[PATCH V3 12/22] LoongArch: Add memory management

[Huacai Chen]

This patch adds memory management support for LoongArch, including:
cache and tlb management, page fault handling and ioremap/mmap support.

Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
---
 arch/loongarch/include/asm/cache.h        |  13 +
 arch/loongarch/include/asm/cacheflush.h   |  79 +++
 arch/loongarch/include/asm/cacheops.h     |  33 ++
 arch/loongarch/include/asm/fixmap.h       |  15 +
 arch/loongarch/include/asm/hugetlb.h      |  79 +++
 arch/loongarch/include/asm/page.h         | 127 +++++
 arch/loongarch/include/asm/pgalloc.h      |  97 ++++
 arch/loongarch/include/asm/pgtable-bits.h | 139 +++++
 arch/loongarch/include/asm/pgtable.h      | 585 ++++++++++++++++++++++
 arch/loongarch/include/asm/shmparam.h     |  12 +
 arch/loongarch/include/asm/sparsemem.h    |  21 +
 arch/loongarch/include/asm/tlb.h          | 216 ++++++++
 arch/loongarch/include/asm/tlbflush.h     |  36 ++
 arch/loongarch/include/asm/vmalloc.h      |   4 +
 arch/loongarch/mm/cache.c                 | 153 ++++++
 arch/loongarch/mm/extable.c               |  22 +
 arch/loongarch/mm/fault.c                 | 248 +++++++++
 arch/loongarch/mm/hugetlbpage.c           |  87 ++++
 arch/loongarch/mm/init.c                  | 196 ++++++++
 arch/loongarch/mm/ioremap.c               |  27 +
 arch/loongarch/mm/maccess.c               |  10 +
 arch/loongarch/mm/mmap.c                  | 125 +++++
 arch/loongarch/mm/page.S                  |  84 ++++
 arch/loongarch/mm/pgtable.c               | 132 +++++
 arch/loongarch/mm/tlb.c                   | 287 +++++++++++
 arch/loongarch/mm/tlbex.S                 | 468 +++++++++++++++++
 26 files changed, 3295 insertions(+)
 create mode 100644 arch/loongarch/include/asm/cache.h
 create mode 100644 arch/loongarch/include/asm/cacheflush.h
 create mode 100644 arch/loongarch/include/asm/cacheops.h
 create mode 100644 arch/loongarch/include/asm/fixmap.h
 create mode 100644 arch/loongarch/include/asm/hugetlb.h
 create mode 100644 arch/loongarch/include/asm/page.h
 create mode 100644 arch/loongarch/include/asm/pgalloc.h
 create mode 100644 arch/loongarch/include/asm/pgtable-bits.h
 create mode 100644 arch/loongarch/include/asm/pgtable.h
 create mode 100644 arch/loongarch/include/asm/shmparam.h
 create mode 100644 arch/loongarch/include/asm/sparsemem.h
 create mode 100644 arch/loongarch/include/asm/tlb.h
 create mode 100644 arch/loongarch/include/asm/tlbflush.h
 create mode 100644 arch/loongarch/include/asm/vmalloc.h
 create mode 100644 arch/loongarch/mm/cache.c
 create mode 100644 arch/loongarch/mm/extable.c
 create mode 100644 arch/loongarch/mm/fault.c
 create mode 100644 arch/loongarch/mm/hugetlbpage.c
 create mode 100644 arch/loongarch/mm/init.c
 create mode 100644 arch/loongarch/mm/ioremap.c
 create mode 100644 arch/loongarch/mm/maccess.c
 create mode 100644 arch/loongarch/mm/mmap.c
 create mode 100644 arch/loongarch/mm/page.S
 create mode 100644 arch/loongarch/mm/pgtable.c
 create mode 100644 arch/loongarch/mm/tlb.c
 create mode 100644 arch/loongarch/mm/tlbex.S

diff --git a/arch/loongarch/include/asm/cache.h b/arch/loongarch/include/asm/cache.h
new file mode 100644
index 000000000000..e01c3c1c6ee6
--- /dev/null
+++ b/arch/loongarch/include/asm/cache.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_CACHE_H
+#define _ASM_CACHE_H
+
+#define L1_CACHE_SHIFT		CONFIG_L1_CACHE_SHIFT
+#define L1_CACHE_BYTES		(1 << L1_CACHE_SHIFT)
+
+#define __read_mostly __section(".data..read_mostly")
+
+#endif /* _ASM_CACHE_H */
diff --git a/arch/loongarch/include/asm/cacheflush.h b/arch/loongarch/include/asm/cacheflush.h
new file mode 100644
index 000000000000..214ec714a27b
--- /dev/null
+++ b/arch/loongarch/include/asm/cacheflush.h
@@ -0,0 +1,79 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_CACHEFLUSH_H
+#define _ASM_CACHEFLUSH_H
+
+#include <linux/mm.h>
+#include <asm/cpu-features.h>
+#include <asm/cacheops.h>
+
+/*
+ * This flag is used to indicate that the page pointed to by a pte
+ * is dirty and requires cleaning before returning it to the user.
+ */
+#define PG_dcache_dirty			PG_arch_1
+
+#define Page_dcache_dirty(page)		\
+	test_bit(PG_dcache_dirty, &(page)->flags)
+#define SetPageDcacheDirty(page)	\
+	set_bit(PG_dcache_dirty, &(page)->flags)
+#define ClearPageDcacheDirty(page)	\
+	clear_bit(PG_dcache_dirty, &(page)->flags)
+
+extern void local_flush_icache_range(unsigned long start, unsigned long end);
+
+#define flush_icache_range	local_flush_icache_range
+#define flush_icache_user_range	local_flush_icache_range
+
+extern void copy_to_user_page(struct vm_area_struct *vma,
+	struct page *page, unsigned long vaddr, void *dst, const void *src,
+	unsigned long 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);
+
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
+
+#define flush_cache_all()				do { } while (0)
+#define flush_cache_mm(mm)				do { } while (0)
+#define flush_cache_dup_mm(mm)				do { } while (0)
+#define flush_cache_range(vma, start, end)		do { } while (0)
+#define flush_cache_page(vma, vmaddr, pfn)		do { } while (0)
+#define flush_cache_vmap(start, end)			do { } while (0)
+#define flush_cache_vunmap(start, end)			do { } while (0)
+#define flush_icache_page(vma, page)			do { } while (0)
+#define flush_icache_user_page(vma, page, addr, len)	do { } while (0)
+#define flush_dcache_page(page)				do { } while (0)
+#define flush_dcache_mmap_lock(mapping)			do { } while (0)
+#define flush_dcache_mmap_unlock(mapping)		do { } while (0)
+
+#define cache_op(op, addr)						\
+	__asm__ __volatile__(						\
+	"	cacop	%0, %1					\n"	\
+	:								\
+	: "i" (op), "R" (*(unsigned char *)(addr)))
+
+static inline void flush_icache_line_indexed(unsigned long addr)
+{
+	cache_op(Index_Invalidate_I, addr);
+}
+
+static inline void flush_dcache_line_indexed(unsigned long addr)
+{
+	cache_op(Index_Writeback_Inv_D, addr);
+}
+
+static inline void flush_icache_line(unsigned long addr)
+{
+	cache_op(Hit_Invalidate_I, addr);
+}
+
+static inline void flush_dcache_line(unsigned long addr)
+{
+	cache_op(Hit_Writeback_Inv_D, addr);
+}
+
+#endif /* _ASM_CACHEFLUSH_H */
diff --git a/arch/loongarch/include/asm/cacheops.h b/arch/loongarch/include/asm/cacheops.h
new file mode 100644
index 000000000000..f51ff1eaa16d
--- /dev/null
+++ b/arch/loongarch/include/asm/cacheops.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Cache operations for the cache instruction.
+ *
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#ifndef __ASM_CACHEOPS_H
+#define __ASM_CACHEOPS_H
+
+/*
+ * Most cache ops are split into a 2 bit field identifying the cache, and a 3
+ * bit field identifying the cache operation.
+ */
+#define CacheOp_Cache			0x03
+#define CacheOp_Op			0x1c
+
+#define Cache_I				0x00
+#define Cache_D				0x01
+#define Cache_V				0x02
+#define Cache_S				0x03
+
+#define Index_Invalidate		0x08
+#define Index_Writeback_Inv		0x08
+#define Hit_Invalidate			0x10
+#define Hit_Writeback_Inv		0x10
+#define CacheOp_User_Defined		0x18
+
+#define Index_Invalidate_I		(Cache_I | Index_Invalidate)
+#define Index_Writeback_Inv_D		(Cache_D | Index_Writeback_Inv)
+#define Hit_Invalidate_I		(Cache_I | Hit_Invalidate)
+#define Hit_Writeback_Inv_D		(Cache_D | Hit_Writeback_Inv)
+
+#endif	/* __ASM_CACHEOPS_H */
diff --git a/arch/loongarch/include/asm/fixmap.h b/arch/loongarch/include/asm/fixmap.h
new file mode 100644
index 000000000000..2ba4df6ec88d
--- /dev/null
+++ b/arch/loongarch/include/asm/fixmap.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * fixmap.h: compile-time virtual memory allocation
+ *
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+
+#ifndef _ASM_FIXMAP_H
+#define _ASM_FIXMAP_H
+
+#include <asm/page.h>
+
+#define NR_FIX_BTMAPS 64
+
+#endif
diff --git a/arch/loongarch/include/asm/hugetlb.h b/arch/loongarch/include/asm/hugetlb.h
new file mode 100644
index 000000000000..5548ab8ceac2
--- /dev/null
+++ b/arch/loongarch/include/asm/hugetlb.h
@@ -0,0 +1,79 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+
+#ifndef __ASM_HUGETLB_H
+#define __ASM_HUGETLB_H
+
+#include <asm/page.h>
+
+uint64_t pmd_to_entrylo(unsigned long pmd_val);
+
+#define __HAVE_ARCH_PREPARE_HUGEPAGE_RANGE
+static inline int prepare_hugepage_range(struct file *file,
+					 unsigned long addr,
+					 unsigned long len)
+{
+	unsigned long task_size = STACK_TOP;
+	struct hstate *h = hstate_file(file);
+
+	if (len & ~huge_page_mask(h))
+		return -EINVAL;
+	if (addr & ~huge_page_mask(h))
+		return -EINVAL;
+	if (len > task_size)
+		return -ENOMEM;
+	if (task_size - len < addr)
+		return -EINVAL;
+	return 0;
+}
+
+#define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
+static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
+					    unsigned long addr, pte_t *ptep)
+{
+	pte_t clear;
+	pte_t pte = *ptep;
+
+	pte_val(clear) = (unsigned long)invalid_pte_table;
+	set_pte_at(mm, addr, ptep, clear);
+	return pte;
+}
+
+#define __HAVE_ARCH_HUGE_PTEP_CLEAR_FLUSH
+static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
+					 unsigned long addr, pte_t *ptep)
+{
+	flush_tlb_page(vma, addr & huge_page_mask(hstate_vma(vma)));
+}
+
+#define __HAVE_ARCH_HUGE_PTE_NONE
+static inline int huge_pte_none(pte_t pte)
+{
+	unsigned long val = pte_val(pte) & ~_PAGE_GLOBAL;
+	return !val || (val == (unsigned long)invalid_pte_table);
+}
+
+#define __HAVE_ARCH_HUGE_PTEP_SET_ACCESS_FLAGS
+static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
+					     unsigned long addr,
+					     pte_t *ptep, pte_t pte,
+					     int dirty)
+{
+	int changed = !pte_same(*ptep, pte);
+
+	if (changed) {
+		set_pte_at(vma->vm_mm, addr, ptep, pte);
+		/*
+		 * There could be some standard sized pages in there,
+		 * get them all.
+		 */
+		flush_tlb_range(vma, addr, addr + HPAGE_SIZE);
+	}
+	return changed;
+}
+
+#include <asm-generic/hugetlb.h>
+
+#endif /* __ASM_HUGETLB_H */
diff --git a/arch/loongarch/include/asm/page.h b/arch/loongarch/include/asm/page.h
new file mode 100644
index 000000000000..e626baa43f9f
--- /dev/null
+++ b/arch/loongarch/include/asm/page.h
@@ -0,0 +1,127 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_PAGE_H
+#define _ASM_PAGE_H
+
+#include <linux/const.h>
+
+/*
+ * PAGE_SHIFT determines the page size
+ */
+#ifdef CONFIG_PAGE_SIZE_4KB
+#define PAGE_SHIFT	12
+#endif
+#ifdef CONFIG_PAGE_SIZE_16KB
+#define PAGE_SHIFT	14
+#endif
+#ifdef CONFIG_PAGE_SIZE_64KB
+#define PAGE_SHIFT	16
+#endif
+#define PAGE_SIZE	(_AC(1, UL) << PAGE_SHIFT)
+#define PAGE_MASK	(~(PAGE_SIZE - 1))
+
+#define HPAGE_SHIFT	(PAGE_SHIFT + PAGE_SHIFT - 3)
+#define HPAGE_SIZE	(_AC(1, UL) << HPAGE_SHIFT)
+#define HPAGE_MASK	(~(HPAGE_SIZE - 1))
+#define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
+
+#ifndef __ASSEMBLY__
+
+#include <linux/kernel.h>
+#include <linux/pfn.h>
+
+/*
+ * It's normally defined only for FLATMEM config but it's
+ * used in our early mem init code for all memory models.
+ * So always define it.
+ */
+#define ARCH_PFN_OFFSET	PFN_UP(PHYS_OFFSET)
+
+extern void clear_page(void *page);
+extern void copy_page(void *to, void *from);
+
+extern unsigned long shm_align_mask;
+
+struct page;
+
+static inline void clear_user_page(void *addr, unsigned long vaddr,
+	struct page *page)
+{
+	clear_page(addr);
+}
+
+struct vm_area_struct;
+extern void copy_user_highpage(struct page *to, struct page *from,
+	unsigned long vaddr, struct vm_area_struct *vma);
+
+#define __HAVE_ARCH_COPY_USER_HIGHPAGE
+
+/*
+ * These are used to make use of C type-checking..
