Merge tag 'tty-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull TTY updates from Greg Kroah-Hartman:
 "Here's the big TTY/serial driver pull request for the 3.5-rc1 merge
  window.

  Nothing major in here, just lots of incremental changes from Alan and
  Jiri reworking some tty core things to behave better and to get a more
  solid grasp on some of the nasty tty locking issues.

  There are a few tty and serial driver updates in here as well.

  All of this has been in the linux-next releases for a while with no
  problems.

  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

* tag 'tty-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (115 commits)
  serial: bfin_uart: Make MMR access compatible with 32 bits bf609 style controller.
  serial: bfin_uart: RTS and CTS MMRs can be either 16-bit width or 32-bit width.
  serial: bfin_uart: narrow the reboot condition in DMA tx interrupt
  serial: bfin_uart: Adapt bf5xx serial driver to bf60x serial4 controller.
  Revert "serial_core: Update buffer overrun statistics."
  tty: hvc_xen: NULL dereference on allocation failure
  tty: Fix LED error return
  tty: Allow uart_register/unregister/register
  tty: move global ldisc idle waitqueue to the individual ldisc
  serial8250-em: Add DT support
  serial8250-em: clk_get() IS_ERR() error handling fix
  serial_core: Update buffer overrun statistics.
  tty: drop the pty lock during hangup
  cris: fix missing tty arg in wait_event_interruptible_tty call
  tty/amiserial: Add missing argument for tty_unlock()
  tty_lock: Localise the lock
  pty: Lock the devpts bits privately
  tty_lock: undo the old tty_lock use on the ctty
  serial8250-em: Emma Mobile UART driver V2
  Add missing call to uart_update_timeout()
  ...

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 */
@@ -84,7 +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 */
@@ -293,7 +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);
 		}
@@ -309,7 +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);
@@ -324,10 +323,7 @@ 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;
 		}
@@ -340,17 +336,21 @@ 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 = tty_port_tty_get(&raw->port);
+	tty_wakeup(tty);
+	tty_kref_put(tty);
 }
 
 /*
  * 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);
 }
 
@@ -368,10 +368,11 @@ 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 */
 	}
@@ -381,13 +382,13 @@ 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;
@@ -397,11 +398,10 @@ 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);
@@ -411,7 +411,7 @@ 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:
@@ -424,7 +424,7 @@ 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) {
@@ -439,7 +439,7 @@ 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 */
@@ -451,9 +451,10 @@ 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);
 }
 
 /*
@@ -487,7 +488,7 @@ 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;
 		}
@@ -609,10 +610,10 @@ 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);
@@ -628,14 +629,15 @@ 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);
@@ -643,11 +645,41 @@ 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);
 }
 
+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);
+	tty_port_init(&info->port);
+
+	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 +688,15 @@ 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 +706,10 @@ 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 +721,7 @@ 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);
 	}
 }
 
@@ -741,7 +758,7 @@ 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 +771,7 @@ 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 +844,7 @@ 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 .. */
@@ -897,23 +914,16 @@ 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;
 	}
@@ -940,7 +950,7 @@ 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 */
 	/*
@@ -971,7 +981,7 @@ 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);
 }
 
 /*

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);

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);
 }

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) {

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 {
@@ -56,8 +55,7 @@ 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 +114,7 @@ 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 +140,10 @@ 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 +461,12 @@ 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 +480,11 @@ 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);
 }
 
 /*
@@ -491,10 +494,7 @@ static int
 sclp_vt220_open(struct tty_struct *tty, struct file *filp)
 {
 	if (tty->count == 1) {
-		sclp_vt220_tty = tty;
-		tty->driver_data = kmalloc(SCLP_VT220_BUF_SIZE, GFP_KERNEL);
-		if (tty->driver_data == NULL)
-			return -ENOMEM;
+		tty_port_tty_set(&sclp_vt220_port, tty);
 		tty->low_latency = 0;
 		if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
 			tty->winsize.ws_row = 24;
@@ -510,11 +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) {
-		sclp_vt220_tty = NULL;
-		kfree(tty->driver_data);
-		tty->driver_data = NULL;
-	}
+	if (tty->count == 1)
+		tty_port_tty_set(&sclp_vt220_port, NULL);
 }
 
 /*
@@ -635,9 +632,9 @@ 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 */

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. */
 
@@ -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;
@@ -450,10 +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)
@@ -478,9 +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);
 }
 
@@ -490,10 +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)
@@ -513,10 +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)
@@ -537,11 +532,10 @@ 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
@@ -577,13 +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);
@@ -596,9 +587,10 @@ 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 +627,8 @@ 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 +637,8 @@ 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);
 }
 
@@ -690,6 +680,17 @@ 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;
+	tty_port_init(&tp->port);
+	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);
@@ -794,16 +795,15 @@ tty3270_free_screen(struct tty3270 *tp)
 static void
 tty3270_release(struct raw3270_view *view)
 {
-	struct tty3270 *tp;
-	struct tty_struct *tty;
+	struct tty3270 *tp = container_of(view, struct tty3270, view);
+	struct tty_struct *tty = tty_port_tty_get(&tp->port);
 
-	tp = (struct tty3270 *) view;
-	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);
 	}
 }
 
@@ -813,8 +813,9 @@ 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);
 }
 
 /*
@@ -823,14 +824,13 @@ 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);
 	}
 }
 
@@ -848,22 +848,23 @@ 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;
 		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;
 	}
@@ -871,7 +872,7 @@ 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. */
@@ -879,16 +880,6 @@ 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) {
@@ -903,7 +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;
@@ -917,7 +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;
@@ -935,14 +926,13 @@ 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;
+		tty_port_tty_set(&tp->port, NULL);
 		raw3270_put_view(&tp->view);
 	}
 }
@@ -1391,7 +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;
@@ -1437,11 +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;
 	}
@@ -1513,12 +1503,13 @@ 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]);
@@ -1595,10 +1586,10 @@ 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;
 }
 
@@ -1629,7 +1620,7 @@ 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;
 	}
 }