7 files changed, 2 insertions, 232 deletions

diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index 32f9fd6619b4..ba362171e8ae 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 3a1988202731..000000000000
--- 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 */
diff --git a/init/Kconfig b/init/Kconfig
index be788c0957d4..a88d1c919a4d 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -69,11 +69,6 @@ config BROKEN_ON_SMP
         depends on BROKEN || !SMP
         default y
 
-config LOCK_KERNEL
-        bool
-        depends on (SMP || PREEMPT) && BKL
-        default y
-
 config INIT_ENV_ARG_LIMIT
         int
         default 32 if !UML
diff --git a/kernel/sched.c b/kernel/sched.c
index 18d38e4ec7ba..827c170c6017 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -32,7 +32,6 @@
 #include <linux/init.h>
 #include <linux/uaccess.h>
 #include <linux/highmem.h>
-#include <linux/smp_lock.h>
 #include <asm/mmu_context.h>
 #include <linux/interrupt.h>
 #include <linux/capability.h>
@@ -3945,9 +3944,6 @@ need_resched:
         rcu_note_context_switch(cpu);
         prev = rq->curr;
 
-        release_kernel_lock(prev);
-need_resched_nonpreemptible:
-
         schedule_debug(prev);
 
         if (sched_feat(HRTICK))
@@ -4010,9 +4006,6 @@ need_resched_nonpreemptible:
 
         post_schedule(rq);
 
-        if (unlikely(reacquire_kernel_lock(prev)))
-                goto need_resched_nonpreemptible;
-
         preempt_enable_no_resched();
         if (need_resched())
                 goto need_resched;
@@ -8074,7 +8067,7 @@ static inline int preempt_count_equals(int preempt_offset)
 {
         int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth();
 
-        return (nested == PREEMPT_INATOMIC_BASE + preempt_offset);
+        return (nested == preempt_offset);
 }
 
 void __might_sleep(const char *file, int line, int preempt_offset)
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 2b97418c67e2..6f440d82b58d 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -470,15 +470,6 @@ config DEBUG_MUTEXES
          This feature allows mutex semantics violations to be detected and
          reported.
 
-config BKL
-        bool "Big Kernel Lock" if (SMP || PREEMPT)
-        default y
-        help
-          This is the traditional lock that is used in old code instead
-          of proper locking. All drivers that use the BKL should depend
-          on this symbol.
-          Say Y here unless you are working on removing the BKL.
-
 config DEBUG_LOCK_ALLOC
         bool "Lock debugging: detect incorrect freeing of live locks"
         depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
diff --git a/lib/Makefile b/lib/Makefile
index cbb774f7d41d..de6c609bb4e4 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -43,7 +43,6 @@ obj-$(CONFIG_GENERIC_FIND_LAST_BIT) += find_last_bit.o
 CFLAGS_hweight.o = $(subst $(quote),,$(CONFIG_ARCH_HWEIGHT_CFLAGS))
 obj-$(CONFIG_GENERIC_HWEIGHT) += hweight.o
 
-obj-$(CONFIG_LOCK_KERNEL) += kernel_lock.o
 obj-$(CONFIG_BTREE) += btree.o
 obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o
 obj-$(CONFIG_DEBUG_LIST) += list_debug.o
diff --git a/lib/kernel_lock.c b/lib/kernel_lock.c
deleted file mode 100644
index d80e12265862..000000000000
--- a/lib/kernel_lock.c
+++ /dev/null
@@ -1,136 +0,0 @@
-/*
- * lib/kernel_lock.c
- *
- * This is the traditional BKL - big kernel lock. Largely
- * relegated to obsolescence, but used by various less
- * important (or lazy) subsystems.
- */
-#include <linux/module.h>
-#include <linux/kallsyms.h>
-#include <linux/semaphore.h>
-#include <linux/smp_lock.h>
-
-/*
- * The 'big kernel lock'
- *
- * This spinlock is taken and released recursively by lock_kernel()
- * and unlock_kernel().  It is transparently dropped and reacquired
- * over schedule().  It is used to protect legacy code that hasn't
- * been migrated to a proper locking design yet.
- *
- * Don't use in new code.
- */
-static  __cacheline_aligned_in_smp DEFINE_RAW_SPINLOCK(kernel_flag);
-
-
-/*
- * Acquire/release the underlying lock from the scheduler.
- *
- * This is called with preemption disabled, and should
- * return an error value if it cannot get the lock and
- * TIF_NEED_RESCHED gets set.
- *
- * If it successfully gets the lock, it should increment
- * the preemption count like any spinlock does.
- *
- * (This works on UP too - do_raw_spin_trylock will never
- * return false in that case)
- */
-int __lockfunc __reacquire_kernel_lock(void)
-{
-        while (!do_raw_spin_trylock(&kernel_flag)) {
-                if (need_resched())
-                        return -EAGAIN;
-                cpu_relax();
-        }
-        preempt_disable();
-        return 0;
-}
-
-void __lockfunc __release_kernel_lock(void)
-{
-        do_raw_spin_unlock(&kernel_flag);
-        preempt_enable_no_resched();
-}
-
-/*
- * These are the BKL spinlocks - we try to be polite about preemption.
- * If SMP is not on (ie UP preemption), this all goes away because the
- * do_raw_spin_trylock() will always succeed.
- */
-#ifdef CONFIG_PREEMPT
-static inline void __lock_kernel(void)
-{
-        preempt_disable();
-        if (unlikely(!do_raw_spin_trylock(&kernel_flag))) {
-                /*
-                 * If preemption was disabled even before this
-                 * was called, there's nothing we can be polite
-                 * about - just spin.
-                 */
-                if (preempt_count() > 1) {
-                        do_raw_spin_lock(&kernel_flag);
-                        return;
-                }
-
-                /*
-                 * Otherwise, let's wait for the kernel lock
-                 * with preemption enabled..
-                 */
-                do {
-                        preempt_enable();
-                        while (raw_spin_is_locked(&kernel_flag))
-                                cpu_relax();
-                        preempt_disable();
-                } while (!do_raw_spin_trylock(&kernel_flag));
-        }
-}
-
-#else
-
-/*
- * Non-preemption case - just get the spinlock
- */
-static inline void __lock_kernel(void)
-{
-        do_raw_spin_lock(&kernel_flag);
-}
-#endif
-
-static inline void __unlock_kernel(void)
-{
-        /*
-         * the BKL is not covered by lockdep, so we open-code the
-         * unlocking sequence (and thus avoid the dep-chain ops):
-         */
-        do_raw_spin_unlock(&kernel_flag);
-        preempt_enable();
-}
-
-/*
- * Getting the big kernel lock.
- *
- * This cannot happen asynchronously, so we only need to
- * worry about other CPU's.
- */
-void __lockfunc _lock_kernel(const char *func, const char *file, int line)
-{
-        int depth = current->lock_depth + 1;
-
-        if (likely(!depth)) {
-                might_sleep();
-                __lock_kernel();
-        }
-        current->lock_depth = depth;
-}
-
-void __lockfunc _unlock_kernel(const char *func, const char *file, int line)
-{
-        BUG_ON(current->lock_depth < 0);
-        if (likely(--current->lock_depth < 0))
-                __unlock_kernel();
-}
-
-EXPORT_SYMBOL(_lock_kernel);
-EXPORT_SYMBOL(_unlock_kernel);
-