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, 317 insertions, 0 deletions

diff --git a/kernel/arch/xtensa/mm/cache.c b/kernel/arch/xtensa/mm/cache.c
new file mode 100644
index 000000000..d75aa1476
--- /dev/null
+++ b/kernel/arch/xtensa/mm/cache.c
@@ -0,0 +1,317 @@
+/*
+ * arch/xtensa/mm/cache.c
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001-2006 Tensilica Inc.
+ *
+ * Chris Zankel	<chris@zankel.net>
+ * Joe Taylor
+ * Marc Gauthier
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/bootmem.h>
+#include <linux/swap.h>
+#include <linux/pagemap.h>
+
+#include <asm/bootparam.h>
+#include <asm/mmu_context.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include <asm/page.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+
+//#define printd(x...) printk(x)
+#define printd(x...) do { } while(0)
+
+/* 
+ * Note:
+ * The kernel provides one architecture bit PG_arch_1 in the page flags that 
+ * can be used for cache coherency.
+ *
+ * I$-D$ coherency.
+ *
+ * The Xtensa architecture doesn't keep the instruction cache coherent with
+ * the data cache. We use the architecture bit to indicate if the caches
+ * are coherent. The kernel clears this bit whenever a page is added to the
+ * page cache. At that time, the caches might not be in sync. We, therefore,
+ * define this flag as 'clean' if set.
+ *
+ * D-cache aliasing.
+ *
+ * With cache aliasing, we have to always flush the cache when pages are
+ * unmapped (see tlb_start_vma(). So, we use this flag to indicate a dirty
+ * page.
+ * 
+ *
+ *
+ */
+
+#if (DCACHE_WAY_SIZE > PAGE_SIZE)
+static inline void kmap_invalidate_coherent(struct page *page,
+					    unsigned long vaddr)
+{
+	if (!DCACHE_ALIAS_EQ(page_to_phys(page), vaddr)) {
+		unsigned long kvaddr;
+
+		if (!PageHighMem(page)) {
+			kvaddr = (unsigned long)page_to_virt(page);
+
+			__invalidate_dcache_page(kvaddr);
+		} else {
+			kvaddr = TLBTEMP_BASE_1 +
+				(page_to_phys(page) & DCACHE_ALIAS_MASK);
+
+			__invalidate_dcache_page_alias(kvaddr,
+						       page_to_phys(page));
+		}
+	}
+}
+
+static inline void *coherent_kvaddr(struct page *page, unsigned long base,
+				    unsigned long vaddr, unsigned long *paddr)
+{
+	if (PageHighMem(page) || !DCACHE_ALIAS_EQ(page_to_phys(page), vaddr)) {
+		*paddr = page_to_phys(page);
+		return (void *)(base + (vaddr & DCACHE_ALIAS_MASK));
+	} else {
+		*paddr = 0;
+		return page_to_virt(page);
+	}
+}
+
+void clear_user_highpage(struct page *page, unsigned long vaddr)
+{
+	unsigned long paddr;
+	void *kvaddr = coherent_kvaddr(page, TLBTEMP_BASE_1, vaddr, &paddr);
+
+	pagefault_disable();
+	kmap_invalidate_coherent(page, vaddr);
+	set_bit(PG_arch_1, &page->flags);
+	clear_page_alias(kvaddr, paddr);
+	pagefault_enable();
+}
+
+void copy_user_highpage(struct page *dst, struct page *src,
+			unsigned long vaddr, struct vm_area_struct *vma)
+{
+	unsigned long dst_paddr, src_paddr;
+	void *dst_vaddr = coherent_kvaddr(dst, TLBTEMP_BASE_1, vaddr,
+					  &dst_paddr);
+	void *src_vaddr = coherent_kvaddr(src, TLBTEMP_BASE_2, vaddr,
+					  &src_paddr);
+
+	pagefault_disable();
+	kmap_invalidate_coherent(dst, vaddr);
+	set_bit(PG_arch_1, &dst->flags);
+	copy_page_alias(dst_vaddr, src_vaddr, dst_paddr, src_paddr);
+	pagefault_enable();
+}
+
+#endif /* DCACHE_WAY_SIZE > PAGE_SIZE */
+
+#if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DCACHE_IS_WRITEBACK
+
+/*
+ * Any time the kernel writes to a user page cache page, or it is about to
+ * read from a page cache page this routine is called.
+ *
+ */
+
+void flush_dcache_page(struct page *page)
+{
+	struct address_space *mapping = page_mapping(page);
+
+	/*
+	 * If we have a mapping but the page is not mapped to user-space
+	 * yet, we simply mark this page dirty and defer flushing the 
+	 * caches until update_mmu().
+	 */
+
+	if (mapping && !mapping_mapped(mapping)) {
+		if (!test_bit(PG_arch_1, &page->flags))
+			set_bit(PG_arch_1, &page->flags);
+		return;
+
+	} else {
+
+		unsigned long phys = page_to_phys(page);
+		unsigned long temp = page->index << PAGE_SHIFT;
+		unsigned long alias = !(DCACHE_ALIAS_EQ(temp, phys));
+		unsigned long virt;
+
+		/* 
+		 * Flush the page in kernel space and user space.
+		 * Note that we can omit that step if aliasing is not
+		 * an issue, but we do have to synchronize I$ and D$
+		 * if we have a mapping.
