[PATCH] spinlock consolidation

This patch (written by me and also containing many suggestions of Arjan van
de Ven) does a major cleanup of the spinlock code.  It does the following
things:

 - consolidates and enhances the spinlock/rwlock debugging code

 - simplifies the asm/spinlock.h files

 - encapsulates the raw spinlock type and moves generic spinlock
   features (such as ->break_lock) into the generic code.

 - cleans up the spinlock code hierarchy to get rid of the spaghetti.

Most notably there's now only a single variant of the debugging code,
located in lib/spinlock_debug.c.  (previously we had one SMP debugging
variant per architecture, plus a separate generic one for UP builds)

Also, i've enhanced the rwlock debugging facility, it will now track
write-owners.  There is new spinlock-owner/CPU-tracking on SMP builds too.
All locks have lockup detection now, which will work for both soft and hard
spin/rwlock lockups.

The arch-level include files now only contain the minimally necessary
subset of the spinlock code - all the rest that can be generalized now
lives in the generic headers:

 include/asm-i386/spinlock_types.h       |   16
 include/asm-x86_64/spinlock_types.h     |   16

I have also split up the various spinlock variants into separate files,
making it easier to see which does what. The new layout is:

   SMP                         |  UP
   ----------------------------|-----------------------------------
   asm/spinlock_types_smp.h    |  linux/spinlock_types_up.h
   linux/spinlock_types.h      |  linux/spinlock_types.h
   asm/spinlock_smp.h          |  linux/spinlock_up.h
   linux/spinlock_api_smp.h    |  linux/spinlock_api_up.h
   linux/spinlock.h            |  linux/spinlock.h

/*
 * here's the role of the various spinlock/rwlock related include files:
 *
 * on SMP builds:
 *
 *  asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the
 *                        initializers
 *
 *  linux/spinlock_types.h:
 *                        defines the generic type and initializers
 *
 *  asm/spinlock.h:       contains the __raw_spin_*()/etc. lowlevel
 *                        implementations, mostly inline assembly code
 *
 *   (also included on UP-debug builds:)
 *
 *  linux/spinlock_api_smp.h:
 *                        contains the prototypes for the _spin_*() APIs.
 *
 *  linux/spinlock.h:     builds the final spin_*() APIs.
 *
 * on UP builds:
 *
 *  linux/spinlock_type_up.h:
 *                        contains the generic, simplified UP spinlock type.
 *                        (which is an empty structure on non-debug builds)
 *
 *  linux/spinlock_types.h:
 *                        defines the generic type and initializers
 *
 *  linux/spinlock_up.h:
 *                        contains the __raw_spin_*()/etc. version of UP
 *                        builds. (which are NOPs on non-debug, non-preempt
 *                        builds)
 *
 *   (included on UP-non-debug builds:)
 *
 *  linux/spinlock_api_up.h:
 *                        builds the _spin_*() APIs.
 *
 *  linux/spinlock.h:     builds the final spin_*() APIs.
 */

All SMP and UP architectures are converted by this patch.

arm, i386, ia64, ppc, ppc64, s390/s390x, x64 was build-tested via
crosscompilers.  m32r, mips, sh, sparc, have not been tested yet, but should
be mostly fine.

From: Grant Grundler <grundler@parisc-linux.org>

  Booted and lightly tested on a500-44 (64-bit, SMP kernel, dual CPU).
  Builds 32-bit SMP kernel (not booted or tested).  I did not try to build
  non-SMP kernels.  That should be trivial to fix up later if necessary.

  I converted bit ops atomic_hash lock to raw_spinlock_t.  Doing so avoids
  some ugly nesting of linux/*.h and asm/*.h files.  Those particular locks
  are well tested and contained entirely inside arch specific code.  I do NOT
  expect any new issues to arise with them.

 If someone does ever need to use debug/metrics with them, then they will
  need to unravel this hairball between spinlocks, atomic ops, and bit ops
  that exist only because parisc has exactly one atomic instruction: LDCW
  (load and clear word).

