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/ralink/early_printk.c b/kernel/arch/mips/ralink/early_printk.c
new file mode 100644
index 000000000..255d695ec
--- /dev/null
+++ b/kernel/arch/mips/ralink/early_printk.c
@@ -0,0 +1,63 @@
+/*
+ *  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.
+ *
+ *  Copyright (C) 2011-2012 Gabor Juhos <juhosg@openwrt.org>
+ */
+
+#include <linux/io.h>
+#include <linux/serial_reg.h>
+
+#include <asm/addrspace.h>
+
+#ifdef CONFIG_SOC_RT288X
+#define EARLY_UART_BASE		0x300c00
+#define CHIPID_BASE		0x300004
+#elif defined(CONFIG_SOC_MT7621)
+#define EARLY_UART_BASE		0x1E000c00
+#define CHIPID_BASE		0x1E000004
+#else
+#define EARLY_UART_BASE		0x10000c00
+#define CHIPID_BASE		0x10000004
+#endif
+
+#define MT7628_CHIP_NAME1	0x20203832
+
+#define UART_REG_TX		0x04
+#define UART_REG_LSR		0x14
+#define UART_REG_LSR_RT2880	0x1c
+
+static __iomem void *uart_membase = (__iomem void *) KSEG1ADDR(EARLY_UART_BASE);
+static __iomem void *chipid_membase = (__iomem void *) KSEG1ADDR(CHIPID_BASE);
+
+static inline void uart_w32(u32 val, unsigned reg)
+{
+	__raw_writel(val, uart_membase + reg);
+}
+
+static inline u32 uart_r32(unsigned reg)
+{
+	return __raw_readl(uart_membase + reg);
+}
+
+static inline int soc_is_mt7628(void)
+{
+	return IS_ENABLED(CONFIG_SOC_MT7620) &&
+		(__raw_readl(chipid_membase) == MT7628_CHIP_NAME1);
+}
+
+void prom_putchar(unsigned char ch)
+{
+	if (IS_ENABLED(CONFIG_SOC_MT7621) || soc_is_mt7628()) {
+		uart_w32(ch, UART_TX);
+		while ((uart_r32(UART_REG_LSR) & UART_LSR_THRE) == 0)
+			;
+	} else {
+		while ((uart_r32(UART_REG_LSR_RT2880) & UART_LSR_THRE) == 0)
+			;
+		uart_w32(ch, UART_REG_TX);
+		while ((uart_r32(UART_REG_LSR_RT2880) & UART_LSR_THRE) == 0)
+			;
+	}
+}