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