mirror of https://github.com/ARMmbed/mbed-os.git
74 lines
2.4 KiB
C
74 lines
2.4 KiB
C
/*
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* Copyright (c) 2015-2016, ARM Limited, All Rights Reserved
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed under the Apache License, Version 2.0 (the "License"); you may
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* not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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// This critical section implementation is generic for mbed OS targets,
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// except Nordic ones
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#if defined(TARGET_LIKE_MBED) && !defined(TARGET_NORDIC)
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#include <stdint.h>
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#include <stddef.h>
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#include "cmsis.h"
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#include <assert.h>
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// Module include
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#include "critical.h"
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static volatile uint32_t interrupt_enable_counter = 0;
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static volatile uint32_t critical_primask = 0;
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void core_util_critical_section_enter()
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{
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uint32_t primask = __get_PRIMASK(); /* get the current interrupt enabled state */
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__disable_irq();
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/* Save the interrupt enabled state as it was prior to any nested critical section lock use */
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if (!interrupt_enable_counter) {
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critical_primask = primask & 0x1;
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}
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/* If the interrupt_enable_counter overflows or we are in a nested critical section and interrupts
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are enabled, then something has gone badly wrong thus assert an error.
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*/
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assert(interrupt_enable_counter < UINT32_MAX);
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if (interrupt_enable_counter > 0) {
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assert(primask & 0x1);
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}
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interrupt_enable_counter++;
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}
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void core_util_critical_section_exit()
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{
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/* If critical_section_enter has not previously been called, do nothing */
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if (interrupt_enable_counter) {
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uint32_t primask = __get_PRIMASK(); /* get the current interrupt enabled state */
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assert(primask & 0x1); /* Interrupts must be disabled on invoking an exit from a critical section */
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interrupt_enable_counter--;
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/* Only re-enable interrupts if we are exiting the last of the nested critical sections and
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interrupts were enabled on entry to the first critical section.
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*/
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if (!interrupt_enable_counter && !critical_primask) {
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__enable_irq();
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}
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}
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}
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#endif // defined(TARGET_LIKE_MBED) && !defined(TARGET_NORDIC)
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