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>

8 files changed, 1981 insertions, 0 deletions

diff --git a/kernel/arch/xtensa/mm/Makefile b/kernel/arch/xtensa/mm/Makefile
new file mode 100644
index 000000000..e601e2fbe
--- /dev/null
+++ b/kernel/arch/xtensa/mm/Makefile
@@ -0,0 +1,7 @@
+#
+# Makefile for the Linux/Xtensa-specific parts of the memory manager.
+#
+
+obj-y			:= init.o misc.o
+obj-$(CONFIG_MMU)	+= cache.o fault.o mmu.o tlb.o
+obj-$(CONFIG_HIGHMEM)	+= highmem.o
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
diff --git a/kernel/arch/xtensa/mm/fault.c b/kernel/arch/xtensa/mm/fault.c
new file mode 100644
index 000000000..83a44a33c
--- /dev/null
+++ b/kernel/arch/xtensa/mm/fault.c
@@ -0,0 +1,260 @@
+// TODO VM_EXEC flag work-around, cache aliasing
+/*
+ * arch/xtensa/mm/fault.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 - 2010 Tensilica Inc.
+ *
+ * Chris Zankel <chris@zankel.net>
+ * Joe Taylor	<joe@tensilica.com, joetylr@yahoo.com>
+ */
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/hardirq.h>
+#include <linux/uaccess.h>
+#include <asm/mmu_context.h>
+#include <asm/cacheflush.h>
+#include <asm/hardirq.h>
+#include <asm/pgalloc.h>
+
+DEFINE_PER_CPU(unsigned long, asid_cache) = ASID_USER_FIRST;
+void bad_page_fault(struct pt_regs*, unsigned long, int);
+
+#undef DEBUG_PAGE_FAULT
+
+/*
+ * This routine handles page faults.  It determines the address,
+ * and the problem, and then passes it off to one of the appropriate
+ * routines.
+ *
+ * Note: does not handle Miss and MultiHit.
+ */
+
+void do_page_fault(struct pt_regs *regs)
+{
+	struct vm_area_struct * vma;
+	struct mm_struct *mm = current->mm;
+	unsigned int exccause = regs->exccause;
+	unsigned int address = regs->excvaddr;
+	siginfo_t info;
+
+	int is_write, is_exec;
+	int fault;
+	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
+
+	info.si_code = SEGV_MAPERR;
+
+	/* We fault-in kernel-space virtual memory on-demand. The
+	 * 'reference' page table is init_mm.pgd.
+	 */
+	if (address >= TASK_SIZE && !user_mode(regs))
+		goto vmalloc_fault;
+
+	/* If we're in an interrupt or have no user
+	 * context, we must not take the fault..
+	 */
+	if (faulthandler_disabled() || !mm) {
+		bad_page_fault(regs, address, SIGSEGV);
+		return;
+	}
+
+	is_write = (exccause == EXCCAUSE_STORE_CACHE_ATTRIBUTE) ? 1 : 0;
+	is_exec =  (exccause == EXCCAUSE_ITLB_PRIVILEGE ||
+		    exccause == EXCCAUSE_ITLB_MISS ||
+		    exccause == EXCCAUSE_FETCH_CACHE_ATTRIBUTE) ? 1 : 0;
+
+#ifdef DEBUG_PAGE_FAULT
+	printk("[%s:%d:%08x:%d:%08x:%s%s]\n", current->comm, current->pid,
+	       address, exccause, regs->pc, is_write? "w":"", is_exec? "x":"");
+#endif
+
+	if (user_mode(regs))
+		flags |= FAULT_FLAG_USER;
+retry:
+	down_read(&mm->mmap_sem);
+	vma = find_vma(mm, address);
+
+	if (!vma)
+		goto bad_area;
+	if (vma->vm_start <= address)
+		goto good_area;
+	if (!(vma->vm_flags & VM_GROWSDOWN))
+		goto bad_area;
+	if (expand_stack(vma, address))
+		goto bad_area;
+
+	/* Ok, we have a good vm_area for this memory access, so
+	 * we can handle it..
+	 */
+
+good_area:
+	info.si_code = SEGV_ACCERR;
+
+	if (is_write) {
+		if (!(vma->vm_flags & VM_WRITE))
+			goto bad_area;
+		flags |= FAULT_FLAG_WRITE;
+	} else if (is_exec) {
+		if (!(vma->vm_flags & VM_EXEC))
+			goto bad_area;
+	} else	/* Allow read even from write-only pages. */
+		if (!(vma->vm_flags & (VM_READ | VM_WRITE)))
+			goto bad_area;
+
+	/* If for any reason at all we couldn't handle the fault,
+	 * make sure we exit gracefully rather than endlessly redo
+	 * the fault.
+	 */
+	fault = handle_mm_fault(mm, vma, address, flags);
+
+	if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
+		return;
+
+	if (unlikely(fault & VM_FAULT_ERROR)) {
+		if (fault & VM_FAULT_OOM)
+			goto out_of_memory;
+		else if (fault & VM_FAULT_SIGSEGV)
+			goto bad_area;
+		else if (fault & VM_FAULT_SIGBUS)
+			goto do_sigbus;
+		BUG();
+	}
+	if (flags & FAULT_FLAG_ALLOW_RETRY) {
+		if (fault & VM_FAULT_MAJOR)
+			current->maj_flt++;
+		else
+			current->min_flt++;
+		if (fault & VM_FAULT_RETRY) {
+			flags &= ~FAULT_FLAG_ALLOW_RETRY;
+			flags |= FAULT_FLAG_TRIED;
+
+			 /* No need to up_read(&mm->mmap_sem) as we would
+			 * have already released it in __lock_page_or_retry
+			 * in mm/filemap.c.
+			 */
+
+			goto retry;
+		}
+	}
+
+	up_read(&mm->mmap_sem);
+	return;
+
+	/* Something tried to access memory that isn't in our memory map..
+	 * Fix it, but check if it's kernel or user first..
+	 */
+bad_area:
+	up_read(&mm->mmap_sem);
+	if (user_mode(regs)) {
+		current->thread.bad_vaddr = address;
+		current->thread.error_code = is_write;
+		info.si_signo = SIGSEGV;
+		info.si_errno = 0;
+		/* info.si_code has been set above */
+		info.si_addr = (void *) address;
+		force_sig_info(SIGSEGV, &info, current);
+		return;
+	}
+	bad_page_fault(regs, address, SIGSEGV);
+	return;
+
+
+	/* We ran out of memory, or some other thing happened to us that made
+	 * us unable to handle the page fault gracefully.
