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/*
* Copyright (c) 2007 Petr Stepan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - 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.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
/** @addtogroup arm32
* @{
*/
/** @file
* @brief Interrupts controlling routines.
*/
#include <arch/asm.h>
#include <arch/regutils.h>
#include <arch/machine.h>
#include <ddi/irq.h>
#include <ddi/device.h>
#include <interrupt.h>
/** Initial size of a table holding interrupt handlers. */
#define IRQ_COUNT 8
/** Disable interrupts.
*
* @return Old interrupt priority level.
*/
ipl_t interrupts_disable(void)
{
ipl_t ipl = current_status_reg_read();
current_status_reg_control_write(STATUS_REG_IRQ_DISABLED_BIT | ipl);
return ipl;
}
/** Enable interrupts.
*
* @return Old interrupt priority level.
*/
ipl_t interrupts_enable(void)
{
ipl_t ipl = current_status_reg_read();
/*
* Current implementation of interrupt handling is non-nested mode.
* So we don't enable interrupt if servicing IRQ.
* ToDo: Re-implement interrupt handling to handle nested interrupts.
*/
if ((ipl & 0x1f) != UNDEFINED_MODE)
current_status_reg_control_write(ipl & ~STATUS_REG_IRQ_DISABLED_BIT);
return ipl;
}
/** Restore interrupt priority level.
*
* @param ipl Saved interrupt priority level.
*/
void interrupts_restore(ipl_t ipl)
{
current_status_reg_control_write(
(current_status_reg_read() & ~STATUS_REG_IRQ_DISABLED_BIT) |
(ipl & STATUS_REG_IRQ_DISABLED_BIT));
}
/** Read interrupt priority level.
*
* @return Current interrupt priority level.
*/
ipl_t interrupts_read(void)
{
return current_status_reg_read();
}
/** Initialize basic tables for exception dispatching
* and starts the timer.
*/
void interrupt_init(void)
{
irq_init(IRQ_COUNT, IRQ_COUNT);
machine_timer_irq_start();
}
/** @}
*/