minix/kernel/system/do_vdevio.c
Tomas Hruby 728f0f0c49 Removal of the system task
* Userspace change to use the new kernel calls

	- _taskcall(SYSTASK...) changed to _kernel_call(...)

	- int 32 reused for the kernel calls

	- _do_kernel_call() to make the trap to kernel

	- kernel_call() to make the actuall kernel call from C using
	  _do_kernel_call()

	- unlike ipc call the kernel call always succeeds as kernel is
	  always available, however, kernel may return an error

* Kernel side implementation of kernel calls

	- the SYSTEm task does not run, only the proc table entry is
	  preserved

	- every data_copy(SYSTEM is no data_copy(KERNEL

	- "locking" is an empty operation now as everything runs in
	  kernel

	- sys_task() is replaced by kernel_call() which copies the
	  message into kernel, dispatches the call to its handler and
	  finishes by either copying the results back to userspace (if
	  need be) or by suspending the process because of VM

	- suspended processes are later made runnable once the memory
	  issue is resolved, picked up by the scheduler and only at
	  this time the call is resumed (in fact restarted) which does
	  not need to copy the message from userspace as the message
	  is already saved in the process structure.

	- no ned for the vmrestart queue, the scheduler will restart
	  the system calls

	- no special case in do_vmctl(), all requests remove the
	  RTS_VMREQUEST flag
2010-02-09 15:20:09 +00:00

171 lines
4.6 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 "../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)
{
kprintf(
"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. Note that
* the entire switch is wrapped in lock() and unlock() to prevent the I/O
* batch from being interrupted.
*/
lock;
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);
}
}
}
unlock;
/* 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:
minix_panic("do_vdevio: unaligned port", port);
return EPERM;
}
#endif /* USE_VDEVIO */