+	 */
+out_of_memory:
+	up_read(&mm->mmap_sem);
+	if (!user_mode(regs))
+		bad_page_fault(regs, address, SIGKILL);
+	else
+		pagefault_out_of_memory();
+	return;
+
+do_sigbus:
+	up_read(&mm->mmap_sem);
+
+	/* Send a sigbus, regardless of whether we were in kernel
+	 * or user mode.
+	 */
+	current->thread.bad_vaddr = address;
+	info.si_code = SIGBUS;
+	info.si_errno = 0;
+	info.si_code = BUS_ADRERR;
+	info.si_addr = (void *) address;
+	force_sig_info(SIGBUS, &info, current);
+
+	/* Kernel mode? Handle exceptions or die */
+	if (!user_mode(regs))
+		bad_page_fault(regs, address, SIGBUS);
+	return;
+
+vmalloc_fault:
+	{
+		/* Synchronize this task's top level page-table
+		 * with the 'reference' page table.
+		 */
+		struct mm_struct *act_mm = current->active_mm;
+		int index = pgd_index(address);
+		pgd_t *pgd, *pgd_k;
+		pmd_t *pmd, *pmd_k;
+		pte_t *pte_k;
+
+		if (act_mm == NULL)
+			goto bad_page_fault;
+
+		pgd = act_mm->pgd + index;
+		pgd_k = init_mm.pgd + index;
+
+		if (!pgd_present(*pgd_k))
+			goto bad_page_fault;
+
+		pgd_val(*pgd) = pgd_val(*pgd_k);
+
+		pmd = pmd_offset(pgd, address);
+		pmd_k = pmd_offset(pgd_k, address);
+		if (!pmd_present(*pmd) || !pmd_present(*pmd_k))
+			goto bad_page_fault;
+
+		pmd_val(*pmd) = pmd_val(*pmd_k);
+		pte_k = pte_offset_kernel(pmd_k, address);
+
+		if (!pte_present(*pte_k))
+			goto bad_page_fault;
+		return;
+	}
+bad_page_fault:
+	bad_page_fault(regs, address, SIGKILL);
+	return;
+}
+
+
+void
+bad_page_fault(struct pt_regs *regs, unsigned long address, int sig)
+{
+	extern void die(const char*, struct pt_regs*, long);
+	const struct exception_table_entry *entry;
+
+	/* Are we prepared to handle this kernel fault?  */
+	if ((entry = search_exception_tables(regs->pc)) != NULL) {
+#ifdef DEBUG_PAGE_FAULT
+		printk(KERN_DEBUG "%s: Exception at pc=%#010lx (%lx)\n",
+				current->comm, regs->pc, entry->fixup);
+#endif
+		current->thread.bad_uaddr = address;
+		regs->pc = entry->fixup;
+		return;
+	}
+
+	/* Oops. The kernel tried to access some bad page. We'll have to
+	 * terminate things with extreme prejudice.
+	 */
+	printk(KERN_ALERT "Unable to handle kernel paging request at virtual "
+	       "address %08lx\n pc = %08lx, ra = %08lx\n",
+	       address, regs->pc, regs->areg[0]);
+	die("Oops", regs, sig);
+	do_exit(sig);
+}
diff --git a/kernel/arch/xtensa/mm/highmem.c b/kernel/arch/xtensa/mm/highmem.c
new file mode 100644
index 000000000..184ceadcc
--- /dev/null
+++ b/kernel/arch/xtensa/mm/highmem.c
@@ -0,0 +1,95 @@
+/*
+ * High memory support for Xtensa architecture
+ *
+ * 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) 2014 Cadence Design Systems Inc.
+ */
+
+#include <linux/export.h>
+#include <linux/highmem.h>
+#include <asm/tlbflush.h>
+
+static pte_t *kmap_pte;
+
+#if DCACHE_WAY_SIZE > PAGE_SIZE
+unsigned int last_pkmap_nr_arr[DCACHE_N_COLORS];
+wait_queue_head_t pkmap_map_wait_arr[DCACHE_N_COLORS];
+
+static void __init kmap_waitqueues_init(void)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(pkmap_map_wait_arr); ++i)
+		init_waitqueue_head(pkmap_map_wait_arr + i);
+}
+#else
+static inline void kmap_waitqueues_init(void)
+{
+}
+#endif
+
+static inline enum fixed_addresses kmap_idx(int type, unsigned long color)
+{
+	return (type + KM_TYPE_NR * smp_processor_id()) * DCACHE_N_COLORS +
+		color;
+}
+
+void *kmap_atomic(struct page *page)
+{
+	enum fixed_addresses idx;
+	unsigned long vaddr;
+
+	preempt_disable();
+	pagefault_disable();
+	if (!PageHighMem(page))
+		return page_address(page);
+
+	idx = kmap_idx(kmap_atomic_idx_push(),
+		       DCACHE_ALIAS(page_to_phys(page)));
+	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+#ifdef CONFIG_DEBUG_HIGHMEM
+	BUG_ON(!pte_none(*(kmap_pte + idx)));
+#endif
+	set_pte(kmap_pte + idx, mk_pte(page, PAGE_KERNEL_EXEC));
+
+	return (void *)vaddr;
+}
+EXPORT_SYMBOL(kmap_atomic);
+
+void __kunmap_atomic(void *kvaddr)
+{
+	if (kvaddr >= (void *)FIXADDR_START &&
+	    kvaddr < (void *)FIXADDR_TOP) {
+		int idx = kmap_idx(kmap_atomic_idx(),
+				   DCACHE_ALIAS((unsigned long)kvaddr));
+
+		/*
+		 * Force other mappings to Oops if they'll try to access this
+		 * pte without first remap it.  Keeping stale mappings around
+		 * is a bad idea also, in case the page changes cacheability
+		 * attributes or becomes a protected page in a hypervisor.
+		 */
+		pte_clear(&init_mm, kvaddr, kmap_pte + idx);
+		local_flush_tlb_kernel_range((unsigned long)kvaddr,
+					     (unsigned long)kvaddr + PAGE_SIZE);
+
+		kmap_atomic_idx_pop();
+	}
+
+	pagefault_enable();
+	preempt_enable();
+}
+EXPORT_SYMBOL(__kunmap_atomic);
+
+void __init kmap_init(void)
+{
+	unsigned long kmap_vstart;
+
+	/* cache the first kmap pte */
+	kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
+	kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
+	kmap_waitqueues_init();
+}
diff --git a/kernel/arch/xtensa/mm/init.c b/kernel/arch/xtensa/mm/init.c
new file mode 100644
index 000000000..9a9a5935b
--- /dev/null
+++ b/kernel/arch/xtensa/mm/init.c
@@ -0,0 +1,430 @@
+/*
+ * arch/xtensa/mm/init.c
+ *
+ * Derived from MIPS, PPC.
+ *
+ * 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 - 2005 Tensilica Inc.
+ * Copyright (C) 2014 Cadence Design Systems Inc.
