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/* Copyright (C) 2004 David Decotigny
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
USA.
*/
#include "idt.h"
#include "i8259.h"
#include "irq.h"
/** array of IRQ wrappers, defined in irq_wrappers.S */
extern sos_vaddr_t sos_irq_wrapper_array[SOS_IRQ_NUM];
/** arrays of IRQ handlers, shared with irq_wrappers.S */
sos_irq_handler_t sos_irq_handler_array[SOS_IRQ_NUM] = { NULL, };
/** Number of interrupt handlers that are currently executing */
sos_ui32_t sos_irq_nested_level_counter;
sos_ret_t sos_irq_subsystem_setup(void)
{
sos_irq_nested_level_counter = 0;
return sos_i8259_subsystem_setup();
}
sos_ret_t sos_irq_set_routine(int irq_level,
sos_irq_handler_t routine)
{
sos_ret_t retval;
sos_ui32_t flags;
if ((irq_level < 0) || (irq_level >= SOS_IRQ_NUM))
return -SOS_EINVAL;
sos_disable_IRQs(flags);
retval = SOS_OK;
/* Set the irq routine to be called by the IRQ wrapper */
sos_irq_handler_array[irq_level] = routine;
/* If the irq is to be enabled, update the IDT with the IRQ
wrapper */
if (routine != NULL)
{
retval
= sos_idt_set_handler(SOS_IRQ_BASE + irq_level,
(sos_vaddr_t) sos_irq_wrapper_array[irq_level],
0 /* CPL0 routine */);
/* A problem occured */
if (retval != SOS_OK)
sos_irq_handler_array[irq_level] = NULL;
}
else /* Disable this idt entry */
{
retval
= sos_idt_set_handler(SOS_IRQ_BASE + irq_level,
(sos_vaddr_t)NULL /* Disable IDTE */,
0 /* Don't care */);
}
/* Update the PIC only if an IRQ handler has been set */
if (sos_irq_handler_array[irq_level] != NULL)
sos_i8259_enable_irq_line(irq_level);
else
sos_i8259_disable_irq_line(irq_level);
sos_restore_IRQs(flags);
return retval;
}
sos_irq_handler_t sos_irq_get_routine(int irq_level)
{
if ((irq_level < 0) || (irq_level >= SOS_IRQ_NUM))
return NULL;
/* Expected to be atomic */
return sos_irq_handler_array[irq_level];
}
sos_ui32_t sos_irq_get_nested_level()
{
/* No need to disable interrupts here */
return sos_irq_nested_level_counter;
}
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