+ */
+typedef struct { unsigned long pte; } pte_t;
+#define pte_val(x)	((x).pte)
+#define __pte(x)	((pte_t) { (x) })
+typedef struct page *pgtable_t;
+
+/*
+ * Finall the top of the hierarchy, the pgd
+ */
+typedef struct { unsigned long pgd; } pgd_t;
+#define pgd_val(x)	((x).pgd)
+#define __pgd(x)	((pgd_t) { (x) })
+
+/*
+ * Manipulate page protection bits
+ */
+typedef struct { unsigned long pgprot; } pgprot_t;
+#define pgprot_val(x)	((x).pgprot)
+#define __pgprot(x)	((pgprot_t) { (x) })
+#define pte_pgprot(x)	__pgprot(pte_val(x) & ~_PFN_MASK)
+
+#define ptep_buddy(x)	((pte_t *)((unsigned long)(x) ^ sizeof(pte_t)))
+
+/*
+ * __pa()/__va() should be used only during mem init.
+ */
+#define __pa(x)		PHYSADDR(x)
+#define __va(x)		((void *)((unsigned long)(x) + PAGE_OFFSET - PHYS_OFFSET))
+
+#ifndef __pa_symbol
+#define __pa_symbol(x)	__pa(RELOC_HIDE((unsigned long)(x), 0))
+#endif
+
+#define pfn_to_kaddr(pfn)	__va((pfn) << PAGE_SHIFT)
+
+#ifdef CONFIG_FLATMEM
+
+static inline int pfn_valid(unsigned long pfn)
+{
+	/* avoid <linux/mm.h> include hell */
+	extern unsigned long max_mapnr;
+	unsigned long pfn_offset = ARCH_PFN_OFFSET;
+
+	return pfn >= pfn_offset && pfn < max_mapnr;
+}
+
+#endif
+
+#define virt_to_pfn(kaddr)	PFN_DOWN(virt_to_phys((void *)(kaddr)))
+#define virt_to_page(kaddr)	pfn_to_page(virt_to_pfn(kaddr))
+
+extern int __virt_addr_valid(volatile void *kaddr);
+#define virt_addr_valid(kaddr)	__virt_addr_valid((volatile void *)(kaddr))
+
+#define VM_DATA_DEFAULT_FLAGS \
+	(VM_READ | VM_WRITE | \
+	 ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0) | \
+	 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+
+#include <asm-generic/memory_model.h>
+#include <asm-generic/getorder.h>
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* _ASM_PAGE_H */
diff --git a/arch/loongarch/include/asm/pgalloc.h b/arch/loongarch/include/asm/pgalloc.h
new file mode 100644
index 000000000000..03e87961dd65
--- /dev/null
+++ b/arch/loongarch/include/asm/pgalloc.h
@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_PGALLOC_H
+#define _ASM_PGALLOC_H
+
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+
+#define __HAVE_ARCH_PMD_ALLOC_ONE
+#define __HAVE_ARCH_PUD_ALLOC_ONE
+#include <asm-generic/pgalloc.h>
+
+static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
+	pte_t *pte)
+{
+	set_pmd(pmd, __pmd((unsigned long)pte));
+}
+
+static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
+	pgtable_t pte)
+{
+	set_pmd(pmd, __pmd((unsigned long)page_address(pte)));
+}
+
+/*
+ * Initialize a new pmd table with invalid pointers.
+ */
+extern void pmd_init(unsigned long page, unsigned long pagetable);
+
+#ifndef __PAGETABLE_PMD_FOLDED
+
+static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
+{
+	set_pud(pud, __pud((unsigned long)pmd));
+}
+#endif
+
+/*
+ * Initialize a new pgd / pmd table with invalid pointers.
+ */
+extern void pgd_init(unsigned long page);
+extern pgd_t *pgd_alloc(struct mm_struct *mm);
+
+#define __pte_free_tlb(tlb, pte, address)			\
+do {							\
+	pgtable_pte_page_dtor(pte);			\
+	tlb_remove_page((tlb), pte);			\
+} while (0)
+
+#ifndef __PAGETABLE_PMD_FOLDED
+
+static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
+{
+	pmd_t *pmd;
+
+	pmd = (pmd_t *) __get_free_pages(GFP_KERNEL, PMD_ORDER);
+	if (pmd)
+		pmd_init((unsigned long)pmd, (unsigned long)invalid_pte_table);
+	return pmd;
+}
+
+#define __pmd_free_tlb(tlb, x, addr)	pmd_free((tlb)->mm, x)
+
+#endif
+
+#ifndef __PAGETABLE_PUD_FOLDED
+
+static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
+{
+	pud_t *pud;
+
+	pud = (pud_t *) __get_free_pages(GFP_KERNEL, PUD_ORDER);
+	if (pud)
+		pud_init((unsigned long)pud, (unsigned long)invalid_pmd_table);
+	return pud;
+}
+
+static inline void pud_free(struct mm_struct *mm, pud_t *pud)
+{
+	free_pages((unsigned long)pud, PUD_ORDER);
+}
+
+static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
+{
+	set_p4d(p4d, __p4d((unsigned long)pud));
+}
+
+#define __pud_free_tlb(tlb, x, addr)	pud_free((tlb)->mm, x)
+
+#endif /* __PAGETABLE_PUD_FOLDED */
+
+extern void pagetable_init(void);
+
+#endif /* _ASM_PGALLOC_H */
diff --git a/arch/loongarch/include/asm/pgtable-bits.h b/arch/loongarch/include/asm/pgtable-bits.h
new file mode 100644
index 000000000000..446c97e85610
--- /dev/null
+++ b/arch/loongarch/include/asm/pgtable-bits.h
@@ -0,0 +1,139 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_PGTABLE_BITS_H
+#define _ASM_PGTABLE_BITS_H
+
+/* Page table bits */
+
+#define	_PAGE_VALID_SHIFT	0
+#define	_PAGE_ACCESSED_SHIFT	0  /* Reuse Valid for Accessed */
+#define	_PAGE_DIRTY_SHIFT	1
+#define	_PAGE_PLV_SHIFT		2  /* 2~3, two bits */
+#define	_CACHE_SHIFT		4  /* 4~5, two bits */
+#define	_PAGE_GLOBAL_SHIFT	6
+#define	_PAGE_HUGE_SHIFT	6  /* HUGE is a PMD bit */
+#define	_PAGE_PRESENT_SHIFT	7
+#define	_PAGE_WRITE_SHIFT	8
+#define	_PAGE_MODIFIED_SHIFT	9
+#define	_PAGE_PROTNONE_SHIFT	10
+#define	_PAGE_SPECIAL_SHIFT	11
+#define	_PAGE_HGLOBAL_SHIFT	12 /* HGlobal is a PMD bit */
+#define	_PAGE_PFN_SHIFT		12
+#define	_PAGE_PFN_END_SHIFT	48
+#define	_PAGE_NO_READ_SHIFT	61
+#define	_PAGE_NO_EXEC_SHIFT	62
+#define	_PAGE_RPLV_SHIFT	63
+
+/* Used only by software */
+#define _PAGE_PRESENT		(_ULCAST_(1) << _PAGE_PRESENT_SHIFT)
+#define _PAGE_WRITE		(_ULCAST_(1) << _PAGE_WRITE_SHIFT)
+#define _PAGE_ACCESSED		(_ULCAST_(1) << _PAGE_ACCESSED_SHIFT)
+#define _PAGE_MODIFIED		(_ULCAST_(1) << _PAGE_MODIFIED_SHIFT)
+#define _PAGE_PROTNONE		(_ULCAST_(1) << _PAGE_PROTNONE_SHIFT)
+#define _PAGE_SPECIAL		(_ULCAST_(1) << _PAGE_SPECIAL_SHIFT)
+
+/* Used by TLB hardware (placed in EntryLo*) */
+#define _PAGE_VALID		(_ULCAST_(1) << _PAGE_VALID_SHIFT)
+#define _PAGE_DIRTY		(_ULCAST_(1) << _PAGE_DIRTY_SHIFT)
+#define _PAGE_PLV		(_ULCAST_(3) << _PAGE_PLV_SHIFT)
+#define _PAGE_GLOBAL		(_ULCAST_(1) << _PAGE_GLOBAL_SHIFT)
+#define _PAGE_HUGE		(_ULCAST_(1) << _PAGE_HUGE_SHIFT)
+#define _PAGE_HGLOBAL		(_ULCAST_(1) << _PAGE_HGLOBAL_SHIFT)
+#define _PAGE_NO_READ		(_ULCAST_(1) << _PAGE_NO_READ_SHIFT)
+#define _PAGE_NO_EXEC		(_ULCAST_(1) << _PAGE_NO_EXEC_SHIFT)
+#define _PAGE_RPLV		(_ULCAST_(1) << _PAGE_RPLV_SHIFT)
+#define _CACHE_MASK		(_ULCAST_(3) << _CACHE_SHIFT)
+#define _PFN_SHIFT		(PAGE_SHIFT - 12 + _PAGE_PFN_SHIFT)
+
+#define _PAGE_USER	(PLV_USER << _PAGE_PLV_SHIFT)
+#define _PAGE_KERN	(PLV_KERN << _PAGE_PLV_SHIFT)
+
+#define _PFN_MASK (~((_ULCAST_(1) << (_PFN_SHIFT)) - 1) & \
+		  ((_ULCAST_(1) << (_PAGE_PFN_END_SHIFT)) - 1))
+
+/*
+ * Cache attributes
+ */
+
+#ifndef _CACHE_SUC
+#define _CACHE_SUC			(0<<_CACHE_SHIFT) /* Strong-ordered UnCached */
+#endif
+#ifndef _CACHE_CC
+#define _CACHE_CC			(1<<_CACHE_SHIFT) /* Coherent Cached */
+#endif
+#ifndef _CACHE_WUC
+#define _CACHE_WUC			(2<<_CACHE_SHIFT) /* Weak-ordered UnCached */
+#endif
+
+#define __READABLE	(_PAGE_VALID)
+#define __WRITEABLE	(_PAGE_DIRTY | _PAGE_WRITE)
+
+#define _PAGE_CHG_MASK	(_PAGE_SPECIAL | _PFN_MASK | _CACHE_MASK | _PAGE_PLV)
+#define _HPAGE_CHG_MASK	(_PAGE_SPECIAL | _PFN_MASK | _CACHE_MASK | _PAGE_PLV | _PAGE_HUGE)
+
+#define PAGE_NONE	__pgprot(_PAGE_PROTNONE | _PAGE_NO_READ | \
+				 _PAGE_USER | _CACHE_CC)
+#define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_WRITE | \
+				 _PAGE_USER | _CACHE_CC)
+#define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _CACHE_CC)
+
+#define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
+				 _PAGE_GLOBAL | _PAGE_KERN | _CACHE_CC)
+#define PAGE_KERNEL_SUC __pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
+				 _PAGE_GLOBAL | _PAGE_KERN |  _CACHE_SUC)
+#define PAGE_KERNEL_WUC __pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
+				 _PAGE_GLOBAL | _PAGE_KERN |  _CACHE_WUC)
+
+#define __P000 __pgprot(_CACHE_CC | _PAGE_PROTNONE | _PAGE_NO_EXEC | _PAGE_NO_READ)
+#define __P001 __pgprot(_CACHE_CC | _PAGE_VALID | _PAGE_USER | _PAGE_PRESENT | _PAGE_NO_EXEC)
+#define __P010 __pgprot(_CACHE_CC | _PAGE_VALID | _PAGE_USER | _PAGE_PRESENT | _PAGE_NO_EXEC)
+#define __P011 __pgprot(_CACHE_CC | _PAGE_VALID | _PAGE_USER | _PAGE_PRESENT | _PAGE_NO_EXEC)
+#define __P100 __pgprot(_CACHE_CC | _PAGE_VALID | _PAGE_USER | _PAGE_PRESENT)
+#define __P101 __pgprot(_CACHE_CC | _PAGE_VALID | _PAGE_USER | _PAGE_PRESENT)
+#define __P110 __pgprot(_CACHE_CC | _PAGE_VALID | _PAGE_USER | _PAGE_PRESENT)
+#define __P111 __pgprot(_CACHE_CC | _PAGE_VALID | _PAGE_USER | _PAGE_PRESENT)
+
+#define __S000 __pgprot(_CACHE_CC | _PAGE_PROTNONE | _PAGE_NO_EXEC | _PAGE_NO_READ)
+#define __S001 __pgprot(_CACHE_CC | _PAGE_VALID | _PAGE_USER | _PAGE_PRESENT | _PAGE_NO_EXEC)
+#define __S010 __pgprot(_CACHE_CC | _PAGE_VALID | _PAGE_USER | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE)
+#define __S011 __pgprot(_CACHE_CC | _PAGE_VALID | _PAGE_USER | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE)
+#define __S100 __pgprot(_CACHE_CC | _PAGE_VALID | _PAGE_USER | _PAGE_PRESENT)
+#define __S101 __pgprot(_CACHE_CC | _PAGE_VALID | _PAGE_USER | _PAGE_PRESENT)
+#define __S110 __pgprot(_CACHE_CC | _PAGE_VALID | _PAGE_USER | _PAGE_PRESENT | _PAGE_WRITE)
+#define __S111 __pgprot(_CACHE_CC | _PAGE_VALID | _PAGE_USER | _PAGE_PRESENT | _PAGE_WRITE)
+
+#ifndef __ASSEMBLY__
+
+/*
+ * Macro to make mark a page protection value as "uncacheable".	 Note
+ * that "protection" is really a misnomer here as the protection value
+ * contains the memory attribute bits, dirty bits, and various other
+ * bits as well.