+ *
+ * Chris Zankel	<chris@zankel.net>
+ * Joe Taylor	<joe@tensilica.com, joetylr@yahoo.com>
+ * Marc Gauthier
+ * Kevin Chea
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/bootmem.h>
+#include <linux/gfp.h>
+#include <linux/highmem.h>
+#include <linux/swap.h>
+#include <linux/mman.h>
+#include <linux/nodemask.h>
+#include <linux/mm.h>
+
+#include <asm/bootparam.h>
+#include <asm/page.h>
+#include <asm/sections.h>
+#include <asm/sysmem.h>
+
+struct sysmem_info sysmem __initdata;
+
+static void __init sysmem_dump(void)
+{
+	unsigned i;
+
+	pr_debug("Sysmem:\n");
+	for (i = 0; i < sysmem.nr_banks; ++i)
+		pr_debug("  0x%08lx - 0x%08lx (%ldK)\n",
+			 sysmem.bank[i].start, sysmem.bank[i].end,
+			 (sysmem.bank[i].end - sysmem.bank[i].start) >> 10);
+}
+
+/*
+ * Find bank with maximal .start such that bank.start <= start
+ */
+static inline struct meminfo * __init find_bank(unsigned long start)
+{
+	unsigned i;
+	struct meminfo *it = NULL;
+
+	for (i = 0; i < sysmem.nr_banks; ++i)
+		if (sysmem.bank[i].start <= start)
+			it = sysmem.bank + i;
+		else
+			break;
+	return it;
+}
+
+/*
+ * Move all memory banks starting at 'from' to a new place at 'to',
+ * adjust nr_banks accordingly.
+ * Both 'from' and 'to' must be inside the sysmem.bank.
+ *
+ * Returns: 0 (success), -ENOMEM (not enough space in the sysmem.bank).
+ */
+static int __init move_banks(struct meminfo *to, struct meminfo *from)
+{
+	unsigned n = sysmem.nr_banks - (from - sysmem.bank);
+
+	if (to > from && to - from + sysmem.nr_banks > SYSMEM_BANKS_MAX)
+		return -ENOMEM;
+	if (to != from)
+		memmove(to, from, n * sizeof(struct meminfo));
+	sysmem.nr_banks += to - from;
+	return 0;
+}
+
+/*
+ * Add new bank to sysmem. Resulting sysmem is the union of bytes of the
+ * original sysmem and the new bank.
+ *
+ * Returns: 0 (success), < 0 (error)
+ */
+int __init add_sysmem_bank(unsigned long start, unsigned long end)
+{
+	unsigned i;
+	struct meminfo *it = NULL;
+	unsigned long sz;
+	unsigned long bank_sz = 0;
+
+	if (start == end ||
+	    (start < end) != (PAGE_ALIGN(start) < (end & PAGE_MASK))) {
+		pr_warn("Ignoring small memory bank 0x%08lx size: %ld bytes\n",
+			start, end - start);
+		return -EINVAL;
+	}
+
+	start = PAGE_ALIGN(start);
+	end &= PAGE_MASK;
+	sz = end - start;
+
+	it = find_bank(start);
+
+	if (it)
+		bank_sz = it->end - it->start;
+
+	if (it && bank_sz >= start - it->start) {
+		if (end - it->start > bank_sz)
+			it->end = end;
+		else
+			return 0;
+	} else {
+		if (!it)
+			it = sysmem.bank;
+		else
+			++it;
+
+		if (it - sysmem.bank < sysmem.nr_banks &&
+		    it->start - start <= sz) {
+			it->start = start;
+			if (it->end - it->start < sz)
+				it->end = end;
+			else
+				return 0;
+		} else {
+			if (move_banks(it + 1, it) < 0) {
+				pr_warn("Ignoring memory bank 0x%08lx size %ld bytes\n",
+					start, end - start);
+				return -EINVAL;
+			}
+			it->start = start;
+			it->end = end;
+			return 0;
+		}
+	}
+	sz = it->end - it->start;
+	for (i = it + 1 - sysmem.bank; i < sysmem.nr_banks; ++i)
+		if (sysmem.bank[i].start - it->start <= sz) {
+			if (sz < sysmem.bank[i].end - it->start)
+				it->end = sysmem.bank[i].end;
+		} else {
+			break;
+		}
+
+	move_banks(it + 1, sysmem.bank + i);
+	return 0;
+}
+
+/*
+ * mem_reserve(start, end, must_exist)
+ *
+ * Reserve some memory from the memory pool.
+ * If must_exist is set and a part of the region being reserved does not exist
+ * memory map is not altered.
+ *
+ * Parameters:
+ *  start	Start of region,
+ *  end		End of region,
+ *  must_exist	Must exist in memory pool.
+ *
+ * Returns:
+ *  0 (success)
+ *  < 0 (error)
+ */
+
+int __init mem_reserve(unsigned long start, unsigned long end, int must_exist)
+{
+	struct meminfo *it;
+	struct meminfo *rm = NULL;
+	unsigned long sz;
+	unsigned long bank_sz = 0;
+
+	start = start & PAGE_MASK;
+	end = PAGE_ALIGN(end);
+	sz = end - start;
+	if (!sz)
+		return -EINVAL;
+
+	it = find_bank(start);
+
+	if (it)
+		bank_sz = it->end - it->start;
+
+	if ((!it || end - it->start > bank_sz) && must_exist) {
+		pr_warn("mem_reserve: [0x%0lx, 0x%0lx) not in any region!\n",
+			start, end);
+		return -EINVAL;
+	}
+
+	if (it && start - it->start <= bank_sz) {
+		if (start == it->start) {
+			if (end - it->start < bank_sz) {
+				it->start = end;
+				return 0;
+			} else {
+				rm = it;
+			}
+		} else {
+			it->end = start;
+			if (end - it->start < bank_sz)
+				return add_sysmem_bank(end,
+						       it->start + bank_sz);
+			++it;
+		}
+	}
+
+	if (!it)
+		it = sysmem.bank;
+
+	for (; it < sysmem.bank + sysmem.nr_banks; ++it) {
+		if (it->end - start <= sz) {
+			if (!rm)
+				rm = it;
+		} else {
+			if (it->start - start < sz)
+				it->start = end;
+			break;
+		}
+	}
+
+	if (rm)
+		move_banks(rm, it);
+
+	return 0;
+}
+
+
+/*
+ * Initialize the bootmem system and give it all low memory we have available.
+ */
+
+void __init bootmem_init(void)
+{
+	unsigned long pfn;
+	unsigned long bootmap_start, bootmap_size;
+	int i;
+
+	/* Reserve all memory below PLATFORM_DEFAULT_MEM_START, as memory
+	 * accounting doesn't work for pages below that address.
