s390/3270: asynchronous size sensing

Convert the synchronous size sense code to an interrupt driven
approach. This allows to set the device online even if the
terminal is not connected. With the new code views can be
registered without a connected terminal, the tty can be opened
as soon as the device is online. After the terminal has been
connected and the size has been determined the tty is resized
to match the device characteristics..

Signed-off-by: Martin Schwidefsky <[e-mail]>

drivers/s390/char/raw3270.c

···
 	int minor;
 
 	short model, rows, cols;
+	unsigned int state;
 	unsigned long flags;
 
 	struct list_head req_queue;	/* Request queue. */
···
 
 	unsigned char *ascebc;		/* ascii -> ebcdic table */
 
-	struct raw3270_request init_request;
+	struct raw3270_view init_view;
+	struct raw3270_request init_reset;
+	struct raw3270_request init_readpart;
+	struct raw3270_request init_readmod;
 	unsigned char init_data[256];
 };
+
+/* raw3270->state */
+#define RAW3270_STATE_INIT	0	/* Initial state */
+#define RAW3270_STATE_RESET	1	/* Reset command is pending */
+#define RAW3270_STATE_W4ATTN	2	/* Wait for attention interrupt */
+#define RAW3270_STATE_READMOD	3	/* Read partition is pending */
+#define RAW3270_STATE_READY	4	/* Device is usable by views */
 
 /* raw3270->flags */
 #define RAW3270_FLAGS_14BITADDR	0	/* 14-bit buffer addresses */
 #define RAW3270_FLAGS_BUSY	1	/* Device busy, leave it alone */
-#define RAW3270_FLAGS_ATTN	2	/* Device sent an ATTN interrupt */
-#define RAW3270_FLAGS_READY	4	/* Device is useable by views */
-#define RAW3270_FLAGS_CONSOLE	8	/* Device is the console. */
-#define RAW3270_FLAGS_FROZEN	16	/* set if 3270 is frozen for suspend */
+#define RAW3270_FLAGS_CONSOLE	2	/* Device is the console. */
+#define RAW3270_FLAGS_FROZEN	3	/* set if 3270 is frozen for suspend */
 
 /* Semaphore to protect global data of raw3270 (devices, views, etc). */
 static DEFINE_MUTEX(raw3270_mutex);
···
 	0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
 	0xf8, 0xf9, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f
 };
+
+static inline int raw3270_state_ready(struct raw3270 *rp)
+{
+	return rp->state == RAW3270_STATE_READY;
+}
+
+static inline int raw3270_state_final(struct raw3270 *rp)
+{
+	return rp->state == RAW3270_STATE_INIT ||
+		rp->state == RAW3270_STATE_READY;
+}
 
 void
 raw3270_buffer_address(struct raw3270 *rp, char *cp, unsigned short addr)
···
  * Stop running ccw.
  */
 static int
-raw3270_halt_io_nolock(struct raw3270 *rp, struct raw3270_request *rq)
+__raw3270_halt_io(struct raw3270 *rp, struct raw3270_request *rq)
 {
 	int retries;
 	int rc;
···
 		if (rc == 0)
 			break;		/* termination successful */
 	}
-	return rc;
-}
-
-static int
-raw3270_halt_io(struct raw3270 *rp, struct raw3270_request *rq)
-{
-	unsigned long flags;
-	int rc;
-
-	spin_lock_irqsave(get_ccwdev_lock(rp->cdev), flags);
-	rc = raw3270_halt_io_nolock(rp, rq);
-	spin_unlock_irqrestore(get_ccwdev_lock(rp->cdev), flags);
 	return rc;
 }
 
···
 	if (!rp || rp->view != view ||
 	    test_bit(RAW3270_FLAGS_FROZEN, &rp->flags))
 		rc = -EACCES;
-	else if (!test_bit(RAW3270_FLAGS_READY, &rp->flags))
-		rc = -ENODEV;
+	else if (!raw3270_state_ready(rp))
+		rc = -EBUSY;
 	else
 		rc =  __raw3270_start(rp, view, rq);
 	spin_unlock_irqrestore(get_ccwdev_lock(view->dev->cdev), flags);
···
 	if (!rp || rp->view != view ||
 	    test_bit(RAW3270_FLAGS_FROZEN, &rp->flags))
 		rc = -EACCES;
-	else if (!test_bit(RAW3270_FLAGS_READY, &rp->flags))
-		rc = -ENODEV;
+	else if (!raw3270_state_ready(rp))
+		rc = -EBUSY;
 	else
 		rc =  __raw3270_start(rp, view, rq);
 	return rc;
···
 	case RAW3270_IO_STOP:
 		if (!rq)
 			break;
-		raw3270_halt_io_nolock(rp, rq);
+		__raw3270_halt_io(rp, rq);
 		rq->rc = -EIO;
 		break;
 	default:
···
 }
 
