482 lines
14 KiB
C
482 lines
14 KiB
C
/* This file contains device independent device driver interface.
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*
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* Changes:
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* Jul 25, 2005 added SYS_SIG type for signals (Jorrit N. Herder)
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* Sep 15, 2004 added SYN_ALARM type for timeouts (Jorrit N. Herder)
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* Jul 23, 2004 removed kernel dependencies (Jorrit N. Herder)
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* Apr 02, 1992 constructed from AT wini and floppy driver (Kees J. Bot)
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*
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*
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* The drivers support the following operations (using message format m2):
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*
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* m_type DEVICE IO_ENDPT COUNT POSITION HIGHPOS IO_GRANT
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* ----------------------------------------------------------------------------
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* | DEV_OPEN | device | proc nr | | | | |
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* |---------------+--------+---------+---------+--------+--------+-----------|
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* | DEV_CLOSE | device | proc nr | | | | |
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* |---------------+--------+---------+---------+--------+--------+-----------|
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* | DEV_READ_S | device | proc nr | bytes | off lo | off hi i buf grant |
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* |---------------+--------+---------+---------+--------+--------+-----------|
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* | DEV_WRITE_S | device | proc nr | bytes | off lo | off hi | buf grant |
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* |---------------+--------+---------+---------+--------+--------+-----------|
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* | DEV_GATHER_S | device | proc nr | iov len | off lo | off hi | iov grant |
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* |---------------+--------+---------+---------+--------+--------+-----------|
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* | DEV_SCATTER_S | device | proc nr | iov len | off lo | off hi | iov grant |
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* |---------------+--------+---------+---------+--------+--------+-----------|
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* | DEV_IOCTL_S | device | proc nr | request | | | buf grant |
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* |---------------+--------+---------+---------+--------+--------+-----------|
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* | CANCEL | device | proc nr | r/w | | | |
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* ----------------------------------------------------------------------------
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*
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* The file contains the following entry points:
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*
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* driver_task: called by the device dependent task entry
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* init_buffer: initialize a DMA buffer
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* mq_queue: queue an incoming message for later processing
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*/
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#include <minix/drivers.h>
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#include <sys/ioc_disk.h>
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#include <minix/mq.h>
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#include <minix/endpoint.h>
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#include <minix/driver.h>
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/* Claim space for variables. */
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u8_t *tmp_buf = NULL; /* the DMA buffer eventually */
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phys_bytes tmp_phys; /* phys address of DMA buffer */
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FORWARD _PROTOTYPE( void asyn_reply, (message *mess, int proc_nr, int r) );
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FORWARD _PROTOTYPE( int do_rdwt, (struct driver *dr, message *mp) );
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FORWARD _PROTOTYPE( int do_vrdwt, (struct driver *dr, message *mp) );
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int device_caller;
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PRIVATE mq_t *queue_head = NULL;
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/*===========================================================================*
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* asyn_reply *
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*===========================================================================*/
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PRIVATE void asyn_reply(mess, proc_nr, r)
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message *mess;
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int proc_nr;
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int r;
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{
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/* Send a reply using the new asynchronous character device protocol.