+ */
+#define pgprot_noncached pgprot_noncached
+
+static inline pgprot_t pgprot_noncached(pgprot_t _prot)
+{
+	unsigned long prot = pgprot_val(_prot);
+
+	prot = (prot & ~_CACHE_MASK) | _CACHE_SUC;
+
+	return __pgprot(prot);
+}
+
+#define pgprot_writecombine pgprot_writecombine
+
+static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
+{
+	unsigned long prot = pgprot_val(_prot);
+
+	prot = (prot & ~_CACHE_MASK) | _CACHE_WUC;
+
+	return __pgprot(prot);
+}
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* _ASM_PGTABLE_BITS_H */
diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h
new file mode 100644
index 000000000000..0fb709e751e9
--- /dev/null
+++ b/arch/loongarch/include/asm/pgtable.h
@@ -0,0 +1,585 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ *
+ * Derived from MIPS:
+ * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 2003 Ralf Baechle
+ * Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
+ */
+#ifndef _ASM_PGTABLE_H
+#define _ASM_PGTABLE_H
+
+#include <linux/compiler.h>
+#include <asm/addrspace.h>
+#include <asm/pgtable-bits.h>
+
+#if CONFIG_PGTABLE_LEVELS == 2
+#include <asm-generic/pgtable-nopmd.h>
+#elif CONFIG_PGTABLE_LEVELS == 3
+#include <asm-generic/pgtable-nopud.h>
+#else
+#include <asm-generic/pgtable-nop4d.h>
+#endif
+
+#define PGD_ORDER		0
+#define PUD_ORDER		0
+#define PMD_ORDER		0
+#define PTE_ORDER		0
+
+#if CONFIG_PGTABLE_LEVELS == 2
+#define PGDIR_SHIFT	(PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 3))
+#elif CONFIG_PGTABLE_LEVELS == 3
+#define PMD_SHIFT	(PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 3))
+#define PMD_SIZE	(1UL << PMD_SHIFT)
+#define PMD_MASK	(~(PMD_SIZE-1))
+#define PGDIR_SHIFT	(PMD_SHIFT + (PAGE_SHIFT + PMD_ORDER - 3))
+#elif CONFIG_PGTABLE_LEVELS == 4
+#define PMD_SHIFT	(PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 3))
+#define PMD_SIZE	(1UL << PMD_SHIFT)
+#define PMD_MASK	(~(PMD_SIZE-1))
+#define PUD_SHIFT	(PMD_SHIFT + (PAGE_SHIFT + PMD_ORDER - 3))
+#define PUD_SIZE	(1UL << PUD_SHIFT)
+#define PUD_MASK	(~(PUD_SIZE-1))
+#define PGDIR_SHIFT	(PUD_SHIFT + (PAGE_SHIFT + PUD_ORDER - 3))
+#endif
+
+#define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
+#define PGDIR_MASK	(~(PGDIR_SIZE-1))
+
+#define VA_BITS		(PGDIR_SHIFT + (PAGE_SHIFT + PGD_ORDER - 3))
+
+#define PTRS_PER_PGD	((PAGE_SIZE << PGD_ORDER) >> 3)
+#if CONFIG_PGTABLE_LEVELS > 3
+#define PTRS_PER_PUD	((PAGE_SIZE << PUD_ORDER) >> 3)
+#endif
+#if CONFIG_PGTABLE_LEVELS > 2
+#define PTRS_PER_PMD	((PAGE_SIZE << PMD_ORDER) >> 3)
+#endif
+#define PTRS_PER_PTE	((PAGE_SIZE << PTE_ORDER) >> 3)
+
+#define USER_PTRS_PER_PGD       ((TASK_SIZE64 / PGDIR_SIZE)?(TASK_SIZE64 / PGDIR_SIZE):1)
+#define FIRST_USER_ADDRESS	0UL
+
+#ifndef __ASSEMBLY__
+
+#include <linux/mm_types.h>
+#include <linux/mmzone.h>
+#include <asm/fixmap.h>
+#include <asm/io.h>
+
+struct mm_struct;
+struct vm_area_struct;
+
+/*
+ * ZERO_PAGE is a global shared page that is always zero; used
+ * for zero-mapped memory areas etc..
+ */
+
+extern unsigned long empty_zero_page;
+extern unsigned long zero_page_mask;
+
+#define ZERO_PAGE(vaddr) \
+	(virt_to_page((void *)(empty_zero_page + (((unsigned long)(vaddr)) & zero_page_mask))))
+#define __HAVE_COLOR_ZERO_PAGE
+
+/*
+ * TLB refill handlers may also map the vmalloc area into xkvrange.
+ * Avoid the first couple of pages so NULL pointer dereferences will
+ * still reliably trap.
+ */
+#define VMALLOC_START	(vm_map_base + PCI_IOSIZE + (2 * PAGE_SIZE))
+#define VMALLOC_END	\
+	(vm_map_base +	\
+	 min(PTRS_PER_PGD * PTRS_PER_PUD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE, (1UL << cpu_vabits)) - PMD_SIZE)
+
+#define pte_ERROR(e) \
+	pr_err("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
+#ifndef __PAGETABLE_PMD_FOLDED
+#define pmd_ERROR(e) \
+	pr_err("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
+#endif
+#ifndef __PAGETABLE_PUD_FOLDED
+#define pud_ERROR(e) \
+	pr_err("%s:%d: bad pud %016lx.\n", __FILE__, __LINE__, pud_val(e))
+#endif
+#define pgd_ERROR(e) \
+	pr_err("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
+
+extern pte_t invalid_pte_table[PTRS_PER_PTE];
+
+#ifndef __PAGETABLE_PUD_FOLDED
+/*
+ * For 4-level pagetables we defines these ourselves, for 3-level the
+ * definitions are below, for 2-level the
+ * definitions are supplied by <asm-generic/pgtable-nopmd.h>.
+ */
+typedef struct { unsigned long pud; } pud_t;
+#define pud_val(x)	((x).pud)
+#define __pud(x)	((pud_t) { (x) })
+
+extern pud_t invalid_pud_table[PTRS_PER_PUD];
+
+/*
+ * Empty pgd entries point to the invalid_pud_table.
+ */
+static inline int p4d_none(p4d_t p4d)
+{
+	return p4d_val(p4d) == (unsigned long)invalid_pud_table;
+}
+
+static inline int p4d_bad(p4d_t p4d)
+{
+	if (unlikely(p4d_val(p4d) & ~PAGE_MASK))
+		return 1;
+
+	return 0;
+}
+
+static inline int p4d_present(p4d_t p4d)
+{
+	return p4d_val(p4d) != (unsigned long)invalid_pud_table;
+}
+
+static inline void p4d_clear(pgd_t *p4dp)
+{
+	p4d_val(*p4dp) = (unsigned long)invalid_pud_table;
+}
+
+static inline pud_t *p4d_pgtable(p4d_t p4d)
+{
+	return (pud_t *)p4d_val(p4d);
+}
+
+static inline void set_p4d(pgd_t *p4d, pgd_t p4dval)
+{
+	*p4d = p4dval;
+}
+
+#endif
+
+#ifndef __PAGETABLE_PMD_FOLDED
+/*
+ * For 3-level pagetables we defines these ourselves, for 2-level the
+ * definitions are supplied by <asm-generic/pgtable-nopmd.h>.
+ */
+typedef struct { unsigned long pmd; } pmd_t;
+#define pmd_val(x)	((x).pmd)
+#define __pmd(x)	((pmd_t) { (x) })
+
+
+extern pmd_t invalid_pmd_table[PTRS_PER_PMD];
+#endif
+
+/*
+ * Empty pgd/pmd entries point to the invalid_pte_table.
+ */
+static inline int pmd_none(pmd_t pmd)
+{
+	return pmd_val(pmd) == (unsigned long) invalid_pte_table;
+}
+
+static inline int pmd_bad(pmd_t pmd)
+{
+	/* pmd_huge(pmd) but inline */
+	if (unlikely(pmd_val(pmd) & _PAGE_HUGE))
+		return 0;
+
+	if (unlikely(pmd_val(pmd) & ~PAGE_MASK))
+		return 1;
+
+	return 0;
+}
+
+static inline int pmd_present(pmd_t pmd)
+{
+	if (unlikely(pmd_val(pmd) & _PAGE_HUGE))
+		return !!(pmd_val(pmd) & (_PAGE_PRESENT | _PAGE_PROTNONE));
+
+	return pmd_val(pmd) != (unsigned long) invalid_pte_table;
+}
+
+static inline void pmd_clear(pmd_t *pmdp)
+{
+	pmd_val(*pmdp) = ((unsigned long) invalid_pte_table);
+}
+#ifndef __PAGETABLE_PMD_FOLDED
+
+/*
+ * Empty pud entries point to the invalid_pmd_table.
+ */
+static inline int pud_none(pud_t pud)
+{
+	return pud_val(pud) == (unsigned long) invalid_pmd_table;
+}
+
+static inline int pud_bad(pud_t pud)
+{
+	return pud_val(pud) & ~PAGE_MASK;
+}
+
+static inline int pud_present(pud_t pud)
+{
+	return pud_val(pud) != (unsigned long) invalid_pmd_table;
+}
+
+static inline void pud_clear(pud_t *pudp)
+{
+	pud_val(*pudp) = ((unsigned long) invalid_pmd_table);
+}
+#endif
+
+#define pte_page(x)		pfn_to_page(pte_pfn(x))
+
+#define pte_pfn(x)		((unsigned long)(((x).pte & _PFN_MASK) >> _PFN_SHIFT))
+#define pfn_pte(pfn, prot)	__pte(((pfn) << _PFN_SHIFT) | pgprot_val(prot))
+#define pfn_pmd(pfn, prot)	__pmd(((pfn) << _PFN_SHIFT) | pgprot_val(prot))
+
+#define __pgd_offset(address)	pgd_index(address)
+#define __pud_offset(address)	(((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
+#define __pmd_offset(address)	pmd_index(address)
+
+#ifndef __PAGETABLE_PMD_FOLDED
+static inline pmd_t *pud_pgtable(pud_t pud)
+{
+	return (pmd_t *)pud_val(pud);
+}
+#define pud_phys(pud)		virt_to_phys((void *)pud_val(pud))
+#define pud_page(pud)		(pfn_to_page(pud_phys(pud) >> PAGE_SHIFT))
+
+#endif
+
+/*
+ * Initialize a new pgd / pmd table with invalid pointers.
+ */
+extern void pgd_init(unsigned long page);
+extern void pud_init(unsigned long page, unsigned long pagetable);
+extern void pmd_init(unsigned long page, unsigned long pagetable);
+
+/*
+ * Non-present pages:  high 40 bits are offset, next 8 bits type,
+ * low 16 bits zero.
+ */
+static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset)
+{ pte_t pte; pte_val(pte) = (type << 16) | (offset << 24); return pte; }
+
+#define __swp_type(x)		(((x).val >> 16) & 0xff)
+#define __swp_offset(x)		((x).val >> 24)
+#define __swp_entry(type, offset) ((swp_entry_t) { pte_val(mk_swap_pte((type), (offset))) })
+#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
+#define __swp_entry_to_pte(x)	((pte_t) { (x).val })
+
+extern void paging_init(void);
+
+/*
+ * Conversion functions: convert a page and protection to a page entry,
+ * and a page entry and page directory to the page they refer to.
+ */
+#define pmd_phys(pmd)		virt_to_phys((void *)pmd_val(pmd))
+
+#define __pmd_page(pmd)		(pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
+#ifndef CONFIG_TRANSPARENT_HUGEPAGE
+#define pmd_page(pmd)		__pmd_page(pmd)
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE  */
+
+#define pmd_page_vaddr(pmd)	pmd_val(pmd)
+
+static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
+			      pte_t *ptep, pte_t pteval);
+
+#define pte_none(pte)		(!(pte_val(pte) & ~_PAGE_GLOBAL))
+#define pte_present(pte)	(pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROTNONE))
+#define pte_no_exec(pte)	(pte_val(pte) & _PAGE_NO_EXEC)
+
+static inline void set_pte(pte_t *ptep, pte_t pteval)
+{
+	*ptep = pteval;
+	if (pte_val(pteval) & _PAGE_GLOBAL) {
+		pte_t *buddy = ptep_buddy(ptep);
+		/*
+		 * Make sure the buddy is global too (if it's !none,
+		 * it better already be global)
+		 */
+		if (pte_none(*buddy))
+			pte_val(*buddy) = pte_val(*buddy) | _PAGE_GLOBAL;
+	}
+}
+
+static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+	/* Preserve global status for the pair */
+	if (pte_val(*ptep_buddy(ptep)) & _PAGE_GLOBAL)
+		set_pte_at(mm, addr, ptep, __pte(_PAGE_GLOBAL));
+	else
+		set_pte_at(mm, addr, ptep, __pte(0));
+}
+
+static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
+			      pte_t *ptep, pte_t pteval)
+{
+	extern void __update_cache(unsigned long address, pte_t pte);
+
+	if (!pte_present(pteval))
+		goto cache_sync_done;
+
+	if (pte_present(*ptep) && (pte_pfn(*ptep) == pte_pfn(pteval)))
+		goto cache_sync_done;
+
+	__update_cache(addr, pteval);
+cache_sync_done:
+	set_pte(ptep, pteval);
+}
+
+/*
+ * (pmds are folded into puds so this doesn't get actually called,
+ * but the define is needed for a generic inline function.)
+ */
+#define set_pmd(pmdptr, pmdval) do { *(pmdptr) = (pmdval); } while (0)
+
+#ifndef __PAGETABLE_PMD_FOLDED
+/*
+ * (puds are folded into pgds so this doesn't get actually called,
+ * but the define is needed for a generic inline function.)
+ */
+#define set_pud(pudptr, pudval) do { *(pudptr) = (pudval); } while (0)
+#endif
+
+#define PGD_T_LOG2	(__builtin_ffs(sizeof(pgd_t)) - 1)
+#define PMD_T_LOG2	(__builtin_ffs(sizeof(pmd_t)) - 1)
+#define PTE_T_LOG2	(__builtin_ffs(sizeof(pte_t)) - 1)
+
+extern pgd_t swapper_pg_dir[];
+extern pgd_t invalid_pg_dir[];
+
+/*
+ * The following only work if pte_present() is true.
+ * Undefined behaviour if not..