 /*
- * Size sensing.
+ * To determine the size of the 3270 device we need to do:
+ * 1) send a 'read partition' data stream to the device
+ * 2) wait for the attn interrupt that precedes the query reply
+ * 3) do a read modified to get the query reply
+ * To make things worse we have to cope with intervention
+ * required (3270 device switched to 'stand-by') and command
+ * rejects (old devices that can't do 'read partition').
  */
-
 struct raw3270_ua {	/* Query Reply structure for Usable Area */
 	struct {	/* Usable Area Query Reply Base */
 		short l;	/* Length of this structured field */
···
 	} __attribute__ ((packed)) aua;
 } __attribute__ ((packed));
 
-static struct diag210 raw3270_init_diag210;
-static DEFINE_MUTEX(raw3270_init_mutex);
-
-static int
-raw3270_init_irq(struct raw3270_view *view, struct raw3270_request *rq,
-		 struct irb *irb)
-{
-	/*
-	 * Unit-Check Processing:
-	 * Expect Command Reject or Intervention Required.
-	 */
-	if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) {
-		/* Request finished abnormally. */
-		if (irb->ecw[0] & SNS0_INTERVENTION_REQ) {
-			set_bit(RAW3270_FLAGS_BUSY, &view->dev->flags);
-			return RAW3270_IO_BUSY;
-		}
-	}
-	if (rq) {
-		if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) {
-			if (irb->ecw[0] & SNS0_CMD_REJECT)
-				rq->rc = -EOPNOTSUPP;
-			else
-				rq->rc = -EIO;
-		} else
-			/* Request finished normally. Copy residual count. */
-			rq->rescnt = irb->scsw.cmd.count;
-	}
-	if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
-		set_bit(RAW3270_FLAGS_ATTN, &view->dev->flags);
-		wake_up(&raw3270_wait_queue);
-	}
-	return RAW3270_IO_DONE;
-}
-
-static struct raw3270_fn raw3270_init_fn = {
-	.intv = raw3270_init_irq
-};
-
-static struct raw3270_view raw3270_init_view = {
-	.fn = &raw3270_init_fn
-};
-
-/*
- * raw3270_wait/raw3270_wait_interruptible/__raw3270_wakeup
- * Wait for end of request. The request must have been started
- * with raw3270_start, rc = 0. The device lock may NOT have been
- * released between calling raw3270_start and raw3270_wait.
- */
 static void
-raw3270_wake_init(struct raw3270_request *rq, void *data)
-{
-	wake_up((wait_queue_head_t *) data);
-}
-
-/*
- * Special wait function that can cope with console initialization.
- */
-static int
-raw3270_start_init(struct raw3270 *rp, struct raw3270_view *view,
-		   struct raw3270_request *rq)
-{
-	unsigned long flags;
-	int rc;
-
-#ifdef CONFIG_TN3270_CONSOLE
-	if (raw3270_registered == 0) {
-		spin_lock_irqsave(get_ccwdev_lock(view->dev->cdev), flags);
-		rq->callback = NULL;
-		rc = __raw3270_start(rp, view, rq);
-		if (rc == 0)
-			while (!raw3270_request_final(rq)) {
-				wait_cons_dev();
-				barrier();
-			}
-		spin_unlock_irqrestore(get_ccwdev_lock(view->dev->cdev), flags);
-		return rq->rc;
-	}
-#endif
-	rq->callback = raw3270_wake_init;
-	rq->callback_data = &raw3270_wait_queue;
-	spin_lock_irqsave(get_ccwdev_lock(view->dev->cdev), flags);
-	rc = __raw3270_start(rp, view, rq);
-	spin_unlock_irqrestore(get_ccwdev_lock(view->dev->cdev), flags);
-	if (rc)
-		return rc;
-	/* Now wait for the completion. */
-	rc = wait_event_interruptible(raw3270_wait_queue,
-				      raw3270_request_final(rq));
-	if (rc == -ERESTARTSYS) {	/* Interrupted by a signal. */
-		raw3270_halt_io(view->dev, rq);
-		/* No wait for the halt to complete. */
-		wait_event(raw3270_wait_queue, raw3270_request_final(rq));
-		return -ERESTARTSYS;
-	}
-	return rq->rc;
-}
-
-static int
-__raw3270_size_device_vm(struct raw3270 *rp)
+raw3270_size_device_vm(struct raw3270 *rp)
 {
 	int rc, model;
 	struct ccw_dev_id dev_id;
+	struct diag210 diag_data;
 
