diff options
author | Jiri Slaby <jslaby@suse.cz> | 2012-03-05 14:51:59 +0100 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-03-08 20:42:21 +0100 |
commit | 54089d4cdc89732e65f968209d10aae542482c0c (patch) | |
tree | 4794ce3d78e77af45f91995182536b4bd7cfd320 /arch/alpha | |
parent | ALPHA: srmcons, fix racy singleton structure (diff) | |
download | linux-54089d4cdc89732e65f968209d10aae542482c0c.tar.xz linux-54089d4cdc89732e65f968209d10aae542482c0c.zip |
TTY: srmcons, convert to use tty_port
This is needed because the tty buffer will become a tty_port member
later. That will help us to wipe out most of the races and checks for
the tty pointer in hot paths.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/alpha')
-rw-r--r-- | arch/alpha/kernel/srmcons.c | 32 |
1 files changed, 17 insertions, 15 deletions
diff --git a/arch/alpha/kernel/srmcons.c b/arch/alpha/kernel/srmcons.c index 2c89ce5c9ab6..3ea809430eda 100644 --- a/arch/alpha/kernel/srmcons.c +++ b/arch/alpha/kernel/srmcons.c @@ -30,9 +30,8 @@ static int srm_is_registered_console = 0; #define MAX_SRM_CONSOLE_DEVICES 1 /* only support 1 console device */ struct srmcons_private { - struct tty_struct *tty; + struct tty_port port; struct timer_list timer; - spinlock_t lock; } srmcons_singleton; typedef union _srmcons_result { @@ -68,20 +67,21 @@ static void srmcons_receive_chars(unsigned long data) { struct srmcons_private *srmconsp = (struct srmcons_private *)data; + struct tty_port *port = &srmconsp->port; unsigned long flags; int incr = 10; local_irq_save(flags); if (spin_trylock(&srmcons_callback_lock)) { - if (!srmcons_do_receive_chars(srmconsp->tty)) + if (!srmcons_do_receive_chars(port->tty)) incr = 100; spin_unlock(&srmcons_callback_lock); } - spin_lock(&srmconsp->lock); - if (srmconsp->tty) + spin_lock(&port->lock); + if (port->tty) mod_timer(&srmconsp->timer, jiffies + incr); - spin_unlock(&srmconsp->lock); + spin_unlock(&port->lock); local_irq_restore(flags); } @@ -157,18 +157,19 @@ static int srmcons_open(struct tty_struct *tty, struct file *filp) { struct srmcons_private *srmconsp = &srmcons_singleton; + struct tty_port *port = &srmconsp->port; unsigned long flags; - spin_lock_irqsave(&srmconsp->lock, flags); + spin_lock_irqsave(&port->lock, flags); - if (!srmconsp->tty) { + if (!port->tty) { tty->driver_data = srmconsp; - - srmconsp->tty = tty; + tty->port = port; + port->tty = tty; /* XXX proper refcounting */ mod_timer(&srmconsp->timer, jiffies + 10); } - spin_unlock_irqrestore(&srmconsp->lock, flags); + spin_unlock_irqrestore(&port->lock, flags); return 0; } @@ -177,16 +178,17 @@ static void srmcons_close(struct tty_struct *tty, struct file *filp) { struct srmcons_private *srmconsp = tty->driver_data; + struct tty_port *port = &srmconsp->port; unsigned long flags; - spin_lock_irqsave(&srmconsp->lock, flags); + spin_lock_irqsave(&port->lock, flags); if (tty->count == 1) { - srmconsp->tty = NULL; + port->tty = NULL; del_timer(&srmconsp->timer); } - spin_unlock_irqrestore(&srmconsp->lock, flags); + spin_unlock_irqrestore(&port->lock, flags); } @@ -203,7 +205,7 @@ static const struct tty_operations srmcons_ops = { static int __init srmcons_init(void) { - spin_lock_init(&srmcons_singleton.lock); + tty_port_init(&srmcons_singleton.port); setup_timer(&srmcons_singleton.timer, srmcons_receive_chars, (unsigned long)&srmcons_singleton); if (srm_is_registered_console) { |