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Subject[PATCH 46/69] TTY: hvsi, use tty from tty_port
Date
Now, we switch to the refcounted model and do not need hp->lock to
protect hp->tty anymore.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: linuxppc-dev@lists.ozlabs.org
---
drivers/tty/hvc/hvsi.c | 35 +++++++++++++++++++++--------------
1 file changed, 21 insertions(+), 14 deletions(-)

diff --git a/drivers/tty/hvc/hvsi.c b/drivers/tty/hvc/hvsi.c
index 68b729b..6f5bc49 100644
--- a/drivers/tty/hvc/hvsi.c
+++ b/drivers/tty/hvc/hvsi.c
@@ -76,7 +76,6 @@ struct hvsi_struct {
wait_queue_head_t stateq; /* woken when HVSI state changes */
spinlock_t lock;
int index;
- struct tty_struct *tty;
uint8_t throttle_buf[128];
uint8_t outbuf[N_OUTBUF]; /* to implement write_room and chars_in_buffer */
/* inbuf is for packet reassembly. leave a little room for leftovers. */
@@ -492,14 +491,17 @@ static irqreturn_t hvsi_interrupt(int irq, void *arg)
{
struct hvsi_struct *hp = (struct hvsi_struct *)arg;
struct hvsi_struct *handshake;
+ struct tty_struct *tty;
unsigned long flags;
int again = 1;

pr_debug("%s\n", __func__);

+ tty = tty_port_tty_get(&hp->port);
+
while (again) {
spin_lock_irqsave(&hp->lock, flags);
- again = hvsi_load_chunk(hp, hp->tty, &handshake);
+ again = hvsi_load_chunk(hp, tty, &handshake);
spin_unlock_irqrestore(&hp->lock, flags);

if (handshake) {
@@ -509,15 +511,16 @@ static irqreturn_t hvsi_interrupt(int irq, void *arg)
}

spin_lock_irqsave(&hp->lock, flags);
- if (hp->tty && hp->n_throttle
- && (!test_bit(TTY_THROTTLED, &hp->tty->flags))) {
- /* we weren't hung up and we weren't throttled, so we can deliver the
- * rest now */
- hvsi_send_overflow(hp, hp->tty);
- tty_flip_buffer_push(hp->tty);
+ if (tty && hp->n_throttle && !test_bit(TTY_THROTTLED, &tty->flags)) {
+ /* we weren't hung up and we weren't throttled, so we can
+ * deliver the rest now */
+ hvsi_send_overflow(hp, tty);
+ tty_flip_buffer_push(tty);
}
spin_unlock_irqrestore(&hp->lock, flags);

+ tty_kref_put(tty);
+
return IRQ_HANDLED;
}

@@ -724,8 +727,8 @@ static int hvsi_open(struct tty_struct *tty, struct file *filp)
if (hp->state == HVSI_FSP_DIED)
return -EIO;

+ tty_port_tty_set(&hp->port, tty);
spin_lock_irqsave(&hp->lock, flags);
- hp->tty = tty;
hp->port.count++;
atomic_set(&hp->seqno, 0);
h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
@@ -784,7 +787,7 @@ static void hvsi_close(struct tty_struct *tty, struct file *filp)
spin_lock_irqsave(&hp->lock, flags);

if (--hp->port.count == 0) {
- hp->tty = NULL;
+ tty_port_tty_set(&hp->port, NULL);
hp->inbuf_end = hp->inbuf; /* discard remaining partial packets */

/* only close down connection if it is not the console */
@@ -830,12 +833,11 @@ static void hvsi_hangup(struct tty_struct *tty)

pr_debug("%s\n", __func__);

- spin_lock_irqsave(&hp->lock, flags);
+ tty_port_tty_set(&hp->port, NULL);

+ spin_lock_irqsave(&hp->lock, flags);
hp->port.count = 0;
hp->n_outbuf = 0;
- hp->tty = NULL;
-
spin_unlock_irqrestore(&hp->lock, flags);
}

@@ -863,6 +865,7 @@ static void hvsi_write_worker(struct work_struct *work)
{
struct hvsi_struct *hp =
container_of(work, struct hvsi_struct, writer.work);
+ struct tty_struct *tty;
unsigned long flags;
#ifdef DEBUG
static long start_j = 0;
@@ -896,7 +899,11 @@ static void hvsi_write_worker(struct work_struct *work)
start_j = 0;
#endif /* DEBUG */
wake_up_all(&hp->emptyq);
- tty_wakeup(hp->tty);
+ tty = tty_port_tty_get(&hp->port);
+ if (tty) {
+ tty_wakeup(tty);
+ tty_kref_put(tty);
+ }
}

out:
--
1.7.9.2



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