 	ccw_device_get_id(rp->cdev, &dev_id);
-	raw3270_init_diag210.vrdcdvno = dev_id.devno;
-	raw3270_init_diag210.vrdclen = sizeof(struct diag210);
-	rc = diag210(&raw3270_init_diag210);
-	if (rc)
-		return rc;
-	model = raw3270_init_diag210.vrdccrmd;
+	diag_data.vrdcdvno = dev_id.devno;
+	diag_data.vrdclen = sizeof(struct diag210);
+	rc = diag210(&diag_data);
+	model = diag_data.vrdccrmd;
+	/* Use default model 2 if the size could not be detected */
+	if (rc || model < 2 || model > 5)
+		model = 2;
 	switch (model) {
 	case 2:
 		rp->model = model;
···
 		rp->rows = 27;
 		rp->cols = 132;
 		break;
-	default:
-		rc = -EOPNOTSUPP;
-		break;
 	}
-	return rc;
 }
 
-static int
-__raw3270_size_device(struct raw3270 *rp)
+static void
+raw3270_size_device(struct raw3270 *rp)
 {
-	static const unsigned char wbuf[] =
-		{ 0x00, 0x07, 0x01, 0xff, 0x03, 0x00, 0x81 };
 	struct raw3270_ua *uap;
-	int rc;
 