From: "Luck, Tony" <tony.luck@intel.com>

   ia64 fix

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjanv@infradead.org>
Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Cc: Matthew Wilcox <willy@debian.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Mikael Pettersson <mikpe@csd.uu.se>
Signed-off-by: Benoit Boissinot <benoit.boissinot@ens-lyon.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 125 insertions, 502 deletions

diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index d6ba068719b6..cdc99a27840d 100644
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -2,7 +2,48 @@
 #define __LINUX_SPINLOCK_H
 
 /*
- * include/linux/spinlock.h - generic locking declarations
+ * include/linux/spinlock.h - generic spinlock/rwlock declarations
+ *
+ * here's the role of the various spinlock/rwlock related include files:
+ *
+ * on SMP builds:
+ *
+ *  asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the
+ *                        initializers
+ *
+ *  linux/spinlock_types.h:
+ *                        defines the generic type and initializers
+ *
+ *  asm/spinlock.h:       contains the __raw_spin_*()/etc. lowlevel
+ *                        implementations, mostly inline assembly code
+ *
+ *   (also included on UP-debug builds:)
+ *
+ *  linux/spinlock_api_smp.h:
+ *                        contains the prototypes for the _spin_*() APIs.
+ *
+ *  linux/spinlock.h:     builds the final spin_*() APIs.
+ *
+ * on UP builds:
+ *
+ *  linux/spinlock_type_up.h:
+ *                        contains the generic, simplified UP spinlock type.
+ *                        (which is an empty structure on non-debug builds)
+ *
+ *  linux/spinlock_types.h:
+ *                        defines the generic type and initializers
+ *
+ *  linux/spinlock_up.h:
+ *                        contains the __raw_spin_*()/etc. version of UP
+ *                        builds. (which are NOPs on non-debug, non-preempt
+ *                        builds)
+ *
+ *   (included on UP-non-debug builds:)
+ *
+ *  linux/spinlock_api_up.h:
+ *                        builds the _spin_*() APIs.
+ *
+ *  linux/spinlock.h:     builds the final spin_*() APIs.
  */
 
 #include <linux/config.h>
@@ -13,7 +54,6 @@
 #include <linux/kernel.h>
 #include <linux/stringify.h>
 
-#include <asm/processor.h>	/* for cpu relax */
 #include <asm/system.h>
 
 /*
@@ -35,423 +75,84 @@
 #define __lockfunc fastcall __attribute__((section(".spinlock.text")))
 
 /*
- * If CONFIG_SMP is set, pull in the _raw_* definitions
+ * Pull the raw_spinlock_t and raw_rwlock_t definitions:
  */
-#ifdef CONFIG_SMP
-
-#define assert_spin_locked(x)	BUG_ON(!spin_is_locked(x))
-#include <asm/spinlock.h>
-
-int __lockfunc _spin_trylock(spinlock_t *lock);
-int __lockfunc _read_trylock(rwlock_t *lock);
-int __lockfunc _write_trylock(rwlock_t *lock);
-
-void __lockfunc _spin_lock(spinlock_t *lock)	__acquires(spinlock_t);
-void __lockfunc _read_lock(rwlock_t *lock)	__acquires(rwlock_t);
-void __lockfunc _write_lock(rwlock_t *lock)	__acquires(rwlock_t);
-
-void __lockfunc _spin_unlock(spinlock_t *lock)	__releases(spinlock_t);
-void __lockfunc _read_unlock(rwlock_t *lock)	__releases(rwlock_t);
-void __lockfunc _write_unlock(rwlock_t *lock)	__releases(rwlock_t);
-
-unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock)	__acquires(spinlock_t);
-unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock)	__acquires(rwlock_t);
-unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock)	__acquires(rwlock_t);
-
-void __lockfunc _spin_lock_irq(spinlock_t *lock)	__acquires(spinlock_t);
-void __lockfunc _spin_lock_bh(spinlock_t *lock)		__acquires(spinlock_t);
-void __lockfunc _read_lock_irq(rwlock_t *lock)		__acquires(rwlock_t);
-void __lockfunc _read_lock_bh(rwlock_t *lock)		__acquires(rwlock_t);
-void __lockfunc _write_lock_irq(rwlock_t *lock)		__acquires(rwlock_t);
-void __lockfunc _write_lock_bh(rwlock_t *lock)		__acquires(rwlock_t);
-
-void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)	__releases(spinlock_t);
-void __lockfunc _spin_unlock_irq(spinlock_t *lock)				__releases(spinlock_t);
-void __lockfunc _spin_unlock_bh(spinlock_t *lock)				__releases(spinlock_t);
-void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)	__releases(rwlock_t);
-void __lockfunc _read_unlock_irq(rwlock_t *lock)				__releases(rwlock_t);
-void __lockfunc _read_unlock_bh(rwlock_t *lock)					__releases(rwlock_t);
-void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)	__releases(rwlock_t);
-void __lockfunc _write_unlock_irq(rwlock_t *lock)				__releases(rwlock_t);
-void __lockfunc _write_unlock_bh(rwlock_t *lock)				__releases(rwlock_t);
-
-int __lockfunc _spin_trylock_bh(spinlock_t *lock);
-int __lockfunc generic_raw_read_trylock(rwlock_t *lock);
-int in_lock_functions(unsigned long addr);
-
-#else
+#include <linux/spinlock_types.h>
 
