[PATCH 24/69] TTY: con3215, centralize allocation

[PATCH 24/69] TTY: con3215, centralize allocation

[Jiri Slaby]

There are two copies of allocations of device information. One of them
is totally broken. See:
raw->cdev = cdev;
raw->inbuf = (char *) raw + sizeof(struct raw3215_info);
memset(raw, 0, sizeof(struct raw3215_info));

It suggests that this path was never executed. The code uses both
raw->cdev and raw->inbuf all over. And it is NULL due to the memset
here, so it would panic immediately. I believe nobody used that driver
without being a system console.

Either way, let us fix it by moving the allocations (and
initializations) to a single place. This will save us some double
initializations later too.

And while at it, initialize the timer properly -- once, at the
allocation.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
---
 drivers/s390/char/con3215.c |   74 +++++++++++++++++++++++--------------------
 1 file changed, 39 insertions(+), 35 deletions(-)

diff --git a/drivers/s390/char/con3215.c b/drivers/s390/char/con3215.c
index 4f9f1dc..7e30f85 100644
--- a/drivers/s390/char/con3215.c
+++ b/drivers/s390/char/con3215.c
@@ -324,10 +324,7 @@ static inline void raw3215_try_io(struct raw3215_info *raw)
 			}
 		} else if (!(raw->flags & RAW3215_TIMER_RUNS)) {
 			/* delay small writes */
-			init_timer(&raw->timer);
 			raw->timer.expires = RAW3215_TIMEOUT + jiffies;
-			raw->timer.data = (unsigned long) raw;
-			raw->timer.function = raw3215_timeout;
 			add_timer(&raw->timer);
 			raw->flags |= RAW3215_TIMER_RUNS;
 		}
@@ -648,6 +645,35 @@ static void raw3215_shutdown(struct raw3215_info *raw)
 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
 }
 
+static struct raw3215_info *raw3215_alloc_info(void)
+{
+	struct raw3215_info *info;
+
+	info = kzalloc(sizeof(struct raw3215_info), GFP_KERNEL | GFP_DMA);
+	if (!info)
+		return NULL;
+
+	info->buffer = kzalloc(RAW3215_BUFFER_SIZE, GFP_KERNEL | GFP_DMA);
+	info->inbuf = kzalloc(RAW3215_INBUF_SIZE, GFP_KERNEL | GFP_DMA);
+	if (!info->buffer || !info->inbuf) {
+		kfree(info);
+		return NULL;
+	}
+
+	setup_timer(&info->timer, raw3215_timeout, (unsigned long)info);
+	init_waitqueue_head(&info->empty_wait);
+	tasklet_init(&info->tlet, raw3215_wakeup, (unsigned long)info);
+
+	return info;
+}
+
+static void raw3215_free_info(struct raw3215_info *raw)
+{
+	kfree(raw->inbuf);
+	kfree(raw->buffer);
+	kfree(raw);
+}
+
 static int raw3215_probe (struct ccw_device *cdev)
 {
 	struct raw3215_info *raw;
@@ -656,11 +682,15 @@ static int raw3215_probe (struct ccw_device *cdev)
 	/* Console is special. */
 	if (raw3215[0] && (raw3215[0] == dev_get_drvdata(&cdev->dev)))
 		return 0;
-	raw = kmalloc(sizeof(struct raw3215_info) +
-		      RAW3215_INBUF_SIZE, GFP_KERNEL|GFP_DMA);
+
+	raw = raw3215_alloc_info();
 	if (raw == NULL)
 		return -ENOMEM;
 
+	raw->cdev = cdev;
+	dev_set_drvdata(&cdev->dev, raw);
+	cdev->handler = raw3215_irq;
+
 	spin_lock(&raw3215_device_lock);
 	for (line = 0; line < NR_3215; line++) {
 		if (!raw3215[line]) {
@@ -670,28 +700,10 @@ static int raw3215_probe (struct ccw_device *cdev)
 	}
 	spin_unlock(&raw3215_device_lock);
 	if (line == NR_3215) {
-		kfree(raw);
+		raw3215_free_info(raw);
 		return -ENODEV;
 	}
 
-	raw->cdev = cdev;
-	raw->inbuf = (char *) raw + sizeof(struct raw3215_info);
-	memset(raw, 0, sizeof(struct raw3215_info));
-	raw->buffer = kmalloc(RAW3215_BUFFER_SIZE,
-				       GFP_KERNEL|GFP_DMA);
-	if (raw->buffer == NULL) {
-		spin_lock(&raw3215_device_lock);
-		raw3215[line] = NULL;
-		spin_unlock(&raw3215_device_lock);
-		kfree(raw);
-		return -ENOMEM;
-	}
-	init_waitqueue_head(&raw->empty_wait);
-	tasklet_init(&raw->tlet, raw3215_wakeup, (unsigned long) raw);
-
-	dev_set_drvdata(&cdev->dev, raw);
-	cdev->handler = raw3215_irq;
-
 	return 0;
 }
 
@@ -703,8 +715,7 @@ static void raw3215_remove (struct ccw_device *cdev)
 	raw = dev_get_drvdata(&cdev->dev);
 	if (raw) {
 		dev_set_drvdata(&cdev->dev, NULL);
-		kfree(raw->buffer);
-		kfree(raw);
+		raw3215_free_info(raw);
 	}
 }
 
@@ -897,23 +908,16 @@ static int __init con3215_init(void)
 	if (IS_ERR(cdev))
 		return -ENODEV;
 
-	raw3215[0] = raw = (struct raw3215_info *)
-		kzalloc(sizeof(struct raw3215_info), GFP_KERNEL | GFP_DMA);
-	raw->buffer = kzalloc(RAW3215_BUFFER_SIZE, GFP_KERNEL | GFP_DMA);
-	raw->inbuf = kzalloc(RAW3215_INBUF_SIZE, GFP_KERNEL | GFP_DMA);
+	raw3215[0] = raw = raw3215_alloc_info();
 	raw->cdev = cdev;
 	dev_set_drvdata(&cdev->dev, raw);
 	cdev->handler = raw3215_irq;
 
 	raw->flags |= RAW3215_FIXED;
-	init_waitqueue_head(&raw->empty_wait);
-	tasklet_init(&raw->tlet, raw3215_wakeup, (unsigned long) raw);
 
 	/* Request the console irq */
 	if (raw3215_startup(raw) != 0) {
-		kfree(raw->inbuf);
-		kfree(raw->buffer);
-		kfree(raw);
+		raw3215_free_info(raw);
 		raw3215[0] = NULL;
 		return -ENODEV;
 	}
-- 
1.7.9.2

Re: [PATCH 24/69] TTY: con3215, centralize allocation

[Heiko Carstens]

On Mon, Apr 02, 2012 at 01:54:08PM +0200, Jiri Slaby wrote:
> There are two copies of allocations of device information. One of them
> is totally broken. See:
> raw->cdev = cdev;
> raw->inbuf = (char *) raw + sizeof(struct raw3215_info);
> memset(raw, 0, sizeof(struct raw3215_info));
> 
> It suggests that this path was never executed. The code uses both
> raw->cdev and raw->inbuf all over. And it is NULL due to the memset
> here, so it would panic immediately. I believe nobody used that driver
> without being a system console.
> 
> Either way, let us fix it by moving the allocations (and
> initializations) to a single place. This will save us some double
> initializations later too.
> 
> And while at it, initialize the timer properly -- once, at the
> allocation.
> 
> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
> Cc: linux390@de.ibm.com
> Cc: linux-s390@vger.kernel.org
> ---
>  drivers/s390/char/con3215.c |   74 +++++++++++++++++++++++--------------------
>  1 file changed, 39 insertions(+), 35 deletions(-)

Nice!

Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>

[PATCH 25/69] TTY: con3215, remove tasklet for tty_wakeup

[Jiri Slaby]

tty_wakeup is safe to be called from all contexts. No need to schedule
a tasklet for that. Let us call it directly like in other drivers.