-	/*
-	 * To determine the size of the 3270 device we need to do:
-	 * 1) send a 'read partition' data stream to the device
-	 * 2) wait for the attn interrupt that precedes the query reply
-	 * 3) do a read modified to get the query reply
-	 * To make things worse we have to cope with intervention
-	 * required (3270 device switched to 'stand-by') and command
-	 * rejects (old devices that can't do 'read partition').
-	 */
-	memset(&rp->init_request, 0, sizeof(rp->init_request));
-	memset(&rp->init_data, 0, 256);
-	/* Store 'read partition' data stream to init_data */
-	memcpy(&rp->init_data, wbuf, sizeof(wbuf));
-	INIT_LIST_HEAD(&rp->init_request.list);
-	rp->init_request.ccw.cmd_code = TC_WRITESF;
-	rp->init_request.ccw.flags = CCW_FLAG_SLI;
-	rp->init_request.ccw.count = sizeof(wbuf);
-	rp->init_request.ccw.cda = (__u32) __pa(&rp->init_data);
-
-	rc = raw3270_start_init(rp, &raw3270_init_view, &rp->init_request);
-	if (rc)
-		/* Check error cases: -ERESTARTSYS, -EIO and -EOPNOTSUPP */
-		return rc;
-
-	/* Wait for attention interrupt. */
-#ifdef CONFIG_TN3270_CONSOLE
-	if (raw3270_registered == 0) {
-		unsigned long flags;
-
-		spin_lock_irqsave(get_ccwdev_lock(rp->cdev), flags);
-		while (!test_and_clear_bit(RAW3270_FLAGS_ATTN, &rp->flags))
-			wait_cons_dev();
-		spin_unlock_irqrestore(get_ccwdev_lock(rp->cdev), flags);
-	} else
-#endif
-		rc = wait_event_interruptible(raw3270_wait_queue,
-			test_and_clear_bit(RAW3270_FLAGS_ATTN, &rp->flags));
-	if (rc)
-		return rc;
-
-	/*
-	 * The device accepted the 'read partition' command. Now
-	 * set up a read ccw and issue it.
-	 */
-	rp->init_request.ccw.cmd_code = TC_READMOD;
-	rp->init_request.ccw.flags = CCW_FLAG_SLI;
-	rp->init_request.ccw.count = sizeof(rp->init_data);
-	rp->init_request.ccw.cda = (__u32) __pa(rp->init_data);
-	rc = raw3270_start_init(rp, &raw3270_init_view, &rp->init_request);
-	if (rc)
-		return rc;
 	/* Got a Query Reply */
 	uap = (struct raw3270_ua *) (rp->init_data + 1);
 	/* Paranoia check. */
-	if (rp->init_data[0] != 0x88 || uap->uab.qcode != 0x81)
-		return -EOPNOTSUPP;
+	if (rp->init_readmod.rc || rp->init_data[0] != 0x88 ||
+	    uap->uab.qcode != 0x81) {
+		/* Couldn't detect size. Use default model 2. */
+		rp->model = 2;
+		rp->rows = 24;
+		rp->cols = 80;
+		return;
+	}
 	/* Copy rows/columns of default Usable Area */
 	rp->rows = uap->uab.h;
 	rp->cols = uap->uab.w;
···
 		rp->rows = uap->aua.hauai;
 		rp->cols = uap->aua.wauai;
 	}
-	return 0;
+	/* Try to find a model. */
+	rp->model = 0;
+	if (rp->rows == 24 && rp->cols == 80)
+		rp->model = 2;
+	if (rp->rows == 32 && rp->cols == 80)
+		rp->model = 3;
+	if (rp->rows == 43 && rp->cols == 80)
+		rp->model = 4;
+	if (rp->rows == 27 && rp->cols == 132)
+		rp->model = 5;
+}
+
+static void
+raw3270_size_device_done(struct raw3270 *rp)
+{
+	struct raw3270_view *view;
+
+	rp->view = NULL;
+	rp->state = RAW3270_STATE_READY;
+	/* Notify views about new size */
+	list_for_each_entry(view, &rp->view_list, list)
+		if (view->fn->resize)
+			view->fn->resize(view, rp->model, rp->rows, rp->cols);
+	/* Setup processing done, now activate a view */
+	list_for_each_entry(view, &rp->view_list, list) {
+		rp->view = view;
+		if (view->fn->activate(view) == 0)
+			break;
+		rp->view = NULL;
+	}
+}
+
+static void
+raw3270_read_modified_cb(struct raw3270_request *rq, void *data)
+{
+	struct raw3270 *rp = rq->view->dev;
+
+	raw3270_size_device(rp);
+	raw3270_size_device_done(rp);
+}
+
+static void
+raw3270_read_modified(struct raw3270 *rp)
+{
+	if (rp->state != RAW3270_STATE_W4ATTN)
+		return;
+	/* Use 'read modified' to get the result of a read partition. */
+	memset(&rp->init_readmod, 0, sizeof(rp->init_readmod));
+	memset(&rp->init_data, 0, sizeof(rp->init_data));
+	rp->init_readmod.ccw.cmd_code = TC_READMOD;
+	rp->init_readmod.ccw.flags = CCW_FLAG_SLI;
+	rp->init_readmod.ccw.count = sizeof(rp->init_data);
+	rp->init_readmod.ccw.cda = (__u32) __pa(rp->init_data);
+	rp->init_readmod.callback = raw3270_read_modified_cb;
+	rp->state = RAW3270_STATE_READMOD;
+	raw3270_start_irq(&rp->init_view, &rp->init_readmod);
+}
+
+static void
+raw3270_writesf_readpart(struct raw3270 *rp)
+{
+	static const unsigned char wbuf[] =
+		{ 0x00, 0x07, 0x01, 0xff, 0x03, 0x00, 0x81 };
+
+	/* Store 'read partition' data stream to init_data */
+	memset(&rp->init_readpart, 0, sizeof(rp->init_readpart));
+	memset(&rp->init_data, 0, sizeof(rp->init_data));
+	memcpy(&rp->init_data, wbuf, sizeof(wbuf));
+	rp->init_readpart.ccw.cmd_code = TC_WRITESF;
+	rp->init_readpart.ccw.flags = CCW_FLAG_SLI;
+	rp->init_readpart.ccw.count = sizeof(wbuf);
+	rp->init_readpart.ccw.cda = (__u32) __pa(&rp->init_data);
+	rp->state = RAW3270_STATE_W4ATTN;
+	raw3270_start_irq(&rp->init_view, &rp->init_readpart);
+}
+
+/*
+ * Device reset
+ */
+static void
+raw3270_reset_device_cb(struct raw3270_request *rq, void *data)
+{
+	struct raw3270 *rp = rq->view->dev;
+
+	if (rp->state != RAW3270_STATE_RESET)
+		return;
+	if (rq && rq->rc) {
+		/* Reset command failed. */
+		rp->state = RAW3270_STATE_INIT;
+	} else if (0 && MACHINE_IS_VM) {
+		raw3270_size_device_vm(rp);
+		raw3270_size_device_done(rp);
+	} else
+		raw3270_writesf_readpart(rp);
 }
 
 static int
-raw3270_size_device(struct raw3270 *rp)
+__raw3270_reset_device(struct raw3270 *rp)
 {
 	int rc;
 
