98 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			98 lines
		
	
	
		
			3.0 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 r = OK;
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  irq_hook_t *hook_ptr;
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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) {
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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 + 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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  		r = EINVAL;
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  	} else {
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	 	if (m_ptr->m_source != irq_hooks[irq_hook_id].proc_nr) {
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	  		r = EPERM;
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	  	} else {
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	        	r = rm_irq_handler(irq_vec, irq_hooks[irq_hook_id].id);
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	        }
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        }
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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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