+ */
+static inline int pte_write(pte_t pte)	{ return pte_val(pte) & _PAGE_WRITE; }
+static inline int pte_young(pte_t pte)	{ return pte_val(pte) & _PAGE_ACCESSED; }
+static inline int pte_dirty(pte_t pte)	{ return pte_val(pte) & _PAGE_MODIFIED; }
+
+static inline pte_t pte_mkold(pte_t pte)
+{
+	pte_val(pte) &= ~_PAGE_ACCESSED;
+	return pte;
+}
+
+static inline pte_t pte_mkyoung(pte_t pte)
+{
+	pte_val(pte) |= _PAGE_ACCESSED;
+	return pte;
+}
+
+static inline pte_t pte_mkclean(pte_t pte)
+{
+	pte_val(pte) &= ~(_PAGE_DIRTY | _PAGE_MODIFIED);
+	return pte;
+}
+
+static inline pte_t pte_mkdirty(pte_t pte)
+{
+	pte_val(pte) |= (_PAGE_DIRTY | _PAGE_MODIFIED);
+	return pte;
+}
+
+static inline pte_t pte_mkwrite(pte_t pte)
+{
+	pte_val(pte) |= (_PAGE_WRITE | _PAGE_DIRTY);
+	return pte;
+}
+
+static inline pte_t pte_wrprotect(pte_t pte)
+{
+	pte_val(pte) &= ~(_PAGE_WRITE | _PAGE_DIRTY);
+	return pte;
+}
+
+static inline int pte_huge(pte_t pte)	{ return pte_val(pte) & _PAGE_HUGE; }
+
+static inline pte_t pte_mkhuge(pte_t pte)
+{
+	pte_val(pte) |= _PAGE_HUGE;
+	return pte;
+}
+
+#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL)
+static inline int pte_special(pte_t pte)	{ return pte_val(pte) & _PAGE_SPECIAL; }
+static inline pte_t pte_mkspecial(pte_t pte)	{ pte_val(pte) |= _PAGE_SPECIAL; return pte; }
+#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
+
+#define pte_accessible pte_accessible
+static inline unsigned long pte_accessible(struct mm_struct *mm, pte_t a)
+{
+	if (pte_val(a) & _PAGE_PRESENT)
+		return true;
+
+	if ((pte_val(a) & _PAGE_PROTNONE) &&
+			mm_tlb_flush_pending(mm))
+		return true;
+
+	return false;
+}
+
+/*
+ * Conversion functions: convert a page and protection to a page entry,
+ * and a page entry and page directory to the page they refer to.
+ */
+#define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
+
+static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
+{
+	return __pte((pte_val(pte) & _PAGE_CHG_MASK) |
+		     (pgprot_val(newprot) & ~_PAGE_CHG_MASK));
+}
+
+extern void __update_tlb(struct vm_area_struct *vma, unsigned long address,
+	pte_t *ptep);
+
+static inline void update_mmu_cache(struct vm_area_struct *vma,
+	unsigned long address, pte_t *ptep)
+{
+	__update_tlb(vma, address, ptep);
+}
+
+static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
+	unsigned long address, pmd_t *pmdp)
+{
+	__update_tlb(vma, address, (pte_t *)pmdp);
+}
+
+#define kern_addr_valid(addr)	(1)
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+
+/* We don't have hardware dirty/accessed bits, generic_pmdp_establish is fine.*/
+#define pmdp_establish generic_pmdp_establish
+
+#define has_transparent_hugepage has_transparent_hugepage
+extern int has_transparent_hugepage(void);
+
+static inline int pmd_trans_huge(pmd_t pmd)
+{
+	return !!(pmd_val(pmd) & _PAGE_HUGE);
+}
+
+static inline pmd_t pmd_mkhuge(pmd_t pmd)
+{
+	pmd_val(pmd) = (pmd_val(pmd) & ~(_PAGE_GLOBAL)) |
+		((pmd_val(pmd) & _PAGE_GLOBAL) << (_PAGE_HGLOBAL_SHIFT - _PAGE_GLOBAL_SHIFT));
+	pmd_val(pmd) |= _PAGE_HUGE;
+
+	return pmd;
+}
+
+extern void set_pmd_at(struct mm_struct *mm, unsigned long addr,
+		       pmd_t *pmdp, pmd_t pmd);
+
+#define pmd_write pmd_write
+static inline int pmd_write(pmd_t pmd)
+{
+	return !!(pmd_val(pmd) & _PAGE_WRITE);
+}
+
+static inline pmd_t pmd_mkwrite(pmd_t pmd)
+{
+	pmd_val(pmd) |= (_PAGE_WRITE | _PAGE_DIRTY);
+	return pmd;
+}
+
+static inline pmd_t pmd_wrprotect(pmd_t pmd)
+{
+	pmd_val(pmd) &= ~(_PAGE_WRITE | _PAGE_DIRTY);
+	return pmd;
+}
+
+static inline int pmd_dirty(pmd_t pmd)
+{
+	return !!(pmd_val(pmd) & _PAGE_MODIFIED);
+}
+
+static inline pmd_t pmd_mkclean(pmd_t pmd)
+{
+	pmd_val(pmd) &= ~(_PAGE_DIRTY | _PAGE_MODIFIED);
+	return pmd;
+}
+
+static inline pmd_t pmd_mkdirty(pmd_t pmd)
+{
+	pmd_val(pmd) |= (_PAGE_DIRTY | _PAGE_MODIFIED);
+	return pmd;
+}
+
+static inline int pmd_young(pmd_t pmd)
+{
+	return !!(pmd_val(pmd) & _PAGE_ACCESSED);
+}
+
+static inline pmd_t pmd_mkold(pmd_t pmd)
+{
+	pmd_val(pmd) &= ~_PAGE_ACCESSED;
+	return pmd;
+}
+
+static inline pmd_t pmd_mkyoung(pmd_t pmd)
+{
+	pmd_val(pmd) |= _PAGE_ACCESSED;
+	return pmd;
+}
+
+/* Extern to avoid header file madness */
+extern pmd_t mk_pmd(struct page *page, pgprot_t prot);
+
+static inline unsigned long pmd_pfn(pmd_t pmd)
+{
+	return (pmd_val(pmd) & _PFN_MASK) >> _PFN_SHIFT;
+}
+
+static inline struct page *pmd_page(pmd_t pmd)
+{
+	if (pmd_trans_huge(pmd))
+		return pfn_to_page(pmd_pfn(pmd));
+
+	return pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT);
+}
+
+static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
+{
+	pmd_val(pmd) = (pmd_val(pmd) & _HPAGE_CHG_MASK) |
+				(pgprot_val(newprot) & ~_HPAGE_CHG_MASK);
+	return pmd;
+}
+
+static inline pmd_t pmd_mkinvalid(pmd_t pmd)
+{
+	pmd_val(pmd) &= ~(_PAGE_PRESENT | _PAGE_VALID | _PAGE_DIRTY | _PAGE_PROTNONE);
+
+	return pmd;
+}
+
+/*
+ * The generic version pmdp_huge_get_and_clear uses a version of pmd_clear() with a
+ * different prototype.
+ */
+#define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
+static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
+					    unsigned long address, pmd_t *pmdp)
+{
+	pmd_t old = *pmdp;
+
+	pmd_clear(pmdp);
+
+	return old;
+}
+
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+/*
+ * We provide our own get_unmapped area to cope with the virtual aliasing
+ * constraints placed on us by the cache architecture.
+ */
+#define HAVE_ARCH_UNMAPPED_AREA
+#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* _ASM_PGTABLE_H */
diff --git a/arch/loongarch/include/asm/shmparam.h b/arch/loongarch/include/asm/shmparam.h
new file mode 100644
index 000000000000..2b9f6ffc3a81
--- /dev/null
+++ b/arch/loongarch/include/asm/shmparam.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_SHMPARAM_H
+#define _ASM_SHMPARAM_H
+
+#define __ARCH_FORCE_SHMLBA	1
+
+#define	SHMLBA	SZ_64K		 /* attach addr a multiple of this */
+
+#endif /* _ASM_SHMPARAM_H */
diff --git a/arch/loongarch/include/asm/sparsemem.h b/arch/loongarch/include/asm/sparsemem.h
new file mode 100644
index 000000000000..700be7122547
--- /dev/null
+++ b/arch/loongarch/include/asm/sparsemem.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LOONGARCH_SPARSEMEM_H
+#define _LOONGARCH_SPARSEMEM_H
+
+#ifdef CONFIG_SPARSEMEM
+
+/*
+ * SECTION_SIZE_BITS		2^N: how big each section will be
+ * MAX_PHYSMEM_BITS		2^N: how much memory we can have in that space
+ */
+#define SECTION_SIZE_BITS	29 /* 2^29 = Largest Huge Page Size */
+#define MAX_PHYSMEM_BITS	48
+
+#endif /* CONFIG_SPARSEMEM */
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+int memory_add_physaddr_to_nid(u64 addr);
+#define memory_add_physaddr_to_nid memory_add_physaddr_to_nid
+#endif
+
+#endif /* _LOONGARCH_SPARSEMEM_H */
diff --git a/arch/loongarch/include/asm/tlb.h b/arch/loongarch/include/asm/tlb.h
new file mode 100644
index 000000000000..f3e77d3881d6
--- /dev/null
+++ b/arch/loongarch/include/asm/tlb.h
@@ -0,0 +1,216 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#ifndef __ASM_TLB_H
+#define __ASM_TLB_H
+
+#include <linux/mm_types.h>
+#include <asm/cpu-features.h>
+#include <asm/loongarch.h>
+
+/*
+ * TLB Invalidate Flush
+ */
+static inline void tlbclr(void)
+{
+	__asm__ __volatile__("tlbclr");
+}
+
+static inline void tlbflush(void)
+{
+	__asm__ __volatile__("tlbflush");
+}
+
+/*
+ * TLB R/W operations.
+ */
+static inline void tlb_probe(void)
+{
+	__asm__ __volatile__("tlbsrch");
+}
+
+static inline void tlb_read(void)
+{
+	__asm__ __volatile__("tlbrd");
+}
+
+static inline void tlb_write_indexed(void)
+{
+	__asm__ __volatile__("tlbwr");
+}
+
+static inline void tlb_write_random(void)
+{
+	__asm__ __volatile__("tlbfill");
+}
+
+/*
+ * Guest TLB Invalidate Flush
+ */
+static inline void guest_tlbflush(void)
+{
+	__asm__ __volatile__(
+		".word 0x6482401\n\t");
+}
+
+/*
+ * Guest TLB R/W operations.
+ */
+static inline void guest_tlb_probe(void)
+{
+	__asm__ __volatile__(
+		".word 0x6482801\n\t");
+}
+
+static inline void guest_tlb_read(void)
+{
+	__asm__ __volatile__(
+		".word 0x6482c01\n\t");
+}
+
+static inline void guest_tlb_write_indexed(void)
+{
+	__asm__ __volatile__(
+		".word 0x6483001\n\t");
+}
+
+static inline void guest_tlb_write_random(void)
+{
+	__asm__ __volatile__(
+		".word 0x6483401\n\t");
+}
+
+enum invtlb_ops {
+	/* Invalid all tlb */
+	INVTLB_ALL = 0x0,
+	/* Invalid current tlb */
+	INVTLB_CURRENT_ALL = 0x1,
+	/* Invalid all global=1 lines in current tlb */
+	INVTLB_CURRENT_GTRUE = 0x2,
+	/* Invalid all global=0 lines in current tlb */
+	INVTLB_CURRENT_GFALSE = 0x3,
+	/* Invalid global=0 and matched asid lines in current tlb */
+	INVTLB_GFALSE_AND_ASID = 0x4,
+	/* Invalid addr with global=0 and matched asid in current tlb */
+	INVTLB_ADDR_GFALSE_AND_ASID = 0x5,
+	/* Invalid addr with global=1 or matched asid in current tlb */
+	INVTLB_ADDR_GTRUE_OR_ASID = 0x6,
+	/* Invalid matched gid in guest tlb */
+	INVGTLB_GID = 0x9,
+	/* Invalid global=1, matched gid in guest tlb */
+	INVGTLB_GID_GTRUE = 0xa,
+	/* Invalid global=0, matched gid in guest tlb */
+	INVGTLB_GID_GFALSE = 0xb,
+	/* Invalid global=0, matched gid and asid in guest tlb */
+	INVGTLB_GID_GFALSE_ASID = 0xc,
+	/* Invalid global=0 , matched gid, asid and addr in guest tlb */
+	INVGTLB_GID_GFALSE_ASID_ADDR = 0xd,
+	/* Invalid global=1 , matched gid, asid and addr in guest tlb */
+	INVGTLB_GID_GTRUE_ASID_ADDR = 0xe,
+	/* Invalid all gid gva-->gpa guest tlb */
+	INVGTLB_ALLGID_GVA_TO_GPA = 0x10,
+	/* Invalid all gid gpa-->hpa tlb */
+	INVTLB_ALLGID_GPA_TO_HPA = 0x11,
+	/* Invalid all gid tlb, including  gva-->gpa and gpa-->hpa */
+	INVTLB_ALLGID = 0x12,
+	/* Invalid matched gid gva-->gpa guest tlb */
+	INVGTLB_GID_GVA_TO_GPA = 0x13,
+	/* Invalid matched gid gpa-->hpa tlb */
+	INVTLB_GID_GPA_TO_HPA = 0x14,
+	/* Invalid matched gid tlb,including gva-->gpa and gpa-->hpa */
+	INVTLB_GID_ALL = 0x15,
+	/* Invalid matched gid and addr gpa-->hpa tlb */
+	INVTLB_GID_ADDR = 0x16,
+};
+
+/*
+ * invtlb op info addr
+ * (0x1 << 26) | (0x24 << 20) | (0x13 << 15) |
+ * (addr << 10) | (info << 5) | op
+ */
+static inline void invtlb(u32 op, u32 info, u64 addr)
+{
+	__asm__ __volatile__(
+		"parse_r addr,%0\n\t"
+		"parse_r info,%1\n\t"
+		".word ((0x6498000) | (addr << 10) | (info << 5) | %2)\n\t"
+		:
+		: "r"(addr), "r"(info), "i"(op)
+		:
+		);
+}
+
+static inline void invtlb_addr(u32 op, u32 info, u64 addr)
+{
+	__asm__ __volatile__(
+		"parse_r addr,%0\n\t"
+		".word ((0x6498000) | (addr << 10) | (0 << 5) | %1)\n\t"
+		:
+		: "r"(addr), "i"(op)
+		:
+		);
+}
+
+static inline void invtlb_info(u32 op, u32 info, u64 addr)
+{
+	__asm__ __volatile__(
+		"parse_r info,%0\n\t"
+		".word ((0x6498000) | (0 << 10) | (info << 5) | %1)\n\t"
+		:
+		: "r"(info), "i"(op)
+		:
+		);
+}
+
+static inline void invtlb_all(u32 op, u32 info, u64 addr)
+{
+	__asm__ __volatile__(
+		".word ((0x6498000) | (0 << 10) | (0 << 5) | %0)\n\t"
+		:
+		: "i"(op)
+		:
+		);
+}
+
+/*
+ * LoongArch doesn't need any special per-pte or per-vma handling, except
+ * we need to flush cache for area to be unmapped.