And delete the tasklet completely.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
---
 drivers/s390/char/con3215.c |   14 +-------------
 1 file changed, 1 insertion(+), 13 deletions(-)

diff --git a/drivers/s390/char/con3215.c b/drivers/s390/char/con3215.c
index 7e30f85..fb195f3 100644
--- a/drivers/s390/char/con3215.c
+++ b/drivers/s390/char/con3215.c
@@ -87,7 +87,6 @@ struct raw3215_info {
 	struct tty_struct *tty;	      /* pointer to tty structure if present */
 	struct raw3215_req *queued_read; /* pointer to queued read requests */
 	struct raw3215_req *queued_write;/* pointer to queued write requests */
-	struct tasklet_struct tlet;   /* tasklet to invoke tty_wakeup */
 	wait_queue_head_t empty_wait; /* wait queue for flushing */
 	struct timer_list timer;      /* timer for delayed output */
 	int line_pos;		      /* position on the line (for tabs) */
@@ -332,15 +331,6 @@ static inline void raw3215_try_io(struct raw3215_info *raw)
 }
 
 /*
- * Call tty_wakeup from tasklet context
- */
-static void raw3215_wakeup(unsigned long data)
-{
-	struct raw3215_info *raw = (struct raw3215_info *) data;
-	tty_wakeup(raw->tty);
-}
-
-/*
  * Try to start the next IO and wake up processes waiting on the tty.
  */
 static void raw3215_next_io(struct raw3215_info *raw)
@@ -348,7 +338,7 @@ static void raw3215_next_io(struct raw3215_info *raw)
 	raw3215_mk_write_req(raw);
 	raw3215_try_io(raw);
 	if (raw->tty && RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE)
-		tasklet_schedule(&raw->tlet);
+		tty_wakeup(raw->tty);
 }
 
 /*
@@ -662,7 +652,6 @@ static struct raw3215_info *raw3215_alloc_info(void)
 
 	setup_timer(&info->timer, raw3215_timeout, (unsigned long)info);
 	init_waitqueue_head(&info->empty_wait);
-	tasklet_init(&info->tlet, raw3215_wakeup, (unsigned long)info);
 
 	return info;
 }
@@ -973,7 +962,6 @@ static void tty3215_close(struct tty_struct *tty, struct file * filp)
 	tty->closing = 1;
 	/* Shutdown the terminal */
 	raw3215_shutdown(raw);
-	tasklet_kill(&raw->tlet);
 	tty->closing = 0;
 	raw->tty = NULL;
 }
-- 
1.7.9.2

Re: [PATCH 25/69] TTY: con3215, remove tasklet for tty_wakeup

[Heiko Carstens]

On Mon, Apr 02, 2012 at 01:54:09PM +0200, Jiri Slaby wrote:
> tty_wakeup is safe to be called from all contexts. No need to schedule
> a tasklet for that. Let us call it directly like in other drivers.
> 
> And delete the tasklet completely.

Your patch actually reverts Martin's recent commit 656d912537
"[S390] 3215 deadlock with tty_wakeup".
I'm quite sure the reason for the deadlock still exists.
Unfortunately the commit doesn't contain the call chain that
led to fix.

Re: [PATCH 25/69] TTY: con3215, remove tasklet for tty_wakeup

[Jiri Slaby]

On 04/03/2012 07:42 AM, Heiko Carstens wrote:
> On Mon, Apr 02, 2012 at 01:54:09PM +0200, Jiri Slaby wrote:
>> tty_wakeup is safe to be called from all contexts. No need to schedule
>> a tasklet for that. Let us call it directly like in other drivers.
>>
>> And delete the tasklet completely.
> 
> Your patch actually reverts Martin's recent commit 656d912537
> "[S390] 3215 deadlock with tty_wakeup".
> I'm quite sure the reason for the deadlock still exists.
> Unfortunately the commit doesn't contain the call chain that
> led to fix.

Ok, I would really appreciate the trace.

If this is really an issue, we should provide a helper in the TTY layer
like tty_schedule_wakeup.

thanks,
-- 
js
suse labs

Re: [PATCH 25/69] TTY: con3215, remove tasklet for tty_wakeup

[Greg KH]

On Tue, Apr 03, 2012 at 09:59:19AM +0200, Jiri Slaby wrote:
> On 04/03/2012 07:42 AM, Heiko Carstens wrote:
> > On Mon, Apr 02, 2012 at 01:54:09PM +0200, Jiri Slaby wrote:
> >> tty_wakeup is safe to be called from all contexts. No need to schedule
> >> a tasklet for that. Let us call it directly like in other drivers.
> >>
> >> And delete the tasklet completely.
> > 
> > Your patch actually reverts Martin's recent commit 656d912537
> > "[S390] 3215 deadlock with tty_wakeup".
> > I'm quite sure the reason for the deadlock still exists.
> > Unfortunately the commit doesn't contain the call chain that
> > led to fix.
> 
> Ok, I would really appreciate the trace.
> 
> If this is really an issue, we should provide a helper in the TTY layer
> like tty_schedule_wakeup.

Jiri, should I not apply this patch?

thanks,

greg k-h

Re: [PATCH 25/69] TTY: con3215, remove tasklet for tty_wakeup

[Jiri Slaby]

On 04/09/2012 08:27 PM, Greg KH wrote:
> On Tue, Apr 03, 2012 at 09:59:19AM +0200, Jiri Slaby wrote:
>> On 04/03/2012 07:42 AM, Heiko Carstens wrote:
>>> On Mon, Apr 02, 2012 at 01:54:09PM +0200, Jiri Slaby wrote:
>>>> tty_wakeup is safe to be called from all contexts. No need to schedule
>>>> a tasklet for that. Let us call it directly like in other drivers.
>>>>
>>>> And delete the tasklet completely.
>>>
>>> Your patch actually reverts Martin's recent commit 656d912537
>>> "[S390] 3215 deadlock with tty_wakeup".
>>> I'm quite sure the reason for the deadlock still exists.
>>> Unfortunately the commit doesn't contain the call chain that
>>> led to fix.
>>
>> Ok, I would really appreciate the trace.
>>
>> If this is really an issue, we should provide a helper in the TTY layer
>> like tty_schedule_wakeup.
> 
> Jiri, should I not apply this patch?

Yes, please skip it until this is sorted out. And also the other con3215
patches if they don't apply cleanly now.

thanks,
-- 
js
suse labs

Re: [PATCH 25/69] TTY: con3215, remove tasklet for tty_wakeup

[Greg KH]

On Mon, Apr 09, 2012 at 08:30:23PM +0200, Jiri Slaby wrote:
> On 04/09/2012 08:27 PM, Greg KH wrote:
> > On Tue, Apr 03, 2012 at 09:59:19AM +0200, Jiri Slaby wrote:
> >> On 04/03/2012 07:42 AM, Heiko Carstens wrote:
> >>> On Mon, Apr 02, 2012 at 01:54:09PM +0200, Jiri Slaby wrote:
> >>>> tty_wakeup is safe to be called from all contexts. No need to schedule
> >>>> a tasklet for that. Let us call it directly like in other drivers.
> >>>>
> >>>> And delete the tasklet completely.
> >>>
> >>> Your patch actually reverts Martin's recent commit 656d912537
> >>> "[S390] 3215 deadlock with tty_wakeup".
> >>> I'm quite sure the reason for the deadlock still exists.
> >>> Unfortunately the commit doesn't contain the call chain that
> >>> led to fix.
> >>
> >> Ok, I would really appreciate the trace.
> >>
> >> If this is really an issue, we should provide a helper in the TTY layer
> >> like tty_schedule_wakeup.
> > 
> > Jiri, should I not apply this patch?
> 
> Yes, please skip it until this is sorted out. And also the other con3215
> patches if they don't apply cleanly now.