+	 *
+	 * If PLATFORM_DEFAULT_MEM_START is zero reserve page at address 0:
+	 * successfull allocations should never return NULL.
+	 */
+	if (PLATFORM_DEFAULT_MEM_START)
+		mem_reserve(0, PLATFORM_DEFAULT_MEM_START, 0);
+	else
+		mem_reserve(0, 1, 0);
+
+	sysmem_dump();
+	max_low_pfn = max_pfn = 0;
+	min_low_pfn = ~0;
+
+	for (i=0; i < sysmem.nr_banks; i++) {
+		pfn = PAGE_ALIGN(sysmem.bank[i].start) >> PAGE_SHIFT;
+		if (pfn < min_low_pfn)
+			min_low_pfn = pfn;
+		pfn = PAGE_ALIGN(sysmem.bank[i].end - 1) >> PAGE_SHIFT;
+		if (pfn > max_pfn)
+			max_pfn = pfn;
+	}
+
+	if (min_low_pfn > max_pfn)
+		panic("No memory found!\n");
+
+	max_low_pfn = max_pfn < MAX_MEM_PFN >> PAGE_SHIFT ?
+		max_pfn : MAX_MEM_PFN >> PAGE_SHIFT;
+
+	/* Find an area to use for the bootmem bitmap. */
+
+	bootmap_size = bootmem_bootmap_pages(max_low_pfn - min_low_pfn);
+	bootmap_size <<= PAGE_SHIFT;
+	bootmap_start = ~0;
+
+	for (i=0; i<sysmem.nr_banks; i++)
+		if (sysmem.bank[i].end - sysmem.bank[i].start >= bootmap_size) {
+			bootmap_start = sysmem.bank[i].start;
+			break;
+		}
+
+	if (bootmap_start == ~0UL)
+		panic("Cannot find %ld bytes for bootmap\n", bootmap_size);
+
+	/* Reserve the bootmem bitmap area */
+
+	mem_reserve(bootmap_start, bootmap_start + bootmap_size, 1);
+	bootmap_size = init_bootmem_node(NODE_DATA(0),
+					 bootmap_start >> PAGE_SHIFT,
+					 min_low_pfn,
+					 max_low_pfn);
+
+	/* Add all remaining memory pieces into the bootmem map */
+
+	for (i = 0; i < sysmem.nr_banks; i++) {
+		if (sysmem.bank[i].start >> PAGE_SHIFT < max_low_pfn) {
+			unsigned long end = min(max_low_pfn << PAGE_SHIFT,
+						sysmem.bank[i].end);
+			free_bootmem(sysmem.bank[i].start,
+				     end - sysmem.bank[i].start);
+		}
+	}
+
+}
+
+
+void __init zones_init(void)
+{
+	/* All pages are DMA-able, so we put them all in the DMA zone. */
+	unsigned long zones_size[MAX_NR_ZONES] = {
+		[ZONE_DMA] = max_low_pfn - ARCH_PFN_OFFSET,
+#ifdef CONFIG_HIGHMEM
+		[ZONE_HIGHMEM] = max_pfn - max_low_pfn,
+#endif
+	};
+	free_area_init_node(0, zones_size, ARCH_PFN_OFFSET, NULL);
+}
+
+/*
+ * Initialize memory pages.
+ */
+
+void __init mem_init(void)
+{
+#ifdef CONFIG_HIGHMEM
+	unsigned long tmp;
+
+	reset_all_zones_managed_pages();
+	for (tmp = max_low_pfn; tmp < max_pfn; tmp++)
+		free_highmem_page(pfn_to_page(tmp));
+#endif
+
+	max_mapnr = max_pfn - ARCH_PFN_OFFSET;
+	high_memory = (void *)__va(max_low_pfn << PAGE_SHIFT);
+
+	free_all_bootmem();
+
+	mem_init_print_info(NULL);
+	pr_info("virtual kernel memory layout:\n"
+#ifdef CONFIG_HIGHMEM
+		"    pkmap   : 0x%08lx - 0x%08lx  (%5lu kB)\n"
+		"    fixmap  : 0x%08lx - 0x%08lx  (%5lu kB)\n"
+#endif
+#ifdef CONFIG_MMU
+		"    vmalloc : 0x%08x - 0x%08x  (%5u MB)\n"
+#endif
+		"    lowmem  : 0x%08lx - 0x%08lx  (%5lu MB)\n",
+#ifdef CONFIG_HIGHMEM
+		PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE,
+		(LAST_PKMAP*PAGE_SIZE) >> 10,
+		FIXADDR_START, FIXADDR_TOP,
+		(FIXADDR_TOP - FIXADDR_START) >> 10,
+#endif
+#ifdef CONFIG_MMU
+		VMALLOC_START, VMALLOC_END,
+		(VMALLOC_END - VMALLOC_START) >> 20,
+		PAGE_OFFSET, PAGE_OFFSET +
+		(max_low_pfn - min_low_pfn) * PAGE_SIZE,
+#else
+		min_low_pfn * PAGE_SIZE, max_low_pfn * PAGE_SIZE,
+#endif
+		((max_low_pfn - min_low_pfn) * PAGE_SIZE) >> 20);
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+extern int initrd_is_mapped;
+
+void free_initrd_mem(unsigned long start, unsigned long end)
+{
+	if (initrd_is_mapped)
+		free_reserved_area((void *)start, (void *)end, -1, "initrd");
+}
+#endif
+
+void free_initmem(void)
+{
+	free_initmem_default(-1);
+}
+
+static void __init parse_memmap_one(char *p)
+{
+	char *oldp;
+	unsigned long start_at, mem_size;
+
+	if (!p)
+		return;
+
+	oldp = p;
+	mem_size = memparse(p, &p);
+	if (p == oldp)
+		return;
+
+	switch (*p) {
+	case '@':
+		start_at = memparse(p + 1, &p);
+		add_sysmem_bank(start_at, start_at + mem_size);
+		break;
+
+	case '$':
+		start_at = memparse(p + 1, &p);
+		mem_reserve(start_at, start_at + mem_size, 0);
+		break;
+
+	case 0:
+		mem_reserve(mem_size, 0, 0);
+		break;
+
+	default:
+		pr_warn("Unrecognized memmap syntax: %s\n", p);
+		break;
+	}
+}
+
+static int __init parse_memmap_opt(char *str)
+{
+	while (str) {
+		char *k = strchr(str, ',');
+
+		if (k)
+			*k++ = 0;
+
+		parse_memmap_one(str);
+		str = k;
+	}
+
+	return 0;
+}
+early_param("memmap", parse_memmap_opt);
diff --git a/kernel/arch/xtensa/mm/misc.S b/kernel/arch/xtensa/mm/misc.S
new file mode 100644
index 000000000..11a01c3e9
--- /dev/null
+++ b/kernel/arch/xtensa/mm/misc.S
@@ -0,0 +1,484 @@
+/*
+ * arch/xtensa/mm/misc.S
+ *
+ * Miscellaneous assembly functions.
