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