Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 107 insertions, 0 deletions

diff --git a/kernel/arch/metag/include/asm/barrier.h b/kernel/arch/metag/include/asm/barrier.h
new file mode 100644
index 000000000..d703d8e26
--- /dev/null
+++ b/kernel/arch/metag/include/asm/barrier.h
@@ -0,0 +1,107 @@
+#ifndef _ASM_METAG_BARRIER_H
+#define _ASM_METAG_BARRIER_H
+
+#include <asm/metag_mem.h>
+
+#define nop()		asm volatile ("NOP")
+
+#ifdef CONFIG_METAG_META21
+
+/* HTP and above have a system event to fence writes */
+static inline void wr_fence(void)
+{
+	volatile int *flushptr = (volatile int *) LINSYSEVENT_WR_FENCE;
+	barrier();
+	*flushptr = 0;
+	barrier();
+}
+
+#else /* CONFIG_METAG_META21 */
+
+/*
+ * ATP doesn't have system event to fence writes, so it is necessary to flush
+ * the processor write queues as well as possibly the write combiner (depending
+ * on the page being written).
+ * To ensure the write queues are flushed we do 4 writes to a system event
+ * register (in this case write combiner flush) which will also flush the write
+ * combiner.
+ */
+static inline void wr_fence(void)
+{
+	volatile int *flushptr = (volatile int *) LINSYSEVENT_WR_COMBINE_FLUSH;
+	barrier();
+	*flushptr = 0;
+	*flushptr = 0;
+	*flushptr = 0;
+	*flushptr = 0;
+	barrier();
+}
+
+#endif /* !CONFIG_METAG_META21 */
+
+/* flush writes through the write combiner */
+#define mb()		wr_fence()
+#define rmb()		barrier()
+#define wmb()		mb()
+
+#define dma_rmb()	rmb()
+#define dma_wmb()	wmb()
+
+#ifndef CONFIG_SMP
+#define fence()		do { } while (0)
+#define smp_mb()        barrier()
+#define smp_rmb()       barrier()
+#define smp_wmb()       barrier()
+#else
+
+#ifdef CONFIG_METAG_SMP_WRITE_REORDERING
+/*
+ * Write to the atomic memory unlock system event register (command 0). This is
+ * needed before a write to shared memory in a critical section, to prevent
+ * external reordering of writes before the fence on other threads with writes
+ * after the fence on this thread (and to prevent the ensuing cache-memory
+ * incoherence). It is therefore ineffective if used after and on the same
+ * thread as a write.
+ */
+static inline void fence(void)
+{
+	volatile int *flushptr = (volatile int *) LINSYSEVENT_WR_ATOMIC_UNLOCK;
+	barrier();
+	*flushptr = 0;
+	barrier();
+}
+#define smp_mb()        fence()
+#define smp_rmb()       fence()
+#define smp_wmb()       barrier()
+#else
+#define fence()		do { } while (0)
+#define smp_mb()        barrier()
+#define smp_rmb()       barrier()
+#define smp_wmb()       barrier()
+#endif
+#endif
+
+#define read_barrier_depends()		do { } while (0)
+#define smp_read_barrier_depends()	do { } while (0)
+
+#define set_mb(var, value) do { var = value; smp_mb(); } while (0)
+
+#define smp_store_release(p, v)						\
+do {									\
+	compiletime_assert_atomic_type(*p);				\
+	smp_mb();							\
+	ACCESS_ONCE(*p) = (v);						\
+} while (0)
+
+#define smp_load_acquire(p)						\
+({									\
+	typeof(*p) ___p1 = ACCESS_ONCE(*p);				\
+	compiletime_assert_atomic_type(*p);				\
+	smp_mb();							\
+	___p1;								\
+})
+
+#define smp_mb__before_atomic()	barrier()
+#define smp_mb__after_atomic()	barrier()
+
+#endif /* _ASM_METAG_BARRIER_H */