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@184:08ed48f1de7f, 2018-04-19 (annotated)

Committer:
AnnaBridge
Date:
Thu Apr 19 17:12:19 2018 +0100
Revision:
184:08ed48f1de7f
Child:
188:bcfe06ba3d64
mbed-dev library. Release version 161

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 184:08ed48f1de7f 3 *
AnnaBridge 184:08ed48f1de7f 4 * Licensed under the Apache License, Version 2.0 (the "License");
AnnaBridge 184:08ed48f1de7f 5 * you may not use this file except in compliance with the License.
AnnaBridge 184:08ed48f1de7f 6 * You may obtain a copy of the License at
AnnaBridge 184:08ed48f1de7f 7 *
AnnaBridge 184:08ed48f1de7f 8 * http://www.apache.org/licenses/LICENSE-2.0
AnnaBridge 184:08ed48f1de7f 9 *
AnnaBridge 184:08ed48f1de7f 10 * Unless required by applicable law or agreed to in writing, software
AnnaBridge 184:08ed48f1de7f 11 * distributed under the License is distributed on an "AS IS" BASIS,
AnnaBridge 184:08ed48f1de7f 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
AnnaBridge 184:08ed48f1de7f 13 * See the License for the specific language governing permissions and
AnnaBridge 184:08ed48f1de7f 14 * limitations under the License.
AnnaBridge 184:08ed48f1de7f 15 */
AnnaBridge 184:08ed48f1de7f 16 #include "cmsis.h"
AnnaBridge 184:08ed48f1de7f 17 #include "hal/critical_section_api.h"
AnnaBridge 184:08ed48f1de7f 18 #include "platform/mbed_assert.h"
AnnaBridge 184:08ed48f1de7f 19 #include "platform/mbed_toolchain.h"
AnnaBridge 184:08ed48f1de7f 20
AnnaBridge 184:08ed48f1de7f 21 #include <stdbool.h>
AnnaBridge 184:08ed48f1de7f 22
AnnaBridge 184:08ed48f1de7f 23 static volatile bool critical_interrupts_enabled = false;
AnnaBridge 184:08ed48f1de7f 24 static volatile bool state_saved = false;
AnnaBridge 184:08ed48f1de7f 25
AnnaBridge 184:08ed48f1de7f 26 static bool are_interrupts_enabled(void)
AnnaBridge 184:08ed48f1de7f 27 {
AnnaBridge 184:08ed48f1de7f 28 #if defined(__CORTEX_A9)
AnnaBridge 184:08ed48f1de7f 29 return ((__get_CPSR() & 0x80) == 0);
AnnaBridge 184:08ed48f1de7f 30 #else
AnnaBridge 184:08ed48f1de7f 31 return ((__get_PRIMASK() & 0x1) == 0);
AnnaBridge 184:08ed48f1de7f 32 #endif
AnnaBridge 184:08ed48f1de7f 33 }
AnnaBridge 184:08ed48f1de7f 34
AnnaBridge 184:08ed48f1de7f 35
AnnaBridge 184:08ed48f1de7f 36 MBED_WEAK void hal_critical_section_enter(void)
AnnaBridge 184:08ed48f1de7f 37 {
AnnaBridge 184:08ed48f1de7f 38 const bool interrupt_state = are_interrupts_enabled();
AnnaBridge 184:08ed48f1de7f 39
AnnaBridge 184:08ed48f1de7f 40 __disable_irq();
AnnaBridge 184:08ed48f1de7f 41
AnnaBridge 184:08ed48f1de7f 42 if (state_saved == true) {
AnnaBridge 184:08ed48f1de7f 43 return;
AnnaBridge 184:08ed48f1de7f 44 }
AnnaBridge 184:08ed48f1de7f 45
AnnaBridge 184:08ed48f1de7f 46 critical_interrupts_enabled = interrupt_state;
AnnaBridge 184:08ed48f1de7f 47 state_saved = true;
AnnaBridge 184:08ed48f1de7f 48 }
AnnaBridge 184:08ed48f1de7f 49
AnnaBridge 184:08ed48f1de7f 50 MBED_WEAK void hal_critical_section_exit(void)
AnnaBridge 184:08ed48f1de7f 51 {
AnnaBridge 184:08ed48f1de7f 52 #ifndef FEATURE_UVISOR
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 #endif
AnnaBridge 184:08ed48f1de7f 56 state_saved = false;
AnnaBridge 184:08ed48f1de7f 57
AnnaBridge 184:08ed48f1de7f 58 // Restore the IRQs to their state prior to entering the critical section
AnnaBridge 184:08ed48f1de7f 59 if (critical_interrupts_enabled == true) {
AnnaBridge 184:08ed48f1de7f 60 __enable_irq();
AnnaBridge 184:08ed48f1de7f 61 }
AnnaBridge 184:08ed48f1de7f 62 }
AnnaBridge 184:08ed48f1de7f 63
AnnaBridge 184:08ed48f1de7f 64 MBED_WEAK bool hal_in_critical_section(void)
AnnaBridge 184:08ed48f1de7f 65 {
AnnaBridge 184:08ed48f1de7f 66 return (state_saved == true);
AnnaBridge 184:08ed48f1de7f 67 }