+ */
+#define tlb_start_vma(tlb, vma)					\
+	do {							\
+		if (!(tlb)->fullmm)				\
+			flush_cache_range(vma, vma->vm_start, vma->vm_end); \
+	}  while (0)
+#define tlb_end_vma(tlb, vma) do { } while (0)
+#define __tlb_remove_tlb_entry(tlb, ptep, address) do { } while (0)
+
+static void tlb_flush(struct mmu_gather *tlb);
+
+#define tlb_flush tlb_flush
+#include <asm-generic/tlb.h>
+
+static inline void tlb_flush(struct mmu_gather *tlb)
+{
+	struct vm_area_struct vma;
+
+	vma.vm_mm = tlb->mm;
+	vma.vm_flags = 0;
+	if (tlb->fullmm) {
+		flush_tlb_mm(tlb->mm);
+		return;
+	}
+
+	flush_tlb_range(&vma, tlb->start, tlb->end);
+}
+
+extern void handle_tlb_load(void);
+extern void handle_tlb_store(void);
+extern void handle_tlb_modify(void);
+extern void handle_tlb_refill(void);
+extern void handle_tlb_protect(void);
+
+extern void dump_tlb_all(void);
+extern void dump_tlb_regs(void);
+
+#endif /* __ASM_TLB_H */
diff --git a/arch/loongarch/include/asm/tlbflush.h b/arch/loongarch/include/asm/tlbflush.h
new file mode 100644
index 000000000000..a5672367d966
--- /dev/null
+++ b/arch/loongarch/include/asm/tlbflush.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#ifndef __ASM_TLBFLUSH_H
+#define __ASM_TLBFLUSH_H
+
+#include <linux/mm.h>
+
+/*
+ * TLB flushing:
+ *
+ *  - flush_tlb_all() flushes all processes TLB entries
+ *  - flush_tlb_mm(mm) flushes the specified mm context TLB entries
+ *  - flush_tlb_page(vma, vmaddr) flushes one page
+ *  - flush_tlb_range(vma, start, end) flushes a range of pages
+ *  - flush_tlb_kernel_range(start, end) flushes a range of kernel pages
+ */
+extern void local_flush_tlb_all(void);
+extern void local_flush_tlb_mm(struct mm_struct *mm);
+extern void local_flush_tlb_range(struct vm_area_struct *vma,
+	unsigned long start, unsigned long end);
+extern void local_flush_tlb_kernel_range(unsigned long start,
+	unsigned long end);
+extern void local_flush_tlb_page(struct vm_area_struct *vma,
+	unsigned long page);
+extern void local_flush_tlb_one(unsigned long vaddr);
+
+#define flush_tlb_all()			local_flush_tlb_all()
+#define flush_tlb_mm(mm)		local_flush_tlb_mm(mm)
+#define flush_tlb_range(vma, vmaddr, end)	local_flush_tlb_range(vma, vmaddr, end)
+#define flush_tlb_kernel_range(vmaddr, end)	local_flush_tlb_kernel_range(vmaddr, end)
+#define flush_tlb_page(vma, page)	local_flush_tlb_page(vma, page)
+#define flush_tlb_one(vaddr)		local_flush_tlb_one(vaddr)
+
+#endif /* __ASM_TLBFLUSH_H */
diff --git a/arch/loongarch/include/asm/vmalloc.h b/arch/loongarch/include/asm/vmalloc.h
new file mode 100644
index 000000000000..965a0d41ac2d
--- /dev/null
+++ b/arch/loongarch/include/asm/vmalloc.h
@@ -0,0 +1,4 @@
+#ifndef _ASM_LOONGARCH_VMALLOC_H
+#define _ASM_LOONGARCH_VMALLOC_H
+
+#endif /* _ASM_LOONGARCH_VMALLOC_H */
diff --git a/arch/loongarch/mm/cache.c b/arch/loongarch/mm/cache.c
new file mode 100644
index 000000000000..fb94bb4aedc7
--- /dev/null
+++ b/arch/loongarch/mm/cache.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ *
+ * Derived from MIPS:
+ * Copyright (C) 1994 - 2003, 06, 07 by Ralf Baechle (ralf@xxxxxxxxxxxxxx)
+ * Copyright (C) 2007 MIPS Technologies, Inc.
+ */
+#include <linux/export.h>
+#include <linux/fcntl.h>
+#include <linux/fs.h>
+#include <linux/highmem.h>
+#include <linux/kernel.h>
+#include <linux/linkage.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/syscalls.h>
+
+#include <asm/cacheflush.h>
+#include <asm/cpu.h>
+#include <asm/cpu-features.h>
+#include <asm/dma.h>
+#include <asm/loongarch.h>
+#include <asm/processor.h>
+#include <asm/setup.h>
+
+/*
+ * LoongArch maintains ICache/DCache coherency by hardware,
+ * we just need "ibar" to avoid instruction hazard here.
+ */
+void local_flush_icache_range(unsigned long start, unsigned long end)
+{
+	asm volatile ("\tibar 0\n"::);
+}
+
+void __update_cache(unsigned long address, pte_t pte)
+{
+	unsigned long pfn;
+	struct page *page;
+
+	pfn = pte_pfn(pte);
+	if (unlikely(!pfn_valid(pfn)))
+		return;
+	page = pfn_to_page(pfn);
+	if (Page_dcache_dirty(page))
+		ClearPageDcacheDirty(page);
+}
+
+void cache_error_setup(void)
+{
+	extern char __weak except_vec_cex;
+	set_merr_handler(0x0, &except_vec_cex, 0x80);
+}
+
+static unsigned long icache_size __read_mostly;
+static unsigned long dcache_size __read_mostly;
+static unsigned long vcache_size __read_mostly;
+static unsigned long scache_size __read_mostly;
+
+static char *way_string[] = { NULL, "direct mapped", "2-way",
+	"3-way", "4-way", "5-way", "6-way", "7-way", "8-way",
+	"9-way", "10-way", "11-way", "12-way",
+	"13-way", "14-way", "15-way", "16-way",
+};
+
+static void probe_pcache(void)
+{
+	struct cpuinfo_loongarch *c = &current_cpu_data;
+	unsigned int lsize, sets, ways;
+	unsigned int config;
+
+	config = read_cpucfg(LOONGARCH_CPUCFG17);
+	lsize = 1 << ((config & CPUCFG17_L1I_SIZE_M) >> CPUCFG17_L1I_SIZE);
+	sets  = 1 << ((config & CPUCFG17_L1I_SETS_M) >> CPUCFG17_L1I_SETS);
+	ways  = ((config & CPUCFG17_L1I_WAYS_M) >> CPUCFG17_L1I_WAYS) + 1;
+
+	c->icache.linesz = lsize;
+	c->icache.sets = sets;
+	c->icache.ways = ways;
+	icache_size = sets * ways * lsize;
+	c->icache.waysize = icache_size / c->icache.ways;
+
+	config = read_cpucfg(LOONGARCH_CPUCFG18);
+	lsize = 1 << ((config & CPUCFG18_L1D_SIZE_M) >> CPUCFG18_L1D_SIZE);
+	sets  = 1 << ((config & CPUCFG18_L1D_SETS_M) >> CPUCFG18_L1D_SETS);
+	ways  = ((config & CPUCFG18_L1D_WAYS_M) >> CPUCFG18_L1D_WAYS) + 1;
+
+	c->dcache.linesz = lsize;
+	c->dcache.sets = sets;
+	c->dcache.ways = ways;
+	dcache_size = sets * ways * lsize;
+	c->dcache.waysize = dcache_size / c->dcache.ways;
+
+	c->options |= LOONGARCH_CPU_PREFETCH;
+
+	pr_info("Primary instruction cache %ldkB, %s, %s, linesize %d bytes.\n",
+		icache_size >> 10, way_string[c->icache.ways], "VIPT", c->icache.linesz);
+
+	pr_info("Primary data cache %ldkB, %s, %s, %s, linesize %d bytes\n",
+		dcache_size >> 10, way_string[c->dcache.ways], "VIPT", "no aliases", c->dcache.linesz);
+}
+
+static void probe_vcache(void)
+{
+	struct cpuinfo_loongarch *c = &current_cpu_data;
+	unsigned int lsize, sets, ways;
+	unsigned int config;
+
+	config = read_cpucfg(LOONGARCH_CPUCFG19);
+	lsize = 1 << ((config & CPUCFG19_L2_SIZE_M) >> CPUCFG19_L2_SIZE);
+	sets  = 1 << ((config & CPUCFG19_L2_SETS_M) >> CPUCFG19_L2_SETS);
+	ways  = ((config & CPUCFG19_L2_WAYS_M) >> CPUCFG19_L2_WAYS) + 1;
+
+	c->vcache.linesz = lsize;
+	c->vcache.sets = sets;
+	c->vcache.ways = ways;
+	vcache_size = lsize * sets * ways;
+	c->vcache.waysize = vcache_size / c->vcache.ways;
+
+	pr_info("Unified victim cache %ldkB %s, linesize %d bytes.\n",
+		vcache_size >> 10, way_string[c->vcache.ways], c->vcache.linesz);
+}
+
+static void probe_scache(void)
+{
+	struct cpuinfo_loongarch *c = &current_cpu_data;
+	unsigned int lsize, sets, ways;
+	unsigned int config;
+
+	config = read_cpucfg(LOONGARCH_CPUCFG20);
+	lsize = 1 << ((config & CPUCFG20_L3_SIZE_M) >> CPUCFG20_L3_SIZE);
+	sets  = 1 << ((config & CPUCFG20_L3_SETS_M) >> CPUCFG20_L3_SETS);
+	ways  = ((config & CPUCFG20_L3_WAYS_M) >> CPUCFG20_L3_WAYS) + 1;
+
+	c->scache.linesz = lsize;
+	c->scache.sets = sets;
+	c->scache.ways = ways;
+	/* 4 cores. scaches are shared */
+	scache_size = lsize * sets * ways;
+	c->scache.waysize = scache_size / c->scache.ways;
+
+	pr_info("Unified secondary cache %ldkB %s, linesize %d bytes.\n",
+		scache_size >> 10, way_string[c->scache.ways], c->scache.linesz);
+}
+
+void cpu_cache_init(void)
+{
+	probe_pcache();
+	probe_vcache();
+	probe_scache();
+
+	shm_align_mask = PAGE_SIZE - 1;
+}
diff --git a/arch/loongarch/mm/extable.c b/arch/loongarch/mm/extable.c
new file mode 100644
index 000000000000..7b367a8dd7e0
--- /dev/null
+++ b/arch/loongarch/mm/extable.c
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#include <linux/extable.h>
+#include <linux/spinlock.h>
+#include <asm/branch.h>
+#include <linux/uaccess.h>
+
+int fixup_exception(struct pt_regs *regs)
+{
+	const struct exception_table_entry *fixup;
+
+	fixup = search_exception_tables(exception_epc(regs));
+	if (fixup) {
+		regs->csr_epc = fixup->fixup;
+
+		return 1;
+	}
+
+	return 0;
+}
diff --git a/arch/loongarch/mm/fault.c b/arch/loongarch/mm/fault.c
new file mode 100644
index 000000000000..78de5bfd0721
--- /dev/null
+++ b/arch/loongarch/mm/fault.c
@@ -0,0 +1,248 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ *
+ * Derived from MIPS:
+ * Copyright (C) 1995 - 2000 by Ralf Baechle
+ */
+#include <linux/context_tracking.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/entry-common.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/ratelimit.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/kdebug.h>
+#include <linux/kprobes.h>
+#include <linux/perf_event.h>
+#include <linux/uaccess.h>
+
+#include <asm/branch.h>
+#include <asm/mmu_context.h>
+#include <asm/ptrace.h>
+
+int show_unhandled_signals = 1;
+
+/*
+ * This routine handles page faults.  It determines the address,
+ * and the problem, and then passes it off to one of the appropriate
+ * routines.
+ */
+static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write,
+	unsigned long address)
+{
+	int si_code;
+	const int field = sizeof(unsigned long) * 2;
+	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
+	struct task_struct *tsk = current;
+	struct mm_struct *mm = tsk->mm;
+	struct vm_area_struct *vma = NULL;
+	vm_fault_t fault;
+
+	static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 10);
+
+	si_code = SEGV_MAPERR;
+
+	if (user_mode(regs) && (address & __UA_LIMIT))
+		goto bad_area_nosemaphore;
+
+	/*
+	 * We fault-in kernel-space virtual memory on-demand. The
+	 * 'reference' page table is init_mm.pgd.
+	 *
+	 * NOTE! We MUST NOT take any locks for this case. We may
+	 * be in an interrupt or a critical region, and should
+	 * only copy the information from the master page table,
+	 * nothing more.
+	 */
+	if (unlikely(address >= VMALLOC_START && address <= VMALLOC_END))
+		goto no_context;
+
+	/*
+	 * If we're in an interrupt or have no user
+	 * context, we must not take the fault..
+	 */
+	if (faulthandler_disabled() || !mm)
+		goto bad_area_nosemaphore;
+
+	if (user_mode(regs))
+		flags |= FAULT_FLAG_USER;
+retry:
+	mmap_read_lock(mm);
+	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:
+	si_code = SEGV_ACCERR;
+
+	if (write) {
+		if (!(vma->vm_flags & VM_WRITE))
+			goto bad_area;
+		flags |= FAULT_FLAG_WRITE;
+	} else {
+		if (address == regs->csr_epc && !(vma->vm_flags & VM_EXEC))
+			goto bad_area;
+		if (!(vma->vm_flags & VM_READ) &&
+		    exception_epc(regs) != address)
+			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(vma, address, flags, regs);
+
+	if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
+		return;
+
+	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
+	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) {
+			perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1,
+						  regs, address);
+			tsk->maj_flt++;
+		} else {
+			perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1,
+						  regs, address);
+			tsk->min_flt++;
+		}
+		if (fault & VM_FAULT_RETRY) {
+			flags &= ~FAULT_FLAG_ALLOW_RETRY;
+			flags |= FAULT_FLAG_TRIED;
+
+			/*
+			 * No need to mmap_read_unlock(mm) as we would
+			 * have already released it in __lock_page_or_retry
+			 * in mm/filemap.c.
