v4.19.13 snapshot.
diff --git a/arch/nds32/mm/cacheflush.c b/arch/nds32/mm/cacheflush.c
new file mode 100644
index 0000000..2547036
--- /dev/null
+++ b/arch/nds32/mm/cacheflush.c
@@ -0,0 +1,348 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/module.h>
+#include <asm/cacheflush.h>
+#include <asm/proc-fns.h>
+#include <asm/shmparam.h>
+#include <asm/cache_info.h>
+
+extern struct cache_info L1_cache_info[2];
+
+void flush_icache_range(unsigned long start, unsigned long end)
+{
+	unsigned long line_size, flags;
+	line_size = L1_cache_info[DCACHE].line_size;
+	start = start & ~(line_size - 1);
+	end = (end + line_size - 1) & ~(line_size - 1);
+	local_irq_save(flags);
+	cpu_cache_wbinval_range(start, end, 1);
+	local_irq_restore(flags);
+}
+EXPORT_SYMBOL(flush_icache_range);
+
+void flush_icache_page(struct vm_area_struct *vma, struct page *page)
+{
+	unsigned long flags;
+	unsigned long kaddr;
+	local_irq_save(flags);
+	kaddr = (unsigned long)kmap_atomic(page);
+	cpu_cache_wbinval_page(kaddr, vma->vm_flags & VM_EXEC);
+	kunmap_atomic((void *)kaddr);
+	local_irq_restore(flags);
+}
+EXPORT_SYMBOL(flush_icache_page);
+
+void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
+	                     unsigned long addr, int len)
+{
+	unsigned long kaddr;
+	kaddr = (unsigned long)kmap_atomic(page) + (addr & ~PAGE_MASK);
+	flush_icache_range(kaddr, kaddr + len);
+	kunmap_atomic((void *)kaddr);
+}
+
+void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr,
+		      pte_t * pte)
+{
+	struct page *page;
+	unsigned long pfn = pte_pfn(*pte);
+	unsigned long flags;
+
+	if (!pfn_valid(pfn))
+		return;
+
+	if (vma->vm_mm == current->active_mm) {
+		local_irq_save(flags);
+		__nds32__mtsr_dsb(addr, NDS32_SR_TLB_VPN);
+		__nds32__tlbop_rwr(*pte);
+		__nds32__isb();
+		local_irq_restore(flags);
+	}
+	page = pfn_to_page(pfn);
+
+	if ((test_and_clear_bit(PG_dcache_dirty, &page->flags)) ||
+	    (vma->vm_flags & VM_EXEC)) {
+		unsigned long kaddr;
+		local_irq_save(flags);
+		kaddr = (unsigned long)kmap_atomic(page);
+		cpu_cache_wbinval_page(kaddr, vma->vm_flags & VM_EXEC);
+		kunmap_atomic((void *)kaddr);
+		local_irq_restore(flags);
+	}
+}
+#ifdef CONFIG_CPU_CACHE_ALIASING
+extern pte_t va_present(struct mm_struct *mm, unsigned long addr);
+
+static inline unsigned long aliasing(unsigned long addr, unsigned long page)
+{
+	return ((addr & PAGE_MASK) ^ page) & (SHMLBA - 1);
+}
+
+static inline unsigned long kremap0(unsigned long uaddr, unsigned long pa)
+{
+	unsigned long kaddr, pte;
+
+#define BASE_ADDR0 0xffffc000
+	kaddr = BASE_ADDR0 | (uaddr & L1_cache_info[DCACHE].aliasing_mask);
+	pte = (pa | PAGE_KERNEL);
+	__nds32__mtsr_dsb(kaddr, NDS32_SR_TLB_VPN);
+	__nds32__tlbop_rwlk(pte);
+	__nds32__isb();
+	return kaddr;
+}
+
+static inline void kunmap01(unsigned long kaddr)
+{
+	__nds32__tlbop_unlk(kaddr);
+	__nds32__tlbop_inv(kaddr);
+	__nds32__isb();
+}
+
+static inline unsigned long kremap1(unsigned long uaddr, unsigned long pa)
+{
+	unsigned long kaddr, pte;
+
+#define BASE_ADDR1 0xffff8000
