BKL: That's all, folks

This removes the implementation of the big kernel lock,
at last. A lot of people have worked on this in the
past, I so the credit for this patch should be with
everyone who participated in the hunt.

The names on the Cc list are the people that were the
most active in this, according to the recorded git
history, in alphabetical order.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Alan Cox <alan@linux.intel.com>
Cc: Alessio Igor Bogani <abogani@texware.it>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Hendry <andrew.hendry@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Hans Verkuil <hverkuil@xs4all.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Jan Blunck <jblunck@infradead.org>
Cc: John Kacur <jkacur@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Oliver Neukum <oliver@neukum.org>
Cc: Paul Menage <menage@google.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 1 insertions, 73 deletions

diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index 32f9fd6..ba36217 100644
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -93,13 +93,6 @@
  */
 #define in_nmi()	(preempt_count() & NMI_MASK)
 
-#if defined(CONFIG_PREEMPT) && defined(CONFIG_BKL)
-# include <linux/sched.h>
-# define PREEMPT_INATOMIC_BASE (current->lock_depth >= 0)
-#else
-# define PREEMPT_INATOMIC_BASE 0
-#endif
-
 #if defined(CONFIG_PREEMPT)
 # define PREEMPT_CHECK_OFFSET 1
 #else
@@ -113,7 +106,7 @@
  * used in the general case to determine whether sleeping is possible.
  * Do not use in_atomic() in driver code.
  */
-#define in_atomic()	((preempt_count() & ~PREEMPT_ACTIVE) != PREEMPT_INATOMIC_BASE)
+#define in_atomic()	((preempt_count() & ~PREEMPT_ACTIVE) != 0)
 
 /*
  * Check whether we were atomic before we did preempt_disable():
diff --git a/include/linux/smp_lock.h b/include/linux/smp_lock.h
deleted file mode 100644
index 3a19882..0000000
--- a/include/linux/smp_lock.h
+++ /dev/null
@@ -1,65 +0,0 @@
-#ifndef __LINUX_SMPLOCK_H
-#define __LINUX_SMPLOCK_H
-
-#ifdef CONFIG_LOCK_KERNEL
-#include <linux/sched.h>
-
-extern int __lockfunc __reacquire_kernel_lock(void);
-extern void __lockfunc __release_kernel_lock(void);
-
-/*
- * Release/re-acquire global kernel lock for the scheduler
- */
-#define release_kernel_lock(tsk) do { 		\
-	if (unlikely((tsk)->lock_depth >= 0))	\
-		__release_kernel_lock();	\
-} while (0)
-
-static inline int reacquire_kernel_lock(struct task_struct *task)
-{
-	if (unlikely(task->lock_depth >= 0))
-		return __reacquire_kernel_lock();
-	return 0;
-}
-
-extern void __lockfunc
-_lock_kernel(const char *func, const char *file, int line)
-__acquires(kernel_lock);
-
-extern void __lockfunc
-_unlock_kernel(const char *func, const char *file, int line)
-__releases(kernel_lock);
-
-#define lock_kernel() do {					\
-	_lock_kernel(__func__, __FILE__, __LINE__);		\
-} while (0)
-
-#define unlock_kernel()	do {					\
-	_unlock_kernel(__func__, __FILE__, __LINE__);		\
-} while (0)
-
-/*
- * Various legacy drivers don't really need the BKL in a specific
- * function, but they *do* need to know that the BKL became available.
- * This function just avoids wrapping a bunch of lock/unlock pairs
- * around code which doesn't really need it.
- */
-static inline void cycle_kernel_lock(void)
-{
-	lock_kernel();
-	unlock_kernel();
-}
-
-#else
-
-#ifdef CONFIG_BKL /* provoke build bug if not set */
-#define lock_kernel()
-#define unlock_kernel()
-#define cycle_kernel_lock()			do { } while(0)
-#endif /* CONFIG_BKL */
-
-#define release_kernel_lock(task)		do { } while(0)
-#define reacquire_kernel_lock(task)		0
-
-#endif /* CONFIG_LOCK_KERNEL */
-#endif /* __LINUX_SMPLOCK_H */