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minix/drivers/libdriver/driver.c
Ben Gras e929676268 . made libdriver understand *_S variants 
. ioctl, transfer and 'other' functions get an extra parameter: 'safe', int
  is nonzero if function is called with *_S variant ('other' if ioctl)
2006-06-20 08:49:51 +00:00

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/* This file contains device independent device driver interface.
*
* Changes:
* Jul 25, 2005 added SYS_SIG type for signals (Jorrit N. Herder)
* Sep 15, 2004 added SYN_ALARM type for timeouts (Jorrit N. Herder)
* Jul 23, 2004 removed kernel dependencies (Jorrit N. Herder)
* Apr 02, 1992 constructed from AT wini and floppy driver (Kees J. Bot)
*
*
* The drivers support the following operations (using message format m2):
*
* m_type DEVICE IO_ENDPT COUNT POSITION ADRRESS
* ----------------------------------------------------------------
* | DEV_OPEN | device | proc nr | | | |
* |------------+---------+---------+---------+---------+---------|
* | DEV_CLOSE | device | proc nr | | | |
* |------------+---------+---------+---------+---------+---------|
* | DEV_READ | device | proc nr | bytes | offset | buf ptr |
* |------------+---------+---------+---------+---------+---------|
* | DEV_WRITE | device | proc nr | bytes | offset | buf ptr |
* |------------+---------+---------+---------+---------+---------|
* | DEV_GATHER | device | proc nr | iov len | offset | iov ptr |
* |------------+---------+---------+---------+---------+---------|
* | DEV_SCATTER| device | proc nr | iov len | offset | iov ptr |
* |------------+---------+---------+---------+---------+---------|
* | DEV_IOCTL | device | proc nr |func code| | buf ptr |
* |------------+---------+---------+---------+---------+---------|
* | CANCEL | device | proc nr | r/w | | |
* |------------+---------+---------+---------+---------+---------|
* | HARD_STOP | | | | | |
* |------------+---------+---------+---------+---------+---------|
* | DEV_*_S | variants using safecopies of above |
* ----------------------------------------------------------------
*
* The file contains one entry point:
*
* driver_task: called by the device dependent task entry
*/
#include "../drivers.h"
#include <sys/ioc_disk.h>
#include "driver.h"
#if (CHIP == INTEL)
#if USE_EXTRA_DMA_BUF && DMA_BUF_SIZE < 2048
/* A bit extra scratch for the Adaptec driver. */
#define BUF_EXTRA (2048 - DMA_BUF_SIZE)
#else
#define BUF_EXTRA 0
#endif
/* Claim space for variables. */
PRIVATE u8_t buffer[(unsigned) 2 * DMA_BUF_SIZE + BUF_EXTRA];
u8_t *tmp_buf; /* the DMA buffer eventually */
phys_bytes tmp_phys; /* phys address of DMA buffer */
#else /* CHIP != INTEL */
/* Claim space for variables. */
u8_t tmp_buf[DMA_BUF_SIZE]; /* the DMA buffer */
phys_bytes tmp_phys; /* phys address of DMA buffer */
#endif /* CHIP != INTEL */
FORWARD _PROTOTYPE( void init_buffer, (void) );
FORWARD _PROTOTYPE( int do_rdwt, (struct driver *dr, message *mp, int safe) );
FORWARD _PROTOTYPE( int do_vrdwt, (struct driver *dr, message *mp, int safe) );
int device_caller;
/*===========================================================================*
* driver_task *
*===========================================================================*/
PUBLIC void driver_task(dp)
struct driver *dp; /* Device dependent entry points. */
{
/* Main program of any device driver task. */
int r, proc_nr;
message mess;
/* Get a DMA buffer. */
init_buffer();
/* Here is the main loop of the disk task. It waits for a message, carries
* it out, and sends a reply.