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*/
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message reply_mess;
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switch (mess->m_type) {
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case DEV_OPEN:
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reply_mess.m_type = DEV_REVIVE;
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reply_mess.REP_ENDPT = proc_nr;
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reply_mess.REP_STATUS = r;
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break;
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case DEV_CLOSE:
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reply_mess.m_type = DEV_CLOSE_REPL;
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reply_mess.REP_ENDPT = proc_nr;
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reply_mess.REP_STATUS = r;
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break;
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case DEV_READ_S:
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case DEV_WRITE_S:
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if (r == SUSPEND)
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printf("driver_task: reviving %d with SUSPEND\n", proc_nr);
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reply_mess.m_type = DEV_REVIVE;
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reply_mess.REP_ENDPT = proc_nr;
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reply_mess.REP_IO_GRANT = (cp_grant_id_t) mess->IO_GRANT;
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reply_mess.REP_STATUS = r;
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break;
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case CANCEL:
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/* The original request should send a reply. */
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return;
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case DEV_SELECT:
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reply_mess.m_type = DEV_SEL_REPL1;
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reply_mess.DEV_MINOR = mess->DEVICE;
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reply_mess.DEV_SEL_OPS = r;
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break;
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default:
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reply_mess.m_type = TASK_REPLY;
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reply_mess.REP_ENDPT = proc_nr;
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/* Status is # of bytes transferred or error code. */
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reply_mess.REP_STATUS = r;
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break;
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}
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r= asynsend(device_caller, &reply_mess);
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if (r != OK)
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{
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printf("driver_task: unable to asynsend to %d: %d\n",
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device_caller, r);
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}
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}
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/*===========================================================================*
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* driver_task *
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*===========================================================================*/
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PUBLIC void driver_task(dp, type)
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struct driver *dp; /* Device dependent entry points. */
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int type; /* Driver type (DRIVER_STD or DRIVER_ASYN) */
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{
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/* Main program of any device driver task. */
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int r, proc_nr;
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message mess;
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/* Init MQ library. */
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mq_init();
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/* Here is the main loop of the disk task. It waits for a message, carries
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* it out, and sends a reply.
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*/
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while (TRUE) {
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/* Any queued messages? Oldest are at the head. */
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if(queue_head) {
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mq_t *mq;
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mq = queue_head;
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memcpy(&mess, &mq->mq_mess, sizeof(mess));
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queue_head = queue_head->mq_next;
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mq_free(mq);
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} else {
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int s;
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/* Wait for a request to read or write a disk block. */
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if ((s=sef_receive(ANY, &mess)) != OK)
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panic("sef_receive() failed: %d", s);
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}
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device_caller = mess.m_source;
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proc_nr = mess.IO_ENDPT;
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/* Now carry out the work. */
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if (is_notify(mess.m_type)) {
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switch (_ENDPOINT_P(mess.m_source)) {
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case HARDWARE:
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/* leftover interrupt or expired timer. */
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if(dp->dr_hw_int) {
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(*dp->dr_hw_int)(dp, &mess);
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}
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break;
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case CLOCK:
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(*dp->dr_alarm)(dp, &mess);
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break;
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default:
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if(dp->dr_other)
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r = (*dp->dr_other)(dp, &mess);
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else
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r = EINVAL;
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goto send_reply;
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}
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/* done, get a new message */
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continue;
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}
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switch(mess.m_type) {
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case DEV_OPEN: r = (*dp->dr_open)(dp, &mess); break;
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case DEV_CLOSE: r = (*dp->dr_close)(dp, &mess); break;
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case DEV_IOCTL_S: r = (*dp->dr_ioctl)(dp, &mess); break;
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case CANCEL: r = (*dp->dr_cancel)(dp, &mess);break;
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case DEV_SELECT: r = (*dp->dr_select)(dp, &mess);break;
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case DEV_READ_S:
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case DEV_WRITE_S: r = do_rdwt(dp, &mess); break;
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case DEV_GATHER_S:
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case DEV_SCATTER_S: r = do_vrdwt(dp, &mess); break;
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default:
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if(dp->dr_other)
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r = (*dp->dr_other)(dp, &mess);
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else
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r = EINVAL;
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break;
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}
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send_reply:
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/* Clean up leftover state. */
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(*dp->dr_cleanup)();
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/* Finally, prepare and send the reply message. */
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if (r == EDONTREPLY)
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continue;
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switch (type) {
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case DRIVER_STD:
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mess.m_type = TASK_REPLY;
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mess.REP_ENDPT = proc_nr;
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/* Status is # of bytes transferred or error code. */
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mess.REP_STATUS = r;
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/* Changed from sendnb() to asynsend() by dcvmoole on 20091129.
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* This introduces a potential overflow if a single process is
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* flooding us with requests, but we need reliable delivery of
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* reply messages for the 'filter' driver. A possible solution
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* would be to allow only one pending asynchronous reply to a
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* single process at any time. FIXME.