Ok, I've not applied patches 25, 26, and 27 in this series, but have
applied all others, thanks.

greg k-h

[PATCH 26/69] TTY: con3215, add tty_port

[Jiri Slaby]

And use flags from that. But first we have to get rid of duplicated
flag names. From now on, for the standard ones that are stored in
tty_port->flags, we use ASYNC_* ones.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
---
 drivers/s390/char/con3215.c |   30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/drivers/s390/char/con3215.c b/drivers/s390/char/con3215.c
index fb195f3..9a76614 100644
--- a/drivers/s390/char/con3215.c
+++ b/drivers/s390/char/con3215.c
@@ -20,6 +20,7 @@
 #include <linux/interrupt.h>
 #include <linux/err.h>
 #include <linux/reboot.h>
+#include <linux/serial.h> /* ASYNC_* flags */
 #include <linux/slab.h>
 #include <asm/ccwdev.h>
 #include <asm/cio.h>
@@ -44,14 +45,11 @@
 #define RAW3215_TIMEOUT	    HZ/10     /* time for delayed output */
 
 #define RAW3215_FIXED	    1	      /* 3215 console device is not be freed */
-#define RAW3215_ACTIVE	    2	      /* set if the device is in use */
 #define RAW3215_WORKING	    4	      /* set if a request is being worked on */
 #define RAW3215_THROTTLED   8	      /* set if reading is disabled */
 #define RAW3215_STOPPED	    16	      /* set if writing is disabled */
-#define RAW3215_CLOSING	    32	      /* set while in close process */
 #define RAW3215_TIMER_RUNS  64	      /* set if the output delay timer is on */
 #define RAW3215_FLUSHING    128	      /* set to flush buffer (no delay) */
-#define RAW3215_FROZEN	    256	      /* set if 3215 is frozen for suspend */
 
 #define TAB_STOP_SIZE	    8	      /* tab stop size */
 
@@ -76,6 +74,7 @@ struct raw3215_req {
 } __attribute__ ((aligned(8)));
 
 struct raw3215_info {
+	struct tty_port port;
 	struct ccw_device *cdev;      /* device for tty driver */
 	spinlock_t *lock;	      /* pointer to irq lock */
 	int flags;		      /* state flags */
@@ -292,7 +291,7 @@ static void raw3215_timeout(unsigned long __data)
 	if (raw->flags & RAW3215_TIMER_RUNS) {
 		del_timer(&raw->timer);
 		raw->flags &= ~RAW3215_TIMER_RUNS;
-		if (!(raw->flags & RAW3215_FROZEN)) {
+		if (!(raw->port.flags & ASYNC_SUSPENDED)) {
 			raw3215_mk_write_req(raw);
 			raw3215_start_io(raw);
 		}
@@ -308,7 +307,8 @@ static void raw3215_timeout(unsigned long __data)
  */
 static inline void raw3215_try_io(struct raw3215_info *raw)
 {
-	if (!(raw->flags & RAW3215_ACTIVE) || (raw->flags & RAW3215_FROZEN))
+	if (!(raw->port.flags & ASYNC_INITIALIZED) ||
+			(raw->port.flags & ASYNC_SUSPENDED))
 		return;
 	if (raw->queued_read != NULL)
 		raw3215_start_io(raw);
@@ -474,7 +474,7 @@ static void raw3215_make_room(struct raw3215_info *raw, unsigned int length)
 		/* While console is frozen for suspend we have no other
 		 * choice but to drop message from the buffer to make
 		 * room for even more messages. */
-		if (raw->flags & RAW3215_FROZEN) {
+		if (raw->port.flags & ASYNC_SUSPENDED) {
 			raw3215_drop_line(raw);
 			continue;
 		}
@@ -596,10 +596,10 @@ static int raw3215_startup(struct raw3215_info *raw)
 {
 	unsigned long flags;
 
-	if (raw->flags & RAW3215_ACTIVE)
+	if (raw->port.flags & ASYNC_INITIALIZED)
 		return 0;
 	raw->line_pos = 0;
-	raw->flags |= RAW3215_ACTIVE;
+	raw->port.flags |= ASYNC_INITIALIZED;
 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
 	raw3215_try_io(raw);
 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
@@ -615,14 +615,15 @@ static void raw3215_shutdown(struct raw3215_info *raw)
 	DECLARE_WAITQUEUE(wait, current);
 	unsigned long flags;
 
-	if (!(raw->flags & RAW3215_ACTIVE) || (raw->flags & RAW3215_FIXED))
+	if (!(raw->port.flags & ASYNC_INITIALIZED) ||
+			(raw->flags & RAW3215_FIXED))
 		return;
 	/* Wait for outstanding requests, then free irq */
 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
 	if ((raw->flags & RAW3215_WORKING) ||
 	    raw->queued_write != NULL ||
 	    raw->queued_read != NULL) {
-		raw->flags |= RAW3215_CLOSING;
+		raw->port.flags |= ASYNC_CLOSING;
 		add_wait_queue(&raw->empty_wait, &wait);
 		set_current_state(TASK_INTERRUPTIBLE);
 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
@@ -630,7 +631,7 @@ static void raw3215_shutdown(struct raw3215_info *raw)
 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
 		remove_wait_queue(&raw->empty_wait, &wait);
 		set_current_state(TASK_RUNNING);
-		raw->flags &= ~(RAW3215_ACTIVE | RAW3215_CLOSING);
+		raw->port.flags &= ~(ASYNC_INITIALIZED | ASYNC_CLOSING);
 	}
 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
 }
@@ -652,6 +653,7 @@ static struct raw3215_info *raw3215_alloc_info(void)
 
 	setup_timer(&info->timer, raw3215_timeout, (unsigned long)info);
 	init_waitqueue_head(&info->empty_wait);
+	tty_port_init(&info->port);
 
 	return info;
 }
@@ -741,7 +743,7 @@ static int raw3215_pm_stop(struct ccw_device *cdev)
 	raw = dev_get_drvdata(&cdev->dev);
 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
-	raw->flags |= RAW3215_FROZEN;
+	raw->port.flags |= ASYNC_SUSPENDED;
 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
 	return 0;
 }
@@ -754,7 +756,7 @@ static int raw3215_pm_start(struct ccw_device *cdev)
 	/* Allow I/O again and flush output buffer. */
 	raw = dev_get_drvdata(&cdev->dev);
 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
-	raw->flags &= ~RAW3215_FROZEN;
+	raw->port.flags &= ~ASYNC_SUSPENDED;
 	raw->flags |= RAW3215_FLUSHING;
 	raw3215_try_io(raw);
 	raw->flags &= ~RAW3215_FLUSHING;
@@ -827,7 +829,7 @@ static void con3215_flush(void)
 	unsigned long flags;
 
 	raw = raw3215[0];  /* console 3215 is the first one */
-	if (raw->flags & RAW3215_FROZEN)
+	if (raw->port.flags & ASYNC_SUSPENDED)
 		/* The console is still frozen for suspend. */
 		if (ccw_device_force_console())
 			/* Forcing didn't work, no panic message .. */
-- 
1.7.9.2

[PATCH 27/69] TTY: con3215, use tty from tty_port

[Jiri Slaby]

Obtain tty_struct only once in ISR and pass it down to
raw3215_next_io. Other than that, we just use the tty with raised
reference. And set it properly in open and close.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
---
 drivers/s390/char/con3215.c |   34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/drivers/s390/char/con3215.c b/drivers/s390/char/con3215.c
index 9a76614..3e01756 100644
--- a/drivers/s390/char/con3215.c
+++ b/drivers/s390/char/con3215.c
@@ -83,7 +83,6 @@ struct raw3215_info {
 	int head;		      /* first free byte in output buffer */
 	int count;		      /* number of bytes in output buffer */
 	int written;		      /* number of bytes in write requests */
-	struct tty_struct *tty;	      /* pointer to tty structure if present */
 	struct raw3215_req *queued_read; /* pointer to queued read requests */
 	struct raw3215_req *queued_write;/* pointer to queued write requests */
 	wait_queue_head_t empty_wait; /* wait queue for flushing */
@@ -333,12 +332,12 @@ static inline void raw3215_try_io(struct raw3215_info *raw)
 /*
  * Try to start the next IO and wake up processes waiting on the tty.
  */
-static void raw3215_next_io(struct raw3215_info *raw)
+static void raw3215_next_io(struct raw3215_info *raw, struct tty_struct *tty)
 {
 	raw3215_mk_write_req(raw);
 	raw3215_try_io(raw);
-	if (raw->tty && RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE)
-		tty_wakeup(raw->tty);
+	if (tty && RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE)
+		tty_wakeup(tty);
 }
 