*/
while (TRUE) {
/* Wait for a request to read or write a disk block. */
if (receive(ANY, &mess) != OK) continue;
device_caller = mess.m_source;
proc_nr = mess.IO_ENDPT;
/* Now carry out the work. */
switch(mess.m_type) {
case DEV_OPEN: r = (*dp->dr_open)(dp, &mess); break;
case DEV_CLOSE: r = (*dp->dr_close)(dp, &mess); break;
case DEV_IOCTL: r = (*dp->dr_ioctl)(dp, &mess, 0); break;
case DEV_IOCTL_S: r = (*dp->dr_ioctl)(dp, &mess, 1); break;
case CANCEL: r = (*dp->dr_cancel)(dp, &mess);break;
case DEV_SELECT: r = (*dp->dr_select)(dp, &mess);break;
case DEV_READ:
case DEV_WRITE: r = do_rdwt(dp, &mess, 0); break;
case DEV_READ_S:
case DEV_WRITE_S: r = do_rdwt(dp, &mess, 1); break;
case DEV_GATHER:
case DEV_SCATTER: r = do_vrdwt(dp, &mess, 0); break;
case DEV_GATHER_S:
case DEV_SCATTER_S: r = do_vrdwt(dp, &mess, 1); break;
case HARD_INT: /* leftover interrupt or expired timer. */
if(dp->dr_hw_int) {
(*dp->dr_hw_int)(dp, &mess);
}
continue;
case PROC_EVENT:
case SYS_SIG: (*dp->dr_signal)(dp, &mess);
continue; /* don't reply */
case SYN_ALARM: (*dp->dr_alarm)(dp, &mess);
continue; /* don't reply */
case DEV_PING: notify(mess.m_source);
continue;
default:
if(dp->dr_other)
r = (*dp->dr_other)(dp, &mess, 0);
else
r = EINVAL;
break;
}
/* Clean up leftover state. */
(*dp->dr_cleanup)();
/* Finally, prepare and send the reply message. */
if (r != EDONTREPLY) {
mess.m_type = TASK_REPLY;
mess.REP_ENDPT = proc_nr;
/* Status is # of bytes transferred or error code. */
mess.REP_STATUS = r;
send(device_caller, &mess);
}
}
}
/*===========================================================================*
* init_buffer *
*===========================================================================*/
PRIVATE void init_buffer()
{
/* Select a buffer that can safely be used for DMA transfers. It may also
* be used to read partition tables and such. Its absolute address is
* 'tmp_phys', the normal address is 'tmp_buf'.
*/
#if (CHIP == INTEL)
unsigned left;
tmp_buf = buffer;
sys_umap(SELF, D, (vir_bytes)buffer, (phys_bytes)sizeof(buffer), &tmp_phys);
if ((left = dma_bytes_left(tmp_phys)) < DMA_BUF_SIZE) {
/* First half of buffer crosses a 64K boundary, can't DMA into that */
tmp_buf += left;
tmp_phys += left;
}
#endif /* CHIP == INTEL */
}
/*===========================================================================*
* do_rdwt *
*===========================================================================*/
PRIVATE int do_rdwt(dp, mp, safe)
struct driver *dp; /* device dependent entry points */
message *mp; /* pointer to read or write message */
int safe; /* use safecopies? */
{
/* Carry out a single read or write request. */
iovec_t iovec1;
int r, opcode;
phys_bytes phys_addr;
/* Disk address? Address and length of the user buffer? */
if (mp->COUNT < 0) return(EINVAL);
/* Check the user buffer (not relevant for safe copies). */
if(!safe) {
sys_umap(mp->IO_ENDPT, D, (vir_bytes) mp->ADDRESS, mp->COUNT, &phys_addr);
if (phys_addr == 0) return(EFAULT);
}
/* Prepare for I/O. */
if ((*dp->dr_prepare)(mp->DEVICE) == NIL_DEV) return(ENXIO);
/* Create a one element scatter/gather vector for the buffer. */
if(mp->m_type == DEV_READ || mp->m_type == DEV_READ_S) opcode = DEV_GATHER;
else opcode = DEV_SCATTER;
iovec1.iov_addr = (vir_bytes) mp->ADDRESS;
iovec1.iov_size = mp->COUNT;
/* Transfer bytes from/to the device. */
r = (*dp->dr_transfer)(mp->IO_ENDPT, opcode, mp->POSITION, &iovec1, 1, safe);
/* Return the number of bytes transferred or an error code. */
return(r == OK ? (mp->COUNT - iovec1.iov_size) : r);
}
/*==========================================================================*
* do_vrdwt *
*==========================================================================*/
PRIVATE int do_vrdwt(dp, mp, safe)
struct driver *dp; /* device dependent entry points */
message *mp; /* pointer to read or write message */
int safe; /* use safecopies? */
{
/* Carry out an device read or write to/from a vector of user addresses.
* The "user addresses" are assumed to be safe, i.e. FS transferring to/from
* its own buffers, so they are not checked.
*/
static iovec_t iovec[NR_IOREQS];
iovec_t *iov;
phys_bytes iovec_size;
unsigned nr_req;
int r, j, opcode;
nr_req = mp->COUNT; /* Length of I/O vector */
{
/* Copy the vector from the caller to kernel space. */
if (nr_req > NR_IOREQS) nr_req = NR_IOREQS;
iovec_size = (phys_bytes) (nr_req * sizeof(iovec[0]));
if(safe) {
if (OK != sys_safecopyfrom(mp->m_source, (vir_bytes) mp->IO_GRANT,
0, (vir_bytes) iovec, iovec_size, D)) {
panic((*dp->dr_name)(),"bad (safe) I/O vector by", mp->m_source);
}
} else {
if (OK != sys_datacopy(mp->m_source, (vir_bytes) mp->ADDRESS,
SELF, (vir_bytes) iovec, iovec_size)) {
panic((*dp->dr_name)(),"bad I/O vector by", mp->m_source);
}
}
iov = iovec;
}
/* Prepare for I/O. */
if ((*dp->dr_prepare)(mp->DEVICE) == NIL_DEV) return(ENXIO);
/* Transfer bytes from/to the device. */
opcode = mp->m_type;
if(opcode == DEV_GATHER_S) opcode = DEV_GATHER;
if(opcode == DEV_SCATTER_S) opcode = DEV_SCATTER;
r = (*dp->dr_transfer)(mp->IO_ENDPT, opcode, mp->POSITION, iov,
nr_req, safe);
/* Copy the I/O vector back to the caller. */
if(safe) {
if (OK != sys_safecopyto(mp->m_source, (vir_bytes) mp->IO_GRANT,
0, (vir_bytes) iovec, iovec_size, D)) {
panic((*dp->dr_name)(),"couldn't return I/O vector", mp->m_source);
}
} else {
sys_datacopy(SELF, (vir_bytes) iovec,
mp->m_source, (vir_bytes) mp->ADDRESS, iovec_size);
}
return(r);
}
/*===========================================================================*
* no_name *
*===========================================================================*/
PUBLIC char *no_name()
{
/* Use this default name if there is no specific name for the device. This was
* originally done by fetching the name from the task table for this process:
* "return(tasktab[proc_number(proc_ptr) + NR_TASKS].name);", but currently a
* real "noname" is returned. Perhaps, some system information service can be
* queried for a name at a later time.
*/
static char name[] = "noname";
return name;
}
/*============================================================================*
* do_nop *
*============================================================================*/
PUBLIC int do_nop(dp, mp)
struct driver *dp;
message *mp;
{
/* Nothing there, or nothing to do. */
switch (mp->m_type) {
case DEV_OPEN: return(ENODEV);
case DEV_CLOSE: return(OK);
case DEV_IOCTL: return(ENOTTY);
default: printf("nop: ignoring code %d\n", mp->m_type); return(EIO);
}
}
/*============================================================================*
* nop_ioctl *
*============================================================================*/
PUBLIC int nop_ioctl(dp, mp, safe)
struct driver *dp;
message *mp;
int safe;
{
return(ENOTTY);
}
/*============================================================================*
* nop_signal *
*============================================================================*/
PUBLIC void nop_signal(dp, mp)
struct driver *dp;
message *mp;
{
/* Default action for signal is to ignore. */
}
/*============================================================================*
* nop_alarm *
*============================================================================*/
PUBLIC void nop_alarm(dp, mp)
struct driver *dp;
message *mp;
{
/* Ignore the leftover alarm. */
}
/*===========================================================================*
* nop_prepare *
*===========================================================================*/
PUBLIC struct device *nop_prepare(device)
{
/* Nothing to prepare for. */
return(NIL_DEV);
}
/*===========================================================================*
* nop_cleanup *
*===========================================================================*/
PUBLIC void nop_cleanup()
{
/* Nothing to clean up. */
}
/*===========================================================================*
* nop_cancel *
*===========================================================================*/
PUBLIC int nop_cancel(struct driver *dr, message *m)
{
/* Nothing to do for cancel. */
return(OK);
}
/*===========================================================================*
* nop_select *
*===========================================================================*/
PUBLIC int nop_select(struct driver *dr, message *m)
{
/* Nothing to do for select. */
return(OK);
}
/*============================================================================*
* do_diocntl *
*============================================================================*/
PUBLIC int do_diocntl(dp, mp, safe)
struct driver *dp;
message *mp; /* pointer to ioctl request */
int safe; /* addresses or grants? */
{
/* Carry out a partition setting/getting request. */
struct device *dv;
struct partition entry;
int s;
if (mp->REQUEST != DIOCSETP && mp->REQUEST != DIOCGETP) {
if(dp->dr_other) {
return dp->dr_other(dp, mp, safe);
} else return(ENOTTY);
}
/* Decode the message parameters. */
if ((dv = (*dp->dr_prepare)(mp->DEVICE)) == NIL_DEV) return(ENXIO);
if (mp->REQUEST == DIOCSETP) {
/* Copy just this one partition table entry. */
if(safe) {
s=sys_safecopyfrom(mp->IO_ENDPT, (vir_bytes) mp->IO_GRANT,
0, (vir_bytes) &entry, sizeof(entry), D);
} else{
s=sys_datacopy(mp->IO_ENDPT, (vir_bytes) mp->ADDRESS,
SELF, (vir_bytes) &entry, sizeof(entry));
}
if(s != OK)
return s;
dv->dv_base = entry.base;
dv->dv_size = entry.size;
} else {
/* Return a partition table entry and the geometry of the drive. */
entry.base = dv->dv_base;
entry.size = dv->dv_size;
(*dp->dr_geometry)(&entry);
if(safe) {
s=sys_safecopyto(mp->IO_ENDPT, (vir_bytes) mp->IO_GRANT,
0, (vir_bytes) &entry, sizeof(entry), D);
} else {
s=sys_datacopy(SELF, (vir_bytes) &entry,
mp->IO_ENDPT, (vir_bytes) mp->ADDRESS, sizeof(entry));
}
if (OK != s)
return s;
}
return(OK);
}
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