tapeblock.c

移植到2410开发板上的源代码

	if (ti->request_queue==NULL) {
#endif
	// nothing more to do or device has dissapeared;)
#ifdef TAPE_DEBUG
	debug_text_event (tape_debug_area,6,"b:Qempty");
#endif
	tapestate_set(ti,TS_IDLE);
	return;
    }
    // queue is not empty, fetch a request and start IO!
    req=ti->current_request=tape_next_request(&ti->request_queue);
    if (req==NULL) {
	BUG(); // Yo. The queue was not reported empy, but no request found. This is _bad_.
    }
    if (req->cmd!=READ) { // we only support reading
	tapestate_set(ti,TS_FAILED);
	tapeblock_end_request (ti); // check state, inform user, free mem, dev=idl
	tapestate_set(ti,TS_BLOCK_INIT);
	schedule_tapeblock_exec_IO(ti);
	return;
    }
    ti->cqr=ti->discipline->bread(req,ti,tapeblock_major); //build channel program from request
    if (!ti->cqr) {
	// ccw generation failed. we try again later.
#ifdef TAPE_DEBUG
	debug_text_event (tape_debug_area,3,"b:cqrNULL");
#endif
	schedule_tapeblock_exec_IO(ti);
	ti->current_request=NULL;
	return;
    }
    ti->blk_retries = TAPEBLOCK_RETRIES;
    rc= do_IO (ti->devinfo.irq, ti->cqr->cpaddr, 
	       (unsigned long) ti->cqr, 0x00, ti->cqr->options);
    if (rc) {
	// okay. ssch failed. we try later.
#ifdef TAPE_DEBUG
	debug_text_event (tape_debug_area,3,"b:doIOfail");
#endif
	ti->discipline->free_bread(ti->cqr,ti);
	ti->cqr=NULL;
	ti->current_request=NULL;
	schedule_tapeblock_exec_IO(ti);
	return;
    }
    // our request is in IO. we remove it from the queue and exit
    tape_dequeue_request (&ti->request_queue,req);
}

static void 
do_tape_request (request_queue_t * queue) {
    tape_info_t* ti;
    long lockflags;
    for (ti=first_tape_info;
	 ((ti!=NULL) && ((&ti->request_queue)!=queue));
	 ti=ti->next);
    if (ti==NULL) BUG();
    s390irq_spin_lock_irqsave (ti->devinfo.irq, lockflags);
    if (tapestate_get(ti)!=TS_IDLE) {
	s390irq_spin_unlock_irqrestore(ti->devinfo.irq,lockflags);
	return;
    }
    if (tapestate_get(ti)!=TS_IDLE) BUG();
    tapestate_set(ti,TS_BLOCK_INIT);
    tapeblock_exec_IO(ti);
    s390irq_spin_unlock_irqrestore(ti->devinfo.irq,lockflags);
}

static void
run_tapeblock_exec_IO (tape_info_t* ti) {
    long flags_390irq,flags_ior;
    spin_lock_irqsave (&io_request_lock, flags_ior);
    s390irq_spin_lock_irqsave(ti->devinfo.irq,flags_390irq);
    atomic_set(&ti->bh_scheduled,0);
    tapeblock_exec_IO(ti);
    s390irq_spin_unlock_irqrestore(ti->devinfo.irq,flags_390irq);
    spin_unlock_irqrestore (&io_request_lock, flags_ior);
}

void
schedule_tapeblock_exec_IO (tape_info_t *ti)
{
	/* Protect against rescheduling, when already running */
        if (atomic_compare_and_swap(0,1,&ti->bh_scheduled)) {
                return;
        }
#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,3,98))
	INIT_LIST_HEAD(&ti->bh_tq.list);
#endif
	ti->bh_tq.sync = 0;
	ti->bh_tq.routine = (void *) (void *) run_tapeblock_exec_IO;
	ti->bh_tq.data = ti;

	queue_task (&ti->bh_tq, &tq_immediate);
	mark_bh (IMMEDIATE_BH);
	return;
}

/* wrappers around do_tape_request for different kernel versions */
#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,3,98))
static void tape_request_fn (void) {
    tape_info_t* ti=first_tape_info;
    while (ti!=NULL) {
	do_tape_request(&ti->request_queue);
	ti=ti->next;
    }
}
#else
static void  tape_request_fn (request_queue_t* queue) {
    do_tape_request(queue);
}
#endif