 /*
@@ -355,10 +354,11 @@ static void raw3215_irq(struct ccw_device *cdev, unsigned long intparm,
 
 	raw = dev_get_drvdata(&cdev->dev);
 	req = (struct raw3215_req *) intparm;
+	tty = tty_port_tty_get(&raw->port);
 	cstat = irb->scsw.cmd.cstat;
 	dstat = irb->scsw.cmd.dstat;
 	if (cstat != 0)
-		raw3215_next_io(raw);
+		raw3215_next_io(raw, tty);
 	if (dstat & 0x01) { /* we got a unit exception */
 		dstat &= ~0x01;	 /* we can ignore it */
 	}
@@ -368,13 +368,13 @@ static void raw3215_irq(struct ccw_device *cdev, unsigned long intparm,
 			break;
 		/* Attention interrupt, someone hit the enter key */
 		raw3215_mk_read_req(raw);
-		raw3215_next_io(raw);
+		raw3215_next_io(raw, tty);
 		break;
 	case 0x08:
 	case 0x0C:
 		/* Channel end interrupt. */
 		if ((raw = req->info) == NULL)
-			return;		     /* That shouldn't happen ... */
+			goto put_tty;	     /* That shouldn't happen ... */
 		if (req->type == RAW3215_READ) {
 			/* store residual count, then wait for device end */
 			req->residual = irb->scsw.cmd.count;
@@ -384,11 +384,10 @@ static void raw3215_irq(struct ccw_device *cdev, unsigned long intparm,
 	case 0x04:
 		/* Device end interrupt. */
 		if ((raw = req->info) == NULL)
-			return;		     /* That shouldn't happen ... */
-		if (req->type == RAW3215_READ && raw->tty != NULL) {
+			goto put_tty;	     /* That shouldn't happen ... */
+		if (req->type == RAW3215_READ && tty != NULL) {
 			unsigned int cchar;
 
-			tty = raw->tty;
 			count = 160 - req->residual;
 			EBCASC(raw->inbuf, count);
 			cchar = ctrlchar_handle(raw->inbuf, count, tty);
@@ -398,7 +397,7 @@ static void raw3215_irq(struct ccw_device *cdev, unsigned long intparm,
 
 			case CTRLCHAR_CTRL:
 				tty_insert_flip_char(tty, cchar, TTY_NORMAL);
-				tty_flip_buffer_push(raw->tty);
+				tty_flip_buffer_push(tty);
 				break;
 
 			case CTRLCHAR_NONE:
@@ -411,7 +410,7 @@ static void raw3215_irq(struct ccw_device *cdev, unsigned long intparm,
 				} else
 					count -= 2;
 				tty_insert_flip_string(tty, raw->inbuf, count);
-				tty_flip_buffer_push(raw->tty);
+				tty_flip_buffer_push(tty);
 				break;
 			}
 		} else if (req->type == RAW3215_WRITE) {
@@ -426,7 +425,7 @@ static void raw3215_irq(struct ccw_device *cdev, unsigned long intparm,
 		    raw->queued_read == NULL) {
 			wake_up_interruptible(&raw->empty_wait);
 		}
-		raw3215_next_io(raw);
+		raw3215_next_io(raw, tty);
 		break;
 	default:
 		/* Strange interrupt, I'll do my best to clean up */
@@ -438,9 +437,10 @@ static void raw3215_irq(struct ccw_device *cdev, unsigned long intparm,
 			raw->flags &= ~RAW3215_WORKING;
 			raw3215_free_req(req);
 		}
-		raw3215_next_io(raw);
+		raw3215_next_io(raw, tty);
 	}
-	return;
+put_tty:
+	tty_kref_put(tty);
 }
 
 /*
@@ -935,7 +935,7 @@ static int tty3215_open(struct tty_struct *tty, struct file * filp)
 		return -ENODEV;
 
 	tty->driver_data = raw;
-	raw->tty = tty;
+	tty_port_tty_set(&raw->port, tty);
 
 	tty->low_latency = 0;  /* don't use bottom half for pushing chars */
 	/*
@@ -965,7 +965,7 @@ static void tty3215_close(struct tty_struct *tty, struct file * filp)
 	/* Shutdown the terminal */
 	raw3215_shutdown(raw);
 	tty->closing = 0;
-	raw->tty = NULL;
+	tty_port_tty_set(&raw->port, NULL);
 }
 
 /*
-- 
1.7.9.2

[PATCH 28/69] TTY: sclp_tty, add tty_port

[Jiri Slaby]

tty_port will hold tty buffers in the future. So we need to have it
even here. The only needed member here is tty, so let us store it in
the structure now.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
---
 drivers/s390/char/sclp_tty.c |   33 +++++++++++++++++++--------------
 1 file changed, 19 insertions(+), 14 deletions(-)

diff --git a/drivers/s390/char/sclp_tty.c b/drivers/s390/char/sclp_tty.c
index 40a9d69..e66a75b 100644
--- a/drivers/s390/char/sclp_tty.c
+++ b/drivers/s390/char/sclp_tty.c
@@ -48,7 +48,7 @@ static struct sclp_buffer *sclp_ttybuf;
 /* Timer for delayed output of console messages. */
 static struct timer_list sclp_tty_timer;
 
-static struct tty_struct *sclp_tty;
+static struct tty_port sclp_port;
 static unsigned char sclp_tty_chars[SCLP_TTY_BUF_SIZE];
 static unsigned short int sclp_tty_chars_count;
 
@@ -64,7 +64,7 @@ static int sclp_tty_columns = 80;
 static int
 sclp_tty_open(struct tty_struct *tty, struct file *filp)
 {
-	sclp_tty = tty;
+	tty_port_tty_set(&sclp_port, tty);
 	tty->driver_data = NULL;
 	tty->low_latency = 0;
 	return 0;
@@ -76,7 +76,7 @@ sclp_tty_close(struct tty_struct *tty, struct file *filp)
 {
 	if (tty->count > 1)
 		return;
-	sclp_tty = NULL;
+	tty_port_tty_set(&sclp_port, NULL);
 }
 
 /*
@@ -108,6 +108,7 @@ sclp_tty_write_room (struct tty_struct *tty)
 static void
 sclp_ttybuf_callback(struct sclp_buffer *buffer, int rc)
 {
+	struct tty_struct *tty;
 	unsigned long flags;
 	void *page;
 
@@ -126,8 +127,10 @@ sclp_ttybuf_callback(struct sclp_buffer *buffer, int rc)
 		spin_unlock_irqrestore(&sclp_tty_lock, flags);
 	} while (buffer && sclp_emit_buffer(buffer, sclp_ttybuf_callback));
 	/* check if the tty needs a wake up call */
-	if (sclp_tty != NULL) {
-		tty_wakeup(sclp_tty);
+	tty = tty_port_tty_get(&sclp_port);
+	if (tty != NULL) {
+		tty_wakeup(tty);
+		tty_kref_put(tty);
 	}
 }
 
@@ -326,21 +329,22 @@ sclp_tty_flush_buffer(struct tty_struct *tty)
 static void
 sclp_tty_input(unsigned char* buf, unsigned int count)
 {
+	struct tty_struct *tty = tty_port_tty_get(&sclp_port);
 	unsigned int cchar;
 
