Initial commit from HTC m7ul-3.4.10-jb-crc-ddcfb8c
diff --git a/arch/arm/include/asm/mutex.h b/arch/arm/include/asm/mutex.h
new file mode 100644
index 0000000..835da92
--- /dev/null
+++ b/arch/arm/include/asm/mutex.h
@@ -0,0 +1,101 @@
+#ifndef _ASM_MUTEX_H
+#define _ASM_MUTEX_H
+
+#if __LINUX_ARM_ARCH__ < 6
+# include <asm-generic/mutex-xchg.h>
+#else
+
+static inline void
+__mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *))
+{
+ int __ex_flag, __res;
+
+ __asm__ (
+
+ "ldrex %0, [%2] \n\t"
+ "sub %0, %0, #1 \n\t"
+ "strex %1, %0, [%2] "
+
+ : "=&r" (__res), "=&r" (__ex_flag)
+ : "r" (&(count)->counter)
+ : "cc","memory" );
+
+ __res |= __ex_flag;
+ if (unlikely(__res != 0))
+ fail_fn(count);
+ else
+ smp_rmb();
+}
+
+static inline int
+__mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *))
+{
+ int __ex_flag, __res;
+
+ __asm__ (
+
+ "ldrex %0, [%2] \n\t"
+ "sub %0, %0, #1 \n\t"
+ "strex %1, %0, [%2] "
+
+ : "=&r" (__res), "=&r" (__ex_flag)
+ : "r" (&(count)->counter)
+ : "cc","memory" );
+
+ __res |= __ex_flag;
+ if (unlikely(__res != 0))
+ __res = fail_fn(count);
+ else
+ smp_rmb();
+
+ return __res;
+}
+
+static inline void
+__mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *))
+{
+ int __ex_flag, __res, __orig;
+
+ smp_wmb();
+ __asm__ (
+
+ "ldrex %0, [%3] \n\t"
+ "add %1, %0, #1 \n\t"
+ "strex %2, %1, [%3] "
+
+ : "=&r" (__orig), "=&r" (__res), "=&r" (__ex_flag)
+ : "r" (&(count)->counter)
+ : "cc","memory" );
+
+ __orig |= __ex_flag;
+ if (unlikely(__orig != 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 *))
+{
+ int __ex_flag, __res, __orig;
+
+ __asm__ (
+
+ "1: ldrex %0, [%3] \n\t"
+ "subs %1, %0, #1 \n\t"
+ "strexeq %2, %1, [%3] \n\t"
+ "movlt %0, #0 \n\t"
+ "cmpeq %2, #0 \n\t"
+ "bgt 1b "
+
+ : "=&r" (__orig), "=&r" (__res), "=&r" (__ex_flag)
+ : "r" (&count->counter)
+ : "cc", "memory" );
+ if (__orig)
+ smp_rmb();
+
+ return __orig;
+}
+
+#endif
+#endif