+ *
+ * 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 - 2007 Tensilica Inc.
+ *
+ * Chris Zankel	<chris@zankel.net>
+ */
+
+
+#include <linux/linkage.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/asmmacro.h>
+#include <asm/cacheasm.h>
+#include <asm/tlbflush.h>
+
+
+/*
+ * clear_page and clear_user_page are the same for non-cache-aliased configs.
+ *
+ * clear_page (unsigned long page)
+ *                    a2
+ */
+
+ENTRY(clear_page)
+
+	entry	a1, 16
+
+	movi	a3, 0
+	__loopi	a2, a7, PAGE_SIZE, 32
+	s32i	a3, a2, 0
+	s32i	a3, a2, 4
+	s32i	a3, a2, 8
+	s32i	a3, a2, 12
+	s32i	a3, a2, 16
+	s32i	a3, a2, 20
+	s32i	a3, a2, 24
+	s32i	a3, a2, 28
+	__endla	a2, a7, 32
+
+	retw
+
+ENDPROC(clear_page)
+
+/*
+ * copy_page and copy_user_page are the same for non-cache-aliased configs.
+ *
+ * copy_page (void *to, void *from)
+ *               a2          a3
+ */
+
+ENTRY(copy_page)
+
+	entry	a1, 16
+
+	__loopi a2, a4, PAGE_SIZE, 32
+
+	l32i    a8, a3, 0
+	l32i    a9, a3, 4
+	s32i    a8, a2, 0
+	s32i    a9, a2, 4
+
+	l32i    a8, a3, 8
+	l32i    a9, a3, 12
+	s32i    a8, a2, 8
+	s32i    a9, a2, 12
+
+	l32i    a8, a3, 16
+	l32i    a9, a3, 20
+	s32i    a8, a2, 16
+	s32i    a9, a2, 20
+
+	l32i    a8, a3, 24
+	l32i    a9, a3, 28
+	s32i    a8, a2, 24
+	s32i    a9, a2, 28
+
+	addi    a2, a2, 32
+	addi    a3, a3, 32
+
+	__endl  a2, a4
+
+	retw
+
+ENDPROC(copy_page)
+
+#ifdef CONFIG_MMU
+/*
+ * If we have to deal with cache aliasing, we use temporary memory mappings
+ * to ensure that the source and destination pages have the same color as
+ * the virtual address. We use way 0 and 1 for temporary mappings in such cases.
+ *
+ * The temporary DTLB entries shouldn't be flushed by interrupts, but are
+ * flushed by preemptive task switches. Special code in the 
+ * fast_second_level_miss handler re-established the temporary mapping. 
+ * It requires that the PPNs for the destination and source addresses are
+ * in a6, and a7, respectively.
+ */
+
+/* TLB miss exceptions are treated special in the following region */
+
+ENTRY(__tlbtemp_mapping_start)
+
+#if (DCACHE_WAY_SIZE > PAGE_SIZE)
+
+/*
+ * clear_page_alias(void *addr, unsigned long paddr)
+ *                     a2              a3
+ */
+
+ENTRY(clear_page_alias)
+
+	entry	a1, 32
+
+	/* Skip setting up a temporary DTLB if not aliased low page. */
+
+	movi	a5, PAGE_OFFSET
+	movi	a6, 0
+	beqz	a3, 1f
+
+	/* Setup a temporary DTLB for the addr. */
+
+	addi	a6, a3, (PAGE_KERNEL | _PAGE_HW_WRITE)
+	mov	a4, a2
+	wdtlb	a6, a2
+	dsync
+
+1:	movi	a3, 0
+	__loopi	a2, a7, PAGE_SIZE, 32
+	s32i	a3, a2, 0
+	s32i	a3, a2, 4
+	s32i	a3, a2, 8
+	s32i	a3, a2, 12
+	s32i	a3, a2, 16
+	s32i	a3, a2, 20
+	s32i	a3, a2, 24
+	s32i	a3, a2, 28
+	__endla	a2, a7, 32
+
+	bnez	a6, 1f
+	retw
+
+	/* We need to invalidate the temporary idtlb entry, if any. */
+
+1:	idtlb	a4
+	dsync
+
+	retw
+
+ENDPROC(clear_page_alias)
+
+/*
+ * copy_page_alias(void *to, void *from,
+ *			a2	  a3
+ *                 unsigned long to_paddr, unsigned long from_paddr)
+ *	        		 a4			 a5
+ */
+
+ENTRY(copy_page_alias)
+
+	entry	a1, 32
+
+	/* Skip setting up a temporary DTLB for destination if not aliased. */
+
+	movi	a6, 0
+	movi	a7, 0
+	beqz	a4, 1f
+
+	/* Setup a temporary DTLB for destination. */
+
+	addi	a6, a4, (PAGE_KERNEL | _PAGE_HW_WRITE)
+	wdtlb	a6, a2
+	dsync
+
+	/* Skip setting up a temporary DTLB for source if not aliased. */
+
+1:	beqz	a5, 1f
+
+	/* Setup a temporary DTLB for source. */
+
+	addi	a7, a5, PAGE_KERNEL
+	addi	a8, a3, 1				# way1
+
+	wdtlb	a7, a8
+	dsync
+
+1:	__loopi a2, a4, PAGE_SIZE, 32
+
+	l32i    a8, a3, 0
+	l32i    a9, a3, 4
+	s32i    a8, a2, 0
+	s32i    a9, a2, 4
+
+	l32i    a8, a3, 8
+	l32i    a9, a3, 12
+	s32i    a8, a2, 8
+	s32i    a9, a2, 12
+
+	l32i    a8, a3, 16
+	l32i    a9, a3, 20
+	s32i    a8, a2, 16
+	s32i    a9, a2, 20
+
+	l32i    a8, a3, 24
+	l32i    a9, a3, 28
+	s32i    a8, a2, 24
+	s32i    a9, a2, 28
+
+	addi    a2, a2, 32
+	addi    a3, a3, 32
+
+	__endl  a2, a4
+
+	/* We need to invalidate any temporary mapping! */
+
+	bnez	a6, 1f
+	bnez	a7, 2f
+	retw
+
+1:	addi	a2, a2, -PAGE_SIZE
+	idtlb	a2
+	dsync
+	bnez	a7, 2f
+	retw
+
+2:	addi	a3, a3, -PAGE_SIZE+1
+	idtlb	a3
+	dsync
+
+	retw
+
+ENDPROC(copy_page_alias)
+
+#endif
+
+#if (DCACHE_WAY_SIZE > PAGE_SIZE)
+
+/*
+ * void __flush_invalidate_dcache_page_alias (addr, phys)
+ *                                             a2    a3
+ */
+
+ENTRY(__flush_invalidate_dcache_page_alias)
+
+	entry	sp, 16
+
+	movi	a7, 0			# required for exception handler
+	addi	a6, a3, (PAGE_KERNEL | _PAGE_HW_WRITE)
+	mov	a4, a2
+	wdtlb	a6, a2
+	dsync
+
+	___flush_invalidate_dcache_page a2 a3
+
+	idtlb	a4
+	dsync
+
+	retw
+
+ENDPROC(__flush_invalidate_dcache_page_alias)
+
+/*
+ * void __invalidate_dcache_page_alias (addr, phys)