 	/*
 	 * If this tty driver is currently closed
 	 * then throw the received input away.
 	 */
-	if (sclp_tty == NULL)
+	if (tty == NULL)
 		return;
-	cchar = ctrlchar_handle(buf, count, sclp_tty);
+	cchar = ctrlchar_handle(buf, count, tty);
 	switch (cchar & CTRLCHAR_MASK) {
 	case CTRLCHAR_SYSRQ:
 		break;
 	case CTRLCHAR_CTRL:
-		tty_insert_flip_char(sclp_tty, cchar, TTY_NORMAL);
-		tty_flip_buffer_push(sclp_tty);
+		tty_insert_flip_char(tty, cchar, TTY_NORMAL);
+		tty_flip_buffer_push(tty);
 		break;
 	case CTRLCHAR_NONE:
 		/* send (normal) input to line discipline */
@@ -348,13 +352,14 @@ sclp_tty_input(unsigned char* buf, unsigned int count)
 		    (strncmp((const char *) buf + count - 2, "^n", 2) &&
 		     strncmp((const char *) buf + count - 2, "\252n", 2))) {
 			/* add the auto \n */
-			tty_insert_flip_string(sclp_tty, buf, count);
-			tty_insert_flip_char(sclp_tty, '\n', TTY_NORMAL);
+			tty_insert_flip_string(tty, buf, count);
+			tty_insert_flip_char(tty, '\n', TTY_NORMAL);
 		} else
-			tty_insert_flip_string(sclp_tty, buf, count - 2);
-		tty_flip_buffer_push(sclp_tty);
+			tty_insert_flip_string(tty, buf, count - 2);
+		tty_flip_buffer_push(tty);
 		break;
 	}
+	tty_kref_put(tty);
 }
 
 /*
@@ -543,7 +548,7 @@ sclp_tty_init(void)
 		sclp_tty_tolower = 1;
 	}
 	sclp_tty_chars_count = 0;
-	sclp_tty = NULL;
+	tty_port_init(&sclp_port);
 
 	rc = sclp_register(&sclp_input_event);
 	if (rc) {
-- 
1.7.9.2

[PATCH 29/69] TTY: sclp_vt220, add tty_port

[Jiri Slaby]

tty_port will hold tty buffers in the future. So we need to have it
even here. The only needed member here is tty, so let us store it in
the structure now.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
---
 drivers/s390/char/sclp_vt220.c |   24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/drivers/s390/char/sclp_vt220.c b/drivers/s390/char/sclp_vt220.c
index b635472..25cf2e8 100644
--- a/drivers/s390/char/sclp_vt220.c
+++ b/drivers/s390/char/sclp_vt220.c
@@ -56,8 +56,7 @@ struct sclp_vt220_sccb {
 /* Structures and data needed to register tty driver */
 static struct tty_driver *sclp_vt220_driver;
 
-/* The tty_struct that the kernel associated with us */
-static struct tty_struct *sclp_vt220_tty;
+static struct tty_port sclp_vt220_port;
 
 /* Lock to protect internal data from concurrent access */
 static spinlock_t sclp_vt220_lock;
@@ -116,6 +115,7 @@ static struct sclp_register sclp_vt220_register = {
 static void
 sclp_vt220_process_queue(struct sclp_vt220_request *request)
 {
+	struct tty_struct *tty;
 	unsigned long flags;
 	void *page;
 
@@ -141,8 +141,10 @@ sclp_vt220_process_queue(struct sclp_vt220_request *request)
 	if (request == NULL && sclp_vt220_flush_later)
 		sclp_vt220_emit_current();
 	/* Check if the tty needs a wake up call */
-	if (sclp_vt220_tty != NULL) {
-		tty_wakeup(sclp_vt220_tty);
+	tty = tty_port_tty_get(&sclp_vt220_port);
+	if (tty) {
+		tty_wakeup(tty);
+		tty_kref_put(tty);
 	}
 }
 
@@ -460,11 +462,12 @@ sclp_vt220_write(struct tty_struct *tty, const unsigned char *buf, int count)
 static void
 sclp_vt220_receiver_fn(struct evbuf_header *evbuf)
 {
+	struct tty_struct *tty = tty_port_tty_get(&sclp_vt220_port);
 	char *buffer;
 	unsigned int count;
 
 	/* Ignore input if device is not open */
-	if (sclp_vt220_tty == NULL)
+	if (tty == NULL)
 		return;
 
 	buffer = (char *) ((addr_t) evbuf + sizeof(struct evbuf_header));
@@ -478,10 +481,11 @@ sclp_vt220_receiver_fn(struct evbuf_header *evbuf)
 		/* Send input to line discipline */
 		buffer++;
 		count--;
-		tty_insert_flip_string(sclp_vt220_tty, buffer, count);
-		tty_flip_buffer_push(sclp_vt220_tty);
+		tty_insert_flip_string(tty, buffer, count);
+		tty_flip_buffer_push(tty);
 		break;
 	}
+	tty_kref_put(tty);
 }
 
 /*
@@ -491,7 +495,7 @@ static int
 sclp_vt220_open(struct tty_struct *tty, struct file *filp)
 {
 	if (tty->count == 1) {
-		sclp_vt220_tty = tty;
+		tty_port_tty_set(&sclp_vt220_port, tty);
 		tty->driver_data = kmalloc(SCLP_VT220_BUF_SIZE, GFP_KERNEL);
 		if (tty->driver_data == NULL)
 			return -ENOMEM;
@@ -511,7 +515,7 @@ static void
 sclp_vt220_close(struct tty_struct *tty, struct file *filp)
 {
 	if (tty->count == 1) {
-		sclp_vt220_tty = NULL;
+		tty_port_tty_set(&sclp_vt220_port, NULL);
 		kfree(tty->driver_data);
 		tty->driver_data = NULL;
 	}
@@ -635,9 +639,9 @@ static int __init __sclp_vt220_init(int num_pages)
 	INIT_LIST_HEAD(&sclp_vt220_empty);
 	INIT_LIST_HEAD(&sclp_vt220_outqueue);
 	init_timer(&sclp_vt220_timer);
+	tty_port_init(&sclp_vt220_port);
 	sclp_vt220_current_request = NULL;
 	sclp_vt220_buffered_chars = 0;
-	sclp_vt220_tty = NULL;
 	sclp_vt220_flush_later = 0;
 
 	/* Allocate pages for output buffering */
-- 
1.7.9.2

[PATCH 30/69] TTY: sclp_vt220, remove unused allocation

[Jiri Slaby]

80 bytes which are allocated in tty->ops->open and assigned to
tty->driver_data are never used. Remove that.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
---
 drivers/s390/char/sclp_vt220.c |    9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/s390/char/sclp_vt220.c b/drivers/s390/char/sclp_vt220.c
index 25cf2e8..edfc0fd 100644
--- a/drivers/s390/char/sclp_vt220.c
+++ b/drivers/s390/char/sclp_vt220.c
@@ -34,7 +34,6 @@
 #define SCLP_VT220_DEVICE_NAME		"ttysclp"
 #define SCLP_VT220_CONSOLE_NAME		"ttyS"
 #define SCLP_VT220_CONSOLE_INDEX	1	/* console=ttyS1 */
-#define SCLP_VT220_BUF_SIZE		80
 
 /* Representation of a single write request */
 struct sclp_vt220_request {
@@ -496,9 +495,6 @@ sclp_vt220_open(struct tty_struct *tty, struct file *filp)
 {
 	if (tty->count == 1) {
 		tty_port_tty_set(&sclp_vt220_port, tty);
-		tty->driver_data = kmalloc(SCLP_VT220_BUF_SIZE, GFP_KERNEL);
-		if (tty->driver_data == NULL)
-			return -ENOMEM;
 		tty->low_latency = 0;
 		if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
 			tty->winsize.ws_row = 24;
@@ -514,11 +510,8 @@ sclp_vt220_open(struct tty_struct *tty, struct file *filp)
 static void
 sclp_vt220_close(struct tty_struct *tty, struct file *filp)
 {
-	if (tty->count == 1) {
+	if (tty->count == 1)
 		tty_port_tty_set(&sclp_vt220_port, NULL);
-		kfree(tty->driver_data);
-		tty->driver_data = NULL;
-	}
 }
 
 /*
-- 
1.7.9.2

[PATCH 31/69] TTY: tty3270, move initialization to allocation

[Jiri Slaby]

Let us initialize all the tty3270's members at the place where the
structure is allocated.

