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, 227 insertions, 0 deletions

diff --git a/kernel/drivers/clocksource/pxa_timer.c b/kernel/drivers/clocksource/pxa_timer.c
new file mode 100644
index 000000000..d9438af2b
--- /dev/null
+++ b/kernel/drivers/clocksource/pxa_timer.c
@@ -0,0 +1,227 @@
+/*
+ * arch/arm/mach-pxa/time.c
+ *
+ * PXA clocksource, clockevents, and OST interrupt handlers.
+ * Copyright (c) 2007 by Bill Gatliff <bgat@billgatliff.com>.
+ *
+ * Derived from Nicolas Pitre's PXA timer handler Copyright (c) 2001
+ * by MontaVista Software, Inc.  (Nico, your code rocks!)
+ *
+ * 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/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/sched_clock.h>
+
+#include <asm/div64.h>
+
+#define OSMR0		0x00	/* OS Timer 0 Match Register */
+#define OSMR1		0x04	/* OS Timer 1 Match Register */
+#define OSMR2		0x08	/* OS Timer 2 Match Register */
+#define OSMR3		0x0C	/* OS Timer 3 Match Register */
+
+#define OSCR		0x10	/* OS Timer Counter Register */
+#define OSSR		0x14	/* OS Timer Status Register */
+#define OWER		0x18	/* OS Timer Watchdog Enable Register */
+#define OIER		0x1C	/* OS Timer Interrupt Enable Register */
+
+#define OSSR_M3		(1 << 3)	/* Match status channel 3 */
+#define OSSR_M2		(1 << 2)	/* Match status channel 2 */
+#define OSSR_M1		(1 << 1)	/* Match status channel 1 */
+#define OSSR_M0		(1 << 0)	/* Match status channel 0 */
+
+#define OIER_E0		(1 << 0)	/* Interrupt enable channel 0 */
+
+/*
+ * This is PXA's sched_clock implementation. This has a resolution
+ * of at least 308 ns and a maximum value of 208 days.
+ *
+ * The return value is guaranteed to be monotonic in that range as
+ * long as there is always less than 582 seconds between successive
+ * calls to sched_clock() which should always be the case in practice.
+ */
+
+#define timer_readl(reg) readl_relaxed(timer_base + (reg))
+#define timer_writel(val, reg) writel_relaxed((val), timer_base + (reg))
+
+static void __iomem *timer_base;
+
+static u64 notrace pxa_read_sched_clock(void)
+{
+	return timer_readl(OSCR);
+}
+
+
+#define MIN_OSCR_DELTA 16
+
+static irqreturn_t
+pxa_ost0_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *c = dev_id;
+
+	/* Disarm the compare/match, signal the event. */
+	timer_writel(timer_readl(OIER) & ~OIER_E0, OIER);
+	timer_writel(OSSR_M0, OSSR);
+	c->event_handler(c);
+
+	return IRQ_HANDLED;
+}
+
+static int
+pxa_osmr0_set_next_event(unsigned long delta, struct clock_event_device *dev)
+{
+	unsigned long next, oscr;
+
+	timer_writel(timer_readl(OIER) | OIER_E0, OIER);
+	next = timer_readl(OSCR) + delta;
+	timer_writel(next, OSMR0);
+	oscr = timer_readl(OSCR);
+
+	return (signed)(next - oscr) <= MIN_OSCR_DELTA ? -ETIME : 0;
+}
+
+static void
+pxa_osmr0_set_mode(enum clock_event_mode mode, struct clock_event_device *dev)
+{
+	switch (mode) {
+	case CLOCK_EVT_MODE_ONESHOT:
+		timer_writel(timer_readl(OIER) & ~OIER_E0, OIER);
+		timer_writel(OSSR_M0, OSSR);
+		break;
+
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_SHUTDOWN:
+		/* initializing, released, or preparing for suspend */
+		timer_writel(timer_readl(OIER) & ~OIER_E0, OIER);
+		timer_writel(OSSR_M0, OSSR);
+		break;
+
+	case CLOCK_EVT_MODE_RESUME:
+	case CLOCK_EVT_MODE_PERIODIC:
+		break;
+	}
+}
+
+#ifdef CONFIG_PM
+static unsigned long osmr[4], oier, oscr;
+
+static void pxa_timer_suspend(struct clock_event_device *cedev)
+{
+	osmr[0] = timer_readl(OSMR0);
+	osmr[1] = timer_readl(OSMR1);
+	osmr[2] = timer_readl(OSMR2);
+	osmr[3] = timer_readl(OSMR3);
+	oier = timer_readl(OIER);
+	oscr = timer_readl(OSCR);
+}
+
+static void pxa_timer_resume(struct clock_event_device *cedev)
+{
+	/*
+	 * Ensure that we have at least MIN_OSCR_DELTA between match
+	 * register 0 and the OSCR, to guarantee that we will receive
+	 * the one-shot timer interrupt.  We adjust OSMR0 in preference
+	 * to OSCR to guarantee that OSCR is monotonically incrementing.
