[PATCH 2/3] TTY: con3215, add tty_port

[PATCH 2/3] 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 7e30f85..f7bc23b 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 */
@@ -293,7 +292,7 @@ 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);
 		}
@@ -309,7 +308,8 @@ 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);
@@ -484,7 +484,7 @@ 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;
 		}
@@ -606,10 +606,10 @@ 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);
@@ -625,14 +625,15 @@ 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);
@@ -640,7 +641,7 @@ 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);
 }
@@ -663,6 +664,7 @@ 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);
+	tty_port_init(&info->port);
 
 	return info;
 }
@@ -752,7 +754,7 @@ 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;
 }
@@ -765,7 +767,7 @@ 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;
@@ -838,7 +840,7 @@ 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 3/3] 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 |   32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/drivers/s390/char/con3215.c b/drivers/s390/char/con3215.c
index f7bc23b..e928e04 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 */
 	struct tasklet_struct tlet;   /* tasklet to invoke tty_wakeup */
@@ -343,11 +342,11 @@ static void raw3215_wakeup(unsigned long data)
 /*
  * 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)
+	if (tty && RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE)
 		tasklet_schedule(&raw->tlet);
 }
 
@@ -365,10 +364,11 @@ 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 */
 	}
@@ -378,13 +378,13 @@ 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;
@@ -394,11 +394,10 @@ 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);
@@ -408,7 +407,7 @@ 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:
@@ -421,7 +420,7 @@ 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) {
@@ -436,7 +435,7 @@ 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 */
@@ -448,9 +447,10 @@ 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);
 }
 
 /*
@@ -946,7 +946,7 @@ 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 */
 	/*
@@ -977,7 +977,7 @@ static void tty3215_close(struct tty_struct *tty, struct file * filp)
 	raw3215_shutdown(raw);
 	tasklet_kill(&raw->tlet);
 	tty->closing = 0;
-	raw->tty = NULL;
+	tty_port_tty_set(&raw->port, NULL);
 }
 
 /*
-- 
1.7.9.2

[PATCH] s390: fix build failure in con3215.c tty wakeup tasklet

[Paul Gortmaker]

Commit 86b26007a37d81e7aca242bb5b649473f8f81297 (tty-next)

    "TTY: con3215, use tty from tty_port"

removed the tty struct from the raw struct, causing:

  CC      drivers/s390/char/con3215.o
drivers/s390/char/con3215.c: In function 'raw3215_wakeup':
drivers/s390/char/con3215.c:339:16: error: 'struct raw3215_info' has no member named 'tty'
make[2]: *** [drivers/s390/char/con3215.o] Error 1

We can't simply add a tty to the args of raw3215_wakeup since
it is registered as a tasklet.  The flow is:

	raw3215_irq
		--> tty_port_tty_get
			--> raw3215_next_io
				--> tasklet_schedule
		--> tty_kref_put

so it seems we'll need to do a get/put in the raw3215_wakeup
tasklet as well.

Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/s390/char/con3215.c b/drivers/s390/char/con3215.c
index e928e04..759c43c 100644
--- a/drivers/s390/char/con3215.c
+++ b/drivers/s390/char/con3215.c
@@ -336,7 +336,13 @@ static inline void raw3215_try_io(struct raw3215_info *raw)
 static void raw3215_wakeup(unsigned long data)
 {
 	struct raw3215_info *raw = (struct raw3215_info *) data;
-	tty_wakeup(raw->tty);
+	struct tty_struct *tty = tty_port_tty_get(&raw->port);
+
+	if (tty == NULL)
+		return;
+
+	tty_wakeup(tty);
+	tty_kref_put(tty);
 }
 
 /*
-- 
1.7.9.1

Re: [PATCH] s390: fix build failure in con3215.c tty wakeup tasklet

[Heiko Carstens]

On Tue, Apr 17, 2012 at 12:07:09PM -0400, Paul Gortmaker wrote:
> Commit 86b26007a37d81e7aca242bb5b649473f8f81297 (tty-next)
> 
>     "TTY: con3215, use tty from tty_port"
> 
> removed the tty struct from the raw struct, causing:
> 
>   CC      drivers/s390/char/con3215.o
> drivers/s390/char/con3215.c: In function 'raw3215_wakeup':
> drivers/s390/char/con3215.c:339:16: error: 'struct raw3215_info' has no member named 'tty'
> make[2]: *** [drivers/s390/char/con3215.o] Error 1

...

> diff --git a/drivers/s390/char/con3215.c b/drivers/s390/char/con3215.c
> index e928e04..759c43c 100644
> --- a/drivers/s390/char/con3215.c
> +++ b/drivers/s390/char/con3215.c
> @@ -336,7 +336,13 @@ static inline void raw3215_try_io(struct raw3215_info *raw)
>  static void raw3215_wakeup(unsigned long data)
>  {
>  	struct raw3215_info *raw = (struct raw3215_info *) data;
> -	tty_wakeup(raw->tty);
> +	struct tty_struct *tty = tty_port_tty_get(&raw->port);
> +
> +	if (tty == NULL)
> +		return;
> +
> +	tty_wakeup(tty);
> +	tty_kref_put(tty);

Yep, I posted a similar patch earlier:
http://marc.info/?l=linux-next&m=133466152209052&w=2

The NULL check is not necessary, because "it cannot happen" ;)

Thanks,
Heiko