From: Hendrik Brueckner 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 Signed-off-by: Hendrik Brueckner --- 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 +#include /* * 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: brueckner@linux.vnet.ibm.com 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/