156 lines
4.8 KiB
C
156 lines
4.8 KiB
C
/* The kernel 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 kernel 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 (provides index to be returned on interrupt)
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* ,, ,, (returns index of irq hook assigned at kernel)
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*/
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#include "../system.h"
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#if USE_IRQCTL
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FORWARD _PROTOTYPE(int generic_handler, (irq_hook_t *hook));
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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 notify_id;
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int r = OK;
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int i;
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irq_hook_t *hook_ptr;
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struct proc *rp;
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struct priv *privp;
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/* Hook identifiers start at 1 and end at NR_IRQ_HOOKS. */
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irq_hook_id = (unsigned) m_ptr->IRQ_HOOK_ID - 1;
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irq_vec = (unsigned) m_ptr->IRQ_VECTOR;
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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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if (irq_hook_id >= NR_IRQ_HOOKS ||
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irq_hooks[irq_hook_id].proc_nr == NONE) 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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if (irq_vec < 0 || irq_vec >= NR_IRQ_VECTORS) return(EINVAL);
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rp= proc_addr(m_ptr->m_source);
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privp= priv(rp);
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if (!privp)
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{
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kprintf("no priv structure!\n");
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return EPERM;
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}
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if (privp->s_flags & CHECK_IRQ)
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{
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for (i= 0; i<privp->s_nr_irq; i++)
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{
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if (irq_vec == privp->s_irq_tab[i])
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break;
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}
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if (i >= privp->s_nr_irq)
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{
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kprintf(
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"do_irqctl: IRQ check failed for proc %d, IRQ %d\n",
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m_ptr->m_source, irq_vec);
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return EPERM;
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}
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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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/* When setting a policy, the caller must provide an identifier that
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* is returned on the notification message if a interrupt occurs.
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*/
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notify_id = (unsigned) m_ptr->IRQ_HOOK_ID;
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if (notify_id > CHAR_BIT * sizeof(irq_id_t) - 1) return(EINVAL);
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/* Install the handler. */
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hook_ptr->proc_nr = m_ptr->m_source; /* process to notify */
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hook_ptr->notify_id = notify_id; /* identifier to pass */
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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 + 1;
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break;
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case IRQ_RMPOLICY:
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if (irq_hook_id >= NR_IRQ_HOOKS ||
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irq_hooks[irq_hook_id].proc_nr == NONE) {
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return(EINVAL);
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} else if (m_ptr->m_source != irq_hooks[irq_hook_id].proc_nr) {
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return(EPERM);
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}
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/* Remove the handler and return. */
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rm_irq_handler(&irq_hooks[irq_hook_id]);
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break;
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default:
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r = EINVAL; /* invalid IRQ_REQUEST */
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}
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return(r);
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}
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/*===========================================================================*
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* generic_handler *
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*===========================================================================*/
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PRIVATE int generic_handler(hook)
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irq_hook_t *hook;
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{
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/* This function handles hardware interrupt in a simple and generic way. All
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* interrupts are transformed into messages to a driver. The IRQ line will be
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* reenabled if the policy says so.
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*/
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/* As a side-effect, the interrupt handler gathers random information by
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* timestamping the interrupt events. This is used for /dev/random.
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*/
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get_randomness(hook->irq);
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/* Add a bit for this interrupt to the process' pending interrupts. When
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* sending the notification message, this bit map will be magically set
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* as an argument.
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*/
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priv(proc_addr(hook->proc_nr))->s_int_pending |= (1 << hook->notify_id);
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/* Build notification message and return. */
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lock_notify(HARDWARE, hook->proc_nr);
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return(hook->policy & IRQ_REENABLE);
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}
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#endif /* USE_IRQCTL */
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