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*/
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r= asynsend(device_caller, &mess);
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if (r != OK)
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{
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printf("driver_task: unable to send reply to %d: %d\n",
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device_caller, r);
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}
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break;
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case DRIVER_ASYN:
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asyn_reply(&mess, proc_nr, r);
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break;
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default:
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panic("unknown driver type: %d", type);
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}
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}
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}
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/*===========================================================================*
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* init_buffer *
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*===========================================================================*/
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PUBLIC void init_buffer(void)
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{
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/* Select a buffer that can safely be used for DMA transfers. It may also
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* be used to read partition tables and such. Its absolute address is
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* 'tmp_phys', the normal address is 'tmp_buf'.
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*/
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if(!(tmp_buf = alloc_contig(2*DMA_BUF_SIZE, AC_ALIGN4K, &tmp_phys)))
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panic("can't allocate tmp_buf: %d", DMA_BUF_SIZE);
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}
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/*===========================================================================*
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* do_rdwt *
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*===========================================================================*/
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PRIVATE int do_rdwt(dp, mp)
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struct driver *dp; /* device dependent entry points */
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message *mp; /* pointer to read or write message */
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{
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/* Carry out a single read or write request. */
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iovec_t iovec1;
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int r, opcode;
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u64_t position;
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/* Disk address? Address and length of the user buffer? */
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if (mp->COUNT < 0) return(EINVAL);
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/* Prepare for I/O. */
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if ((*dp->dr_prepare)(mp->DEVICE) == NIL_DEV) return(ENXIO);
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/* Create a one element scatter/gather vector for the buffer. */
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if(mp->m_type == DEV_READ_S) opcode = DEV_GATHER_S;
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else opcode = DEV_SCATTER_S;
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iovec1.iov_addr = (vir_bytes) mp->IO_GRANT;
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iovec1.iov_size = mp->COUNT;
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/* Transfer bytes from/to the device. */
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position= make64(mp->POSITION, mp->HIGHPOS);
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r = (*dp->dr_transfer)(mp->IO_ENDPT, opcode, position, &iovec1, 1);
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/* Return the number of bytes transferred or an error code. */
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return(r == OK ? (mp->COUNT - iovec1.iov_size) : r);
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}
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/*==========================================================================*
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* do_vrdwt *
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*==========================================================================*/
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PRIVATE int do_vrdwt(dp, mp)
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struct driver *dp; /* device dependent entry points */
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message *mp; /* pointer to read or write message */
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{
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/* Carry out an device read or write to/from a vector of user addresses.
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* The "user addresses" are assumed to be safe, i.e. FS transferring to/from
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* its own buffers, so they are not checked.
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*/
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static iovec_t iovec[NR_IOREQS];
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phys_bytes iovec_size;
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unsigned nr_req;
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int r, opcode;
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u64_t position;
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nr_req = mp->COUNT; /* Length of I/O vector */
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/* Copy the vector from the caller to kernel space. */
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if (nr_req > NR_IOREQS) nr_req = NR_IOREQS;
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iovec_size = (phys_bytes) (nr_req * sizeof(iovec[0]));
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if (OK != sys_safecopyfrom(mp->m_source, (vir_bytes) mp->IO_GRANT,
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0, (vir_bytes) iovec, iovec_size, D)) {
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panic("bad I/O vector by: %d", mp->m_source);
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}
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/* Prepare for I/O. */
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if ((*dp->dr_prepare)(mp->DEVICE) == NIL_DEV) return(ENXIO);
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/* Transfer bytes from/to the device. */
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opcode = mp->m_type;
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position= make64(mp->POSITION, mp->HIGHPOS);
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r = (*dp->dr_transfer)(mp->IO_ENDPT, opcode, position, iovec, nr_req);
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/* Copy the I/O vector back to the caller. */
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if (OK != sys_safecopyto(mp->m_source, (vir_bytes) mp->IO_GRANT,
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0, (vir_bytes) iovec, iovec_size, D)) {
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panic("couldn't return I/O vector: %d", mp->m_source);
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}
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return(r);
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}
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/*===========================================================================*
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* no_name *
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*===========================================================================*/
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PUBLIC char *no_name()
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{
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/* Use this default name if there is no specific name for the device. This was
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* originally done by fetching the name from the task table for this process:
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* "return(tasktab[proc_number(proc_ptr) + NR_TASKS].name);", but currently a
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* real "noname" is returned. Perhaps, some system information service can be
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* queried for a name at a later time.
