minix/kernel/system/do_vdevio.c

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/* The system call implemented in this file:
* m_type: SYS_VDEVIO
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*
* The parameters for this system call are:
* m2_i3: DIO_REQUEST (request input or output)
* m2_i1: DIO_TYPE (flag indicating byte, word, or long)
* m2_p1: DIO_VEC_ADDR (pointer to port/ value pairs)
* m2_i2: DIO_VEC_SIZE (number of ports to read or write)
*
* Changes:
* Apr 18, 2004 created to support user-space drivers (Jorrit N. Herder)
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*/
#include "../system.h"
#include <minix/devio.h>
#if USE_VDEVIO
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/* 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;
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/*===========================================================================*
* do_vdevio *
*===========================================================================*/
PUBLIC int do_vdevio(m_ptr)
register message *m_ptr; /* pointer to request message */
{
/* 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 */
int caller_proc; /* process number of caller */
vir_bytes caller_vir; /* virtual address at caller */
phys_bytes caller_phys; /* physical address at caller */
int i;
/* Get the request, size of the request vector, and check the values. */
if (m_ptr->DIO_REQUEST == DIO_INPUT) io_in = TRUE;
else if (m_ptr->DIO_REQUEST == DIO_OUTPUT) io_in = FALSE;
else return(EINVAL);
if ((vec_size = m_ptr->DIO_VEC_SIZE) <= 0) return(EINVAL);
switch (m_ptr->DIO_TYPE) {
case DIO_BYTE: bytes = vec_size * sizeof(pvb_pair_t); break;
case DIO_WORD: bytes = vec_size * sizeof(pvw_pair_t); break;
case DIO_LONG: bytes = vec_size * sizeof(pvl_pair_t); break;
default: return(EINVAL); /* check type once and for all */
}
if (bytes > sizeof(vdevio_buf)) return(E2BIG);
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/* Calculate physical addresses and copy (port,value)-pairs from user. */
caller_proc = m_ptr->m_source;
caller_vir = (vir_bytes) m_ptr->DIO_VEC_ADDR;
caller_phys = umap_local(proc_addr(caller_proc), D, caller_vir, bytes);
if (0 == caller_phys) return(EFAULT);
phys_copy(caller_phys, vir2phys(vdevio_buf), (phys_bytes) bytes);
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/* 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(13, "do_vdevio");
switch (m_ptr->DIO_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++) pvw[i].value = inw(pvw[i].port);
else for (i=0; i<vec_size; i++) outw(pvw[i].port, pvw[i].value);
break;
default: /* long values */
if (io_in) for (i=0; i<vec_size; i++) pvl[i].value = inl(pvl[i].port);
else for (i=0; i<vec_size; i++) outl(pvb[i].port, pvl[i].value);
}
unlock(13);
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/* Almost done, copy back results for input requests. */
if (io_in) phys_copy(vir2phys(vdevio_buf), caller_phys, (phys_bytes) bytes);
return(OK);
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}
#endif /* USE_VDEVIO */
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