-	mutex_lock(&raw3270_init_mutex);
-	rp->view = &raw3270_init_view;
-	raw3270_init_view.dev = rp;
-	if (MACHINE_IS_VM)
-		rc = __raw3270_size_device_vm(rp);
-	else
-		rc = __raw3270_size_device(rp);
-	raw3270_init_view.dev = NULL;
-	rp->view = NULL;
-	mutex_unlock(&raw3270_init_mutex);
-	if (rc == 0) {	/* Found something. */
-		/* Try to find a model. */
-		rp->model = 0;
-		if (rp->rows == 24 && rp->cols == 80)
-			rp->model = 2;
-		if (rp->rows == 32 && rp->cols == 80)
-			rp->model = 3;
-		if (rp->rows == 43 && rp->cols == 80)
-			rp->model = 4;
-		if (rp->rows == 27 && rp->cols == 132)
-			rp->model = 5;
-	} else {
-		/* Couldn't detect size. Use default model 2. */
-		rp->model = 2;
-		rp->rows = 24;
-		rp->cols = 80;
-		return 0;
-	}
+	/* Store reset data stream to init_data/init_reset */
+	memset(&rp->init_reset, 0, sizeof(rp->init_reset));
+	memset(&rp->init_data, 0, sizeof(rp->init_data));
+	rp->init_data[0] = TW_KR;
+	rp->init_reset.ccw.cmd_code = TC_EWRITEA;
+	rp->init_reset.ccw.flags = CCW_FLAG_SLI;
+	rp->init_reset.ccw.count = 1;
+	rp->init_reset.ccw.cda = (__u32) __pa(rp->init_data);
+	rp->init_reset.callback = raw3270_reset_device_cb;
+	rc = __raw3270_start(rp, &rp->init_view, &rp->init_reset);
+	if (rc == 0 && rp->state == RAW3270_STATE_INIT)
+		rp->state = RAW3270_STATE_RESET;
 	return rc;
 }
 
 static int
 raw3270_reset_device(struct raw3270 *rp)
 {
+	unsigned long flags;
 	int rc;
 
-	mutex_lock(&raw3270_init_mutex);
-	memset(&rp->init_request, 0, sizeof(rp->init_request));
-	memset(&rp->init_data, 0, sizeof(rp->init_data));
-	/* Store reset data stream to init_data/init_request */
-	rp->init_data[0] = TW_KR;
-	INIT_LIST_HEAD(&rp->init_request.list);
-	rp->init_request.ccw.cmd_code = TC_EWRITEA;
-	rp->init_request.ccw.flags = CCW_FLAG_SLI;
-	rp->init_request.ccw.count = 1;
-	rp->init_request.ccw.cda = (__u32) __pa(rp->init_data);
-	rp->view = &raw3270_init_view;
-	raw3270_init_view.dev = rp;
-	rc = raw3270_start_init(rp, &raw3270_init_view, &rp->init_request);
-	raw3270_init_view.dev = NULL;
-	rp->view = NULL;
-	mutex_unlock(&raw3270_init_mutex);
+	spin_lock_irqsave(get_ccwdev_lock(rp->cdev), flags);
+	rc = __raw3270_reset_device(rp);
+	spin_unlock_irqrestore(get_ccwdev_lock(rp->cdev), flags);
 	return rc;
 }
 
···
 	if (!rp || rp->view != view ||
 	    test_bit(RAW3270_FLAGS_FROZEN, &rp->flags))
 		rc = -EACCES;
-	else if (!test_bit(RAW3270_FLAGS_READY, &rp->flags))
-		rc = -ENODEV;
+	else if (!raw3270_state_ready(rp))
+		rc = -EBUSY;
 	else
 		rc = raw3270_reset_device(view->dev);
 	return rc;
 }
+
+static int
+raw3270_init_irq(struct raw3270_view *view, struct raw3270_request *rq,
+		 struct irb *irb)
+{
+	struct raw3270 *rp;
+
+	/*
+	 * Unit-Check Processing:
+	 * Expect Command Reject or Intervention Required.
+	 */
+	if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) {
+		/* Request finished abnormally. */
+		if (irb->ecw[0] & SNS0_INTERVENTION_REQ) {
+			set_bit(RAW3270_FLAGS_BUSY, &view->dev->flags);
+			return RAW3270_IO_BUSY;
+		}
+	}
+	if (rq) {
+		if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) {
+			if (irb->ecw[0] & SNS0_CMD_REJECT)
+				rq->rc = -EOPNOTSUPP;
+			else
+				rq->rc = -EIO;
+		}
+	}
+	if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
+		/* Queue read modified after attention interrupt */
+		rp = view->dev;
+		raw3270_read_modified(rp);
+	}
+	return RAW3270_IO_DONE;
+}
+
+static struct raw3270_fn raw3270_init_fn = {
+	.intv = raw3270_init_irq
+};
 
 /*
  * Setup new 3270 device.
···
 
 	INIT_LIST_HEAD(&rp->req_queue);
 	INIT_LIST_HEAD(&rp->view_list);
+
+	rp->init_view.dev = rp;
+	rp->init_view.fn = &raw3270_init_fn;
+	rp->view = &rp->init_view;
 