It cleans up tty->ops->open a bit.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
---
 drivers/s390/char/tty3270.c |   20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/s390/char/tty3270.c b/drivers/s390/char/tty3270.c
index b43445a..f3837da 100644
--- a/drivers/s390/char/tty3270.c
+++ b/drivers/s390/char/tty3270.c
@@ -690,6 +690,16 @@ tty3270_alloc_view(void)
 	if (!tp->freemem_pages)
 		goto out_tp;
 	INIT_LIST_HEAD(&tp->freemem);
+	INIT_LIST_HEAD(&tp->lines);
+	INIT_LIST_HEAD(&tp->update);
+	INIT_LIST_HEAD(&tp->rcl_lines);
+	tp->rcl_max = 20;
+	setup_timer(&tp->timer, (void (*)(unsigned long)) tty3270_update,
+		    (unsigned long) tp);
+	tasklet_init(&tp->readlet,
+		     (void (*)(unsigned long)) tty3270_read_tasklet,
+		     (unsigned long) tp->read);
+
 	for (pages = 0; pages < TTY3270_STRING_PAGES; pages++) {
 		tp->freemem_pages[pages] = (void *)
 			__get_free_pages(GFP_KERNEL|GFP_DMA, 0);
@@ -879,16 +889,6 @@ tty3270_open(struct tty_struct *tty, struct file * filp)
 	if (IS_ERR(tp))
 		return PTR_ERR(tp);
 
-	INIT_LIST_HEAD(&tp->lines);
-	INIT_LIST_HEAD(&tp->update);
-	INIT_LIST_HEAD(&tp->rcl_lines);
-	tp->rcl_max = 20;
-	setup_timer(&tp->timer, (void (*)(unsigned long)) tty3270_update,
-		    (unsigned long) tp);
-	tasklet_init(&tp->readlet, 
-		     (void (*)(unsigned long)) tty3270_read_tasklet,
-		     (unsigned long) tp->read);
-
 	rc = raw3270_add_view(&tp->view, &tty3270_fn,
 			      tty->index + RAW3270_FIRSTMINOR);
 	if (rc) {
-- 
1.7.9.2

[PATCH 32/69] TTY: tty3270, get rid of ugly aliasing

[Jiri Slaby]

Blah, do not assume that raw3270_view is at the beginning of tty3270.
Use proper types and container_of wherever needed.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
---
 drivers/s390/char/tty3270.c |   42 +++++++++++++++++++-----------------------
 1 file changed, 19 insertions(+), 23 deletions(-)

diff --git a/drivers/s390/char/tty3270.c b/drivers/s390/char/tty3270.c
index f3837da..bb1514a 100644
--- a/drivers/s390/char/tty3270.c
+++ b/drivers/s390/char/tty3270.c
@@ -324,9 +324,8 @@ tty3270_blank_line(struct tty3270 *tp)
 static void
 tty3270_write_callback(struct raw3270_request *rq, void *data)
 {
-	struct tty3270 *tp;
+	struct tty3270 *tp = container_of(rq->view, struct tty3270, view);
 
-	tp = (struct tty3270 *) rq->view;
 	if (rq->rc != 0) {
 		/* Write wasn't successful. Refresh all. */
 		tp->update_flags = TTY_UPDATE_ALL;
@@ -537,11 +536,10 @@ static void
 tty3270_read_tasklet(struct raw3270_request *rrq)
 {
 	static char kreset_data = TW_KR;
-	struct tty3270 *tp;
+	struct tty3270 *tp = container_of(rrq->view, struct tty3270, view);
 	char *input;
 	int len;
 
-	tp = (struct tty3270 *) rrq->view;
 	spin_lock_bh(&tp->view.lock);
 	/*
 	 * Two AID keys are special: For 0x7d (enter) the input line
@@ -596,9 +594,10 @@ tty3270_read_tasklet(struct raw3270_request *rrq)
 static void
 tty3270_read_callback(struct raw3270_request *rq, void *data)
 {
+	struct tty3270 *tp = container_of(rq->view, struct tty3270, view);
 	raw3270_get_view(rq->view);
 	/* Schedule tasklet to pass input to tty. */
-	tasklet_schedule(&((struct tty3270 *) rq->view)->readlet);
+	tasklet_schedule(&tp->readlet);
 }
 
 /*
@@ -635,9 +634,8 @@ tty3270_issue_read(struct tty3270 *tp, int lock)
 static int
 tty3270_activate(struct raw3270_view *view)
 {
-	struct tty3270 *tp;
+	struct tty3270 *tp = container_of(view, struct tty3270, view);
 
-	tp = (struct tty3270 *) view;
 	tp->update_flags = TTY_UPDATE_ALL;
 	tty3270_set_timer(tp, 1);
 	return 0;
@@ -646,9 +644,8 @@ tty3270_activate(struct raw3270_view *view)
 static void
 tty3270_deactivate(struct raw3270_view *view)
 {
-	struct tty3270 *tp;
+	struct tty3270 *tp = container_of(view, struct tty3270, view);
 
-	tp = (struct tty3270 *) view;
 	del_timer(&tp->timer);
 }
 
@@ -804,10 +801,9 @@ tty3270_free_screen(struct tty3270 *tp)
 static void
 tty3270_release(struct raw3270_view *view)
 {
-	struct tty3270 *tp;
+	struct tty3270 *tp = container_of(view, struct tty3270, view);
 	struct tty_struct *tty;
 
-	tp = (struct tty3270 *) view;
 	tty = tp->tty;
 	if (tty) {
 		tty->driver_data = NULL;
@@ -823,8 +819,9 @@ tty3270_release(struct raw3270_view *view)
 static void
 tty3270_free(struct raw3270_view *view)
 {
-	tty3270_free_screen((struct tty3270 *) view);
-	tty3270_free_view((struct tty3270 *) view);
+	struct tty3270 *tp = container_of(view, struct tty3270, view);
+	tty3270_free_screen(tp);
+	tty3270_free_view(tp);
 }
 
 /*
@@ -833,14 +830,13 @@ tty3270_free(struct raw3270_view *view)
 static void
 tty3270_del_views(void)
 {
-	struct tty3270 *tp;
 	int i;
 
 	for (i = 0; i < tty3270_max_index; i++) {
-		tp = (struct tty3270 *)
+		struct raw3270_view *view =
 			raw3270_find_view(&tty3270_fn, i + RAW3270_FIRSTMINOR);
-		if (!IS_ERR(tp))
-			raw3270_del_view(&tp->view);
+		if (!IS_ERR(view))
+			raw3270_del_view(view);
 	}
 }
 
@@ -858,16 +854,17 @@ static struct raw3270_fn tty3270_fn = {
 static int
 tty3270_open(struct tty_struct *tty, struct file * filp)
 {
+	struct raw3270_view *view;
 	struct tty3270 *tp;
 	int i, rc;
 
 	if (tty->count > 1)
 		return 0;
 	/* Check if the tty3270 is already there. */
-	tp = (struct tty3270 *)
-		raw3270_find_view(&tty3270_fn,
+	view = raw3270_find_view(&tty3270_fn,
 				  tty->index + RAW3270_FIRSTMINOR);
-	if (!IS_ERR(tp)) {
+	if (!IS_ERR(view)) {
+		tp = container_of(view, struct tty3270, view);
 		tty->driver_data = tp;
 		tty->winsize.ws_row = tp->view.rows - 2;
 		tty->winsize.ws_col = tp->view.cols;
@@ -881,7 +878,7 @@ tty3270_open(struct tty_struct *tty, struct file * filp)
 		tty3270_max_index = tty->index + 1;
 
 	/* Quick exit if there is no device for tty->index. */
-	if (PTR_ERR(tp) == -ENODEV)
+	if (PTR_ERR(view) == -ENODEV)
 		return -ENODEV;
 
 	/* Allocate tty3270 structure on first open. */
@@ -935,11 +932,10 @@ tty3270_open(struct tty_struct *tty, struct file * filp)
 static void
 tty3270_close(struct tty_struct *tty, struct file * filp)
 {
-	struct tty3270 *tp;
+	struct tty3270 *tp = tty->driver_data;
 
 	if (tty->count > 1)
 		return;
-	tp = (struct tty3270 *) tty->driver_data;
 	if (tp) {
 		tty->driver_data = NULL;
 		tp->tty = tp->kbd->tty = NULL;
-- 
1.7.9.2