+ *                                       a2    a3
+ */
+
+ENTRY(__invalidate_dcache_page_alias)
+
+	entry	sp, 16
+
+	movi	a7, 0			# required for exception handler
+	addi	a6, a3, (PAGE_KERNEL | _PAGE_HW_WRITE)
+	mov	a4, a2
+	wdtlb	a6, a2
+	dsync
+
+	___invalidate_dcache_page a2 a3
+
+	idtlb	a4
+	dsync
+
+	retw
+
+ENDPROC(__invalidate_dcache_page_alias)
+#endif
+
+ENTRY(__tlbtemp_mapping_itlb)
+
+#if (ICACHE_WAY_SIZE > PAGE_SIZE)
+	
+ENTRY(__invalidate_icache_page_alias)
+
+	entry	sp, 16
+
+	addi	a6, a3, (PAGE_KERNEL_EXEC | _PAGE_HW_WRITE)
+	mov	a4, a2
+	witlb	a6, a2
+	isync
+
+	___invalidate_icache_page a2 a3
+
+	iitlb	a4
+	isync
+	retw
+
+ENDPROC(__invalidate_icache_page_alias)
+
+#endif
+
+/* End of special treatment in tlb miss exception */
+
+ENTRY(__tlbtemp_mapping_end)
+
+#endif /* CONFIG_MMU
+
+/*
+ * void __invalidate_icache_page(ulong start)
+ */
+
+ENTRY(__invalidate_icache_page)
+
+	entry	sp, 16
+
+	___invalidate_icache_page a2 a3
+	isync
+
+	retw
+
+ENDPROC(__invalidate_icache_page)
+
+/*
+ * void __invalidate_dcache_page(ulong start)
+ */
+
+ENTRY(__invalidate_dcache_page)
+
+	entry	sp, 16
+
+	___invalidate_dcache_page a2 a3
+	dsync
+
+	retw
+
+ENDPROC(__invalidate_dcache_page)
+
+/*
+ * void __flush_invalidate_dcache_page(ulong start)
+ */
+
+ENTRY(__flush_invalidate_dcache_page)
+
+	entry	sp, 16
+
+	___flush_invalidate_dcache_page a2 a3
+
+	dsync
+	retw
+
+ENDPROC(__flush_invalidate_dcache_page)
+
+/*
+ * void __flush_dcache_page(ulong start)
+ */
+
+ENTRY(__flush_dcache_page)
+
+	entry	sp, 16
+
+	___flush_dcache_page a2 a3
+
+	dsync
+	retw
+
+ENDPROC(__flush_dcache_page)
+
+/*
+ * void __invalidate_icache_range(ulong start, ulong size)
+ */
+
+ENTRY(__invalidate_icache_range)
+
+	entry	sp, 16
+
+	___invalidate_icache_range a2 a3 a4
+	isync
+
+	retw
+
+ENDPROC(__invalidate_icache_range)
+
+/*
+ * void __flush_invalidate_dcache_range(ulong start, ulong size)
+ */
+
+ENTRY(__flush_invalidate_dcache_range)
+
+	entry	sp, 16
+
+	___flush_invalidate_dcache_range a2 a3 a4
+	dsync
+
+	retw
+
+ENDPROC(__flush_invalidate_dcache_range)
+
+/*
+ * void _flush_dcache_range(ulong start, ulong size)
+ */
+
+ENTRY(__flush_dcache_range)
+
+	entry	sp, 16
+
+	___flush_dcache_range a2 a3 a4
+	dsync
+
+	retw
+
+ENDPROC(__flush_dcache_range)
+
+/*
+ * void _invalidate_dcache_range(ulong start, ulong size)
+ */
+
+ENTRY(__invalidate_dcache_range)
+
+	entry	sp, 16
+
+	___invalidate_dcache_range a2 a3 a4
+
+	retw
+
+ENDPROC(__invalidate_dcache_range)
+
+/*
+ * void _invalidate_icache_all(void)
+ */
+
+ENTRY(__invalidate_icache_all)
+
+	entry	sp, 16
+
+	___invalidate_icache_all a2 a3
+	isync
+
+	retw
+
+ENDPROC(__invalidate_icache_all)
+
+/*
+ * void _flush_invalidate_dcache_all(void)
+ */
+
+ENTRY(__flush_invalidate_dcache_all)
+
+	entry	sp, 16
+
+	___flush_invalidate_dcache_all a2 a3
+	dsync
+
+	retw
+
+ENDPROC(__flush_invalidate_dcache_all)
+
+/*
+ * void _invalidate_dcache_all(void)
+ */
+
+ENTRY(__invalidate_dcache_all)
+
+	entry	sp, 16
+
+	___invalidate_dcache_all a2 a3
+	dsync
+
+	retw
+
+ENDPROC(__invalidate_dcache_all)
diff --git a/kernel/arch/xtensa/mm/mmu.c b/kernel/arch/xtensa/mm/mmu.c
new file mode 100644
index 000000000..abe4513eb
--- /dev/null
+++ b/kernel/arch/xtensa/mm/mmu.c
@@ -0,0 +1,110 @@
+/*
+ * xtensa mmu stuff
+ *
+ * Extracted from init.c
+ */
+#include <linux/bootmem.h>
+#include <linux/percpu.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/cache.h>
+
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
+#include <asm/page.h>
+#include <asm/initialize_mmu.h>
+#include <asm/io.h>
+
+#if defined(CONFIG_HIGHMEM)
+static void * __init init_pmd(unsigned long vaddr, unsigned long n_pages)
+{
+	pgd_t *pgd = pgd_offset_k(vaddr);
+	pmd_t *pmd = pmd_offset(pgd, vaddr);
+	pte_t *pte;
+	unsigned long i;
+
+	n_pages = ALIGN(n_pages, PTRS_PER_PTE);
+
+	pr_debug("%s: vaddr: 0x%08lx, n_pages: %ld\n",
+		 __func__, vaddr, n_pages);
+
+	pte = alloc_bootmem_low_pages(n_pages * sizeof(pte_t));
+
+	for (i = 0; i < n_pages; ++i)
+		pte_clear(NULL, 0, pte + i);
+
+	for (i = 0; i < n_pages; i += PTRS_PER_PTE, ++pmd) {
+		pte_t *cur_pte = pte + i;
+
+		BUG_ON(!pmd_none(*pmd));
+		set_pmd(pmd, __pmd(((unsigned long)cur_pte) & PAGE_MASK));
+		BUG_ON(cur_pte != pte_offset_kernel(pmd, 0));
+		pr_debug("%s: pmd: 0x%p, pte: 0x%p\n",
+			 __func__, pmd, cur_pte);
+	}
+	return pte;
+}
+
+static void __init fixedrange_init(void)
+{
+	init_pmd(__fix_to_virt(0), __end_of_fixed_addresses);
+}
+#endif
+
+void __init paging_init(void)
+{
+	memset(swapper_pg_dir, 0, PAGE_SIZE);
+#ifdef CONFIG_HIGHMEM
+	fixedrange_init();
+	pkmap_page_table = init_pmd(PKMAP_BASE, LAST_PKMAP);
+	kmap_init();
+#endif
+}
+
+/*
+ * Flush the mmu and reset associated register to default values.
