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, 93 insertions, 0 deletions

diff --git a/kernel/arch/hexagon/mm/vm_tlb.c b/kernel/arch/hexagon/mm/vm_tlb.c
new file mode 100644
index 000000000..9647d00cb
--- /dev/null
+++ b/kernel/arch/hexagon/mm/vm_tlb.c
@@ -0,0 +1,93 @@
+/*
+ * Hexagon Virtual Machine TLB functions
+ *
+ * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+/*
+ * The Hexagon Virtual Machine conceals the real workings of
+ * the TLB, but there are one or two functions that need to
+ * be instantiated for it, differently from a native build.
+ */
+#include <linux/mm.h>
+#include <asm/page.h>
+#include <asm/hexagon_vm.h>
+
+/*
+ * Initial VM implementation has only one map active at a time, with
+ * TLB purgings on changes.  So either we're nuking the current map,
+ * or it's a no-op.  This operation is messy on true SMPs where other
+ * processors must be induced to flush the copies in their local TLBs,
+ * but Hexagon thread-based virtual processors share the same MMU.
+ */
+void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
+			unsigned long end)
+{
+	struct mm_struct *mm = vma->vm_mm;
+
+	if (mm->context.ptbase == current->active_mm->context.ptbase)
+		__vmclrmap((void *)start, end - start);
+}
+
+/*
+ * Flush a page from the kernel virtual map - used by highmem
+ */
+void flush_tlb_one(unsigned long vaddr)
+{
+	__vmclrmap((void *)vaddr, PAGE_SIZE);
+}
+
+/*
+ * Flush all TLBs across all CPUs, virtual or real.
+ * A single Hexagon core has 6 thread contexts but
+ * only one TLB.
+ */
+void tlb_flush_all(void)
+{
+	/*  should probably use that fixaddr end or whateve label  */
+	__vmclrmap(0, 0xffff0000);
+}
+
+/*
+ * Flush TLB entries associated with a given mm_struct mapping.
+ */
+void flush_tlb_mm(struct mm_struct *mm)
+{
+	/* Current Virtual Machine has only one map active at a time */
+	if (current->active_mm->context.ptbase == mm->context.ptbase)
+		tlb_flush_all();
+}
+
+/*
+ * Flush TLB state associated with a page of a vma.
+ */
+void flush_tlb_page(struct vm_area_struct *vma, unsigned long vaddr)
+{
+	struct mm_struct *mm = vma->vm_mm;
+
+	if (mm->context.ptbase  == current->active_mm->context.ptbase)
+		__vmclrmap((void *)vaddr, PAGE_SIZE);
+}
+
+/*
+ * Flush TLB entries associated with a kernel address range.
+ * Like flush range, but without the check on the vma->vm_mm.
+ */
+void flush_tlb_kernel_range(unsigned long start, unsigned long end)
+{
+		__vmclrmap((void *)start, end - start);
+}