-#define in_lock_functions(ADDR) 0
+extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock);
 
-#if !defined(CONFIG_PREEMPT) && !defined(CONFIG_DEBUG_SPINLOCK)
-# define _atomic_dec_and_lock(atomic,lock) atomic_dec_and_test(atomic)
-# define ATOMIC_DEC_AND_LOCK
-#endif
-
-#ifdef CONFIG_DEBUG_SPINLOCK
- 
-#define SPINLOCK_MAGIC	0x1D244B3C
-typedef struct {
-	unsigned long magic;
-	volatile unsigned long lock;
-	volatile unsigned int babble;
-	const char *module;
-	char *owner;
-	int oline;
-} spinlock_t;
-#define SPIN_LOCK_UNLOCKED (spinlock_t) { SPINLOCK_MAGIC, 0, 10, __FILE__ , NULL, 0}
-
-#define spin_lock_init(x) \
-	do { \
-		(x)->magic = SPINLOCK_MAGIC; \
-		(x)->lock = 0; \
-		(x)->babble = 5; \
-		(x)->module = __FILE__; \
-		(x)->owner = NULL; \
-		(x)->oline = 0; \
-	} while (0)
-
-#define CHECK_LOCK(x) \
-	do { \
-	 	if ((x)->magic != SPINLOCK_MAGIC) { \
-			printk(KERN_ERR "%s:%d: spin_is_locked on uninitialized spinlock %p.\n", \
-					__FILE__, __LINE__, (x)); \
-		} \
-	} while(0)
-
-#define _raw_spin_lock(x)		\
-	do { \
-	 	CHECK_LOCK(x); \
-		if ((x)->lock&&(x)->babble) { \
-			(x)->babble--; \
-			printk("%s:%d: spin_lock(%s:%p) already locked by %s/%d\n", \
-					__FILE__,__LINE__, (x)->module, \
-					(x), (x)->owner, (x)->oline); \
-		} \
-		(x)->lock = 1; \
-		(x)->owner = __FILE__; \
-		(x)->oline = __LINE__; \
-	} while (0)
-
-/* without debugging, spin_is_locked on UP always says
- * FALSE. --> printk if already locked. */
-#define spin_is_locked(x) \
-	({ \
-	 	CHECK_LOCK(x); \
-		if ((x)->lock&&(x)->babble) { \
-			(x)->babble--; \
-			printk("%s:%d: spin_is_locked(%s:%p) already locked by %s/%d\n", \
-					__FILE__,__LINE__, (x)->module, \
-					(x), (x)->owner, (x)->oline); \
-		} \
-		0; \
-	})
-
-/* with debugging, assert_spin_locked() on UP does check
- * the lock value properly */
-#define assert_spin_locked(x) \
-	({ \
-		CHECK_LOCK(x); \
-		BUG_ON(!(x)->lock); \
-	})
-
-/* without debugging, spin_trylock on UP always says
- * TRUE. --> printk if already locked. */
-#define _raw_spin_trylock(x) \
-	({ \
-	 	CHECK_LOCK(x); \
-		if ((x)->lock&&(x)->babble) { \
-			(x)->babble--; \
-			printk("%s:%d: spin_trylock(%s:%p) already locked by %s/%d\n", \
-					__FILE__,__LINE__, (x)->module, \
-					(x), (x)->owner, (x)->oline); \
-		} \
-		(x)->lock = 1; \
-		(x)->owner = __FILE__; \
-		(x)->oline = __LINE__; \
-		1; \
-	})
-
-#define spin_unlock_wait(x)	\
-	do { \
-	 	CHECK_LOCK(x); \
-		if ((x)->lock&&(x)->babble) { \
-			(x)->babble--; \
-			printk("%s:%d: spin_unlock_wait(%s:%p) owned by %s/%d\n", \
-					__FILE__,__LINE__, (x)->module, (x), \
-					(x)->owner, (x)->oline); \
-		}\
-	} while (0)
-
-#define _raw_spin_unlock(x) \
-	do { \
-	 	CHECK_LOCK(x); \
-		if (!(x)->lock&&(x)->babble) { \
-			(x)->babble--; \
-			printk("%s:%d: spin_unlock(%s:%p) not locked\n", \
-					__FILE__,__LINE__, (x)->module, (x));\
-		} \
-		(x)->lock = 0; \
-	} while (0)
-#else
 /*
- * gcc versions before ~2.95 have a nasty bug with empty initializers.
+ * Pull the __raw*() functions/declarations (UP-nondebug doesnt need them):
  */
-#if (__GNUC__ > 2)
-  typedef struct { } spinlock_t;
-  #define SPIN_LOCK_UNLOCKED (spinlock_t) { }
+#if defined(CONFIG_SMP)
+# include <asm/spinlock.h>
 #else
-  typedef struct { int gcc_is_buggy; } spinlock_t;
-  #define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 }
+# include <linux/spinlock_up.h>
 #endif
 
