kernel/system/do_devio.c

   1 /* The kernel call implemented in this file:
   2  *   m_type:    SYS_DEVIO
   3  *
   4  * The parameters for this kernel call are:
   5  *   m2_i3:     DIO_REQUEST     (request input or output)
   6  *   m2_l1:     DIO_PORT        (port to read/ write)
   7  *   m2_l2:     DIO_VALUE       (value to write/ return value read)
   8  */
   9
  10 #include "../system.h"
  11 #include <minix/devio.h>
  12 #include <minix/endpoint.h>
  13 #include <minix/portio.h>
  14
  15 #if USE_DEVIO
  16
  17 /*===========================================================================*
  18  *                              do_devio                                     *
  19  *===========================================================================*/
  20 PUBLIC int do_devio(m_ptr)
  21 register message *m_ptr;        /* pointer to request message */
  22 {
  23     struct proc *rp;
  24     struct priv *privp;
  25     port_t port;
  26     struct io_range *iorp;
  27     int i, size, nr_io_range;
  28     int io_type, io_dir;
  29
  30     io_type = m_ptr->DIO_REQUEST & _DIO_TYPEMASK;
  31     io_dir  = m_ptr->DIO_REQUEST & _DIO_DIRMASK;
  32
  33         switch (io_type)
  34         {
  35         case _DIO_BYTE: size= 1; break;
  36         case _DIO_WORD: size= 2; break;
  37         case _DIO_LONG: size= 4; break;
  38         default: size= 4; break;        /* Be conservative */
  39         }
  40
  41     rp= proc_addr(who_p);
  42     privp= priv(rp);
  43     if (!privp)
  44     {
  45         kprintf("no priv structure!\n");
  46         goto doit;
  47     }
  48     if (privp->s_flags & CHECK_IO_PORT)
  49     {
  50         switch (io_type)
  51         {
  52         case _DIO_BYTE: size= 1; break;
  53         case _DIO_WORD: size= 2; break;
  54         case _DIO_LONG: size= 4; break;
  55         default: size= 4; break;        /* Be conservative */
  56         }
  57         port= m_ptr->DIO_PORT;
  58         nr_io_range= privp->s_nr_io_range;
  59         for (i= 0, iorp= privp->s_io_tab; i<nr_io_range; i++, iorp++)
  60         {
  61                 if (port >= iorp->ior_base && port+size-1 <= iorp->ior_limit)
  62                         break;
  63         }
  64         if (i >= nr_io_range)
  65         {
  66                 static int curr= 0, limit= 100, extra= 20;
  67
  68                 if (curr < limit+extra)
  69                 {
  70                         kprintf("do_devio: port 0x%x (size %d) not allowed\n",
  71                                 m_ptr->DIO_PORT, size);
  72                 } else if (curr == limit+extra)
  73                 {
  74                         kprintf("do_devio: no debug output for a while\n");
  75                 }
  76                 else if (curr == 2*limit-1)
  77                         limit *= 2;
  78                 curr++;
  79                 return EPERM;
  80         }
  81     }
  82
  83 doit:
  84     if (m_ptr->DIO_PORT & (size-1))
  85     {
  86         static int curr= 0, limit= 100, extra= 20;
  87
  88         if (curr < limit+extra)
  89         {
  90                 kprintf("do_devio: unaligned port 0x%x (size %d)\n",
  91                         m_ptr->DIO_PORT, size);
  92         } else if (curr == limit+extra)
  93         {
  94                 kprintf("do_devio: no debug output for a while\n");
  95         }
  96         else if (curr == 2*limit-1)
  97                 limit *= 2;
  98         curr++;
  99         return EPERM;
 100     }
 101
 102 /* Process a single I/O request for byte, word, and long values. */
 103     if (io_dir == _DIO_INPUT) {
 104       switch (io_type) {
 105         /* maybe "it" should not be called ports */
 106         case _DIO_BYTE: m_ptr->DIO_VALUE = inb(m_ptr->DIO_PORT); break;
 107         case _DIO_WORD: m_ptr->DIO_VALUE = inw(m_ptr->DIO_PORT); break;
 108         case _DIO_LONG: m_ptr->DIO_VALUE = inl(m_ptr->DIO_PORT); break;
 109         default: return(EINVAL);
 110       }
 111     } else {
 112       switch (io_type) {
 113         case _DIO_BYTE: outb(m_ptr->DIO_PORT, m_ptr->DIO_VALUE); break;
 114         case _DIO_WORD: outw(m_ptr->DIO_PORT, m_ptr->DIO_VALUE); break;
 115         case _DIO_LONG: outl(m_ptr->DIO_PORT, m_ptr->DIO_VALUE); break;
 116         default: return(EINVAL);
 117       }
 118     }
 119     return(OK);
 120 }
 121
 122 #endif /* USE_DEVIO */