From: Hendrik Brueckner <[EMAIL PROTECTED]>
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.
Acked-by: Christian Borntraeger <[EMAIL PROTECTED]>
Signed-off-by: Hendrik Brueckner <[EMAIL PROTECTED]>
---
drivers/char/hvc_console.c | 61 +++++++++++++++++++++++++++++++++++++++++++++
drivers/char/hvc_console.h | 6 ++++
2 files changed, 67 insertions(+)
--- a/drivers/char/hvc_console.c
+++ b/drivers/char/hvc_console.c
@@ -494,6 +494,48 @@ static int hvc_write(struct tty_struct *
return written;
}
+/**
+ * hvc_set_winsz() - Resize the hvc tty terminal window.
+ * @work: work structure.
+ *
+ * The routine shall not be called within an atomic context because it
+ * acquires the tty termios mutex and might sleep.
+ *
+ * Locking: hp->lock, tty->termios_mutex and tty->ctrl_lock
+ */
+static void hvc_set_winsz(struct work_struct *work)
+{
+ struct hvc_struct *hp;
+ struct pid *pgrp;
+ unsigned long hvc_flags;
+ unsigned long ctrl_flags;
+
+ hp = container_of(work, struct hvc_struct, tty_resize);
+ if (!hp || !hp->tty)
+ return;
+
+ mutex_lock(&hp->tty->termios_mutex);
+ spin_lock_irqsave(&hp->lock, hvc_flags);
+
+ if ((hp->ws.ws_row == hp->tty->winsize.ws_row) &&
+ (hp->ws.ws_col == hp->tty->winsize.ws_col))
+ goto out_mutex_unlock;
+
+ spin_lock_irqsave(&hp->tty->ctrl_lock, ctrl_flags);
+ pgrp = get_pid(hp->tty->pgrp);
+ spin_unlock_irqrestore(&hp->tty->ctrl_lock, ctrl_flags);
+
+ if (pgrp)
+ kill_pgrp(pgrp, SIGWINCH, 1);
+ put_pid(pgrp);
+
+ hp->tty->winsize = hp->ws;
+
+out_mutex_unlock:
+ spin_unlock_irqrestore(&hp->lock, hvc_flags);
+ mutex_unlock(&hp->tty->termios_mutex);
+}
+
/*
* This is actually a contract between the driver and the tty layer outlining
* how much write room the driver can guarantee will be sent OR BUFFERED. This
@@ -638,6 +680,24 @@ int hvc_poll(struct hvc_struct *hp)
}
EXPORT_SYMBOL_GPL(hvc_poll);
+/**
+ * hvc_resize() - Update terminal window size information.
+ * @hp: HVC console pointer
+ * @ws: Terminal window size structure
+ *
+ * Stores the specified window size information in the hvc structure of @hp.
+ * The function schedule the tty resize update.
+ *
+ * Locking: Locking free; the function MUST be called holding hp->lock
+ */
+void hvc_resize(struct hvc_struct *hp, struct winsize ws)
+{
+ if ((hp->ws.ws_row != ws.ws_row) || (hp->ws.ws_col != ws.ws_col)) {
+ hp->ws = ws;
+ schedule_work(&hp->tty_resize);
+ }
+}
+
/*
* This kthread is either polling or interrupt driven. This is determined by
* calling hvc_poll() who determines whether a console adapter support
@@ -720,6 +780,7 @@ struct hvc_struct __devinit *hvc_alloc(u
kref_init(&hp->kref);
+ INIT_WORK(&hp->tty_resize, hvc_set_winsz);
spin_lock_init(&hp->lock);
spin_lock(&hvc_structs_lock);
--- a/drivers/char/hvc_console.h
+++ b/drivers/char/hvc_console.h
@@ -27,6 +27,7 @@
#ifndef HVC_CONSOLE_H
#define HVC_CONSOLE_H
#include <linux/kref.h>
+#include <linux/tty.h>
/*
* This is the max number of console adapters that can/will be found as
@@ -56,6 +57,8 @@ struct hvc_struct {
struct hv_ops *ops;
int irq_requested;
int data;
+ struct winsize ws;
+ struct work_struct tty_resize;
struct list_head next;
struct kref kref; /* ref count & hvc_struct lifetime */
};
@@ -84,6 +87,9 @@ extern int __devexit hvc_remove(struct h
int hvc_poll(struct hvc_struct *hp);
void hvc_kick(void);
+/* Resize hvc tty terminal window */
+extern void hvc_resize(struct hvc_struct *hp, struct winsize ws);
+
/* default notifier for irq based notification */
extern int notifier_add_irq(struct hvc_struct *hp, int data);
extern void notifier_del_irq(struct hvc_struct *hp, int data);
--
Hendrik Brueckner
D/3303 Linux on System z Development
Tel: +49 7031 16-1073
Fax: +49 7031 16-3456
eMail: [EMAIL PROTECTED]
IBM Deutschland Research & Development GmbH, Schoenaicher Str. 220, 71032
Boeblingen
IBM Deutschland Research & Development GmbH
Vorsitzender des Aufsichtsrats: Martin Jetter
Geschaeftsfuehrung: Erich Baier
Sitz der Gesellschaft: Boeblingen
Registergericht: Amtsgericht Stuttgart, HRB 243294
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