+#define spin_lock_init(lock)	do { *(lock) = SPIN_LOCK_UNLOCKED; } while (0)
+#define rwlock_init(lock)	do { *(lock) = RW_LOCK_UNLOCKED; } while (0)
+
+#define spin_is_locked(lock)	__raw_spin_is_locked(&(lock)->raw_lock)
+
+/**
+ * spin_unlock_wait - wait until the spinlock gets unlocked
+ * @lock: the spinlock in question.
+ */
+#define spin_unlock_wait(lock)	__raw_spin_unlock_wait(&(lock)->raw_lock)
+
 /*
- * If CONFIG_SMP is unset, declare the _raw_* definitions as nops
+ * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
  */
-#define spin_lock_init(lock)	do { (void)(lock); } while(0)
-#define _raw_spin_lock(lock)	do { (void)(lock); } while(0)
-#define spin_is_locked(lock)	((void)(lock), 0)
-#define assert_spin_locked(lock)	do { (void)(lock); } while(0)
-#define _raw_spin_trylock(lock)	(((void)(lock), 1))
-#define spin_unlock_wait(lock)	(void)(lock)
-#define _raw_spin_unlock(lock) do { (void)(lock); } while(0)
-#endif /* CONFIG_DEBUG_SPINLOCK */
-
-/* RW spinlocks: No debug version */
-
-#if (__GNUC__ > 2)
-  typedef struct { } rwlock_t;
-  #define RW_LOCK_UNLOCKED (rwlock_t) { }
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+# include <linux/spinlock_api_smp.h>
 #else
-  typedef struct { int gcc_is_buggy; } rwlock_t;
-  #define RW_LOCK_UNLOCKED (rwlock_t) { 0 }
+# include <linux/spinlock_api_up.h>
 #endif
 
