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

166 lines
4.5 KiB
C

/* The kernel call implemented in this file:
* m_type: SYS_VDEVIO
*
* The parameters for this kernel call are:
* m2_i3: DIO_REQUEST (request input or output)
* m2_p1: DIO_VEC_ADDR (pointer to port/ value pairs)
* m2_i2: DIO_VEC_SIZE (number of ports to read or write)
*/
#include "kernel/system.h"
#include <minix/devio.h>
#include <minix/endpoint.h>
#include <minix/portio.h>
#if USE_VDEVIO
/* Buffer for SYS_VDEVIO to copy (port,value)-pairs from/ to user. */
PRIVATE char vdevio_buf[VDEVIO_BUF_SIZE];
PRIVATE pvb_pair_t *pvb = (pvb_pair_t *) vdevio_buf;
PRIVATE pvw_pair_t *pvw = (pvw_pair_t *) vdevio_buf;
PRIVATE pvl_pair_t *pvl = (pvl_pair_t *) vdevio_buf;
/*===========================================================================*
* do_vdevio *
*===========================================================================*/
PUBLIC int do_vdevio(struct proc * caller, message * m_ptr)
{
/* Perform a series of device I/O on behalf of a non-kernel process. The
* I/O addresses and I/O values are fetched from and returned to some buffer
* in user space. The actual I/O is wrapped by lock() and unlock() to prevent
* that I/O batch from being interrrupted.
* This is the counterpart of do_devio, which performs a single device I/O.
*/
int vec_size; /* size of vector */
int io_in; /* true if input */
size_t bytes; /* # bytes to be copied */
port_t port;
int i, j, io_size, nr_io_range;
int io_dir, io_type;
struct priv *privp;
struct io_range *iorp;
int r;
/* Get the request, size of the request vector, and check the values. */
io_dir = m_ptr->DIO_REQUEST & _DIO_DIRMASK;
io_type = m_ptr->DIO_REQUEST & _DIO_TYPEMASK;
if (io_dir == _DIO_INPUT) io_in = TRUE;
else if (io_dir == _DIO_OUTPUT) io_in = FALSE;
else return(EINVAL);
if ((vec_size = m_ptr->DIO_VEC_SIZE) <= 0) return(EINVAL);
switch (io_type) {
case _DIO_BYTE:
bytes = vec_size * sizeof(pvb_pair_t);
io_size= sizeof(u8_t);
break;
case _DIO_WORD:
bytes = vec_size * sizeof(pvw_pair_t);
io_size= sizeof(u16_t);
break;
case _DIO_LONG:
bytes = vec_size * sizeof(pvl_pair_t);
io_size= sizeof(u32_t);
break;
default: return(EINVAL); /* check type once and for all */
}
if (bytes > sizeof(vdevio_buf)) return(E2BIG);
/* Copy (port,value)-pairs from user. */
if((r=data_copy(caller->p_endpoint, (vir_bytes) m_ptr->DIO_VEC_ADDR,
KERNEL, (vir_bytes) vdevio_buf, bytes)) != OK)
return r;
privp= priv(caller);
if (privp && (privp->s_flags & CHECK_IO_PORT))
{
/* Check whether the I/O is allowed */
nr_io_range= privp->s_nr_io_range;
for (i=0; i<vec_size; i++)
{
switch (io_type) {
case _DIO_BYTE: port= pvb[i].port; break;
case _DIO_WORD: port= pvw[i].port; break;
default: port= pvl[i].port; break;
}
for (j= 0, iorp= privp->s_io_tab; j<nr_io_range; j++, iorp++)
{
if (port >= iorp->ior_base &&
port+io_size-1 <= iorp->ior_limit)
{
break;
}
}
if (j >= nr_io_range)
{
printf(
"do_vdevio: I/O port check failed for proc %d, port 0x%x\n",
m_ptr->m_source, port);
return EPERM;
}
}
}
/* Perform actual device I/O for byte, word, and long values */
switch (io_type) {
case _DIO_BYTE: /* byte values */
if (io_in) for (i=0; i<vec_size; i++)
pvb[i].value = inb( pvb[i].port);
else for (i=0; i<vec_size; i++)
outb( pvb[i].port, pvb[i].value);
break;
case _DIO_WORD: /* word values */
if (io_in)
{
for (i=0; i<vec_size; i++)
{
port= pvw[i].port;
if (port & 1) goto bad;
pvw[i].value = inw( pvw[i].port);
}
}
else
{
for (i=0; i<vec_size; i++)
{
port= pvw[i].port;
if (port & 1) goto bad;
outw( pvw[i].port, pvw[i].value);
}
}
break;
default: /* long values */
if (io_in)
{
for (i=0; i<vec_size; i++)
{
port= pvl[i].port;
if (port & 3) goto bad;
pvl[i].value = inl(pvl[i].port);
}
}
else
{
for (i=0; i<vec_size; i++)
{
port= pvl[i].port;
if (port & 3) goto bad;
outl( pvb[i].port, pvl[i].value);
}
}
}
/* Almost done, copy back results for input requests. */
if (io_in)
if((r=data_copy(KERNEL, (vir_bytes) vdevio_buf,
caller->p_endpoint, (vir_bytes) m_ptr->DIO_VEC_ADDR,
(phys_bytes) bytes)) != OK)
return r;
return(OK);
bad:
panic("do_vdevio: unaligned port: %d", port);
return EPERM;
}
#endif /* USE_VDEVIO */