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authorHendrik Brueckner <brueckner@linux.vnet.ibm.com>2008-10-14 01:02:09 -0400
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2008-10-21 20:00:25 -0400
commitfebde3711992a64ea83a47a719f68a90c4b0927a (patch)
tree27f975fe9b3bd3b99a1a7043c34cf32176b7067d
parent3feebbb5492e9e463467cefb633e23a3dfcec132 (diff)
hvc_console: Add support for tty window resizing
The patch provides the hvc_resize() function to update the terminal window dimensions (struct winsize) for a specified hvc console. The function stores the new window size and schedules a function that finally updates the tty winsize and signals the change to user space (SIGWINCH). Because the winsize update must acquire a mutex and might sleep, the function is scheduled instead of being called from hvc_poll() or khvcd. This patch uses the tty_do_resize() routine from the tty layer. A pending resize work is canceled in hvc_close() and hvc_hangup(). Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
-rw-r--r--drivers/char/hvc_console.c58
-rw-r--r--drivers/char/hvc_console.h6
2 files changed, 64 insertions, 0 deletions
diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c
index 3650c904401e..2d256dc80529 100644
--- a/drivers/char/hvc_console.c
+++ b/drivers/char/hvc_console.c
@@ -374,6 +374,9 @@ static void hvc_close(struct tty_struct *tty, struct file * filp)
374 if (hp->ops->notifier_del) 374 if (hp->ops->notifier_del)
375 hp->ops->notifier_del(hp, hp->data); 375 hp->ops->notifier_del(hp, hp->data);
376 376
377 /* cancel pending tty resize work */
378 cancel_work_sync(&hp->tty_resize);
379
377 /* 380 /*
378 * Chain calls chars_in_buffer() and returns immediately if 381 * Chain calls chars_in_buffer() and returns immediately if
379 * there is no buffered data otherwise sleeps on a wait queue 382 * there is no buffered data otherwise sleeps on a wait queue
@@ -399,6 +402,9 @@ static void hvc_hangup(struct tty_struct *tty)
399 if (!hp) 402 if (!hp)
400 return; 403 return;
401 404
405 /* cancel pending tty resize work */
406 cancel_work_sync(&hp->tty_resize);
407
402 spin_lock_irqsave(&hp->lock, flags); 408 spin_lock_irqsave(&hp->lock, flags);
403 409
404 /* 410 /*
@@ -494,6 +500,39 @@ static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count
494 return written; 500 return written;
495} 501}
496 502
503/**
504 * hvc_set_winsz() - Resize the hvc tty terminal window.
505 * @work: work structure.
506 *
507 * The routine shall not be called within an atomic context because it
508 * might sleep.
509 *
510 * Locking: hp->lock
511 */
512static void hvc_set_winsz(struct work_struct *work)
513{
514 struct hvc_struct *hp;
515 unsigned long hvc_flags;
516 struct tty_struct *tty;
517 struct winsize ws;
518
519 hp = container_of(work, struct hvc_struct, tty_resize);
520 if (!hp)
521 return;
522
523 spin_lock_irqsave(&hp->lock, hvc_flags);
524 if (!hp->tty) {
525 spin_unlock_irqrestore(&hp->lock, hvc_flags);
526 return;
527 }
528 ws = hp->ws;
529 tty = tty_kref_get(hp->tty);
530 spin_unlock_irqrestore(&hp->lock, hvc_flags);
531
532 tty_do_resize(tty, tty, &ws);
533 tty_kref_put(tty);
534}
535
497/* 536/*
498 * This is actually a contract between the driver and the tty layer outlining 537 * This is actually a contract between the driver and the tty layer outlining
499 * how much write room the driver can guarantee will be sent OR BUFFERED. This 538 * how much write room the driver can guarantee will be sent OR BUFFERED. This
@@ -638,6 +677,24 @@ int hvc_poll(struct hvc_struct *hp)
638} 677}
639EXPORT_SYMBOL_GPL(hvc_poll); 678EXPORT_SYMBOL_GPL(hvc_poll);
640 679
680/**
681 * hvc_resize() - Update terminal window size information.
682 * @hp: HVC console pointer
683 * @ws: Terminal window size structure
684 *
685 * Stores the specified window size information in the hvc structure of @hp.
686 * The function schedule the tty resize update.
687 *
688 * Locking: Locking free; the function MUST be called holding hp->lock
689 */
690void hvc_resize(struct hvc_struct *hp, struct winsize ws)
691{
692 if ((hp->ws.ws_row != ws.ws_row) || (hp->ws.ws_col != ws.ws_col)) {
693 hp->ws = ws;
694 schedule_work(&hp->tty_resize);
695 }
696}
697
641/* 698/*
642 * This kthread is either polling or interrupt driven. This is determined by 699 * This kthread is either polling or interrupt driven. This is determined by
643 * calling hvc_poll() who determines whether a console adapter support 700 * calling hvc_poll() who determines whether a console adapter support
@@ -720,6 +777,7 @@ struct hvc_struct __devinit *hvc_alloc(uint32_t vtermno, int data,
720 777
721 kref_init(&hp->kref); 778 kref_init(&hp->kref);
722 779
780 INIT_WORK(&hp->tty_resize, hvc_set_winsz);
723 spin_lock_init(&hp->lock); 781 spin_lock_init(&hp->lock);
724 spin_lock(&hvc_structs_lock); 782 spin_lock(&hvc_structs_lock);
725 783
diff --git a/drivers/char/hvc_console.h b/drivers/char/hvc_console.h
index ec0e9bb0e5e6..e3359f3c9b2a 100644
--- a/drivers/char/hvc_console.h
+++ b/drivers/char/hvc_console.h
@@ -27,6 +27,7 @@
27#ifndef HVC_CONSOLE_H 27#ifndef HVC_CONSOLE_H
28#define HVC_CONSOLE_H 28#define HVC_CONSOLE_H
29#include <linux/kref.h> 29#include <linux/kref.h>
30#include <linux/tty.h>
30 31
31/* 32/*
32 * This is the max number of console adapters that can/will be found as 33 * This is the max number of console adapters that can/will be found as
@@ -56,6 +57,8 @@ struct hvc_struct {
56 struct hv_ops *ops; 57 struct hv_ops *ops;
57 int irq_requested; 58 int irq_requested;
58 int data; 59 int data;
60 struct winsize ws;
61 struct work_struct tty_resize;
59 struct list_head next; 62 struct list_head next;
60 struct kref kref; /* ref count & hvc_struct lifetime */ 63 struct kref kref; /* ref count & hvc_struct lifetime */
61}; 64};
@@ -84,6 +87,9 @@ extern int __devexit hvc_remove(struct hvc_struct *hp);
84int hvc_poll(struct hvc_struct *hp); 87int hvc_poll(struct hvc_struct *hp);
85void hvc_kick(void); 88void hvc_kick(void);
86 89
90/* Resize hvc tty terminal window */
91extern void hvc_resize(struct hvc_struct *hp, struct winsize ws);
92
87/* default notifier for irq based notification */ 93/* default notifier for irq based notification */
88extern int notifier_add_irq(struct hvc_struct *hp, int data); 94extern int notifier_add_irq(struct hvc_struct *hp, int data);
89extern void notifier_del_irq(struct hvc_struct *hp, int data); 95extern void notifier_del_irq(struct hvc_struct *hp, int data);