static int hvsi_write(struct tty_struct *tty,
const unsigned char *buf, int count)
{
struct hvsi_struct *hp = tty->driver_data;
const char *source = buf;
unsigned long flags;
int total = 0;
int origcount = count;
spin_lock_irqsave(&hp->lock, flags);
pr_debug("%s: %i chars in buffer\n", __FUNCTION__, hp->n_outbuf);
if (!is_open(hp)) {
/* we're either closing or not yet open; don't accept data */
pr_debug("%s: not open\n", __FUNCTION__);
goto out;
}
/*
* when the hypervisor buffer (16K) fills, data will stay in hp->outbuf
* and hvsi_write_worker will be scheduled. subsequent hvsi_write() calls
* will see there is no room in outbuf and return.
*/
while ((count > 0) && (hvsi_write_room(hp->tty) > 0)) {
int chunksize = min(count, hvsi_write_room(hp->tty));
BUG_ON(hp->n_outbuf < 0);
memcpy(hp->outbuf + hp->n_outbuf, source, chunksize);
hp->n_outbuf += chunksize;
total += chunksize;
source += chunksize;
count -= chunksize;
hvsi_push(hp);
}
if (hp->n_outbuf > 0) {
/*
* we weren't able to write it all to the hypervisor.
* schedule another push attempt.
*/
schedule_delayed_work(&hp->writer, 10);
}
out:
spin_unlock_irqrestore(&hp->lock, flags);
if (total != origcount)
pr_debug("%s: wanted %i, only wrote %i\n", __FUNCTION__, origcount,
total);
return total;
}
/* hvsi_write_worker will keep rescheduling itself until outbuf is empty */
static void hvsi_write_worker(void *arg)
{
struct hvsi_struct *hp = (struct hvsi_struct *)arg;
unsigned long flags;
#ifdef DEBUG
static long start_j = 0;
if (start_j == 0)
start_j = jiffies;
#endif /* DEBUG */
spin_lock_irqsave(&hp->lock, flags);
pr_debug("%s: %i chars in buffer\n", __FUNCTION__, hp->n_outbuf);
if (!is_open(hp)) {
/*
* We could have a non-open connection if the service processor died
* while we were busily scheduling ourselves. In that case, it could
* be minutes before the service processor comes back, so only try
* again once a second.
*/
schedule_delayed_work(&hp->writer, HZ);
goto out;
}
hvsi_push(hp);
if (hp->n_outbuf > 0)
schedule_delayed_work(&hp->writer, 10);
else {
#ifdef DEBUG
pr_debug("%s: outbuf emptied after %li jiffies\n", __FUNCTION__,
jiffies - start_j);
start_j = 0;
#endif /* DEBUG */
wake_up_all(&hp->emptyq);
if (test_bit(TTY_DO_WRITE_WAKEUP, &hp->tty->flags)
&& hp->tty->ldisc.write_wakeup)
hp->tty->ldisc.write_wakeup(hp->tty);
wake_up_interruptible(&hp->tty->write_wait);
}
out:
spin_unlock_irqrestore(&hp->lock, flags);
}
/* hvsi_write_worker will keep rescheduling itself until outbuf is empty */
static void hvsi_write_worker(struct work_struct *work)
{
struct hvsi_struct *hp =
container_of(work, struct hvsi_struct, writer.work);
unsigned long flags;
#ifdef DEBUG
static long start_j = 0;
if (start_j == 0)
start_j = jiffies;
#endif /* DEBUG */
spin_lock_irqsave(&hp->lock, flags);
pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf);
if (!is_open(hp)) {
/*
* We could have a non-open connection if the service processor died
* while we were busily scheduling ourselves. In that case, it could
* be minutes before the service processor comes back, so only try
* again once a second.
*/
schedule_delayed_work(&hp->writer, HZ);
goto out;
}
hvsi_push(hp);
if (hp->n_outbuf > 0)
schedule_delayed_work(&hp->writer, 10);
else {
#ifdef DEBUG
pr_debug("%s: outbuf emptied after %li jiffies\n", __func__,
jiffies - start_j);
start_j = 0;
#endif /* DEBUG */
wake_up_all(&hp->emptyq);
tty_wakeup(hp->tty);
}
out:
spin_unlock_irqrestore(&hp->lock, flags);
}