 	/*
 	 * Add device to list and find the smallest unused minor
···
  */
 struct raw3270 __init *raw3270_setup_console(struct ccw_device *cdev)
 {
+	unsigned long flags;
 	struct raw3270 *rp;
 	char *ascebc;
 	int rc;
···
 	if (rc)
 		return ERR_PTR(rc);
 	set_bit(RAW3270_FLAGS_CONSOLE, &rp->flags);
-	rc = raw3270_reset_device(rp);
-	if (rc)
-		return ERR_PTR(rc);
-	rc = raw3270_size_device(rp);
-	if (rc)
-		return ERR_PTR(rc);
-	rc = raw3270_reset_device(rp);
-	if (rc)
-		return ERR_PTR(rc);
-	set_bit(RAW3270_FLAGS_READY, &rp->flags);
+	spin_lock_irqsave(get_ccwdev_lock(rp->cdev), flags);
+	do {
+		__raw3270_reset_device(rp);
+		while (!raw3270_state_final(rp)) {
+			wait_cons_dev();
+			barrier();
+		}
+	} while (rp->state != RAW3270_STATE_READY);
+	spin_unlock_irqrestore(get_ccwdev_lock(rp->cdev), flags);
 	return rp;
 }
 
···
 	spin_lock_irqsave(get_ccwdev_lock(rp->cdev), flags);
 	if (rp->view == view)
 		rc = 0;
-	else if (!test_bit(RAW3270_FLAGS_READY, &rp->flags))
-		rc = -ENODEV;
+	else if (!raw3270_state_ready(rp))
+		rc = -EBUSY;
 	else if (test_bit(RAW3270_FLAGS_FROZEN, &rp->flags))
 		rc = -EACCES;
 	else {
 		oldview = NULL;
-		if (rp->view) {
+		if (rp->view && rp->view->fn->deactivate) {
 			oldview = rp->view;
 			oldview->fn->deactivate(oldview);
 		}
···
 		list_del_init(&view->list);
 		list_add_tail(&view->list, &rp->view_list);
 		/* Try to activate another view. */
-		if (test_bit(RAW3270_FLAGS_READY, &rp->flags) &&
+		if (raw3270_state_ready(rp) &&
 		    !test_bit(RAW3270_FLAGS_FROZEN, &rp->flags)) {
 			list_for_each_entry(view, &rp->view_list, list) {
 				rp->view = view;
···
 		if (rp->minor != minor)
 			continue;
 		spin_lock_irqsave(get_ccwdev_lock(rp->cdev), flags);
-		if (test_bit(RAW3270_FLAGS_READY, &rp->flags)) {
-			atomic_set(&view->ref_count, 2);
-			view->dev = rp;
-			view->fn = fn;
-			view->model = rp->model;
-			view->rows = rp->rows;
-			view->cols = rp->cols;
-			view->ascebc = rp->ascebc;
-			spin_lock_init(&view->lock);
-			list_add(&view->list, &rp->view_list);
-			rc = 0;
-		}
+		atomic_set(&view->ref_count, 2);
+		view->dev = rp;
+		view->fn = fn;
+		view->model = rp->model;
+		view->rows = rp->rows;
+		view->cols = rp->cols;
+		view->ascebc = rp->ascebc;
+		spin_lock_init(&view->lock);
+		list_add(&view->list, &rp->view_list);
+		rc = 0;
 		spin_unlock_irqrestore(get_ccwdev_lock(rp->cdev), flags);
 		break;
 	}
···
 		if (rp->minor != minor)
 			continue;
 		spin_lock_irqsave(get_ccwdev_lock(rp->cdev), flags);
-		if (test_bit(RAW3270_FLAGS_READY, &rp->flags)) {
-			view = ERR_PTR(-ENOENT);
-			list_for_each_entry(tmp, &rp->view_list, list) {
-				if (tmp->fn == fn) {
-					raw3270_get_view(tmp);
-					view = tmp;
-					break;
-				}
+		list_for_each_entry(tmp, &rp->view_list, list) {
+			if (tmp->fn == fn) {
+				raw3270_get_view(tmp);
+				view = tmp;
+				break;
 			}
 		}
 		spin_unlock_irqrestore(get_ccwdev_lock(rp->cdev), flags);
···
 		rp->view = NULL;
 	}
 	list_del_init(&view->list);
-	if (!rp->view && test_bit(RAW3270_FLAGS_READY, &rp->flags) &&
+	if (!rp->view && raw3270_state_ready(rp) &&
 	    !test_bit(RAW3270_FLAGS_FROZEN, &rp->flags)) {
 		/* Try to activate another view. */
 		list_for_each_entry(nv, &rp->view_list, list) {
···
 	rp = raw3270_create_device(cdev);
 	if (IS_ERR(rp))
 		return PTR_ERR(rp);
-	rc = raw3270_reset_device(rp);
-	if (rc)
-		goto failure;
-	rc = raw3270_size_device(rp);
-	if (rc)
-		goto failure;
-	rc = raw3270_reset_device(rp);
-	if (rc)
-		goto failure;
 	rc = raw3270_create_attributes(rp);
 	if (rc)
 		goto failure;
-	set_bit(RAW3270_FLAGS_READY, &rp->flags);
+	raw3270_reset_device(rp);
 	mutex_lock(&raw3270_mutex);
 	list_for_each_entry(np, &raw3270_notifier, list)
 		np->create(rp->minor);
···
 	 */
 	if (rp == NULL)
 		return;
-	clear_bit(RAW3270_FLAGS_READY, &rp->flags);
 
