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, 147 insertions, 0 deletions

diff --git a/kernel/arch/mips/loongson1/common/irq.c b/kernel/arch/mips/loongson1/common/irq.c
new file mode 100644
index 000000000..455a7704a
--- /dev/null
+++ b/kernel/arch/mips/loongson1/common/irq.c
@@ -0,0 +1,147 @@
+/*
+ * Copyright (c) 2011 Zhang, Keguang <keguang.zhang@gmail.com>
+ *
+ * This program is free software; you can redistribute	it and/or modify it
+ * under  the terms of	the GNU General	 Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <asm/irq_cpu.h>
+
+#include <loongson1.h>
+#include <irq.h>
+
+#define LS1X_INTC_REG(n, x) \
+		((void __iomem *)KSEG1ADDR(LS1X_INTC_BASE + (n * 0x18) + (x)))
+
+#define LS1X_INTC_INTISR(n)		LS1X_INTC_REG(n, 0x0)
+#define LS1X_INTC_INTIEN(n)		LS1X_INTC_REG(n, 0x4)
+#define LS1X_INTC_INTSET(n)		LS1X_INTC_REG(n, 0x8)
+#define LS1X_INTC_INTCLR(n)		LS1X_INTC_REG(n, 0xc)
+#define LS1X_INTC_INTPOL(n)		LS1X_INTC_REG(n, 0x10)
+#define LS1X_INTC_INTEDGE(n)		LS1X_INTC_REG(n, 0x14)
+
+static void ls1x_irq_ack(struct irq_data *d)
+{
+	unsigned int bit = (d->irq - LS1X_IRQ_BASE) & 0x1f;
+	unsigned int n = (d->irq - LS1X_IRQ_BASE) >> 5;
+
+	__raw_writel(__raw_readl(LS1X_INTC_INTCLR(n))
+			| (1 << bit), LS1X_INTC_INTCLR(n));
+}
+
+static void ls1x_irq_mask(struct irq_data *d)
+{
+	unsigned int bit = (d->irq - LS1X_IRQ_BASE) & 0x1f;
+	unsigned int n = (d->irq - LS1X_IRQ_BASE) >> 5;
+
+	__raw_writel(__raw_readl(LS1X_INTC_INTIEN(n))
+			& ~(1 << bit), LS1X_INTC_INTIEN(n));
+}
+
+static void ls1x_irq_mask_ack(struct irq_data *d)
+{
+	unsigned int bit = (d->irq - LS1X_IRQ_BASE) & 0x1f;
+	unsigned int n = (d->irq - LS1X_IRQ_BASE) >> 5;
+
+	__raw_writel(__raw_readl(LS1X_INTC_INTIEN(n))
+			& ~(1 << bit), LS1X_INTC_INTIEN(n));
+	__raw_writel(__raw_readl(LS1X_INTC_INTCLR(n))
+			| (1 << bit), LS1X_INTC_INTCLR(n));
+}
+
+static void ls1x_irq_unmask(struct irq_data *d)
+{
+	unsigned int bit = (d->irq - LS1X_IRQ_BASE) & 0x1f;
+	unsigned int n = (d->irq - LS1X_IRQ_BASE) >> 5;
+
+	__raw_writel(__raw_readl(LS1X_INTC_INTIEN(n))
+			| (1 << bit), LS1X_INTC_INTIEN(n));
+}
+
+static struct irq_chip ls1x_irq_chip = {
+	.name		= "LS1X-INTC",
+	.irq_ack	= ls1x_irq_ack,
+	.irq_mask	= ls1x_irq_mask,
+	.irq_mask_ack	= ls1x_irq_mask_ack,
+	.irq_unmask	= ls1x_irq_unmask,
+};
+
+static void ls1x_irq_dispatch(int n)
+{
+	u32 int_status, irq;
+
+	/* Get pending sources, masked by current enables */
+	int_status = __raw_readl(LS1X_INTC_INTISR(n)) &
+			__raw_readl(LS1X_INTC_INTIEN(n));
+
+	if (int_status) {
+		irq = LS1X_IRQ(n, __ffs(int_status));
+		do_IRQ(irq);
+	}
+}
+
+asmlinkage void plat_irq_dispatch(void)
+{
+	unsigned int pending;
+
+	pending = read_c0_cause() & read_c0_status() & ST0_IM;
+
+	if (pending & CAUSEF_IP7)
+		do_IRQ(TIMER_IRQ);
+	else if (pending & CAUSEF_IP2)
+		ls1x_irq_dispatch(0); /* INT0 */
+	else if (pending & CAUSEF_IP3)
+		ls1x_irq_dispatch(1); /* INT1 */
+	else if (pending & CAUSEF_IP4)
+		ls1x_irq_dispatch(2); /* INT2 */
+	else if (pending & CAUSEF_IP5)
+		ls1x_irq_dispatch(3); /* INT3 */
+	else if (pending & CAUSEF_IP6)
+		ls1x_irq_dispatch(4); /* INT4 */
+	else
+		spurious_interrupt();
+
+}
+
+struct irqaction cascade_irqaction = {
+	.handler = no_action,
+	.name = "cascade",
+	.flags = IRQF_NO_THREAD,
+};
+
+static void __init ls1x_irq_init(int base)
+{
+	int n;
+
+	/* Disable interrupts and clear pending,
+	 * setup all IRQs as high level triggered
+	 */
+	for (n = 0; n < 4; n++) {
+		__raw_writel(0x0, LS1X_INTC_INTIEN(n));
+		__raw_writel(0xffffffff, LS1X_INTC_INTCLR(n));
+		__raw_writel(0xffffffff, LS1X_INTC_INTPOL(n));
+		/* set DMA0, DMA1 and DMA2 to edge trigger */
+		__raw_writel(n ? 0x0 : 0xe000, LS1X_INTC_INTEDGE(n));
+	}
+
+
+	for (n = base; n < LS1X_IRQS; n++) {
+		irq_set_chip_and_handler(n, &ls1x_irq_chip,
+					 handle_level_irq);
+	}
+
+	setup_irq(INT0_IRQ, &cascade_irqaction);
+	setup_irq(INT1_IRQ, &cascade_irqaction);
+	setup_irq(INT2_IRQ, &cascade_irqaction);
+	setup_irq(INT3_IRQ, &cascade_irqaction);
+}
+
+void __init arch_init_irq(void)
+{
+	mips_cpu_irq_init();
+	ls1x_irq_init(LS1X_IRQ_BASE);
+}