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/arm64/mm/flush.c b/kernel/arch/arm64/mm/flush.c
new file mode 100644
index 000000000..b6f14e8d2
--- /dev/null
+++ b/kernel/arch/arm64/mm/flush.c
@@ -0,0 +1,122 @@
+/*
+ * Based on arch/arm/mm/flush.c
+ *
+ * Copyright (C) 1995-2002 Russell King
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * 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.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+
+#include <asm/cacheflush.h>
+#include <asm/cachetype.h>
+#include <asm/tlbflush.h>
+
+#include "mm.h"
+
+void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
+		       unsigned long end)
+{
+	if (vma->vm_flags & VM_EXEC)
+		__flush_icache_all();
+}
+
+static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
+				unsigned long uaddr, void *kaddr,
+				unsigned long len)
+{
+	if (vma->vm_flags & VM_EXEC) {
+		unsigned long addr = (unsigned long)kaddr;
+		if (icache_is_aliasing()) {
+			__flush_dcache_area(kaddr, len);
+			__flush_icache_all();
+		} else {
+			flush_icache_range(addr, addr + len);
+		}
+	}
+}
+
+/*
+ * Copy user data from/to a page which is mapped into a different processes
+ * address space.  Really, we want to allow our "user space" model to handle
+ * this.
+ *
+ * Note that this code needs to run on the current CPU.
+ */
+void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
+		       unsigned long uaddr, void *dst, const void *src,
+		       unsigned long len)
+{
+#ifdef CONFIG_SMP
+	preempt_disable();
+#endif
+	memcpy(dst, src, len);
+	flush_ptrace_access(vma, page, uaddr, dst, len);
+#ifdef CONFIG_SMP
+	preempt_enable();
+#endif
+}
+
+void __sync_icache_dcache(pte_t pte, unsigned long addr)
+{
+	struct page *page = pte_page(pte);
+
+	/* no flushing needed for anonymous pages */
+	if (!page_mapping(page))
+		return;
+
+	if (!test_and_set_bit(PG_dcache_clean, &page->flags)) {
+		__flush_dcache_area(page_address(page),
+				PAGE_SIZE << compound_order(page));
+		__flush_icache_all();
+	} else if (icache_is_aivivt()) {
+		__flush_icache_all();
+	}
+}
+
+/*
+ * This function is called when a page has been modified by the kernel. Mark
+ * it as dirty for later flushing when mapped in user space (if executable,
+ * see __sync_icache_dcache).
+ */
+void flush_dcache_page(struct page *page)
+{
+	if (test_bit(PG_dcache_clean, &page->flags))
+		clear_bit(PG_dcache_clean, &page->flags);
+}
+EXPORT_SYMBOL(flush_dcache_page);
+
+/*
+ * Additional functions defined in assembly.
+ */
+EXPORT_SYMBOL(flush_cache_all);
+EXPORT_SYMBOL(flush_icache_range);
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#ifdef CONFIG_HAVE_RCU_TABLE_FREE
+void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
+			  pmd_t *pmdp)
+{
+	pmd_t pmd = pmd_mksplitting(*pmdp);
+
+	VM_BUG_ON(address & ~PMD_MASK);
+	set_pmd_at(vma->vm_mm, address, pmdp, pmd);
+
+	/* dummy IPI to serialise against fast_gup */
+	kick_all_cpus_sync();
+}
+#endif /* CONFIG_HAVE_RCU_TABLE_FREE */
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */