patch-2.1.80 linux/include/asm-arm/spinlock.h

• Lines: 60
• Date: Tue Jan 20 16:39:43 1998
• Orig file: v2.1.79/linux/include/asm-arm/spinlock.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.79/linux/include/asm-arm/spinlock.h linux/include/asm-arm/spinlock.h
@@ -0,0 +1,59 @@
+#ifndef __ASM_SPINLOCK_H
+#define __ASM_SPINLOCK_H
+
+#ifndef __SMP__
+
+/*
+ * Your basic spinlocks, allowing only a single CPU anywhere
+ */
+typedef struct { } spinlock_t;
+#define SPIN_LOCK_UNLOCKED { }
+
+#define spin_lock_init(lock)	do { } while(0)
+#define spin_lock(lock)		do { } while(0)
+#define spin_trylock(lock)	do { } while(0)
+#define spin_unlock_wait(lock)	do { } while(0)
+#define spin_unlock(lock)	do { } while(0)
+#define spin_lock_irq(lock)	cli()
+#define spin_unlock_irq(lock)	sti()
+
+#define spin_lock_irqsave(lock, flags) \
+	do { save_flags(flags); cli(); } while (0)
+#define spin_unlock_irqrestore(lock, flags) \
+	restore_flags(flags)
+
+/*
+ * Read-write spinlocks, allowing multiple readers
+ * but only one writer.
+ *
+ * NOTE! it is quite common to have readers in interrupts
+ * but no interrupt writers. For those circumstances we
+ * can "mix" irq-safe locks - any writer needs to get a
+ * irq-safe write-lock, but readers can get non-irqsafe
+ * read-locks.
+ */
+typedef struct { } rwlock_t;
+#define RW_LOCK_UNLOCKED { }
+
+#define read_lock(lock)		do { } while(0)
+#define read_unlock(lock)	do { } while(0)
+#define write_lock(lock)	do { } while(0)
+#define write_unlock(lock)	do { } while(0)
+#define read_lock_irq(lock)	cli()
+#define read_unlock_irq(lock)	sti()
+#define write_lock_irq(lock)	cli()
+#define write_unlock_irq(lock)	sti()
+
+#define read_lock_irqsave(lock, flags)	\
+	do { save_flags(flags); cli(); } while (0)
+#define read_unlock_irqrestore(lock, flags) \
+	restore_flags(flags)
+#define write_lock_irqsave(lock, flags)	\
+	do { save_flags(flags); cli(); } while (0)
+#define write_unlock_irqrestore(lock, flags) \
+	restore_flags(flags)
+
+#else
+#error ARM architecture does not support spin locks
+#endif /* SMP */
+#endif /* __ASM_SPINLOCK_H */