diff options
author | Paul Walmsley <paul@pwsan.com> | 2012-09-22 10:00:11 -0600 |
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committer | Paul Walmsley <paul@pwsan.com> | 2012-09-22 10:00:11 -0600 |
commit | 5dbd6535d5bcb9d1899dd27d209ca651431df66b (patch) | |
tree | 137231cd0e8e01a30e4946625836d512db6830e7 /drivers/tty/tty_mutex.c | |
parent | 5698bd757d55b1bb87edd1a9744ab09c142abfc2 (diff) | |
parent | de6ca33a96a6bf61fcb91d3d399703e19ead9d1e (diff) |
Merge tag 'cleanup-fixes-for-v3.7' into test_v3.6-rc6_cff3.7_odaf3.7
These fixes are needed to fix non-omap build breakage for
twl-core driver and to fix omap1_defconfig compile when
led driver changes and omap sparse IRQ changes are merged
together. Also fix warnings for omaps not using pinctrl
framework yet.
Diffstat (limited to 'drivers/tty/tty_mutex.c')
-rw-r--r-- | drivers/tty/tty_mutex.c | 71 |
1 files changed, 56 insertions, 15 deletions
diff --git a/drivers/tty/tty_mutex.c b/drivers/tty/tty_mutex.c index 9ff986c32a2..67feac9e6eb 100644 --- a/drivers/tty/tty_mutex.c +++ b/drivers/tty/tty_mutex.c @@ -4,29 +4,70 @@ #include <linux/semaphore.h> #include <linux/sched.h> -/* - * The 'big tty mutex' - * - * This mutex is taken and released by tty_lock() and tty_unlock(), - * replacing the older big kernel lock. - * It can no longer be taken recursively, and does not get - * released implicitly while sleeping. - * - * Don't use in new code. - */ -static DEFINE_MUTEX(big_tty_mutex); +/* Legacy tty mutex glue */ + +enum { + TTY_MUTEX_NORMAL, + TTY_MUTEX_NESTED, +}; /* * Getting the big tty mutex. */ -void __lockfunc tty_lock(void) + +static void __lockfunc tty_lock_nested(struct tty_struct *tty, + unsigned int subclass) { - mutex_lock(&big_tty_mutex); + if (tty->magic != TTY_MAGIC) { + printk(KERN_ERR "L Bad %p\n", tty); + WARN_ON(1); + return; + } + tty_kref_get(tty); + mutex_lock_nested(&tty->legacy_mutex, subclass); +} + +void __lockfunc tty_lock(struct tty_struct *tty) +{ + return tty_lock_nested(tty, TTY_MUTEX_NORMAL); } EXPORT_SYMBOL(tty_lock); -void __lockfunc tty_unlock(void) +void __lockfunc tty_unlock(struct tty_struct *tty) { - mutex_unlock(&big_tty_mutex); + if (tty->magic != TTY_MAGIC) { + printk(KERN_ERR "U Bad %p\n", tty); + WARN_ON(1); + return; + } + mutex_unlock(&tty->legacy_mutex); + tty_kref_put(tty); } EXPORT_SYMBOL(tty_unlock); + +/* + * Getting the big tty mutex for a pair of ttys with lock ordering + * On a non pty/tty pair tty2 can be NULL which is just fine. + */ +void __lockfunc tty_lock_pair(struct tty_struct *tty, + struct tty_struct *tty2) +{ + if (tty < tty2) { + tty_lock(tty); + tty_lock_nested(tty2, TTY_MUTEX_NESTED); + } else { + if (tty2 && tty2 != tty) + tty_lock(tty2); + tty_lock_nested(tty, TTY_MUTEX_NESTED); + } +} +EXPORT_SYMBOL(tty_lock_pair); + +void __lockfunc tty_unlock_pair(struct tty_struct *tty, + struct tty_struct *tty2) +{ + tty_unlock(tty); + if (tty2 && tty2 != tty) + tty_unlock(tty2); +} +EXPORT_SYMBOL(tty_unlock_pair); |