[PATCH 33/69] TTY: tty3270, push tty down to tty3270_do_write

[Jiri Slaby]

So that we do not need to access tp->tty there. It is going away.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
---
 drivers/s390/char/tty3270.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/s390/char/tty3270.c b/drivers/s390/char/tty3270.c
index bb1514a..1f4aff7 100644
--- a/drivers/s390/char/tty3270.c
+++ b/drivers/s390/char/tty3270.c
@@ -1509,12 +1509,13 @@ tty3270_escape_sequence(struct tty3270 *tp, char ch)
  * String write routine for 3270 ttys
  */
 static void
-tty3270_do_write(struct tty3270 *tp, const unsigned char *buf, int count)
+tty3270_do_write(struct tty3270 *tp, struct tty_struct *tty,
+		const unsigned char *buf, int count)
 {
 	int i_msg, i;
 
 	spin_lock_bh(&tp->view.lock);
-	for (i_msg = 0; !tp->tty->stopped && i_msg < count; i_msg++) {
+	for (i_msg = 0; !tty->stopped && i_msg < count; i_msg++) {
 		if (tp->esc_state != 0) {
 			/* Continue escape sequence. */
 			tty3270_escape_sequence(tp, buf[i_msg]);
@@ -1591,10 +1592,10 @@ tty3270_write(struct tty_struct * tty,
 	if (!tp)
 		return 0;
 	if (tp->char_count > 0) {
-		tty3270_do_write(tp, tp->char_buf, tp->char_count);
+		tty3270_do_write(tp, tty, tp->char_buf, tp->char_count);
 		tp->char_count = 0;
 	}
-	tty3270_do_write(tp, buf, count);
+	tty3270_do_write(tp, tty, buf, count);
 	return count;
 }
 
@@ -1625,7 +1626,7 @@ tty3270_flush_chars(struct tty_struct *tty)
 	if (!tp)
 		return;
 	if (tp->char_count > 0) {
-		tty3270_do_write(tp, tp->char_buf, tp->char_count);
+		tty3270_do_write(tp, tty, tp->char_buf, tp->char_count);
 		tp->char_count = 0;
 	}
 }
-- 
1.7.9.2

[PATCH 34/69] TTY: tty3270, add tty_port

[Jiri Slaby]

And use tty from that. This means, we convert most of the users to
accept tty_port instead. This is not racy and ensures the tty to be
properly refcounted.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
---
 drivers/s390/char/keyboard.c |   30 ++++++++++++++------------
 drivers/s390/char/keyboard.h |   14 +++++++++---
 drivers/s390/char/tty3270.c  |   48 ++++++++++++++++++------------------------
 3 files changed, 49 insertions(+), 43 deletions(-)

diff --git a/drivers/s390/char/keyboard.c b/drivers/s390/char/keyboard.c
index 8065881..7ef9cfd 100644
--- a/drivers/s390/char/keyboard.c
+++ b/drivers/s390/char/keyboard.c
@@ -199,7 +199,7 @@ handle_diacr(struct kbd_data *kbd, unsigned int ch)
 	if (ch == ' ' || ch == d)
 		return d;
 
-	kbd_put_queue(kbd->tty, d);
+	kbd_put_queue(kbd->port, d);
 	return ch;
 }
 
@@ -221,7 +221,7 @@ k_self(struct kbd_data *kbd, unsigned char value)
 {
 	if (kbd->diacr)
 		value = handle_diacr(kbd, value);
-	kbd_put_queue(kbd->tty, value);
+	kbd_put_queue(kbd->port, value);
 }
 
 /*
@@ -239,7 +239,7 @@ static void
 k_fn(struct kbd_data *kbd, unsigned char value)
 {
 	if (kbd->func_table[value])
-		kbd_puts_queue(kbd->tty, kbd->func_table[value]);
+		kbd_puts_queue(kbd->port, kbd->func_table[value]);
 }
 
 static void
@@ -257,20 +257,20 @@ k_spec(struct kbd_data *kbd, unsigned char value)
  * but we need only 16 bits here
  */
 static void
-to_utf8(struct tty_struct *tty, ushort c) 
+to_utf8(struct tty_port *port, ushort c)
 {
 	if (c < 0x80)
 		/*  0******* */
-		kbd_put_queue(tty, c);
+		kbd_put_queue(port, c);
 	else if (c < 0x800) {
 		/* 110***** 10****** */
-		kbd_put_queue(tty, 0xc0 | (c >> 6));
-		kbd_put_queue(tty, 0x80 | (c & 0x3f));
+		kbd_put_queue(port, 0xc0 | (c >> 6));
+		kbd_put_queue(port, 0x80 | (c & 0x3f));
 	} else {
 		/* 1110**** 10****** 10****** */
-		kbd_put_queue(tty, 0xe0 | (c >> 12));
-		kbd_put_queue(tty, 0x80 | ((c >> 6) & 0x3f));
-		kbd_put_queue(tty, 0x80 | (c & 0x3f));
+		kbd_put_queue(port, 0xe0 | (c >> 12));
+		kbd_put_queue(port, 0x80 | ((c >> 6) & 0x3f));
+		kbd_put_queue(port, 0x80 | (c & 0x3f));
 	}
 }
 
@@ -283,7 +283,7 @@ kbd_keycode(struct kbd_data *kbd, unsigned int keycode)
 	unsigned short keysym;
 	unsigned char type, value;
 
-	if (!kbd || !kbd->tty)
+	if (!kbd)
 		return;
 
 	if (keycode >= 384)
@@ -323,7 +323,7 @@ kbd_keycode(struct kbd_data *kbd, unsigned int keycode)
 #endif
 		(*k_handler[type])(kbd, value);
 	} else
-		to_utf8(kbd->tty, keysym);
+		to_utf8(kbd->port, keysym);
 }
 
 /*
@@ -457,6 +457,7 @@ do_kdgkb_ioctl(struct kbd_data *kbd, struct kbsentry __user *u_kbs,
 
 int kbd_ioctl(struct kbd_data *kbd, unsigned int cmd, unsigned long arg)
 {
+	struct tty_struct *tty;
 	void __user *argp;
 	unsigned int ct;
 	int perm;
@@ -467,7 +468,10 @@ int kbd_ioctl(struct kbd_data *kbd, unsigned int cmd, unsigned long arg)
 	 * To have permissions to do most of the vt ioctls, we either have
 	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
 	 */
-	perm = current->signal->tty == kbd->tty || capable(CAP_SYS_TTY_CONFIG);
+	tty = tty_port_tty_get(kbd->port);
+	/* FIXME this test is pretty racy */
+	perm = current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG);
+	tty_kref_put(tty);
 	switch (cmd) {
 	case KDGKBTYPE:
 		return put_user(KB_101, (char __user *)argp);
diff --git a/drivers/s390/char/keyboard.h b/drivers/s390/char/keyboard.h
index 7e736aa..f682f4e 100644
--- a/drivers/s390/char/keyboard.h
+++ b/drivers/s390/char/keyboard.h
@@ -21,7 +21,7 @@ typedef void (fn_handler_fn)(struct kbd_data *);
  */
 
 struct kbd_data {
-	struct tty_struct *tty;
+	struct tty_port *port;
 	unsigned short **key_maps;
 	char **func_table;
 	fn_handler_fn **fn_handler;
@@ -42,16 +42,24 @@ int kbd_ioctl(struct kbd_data *, unsigned int, unsigned long);
  * Helper Functions.
  */
 static inline void
-kbd_put_queue(struct tty_struct *tty, int ch)
+kbd_put_queue(struct tty_port *port, int ch)
 {
+	struct tty_struct *tty = tty_port_tty_get(port);
+	if (!tty)
+		return;
 	tty_insert_flip_char(tty, ch, 0);
 	tty_schedule_flip(tty);
+	tty_kref_put(tty);
 }
 
 static inline void
-kbd_puts_queue(struct tty_struct *tty, char *cp)
+kbd_puts_queue(struct tty_port *port, char *cp)
 {
+	struct tty_struct *tty = tty_port_tty_get(port);
+	if (!tty)
+		return;
 	while (*cp)
 		tty_insert_flip_char(tty, *cp++, 0);
 	tty_schedule_flip(tty);
+	tty_kref_put(tty);
 }
diff --git a/drivers/s390/char/tty3270.c b/drivers/s390/char/tty3270.c
index 1f4aff7..10ec690 100644
--- a/drivers/s390/char/tty3270.c
+++ b/drivers/s390/char/tty3270.c
@@ -61,7 +61,7 @@ struct tty3270_line {
  */
 struct tty3270 {
 	struct raw3270_view view;
-	struct tty_struct *tty;		/* Pointer to tty structure */
+	struct tty_port port;
 	void **freemem_pages;		/* Array of pages used for freemem. */
 	struct list_head freemem;	/* List of free memory for strings. */
 
