minix/kernel/system/do_devio.c
2010-04-01 22:22:33 +00:00

90 lines
2.4 KiB
C

/* The kernel call implemented in this file:
* m_type: SYS_DEVIO
*
* The parameters for this kernel call are:
* m2_i3: DIO_REQUEST (request input or output)
* m2_l1: DIO_PORT (port to read/ write)
* m2_l2: DIO_VALUE (value to write/ return value read)
*/
#include "kernel/system.h"
#include <minix/devio.h>
#include <minix/endpoint.h>
#include <minix/portio.h>
#if USE_DEVIO
/*===========================================================================*
* do_devio *
*===========================================================================*/
PUBLIC int do_devio(struct proc * caller, message * m_ptr)
{
struct priv *privp;
port_t port;
struct io_range *iorp;
int i, size, nr_io_range;
int io_type, io_dir;
io_type = m_ptr->DIO_REQUEST & _DIO_TYPEMASK;
io_dir = m_ptr->DIO_REQUEST & _DIO_DIRMASK;
switch (io_type)
{
case _DIO_BYTE: size= 1; break;
case _DIO_WORD: size= 2; break;
case _DIO_LONG: size= 4; break;
default: size= 4; break; /* Be conservative */
}
privp= priv(caller);
if (!privp)
{
printf("no priv structure!\n");
goto doit;
}
if (privp->s_flags & CHECK_IO_PORT)
{
port= m_ptr->DIO_PORT;
nr_io_range= privp->s_nr_io_range;
for (i= 0, iorp= privp->s_io_tab; i<nr_io_range; i++, iorp++)
{
if (port >= iorp->ior_base && port+size-1 <= iorp->ior_limit)
break;
}
if (i >= nr_io_range)
{
printf("do_devio: port 0x%x (size %d) not allowed\n",
m_ptr->DIO_PORT, size);
return EPERM;
}
}
doit:
if (m_ptr->DIO_PORT & (size-1))
{
printf("do_devio: unaligned port 0x%x (size %d)\n",
m_ptr->DIO_PORT, size);
return EPERM;
}
/* Process a single I/O request for byte, word, and long values. */
if (io_dir == _DIO_INPUT) {
switch (io_type) {
/* maybe "it" should not be called ports */
case _DIO_BYTE: m_ptr->DIO_VALUE = inb(m_ptr->DIO_PORT); break;
case _DIO_WORD: m_ptr->DIO_VALUE = inw(m_ptr->DIO_PORT); break;
case _DIO_LONG: m_ptr->DIO_VALUE = inl(m_ptr->DIO_PORT); break;
default: return(EINVAL);
}
} else {
switch (io_type) {
case _DIO_BYTE: outb(m_ptr->DIO_PORT, m_ptr->DIO_VALUE); break;
case _DIO_WORD: outw(m_ptr->DIO_PORT, m_ptr->DIO_VALUE); break;
case _DIO_LONG: outl(m_ptr->DIO_PORT, m_ptr->DIO_VALUE); break;
default: return(EINVAL);
}
}
return(OK);
}
#endif /* USE_DEVIO */