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, 71 insertions, 0 deletions

diff --git a/kernel/arch/arm/mach-imx/cpuidle-imx6q.c b/kernel/arch/arm/mach-imx/cpuidle-imx6q.c
new file mode 100644
index 000000000..8e21ccc1e
--- /dev/null
+++ b/kernel/arch/arm/mach-imx/cpuidle-imx6q.c
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2012 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/cpuidle.h>
+#include <linux/module.h>
+#include <asm/cpuidle.h>
+
+#include "common.h"
+#include "cpuidle.h"
+#include "hardware.h"
+
+static atomic_t master = ATOMIC_INIT(0);
+static DEFINE_SPINLOCK(master_lock);
+
+static int imx6q_enter_wait(struct cpuidle_device *dev,
+			    struct cpuidle_driver *drv, int index)
+{
+	if (atomic_inc_return(&master) == num_online_cpus()) {
+		/*
+		 * With this lock, we prevent other cpu to exit and enter
+		 * this function again and become the master.
+		 */
+		if (!spin_trylock(&master_lock))
+			goto idle;
+		imx6q_set_lpm(WAIT_UNCLOCKED);
+		cpu_do_idle();
+		imx6q_set_lpm(WAIT_CLOCKED);
+		spin_unlock(&master_lock);
+		goto done;
+	}
+
+idle:
+	cpu_do_idle();
+done:
+	atomic_dec(&master);
+
+	return index;
+}
+
+static struct cpuidle_driver imx6q_cpuidle_driver = {
+	.name = "imx6q_cpuidle",
+	.owner = THIS_MODULE,
+	.states = {
+		/* WFI */
+		ARM_CPUIDLE_WFI_STATE,
+		/* WAIT */
+		{
+			.exit_latency = 50,
+			.target_residency = 75,
+			.flags = CPUIDLE_FLAG_TIMER_STOP,
+			.enter = imx6q_enter_wait,
+			.name = "WAIT",
+			.desc = "Clock off",
+		},
+	},
+	.state_count = 2,
+	.safe_state_index = 0,
+};
+
+int __init imx6q_cpuidle_init(void)
+{
+	/* Set INT_MEM_CLK_LPM bit to get a reliable WAIT mode support */
+	imx6q_set_int_mem_clk_lpm(true);
+
+	return cpuidle_register(&imx6q_cpuidle_driver, NULL);
+}