+			 */
+
+			goto retry;
+		}
+	}
+
+	mmap_read_unlock(mm);
+	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:
+	mmap_read_unlock(mm);
+
+bad_area_nosemaphore:
+	/* User mode accesses just cause a SIGSEGV */
+	if (user_mode(regs)) {
+		tsk->thread.csr_badvaddr = address;
+		tsk->thread.error_code = write;
+		if (show_unhandled_signals &&
+		    unhandled_signal(tsk, SIGSEGV) &&
+		    __ratelimit(&ratelimit_state)) {
+			pr_info("do_page_fault(): sending SIGSEGV to %s for invalid %s %0*lx\n",
+				tsk->comm,
+				write ? "write access to" : "read access from",
+				field, address);
+			pr_info("epc = %0*lx in", field,
+				(unsigned long) regs->csr_epc);
+			print_vma_addr(KERN_CONT " ", regs->csr_epc);
+			pr_cont("\n");
+			pr_info("ra  = %0*lx in", field,
+				(unsigned long) regs->regs[1]);
+			print_vma_addr(KERN_CONT " ", regs->regs[1]);
+			pr_cont("\n");
+		}
+		current->thread.trap_nr = read_csr_excode();
+		force_sig_fault(SIGSEGV, si_code, (void __user *)address);
+		return;
+	}
+
+no_context:
+	/* Are we prepared to handle this kernel fault?	 */
+	if (fixup_exception(regs))
+		return;
+
+	/*
+	 * Oops. The kernel tried to access some bad page. We'll have to
+	 * terminate things with extreme prejudice.
+	 */
+	bust_spinlocks(1);
+
+	pr_alert("CPU %d Unable to handle kernel paging request at "
+	       "virtual address %0*lx, epc == %0*lx, ra == %0*lx\n",
+	       raw_smp_processor_id(), field, address, field, regs->csr_epc,
+	       field,  regs->regs[1]);
+	die("Oops", regs);
+
+out_of_memory:
+	/*
+	 * We ran out of memory, call the OOM killer, and return the userspace
+	 * (which will retry the fault, or kill us if we got oom-killed).
+	 */
+	mmap_read_unlock(mm);
+	if (!user_mode(regs))
+		goto no_context;
+	pagefault_out_of_memory();
+
+	return;
+
+do_sigbus:
+	mmap_read_unlock(mm);
+
+	/* Kernel mode? Handle exceptions or die */
+	if (!user_mode(regs))
+		goto no_context;
+
+	/*
+	 * Send a sigbus, regardless of whether we were in kernel
+	 * or user mode.
+	 */
+	current->thread.trap_nr = read_csr_excode();
+	tsk->thread.csr_badvaddr = address;
+	force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address);
+
+	return;
+}
+
+asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
+	unsigned long write, unsigned long address)
+{
+	irqentry_state_t state = irqentry_enter(regs);
+
+	/* Enable interrupt if enabled in parent context */
+	if (likely(regs->csr_prmd & CSR_PRMD_PIE))
+		local_irq_enable();
+
+	__do_page_fault(regs, write, address);
+
+	local_irq_disable();
+
+	irqentry_exit(regs, state);
+}
diff --git a/arch/loongarch/mm/hugetlbpage.c b/arch/loongarch/mm/hugetlbpage.c
new file mode 100644
index 000000000000..f6f56f5e8a08
--- /dev/null
+++ b/arch/loongarch/mm/hugetlbpage.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/pagemap.h>
+#include <linux/err.h>
+#include <linux/sysctl.h>
+#include <asm/mman.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+
+pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
+		      unsigned long addr, unsigned long sz)
+{
+	pgd_t *pgd;
+	p4d_t *p4d;
+	pud_t *pud;
+	pte_t *pte = NULL;
+
+	pgd = pgd_offset(mm, addr);
+	p4d = p4d_alloc(mm, pgd, addr);
+	pud = pud_alloc(mm, p4d, addr);
+	if (pud)
+		pte = (pte_t *)pmd_alloc(mm, pud, addr);
+
+	return pte;
+}
+
+pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr,
+		       unsigned long sz)
+{
+	pgd_t *pgd;
+	p4d_t *p4d;
+	pud_t *pud;
+	pmd_t *pmd = NULL;
+
+	pgd = pgd_offset(mm, addr);
+	if (pgd_present(*pgd)) {
+		p4d = p4d_offset(pgd, addr);
+		if (p4d_present(*p4d)) {
+			pud = pud_offset(p4d, addr);
+			if (pud_present(*pud))
+				pmd = pmd_offset(pud, addr);
+		}
+	}
+	return (pte_t *) pmd;
+}
+
+/*
+ * This function checks for proper alignment of input addr and len parameters.
+ */
+int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
+{
+	if (len & ~HPAGE_MASK)
+		return -EINVAL;
+	if (addr & ~HPAGE_MASK)
+		return -EINVAL;
+	return 0;
+}
+
+int pmd_huge(pmd_t pmd)
+{
+	return (pmd_val(pmd) & _PAGE_HUGE) != 0;
+}
+
+int pud_huge(pud_t pud)
+{
+	return (pud_val(pud) & _PAGE_HUGE) != 0;
+}
+
+uint64_t pmd_to_entrylo(unsigned long pmd_val)
+{
+	uint64_t val;
+	/* PMD as PTE. Must be huge page */
+	if (!pmd_huge(__pmd(pmd_val)))
+		panic("%s", __func__);
+
+	val = pmd_val ^ _PAGE_HUGE;
+	val |= ((val & _PAGE_HGLOBAL) >>
+		(_PAGE_HGLOBAL_SHIFT - _PAGE_GLOBAL_SHIFT));
+
+	return val;
+}
diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c
new file mode 100644
index 000000000000..1e7ce2a2b427
--- /dev/null
+++ b/arch/loongarch/mm/init.c
@@ -0,0 +1,196 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#include <linux/bug.h>
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/smp.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/pagemap.h>
+#include <linux/ptrace.h>
+#include <linux/memblock.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/highmem.h>
+#include <linux/swap.h>
+#include <linux/proc_fs.h>
+#include <linux/pfn.h>
+#include <linux/hardirq.h>
+#include <linux/gfp.h>
+#include <linux/initrd.h>
+#include <linux/mmzone.h>
+
+#include <asm/asm-offsets.h>
+#include <asm/bootinfo.h>
+#include <asm/cpu.h>
+#include <asm/dma.h>
+#include <asm/mmu_context.h>
+#include <asm/sections.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/tlb.h>
+
+/*
+ * We have up to 8 empty zeroed pages so we can map one of the right colour
+ * when needed.	 Since page is never written to after the initialization we
+ * don't have to care about aliases on other CPUs.
+ */
+unsigned long empty_zero_page, zero_page_mask;
+EXPORT_SYMBOL_GPL(empty_zero_page);
+EXPORT_SYMBOL(zero_page_mask);
+
+void setup_zero_pages(void)
+{
+	unsigned int order, i;
+	struct page *page;
+
+	order = 0;
+
+	empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
+	if (!empty_zero_page)
+		panic("Oh boy, that early out of memory?");
+
+	page = virt_to_page((void *)empty_zero_page);
+	split_page(page, order);
+	for (i = 0; i < (1 << order); i++, page++)
+		mark_page_reserved(page);
+
+	zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
+}
+
+void copy_user_highpage(struct page *to, struct page *from,
+	unsigned long vaddr, struct vm_area_struct *vma)
+{
+	void *vfrom, *vto;
+
+	vto = kmap_atomic(to);
+	vfrom = kmap_atomic(from);
+	copy_page(vto, vfrom);
+	kunmap_atomic(vfrom);
+	kunmap_atomic(vto);
+	/* Make sure this page is cleared on other CPU's too before using it */
+	smp_wmb();
+}
+
+void copy_to_user_page(struct vm_area_struct *vma,
+	struct page *page, unsigned long vaddr, void *dst, const void *src,
+	unsigned long len)
+{
+	memcpy(dst, src, len);
+}
+
+void copy_from_user_page(struct vm_area_struct *vma,
+	struct page *page, unsigned long vaddr, void *dst, const void *src,
+	unsigned long len)
+{
+	memcpy(dst, src, len);
+}
+EXPORT_SYMBOL_GPL(copy_from_user_page);
+
+void __init paging_init(void)
+{
+	unsigned long max_zone_pfns[MAX_NR_ZONES];
+
+#ifdef CONFIG_ZONE_DMA
+	max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
+#endif
+#ifdef CONFIG_ZONE_DMA32
+	max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
+#endif
+	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
+
+	free_area_init(max_zone_pfns);
+}
+
+void __init mem_init(void)
+{
+	max_mapnr = max_low_pfn;
+	high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
+
+	memblock_free_all();
+	setup_zero_pages();	/* Setup zeroed pages.  */
+}
+
+void free_init_pages(const char *what, unsigned long begin, unsigned long end)
+{
+	unsigned long pfn;
+
+	for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
+		struct page *page = pfn_to_page(pfn);
+		void *addr = phys_to_virt(PFN_PHYS(pfn));
+
+		memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
+		free_reserved_page(page);
+	}
+	pr_info("Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void free_initrd_mem(unsigned long start, unsigned long end)
+{
+	free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
+			   "initrd");
+}
+#endif
+
+void __ref free_initmem(void)
+{
+	free_initmem_default(POISON_FREE_INITMEM);
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+int arch_add_memory(int nid, u64 start, u64 size, struct mhp_params *params)
+{
+	unsigned long start_pfn = start >> PAGE_SHIFT;
+	unsigned long nr_pages = size >> PAGE_SHIFT;
+	int ret;
+
+	ret = __add_pages(nid, start_pfn, nr_pages, params);
+
+	if (ret)
+		pr_warn("%s: Problem encountered in __add_pages() as ret=%d\n",
+				__func__,  ret);
+
+	return ret;
+}
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
+{
+	unsigned long start_pfn = start >> PAGE_SHIFT;
+	unsigned long nr_pages = size >> PAGE_SHIFT;
+	struct page *page = pfn_to_page(start_pfn);
+
+	/* With altmap the first mapped page is offset from @start */
+	if (altmap)
+		page += vmem_altmap_offset(altmap);
+	__remove_pages(start_pfn, nr_pages, altmap);
+}
+#endif
+#endif
+
+/*
+ * Align swapper_pg_dir in to 64K, allows its address to be loaded
+ * with a single LUI instruction in the TLB handlers.  If we used
+ * __aligned(64K), its size would get rounded up to the alignment
+ * size, and waste space.  So we place it in its own section and align
+ * it in the linker script.
+ */
+pgd_t swapper_pg_dir[_PTRS_PER_PGD] __section(".bss..swapper_pg_dir");
+
+pgd_t invalid_pg_dir[_PTRS_PER_PGD] __page_aligned_bss;
+#ifndef __PAGETABLE_PUD_FOLDED
+pud_t invalid_pud_table[PTRS_PER_PUD] __page_aligned_bss;
+#endif
+#ifndef __PAGETABLE_PMD_FOLDED
+pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned_bss;
+EXPORT_SYMBOL_GPL(invalid_pmd_table);
+#endif
+pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
+EXPORT_SYMBOL(invalid_pte_table);
diff --git a/arch/loongarch/mm/ioremap.c b/arch/loongarch/mm/ioremap.c
new file mode 100644
index 000000000000..4181290d82fc
--- /dev/null
+++ b/arch/loongarch/mm/ioremap.c
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+
+#include <asm/io.h>
+
+void __init __iomem *early_ioremap(u64 phys_addr, unsigned long size)
+{
+	return ((void __iomem *)TO_CAC(phys_addr));
+}
+
+void __init early_iounmap(void __iomem *addr, unsigned long size)
+{
+
+}
+
+void *early_memremap_ro(resource_size_t phys_addr, unsigned long size)
+{
+	return early_memremap(phys_addr, size);
+}
+
+void *early_memremap_prot(resource_size_t phys_addr, unsigned long size,
+		    unsigned long prot_val)
+{
+	return early_memremap(phys_addr, size);
+}
diff --git a/arch/loongarch/mm/maccess.c b/arch/loongarch/mm/maccess.c
new file mode 100644
index 000000000000..58173842c6be
--- /dev/null
+++ b/arch/loongarch/mm/maccess.c
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/uaccess.h>
+#include <linux/kernel.h>
+
+bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
+{
+	/* highest bit set means kernel space */
+	return (unsigned long)unsafe_src >> (BITS_PER_LONG - 1);
+}
diff --git a/arch/loongarch/mm/mmap.c b/arch/loongarch/mm/mmap.c
new file mode 100644
index 000000000000..0365586e57c9
--- /dev/null
+++ b/arch/loongarch/mm/mmap.c
@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#include <linux/compiler.h>
+#include <linux/elf-randomize.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/export.h>
+#include <linux/personality.h>
+#include <linux/random.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/mm.h>
+
+unsigned long shm_align_mask = PAGE_SIZE - 1;	/* Sane caches */
+EXPORT_SYMBOL(shm_align_mask);
+
+#define COLOUR_ALIGN(addr, pgoff)				\
+	((((addr) + shm_align_mask) & ~shm_align_mask) +	\
+	 (((pgoff) << PAGE_SHIFT) & shm_align_mask))
+
+enum mmap_allocation_direction {UP, DOWN};
+
+static unsigned long arch_get_unmapped_area_common(struct file *filp,
+	unsigned long addr0, unsigned long len, unsigned long pgoff,
+	unsigned long flags, enum mmap_allocation_direction dir)
+{
+	struct mm_struct *mm = current->mm;
+	struct vm_area_struct *vma;
+	unsigned long addr = addr0;
+	int do_color_align;
+	struct vm_unmapped_area_info info;
+
+	if (unlikely(len > TASK_SIZE))
+		return -ENOMEM;
+
+	if (flags & MAP_FIXED) {
+		/* Even MAP_FIXED mappings must reside within TASK_SIZE */
+		if (TASK_SIZE - len < addr)
+			return -EINVAL;
+
+		/*
+		 * We do not accept a shared mapping if it would violate
+		 * cache aliasing constraints.
