asm-generic: add generic versions of common headers

These are all kernel internal interfaces that get copied
around a lot. In most cases, architectures can provide
their own optimized versions, but these generic versions
can work as well.

I have tried to use the most common contents of each
header to allow existing architectures to migrate easily.

Thanks to Remis for suggesting a number of cleanups.

Signed-off-by: Remis Lima Baima <remis.developer@googlemail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/include/asm-generic/irqflags.h b/include/asm-generic/irqflags.h
new file mode 100644
index 0000000..9aebf61
--- /dev/null
+++ b/include/asm-generic/irqflags.h
@@ -0,0 +1,72 @@
+#ifndef __ASM_GENERIC_IRQFLAGS_H
+#define __ASM_GENERIC_IRQFLAGS_H
+
+/*
+ * All architectures should implement at least the first two functions,
+ * usually inline assembly will be the best way.
+ */
+#ifndef RAW_IRQ_DISABLED
+#define RAW_IRQ_DISABLED 0
+#define RAW_IRQ_ENABLED 1
+#endif
+
+/* read interrupt enabled status */
+#ifndef __raw_local_save_flags
+unsigned long __raw_local_save_flags(void);
+#endif
+
+/* set interrupt enabled status */
+#ifndef raw_local_irq_restore
+void raw_local_irq_restore(unsigned long flags);
+#endif
+
+/* get status and disable interrupts */
+#ifndef __raw_local_irq_save
+static inline unsigned long __raw_local_irq_save(void)
+{
+	unsigned long flags;
+	flags = __raw_local_save_flags();
+	raw_local_irq_restore(RAW_IRQ_DISABLED);
+	return flags;
+}
+#endif
+
+/* test flags */
+#ifndef raw_irqs_disabled_flags
+static inline int raw_irqs_disabled_flags(unsigned long flags)
+{
+	return flags == RAW_IRQ_DISABLED;
+}
+#endif
+
+/* unconditionally enable interrupts */
+#ifndef raw_local_irq_enable
+static inline void raw_local_irq_enable(void)
+{
+	raw_local_irq_restore(RAW_IRQ_ENABLED);
+}
+#endif
+
+/* unconditionally disable interrupts */
+#ifndef raw_local_irq_disable
+static inline void raw_local_irq_disable(void)
+{
+	raw_local_irq_restore(RAW_IRQ_DISABLED);
+}
+#endif
+
+/* test hardware interrupt enable bit */
+#ifndef raw_irqs_disabled
+static inline int raw_irqs_disabled(void)
+{
+	return raw_irqs_disabled_flags(__raw_local_save_flags());
+}
+#endif
+
+#define raw_local_save_flags(flags) \
+	do { (flags) = __raw_local_save_flags(); } while (0)
+
+#define raw_local_irq_save(flags) \
+	do { (flags) = __raw_local_irq_save(); } while (0)
+
+#endif /* __ASM_GENERIC_IRQFLAGS_H */