static request_queue_t* tapeblock_getqueue (kdev_t kdev) {
    tape_info_t* ti=first_tape_info;
    while ((ti!=NULL) && (MINOR(kdev)!=ti->blk_minor)) 
        ti=ti->next;
    if (ti!=NULL) return &ti->request_queue;
    return NULL;
}

int tapeblock_mediumdetect(tape_info_t* ti) {
        ccw_req_t* cqr;
    int losize=1,hisize=1,rc;
    long lockflags;
#ifdef TAPE_DEBUG
    debug_text_event (tape_debug_area,3,"b:medDet");
#endif
    PRINT_WARN("Detecting media size. This will take _long_, so get yourself a coffee...\n");
    while (1) { //is interruped by break
	hisize=hisize << 1; // try twice the size tested before 
	cqr=ti->discipline->mtseek (ti, hisize);
	if (cqr == NULL) {
#ifdef TAPE_DEBUG
	    debug_text_event (tape_debug_area,6,"b:ccwg fail");
#endif
	    return -ENOSPC;
	}
	s390irq_spin_lock_irqsave (ti->devinfo.irq, lockflags);
	ti->cqr = cqr;
	ti->wanna_wakeup=0;
	rc = do_IO (ti->devinfo.irq, cqr->cpaddr, (unsigned long) cqr, 0x00, cqr->options);
	s390irq_spin_unlock_irqrestore (ti->devinfo.irq, lockflags);
	if (rc) return -EIO;
	wait_event_interruptible (ti->wq,ti->wanna_wakeup);
	ti->cqr = NULL;
	tape_free_request (cqr);
	if (ti->kernbuf) {
	    kfree (ti->kernbuf);
	    ti->kernbuf=NULL;
	}
	if (signal_pending (current)) {
		tapestate_set (ti, TS_IDLE);
		return -ERESTARTSYS;
	}
	s390irq_spin_lock_irqsave (ti->devinfo.irq, lockflags);
	if (tapestate_get (ti) == TS_FAILED) {
		tapestate_set (ti, TS_IDLE);
		s390irq_spin_unlock_irqrestore (ti->devinfo.irq, lockflags);
		break;
	}
	if (tapestate_get (ti) == TS_NOT_OPER) {
	    ti->blk_minor=ti->rew_minor=ti->nor_minor=-1;
	    ti->devinfo.irq=-1;
	    s390irq_spin_unlock_irqrestore (ti->devinfo.irq,lockflags);
	    return -ENODEV;
	}
	if (tapestate_get (ti) != TS_DONE) {
		tapestate_set (ti, TS_IDLE);
		s390irq_spin_unlock_irqrestore (ti->devinfo.irq, lockflags);
		return -EIO;
	}
	tapestate_set (ti, TS_IDLE);
	s390irq_spin_unlock_irqrestore (ti->devinfo.irq, lockflags);
	losize=hisize;
    }
    cqr = ti->discipline->mtrew (ti, 1);
    if (cqr == NULL) {
#ifdef TAPE_DEBUG
	debug_text_event (tape_debug_area,6,"b:ccwg fail");
#endif
	return -ENOSPC;
    }
    s390irq_spin_lock_irqsave (ti->devinfo.irq, lockflags);
    ti->cqr = cqr;
    ti->wanna_wakeup=0;
    rc = do_IO (ti->devinfo.irq, cqr->cpaddr, (unsigned long) cqr, 0x00, cqr->options);
    s390irq_spin_unlock_irqrestore (ti->devinfo.irq, lockflags);
    wait_event_interruptible (ti->wq,ti->wanna_wakeup);
    ti->cqr = NULL;
    tape_free_request (cqr);
    if (signal_pending (current)) {
	tapestate_set (ti, TS_IDLE);
	return -ERESTARTSYS;
    }
    s390irq_spin_lock_irqsave (ti->devinfo.irq, lockflags);
    if (tapestate_get (ti) == TS_FAILED) {
	tapestate_set (ti, TS_IDLE);
	s390irq_spin_unlock_irqrestore (ti->devinfo.irq, lockflags);
	return -EIO;
    }
    if (tapestate_get (ti) == TS_NOT_OPER) {
	ti->blk_minor=ti->rew_minor=ti->nor_minor=-1;
	ti->devinfo.irq=-1;
	s390irq_spin_unlock_irqrestore (ti->devinfo.irq,lockflags);