+ */
+void init_mmu(void)
+{
+#if !(XCHAL_HAVE_PTP_MMU && XCHAL_HAVE_SPANNING_WAY)
+	/*
+	 * Writing zeros to the instruction and data TLBCFG special
+	 * registers ensure that valid values exist in the register.
+	 *
+	 * For existing PGSZID<w> fields, zero selects the first element
+	 * of the page-size array.  For nonexistent PGSZID<w> fields,
+	 * zero is the best value to write.  Also, when changing PGSZID<w>
+	 * fields, the corresponding TLB must be flushed.
+	 */
+	set_itlbcfg_register(0);
+	set_dtlbcfg_register(0);
+#endif
+#if XCHAL_HAVE_PTP_MMU && XCHAL_HAVE_SPANNING_WAY && defined(CONFIG_OF)
+	/*
+	 * Update the IO area mapping in case xtensa_kio_paddr has changed
+	 */
+	write_dtlb_entry(__pte(xtensa_kio_paddr + CA_WRITEBACK),
+			XCHAL_KIO_CACHED_VADDR + 6);
+	write_itlb_entry(__pte(xtensa_kio_paddr + CA_WRITEBACK),
+			XCHAL_KIO_CACHED_VADDR + 6);
+	write_dtlb_entry(__pte(xtensa_kio_paddr + CA_BYPASS),
+			XCHAL_KIO_BYPASS_VADDR + 6);
+	write_itlb_entry(__pte(xtensa_kio_paddr + CA_BYPASS),
+			XCHAL_KIO_BYPASS_VADDR + 6);
+#endif
+
+	local_flush_tlb_all();
+
+	/* Set rasid register to a known value. */
+
+	set_rasid_register(ASID_INSERT(ASID_USER_FIRST));
+
+	/* Set PTEVADDR special register to the start of the page
+	 * table, which is in kernel mappable space (ie. not
+	 * statically mapped).  This register's value is undefined on
+	 * reset.
+	 */
+	set_ptevaddr_register(PGTABLE_START);
+}
diff --git a/kernel/arch/xtensa/mm/tlb.c b/kernel/arch/xtensa/mm/tlb.c
new file mode 100644
index 000000000..5ece856c5
--- /dev/null
+++ b/kernel/arch/xtensa/mm/tlb.c
@@ -0,0 +1,278 @@
+/*
+ * arch/xtensa/mm/tlb.c
+ *
+ * Logic that manipulates the Xtensa MMU.  Derived from MIPS.
+ *
+ * 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 - 2003 Tensilica Inc.
+ *
+ * Joe Taylor
+ * Chris Zankel	<chris@zankel.net>
+ * Marc Gauthier
+ */
+
+#include <linux/mm.h>
+#include <asm/processor.h>
+#include <asm/mmu_context.h>
+#include <asm/tlbflush.h>
+#include <asm/cacheflush.h>
+
+
+static inline void __flush_itlb_all (void)
+{
+	int w, i;
+
+	for (w = 0; w < ITLB_ARF_WAYS; w++) {
+		for (i = 0; i < (1 << XCHAL_ITLB_ARF_ENTRIES_LOG2); i++) {
+			int e = w + (i << PAGE_SHIFT);
+			invalidate_itlb_entry_no_isync(e);
+		}
+	}
+	asm volatile ("isync\n");
+}
+
+static inline void __flush_dtlb_all (void)
+{
+	int w, i;
+
+	for (w = 0; w < DTLB_ARF_WAYS; w++) {
+		for (i = 0; i < (1 << XCHAL_DTLB_ARF_ENTRIES_LOG2); i++) {
+			int e = w + (i << PAGE_SHIFT);
+			invalidate_dtlb_entry_no_isync(e);
+		}
+	}
+	asm volatile ("isync\n");
+}
+
+
+void local_flush_tlb_all(void)
+{
+	__flush_itlb_all();
+	__flush_dtlb_all();
+}
+
+/* If mm is current, we simply assign the current task a new ASID, thus,
+ * invalidating all previous tlb entries. If mm is someone else's user mapping,
+ * wie invalidate the context, thus, when that user mapping is swapped in,
+ * a new context will be assigned to it.
