zephyr/arch/arm/include/CortexM/exc.h

124 lines
3.6 KiB
C

/* exc.h - exception/interrupt context helpers for Cortex-M CPUs */
/*
* Copyright (c) 2013-2014 Wind River Systems, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1) Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2) Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3) Neither the name of Wind River Systems nor the names of its contributors
* may be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
DESCRIPTION
Exception/interrupt context helpers.
*/
#ifndef _ARM_CORTEXM_ISR__H_
#define _ARM_CORTEXM_ISR__H_
#include <nanokernel/cpu.h>
#ifdef _ASMLANGUAGE
/* nothing */
#else
/*******************************************************************************
*
* _IpsrGet - obtain value of IPSR register
*
* Obtain and return current value of IPSR register.
*
* RETURNS: the contents of the IPSR register
*
* \NOMANUAL
*/
#if defined(__GNUC__)
static ALWAYS_INLINE uint32_t _IpsrGet(void)
{
uint32_t vector;
__asm__ volatile("mrs %0, IPSR\n\t" : "=r"(vector));
return vector;
}
#elif defined(__DCC__)
__asm volatile uint32_t _IpsrGet(void)
{
% !"r0" mrs r0, IPSR
}
#endif
/*******************************************************************************
*
* _IsInIsr - find out if running in an ISR context
*
* The current executing vector is found in the IPSR register. We consider the
* IRQs (exception 16 and up), and the PendSV and SYSTICK exceptions, to be
* interrupts. Taking a fault within an exception is also considered in
* interrupt context.
*
* RETURNS: 1 if in ISR, 0 if not.
*
* \NOMANUAL
*/
static ALWAYS_INLINE int _IsInIsr(void)
{
uint32_t vector = _IpsrGet();
/* IRQs + PendSV + SYSTICK are interrupts */
return (vector > 13) || (vector && _ScbIsNestedExc());
}
/*******************************************************************************
* _ExcSetup - setup system exceptions
*
* Set exception priorities to conform with the BASEPRI locking mechanism.
* Set PendSV priority to lowest possible.
*
* Enable fault exceptions.
*
* RETURNS: N/A
*
* \NOMANUAL
*/
static ALWAYS_INLINE void _ExcSetup(void)
{
_ScbExcPrioSet(_EXC_PENDSV, _EXC_PRIO(0xff));
_ScbExcPrioSet(_EXC_SVC, _EXC_PRIO(0x01));
_ScbExcPrioSet(_EXC_MPU_FAULT, _EXC_PRIO(0x01));
_ScbExcPrioSet(_EXC_BUS_FAULT, _EXC_PRIO(0x01));
_ScbExcPrioSet(_EXC_USAGE_FAULT, _EXC_PRIO(0x01));
_ScbUsageFaultEnable();
_ScbBusFaultEnable();
_ScbMemFaultEnable();
}
#endif /* _ASMLANGUAGE */
#endif /* _ARM_CORTEXM_ISR__H_ */