	return -ENODEV;
    }
    if (tapestate_get (ti) != TS_DONE) {
	tapestate_set (ti, TS_IDLE);
	s390irq_spin_unlock_irqrestore (ti->devinfo.irq, lockflags);
	return -EIO;
    }
    tapestate_set (ti, TS_IDLE);
    s390irq_spin_unlock_irqrestore (ti->devinfo.irq, lockflags);
    while (losize!=hisize) {
	cqr=ti->discipline->mtseek (ti, (hisize+losize)/2+1);
	if (cqr == NULL) {
#ifdef TAPE_DEBUG
	    debug_text_event (tape_debug_area,6,"b:ccwg fail");
#endif
	    return -ENOSPC;
	}
	s390irq_spin_lock_irqsave (ti->devinfo.irq, lockflags);
	ti->cqr = cqr;
	ti->wanna_wakeup=0;
	rc = do_IO (ti->devinfo.irq, cqr->cpaddr, (unsigned long) cqr, 0x00, cqr->options);
	s390irq_spin_unlock_irqrestore (ti->devinfo.irq, lockflags);
	if (rc) return -EIO;
	wait_event_interruptible (ti->wq,ti->wanna_wakeup);
	ti->cqr = NULL;
	tape_free_request (cqr);
	if (ti->kernbuf) {
	    kfree (ti->kernbuf);
	    ti->kernbuf=NULL;
	}
	if (signal_pending (current)) {
		tapestate_set (ti, TS_IDLE);
		return -ERESTARTSYS;
	}
	s390irq_spin_lock_irqsave (ti->devinfo.irq, lockflags);
	if (tapestate_get (ti) == TS_NOT_OPER) {
	    ti->blk_minor=ti->rew_minor=ti->nor_minor=-1;
	    ti->devinfo.irq=-1;
	    s390irq_spin_unlock_irqrestore (ti->devinfo.irq,lockflags);
	    return -ENODEV;
	}
	if (tapestate_get (ti) == TS_FAILED) {
		tapestate_set (ti, TS_IDLE);
		s390irq_spin_unlock_irqrestore (ti->devinfo.irq, lockflags);
		hisize=(hisize+losize)/2;
		cqr = ti->discipline->mtrew (ti, 1);
		if (cqr == NULL) {
#ifdef TAPE_DEBUG
		    debug_text_event (tape_debug_area,6,"b:ccwg fail");
#endif
		    return -ENOSPC;
		}
		s390irq_spin_lock_irqsave (ti->devinfo.irq, lockflags);
		ti->cqr = cqr;
		ti->wanna_wakeup=0;
		rc = do_IO (ti->devinfo.irq, cqr->cpaddr, (unsigned long) cqr, 0x00, cqr->options);
		s390irq_spin_unlock_irqrestore (ti->devinfo.irq, lockflags);
		wait_event_interruptible (ti->wq,ti->wanna_wakeup);
		ti->cqr = NULL;
		tape_free_request (cqr);
		if (signal_pending (current)) {
		    tapestate_set (ti, TS_IDLE);
		    return -ERESTARTSYS;
		}
		s390irq_spin_lock_irqsave (ti->devinfo.irq, lockflags);
		if (tapestate_get (ti) == TS_FAILED) {
		    tapestate_set (ti, TS_IDLE);
		    s390irq_spin_unlock_irqrestore (ti->devinfo.irq, lockflags);
		    return -EIO;
		}
		if (tapestate_get (ti) != TS_DONE) {
		    tapestate_set (ti, TS_IDLE);
		    s390irq_spin_unlock_irqrestore (ti->devinfo.irq, lockflags);
		    return -EIO;
		}
		tapestate_set (ti, TS_IDLE);
		s390irq_spin_unlock_irqrestore (ti->devinfo.irq, lockflags);
		continue;
	}
	if (tapestate_get (ti) != TS_DONE) {
		tapestate_set (ti, TS_IDLE);
		s390irq_spin_unlock_irqrestore (ti->devinfo.irq, lockflags);
		return -EIO;
	}
	tapestate_set (ti, TS_IDLE);
	s390irq_spin_unlock_irqrestore (ti->devinfo.irq, lockflags);
	losize=(hisize+losize)/2+1;
    }
    blk_size[tapeblock_major][ti->blk_minor]=(losize)*(blksize_size[tapeblock_major][ti->blk_minor]/1024);
    return 0;
}