+		 */
+
+		if (!alias && !mapping)
+			return;
+
+		virt = TLBTEMP_BASE_1 + (phys & DCACHE_ALIAS_MASK);
+		__flush_invalidate_dcache_page_alias(virt, phys);
+
+		virt = TLBTEMP_BASE_1 + (temp & DCACHE_ALIAS_MASK);
+
+		if (alias)
+			__flush_invalidate_dcache_page_alias(virt, phys);
+
+		if (mapping)
+			__invalidate_icache_page_alias(virt, phys);
+	}
+
+	/* There shouldn't be an entry in the cache for this page anymore. */
+}
+
+
+/*
+ * For now, flush the whole cache. FIXME??
+ */
+
+void local_flush_cache_range(struct vm_area_struct *vma,
+		       unsigned long start, unsigned long end)
+{
+	__flush_invalidate_dcache_all();
+	__invalidate_icache_all();
+}
+
+/* 
+ * Remove any entry in the cache for this page. 
+ *
+ * Note that this function is only called for user pages, so use the
+ * alias versions of the cache flush functions.
+ */
+
+void local_flush_cache_page(struct vm_area_struct *vma, unsigned long address,
+		      unsigned long pfn)
+{
+	/* Note that we have to use the 'alias' address to avoid multi-hit */
+
+	unsigned long phys = page_to_phys(pfn_to_page(pfn));
+	unsigned long virt = TLBTEMP_BASE_1 + (address & DCACHE_ALIAS_MASK);
+
+	__flush_invalidate_dcache_page_alias(virt, phys);
+	__invalidate_icache_page_alias(virt, phys);
+}
+
+#endif
+
+void
+update_mmu_cache(struct vm_area_struct * vma, unsigned long addr, pte_t *ptep)
+{
+	unsigned long pfn = pte_pfn(*ptep);
+	struct page *page;
+
+	if (!pfn_valid(pfn))
+		return;
+
+	page = pfn_to_page(pfn);
+
+	/* Invalidate old entry in TLBs */
+
+	flush_tlb_page(vma, addr);
+
+#if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DCACHE_IS_WRITEBACK
+
+	if (!PageReserved(page) && test_bit(PG_arch_1, &page->flags)) {
+		unsigned long phys = page_to_phys(page);
+		unsigned long tmp;
+
+		tmp = TLBTEMP_BASE_1 + (phys & DCACHE_ALIAS_MASK);
+		__flush_invalidate_dcache_page_alias(tmp, phys);
+		tmp = TLBTEMP_BASE_1 + (addr & DCACHE_ALIAS_MASK);
+		__flush_invalidate_dcache_page_alias(tmp, phys);
+		__invalidate_icache_page_alias(tmp, phys);
+
+		clear_bit(PG_arch_1, &page->flags);
+	}
+#else
+	if (!PageReserved(page) && !test_bit(PG_arch_1, &page->flags)
+	    && (vma->vm_flags & VM_EXEC) != 0) {
+		unsigned long paddr = (unsigned long)kmap_atomic(page);
+		__flush_dcache_page(paddr);
+		__invalidate_icache_page(paddr);
+		set_bit(PG_arch_1, &page->flags);
+		kunmap_atomic((void *)paddr);
+	}
+#endif
+}
+
+/*
+ * access_process_vm() has called get_user_pages(), which has done a
+ * flush_dcache_page() on the page.
+ */
+
+#if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DCACHE_IS_WRITEBACK
+
+void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
+		unsigned long vaddr, void *dst, const void *src,
+		unsigned long len)
+{
+	unsigned long phys = page_to_phys(page);
+	unsigned long alias = !(DCACHE_ALIAS_EQ(vaddr, phys));
+
+	/* Flush and invalidate user page if aliased. */
+
+	if (alias) {
+		unsigned long t = TLBTEMP_BASE_1 + (vaddr & DCACHE_ALIAS_MASK);
+		__flush_invalidate_dcache_page_alias(t, phys);
+	}
+
+	/* Copy data */
+	
+	memcpy(dst, src, len);
+
+	/*
+	 * Flush and invalidate kernel page if aliased and synchronize 
+	 * data and instruction caches for executable pages. 
+	 */
+
+	if (alias) {
+		unsigned long t = TLBTEMP_BASE_1 + (vaddr & DCACHE_ALIAS_MASK);
+
+		__flush_invalidate_dcache_range((unsigned long) dst, len);
+		if ((vma->vm_flags & VM_EXEC) != 0)
+			__invalidate_icache_page_alias(t, phys);
+
+	} else if ((vma->vm_flags & VM_EXEC) != 0) {
+		__flush_dcache_range((unsigned long)dst,len);
+		__invalidate_icache_range((unsigned long) dst, len);
+	}
+}
+
+extern void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
+		unsigned long vaddr, void *dst, const void *src,
+		unsigned long len)
+{
+	unsigned long phys = page_to_phys(page);
+	unsigned long alias = !(DCACHE_ALIAS_EQ(vaddr, phys));
+
+	/*
+	 * Flush user page if aliased. 
+	 * (Note: a simply flush would be sufficient) 
+	 */
+
+	if (alias) {
+		unsigned long t = TLBTEMP_BASE_1 + (vaddr & DCACHE_ALIAS_MASK);
+		__flush_invalidate_dcache_page_alias(t, phys);
+	}
+
+	memcpy(dst, src, len);
+}
+
+#endif