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authorLinus Torvalds <torvalds@linux-foundation.org>2009-01-07 23:00:25 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-07 23:00:25 +0300
commit5bb47b9ff3d16d40f8d45380b373497a545fa280 (patch)
treee13dd34395473342dc75eff5cbaf5b1ea753631c /arch/blackfin/include/asm/mutex.h
parent2f2408a88cf8fa43febfd7fb5783e61b2937b0f9 (diff)
parent06af15e086e39a5a2a2413973a64af8e10122f28 (diff)
downloadlinux-5bb47b9ff3d16d40f8d45380b373497a545fa280.tar.xz
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/blackfin-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/blackfin-2.6: (171 commits) Blackfin arch: fix bug - BF527 0.2 silicon has different CPUID (DSPID) value Blackfin arch: Enlarge flash partition for kenel for bf533/bf537 boards Blackfin arch: fix bug: kernel crash when enable SDIO host driver Blackfin arch: Print FP at level KERN_NOTICE Blackfin arch: drop ad73311 test code Blackfin arch: update board default configs Blackfin arch: Set PB4 as the default irq for bf548 board v1.4+. Blackfin arch: fix typo in early printk bit size processing Blackfin arch: enable reprogram cclk and sclk for bf518f-ezbrd Blackfin arch: add SDIO host driver platform data Blackfin arch: fix bug - kernel stops at initial console Blackfin arch: fix bug - kernel crash after config IP for ethernet port Blackfin arch: add sdh support for bf518f-ezbrd Blackfin arch: fix bug - kernel detects BF532 incorrectly Blackfin arch: add () to avoid warnings from gcc Blackfin arch: change HWTRACE Kconfig and set it on default Blackfin arch: Clean oprofile build path for blackfin Blackfin arch: remove hardware PM code, oprofile not use it Blackfin arch: rewrite get_sclk()/get_vco() Blackfin arch: cleanup and unify the ins functions ...
Diffstat (limited to 'arch/blackfin/include/asm/mutex.h')
-rw-r--r--arch/blackfin/include/asm/mutex.h63
1 files changed, 63 insertions, 0 deletions
diff --git a/arch/blackfin/include/asm/mutex.h b/arch/blackfin/include/asm/mutex.h
index 458c1f7fbc18..5d399256bf06 100644
--- a/arch/blackfin/include/asm/mutex.h
+++ b/arch/blackfin/include/asm/mutex.h
@@ -6,4 +6,67 @@
* implementation. (see asm-generic/mutex-xchg.h for details)
*/
+#ifndef _ASM_MUTEX_H
+#define _ASM_MUTEX_H
+
+#ifndef CONFIG_SMP
#include <asm-generic/mutex-dec.h>
+#else
+
+static inline void
+__mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *))
+{
+ if (unlikely(atomic_dec_return(count) < 0))
+ fail_fn(count);
+ else
+ smp_mb();
+}
+
+static inline int
+__mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *))
+{
+ if (unlikely(atomic_dec_return(count) < 0))
+ return fail_fn(count);
+ else {
+ smp_mb();
+ return 0;
+ }
+}
+
+static inline void
+__mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *))
+{
+ smp_mb();
+ if (unlikely(atomic_inc_return(count) <= 0))
+ fail_fn(count);
+}
+
+#define __mutex_slowpath_needs_to_unlock() 1
+
+static inline int
+__mutex_fastpath_trylock(atomic_t *count, int (*fail_fn)(atomic_t *))
+{
+ /*
+ * We have two variants here. The cmpxchg based one is the best one
+ * because it never induce a false contention state. It is included
+ * here because architectures using the inc/dec algorithms over the
+ * xchg ones are much more likely to support cmpxchg natively.
+ *
+ * If not we fall back to the spinlock based variant - that is
+ * just as efficient (and simpler) as a 'destructive' probing of
+ * the mutex state would be.
+ */
+#ifdef __HAVE_ARCH_CMPXCHG
+ if (likely(atomic_cmpxchg(count, 1, 0) == 1)) {
+ smp_mb();
+ return 1;
+ }
+ return 0;
+#else
+ return fail_fn(count);
+#endif
+}
+
+#endif
+
+#endif