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*/
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static char name[] = "noname";
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return name;
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}
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/*============================================================================*
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* do_nop *
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*============================================================================*/
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PUBLIC int do_nop(dp, mp)
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struct driver *dp;
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message *mp;
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{
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/* Nothing there, or nothing to do. */
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switch (mp->m_type) {
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case DEV_OPEN: return(ENODEV);
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case DEV_CLOSE: return(OK);
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case DEV_IOCTL_S:
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default: printf("nop: ignoring code %d\n", mp->m_type);
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return(EIO);
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}
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}
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/*============================================================================*
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* nop_ioctl *
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*============================================================================*/
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PUBLIC int nop_ioctl(dp, mp)
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struct driver *dp;
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message *mp;
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{
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return(ENOTTY);
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}
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/*============================================================================*
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* nop_alarm *
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*============================================================================*/
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PUBLIC void nop_alarm(dp, mp)
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struct driver *dp;
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message *mp;
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{
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/* Ignore the leftover alarm. */
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}
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/*===========================================================================*
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* nop_prepare *
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*===========================================================================*/
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PUBLIC struct device *nop_prepare(int device)
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{
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/* Nothing to prepare for. */
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return(NIL_DEV);
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}
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/*===========================================================================*
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* nop_cleanup *
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*===========================================================================*/
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PUBLIC void nop_cleanup()
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{
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/* Nothing to clean up. */
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}
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/*===========================================================================*
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* nop_cancel *
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*===========================================================================*/
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PUBLIC int nop_cancel(struct driver *dr, message *m)
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{
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/* Nothing to do for cancel. */
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return(OK);
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}
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/*===========================================================================*
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* nop_select *
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*===========================================================================*/
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PUBLIC int nop_select(struct driver *dr, message *m)
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{
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/* Nothing to do for select. */
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return(OK);
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}
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/*============================================================================*
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* do_diocntl *
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*============================================================================*/
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PUBLIC int do_diocntl(dp, mp)
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struct driver *dp;
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message *mp; /* pointer to ioctl request */
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{
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/* Carry out a partition setting/getting request. */
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struct device *dv;
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struct partition entry;
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int s;
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if (mp->REQUEST != DIOCSETP && mp->REQUEST != DIOCGETP) {
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if(dp->dr_other) {
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return dp->dr_other(dp, mp);
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} else return(ENOTTY);
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}
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/* Decode the message parameters. */
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if ((dv = (*dp->dr_prepare)(mp->DEVICE)) == NIL_DEV) return(ENXIO);
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if (mp->REQUEST == DIOCSETP) {
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/* Copy just this one partition table entry. */
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s=sys_safecopyfrom(mp->IO_ENDPT, (vir_bytes) mp->IO_GRANT,
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0, (vir_bytes) &entry, sizeof(entry), D);
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if(s != OK)
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return s;
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dv->dv_base = entry.base;
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dv->dv_size = entry.size;
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} else {
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/* Return a partition table entry and the geometry of the drive. */
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entry.base = dv->dv_base;
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entry.size = dv->dv_size;
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(*dp->dr_geometry)(&entry);
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s=sys_safecopyto(mp->IO_ENDPT, (vir_bytes) mp->IO_GRANT,
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0, (vir_bytes) &entry, sizeof(entry), D);
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if (OK != s)
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return s;
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}
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return(OK);
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}
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/*===========================================================================*
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* mq_queue *
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*===========================================================================*/
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PUBLIC int mq_queue(message *m)
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{
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mq_t *mq, *mi;
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if(!(mq = mq_get()))
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panic("mq_queue: mq_get failed");
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memcpy(&mq->mq_mess, m, sizeof(mq->mq_mess));
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mq->mq_next = NULL;
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if(!queue_head) {
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queue_head = mq;
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} else {
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for(mi = queue_head; mi->mq_next; mi = mi->mq_next)
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;
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mi->mq_next = mq;
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}
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return OK;
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}
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