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

162 lines
4.4 KiB
C

/*
* Copyright (c) 2013-2014 Wind River Systems, Inc.
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
* @brief Exception/interrupt context helpers for Cortex-M CPUs
*
* Exception/interrupt context helpers.
*/
#ifndef ZEPHYR_ARCH_ARM_INCLUDE_CORTEX_M_EXC_H_
#define ZEPHYR_ARCH_ARM_INCLUDE_CORTEX_M_EXC_H_
#include <arch/cpu.h>
#ifdef _ASMLANGUAGE
/* nothing */
#else
#include <arch/arm/cortex_m/cmsis.h>
#include <arch/arm/exc.h>
#include <irq_offload.h>
#ifdef __cplusplus
extern "C" {
#endif
#ifdef CONFIG_IRQ_OFFLOAD
extern volatile irq_offload_routine_t offload_routine;
#endif
/* Writes to the AIRCR must be accompanied by a write of the value 0x05FA
* to the Vector Key field, otherwise the writes are ignored.
*/
#define AIRCR_VECT_KEY_PERMIT_WRITE 0x05FAUL
/*
* The current executing vector is found in the IPSR register. All
* IRQs and system exceptions are considered as interrupt context.
*/
static ALWAYS_INLINE bool z_arch_is_in_isr(void)
{
return (__get_IPSR()) ? (true) : (false);
}
/**
* @brief Find out if we were in ISR context
* before the current exception occurred.
*
* A function that determines, based on inspecting the current
* ESF, whether the processor was in handler mode before entering
* the current exception state (i.e. nested exception) or not.
*
* Notes:
* - The function shall only be called from ISR context.
* - We do not use ARM processor state flags to determine
* whether we are in a nested exception; we rely on the
* RETPSR value stacked on the ESF. Hence, the function
* assumes that the ESF stack frame has a valid RETPSR
* value.
*
* @param esf the exception stack frame (cannot be NULL)
* @return true if execution state was in handler mode, before
* the current exception occurred, otherwise false.
*/
static ALWAYS_INLINE bool z_arch_is_in_nested_exception(
const z_arch_esf_t *esf)
{
return (esf->basic.xpsr & IPSR_ISR_Msk) ? (true) : (false);
}
/**
* @brief Setup system exceptions
*
* Set exception priorities to conform with the BASEPRI locking mechanism.
* Set PendSV priority to lowest possible.
*
* Enable fault exceptions.
*
* @return N/A
*/
static ALWAYS_INLINE void z_arm_exc_setup(void)
{
NVIC_SetPriority(PendSV_IRQn, 0xff);
#ifdef CONFIG_CPU_CORTEX_M_HAS_BASEPRI
NVIC_SetPriority(SVCall_IRQn, _EXC_SVC_PRIO);
#endif
#ifdef CONFIG_CPU_CORTEX_M_HAS_PROGRAMMABLE_FAULT_PRIOS
NVIC_SetPriority(MemoryManagement_IRQn, _EXC_FAULT_PRIO);
NVIC_SetPriority(BusFault_IRQn, _EXC_FAULT_PRIO);
NVIC_SetPriority(UsageFault_IRQn, _EXC_FAULT_PRIO);
#if defined(CONFIG_ARM_SECURE_FIRMWARE)
NVIC_SetPriority(SecureFault_IRQn, _EXC_FAULT_PRIO);
#endif /* CONFIG_ARM_SECURE_FIRMWARE */
/* Enable Usage, Mem, & Bus Faults */
SCB->SHCSR |= SCB_SHCSR_USGFAULTENA_Msk | SCB_SHCSR_MEMFAULTENA_Msk |
SCB_SHCSR_BUSFAULTENA_Msk;
#if defined(CONFIG_ARM_SECURE_FIRMWARE)
/* Enable Secure Fault */
SCB->SHCSR |= SCB_SHCSR_SECUREFAULTENA_Msk;
/* Clear BFAR before setting BusFaults to target Non-Secure state. */
SCB->BFAR = 0;
#endif /* CONFIG_ARM_SECURE_FIRMWARE */
#endif /* CONFIG_CPU_CORTEX_M_HAS_PROGRAMMABLE_FAULT_PRIOS */
#if defined(CONFIG_ARM_SECURE_FIRMWARE) && \
!defined(CONFIG_ARM_SECURE_BUSFAULT_HARDFAULT_NMI)
/* Set NMI, Hard, and Bus Faults as Non-Secure.
* NMI and Bus Faults targeting the Secure state will
* escalate to a SecureFault or SecureHardFault.
*/
SCB->AIRCR =
(SCB->AIRCR & (~(SCB_AIRCR_VECTKEY_Msk)))
| SCB_AIRCR_BFHFNMINS_Msk
| ((AIRCR_VECT_KEY_PERMIT_WRITE << SCB_AIRCR_VECTKEY_Pos) &
SCB_AIRCR_VECTKEY_Msk);
/* Note: Fault conditions that would generate a SecureFault
* in a PE with the Main Extension instead generate a
* SecureHardFault in a PE without the Main Extension.
*/
#endif /* ARM_SECURE_FIRMWARE && !ARM_SECURE_BUSFAULT_HARDFAULT_NMI */
}
/**
* @brief Clear Fault exceptions
*
* Clear out exceptions for Mem, Bus, Usage and Hard Faults
*
* @return N/A
*/
static ALWAYS_INLINE void z_arm_clear_faults(void)
{
#if defined(CONFIG_ARMV6_M_ARMV8_M_BASELINE)
#elif defined(CONFIG_ARMV7_M_ARMV8_M_MAINLINE)
/* Reset all faults */
SCB->CFSR = SCB_CFSR_USGFAULTSR_Msk |
SCB_CFSR_MEMFAULTSR_Msk |
SCB_CFSR_BUSFAULTSR_Msk;
/* Clear all Hard Faults - HFSR is write-one-to-clear */
SCB->HFSR = 0xffffffff;
#else
#error Unknown ARM architecture
#endif /* CONFIG_ARMV6_M_ARMV8_M_BASELINE */
}
#ifdef __cplusplus
}
#endif
#endif /* _ASMLANGUAGE */
#endif /* ZEPHYR_ARCH_ARM_INCLUDE_CORTEX_M_EXC_H_ */