Initial commit

include/l4/lib/spinlock.h

@@ -0,0 +1,57 @@
+#ifndef __LIB_SPINLOCK_H__
+#define __LIB_SPINLOCK_H__
+
+#include <l4/lib/string.h>
+#include <l4/generic/preempt.h>
+#include INC_ARCH(exception.h)
+
+struct spinlock {
+	unsigned int lock;
+};
+
+static inline void spin_lock_init(struct spinlock *s)
+{
+	memset(s, 0, sizeof(struct spinlock));
+}
+
+/*
+ * - Guards from deadlock against local processes, but not local irqs.
+ * - To be used for synchronising against processes on *other* cpus.
+ */
+static inline void spin_lock(struct spinlock *s)
+{
+	preempt_disable();
+#if defined(CONFIG_SMP)
+	__spin_lock(&s->lock);
+#endif
+}
+
+static inline void spin_unlock(struct spinlock *s)
+{
+#if defined(CONFIG_SMP)
+	__spin_unlock(&s->lock);
+#endif
+	preempt_enable();
+}
+
+/*
+ * - Guards from deadlock against local processes *and* local irqs.
+ * - To be used for synchronising against processes and irqs
+ *   on other cpus.
+ */
+static inline void spin_lock_irq(struct spinlock *s)
+{
+	irq_local_disable();	/* Even in UP an irq could deadlock us */
+#if defined(CONFIG_SMP)
+	__spin_lock(&s->lock);
+#endif
+}
+
+static inline void spin_unlock_irq(struct spinlock *s)
+{
+#if defined(CONFIG_SMP)
+	__spin_unlock(&s->lock);
+#endif
+	irq_local_enable();
+}
+#endif /* __LIB__SPINLOCK_H__ */