minix/kernel/system/irqctl.c
2005-05-02 14:30:04 +00:00

82 lines
2.6 KiB
C

/* The system call implemented in this file:
* m_type: SYS_IRQCTL
*
* The parameters for this system call are:
* m5_c1: IRQ_REQUEST (control operation to perform)
* m5_c2: IRQ_VECTOR (irq line that must be controlled)
* m5_i1: IRQ_POLICY (irq policy allows reenabling interrupts)
* m5_l3: IRQ_HOOK_ID (index of irq hook assigned at kernel)
*
* Author:
* Jorrit N. Herder <jnherder@cs.vu.nl>
*/
#include "../kernel.h"
#include "../system.h"
/*===========================================================================*
* do_irqctl *
*===========================================================================*/
PUBLIC int do_irqctl(m_ptr)
register message *m_ptr; /* pointer to request message */
{
/* Dismember the request message. */
int irq_vec;
int irq_hook_id;
int proc_nr;
irq_hook_t *hook_ptr;
/* See what is requested and take needed actions. */
switch(m_ptr->IRQ_REQUEST) {
/* Enable or disable IRQs. This is straightforward. */
case IRQ_ENABLE: {
irq_hook_id = (unsigned) m_ptr->IRQ_HOOK_ID;
if (irq_hook_id >= NR_IRQ_HOOKS) return(EINVAL);
enable_irq(&irq_hooks[irq_hook_id]);
break;
}
case IRQ_DISABLE: {
irq_hook_id = (unsigned) m_ptr->IRQ_HOOK_ID;
if (irq_hook_id >= NR_IRQ_HOOKS) return(EINVAL);
disable_irq(&irq_hooks[irq_hook_id]);
break;
}
/* Control IRQ policies. Set a policy and needed details in the IRQ table.
* This policy is used by a generic function to handle hardware interrupts.
*/
case IRQ_SETPOLICY: {
/* Check if IRQ line is acceptable. */
irq_vec = (unsigned) m_ptr->IRQ_VECTOR;
if ((unsigned) irq_vec >= NR_IRQ_VECTORS) {
kprintf("ST: irq line %d is not acceptable!\n", irq_vec);
return(EINVAL);
}
/* Find a free IRQ hook for this mapping. */
hook_ptr = NULL;
for (irq_hook_id=0; irq_hook_id<NR_IRQ_HOOKS; irq_hook_id++) {
if (irq_hooks[irq_hook_id].proc_nr == NONE) {
hook_ptr = &irq_hooks[irq_hook_id]; /* free hook */
break;
}
}
if (hook_ptr == NULL) return(ENOSPC);
/* Only caller can request IRQ mappings. Install handler. */
hook_ptr->proc_nr = m_ptr->m_source; /* process to notify */
hook_ptr->policy = m_ptr->IRQ_POLICY; /* policy for interrupts */
put_irq_handler(hook_ptr, irq_vec, generic_handler);
/* Return index of the IRQ hook in use. */
m_ptr->IRQ_HOOK_ID = irq_hook_id;
break;
}
default:
return(EINVAL); /* invalid IRQ_REQUEST */
}
return(OK);
}