Import of Linux/MIPS 2.1.36

1 files changed, 45 insertions, 7 deletions

diff --git a/include/asm-mips/semaphore.h b/include/asm-mips/semaphore.h
index f093fe519..6d527848b 100644
--- a/include/asm-mips/semaphore.h
+++ b/include/asm-mips/semaphore.h
@@ -14,23 +14,61 @@
 
 struct semaphore {
 	atomic_t count;
-	atomic_t waiting;
+	atomic_t waking;
 	struct wait_queue * wait;
 };
 
-#define MUTEX ((struct semaphore) { 1, 0, NULL })
-#define MUTEX_LOCKED ((struct semaphore) { 0, 0, NULL })
+#define MUTEX ((struct semaphore) { ATOMIC_INIT(1), ATOMIC_INIT(0), NULL })
+#define MUTEX_LOCKED ((struct semaphore) { ATOMIC_INIT(0), ATOMIC_INIT(0), NULL })
 
 extern void __down(struct semaphore * sem);
+extern int  __down_interruptible(struct semaphore * sem);
 extern void __up(struct semaphore * sem);
 
+#define sema_init(sem, val)	atomic_set(&((sem)->count), val)
+
+/*
+ * These two _must_ execute atomically wrt each other.
+ *
+ * This is trivially done with load_locked/store_cond,
+ * which we have.  Let the rest of the losers suck eggs.
+ */
+
+static inline void wake_one_more(struct semaphore * sem)
+{
+	atomic_inc(&sem->waking);
+}
+
+static inline int waking_non_zero(struct semaphore *sem)
+{
+	int ret, tmp;
+
+	__asm__ __volatile__(
+	"1:\tll\t%1,%2\n"
+	"blez\t%1,2f\n\t"
+	"subu\t%0,%1,1\n\t"
+	"sc\t%0,%2\n\t"
+	"beqz\t%0,1b\n\t"
+	"2:"
+	".text"
+	: "=r"(ret), "=r"(tmp), "=m"(__atomic_fool_gcc(&sem->waking))
+	: "0"(0));
+
+	return ret;
+}
+
 extern inline void down(struct semaphore * sem)
 {
-	while (1) {
-		if (atomic_dec_return(&sem->count) >= 0)
-			break;
+	if (atomic_dec_return(&sem->count) < 0)
 		__down(sem);
-	}
+}
+
+extern inline int down_interruptible(struct semaphore * sem)
+{
+	int ret = 0;
+	if (atomic_dec_return(&sem->count) < 0)
+		ret = __down_interruptible(sem);
+	return ret;
 }
 
 /*