-#define rwlock_init(lock)	do { (void)(lock); } while(0)
-#define _raw_read_lock(lock)	do { (void)(lock); } while(0)
-#define _raw_read_unlock(lock)	do { (void)(lock); } while(0)
-#define _raw_write_lock(lock)	do { (void)(lock); } while(0)
-#define _raw_write_unlock(lock)	do { (void)(lock); } while(0)
-#define read_can_lock(lock)	(((void)(lock), 1))
-#define write_can_lock(lock)	(((void)(lock), 1))
-#define _raw_read_trylock(lock) ({ (void)(lock); (1); })
-#define _raw_write_trylock(lock) ({ (void)(lock); (1); })
-
-#define _spin_trylock(lock)	({preempt_disable(); _raw_spin_trylock(lock) ? \
-				1 : ({preempt_enable(); 0;});})
-
-#define _read_trylock(lock)	({preempt_disable();_raw_read_trylock(lock) ? \
-				1 : ({preempt_enable(); 0;});})
-
-#define _write_trylock(lock)	({preempt_disable(); _raw_write_trylock(lock) ? \
-				1 : ({preempt_enable(); 0;});})
-
-#define _spin_trylock_bh(lock)	({preempt_disable(); local_bh_disable(); \
-				_raw_spin_trylock(lock) ? \
-				1 : ({preempt_enable_no_resched(); local_bh_enable(); 0;});})
-
-#define _spin_lock(lock)	\
-do { \
-	preempt_disable(); \
-	_raw_spin_lock(lock); \
-	__acquire(lock); \
-} while(0)
-
-#define _write_lock(lock) \
-do { \
-	preempt_disable(); \
-	_raw_write_lock(lock); \
-	__acquire(lock); \
-} while(0)
- 
-#define _read_lock(lock)	\
-do { \
-	preempt_disable(); \
-	_raw_read_lock(lock); \
-	__acquire(lock); \
-} while(0)
-
-#define _spin_unlock(lock) \
-do { \
-	_raw_spin_unlock(lock); \
-	preempt_enable(); \
-	__release(lock); \
-} while (0)
-
-#define _write_unlock(lock) \
-do { \
-	_raw_write_unlock(lock); \
-	preempt_enable(); \
-	__release(lock); \
-} while(0)
-
-#define _read_unlock(lock) \
-do { \
-	_raw_read_unlock(lock); \
-	preempt_enable(); \
-	__release(lock); \
-} while(0)
-
-#define _spin_lock_irqsave(lock, flags) \
-do {	\
-	local_irq_save(flags); \
-	preempt_disable(); \
-	_raw_spin_lock(lock); \
-	__acquire(lock); \
-} while (0)
-
-#define _spin_lock_irq(lock) \
-do { \
-	local_irq_disable(); \
-	preempt_disable(); \
-	_raw_spin_lock(lock); \
-	__acquire(lock); \
-} while (0)
-
-#define _spin_lock_bh(lock) \
-do { \
-	local_bh_disable(); \
-	preempt_disable(); \
-	_raw_spin_lock(lock); \
-	__acquire(lock); \
-} while (0)
-
-#define _read_lock_irqsave(lock, flags) \
-do {	\
-	local_irq_save(flags); \
-	preempt_disable(); \
-	_raw_read_lock(lock); \
-	__acquire(lock); \
-} while (0)
-
-#define _read_lock_irq(lock) \
-do { \
-	local_irq_disable(); \
-	preempt_disable(); \
-	_raw_read_lock(lock); \
-	__acquire(lock); \
-} while (0)
-
-#define _read_lock_bh(lock) \
-do { \
-	local_bh_disable(); \
-	preempt_disable(); \
-	_raw_read_lock(lock); \
-	__acquire(lock); \
-} while (0)
-
-#define _write_lock_irqsave(lock, flags) \
-do {	\
-	local_irq_save(flags); \
-	preempt_disable(); \
-	_raw_write_lock(lock); \
-	__acquire(lock); \
-} while (0)
+#ifdef CONFIG_DEBUG_SPINLOCK
+ extern void _raw_spin_lock(spinlock_t *lock);
+#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
+ extern int _raw_spin_trylock(spinlock_t *lock);
+ extern void _raw_spin_unlock(spinlock_t *lock);
+
+ extern void _raw_read_lock(rwlock_t *lock);
+ extern int _raw_read_trylock(rwlock_t *lock);
+ extern void _raw_read_unlock(rwlock_t *lock);
+ extern void _raw_write_lock(rwlock_t *lock);
+ extern int _raw_write_trylock(rwlock_t *lock);
+ extern void _raw_write_unlock(rwlock_t *lock);
+#else
+# define _raw_spin_unlock(lock)		__raw_spin_unlock(&(lock)->raw_lock)
+# define _raw_spin_trylock(lock)	__raw_spin_trylock(&(lock)->raw_lock)
+# define _raw_spin_lock(lock)		__raw_spin_lock(&(lock)->raw_lock)
+# define _raw_spin_lock_flags(lock, flags) \
+		__raw_spin_lock_flags(&(lock)->raw_lock, *(flags))
+# define _raw_read_lock(rwlock)		__raw_read_lock(&(rwlock)->raw_lock)
+# define _raw_write_lock(rwlock)	__raw_write_lock(&(rwlock)->raw_lock)
+# define _raw_read_unlock(rwlock)	__raw_read_unlock(&(rwlock)->raw_lock)
+# define _raw_write_unlock(rwlock)	__raw_write_unlock(&(rwlock)->raw_lock)
+# define _raw_read_trylock(rwlock)	__raw_read_trylock(&(rwlock)->raw_lock)
+# define _raw_write_trylock(rwlock)	__raw_write_trylock(&(rwlock)->raw_lock)
+#endif
 
