabled = false;
AnnaBridge 184:08ed48f1de7f 25 static volatile bool state_saved = false;
AnnaBridge 184:08ed48f1de7f 26
AnnaBridge 184:08ed48f1de7f 27 static bool are_interrupts_enabled(void)
AnnaBridge 184:08ed48f1de7f 28 {
AnnaBridge 184:08ed48f1de7f 29 #if defined(__CORTEX_A9)
AnnaBridge 184:08ed48f1de7f 30 return ((__get_CPSR() & 0x80) == 0);
AnnaBridge 184:08ed48f1de7f 31 #else
AnnaBridge 184:08ed48f1de7f 32 return ((__get_PRIMASK() & 0x1) == 0);
AnnaBridge 184:08ed48f1de7f 33 #endif
AnnaBridge 184:08ed48f1de7f 34 }
AnnaBridge 184:08ed48f1de7f 35
AnnaBridge 184:08ed48f1de7f 36
AnnaBridge 184:08ed48f1de7f 37 MBED_WEAK void hal_critical_section_enter(void)
AnnaBridge 184:08ed48f1de7f 38 {
AnnaBridge 184:08ed48f1de7f 39 const bool interrupt_state = are_interrupts_enabled();
AnnaBridge 184:08ed48f1de7f 40
AnnaBridge 184:08ed48f1de7f 41 __disable_irq();
AnnaBridge 184:08ed48f1de7f 42
AnnaBridge 184:08ed48f1de7f 43 if (state_saved == true) {
AnnaBridge 184:08ed48f1de7f 44 return;
AnnaBridge 184:08ed48f1de7f 45 }
AnnaBridge 184:08ed48f1de7f 46
AnnaBridge 184:08ed48f1de7f 47 critical_interrupts_enabled = interrupt_state;
AnnaBridge 184:08ed48f1de7f 48 state_saved = true;
AnnaBridge 184:08ed48f1de7f 49 }
AnnaBridge 184:08ed48f1de7f 50
AnnaBridge 184:08ed48f1de7f 51 MBED_WEAK void hal_critical_section_exit(void)
AnnaBridge 184:08ed48f1de7f 52 {
AnnaBridge 184:08ed48f1de7f 53 // Interrupts must be disabled on invoking an exit from a critical section
AnnaBridge 184:08ed48f1de7f 54 MBED_ASSERT(!are_interrupts_enabled());
AnnaBridge 184:08ed48f1de7f 55 state_saved = false;
AnnaBridge 184:08ed48f1de7f 56
AnnaBridge 184:08ed48f1de7f 57 // Restore the IRQs to their state prior to entering the critical section
AnnaBridge 184:08ed48f1de7f 58 if (critical_interrupts_enabled == true) {
AnnaBridge 184:08ed48f1de7f 59 __enable_irq();
AnnaBridge 184:08ed48f1de7f 60 }
AnnaBridge 184:08ed48f1de7f 61 }
AnnaBridge 184:08ed48f1de7f 62
AnnaBridge 184:08ed48f1de7f 63 MBED_WEAK bool hal_in_critical_section(void)
AnnaBridge 184:08ed48f1de7f 64 {
AnnaBridge 184:08ed48f1de7f 65 return (state_saved == true);
AnnaBridge 184:08ed48f1de7f 66 }