Please help me reviewing the code, because inline assembly bug is
always tricky and miserable.
Jun
diff -Nru linux/include/asm-mips/spinlock.h.orig linux/include/asm-mips/spinlock.h
--- linux/include/asm-mips/spinlock.h.orig 2004-01-05 10:48:38.000000000 -0800
+++ linux/include/asm-mips/spinlock.h 2004-03-15 18:50:30.000000000 -0800
@@ -167,4 +167,28 @@
: "memory");
}
+static inline int _raw_write_trylock(rwlock_t *rw)
+{
+ unsigned int tmp;
+ int ret;
+
+ __asm__ __volatile__(
+ ".set\tnoreorder\t\t\t# _raw_write_trylock\n"
+ "li\t%2, 0\n\t"
+ "1:\tll\t%1, %3\n\t"
+ "bnez\t%1, 2f\n\t"
+ "lui\t%1, 0x8000\n\t"
+ "sc\t%1, %0\n\t"
+ "beqz\t%1, 1b\n\t"
+ "sync\n\t"
+ "li\t%2, 1\n\t"
+ ".set\treorder\n"
+ "2:"
+ : "=m" (rw->lock), "=&r" (tmp), "=&r" (ret)
+ : "m" (rw->lock)
+ : "memory");
+
+ return ret;
+}
+
#endif /* _ASM_SPINLOCK_H */