-#define _write_lock_irq(lock) \
-do { \
-	local_irq_disable(); \
-	preempt_disable(); \
-	_raw_write_lock(lock); \
-	__acquire(lock); \
-} while (0)
-
-#define _write_lock_bh(lock) \
-do { \
-	local_bh_disable(); \
-	preempt_disable(); \
-	_raw_write_lock(lock); \
-	__acquire(lock); \
-} while (0)
-
-#define _spin_unlock_irqrestore(lock, flags) \
-do { \
-	_raw_spin_unlock(lock); \
-	local_irq_restore(flags); \
-	preempt_enable(); \
-	__release(lock); \
-} while (0)
-
-#define _spin_unlock_irq(lock) \
-do { \
-	_raw_spin_unlock(lock); \
-	local_irq_enable(); \
-	preempt_enable(); \
-	__release(lock); \
-} while (0)
-
-#define _spin_unlock_bh(lock) \
-do { \
-	_raw_spin_unlock(lock); \
-	preempt_enable_no_resched(); \
-	local_bh_enable(); \
-	__release(lock); \
-} while (0)
-
-#define _write_unlock_bh(lock) \
-do { \
-	_raw_write_unlock(lock); \
-	preempt_enable_no_resched(); \
-	local_bh_enable(); \
-	__release(lock); \
-} while (0)
-
-#define _read_unlock_irqrestore(lock, flags) \
-do { \
-	_raw_read_unlock(lock); \
-	local_irq_restore(flags); \
-	preempt_enable(); \
-	__release(lock); \
-} while (0)
-
-#define _write_unlock_irqrestore(lock, flags) \
-do { \
-	_raw_write_unlock(lock); \
-	local_irq_restore(flags); \
-	preempt_enable(); \
-	__release(lock); \
-} while (0)
-
-#define _read_unlock_irq(lock)	\
-do { \
-	_raw_read_unlock(lock);	\
-	local_irq_enable();	\
-	preempt_enable();	\
-	__release(lock); \
-} while (0)
-
-#define _read_unlock_bh(lock)	\
-do { \
-	_raw_read_unlock(lock);	\
-	preempt_enable_no_resched();	\
-	local_bh_enable();	\
-	__release(lock); \
-} while (0)
-
-#define _write_unlock_irq(lock)	\
-do { \
-	_raw_write_unlock(lock);	\
-	local_irq_enable();	\
-	preempt_enable();	\
-	__release(lock); \
-} while (0)
-
-#endif /* !SMP */
+#define read_can_lock(rwlock)		__raw_read_can_lock(&(rwlock)->raw_lock)
+#define write_can_lock(rwlock)		__raw_write_can_lock(&(rwlock)->raw_lock)
 