 	sysfs_remove_group(&cdev->dev.kobj, &raw3270_attr_group);
 
 	/* Deactivate current view and remove all views. */
 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
 	if (rp->view) {
-		rp->view->fn->deactivate(rp->view);
+		if (rp->view->fn->deactivate)
+			rp->view->fn->deactivate(rp->view);
 		rp->view = NULL;
 	}
 	while (!list_empty(&rp->view_list)) {
···
 	if (!rp)
 		return 0;
 	spin_lock_irqsave(get_ccwdev_lock(rp->cdev), flags);
-	if (rp->view)
+	if (rp->view && rp->view->fn->deactivate)
 		rp->view->fn->deactivate(rp->view);
 	if (!test_bit(RAW3270_FLAGS_CONSOLE, &rp->flags)) {
 		/*
···
 		return 0;
 	spin_lock_irqsave(get_ccwdev_lock(rp->cdev), flags);
 	clear_bit(RAW3270_FLAGS_FROZEN, &rp->flags);
-	if (rp->view)
+	if (rp->view && rp->view->fn->activate)
 		rp->view->fn->activate(rp->view);
 	spin_unlock_irqrestore(get_ccwdev_lock(rp->cdev), flags);
 	return 0;

drivers/s390/char/raw3270.h

···
 		     struct raw3270_request *, struct irb *);
 	void (*release)(struct raw3270_view *);
 	void (*free)(struct raw3270_view *);
+	void (*resize)(struct raw3270_view *, int, int, int);
 };
 
 /*

drivers/s390/char/tty3270.c

···
 #include <linux/init.h>
 #include <linux/console.h>
 #include <linux/interrupt.h>
+#include <linux/workqueue.h>
 
 #include <linux/slab.h>
 #include <linux/bootmem.h>
···
 	unsigned int highlight;		/* Blink/reverse/underscore */
 	unsigned int f_color;		/* Foreground color */
 	struct tty3270_line *screen;
+	unsigned int n_model, n_cols, n_rows;	/* New model & size */
+	struct work_struct resize_work;
 
 	/* Input stuff. */
 	struct string *prompt;		/* Output string for input area. */
···
 #define TTY_UPDATE_ALL		16	/* Recreate screen. */
 
 static void tty3270_update(struct tty3270 *);
+static void tty3270_resize_work(struct work_struct *work);
 
 /*
  * Setup timeout for a device. On timeout trigger an update.
···
 	tasklet_init(&tp->readlet,
 		     (void (*)(unsigned long)) tty3270_read_tasklet,
 		     (unsigned long) tp->read);
+	INIT_WORK(&tp->resize_work, tty3270_resize_work);
 
 	return tp;
 
···
 /*
  * Allocate tty3270 screen.
  */
-static int
-tty3270_alloc_screen(struct tty3270 *tp)
+static struct tty3270_line *
+tty3270_alloc_screen(unsigned int rows, unsigned int cols)
 {
+	struct tty3270_line *screen;
 	unsigned long size;
 	int lines;
 
-	size = sizeof(struct tty3270_line) * (tp->view.rows - 2);
-	tp->screen = kzalloc(size, GFP_KERNEL);
-	if (!tp->screen)
+	size = sizeof(struct tty3270_line) * (rows - 2);
+	screen = kzalloc(size, GFP_KERNEL);
+	if (!screen)
 		goto out_err;
-	for (lines = 0; lines < tp->view.rows - 2; lines++) {
-		size = sizeof(struct tty3270_cell) * tp->view.cols;
-		tp->screen[lines].cells = kzalloc(size, GFP_KERNEL);
-		if (!tp->screen[lines].cells)
+	for (lines = 0; lines < rows - 2; lines++) {
+		size = sizeof(struct tty3270_cell) * cols;
+		screen[lines].cells = kzalloc(size, GFP_KERNEL);
+		if (!screen[lines].cells)
 			goto out_screen;
 	}
-	return 0;
+	return screen;
 out_screen:
 	while (lines--)
-		kfree(tp->screen[lines].cells);
-	kfree(tp->screen);
+		kfree(screen[lines].cells);
+	kfree(screen);
 out_err:
-	return -ENOMEM;
+	return ERR_PTR(-ENOMEM);
 }
 
