zephyr/arch/arm/core/irq_manage.c

140 lines
3.4 KiB
C

/*
* Copyright (c) 2013-2014 Wind River Systems, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @file
* @brief ARM CORTEX-M3 interrupt management
*
*
* Interrupt management: enabling/disabling and dynamic ISR
* connecting/replacing. SW_ISR_TABLE_DYNAMIC has to be enabled for
* connecting ISRs at runtime.
*/
#include <nanokernel.h>
#include <arch/cpu.h>
#include <misc/__assert.h>
#include <toolchain.h>
#include <sections.h>
#include <sw_isr_table.h>
#include <irq.h>
extern void __reserved(void);
/**
*
* @brief Enable an interrupt line
*
* Enable the interrupt. After this call, the CPU will receive interrupts for
* the specified <irq>.
*
* @return N/A
*/
void _arch_irq_enable(unsigned int irq)
{
_NvicIrqEnable(irq);
}
/**
*
* @brief Disable an interrupt line
*
* Disable an interrupt line. After this call, the CPU will stop receiving
* interrupts for the specified <irq>.
*
* @return N/A
*/
void _arch_irq_disable(unsigned int irq)
{
_NvicIrqDisable(irq);
}
/**
* @brief Return IRQ enable state
*
* @param irq IRQ line
* @return interrupt enable state, true or false
*/
int _arch_irq_is_enabled(unsigned int irq)
{
return _NvicIsIrqEnabled(irq);
}
/**
* @internal
*
* @brief Set an interrupt's priority
*
* The priority is verified if ASSERT_ON is enabled. The maximum number
* of priority levels is a little complex, as there are some hardware
* priority levels which are reserved: three for various types of exceptions,
* and possibly one additional to support zero latency interrupts.
*
* @return N/A
*/
void _irq_priority_set(unsigned int irq, unsigned int prio, uint32_t flags)
{
/* Hardware priority levels 0 and 1 reserved for Kernel use.
* So we add 2 to the requested priority level. If we support
* ZLI, 2 is also reserved so we add 3.
*/
#if CONFIG_ZERO_LATENCY_IRQS
/* If we have zero latency interrupts, that makes priority level 2
* a case with special semantics; it is not masked by irq_lock().
* Our policy is to express priority levels with special properties
* via flags
*/
if (flags & IRQ_ZERO_LATENCY) {
prio = 2;
} else {
prio += _IRQ_PRIO_OFFSET;
}
#else
ARG_UNUSED(flags);
prio += _IRQ_PRIO_OFFSET;
#endif
/* The last priority level is also used by PendSV exception, but
* allow other interrupts to use the same level, even if it ends up
* affecting performance (can still be useful on systems with a
* reduced set of priorities, like Cortex-M0/M0+).
*/
__ASSERT(prio <= ((1 << CONFIG_NUM_IRQ_PRIO_BITS) - 1),
"invalid priority %d! values must be less than %d\n",
prio - _IRQ_PRIO_OFFSET,
(1 << CONFIG_NUM_IRQ_PRIO_BITS) - (_IRQ_PRIO_OFFSET));
_NvicIrqPrioSet(irq, _EXC_PRIO(prio));
}
/**
*
* @brief Spurious interrupt handler
*
* Installed in all dynamic interrupt slots at boot time. Throws an error if
* called.
*
* See __reserved().
*
* @return N/A
*/
void _irq_spurious(void *unused)
{
ARG_UNUSED(unused);
__reserved();
}