 /*
  * Define the various spin_lock and rw_lock methods.  Note we define these
  * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various
  * methods are defined as nops in the case they are not required.
  */
-#define spin_trylock(lock)	__cond_lock(_spin_trylock(lock))
-#define read_trylock(lock)	__cond_lock(_read_trylock(lock))
-#define write_trylock(lock)	__cond_lock(_write_trylock(lock))
+#define spin_trylock(lock)		__cond_lock(_spin_trylock(lock))
+#define read_trylock(lock)		__cond_lock(_read_trylock(lock))
+#define write_trylock(lock)		__cond_lock(_write_trylock(lock))
 
-#define spin_lock(lock)		_spin_lock(lock)
-#define write_lock(lock)	_write_lock(lock)
-#define read_lock(lock)		_read_lock(lock)
+#define spin_lock(lock)			_spin_lock(lock)
+#define write_lock(lock)		_write_lock(lock)
+#define read_lock(lock)			_read_lock(lock)
 
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
 #define spin_lock_irqsave(lock, flags)	flags = _spin_lock_irqsave(lock)
 #define read_lock_irqsave(lock, flags)	flags = _read_lock_irqsave(lock)
 #define write_lock_irqsave(lock, flags)	flags = _write_lock_irqsave(lock)
@@ -470,137 +171,59 @@ do { \
 #define write_lock_irq(lock)		_write_lock_irq(lock)
 #define write_lock_bh(lock)		_write_lock_bh(lock)
 
-#define spin_unlock(lock)	_spin_unlock(lock)
-#define write_unlock(lock)	_write_unlock(lock)
-#define read_unlock(lock)	_read_unlock(lock)
+#define spin_unlock(lock)		_spin_unlock(lock)
+#define write_unlock(lock)		_write_unlock(lock)
+#define read_unlock(lock)		_read_unlock(lock)
 
-#define spin_unlock_irqrestore(lock, flags)	_spin_unlock_irqrestore(lock, flags)
+#define spin_unlock_irqrestore(lock, flags) \
+					_spin_unlock_irqrestore(lock, flags)
 #define spin_unlock_irq(lock)		_spin_unlock_irq(lock)
 #define spin_unlock_bh(lock)		_spin_unlock_bh(lock)
 
-#define read_unlock_irqrestore(lock, flags)	_read_unlock_irqrestore(lock, flags)
-#define read_unlock_irq(lock)			_read_unlock_irq(lock)
-#define read_unlock_bh(lock)			_read_unlock_bh(lock)
+#define read_unlock_irqrestore(lock, flags) \
+					_read_unlock_irqrestore(lock, flags)
+#define read_unlock_irq(lock)		_read_unlock_irq(lock)
+#define read_unlock_bh(lock)		_read_unlock_bh(lock)
 
-#define write_unlock_irqrestore(lock, flags)	_write_unlock_irqrestore(lock, flags)
-#define write_unlock_irq(lock)			_write_unlock_irq(lock)
-#define write_unlock_bh(lock)			_write_unlock_bh(lock)
+#define write_unlock_irqrestore(lock, flags) \
+					_write_unlock_irqrestore(lock, flags)
+#define write_unlock_irq(lock)		_write_unlock_irq(lock)
+#define write_unlock_bh(lock)		_write_unlock_bh(lock)
 
-#define spin_trylock_bh(lock)			__cond_lock(_spin_trylock_bh(lock))
+#define spin_trylock_bh(lock)		__cond_lock(_spin_trylock_bh(lock))
 
 #define spin_trylock_irq(lock) \
 ({ \
 	local_irq_disable(); \
 	_spin_trylock(lock) ? \
-	1 : ({local_irq_enable(); 0; }); \
+	1 : ({ local_irq_enable(); 0;  }); \
 })
 