+	kaddr = BASE_ADDR1 | (uaddr & L1_cache_info[DCACHE].aliasing_mask);
+	pte = (pa | PAGE_KERNEL);
+	__nds32__mtsr_dsb(kaddr, NDS32_SR_TLB_VPN);
+	__nds32__tlbop_rwlk(pte);
+	__nds32__isb();
+	return kaddr;
+}
+
+void flush_cache_mm(struct mm_struct *mm)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	cpu_dcache_wbinval_all();
+	cpu_icache_inval_all();
+	local_irq_restore(flags);
+}
+
+void flush_cache_dup_mm(struct mm_struct *mm)
+{
+}
+
+void flush_cache_range(struct vm_area_struct *vma,
+		       unsigned long start, unsigned long end)
+{
+	unsigned long flags;
+
+	if ((end - start) > 8 * PAGE_SIZE) {
+		cpu_dcache_wbinval_all();
+		if (vma->vm_flags & VM_EXEC)
+			cpu_icache_inval_all();
+		return;
+	}
+	local_irq_save(flags);
+	while (start < end) {
+		if (va_present(vma->vm_mm, start))
+			cpu_cache_wbinval_page(start, vma->vm_flags & VM_EXEC);
+		start += PAGE_SIZE;
+	}
+	local_irq_restore(flags);
+	return;
+}
+
+void flush_cache_page(struct vm_area_struct *vma,
+		      unsigned long addr, unsigned long pfn)
+{
+	unsigned long vto, flags;
+
+	local_irq_save(flags);
+	vto = kremap0(addr, pfn << PAGE_SHIFT);
+	cpu_cache_wbinval_page(vto, vma->vm_flags & VM_EXEC);
+	kunmap01(vto);
+	local_irq_restore(flags);
+}
+
+void flush_cache_vmap(unsigned long start, unsigned long end)
+{
+	cpu_dcache_wbinval_all();
+	cpu_icache_inval_all();
+}
+
+void flush_cache_vunmap(unsigned long start, unsigned long end)
+{
+	cpu_dcache_wbinval_all();
+	cpu_icache_inval_all();
+}
+
+void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
+		    struct page *to)
+{
+	cpu_dcache_wbinval_page((unsigned long)vaddr);
+	cpu_icache_inval_page((unsigned long)vaddr);
+	copy_page(vto, vfrom);
+	cpu_dcache_wbinval_page((unsigned long)vto);
+	cpu_icache_inval_page((unsigned long)vto);
+}
+
+void clear_user_page(void *addr, unsigned long vaddr, struct page *page)
+{
+	cpu_dcache_wbinval_page((unsigned long)vaddr);
+	cpu_icache_inval_page((unsigned long)vaddr);
+	clear_page(addr);
+	cpu_dcache_wbinval_page((unsigned long)addr);
+	cpu_icache_inval_page((unsigned long)addr);
+}
+
+void copy_user_highpage(struct page *to, struct page *from,
+			unsigned long vaddr, struct vm_area_struct *vma)
+{
+	unsigned long vto, vfrom, flags, kto, kfrom, pfrom, pto;
+	kto = ((unsigned long)page_address(to) & PAGE_MASK);
+	kfrom = ((unsigned long)page_address(from) & PAGE_MASK);
+	pto = page_to_phys(to);
+	pfrom = page_to_phys(from);
+
+	local_irq_save(flags);
+	if (aliasing(vaddr, (unsigned long)kfrom))
+		cpu_dcache_wb_page((unsigned long)kfrom);
+	vto = kremap0(vaddr, pto);
+	vfrom = kremap1(vaddr, pfrom);
+	copy_page((void *)vto, (void *)vfrom);
+	kunmap01(vfrom);
+	kunmap01(vto);
+	local_irq_restore(flags);
+}
+
+EXPORT_SYMBOL(copy_user_highpage);
+
+void clear_user_highpage(struct page *page, unsigned long vaddr)
+{
+	unsigned long vto, flags, kto;
+
+	kto = ((unsigned long)page_address(page) & PAGE_MASK);
+
+	local_irq_save(flags);
+	if (aliasing(kto, vaddr) && kto != 0) {
+		cpu_dcache_inval_page(kto);
+		cpu_icache_inval_page(kto);
+	}
+	vto = kremap0(vaddr, page_to_phys(page));