+	 */
+	if (osmr[0] - oscr < MIN_OSCR_DELTA)
+		osmr[0] += MIN_OSCR_DELTA;
+
+	timer_writel(osmr[0], OSMR0);
+	timer_writel(osmr[1], OSMR1);
+	timer_writel(osmr[2], OSMR2);
+	timer_writel(osmr[3], OSMR3);
+	timer_writel(oier, OIER);
+	timer_writel(oscr, OSCR);
+}
+#else
+#define pxa_timer_suspend NULL
+#define pxa_timer_resume NULL
+#endif
+
+static struct clock_event_device ckevt_pxa_osmr0 = {
+	.name		= "osmr0",
+	.features	= CLOCK_EVT_FEAT_ONESHOT,
+	.rating		= 200,
+	.set_next_event	= pxa_osmr0_set_next_event,
+	.set_mode	= pxa_osmr0_set_mode,
+	.suspend	= pxa_timer_suspend,
+	.resume		= pxa_timer_resume,
+};
+
+static struct irqaction pxa_ost0_irq = {
+	.name		= "ost0",
+	.flags		= IRQF_TIMER | IRQF_IRQPOLL,
+	.handler	= pxa_ost0_interrupt,
+	.dev_id		= &ckevt_pxa_osmr0,
+};
+
+static void __init pxa_timer_common_init(int irq, unsigned long clock_tick_rate)
+{
+	timer_writel(0, OIER);
+	timer_writel(OSSR_M0 | OSSR_M1 | OSSR_M2 | OSSR_M3, OSSR);
+
+	sched_clock_register(pxa_read_sched_clock, 32, clock_tick_rate);
+
+	ckevt_pxa_osmr0.cpumask = cpumask_of(0);
+
+	setup_irq(irq, &pxa_ost0_irq);
+
+	clocksource_mmio_init(timer_base + OSCR, "oscr0", clock_tick_rate, 200,
+			      32, clocksource_mmio_readl_up);
+	clockevents_config_and_register(&ckevt_pxa_osmr0, clock_tick_rate,
+					MIN_OSCR_DELTA * 2, 0x7fffffff);
+}
+
+static void __init pxa_timer_dt_init(struct device_node *np)
+{
+	struct clk *clk;
+	int irq;
+
+	/* timer registers are shared with watchdog timer */
+	timer_base = of_iomap(np, 0);
+	if (!timer_base)
+		panic("%s: unable to map resource\n", np->name);
+
+	clk = of_clk_get(np, 0);
+	if (IS_ERR(clk)) {
+		pr_crit("%s: unable to get clk\n", np->name);
+		return;
+	}
+	clk_prepare_enable(clk);
+
+	/* we are only interested in OS-timer0 irq */
+	irq = irq_of_parse_and_map(np, 0);
+	if (irq <= 0) {
+		pr_crit("%s: unable to parse OS-timer0 irq\n", np->name);
+		return;
+	}
+
+	pxa_timer_common_init(irq, clk_get_rate(clk));
+}
+CLOCKSOURCE_OF_DECLARE(pxa_timer, "marvell,pxa-timer", pxa_timer_dt_init);
+
+/*
+ * Legacy timer init for non device-tree boards.
+ */
+void __init pxa_timer_nodt_init(int irq, void __iomem *base,
+	unsigned long clock_tick_rate)
+{
+	struct clk *clk;
+
+	timer_base = base;
+	clk = clk_get(NULL, "OSTIMER0");
+	if (clk && !IS_ERR(clk))
+		clk_prepare_enable(clk);
+	else
+		pr_crit("%s: unable to get clk\n", __func__);
+
+	pxa_timer_common_init(irq, clock_tick_rate);
+}