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>

3 files changed, 227 insertions, 0 deletions

diff --git a/kernel/arch/c6x/mm/Makefile b/kernel/arch/c6x/mm/Makefile
new file mode 100644
index 000000000..136a97576
--- /dev/null
+++ b/kernel/arch/c6x/mm/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile for the linux c6x-specific parts of the memory manager.
+#
+
+obj-y := init.o dma-coherent.o
diff --git a/kernel/arch/c6x/mm/dma-coherent.c b/kernel/arch/c6x/mm/dma-coherent.c
new file mode 100644
index 000000000..4187e5180
--- /dev/null
+++ b/kernel/arch/c6x/mm/dma-coherent.c
@@ -0,0 +1,143 @@
+/*
+ *  Port on Texas Instruments TMS320C6x architecture
+ *
+ *  Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated
+ *  Author: Aurelien Jacquiot <aurelien.jacquiot@ti.com>
+ *
+ *  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.
+ *
+ *  DMA uncached mapping support.
+ *
+ *  Using code pulled from ARM
+ *  Copyright (C) 2000-2004 Russell King
+ *
+ */
+#include <linux/slab.h>
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/dma-mapping.h>
+#include <linux/memblock.h>
+
+#include <asm/page.h>
+
+/*
+ * DMA coherent memory management, can be redefined using the memdma=
+ * kernel command line
+ */
+
+/* none by default */
+static phys_addr_t dma_base;
+static u32 dma_size;
+static u32 dma_pages;
+
+static unsigned long *dma_bitmap;
+
+/* bitmap lock */
+static DEFINE_SPINLOCK(dma_lock);
+
+/*
+ * Return a DMA coherent and contiguous memory chunk from the DMA memory
+ */
+static inline u32 __alloc_dma_pages(int order)
+{
+	unsigned long flags;
+	u32 pos;
+
+	spin_lock_irqsave(&dma_lock, flags);
+	pos = bitmap_find_free_region(dma_bitmap, dma_pages, order);
+	spin_unlock_irqrestore(&dma_lock, flags);
+
+	return dma_base + (pos << PAGE_SHIFT);
+}
+
+static void __free_dma_pages(u32 addr, int order)
+{
+	unsigned long flags;
+	u32 pos = (addr - dma_base) >> PAGE_SHIFT;
+
+	if (addr < dma_base || (pos + (1 << order)) >= dma_pages) {
+		printk(KERN_ERR "%s: freeing outside range.\n", __func__);
+		BUG();
+	}
+
+	spin_lock_irqsave(&dma_lock, flags);
+	bitmap_release_region(dma_bitmap, pos, order);
+	spin_unlock_irqrestore(&dma_lock, flags);
+}
+
+/*
+ * Allocate DMA coherent memory space and return both the kernel
+ * virtual and DMA address for that space.
+ */
+void *dma_alloc_coherent(struct device *dev, size_t size,
+			 dma_addr_t *handle, gfp_t gfp)
+{
+	u32 paddr;
+	int order;
+
+	if (!dma_size || !size)
+		return NULL;
+
+	order = get_count_order(((size - 1) >> PAGE_SHIFT) + 1);
+
+	paddr = __alloc_dma_pages(order);
+
+	if (handle)
+		*handle = paddr;
+
+	if (!paddr)
+		return NULL;
+
+	return phys_to_virt(paddr);
+}
+EXPORT_SYMBOL(dma_alloc_coherent);
+
+/*
+ * Free DMA coherent memory as defined by the above mapping.
+ */
+void dma_free_coherent(struct device *dev, size_t size, void *vaddr,
+		       dma_addr_t dma_handle)
+{
+	int order;
+
+	if (!dma_size || !size)
+		return;
+
+	order = get_count_order(((size - 1) >> PAGE_SHIFT) + 1);
+
+	__free_dma_pages(virt_to_phys(vaddr), order);
+}
+EXPORT_SYMBOL(dma_free_coherent);
+
+/*
+ * Initialise the coherent DMA memory allocator using the given uncached region.
+ */
+void __init coherent_mem_init(phys_addr_t start, u32 size)
+{
+	phys_addr_t bitmap_phys;
+
+	if (!size)
+		return;
+
+	printk(KERN_INFO
+	       "Coherent memory (DMA) region start=0x%x size=0x%x\n",
+	       start, size);
+
+	dma_base = start;
+	dma_size = size;
+
+	/* allocate bitmap */
+	dma_pages = dma_size >> PAGE_SHIFT;
+	if (dma_size & (PAGE_SIZE - 1))
+		++dma_pages;
+
+	bitmap_phys = memblock_alloc(BITS_TO_LONGS(dma_pages) * sizeof(long),
+				     sizeof(long));
+
+	dma_bitmap = phys_to_virt(bitmap_phys);
+	memset(dma_bitmap, 0, dma_pages * PAGE_SIZE);
+}
diff --git a/kernel/arch/c6x/mm/init.c b/kernel/arch/c6x/mm/init.c
new file mode 100644
index 000000000..63f5560d6
--- /dev/null
+++ b/kernel/arch/c6x/mm/init.c
@@ -0,0 +1,79 @@
+/*
+ *  Port on Texas Instruments TMS320C6x architecture
+ *
+ *  Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated
+ *  Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
+ *
+ *  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/mm.h>
+#include <linux/swap.h>
+#include <linux/module.h>
+#include <linux/bootmem.h>
+#ifdef CONFIG_BLK_DEV_RAM
+#include <linux/blkdev.h>
+#endif
+#include <linux/initrd.h>
+
+#include <asm/sections.h>
+#include <asm/uaccess.h>
+
+/*
+ * ZERO_PAGE is a special page that is used for zero-initialized
+ * data and COW.
+ */
+unsigned long empty_zero_page;
+EXPORT_SYMBOL(empty_zero_page);
+
+/*
+ * 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)
+{
+	struct pglist_data *pgdat = NODE_DATA(0);
+	unsigned long zones_size[MAX_NR_ZONES] = {0, };
+
+	empty_zero_page      = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
+	memset((void *)empty_zero_page, 0, PAGE_SIZE);
+
+	/*
+	 * Set up user data space
+	 */
+	set_fs(KERNEL_DS);
+
+	/*
+	 * Define zones
+	 */
+	zones_size[ZONE_NORMAL] = (memory_end - PAGE_OFFSET) >> PAGE_SHIFT;
+	pgdat->node_zones[ZONE_NORMAL].zone_start_pfn =
+		__pa(PAGE_OFFSET) >> PAGE_SHIFT;
+
+	free_area_init(zones_size);
+}
+
+void __init mem_init(void)
+{
+	high_memory = (void *)(memory_end & PAGE_MASK);
+
+	/* this will put all memory onto the freelists */
+	free_all_bootmem();
+
+	mem_init_print_info(NULL);
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void __init free_initrd_mem(unsigned long start, unsigned long end)
+{
+	free_reserved_area((void *)start, (void *)end, -1, "initrd");
+}
+#endif
+
+void __init free_initmem(void)
+{
+	free_initmem_default(-1);
+}