@@ -449,10 +449,9 @@ tty3270_rcl_add(struct tty3270 *tp, char *input, int len)
 static void
 tty3270_rcl_backward(struct kbd_data *kbd)
 {
-	struct tty3270 *tp;
+	struct tty3270 *tp = container_of(kbd->port, struct tty3270, port);
 	struct string *s;
 
-	tp = kbd->tty->driver_data;
 	spin_lock_bh(&tp->view.lock);
 	if (tp->inattr == TF_INPUT) {
 		if (tp->rcl_walk && tp->rcl_walk->prev != &tp->rcl_lines)
@@ -477,9 +476,8 @@ tty3270_rcl_backward(struct kbd_data *kbd)
 static void
 tty3270_exit_tty(struct kbd_data *kbd)
 {
-	struct tty3270 *tp;
+	struct tty3270 *tp = container_of(kbd->port, struct tty3270, port);
 
-	tp = kbd->tty->driver_data;
 	raw3270_deactivate_view(&tp->view);
 }
 
@@ -489,10 +487,9 @@ tty3270_exit_tty(struct kbd_data *kbd)
 static void
 tty3270_scroll_forward(struct kbd_data *kbd)
 {
-	struct tty3270 *tp;
+	struct tty3270 *tp = container_of(kbd->port, struct tty3270, port);
 	int nr_up;
 
-	tp = kbd->tty->driver_data;
 	spin_lock_bh(&tp->view.lock);
 	nr_up = tp->nr_up - tp->view.rows + 2;
 	if (nr_up < 0)
@@ -512,10 +509,9 @@ tty3270_scroll_forward(struct kbd_data *kbd)
 static void
 tty3270_scroll_backward(struct kbd_data *kbd)
 {
-	struct tty3270 *tp;
+	struct tty3270 *tp = container_of(kbd->port, struct tty3270, port);
 	int nr_up;
 
-	tp = kbd->tty->driver_data;
 	spin_lock_bh(&tp->view.lock);
 	nr_up = tp->nr_up + tp->view.rows - 2;
 	if (nr_up + tp->view.rows - 2 > tp->nr_lines)
@@ -575,13 +571,10 @@ tty3270_read_tasklet(struct raw3270_request *rrq)
 	raw3270_request_add_data(tp->kreset, &kreset_data, 1);
 	raw3270_start(&tp->view, tp->kreset);
 
-	/* Emit input string. */
-	if (tp->tty) {
-		while (len-- > 0)
-			kbd_keycode(tp->kbd, *input++);
-		/* Emit keycode for AID byte. */
-		kbd_keycode(tp->kbd, 256 + tp->input->string[0]);
-	}
+	while (len-- > 0)
+		kbd_keycode(tp->kbd, *input++);
+	/* Emit keycode for AID byte. */
+	kbd_keycode(tp->kbd, 256 + tp->input->string[0]);
 
 	raw3270_request_reset(rrq);
 	xchg(&tp->read, rrq);
@@ -691,6 +684,7 @@ tty3270_alloc_view(void)
 	INIT_LIST_HEAD(&tp->update);
 	INIT_LIST_HEAD(&tp->rcl_lines);
 	tp->rcl_max = 20;
+	tty_port_init(&tp->port);
 	setup_timer(&tp->timer, (void (*)(unsigned long)) tty3270_update,
 		    (unsigned long) tp);
 	tasklet_init(&tp->readlet,
@@ -802,14 +796,14 @@ static void
 tty3270_release(struct raw3270_view *view)
 {
 	struct tty3270 *tp = container_of(view, struct tty3270, view);
-	struct tty_struct *tty;
+	struct tty_struct *tty = tty_port_tty_get(&tp->port);
 
-	tty = tp->tty;
 	if (tty) {
 		tty->driver_data = NULL;
-		tp->tty = tp->kbd->tty = NULL;
+		tty_port_tty_set(&tp->port, NULL);
 		tty_hangup(tty);
 		raw3270_put_view(&tp->view);
+		tty_kref_put(tty);
 	}
 }
 
@@ -869,8 +863,8 @@ tty3270_open(struct tty_struct *tty, struct file * filp)
 		tty->winsize.ws_row = tp->view.rows - 2;
 		tty->winsize.ws_col = tp->view.cols;
 		tty->low_latency = 0;
-		tp->tty = tty;
-		tp->kbd->tty = tty;
+		/* why to reassign? */
+		tty_port_tty_set(&tp->port, tty);
 		tp->inattr = TF_INPUT;
 		return 0;
 	}
@@ -900,7 +894,7 @@ tty3270_open(struct tty_struct *tty, struct file * filp)
 		return rc;
 	}
 
-	tp->tty = tty;
+	tty_port_tty_set(&tp->port, tty);
 	tty->low_latency = 0;
 	tty->driver_data = tp;
 	tty->winsize.ws_row = tp->view.rows - 2;
@@ -914,7 +908,7 @@ tty3270_open(struct tty_struct *tty, struct file * filp)
 	for (i = 0; i < tp->view.rows - 2; i++)
 		tty3270_blank_line(tp);
 
-	tp->kbd->tty = tty;
+	tp->kbd->port = &tp->port;
 	tp->kbd->fn_handler[KVAL(K_INCRCONSOLE)] = tty3270_exit_tty;
 	tp->kbd->fn_handler[KVAL(K_SCROLLBACK)] = tty3270_scroll_backward;
 	tp->kbd->fn_handler[KVAL(K_SCROLLFORW)] = tty3270_scroll_forward;
@@ -938,7 +932,7 @@ tty3270_close(struct tty_struct *tty, struct file * filp)
 		return;
 	if (tp) {
 		tty->driver_data = NULL;
-		tp->tty = tp->kbd->tty = NULL;
+		tty_port_tty_set(&tp->port, NULL);
 		raw3270_put_view(&tp->view);
 	}
 }
@@ -1387,7 +1381,7 @@ tty3270_escape_sequence(struct tty3270 *tp, char ch)
 			tty3270_lf(tp);
 			break;
 		case 'Z':		/* Respond ID. */
-			kbd_puts_queue(tp->tty, "\033[?6c");
+			kbd_puts_queue(&tp->port, "\033[?6c");
 			break;
 		case '7':		/* Save cursor position. */
 			tp->saved_cx = tp->cx;
@@ -1433,11 +1427,11 @@ tty3270_escape_sequence(struct tty3270 *tp, char ch)
 	tp->esc_state = ESnormal;
 	if (ch == 'n' && !tp->esc_ques) {
 		if (tp->esc_par[0] == 5)		/* Status report. */
-			kbd_puts_queue(tp->tty, "\033[0n");
+			kbd_puts_queue(&tp->port, "\033[0n");
 		else if (tp->esc_par[0] == 6) {	/* Cursor report. */
 			char buf[40];
 			sprintf(buf, "\033[%d;%dR", tp->cy + 1, tp->cx + 1);
-			kbd_puts_queue(tp->tty, buf);
+			kbd_puts_queue(&tp->port, buf);
 		}
 		return;
 	}
-- 
1.7.9.2