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, 63 insertions, 0 deletions

diff --git a/kernel/arch/mips/loongson/loongson-3/cop2-ex.c b/kernel/arch/mips/loongson/loongson-3/cop2-ex.c
new file mode 100644
index 000000000..ea13764d0
--- /dev/null
+++ b/kernel/arch/mips/loongson/loongson-3/cop2-ex.c
@@ -0,0 +1,63 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2014 Lemote Corporation.
+ *   written by Huacai Chen <chenhc@lemote.com>
+ *
+ * based on arch/mips/cavium-octeon/cpu.c
+ * Copyright (C) 2009 Wind River Systems,
+ *   written by Ralf Baechle <ralf@linux-mips.org>
+ */
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/notifier.h>
+
+#include <asm/fpu.h>
+#include <asm/cop2.h>
+#include <asm/current.h>
+#include <asm/mipsregs.h>
+
+static int loongson_cu2_call(struct notifier_block *nfb, unsigned long action,
+	void *data)
+{
+	int fpu_owned;
+	int fr = !test_thread_flag(TIF_32BIT_FPREGS);
+
+	switch (action) {
+	case CU2_EXCEPTION:
+		preempt_disable();
+		fpu_owned = __is_fpu_owner();
+		if (!fr)
+			set_c0_status(ST0_CU1 | ST0_CU2);
+		else
+			set_c0_status(ST0_CU1 | ST0_CU2 | ST0_FR);
+		enable_fpu_hazard();
+		KSTK_STATUS(current) |= (ST0_CU1 | ST0_CU2);
+		if (fr)
+			KSTK_STATUS(current) |= ST0_FR;
+		else
+			KSTK_STATUS(current) &= ~ST0_FR;
+		/* If FPU is owned, we needn't init or restore fp */
+		if (!fpu_owned) {
+			set_thread_flag(TIF_USEDFPU);
+			if (!used_math()) {
+				_init_fpu(current->thread.fpu.fcr31);
+				set_used_math();
+			} else
+				_restore_fp(current);
+		}
+		preempt_enable();
+
+		return NOTIFY_STOP;	/* Don't call default notifier */
+	}
+
+	return NOTIFY_OK;		/* Let default notifier send signals */
+}
+
+static int __init loongson_cu2_setup(void)
+{
+	return cu2_notifier(loongson_cu2_call, 0);
+}
+early_initcall(loongson_cu2_setup);