Merge tag 'omap-devel-b-c-2-for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/pjw/omap-pending into devel-late

OMAP patches intended for the 3.7 merge window:

- Runtime PM conversions for the GPMC and RNG IP blocks
- Preparation patches for the OMAP common clock framework conversion
- clkdev alias additions required by other drivers
- Performance Monitoring Unit (PMU) support for OMAP2, 3, and non-4430 OMAP4
- OMAP hwmod code and data improvements
- Preparation patches for the IOMMU runtime PM conversion
- Preparation patches for OMAP4 full-chip retention support

Based on a merge of v3.6-rc6, the omap-cleanup-b-for-3.7 tag
(7852ec0536ca39cefffc6301dc77f8ae55592926),the cleanup-fixes-for-v3.7
tag (de6ca33a96a6bf61fcb91d3d399703e19ead9d1e), and the
omap-devel-am33xx-for-v3.7 tag
(11964f53eb4d9ce59a058be9999d9cfcb1ced878), due to dependencies.

These patches have been tested for meaningful warnings from
checkpatch, sparse, smatch, and cppcheck.  Basic build, boot[1], and
PM test logs are available here:

    http://www.pwsan.com/omap/testlogs/hwmod_prcm_clock_a_3.7/20120923173830/

...

1. Note that the N800 boot fails due to a known issue present in the
   base commit:

    http://www.spinics.net/lists/arm-kernel/msg196034.html

1 files changed, 56 insertions, 15 deletions

diff --git a/drivers/tty/tty_mutex.c b/drivers/tty/tty_mutex.c
index 9ff986c32a21..67feac9e6ebb 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);