 #define spin_trylock_irqsave(lock, flags) \
 ({ \
 	local_irq_save(flags); \
 	_spin_trylock(lock) ? \
-	1 : ({local_irq_restore(flags); 0;}); \
+	1 : ({ local_irq_restore(flags); 0; }); \
 })
 
-#ifdef CONFIG_LOCKMETER
-extern void _metered_spin_lock   (spinlock_t *lock);
-extern void _metered_spin_unlock (spinlock_t *lock);
-extern int  _metered_spin_trylock(spinlock_t *lock);
-extern void _metered_read_lock    (rwlock_t *lock);
-extern void _metered_read_unlock  (rwlock_t *lock);
-extern void _metered_write_lock   (rwlock_t *lock);
-extern void _metered_write_unlock (rwlock_t *lock);
-extern int  _metered_read_trylock (rwlock_t *lock);
-extern int  _metered_write_trylock(rwlock_t *lock);
-#endif
-
-/* "lock on reference count zero" */
-#ifndef ATOMIC_DEC_AND_LOCK
-#include <asm/atomic.h>
-extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
-#endif
-
-#define atomic_dec_and_lock(atomic,lock) __cond_lock(_atomic_dec_and_lock(atomic,lock))
-
-/*
- *  bit-based spin_lock()
- *
- * Don't use this unless you really need to: spin_lock() and spin_unlock()
- * are significantly faster.
- */
-static inline void bit_spin_lock(int bitnum, unsigned long *addr)
-{
-	/*
-	 * Assuming the lock is uncontended, this never enters
-	 * the body of the outer loop. If it is contended, then
-	 * within the inner loop a non-atomic test is used to
-	 * busywait with less bus contention for a good time to
-	 * attempt to acquire the lock bit.
-	 */
-	preempt_disable();
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
-	while (test_and_set_bit(bitnum, addr)) {
-		while (test_bit(bitnum, addr)) {
-			preempt_enable();
-			cpu_relax();
-			preempt_disable();
-		}
-	}
-#endif
-	__acquire(bitlock);
-}
-
 /*
- * Return true if it was acquired
+ * Pull the atomic_t declaration:
+ * (asm-mips/atomic.h needs above definitions)
  */
-static inline int bit_spin_trylock(int bitnum, unsigned long *addr)
-{
-	preempt_disable();	
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
-	if (test_and_set_bit(bitnum, addr)) {
-		preempt_enable();
-		return 0;
-	}
-#endif
-	__acquire(bitlock);
-	return 1;
-}
-
-/*
- *  bit-based spin_unlock()
- */
-static inline void bit_spin_unlock(int bitnum, unsigned long *addr)
-{
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
-	BUG_ON(!test_bit(bitnum, addr));
-	smp_mb__before_clear_bit();
-	clear_bit(bitnum, addr);
-#endif
-	preempt_enable();
-	__release(bitlock);
-}
-
-/*
- * Return true if the lock is held.
+#include <asm/atomic.h>
+/**
+ * atomic_dec_and_lock - lock on reaching reference count zero
+ * @atomic: the atomic counter
+ * @lock: the spinlock in question
  */
-static inline int bit_spin_is_locked(int bitnum, unsigned long *addr)
-{
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
-	return test_bit(bitnum, addr);
-#elif defined CONFIG_PREEMPT
-	return preempt_count();
-#else
-	return 1;
-#endif
-}
-
-#define DEFINE_SPINLOCK(x) spinlock_t x = SPIN_LOCK_UNLOCKED
-#define DEFINE_RWLOCK(x) rwlock_t x = RW_LOCK_UNLOCKED
+extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
+#define atomic_dec_and_lock(atomic, lock) \
+		__cond_lock(_atomic_dec_and_lock(atomic, lock))
 
 /**
  * spin_can_lock - would spin_trylock() succeed?
  * @lock: the spinlock in question.
  */
-#define spin_can_lock(lock)		(!spin_is_locked(lock))
+#define spin_can_lock(lock)	(!spin_is_locked(lock))
 
 #endif /* __LINUX_SPINLOCK_H */