+ */
+
+void local_flush_tlb_mm(struct mm_struct *mm)
+{
+	int cpu = smp_processor_id();
+
+	if (mm == current->active_mm) {
+		unsigned long flags;
+		local_irq_save(flags);
+		mm->context.asid[cpu] = NO_CONTEXT;
+		activate_context(mm, cpu);
+		local_irq_restore(flags);
+	} else {
+		mm->context.asid[cpu] = NO_CONTEXT;
+		mm->context.cpu = -1;
+	}
+}
+
+
+#define _ITLB_ENTRIES (ITLB_ARF_WAYS << XCHAL_ITLB_ARF_ENTRIES_LOG2)
+#define _DTLB_ENTRIES (DTLB_ARF_WAYS << XCHAL_DTLB_ARF_ENTRIES_LOG2)
+#if _ITLB_ENTRIES > _DTLB_ENTRIES
+# define _TLB_ENTRIES _ITLB_ENTRIES
+#else
+# define _TLB_ENTRIES _DTLB_ENTRIES
+#endif
+
+void local_flush_tlb_range(struct vm_area_struct *vma,
+		unsigned long start, unsigned long end)
+{
+	int cpu = smp_processor_id();
+	struct mm_struct *mm = vma->vm_mm;
+	unsigned long flags;
+
+	if (mm->context.asid[cpu] == NO_CONTEXT)
+		return;
+
+#if 0
+	printk("[tlbrange<%02lx,%08lx,%08lx>]\n",
+			(unsigned long)mm->context.asid[cpu], start, end);
+#endif
+	local_irq_save(flags);
+
+	if (end-start + (PAGE_SIZE-1) <= _TLB_ENTRIES << PAGE_SHIFT) {
+		int oldpid = get_rasid_register();
+
+		set_rasid_register(ASID_INSERT(mm->context.asid[cpu]));
+		start &= PAGE_MASK;
+		if (vma->vm_flags & VM_EXEC)
+			while(start < end) {
+				invalidate_itlb_mapping(start);
+				invalidate_dtlb_mapping(start);
+				start += PAGE_SIZE;
+			}
+		else
+			while(start < end) {
+				invalidate_dtlb_mapping(start);
+				start += PAGE_SIZE;
+			}
+
+		set_rasid_register(oldpid);
+	} else {
+		local_flush_tlb_mm(mm);
+	}
+	local_irq_restore(flags);
+}
+
+void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
+{
+	int cpu = smp_processor_id();
+	struct mm_struct* mm = vma->vm_mm;
+	unsigned long flags;
+	int oldpid;
+
+	if (mm->context.asid[cpu] == NO_CONTEXT)
+		return;
+
+	local_irq_save(flags);
+
+	oldpid = get_rasid_register();
+	set_rasid_register(ASID_INSERT(mm->context.asid[cpu]));
+
+	if (vma->vm_flags & VM_EXEC)
+		invalidate_itlb_mapping(page);
+	invalidate_dtlb_mapping(page);
+
+	set_rasid_register(oldpid);
+
+	local_irq_restore(flags);
+}
+
+void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
+{
+	if (end > start && start >= TASK_SIZE && end <= PAGE_OFFSET &&
+	    end - start < _TLB_ENTRIES << PAGE_SHIFT) {
+		start &= PAGE_MASK;
+		while (start < end) {
+			invalidate_itlb_mapping(start);
+			invalidate_dtlb_mapping(start);
+			start += PAGE_SIZE;
+		}
+	} else {
+		local_flush_tlb_all();
+	}
+}
+
+#ifdef CONFIG_DEBUG_TLB_SANITY
+
+static unsigned get_pte_for_vaddr(unsigned vaddr)
+{
+	struct task_struct *task = get_current();
+	struct mm_struct *mm = task->mm;
+	pgd_t *pgd;
+	pmd_t *pmd;
+	pte_t *pte;
+
+	if (!mm)
+		mm = task->active_mm;
+	pgd = pgd_offset(mm, vaddr);
+	if (pgd_none_or_clear_bad(pgd))
+		return 0;
+	pmd = pmd_offset(pgd, vaddr);
+	if (pmd_none_or_clear_bad(pmd))
+		return 0;
+	pte = pte_offset_map(pmd, vaddr);
+	if (!pte)
+		return 0;
+	return pte_val(*pte);
+}
+
+enum {
+	TLB_SUSPICIOUS	= 1,
+	TLB_INSANE	= 2,
+};
+
+static void tlb_insane(void)
+{
+	BUG_ON(1);
+}
+
+static void tlb_suspicious(void)
+{
+	WARN_ON(1);
+}
+
+/*
+ * Check that TLB entries with kernel ASID (1) have kernel VMA (>= TASK_SIZE),
+ * and TLB entries with user ASID (>=4) have VMA < TASK_SIZE.
+ *
+ * Check that valid TLB entries either have the same PA as the PTE, or PTE is
+ * marked as non-present. Non-present PTE and the page with non-zero refcount
+ * and zero mapcount is normal for batched TLB flush operation. Zero refcount
+ * means that the page was freed prematurely. Non-zero mapcount is unusual,
+ * but does not necessary means an error, thus marked as suspicious.
+ */
+static int check_tlb_entry(unsigned w, unsigned e, bool dtlb)
+{
+	unsigned tlbidx = w | (e << PAGE_SHIFT);
+	unsigned r0 = dtlb ?
+		read_dtlb_virtual(tlbidx) : read_itlb_virtual(tlbidx);
+	unsigned vpn = (r0 & PAGE_MASK) | (e << PAGE_SHIFT);
+	unsigned pte = get_pte_for_vaddr(vpn);
+	unsigned mm_asid = (get_rasid_register() >> 8) & ASID_MASK;
+	unsigned tlb_asid = r0 & ASID_MASK;
+	bool kernel = tlb_asid == 1;
+	int rc = 0;
+
+	if (tlb_asid > 0 && ((vpn < TASK_SIZE) == kernel)) {
+		pr_err("%cTLB: way: %u, entry: %u, VPN %08x in %s PTE\n",
+				dtlb ? 'D' : 'I', w, e, vpn,
+				kernel ? "kernel" : "user");
+		rc |= TLB_INSANE;
+	}
+
+	if (tlb_asid == mm_asid) {
+		unsigned r1 = dtlb ? read_dtlb_translation(tlbidx) :
+			read_itlb_translation(tlbidx);
+		if ((pte ^ r1) & PAGE_MASK) {
+			pr_err("%cTLB: way: %u, entry: %u, mapping: %08x->%08x, PTE: %08x\n",
+					dtlb ? 'D' : 'I', w, e, r0, r1, pte);
+			if (pte == 0 || !pte_present(__pte(pte))) {
+				struct page *p = pfn_to_page(r1 >> PAGE_SHIFT);
+				pr_err("page refcount: %d, mapcount: %d\n",
+						page_count(p),
+						page_mapcount(p));
+				if (!page_count(p))
+					rc |= TLB_INSANE;
+				else if (page_mapped(p))
+					rc |= TLB_SUSPICIOUS;
+			} else {
+				rc |= TLB_INSANE;
+			}
+		}
+	}
+	return rc;
+}
+
+void check_tlb_sanity(void)
+{
+	unsigned long flags;
+	unsigned w, e;
+	int bug = 0;
+
+	local_irq_save(flags);
+	for (w = 0; w < DTLB_ARF_WAYS; ++w)
+		for (e = 0; e < (1 << XCHAL_DTLB_ARF_ENTRIES_LOG2); ++e)
+			bug |= check_tlb_entry(w, e, true);
+	for (w = 0; w < ITLB_ARF_WAYS; ++w)
+		for (e = 0; e < (1 << XCHAL_ITLB_ARF_ENTRIES_LOG2); ++e)
+			bug |= check_tlb_entry(w, e, false);
+	if (bug & TLB_INSANE)
+		tlb_insane();
+	if (bug & TLB_SUSPICIOUS)
+		tlb_suspicious();
+	local_irq_restore(flags);
+}
+
+#endif /* CONFIG_DEBUG_TLB_SANITY */