+	clear_page((void *)vto);
+	kunmap01(vto);
+	local_irq_restore(flags);
+}
+
+EXPORT_SYMBOL(clear_user_highpage);
+
+void flush_dcache_page(struct page *page)
+{
+	struct address_space *mapping;
+
+	mapping = page_mapping(page);
+	if (mapping && !mapping_mapped(mapping))
+		set_bit(PG_dcache_dirty, &page->flags);
+	else {
+		unsigned long kaddr, flags;
+
+		kaddr = (unsigned long)page_address(page);
+		local_irq_save(flags);
+		cpu_dcache_wbinval_page(kaddr);
+		if (mapping) {
+			unsigned long vaddr, kto;
+
+			vaddr = page->index << PAGE_SHIFT;
+			if (aliasing(vaddr, kaddr)) {
+				kto = kremap0(vaddr, page_to_phys(page));
+				cpu_dcache_wbinval_page(kto);
+				kunmap01(kto);
+			}
+		}
+		local_irq_restore(flags);
+	}
+}
+EXPORT_SYMBOL(flush_dcache_page);
+
+void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
+		       unsigned long vaddr, void *dst, void *src, int len)
+{
+	unsigned long line_size, start, end, vto, flags;
+
+	local_irq_save(flags);
+	vto = kremap0(vaddr, page_to_phys(page));
+	dst = (void *)(vto | (vaddr & (PAGE_SIZE - 1)));
+	memcpy(dst, src, len);
+	if (vma->vm_flags & VM_EXEC) {
+		line_size = L1_cache_info[DCACHE].line_size;
+		start = (unsigned long)dst & ~(line_size - 1);
+		end =
+		    ((unsigned long)dst + len + line_size - 1) & ~(line_size -
+								   1);
+		cpu_cache_wbinval_range(start, end, 1);
+	}
+	kunmap01(vto);
+	local_irq_restore(flags);
+}
+
+void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
+			 unsigned long vaddr, void *dst, void *src, int len)
+{
+	unsigned long vto, flags;
+
+	local_irq_save(flags);
+	vto = kremap0(vaddr, page_to_phys(page));
+	src = (void *)(vto | (vaddr & (PAGE_SIZE - 1)));
+	memcpy(dst, src, len);
+	kunmap01(vto);
+	local_irq_restore(flags);
+}
+
+void flush_anon_page(struct vm_area_struct *vma,
+		     struct page *page, unsigned long vaddr)
+{
+	unsigned long kaddr, flags, ktmp;
+	if (!PageAnon(page))
+		return;
+
+	if (vma->vm_mm != current->active_mm)
+		return;
+
+	local_irq_save(flags);
+	if (vma->vm_flags & VM_EXEC)
+		cpu_icache_inval_page(vaddr & PAGE_MASK);
+	kaddr = (unsigned long)page_address(page);
+	if (aliasing(vaddr, kaddr)) {
+		ktmp = kremap0(vaddr, page_to_phys(page));
+		cpu_dcache_wbinval_page(ktmp);
+		kunmap01(ktmp);
+	}
+	local_irq_restore(flags);
+}
+
+void flush_kernel_dcache_page(struct page *page)
+{
+	unsigned long flags;
+	local_irq_save(flags);
+	cpu_dcache_wbinval_page((unsigned long)page_address(page));
+	local_irq_restore(flags);
+}
+EXPORT_SYMBOL(flush_kernel_dcache_page);
+
+void flush_kernel_vmap_range(void *addr, int size)
+{
+	unsigned long flags;
+	local_irq_save(flags);
+	cpu_dcache_wb_range((unsigned long)addr, (unsigned long)addr +  size);
+	local_irq_restore(flags);
+}
+EXPORT_SYMBOL(flush_kernel_vmap_range);
+
+void invalidate_kernel_vmap_range(void *addr, int size)
+{
+	unsigned long flags;
+	local_irq_save(flags);
+	cpu_dcache_inval_range((unsigned long)addr, (unsigned long)addr + size);
+	local_irq_restore(flags);
+}
+EXPORT_SYMBOL(invalidate_kernel_vmap_range);
+#endif