89 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			89 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* The kernel call implemented in this file:
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 *   m_type:	SYS_VDEVIO
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 *
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 * The parameters for this kernel call are:
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 *    m2_i3:	DIO_REQUEST	(request input or output)	
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 *    m2_i1:	DIO_TYPE	(flag indicating byte, word, or long)
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 *    m2_p1:	DIO_VEC_ADDR	(pointer to port/ value pairs)	
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 *    m2_i2:	DIO_VEC_SIZE	(number of ports to read or write) 
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 */
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#include "../system.h"
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#include <minix/devio.h>
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#if USE_VDEVIO
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/* Buffer for SYS_VDEVIO to copy (port,value)-pairs from/ to user. */
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PRIVATE char vdevio_buf[VDEVIO_BUF_SIZE];      
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PRIVATE pvb_pair_t *pvb = (pvb_pair_t *) vdevio_buf;           
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PRIVATE pvw_pair_t *pvw = (pvw_pair_t *) vdevio_buf;      
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PRIVATE pvl_pair_t *pvl = (pvl_pair_t *) vdevio_buf;     
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/*===========================================================================*
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 *			        do_vdevio                                    *
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 *===========================================================================*/
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PUBLIC int do_vdevio(m_ptr)
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register message *m_ptr;	/* pointer to request message */
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{
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/* Perform a series of device I/O on behalf of a non-kernel process. The 
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 * I/O addresses and I/O values are fetched from and returned to some buffer
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 * in user space. The actual I/O is wrapped by lock() and unlock() to prevent
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 * that I/O batch from being interrrupted.
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 * This is the counterpart of do_devio, which performs a single device I/O. 
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 */ 
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  int vec_size;               /* size of vector */
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  int io_in;                  /* true if input */
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  size_t bytes;               /* # bytes to be copied */
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  int caller_proc;            /* process number of caller */
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  vir_bytes caller_vir;       /* virtual address at caller */
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  phys_bytes caller_phys;     /* physical address at caller */
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  int i;
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  /* Get the request, size of the request vector, and check the values. */
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  if (m_ptr->DIO_REQUEST == DIO_INPUT) io_in = TRUE;
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  else if (m_ptr->DIO_REQUEST == DIO_OUTPUT) io_in = FALSE;
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  else return(EINVAL);
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  if ((vec_size = m_ptr->DIO_VEC_SIZE) <= 0) return(EINVAL);
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  switch (m_ptr->DIO_TYPE) {
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      case DIO_BYTE: bytes = vec_size * sizeof(pvb_pair_t); break;
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      case DIO_WORD: bytes = vec_size * sizeof(pvw_pair_t); break;
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      case DIO_LONG: bytes = vec_size * sizeof(pvl_pair_t); break;
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      default:  return(EINVAL);   /* check type once and for all */
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  }
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  if (bytes > sizeof(vdevio_buf))  return(E2BIG);
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  /* Calculate physical addresses and copy (port,value)-pairs from user. */
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  caller_proc = m_ptr->m_source; 
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  caller_vir = (vir_bytes) m_ptr->DIO_VEC_ADDR;
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  caller_phys = umap_local(proc_addr(caller_proc), D, caller_vir, bytes);
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  if (0 == caller_phys) return(EFAULT);
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  phys_copy(caller_phys, vir2phys(vdevio_buf), (phys_bytes) bytes);
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  /* Perform actual device I/O for byte, word, and long values. Note that 
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   * the entire switch is wrapped in lock() and unlock() to prevent the I/O
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   * batch from being interrupted. 
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   */  
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  lock(13, "do_vdevio");
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  switch (m_ptr->DIO_TYPE) {
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  case DIO_BYTE: 					 /* byte values */
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      if (io_in) for (i=0; i<vec_size; i++)  pvb[i].value = inb(pvb[i].port); 
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      else       for (i=0; i<vec_size; i++)  outb(pvb[i].port, pvb[i].value); 
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      break; 
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  case DIO_WORD:					  /* word values */
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      if (io_in) for (i=0; i<vec_size; i++)  pvw[i].value = inw(pvw[i].port);  
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      else       for (i=0; i<vec_size; i++)  outw(pvw[i].port, pvw[i].value); 
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      break; 
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  default:            					  /* long values */
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      if (io_in) for (i=0; i<vec_size; i++) pvl[i].value = inl(pvl[i].port);  
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      else       for (i=0; i<vec_size; i++) outl(pvb[i].port, pvl[i].value); 
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  }
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  unlock(13);
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  /* Almost done, copy back results for input requests. */
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  if (io_in) phys_copy(vir2phys(vdevio_buf), caller_phys, (phys_bytes) bytes);
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  return(OK);
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}
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#endif /* USE_VDEVIO */
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