 /*
  * Free tty3270 screen.
  */
 static void
-tty3270_free_screen(struct tty3270 *tp)
+tty3270_free_screen(struct tty3270_line *screen, unsigned int rows)
 {
 	int lines;
 
-	for (lines = 0; lines < tp->view.rows - 2; lines++)
-		kfree(tp->screen[lines].cells);
-	kfree(tp->screen);
+	for (lines = 0; lines < rows - 2; lines++)
+		kfree(screen[lines].cells);
+	kfree(screen);
+}
+
+/*
+ * Resize tty3270 screen
+ */
+static void tty3270_resize_work(struct work_struct *work)
+{
+	struct tty3270 *tp = container_of(work, struct tty3270, resize_work);
+	struct tty3270_line *screen, *oscreen;
+	struct tty_struct *tty;
+	unsigned int orows;
+	struct winsize ws;
+
+	screen = tty3270_alloc_screen(tp->n_rows, tp->n_cols);
+	if (!screen)
+		return;
+	/* Switch to new output size */
+	spin_lock_bh(&tp->view.lock);
+	oscreen = tp->screen;
+	orows = tp->view.rows;
+	tp->view.model = tp->n_model;
+	tp->view.rows = tp->n_rows;
+	tp->view.cols = tp->n_cols;
+	tp->screen = screen;
+	free_string(&tp->freemem, tp->prompt);
+	free_string(&tp->freemem, tp->status);
+	tty3270_create_prompt(tp);
+	tty3270_create_status(tp);
+	tp->nr_up = 0;
+	while (tp->nr_lines < tp->view.rows - 2)
+		tty3270_blank_line(tp);
+	tp->update_flags = TTY_UPDATE_ALL;
+	spin_unlock_bh(&tp->view.lock);
+	tty3270_free_screen(oscreen, orows);
+	tty3270_set_timer(tp, 1);
+	/* Informat tty layer about new size */
+	tty = tty_port_tty_get(&tp->port);
+	if (!tty)
+		return;
+	ws.ws_row = tp->view.rows - 2;
+	ws.ws_col = tp->view.cols;
+	tty_do_resize(tty, &ws);
+}
+
+static void
+tty3270_resize(struct raw3270_view *view, int model, int rows, int cols)
+{
+	struct tty3270 *tp = container_of(view, struct tty3270, view);
+
+	tp->n_model = model;
+	tp->n_rows = rows;
+	tp->n_cols = cols;
+	schedule_work(&tp->resize_work);
 }
 
 /*
···
 tty3270_free(struct raw3270_view *view)
 {
 	struct tty3270 *tp = container_of(view, struct tty3270, view);
-	tty3270_free_screen(tp);
+
+	tty3270_free_screen(tp->screen, tp->view.rows);
 	tty3270_free_view(tp);
 }
 
···
 	.deactivate = tty3270_deactivate,
 	.intv = (void *) tty3270_irq,
 	.release = tty3270_release,
-	.free = tty3270_free
+	.free = tty3270_free,
+	.resize = tty3270_resize
 };
 
 /*
···
 	if (tty3270_max_index < tty->index)
 		tty3270_max_index = tty->index;
 
-	/* Quick exit if there is no device for tty->index. */
-	if (PTR_ERR(view) == -ENODEV)
-		return -ENODEV;
-
 	/* Allocate tty3270 structure on first open. */
 	tp = tty3270_alloc_view();
 	if (IS_ERR(tp))
···
 		return rc;
 	}
 
-	rc = tty3270_alloc_screen(tp);
-	if (rc) {
+	tp->screen = tty3270_alloc_screen(tp->view.cols, tp->view.rows);
+	if (IS_ERR(tp->screen)) {
+		rc = PTR_ERR(tp->screen);
 		raw3270_put_view(&tp->view);
 		raw3270_del_view(&tp->view);
+		tty3270_free_view(tp);
 		return rc;
 	}
 

drivers/tty/tty_io.c

···
 	mutex_unlock(&tty->termios_mutex);
 	return 0;
 }
+EXPORT_SYMBOL(tty_do_resize);
 
 /**
  *	tiocswinsz		-	implement window size set ioctl