1 files changed, 143 insertions, 0 deletions

diff --git a/include/asm-m68k/semaphore-helper.h b/include/asm-m68k/semaphore-helper.h
new file mode 100644
index 000000000000..1516a642f9a5
--- /dev/null
+++ b/include/asm-m68k/semaphore-helper.h
@@ -0,0 +1,143 @@
+#ifndef _M68K_SEMAPHORE_HELPER_H
+#define _M68K_SEMAPHORE_HELPER_H
+
+/*
+ * SMP- and interrupt-safe semaphores helper functions.
+ *
+ * (C) Copyright 1996 Linus Torvalds
+ *
+ * m68k version by Andreas Schwab
+ */
+
+#include <linux/config.h>
+#include <linux/errno.h>
+
+/*
+ * These two _must_ execute atomically wrt each other.
+ */
+static inline void wake_one_more(struct semaphore * sem)
+{
+        atomic_inc(&sem->waking);
+}
+
+#ifndef CONFIG_RMW_INSNS
+extern spinlock_t semaphore_wake_lock;
+#endif
+
+static inline int waking_non_zero(struct semaphore *sem)
+{
+        int ret;
+#ifndef CONFIG_RMW_INSNS
+        unsigned long flags;
+
+        spin_lock_irqsave(&semaphore_wake_lock, flags);
+        ret = 0;
+        if (atomic_read(&sem->waking) > 0) {
+                atomic_dec(&sem->waking);
+                ret = 1;
+        }
+        spin_unlock_irqrestore(&semaphore_wake_lock, flags);
+#else
+        int tmp1, tmp2;
+
+        __asm__ __volatile__
+          ("1:  movel   %1,%2\n"
+           "    jle     2f\n"
+           "    subql   #1,%2\n"
+           "    casl    %1,%2,%3\n"
+           "    jne     1b\n"
+           "    moveq   #1,%0\n"
+           "2:"
+           : "=d" (ret), "=d" (tmp1), "=d" (tmp2)
+           : "m" (sem->waking), "0" (0), "1" (sem->waking));
+#endif
+
+        return ret;
+}
+
+/*
+ * waking_non_zero_interruptible:
+ *      1       got the lock
+ *      0       go to sleep
+ *      -EINTR  interrupted
+ */
+static inline int waking_non_zero_interruptible(struct semaphore *sem,
+                                                struct task_struct *tsk)
+{
+        int ret;
+#ifndef CONFIG_RMW_INSNS
+        unsigned long flags;
+
+        spin_lock_irqsave(&semaphore_wake_lock, flags);
+        ret = 0;
+        if (atomic_read(&sem->waking) > 0) {
+                atomic_dec(&sem->waking);
+                ret = 1;
+        } else if (signal_pending(tsk)) {
+                atomic_inc(&sem->count);
+                ret = -EINTR;
+        }
+        spin_unlock_irqrestore(&semaphore_wake_lock, flags);
+#else
+        int tmp1, tmp2;
+
+        __asm__ __volatile__
+          ("1:  movel   %1,%2\n"
+           "    jle     2f\n"
+           "    subql   #1,%2\n"
+           "    casl    %1,%2,%3\n"
+           "    jne     1b\n"
+           "    moveq   #1,%0\n"
+           "    jra     %a4\n"
+           "2:"
+           : "=d" (ret), "=d" (tmp1), "=d" (tmp2)
+           : "m" (sem->waking), "i" (&&next), "0" (0), "1" (sem->waking));
+        if (signal_pending(tsk)) {
+                atomic_inc(&sem->count);
+                ret = -EINTR;
+        }
+next:
+#endif
+
+        return ret;
+}
+
+/*
+ * waking_non_zero_trylock:
+ *      1       failed to lock
+ *      0       got the lock
+ */
+static inline int waking_non_zero_trylock(struct semaphore *sem)
+{
+        int ret;
+#ifndef CONFIG_RMW_INSNS
+        unsigned long flags;
+
+        spin_lock_irqsave(&semaphore_wake_lock, flags);
+        ret = 1;
+        if (atomic_read(&sem->waking) > 0) {
+                atomic_dec(&sem->waking);
+                ret = 0;
+        } else
+                atomic_inc(&sem->count);
+        spin_unlock_irqrestore(&semaphore_wake_lock, flags);
+#else
+        int tmp1, tmp2;
+
+        __asm__ __volatile__
+          ("1:  movel   %1,%2\n"
+           "    jle     2f\n"
+           "    subql   #1,%2\n"
+           "    casl    %1,%2,%3\n"
+           "    jne     1b\n"
+           "    moveq   #0,%0\n"
+           "2:"
+           : "=d" (ret), "=d" (tmp1), "=d" (tmp2)
+           : "m" (sem->waking), "0" (1), "1" (sem->waking));
+        if (ret)
+                atomic_inc(&sem->count);
+#endif
+        return ret;
+}
+
+#endif