+		 */
+		if ((flags & MAP_SHARED) &&
+		    ((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask))
+			return -EINVAL;
+		return addr;
+	}
+
+	do_color_align = 0;
+	if (filp || (flags & MAP_SHARED))
+		do_color_align = 1;
+
+	/* requesting a specific address */
+	if (addr) {
+		if (do_color_align)
+			addr = COLOUR_ALIGN(addr, pgoff);
+		else
+			addr = PAGE_ALIGN(addr);
+
+		vma = find_vma(mm, addr);
+		if (TASK_SIZE - len >= addr &&
+		    (!vma || addr + len <= vm_start_gap(vma)))
+			return addr;
+	}
+
+	info.length = len;
+	info.align_mask = do_color_align ? (PAGE_MASK & shm_align_mask) : 0;
+	info.align_offset = pgoff << PAGE_SHIFT;
+
+	if (dir == DOWN) {
+		info.flags = VM_UNMAPPED_AREA_TOPDOWN;
+		info.low_limit = PAGE_SIZE;
+		info.high_limit = mm->mmap_base;
+		addr = vm_unmapped_area(&info);
+
+		if (!(addr & ~PAGE_MASK))
+			return addr;
+
+		/*
+		 * A failed mmap() very likely causes application failure,
+		 * so fall back to the bottom-up function here. This scenario
+		 * can happen with large stack limits and large mmap()
+		 * allocations.
+		 */
+	}
+
+	info.flags = 0;
+	info.low_limit = mm->mmap_base;
+	info.high_limit = TASK_SIZE;
+	return vm_unmapped_area(&info);
+}
+
+unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr0,
+	unsigned long len, unsigned long pgoff, unsigned long flags)
+{
+	return arch_get_unmapped_area_common(filp,
+			addr0, len, pgoff, flags, UP);
+}
+
+/*
+ * There is no need to export this but sched.h declares the function as
+ * extern so making it static here results in an error.
+ */
+unsigned long arch_get_unmapped_area_topdown(struct file *filp,
+	unsigned long addr0, unsigned long len, unsigned long pgoff,
+	unsigned long flags)
+{
+	return arch_get_unmapped_area_common(filp,
+			addr0, len, pgoff, flags, DOWN);
+}
+
+int __virt_addr_valid(volatile void *kaddr)
+{
+	unsigned long vaddr = (unsigned long)kaddr;
+
+	if ((vaddr < PAGE_OFFSET) || (vaddr >= vm_map_base))
+		return 0;
+
+	return pfn_valid(PFN_DOWN(virt_to_phys(kaddr)));
+}
+EXPORT_SYMBOL_GPL(__virt_addr_valid);
diff --git a/arch/loongarch/mm/page.S b/arch/loongarch/mm/page.S
new file mode 100644
index 000000000000..254b5c7f802b
--- /dev/null
+++ b/arch/loongarch/mm/page.S
@@ -0,0 +1,84 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#include <linux/linkage.h>
+#include <asm/asm.h>
+#include <asm/export.h>
+#include <asm/page.h>
+#include <asm/regdef.h>
+
+	.align 5
+SYM_FUNC_START(clear_page)
+	lu12i.w  t0, 1 << (PAGE_SHIFT - 12)
+	add.d    t0, t0, a0
+1:
+	st.d     zero, a0, 0
+	st.d     zero, a0, 8
+	st.d     zero, a0, 16
+	st.d     zero, a0, 24
+	st.d     zero, a0, 32
+	st.d     zero, a0, 40
+	st.d     zero, a0, 48
+	st.d     zero, a0, 56
+	addi.d   a0,   a0, 128
+	st.d     zero, a0, -64
+	st.d     zero, a0, -56
+	st.d     zero, a0, -48
+	st.d     zero, a0, -40
+	st.d     zero, a0, -32
+	st.d     zero, a0, -24
+	st.d     zero, a0, -16
+	st.d     zero, a0, -8
+	bne      t0,   a0, 1b
+
+	jirl     $r0, ra, 0
+SYM_FUNC_END(clear_page)
+EXPORT_SYMBOL(clear_page)
+
+.align 5
+SYM_FUNC_START(copy_page)
+	lu12i.w  t8, 1 << (PAGE_SHIFT - 12)
+	add.d    t8, t8, a0
+1:
+	ld.d     t0, a1,  0
+	ld.d     t1, a1,  8
+	ld.d     t2, a1,  16
+	ld.d     t3, a1,  24
+	ld.d     t4, a1,  32
+	ld.d     t5, a1,  40
+	ld.d     t6, a1,  48
+	ld.d     t7, a1,  56
+
+	st.d     t0, a0,  0
+	st.d     t1, a0,  8
+	ld.d     t0, a1,  64
+	ld.d     t1, a1,  72
+	st.d     t2, a0,  16
+	st.d     t3, a0,  24
+	ld.d     t2, a1,  80
+	ld.d     t3, a1,  88
+	st.d     t4, a0,  32
+	st.d     t5, a0,  40
+	ld.d     t4, a1,  96
+	ld.d     t5, a1,  104
+	st.d     t6, a0,  48
+	st.d     t7, a0,  56
+	ld.d     t6, a1,  112
+	ld.d     t7, a1,  120
+	addi.d   a0, a0,  128
+	addi.d   a1, a1,  128
+
+	st.d     t0, a0,  -64
+	st.d     t1, a0,  -56
+	st.d     t2, a0,  -48
+	st.d     t3, a0,  -40
+	st.d     t4, a0,  -32
+	st.d     t5, a0,  -24
+	st.d     t6, a0,  -16
+	st.d     t7, a0,  -8
+
+	bne      t8, a0, 1b
+	jirl     $r0, ra, 0
+SYM_FUNC_END(copy_page)
+EXPORT_SYMBOL(copy_page)
diff --git a/arch/loongarch/mm/pgtable.c b/arch/loongarch/mm/pgtable.c
new file mode 100644
index 000000000000..9bb3b6b5c319
--- /dev/null
+++ b/arch/loongarch/mm/pgtable.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+#include <asm/tlbflush.h>
+
+pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+	pgd_t *ret, *init;
+
+	ret = (pgd_t *) __get_free_pages(GFP_KERNEL, PGD_ORDER);
+	if (ret) {
+		init = pgd_offset(&init_mm, 0UL);
+		pgd_init((unsigned long)ret);
+		memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
+		       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pgd_alloc);
+
+void pgd_init(unsigned long page)
+{
+	unsigned long *p, *end;
+	unsigned long entry;
+
+#if !defined(__PAGETABLE_PUD_FOLDED)
+	entry = (unsigned long)invalid_pud_table;
+#elif !defined(__PAGETABLE_PMD_FOLDED)
+	entry = (unsigned long)invalid_pmd_table;
+#else
+	entry = (unsigned long)invalid_pte_table;
+#endif
+
+	p = (unsigned long *) page;
+	end = p + PTRS_PER_PGD;
+
+	do {
+		p[0] = entry;
+		p[1] = entry;
+		p[2] = entry;
+		p[3] = entry;
+		p[4] = entry;
+		p += 8;
+		p[-3] = entry;
+		p[-2] = entry;
+		p[-1] = entry;
+	} while (p != end);
+}
+
+#ifndef __PAGETABLE_PMD_FOLDED
+void pmd_init(unsigned long addr, unsigned long pagetable)
+{
+	unsigned long *p, *end;
+
+	p = (unsigned long *) addr;
+	end = p + PTRS_PER_PMD;
+
+	do {
+		p[0] = pagetable;
+		p[1] = pagetable;
+		p[2] = pagetable;
+		p[3] = pagetable;
+		p[4] = pagetable;
+		p += 8;
+		p[-3] = pagetable;
+		p[-2] = pagetable;
+		p[-1] = pagetable;
+	} while (p != end);
+}
+EXPORT_SYMBOL_GPL(pmd_init);
+#endif
+
+#ifndef __PAGETABLE_PUD_FOLDED
+void pud_init(unsigned long addr, unsigned long pagetable)
+{
+	unsigned long *p, *end;
+
+	p = (unsigned long *)addr;
+	end = p + PTRS_PER_PUD;
+
+	do {
+		p[0] = pagetable;
+		p[1] = pagetable;
+		p[2] = pagetable;
+		p[3] = pagetable;
+		p[4] = pagetable;
+		p += 8;
+		p[-3] = pagetable;
+		p[-2] = pagetable;
+		p[-1] = pagetable;
+	} while (p != end);
+}
+#endif
+
+pmd_t mk_pmd(struct page *page, pgprot_t prot)
+{
+	pmd_t pmd;
+
+	pmd_val(pmd) = (page_to_pfn(page) << _PFN_SHIFT) | pgprot_val(prot);
+
+	return pmd;
+}
+
+void set_pmd_at(struct mm_struct *mm, unsigned long addr,
+		pmd_t *pmdp, pmd_t pmd)
+{
+	*pmdp = pmd;
+	flush_tlb_all();
+}
+
+void __init pagetable_init(void)
+{
+	pgd_t *pgd_base;
+
+	/* Initialize the entire pgd.  */
+	pgd_init((unsigned long)swapper_pg_dir);
+	pgd_init((unsigned long)invalid_pg_dir);
+#ifndef __PAGETABLE_PUD_FOLDED
+	pud_init((unsigned long)invalid_pud_table, (unsigned long)invalid_pmd_table);
+#endif
+#ifndef __PAGETABLE_PMD_FOLDED
+	pmd_init((unsigned long)invalid_pmd_table, (unsigned long)invalid_pte_table);
+#endif
+	pgd_base = swapper_pg_dir;
+}
diff --git a/arch/loongarch/mm/tlb.c b/arch/loongarch/mm/tlb.c
new file mode 100644
index 000000000000..2af695e045d1
--- /dev/null
+++ b/arch/loongarch/mm/tlb.c
@@ -0,0 +1,287 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/smp.h>
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/export.h>
+
+#include <asm/cpu.h>
+#include <asm/bootinfo.h>
+#include <asm/mmu_context.h>
+#include <asm/pgtable.h>
+#include <asm/tlb.h>
+
+void local_flush_tlb_all(void)
+{
+	invtlb_all(INVTLB_CURRENT_ALL, 0, 0);
+}
+EXPORT_SYMBOL(local_flush_tlb_all);
+
+/*
+ * All entries common to a mm share an asid. To effectively flush
+ * these entries, we just bump the asid.
+ */
+void local_flush_tlb_mm(struct mm_struct *mm)
+{
+	int cpu;
+
+	preempt_disable();
+
+	cpu = smp_processor_id();
+
+	if (asid_valid(mm, cpu))
+		drop_mmu_context(mm, cpu);
+	else
+		cpumask_clear_cpu(cpu, mm_cpumask(mm));
+
+	preempt_enable();
+}
+
+void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
+	unsigned long end)
+{
+	struct mm_struct *mm = vma->vm_mm;
+	int cpu = smp_processor_id();
+
+	if (asid_valid(mm, cpu)) {
+		unsigned long size, flags;
+
+		local_irq_save(flags);
+		start = round_down(start, PAGE_SIZE << 1);
+		end = round_up(end, PAGE_SIZE << 1);
+		size = (end - start) >> (PAGE_SHIFT + 1);
+		if (size <= (current_cpu_data.tlbsizestlbsets ?
+			     current_cpu_data.tlbsize / 8 :
+			     current_cpu_data.tlbsize / 2)) {
+			int asid = cpu_asid(cpu, mm);
+
+			while (start < end) {
+				invtlb(INVTLB_ADDR_GFALSE_AND_ASID, asid, start);
+				start += (PAGE_SIZE << 1);
+			}
+		} else {
+			drop_mmu_context(mm, cpu);
+		}
+		local_irq_restore(flags);
+	} else {
+		cpumask_clear_cpu(cpu, mm_cpumask(mm));
+	}
+}
+
+void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
+{
+	unsigned long size, flags;
+
+	local_irq_save(flags);
+	size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
+	size = (size + 1) >> 1;
+	if (size <= (current_cpu_data.tlbsizestlbsets ?
+		     current_cpu_data.tlbsize / 8 :
+		     current_cpu_data.tlbsize / 2)) {
+
+		start &= (PAGE_MASK << 1);
+		end += ((PAGE_SIZE << 1) - 1);
+		end &= (PAGE_MASK << 1);
+
+		while (start < end) {
+			invtlb_addr(INVTLB_ADDR_GTRUE_OR_ASID, 0, start);
+			start += (PAGE_SIZE << 1);
+		}
+	} else {
+		local_flush_tlb_all();
+	}
+	local_irq_restore(flags);
+}
+
+void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
+{
+	int cpu = smp_processor_id();
+
+	if (asid_valid(vma->vm_mm, cpu)) {
+		int newpid;
+
+		newpid = cpu_asid(cpu, vma->vm_mm);
+		page &= (PAGE_MASK << 1);
+		invtlb(INVTLB_ADDR_GFALSE_AND_ASID, newpid, page);
+	} else {
+		cpumask_clear_cpu(cpu, mm_cpumask(vma->vm_mm));
+	}
+}
+
+/*
+ * This one is only used for pages with the global bit set so we don't care
+ * much about the ASID.
+ */
+void local_flush_tlb_one(unsigned long page)
+{
+	page &= (PAGE_MASK << 1);
+	invtlb_addr(INVTLB_ADDR_GTRUE_OR_ASID, 0, page);
+}
+
+static void __update_hugetlb(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
+{
+	int idx;
+	unsigned long lo;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	address &= (PAGE_MASK << 1);
+	write_csr_entryhi(address);
+	tlb_probe();
+	idx = read_csr_tlbidx();
+	write_csr_pagesize(PS_HUGE_SIZE);
+	lo = pmd_to_entrylo(pte_val(*ptep));
+	write_csr_entrylo0(lo);
+	write_csr_entrylo1(lo + (HPAGE_SIZE >> 1));
+
+	if (idx < 0)
+		tlb_write_random();
+	else
+		tlb_write_indexed();
+	write_csr_pagesize(PS_DEFAULT_SIZE);
+
+	local_irq_restore(flags);
+}
+
+void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
+{
+	int idx;
+	unsigned long flags;
+
+	/*
+	 * Handle debugger faulting in for debugee.
