locking: Allow arch-inlined spinlocks

This allows an architecture to specify per lock variant if the
locking code should be kept out-of-line or inlined.

If an architecure wants out-of-line locking code no change is
needed. To force inlining of e.g. spin_lock() the line:

  #define __always_inline__spin_lock

needs to be added to arch/<...>/include/asm/spinlock.h

If CONFIG_DEBUG_SPINLOCK or CONFIG_GENERIC_LOCKBREAK are
defined the per architecture defines are (partly) ignored and
still out-of-line spinlock code will be generated.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Horst Hartmann <horsth@linux.vnet.ibm.com>
Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: <linux-arch@vger.kernel.org>
LKML-Reference: <20090831124418.375299024@de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 119 insertions, 0 deletions

diff --git a/include/linux/spinlock_api_smp.h b/include/linux/spinlock_api_smp.h
index 6b108f5fb149..1a411e3fab95 100644
--- a/include/linux/spinlock_api_smp.h
+++ b/include/linux/spinlock_api_smp.h
@@ -60,6 +60,125 @@ void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
 void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
 							__releases(lock);
 
+#ifndef CONFIG_DEBUG_SPINLOCK
+#ifndef CONFIG_GENERIC_LOCKBREAK
+
+#ifdef __always_inline__spin_lock
+#define _spin_lock(lock) __spin_lock(lock)
+#endif
+
+#ifdef __always_inline__read_lock
+#define _read_lock(lock) __read_lock(lock)
+#endif
+
+#ifdef __always_inline__write_lock
+#define _write_lock(lock) __write_lock(lock)
+#endif
+
+#ifdef __always_inline__spin_lock_bh
+#define _spin_lock_bh(lock) __spin_lock_bh(lock)
+#endif
+
+#ifdef __always_inline__read_lock_bh
+#define _read_lock_bh(lock) __read_lock_bh(lock)
+#endif
+
+#ifdef __always_inline__write_lock_bh
+#define _write_lock_bh(lock) __write_lock_bh(lock)
+#endif
+
+#ifdef __always_inline__spin_lock_irq
+#define _spin_lock_irq(lock) __spin_lock_irq(lock)
+#endif
+
+#ifdef __always_inline__read_lock_irq
+#define _read_lock_irq(lock) __read_lock_irq(lock)
+#endif
+
+#ifdef __always_inline__write_lock_irq
+#define _write_lock_irq(lock) __write_lock_irq(lock)
+#endif
+
+#ifdef __always_inline__spin_lock_irqsave
+#define _spin_lock_irqsave(lock) __spin_lock_irqsave(lock)
+#endif
+
+#ifdef __always_inline__read_lock_irqsave
+#define _read_lock_irqsave(lock) __read_lock_irqsave(lock)
+#endif
+
+#ifdef __always_inline__write_lock_irqsave
+#define _write_lock_irqsave(lock) __write_lock_irqsave(lock)
+#endif
+
+#endif /* !CONFIG_GENERIC_LOCKBREAK */
+
+#ifdef __always_inline__spin_trylock
+#define _spin_trylock(lock) __spin_trylock(lock)
+#endif
+
+#ifdef __always_inline__read_trylock
+#define _read_trylock(lock) __read_trylock(lock)
+#endif
+
+#ifdef __always_inline__write_trylock
+#define _write_trylock(lock) __write_trylock(lock)
+#endif
+
+#ifdef __always_inline__spin_trylock_bh
+#define _spin_trylock_bh(lock) __spin_trylock_bh(lock)
+#endif
+
+#ifdef __always_inline__spin_unlock
+#define _spin_unlock(lock) __spin_unlock(lock)
+#endif
+
+#ifdef __always_inline__read_unlock
+#define _read_unlock(lock) __read_unlock(lock)
+#endif
+
+#ifdef __always_inline__write_unlock
+#define _write_unlock(lock) __write_unlock(lock)
+#endif
+
+#ifdef __always_inline__spin_unlock_bh
+#define _spin_unlock_bh(lock) __spin_unlock_bh(lock)
+#endif
+
+#ifdef __always_inline__read_unlock_bh
+#define _read_unlock_bh(lock) __read_unlock_bh(lock)
+#endif
+
+#ifdef __always_inline__write_unlock_bh
+#define _write_unlock_bh(lock) __write_unlock_bh(lock)
+#endif
+
+#ifdef __always_inline__spin_unlock_irq
+#define _spin_unlock_irq(lock) __spin_unlock_irq(lock)
+#endif
+
+#ifdef __always_inline__read_unlock_irq
+#define _read_unlock_irq(lock) __read_unlock_irq(lock)
+#endif
+
+#ifdef __always_inline__write_unlock_irq
+#define _write_unlock_irq(lock) __write_unlock_irq(lock)
+#endif
+
+#ifdef __always_inline__spin_unlock_irqrestore
+#define _spin_unlock_irqrestore(lock, flags) __spin_unlock_irqrestore(lock, flags)
+#endif
+
+#ifdef __always_inline__read_unlock_irqrestore
+#define _read_unlock_irqrestore(lock, flags) __read_unlock_irqrestore(lock, flags)
+#endif
+
+#ifdef __always_inline__write_unlock_irqrestore
+#define _write_unlock_irqrestore(lock, flags) __write_unlock_irqrestore(lock, flags)
+#endif
+
+#endif /* CONFIG_DEBUG_SPINLOCK */
+
 static inline int __spin_trylock(spinlock_t *lock)
 {
 	preempt_disable();