Fixed few more anomalies with threaded irqs.

There is a bug that causes the sleeping irq
thread to never wake up. Investigating.

include/l4/arch/arm/exception.h

@@ -42,17 +42,20 @@ static inline void disable_irqs()
 /* Disable the irqs unconditionally, but also keep the previous state such that
  * if it was already disabled before the call, the restore call would retain
  * this state. */
-static inline void irq_local_disable_save(unsigned long *state)
+void irq_local_disable_save(unsigned long *state);
+#if 0
 {
 	unsigned long temp;
 	__asm__ __volatile__ (
 		"mrs	%0, cpsr_fc\n"
-		"orr	%1, %0, #0x80\n"
-		"msr	cpsr_fc, %1\n"
+		"orr	%2, %0, #0x80\n"
+		"msr	cpsr_fc, %2\n"
 		: "=r" (*state)
 		: "r" (*state),"r" (temp)
 	);
 }
+#endif
+
 /* Simply change it back to original state supplied in @flags. This might enable
  * or retain disabled state of the irqs for example. Useful for nested calls. */
 static inline void irq_local_restore(unsigned long state)

include/l4/arch/arm/v5/irq.h

@@ -0,0 +1,11 @@
+#ifndef __ARM_V5_IRQ_H__
+#define __ARM_V5_IRQ_H__
+
+/*
+ * Destructive atomic-read.
+ *
+ * Write 0 to byte at @location as its contents are read back.
+ */
+char l4_atomic_dest_readb(void *location);
+
+#endif