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, 122 insertions, 0 deletions

diff --git a/kernel/arch/blackfin/mm/init.c b/kernel/arch/blackfin/mm/init.c
new file mode 100644
index 000000000..166842de3
--- /dev/null
+++ b/kernel/arch/blackfin/mm/init.c
@@ -0,0 +1,122 @@
+/*
+ * Copyright 2004-2009 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/gfp.h>
+#include <linux/swap.h>
+#include <linux/bootmem.h>
+#include <linux/uaccess.h>
+#include <linux/export.h>
+#include <asm/bfin-global.h>
+#include <asm/pda.h>
+#include <asm/cplbinit.h>
+#include <asm/early_printk.h>
+#include "blackfin_sram.h"
+
+/*
+ * ZERO_PAGE is a special page that is used for zero-initialized data and COW.
+ * Let the bss do its zero-init magic so we don't have to do it ourselves.
+ */
+char empty_zero_page[PAGE_SIZE] __attribute__((aligned(PAGE_SIZE)));
+EXPORT_SYMBOL(empty_zero_page);
+
+#ifndef CONFIG_EXCEPTION_L1_SCRATCH
+#if defined CONFIG_SYSCALL_TAB_L1
+__attribute__((l1_data))
+#endif
+static unsigned long exception_stack[NR_CPUS][1024];
+#endif
+
+struct blackfin_pda cpu_pda[NR_CPUS];
+EXPORT_SYMBOL(cpu_pda);
+
+/*
+ * paging_init() continues the virtual memory environment setup which
+ * was begun by the code in arch/head.S.
+ * The parameters are pointers to where to stick the starting and ending
+ * addresses  of available kernel virtual memory.
+ */
+void __init paging_init(void)
+{
+	/*
+	 * make sure start_mem is page aligned, otherwise bootmem and
+	 * page_alloc get different views of the world
+	 */
+	unsigned long end_mem = memory_end & PAGE_MASK;
+
+	unsigned long zones_size[MAX_NR_ZONES] = {
+		[0] = 0,
+		[ZONE_DMA] = (end_mem - CONFIG_PHY_RAM_BASE_ADDRESS) >> PAGE_SHIFT,
+		[ZONE_NORMAL] = 0,
+#ifdef CONFIG_HIGHMEM
+		[ZONE_HIGHMEM] = 0,
+#endif
+	};
+
+	/* Set up SFC/DFC registers (user data space) */
+	set_fs(KERNEL_DS);
+
+	pr_debug("free_area_init -> start_mem is %#lx virtual_end is %#lx\n",
+	        PAGE_ALIGN(memory_start), end_mem);
+	free_area_init_node(0, zones_size,
+		CONFIG_PHY_RAM_BASE_ADDRESS >> PAGE_SHIFT, NULL);
+}
+
+asmlinkage void __init init_pda(void)
+{
+	unsigned int cpu = raw_smp_processor_id();
+
+	early_shadow_stamp();
+
+	/* Initialize the PDA fields holding references to other parts
+	   of the memory. The content of such memory is still
+	   undefined at the time of the call, we are only setting up
+	   valid pointers to it. */
+	memset(&cpu_pda[cpu], 0, sizeof(cpu_pda[cpu]));
+
+#ifdef CONFIG_EXCEPTION_L1_SCRATCH
+	cpu_pda[cpu].ex_stack = (unsigned long *)(L1_SCRATCH_START + \
+					L1_SCRATCH_LENGTH);
+#else
+	cpu_pda[cpu].ex_stack = exception_stack[cpu + 1];
+#endif
+
+#ifdef CONFIG_SMP
+	cpu_pda[cpu].imask = 0x1f;
+#endif
+}
+
+void __init mem_init(void)
+{
+	char buf[64];
+
+	high_memory = (void *)(memory_end & PAGE_MASK);
+	max_mapnr = MAP_NR(high_memory);
+	printk(KERN_DEBUG "Kernel managed physical pages: %lu\n", max_mapnr);
+
+	/* This will put all low memory onto the freelists. */
+	free_all_bootmem();
+
+	snprintf(buf, sizeof(buf) - 1, "%uK DMA", DMA_UNCACHED_REGION >> 10);
+	mem_init_print_info(buf);
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void __init free_initrd_mem(unsigned long start, unsigned long end)
+{
+#ifndef CONFIG_MPU
+	free_reserved_area((void *)start, (void *)end, -1, "initrd");
+#endif
+}
+#endif
+
+void __init_refok free_initmem(void)
+{
+#if defined CONFIG_RAMKERNEL && !defined CONFIG_MPU
+	free_initmem_default(-1);
+	if (memory_start == (unsigned long)(&__init_end))
+		memory_start = (unsigned long)(&__init_begin);
+#endif
+}