+	 */
+	if (current->active_mm != vma->vm_mm)
+		return;
+
+	if (pte_val(*ptep) & _PAGE_HUGE)
+		return __update_hugetlb(vma, address, ptep);
+
+	local_irq_save(flags);
+
+	if ((unsigned long)ptep & sizeof(pte_t))
+		ptep--;
+
+	address &= (PAGE_MASK << 1);
+	write_csr_entryhi(address);
+	tlb_probe();
+	idx = read_csr_tlbidx();
+	write_csr_pagesize(PS_DEFAULT_SIZE);
+	write_csr_entrylo0(pte_val(*ptep++));
+	write_csr_entrylo1(pte_val(*ptep));
+	if (idx < 0)
+		tlb_write_random();
+	else
+		tlb_write_indexed();
+
+	local_irq_restore(flags);
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+
+int has_transparent_hugepage(void)
+{
+	static unsigned int size = -1;
+
+	if (size == -1) {	/* first call comes during __init */
+		unsigned long flags;
+
+		local_irq_save(flags);
+		write_csr_pagesize(PS_HUGE_SIZE);
+		size = read_csr_pagesize();
+		write_csr_pagesize(PS_DEFAULT_SIZE);
+		local_irq_restore(flags);
+	}
+	return size == PS_HUGE_SIZE;
+}
+
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE  */
+
+static void setup_pw(void)
+{
+	unsigned long pgd_i, pgd_w;
+#ifndef __PAGETABLE_PMD_FOLDED
+	unsigned long pmd_i, pmd_w;
+#endif
+	unsigned long pte_i, pte_w;
+
+	pgd_i = PGDIR_SHIFT;  /* 1st level PGD */
+#ifndef __PAGETABLE_PMD_FOLDED
+	pgd_w = PGDIR_SHIFT - PMD_SHIFT + PGD_ORDER;
+	pmd_i = PMD_SHIFT;    /* 2nd level PMD */
+	pmd_w = PMD_SHIFT - PAGE_SHIFT;
+#else
+	pgd_w = PGDIR_SHIFT - PAGE_SHIFT + PGD_ORDER;
+#endif
+	pte_i  = PAGE_SHIFT;    /* 3rd level PTE */
+	pte_w  = PAGE_SHIFT - 3;
+
+#ifndef __PAGETABLE_PMD_FOLDED
+	csr_writeq(pte_i | pte_w << 5 | pmd_i << 10 | pmd_w << 15, LOONGARCH_CSR_PWCTL0);
+	csr_writeq(pgd_i | pgd_w << 6, LOONGARCH_CSR_PWCTL1);
+#else
+	csr_writeq(pte_i | pte_w << 5, LOONGARCH_CSR_PWCTL0);
+	csr_writeq(pgd_i | pgd_w << 6, LOONGARCH_CSR_PWCTL1);
+#endif
+	csr_writeq((long)swapper_pg_dir, LOONGARCH_CSR_PGDH);
+}
+
+static void output_pgtable_bits_defines(void)
+{
+#define pr_define(fmt, ...)					\
+	pr_debug("#define " fmt, ##__VA_ARGS__)
+
+	pr_debug("#include <asm/asm.h>\n");
+	pr_debug("#include <asm/regdef.h>\n");
+	pr_debug("\n");
+
+	pr_define("_PAGE_VALID_SHIFT %d\n", _PAGE_VALID_SHIFT);
+	pr_define("_PAGE_DIRTY_SHIFT %d\n", _PAGE_DIRTY_SHIFT);
+	pr_define("_PAGE_HUGE_SHIFT %d\n", _PAGE_HUGE_SHIFT);
+	pr_define("_PAGE_GLOBAL_SHIFT %d\n", _PAGE_GLOBAL_SHIFT);
+	pr_define("_PAGE_PRESENT_SHIFT %d\n", _PAGE_PRESENT_SHIFT);
+	pr_define("_PAGE_WRITE_SHIFT %d\n", _PAGE_WRITE_SHIFT);
+	pr_define("_PAGE_NO_READ_SHIFT %d\n", _PAGE_NO_READ_SHIFT);
+	pr_define("_PAGE_NO_EXEC_SHIFT %d\n", _PAGE_NO_EXEC_SHIFT);
+	pr_define("_PFN_SHIFT %d\n", _PFN_SHIFT);
+	pr_debug("\n");
+}
+
+void setup_tlb_handler(void)
+{
+	static int run_once = 0;
+
+	setup_pw();
+	output_pgtable_bits_defines();
+
+	/* The tlb handlers are generated only once */
+	if (!run_once) {
+		memcpy((void *)tlbrentry, handle_tlb_refill, 0x80);
+		local_flush_icache_range(tlbrentry, tlbrentry + 0x80);
+		set_handler(EXCCODE_TLBI * VECSIZE, handle_tlb_load, VECSIZE);
+		set_handler(EXCCODE_TLBL * VECSIZE, handle_tlb_load, VECSIZE);
+		set_handler(EXCCODE_TLBS * VECSIZE, handle_tlb_store, VECSIZE);
+		set_handler(EXCCODE_TLBM * VECSIZE, handle_tlb_modify, VECSIZE);
+		set_handler(EXCCODE_TLBPE * VECSIZE, handle_tlb_protect, VECSIZE);
+		set_handler(EXCCODE_TLBRI * VECSIZE, handle_tlb_protect, VECSIZE);
+		set_handler(EXCCODE_TLBXI * VECSIZE, handle_tlb_protect, VECSIZE);
+		run_once++;
+	}
+}
+
+void tlb_init(void)
+{
+	write_csr_pagesize(PS_DEFAULT_SIZE);
+	write_csr_stlbpgsize(PS_DEFAULT_SIZE);
+
+	if (read_csr_pagesize() != PS_DEFAULT_SIZE)
+		panic("MMU doesn't support PAGE_SIZE=0x%lx", PAGE_SIZE);
+
+	setup_tlb_handler();
+	local_flush_tlb_all();
+}
diff --git a/arch/loongarch/mm/tlbex.S b/arch/loongarch/mm/tlbex.S
new file mode 100644
index 000000000000..6ff03662811a
--- /dev/null
+++ b/arch/loongarch/mm/tlbex.S
@@ -0,0 +1,468 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+#include <asm/asm.h>
+#include <asm/export.h>
+#include <asm/loongarch.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/regdef.h>
+#include <asm/stackframe.h>
+
+	.macro tlb_do_page_fault, write
+	SYM_FUNC_START(tlb_do_page_fault_\write)
+	SAVE_ALL
+	csrrd	a2, LOONGARCH_CSR_BADV
+	KMODE
+	move	a0, sp
+	REG_S	a2, sp, PT_BVADDR
+	li.w	a1, \write
+	la.abs	t0, do_page_fault
+	jirl    ra, t0, 0
+	RESTORE_ALL_AND_RET
+	SYM_FUNC_END(tlb_do_page_fault_\write)
+	.endm
+
+SYM_FUNC_START(handle_tlb_protect)
+	csrwr	t0, EXCEPTION_KS0
+	csrwr	t1, EXCEPTION_KS1
+SYM_FUNC_END(handle_tlb_protect)
+	/* Go through */
+	tlb_do_page_fault 0
+	tlb_do_page_fault 1
+
+SYM_FUNC_START(handle_tlb_load)
+	csrwr	t0, EXCEPTION_KS0
+	csrwr	t1, EXCEPTION_KS1
+	csrwr	ra, EXCEPTION_KS2
+
+	/*
+	 * The vmalloc handling is not in the hotpath.
+	 */
+	csrrd	t0, LOONGARCH_CSR_BADV
+	blt	t0, $r0, vmalloc_load
+	csrrd	t1, LOONGARCH_CSR_PGDL
+
+vmalloc_done_load:
+	/* Get PGD offset in bytes */
+	srli.d	t0, t0, PGDIR_SHIFT
+	andi	t0, t0, (PTRS_PER_PGD - 1)
+	slli.d	t0, t0, 3
+	add.d	t1, t1, t0
+#if CONFIG_PGTABLE_LEVELS > 3
+	csrrd	t0, LOONGARCH_CSR_BADV
+	ld.d t1, t1, 0
+	srli.d	t0, t0, PUD_SHIFT
+	andi	t0, t0, (PTRS_PER_PUD - 1)
+	slli.d	t0, t0, 3
+	add.d	t1, t1, t0
+#endif
+#if CONFIG_PGTABLE_LEVELS > 2
+	csrrd	t0, LOONGARCH_CSR_BADV
+	ld.d	t1, t1, 0
+	srli.d	t0, t0, PMD_SHIFT
+	andi	t0, t0, (PTRS_PER_PMD - 1)
+	slli.d	t0, t0, 3
+	add.d	t1, t1, t0
+#endif
+	ld.d	ra, t1, 0
+
+	/*
+	 * For huge tlb entries, pmde doesn't contain an address but
+	 * instead contains the tlb pte. Check the PAGE_HUGE bit and
+	 * see if we need to jump to huge tlb processing.
+	 */
+	andi	t0, ra, _PAGE_HUGE
+	bne	t0, $r0, tlb_huge_update_load
+
+	csrrd	t0, LOONGARCH_CSR_BADV
+	srli.d	t0, t0, (PAGE_SHIFT + PTE_ORDER)
+	andi	t0, t0, (PTRS_PER_PTE - 1)
+	slli.d	t0, t0, _PTE_T_LOG2
+	add.d	t1, ra, t0
+
+	ld.d	t0, t1, 0
+	tlbsrch
+
+	srli.d	ra, t0, _PAGE_PRESENT_SHIFT
+	andi	ra, ra, 1
+	beq	ra, $r0, nopage_tlb_load
+
+	ori	t0, t0, _PAGE_VALID
+	st.d	t0, t1, 0
+	ori	t1, t1, 8
+	xori	t1, t1, 8
+	ld.d	t0, t1, 0
+	ld.d	t1, t1, 8
+	csrwr	t0, LOONGARCH_CSR_TLBELO0
+	csrwr	t1, LOONGARCH_CSR_TLBELO1
+	tlbwr
+leave_load:
+	csrrd	t0, EXCEPTION_KS0
+	csrrd	t1, EXCEPTION_KS1
+	csrrd	ra, EXCEPTION_KS2
+	ertn
+#ifdef CONFIG_64BIT
+vmalloc_load:
+	la.abs	t1, swapper_pg_dir
+	b	vmalloc_done_load
+#endif
+
+	/*
+	 * This is the entry point when build_tlbchange_handler_head
+	 * spots a huge page.
+	 */
+tlb_huge_update_load:
+	ld.d	t0, t1, 0
+	srli.d	ra, t0, _PAGE_PRESENT_SHIFT
+	andi	ra, ra, 1
+	beq	ra, $r0, nopage_tlb_load
+	tlbsrch
+
+	ori	t0, t0, _PAGE_VALID
+	st.d	t0, t1, 0
+	addu16i.d	t1, $r0, -(CSR_TLBIDX_EHINV >> 16)
+	addi.d	ra, t1, 0
+	csrxchg	ra, t1, LOONGARCH_CSR_TLBIDX
+	tlbwr
+
+	csrxchg	$r0, t1, LOONGARCH_CSR_TLBIDX
+
+	/*
+	 * A huge PTE describes an area the size of the
+	 * configured huge page size. This is twice the
+	 * of the large TLB entry size we intend to use.
+	 * A TLB entry half the size of the configured
+	 * huge page size is configured into entrylo0
+	 * and entrylo1 to cover the contiguous huge PTE
+	 * address space.
+	 */
+	/* Huge page: Move Global bit */
+	xori	t0, t0, _PAGE_HUGE
+	lu12i.w	t1, _PAGE_HGLOBAL >> 12
+	and	t1, t0, t1
+	srli.d	t1, t1, (_PAGE_HGLOBAL_SHIFT - _PAGE_GLOBAL_SHIFT)
+	or	t0, t0, t1
+
+	addi.d	ra, t0, 0
+	csrwr	t0, LOONGARCH_CSR_TLBELO0
+	addi.d	t0, ra, 0
+
+	/* Convert to entrylo1 */
+	addi.d	t1, $r0, 1
+	slli.d	t1, t1, (HPAGE_SHIFT - 1)
+	add.d	t0, t0, t1
+	csrwr	t0, LOONGARCH_CSR_TLBELO1
+
+	/* Set huge page tlb entry size */
+	addu16i.d	t0, $r0, (PS_MASK >> 16)
+	addu16i.d	t1, $r0, (PS_HUGE_SIZE << (PS_SHIFT - 16))
+	csrxchg		t1, t0, LOONGARCH_CSR_TLBIDX
+
+	tlbfill
+
+	addu16i.d	t0, $r0, (PS_MASK >> 16)
+	addu16i.d	t1, $r0, (PS_DEFAULT_SIZE << (PS_SHIFT - 16))
+	csrxchg		t1, t0, LOONGARCH_CSR_TLBIDX
+
+nopage_tlb_load:
+	csrrd	ra, EXCEPTION_KS2
+	la.abs	t0, tlb_do_page_fault_0
+	jirl	$r0, t0, 0
+SYM_FUNC_END(handle_tlb_load)
+
+SYM_FUNC_START(handle_tlb_store)
+	csrwr	t0, EXCEPTION_KS0
+	csrwr	t1, EXCEPTION_KS1
+	csrwr	ra, EXCEPTION_KS2
+
+	/*
+	 * The vmalloc handling is not in the hotpath.
+	 */
+	csrrd	t0, LOONGARCH_CSR_BADV
+	blt	t0, $r0, vmalloc_store
+	csrrd	t1, LOONGARCH_CSR_PGDL
+
+vmalloc_done_store:
+	/* Get PGD offset in bytes */
+	srli.d	t0, t0, PGDIR_SHIFT
+	andi	t0, t0, (PTRS_PER_PGD - 1)
+	slli.d	t0, t0, 3
+	add.d	t1, t1, t0
+
+#if CONFIG_PGTABLE_LEVELS > 3
+	csrrd	t0, LOONGARCH_CSR_BADV
+	ld.d t1, t1, 0
+	srli.d	t0, t0, PUD_SHIFT
+	andi	t0, t0, (PTRS_PER_PUD - 1)
+	slli.d	t0, t0, 3
+	add.d	t1, t1, t0
+#endif
+#if CONFIG_PGTABLE_LEVELS > 2
+	csrrd	t0, LOONGARCH_CSR_BADV
+	ld.d	t1, t1, 0
+	srli.d	t0, t0, PMD_SHIFT
+	andi	t0, t0, (PTRS_PER_PMD - 1)
+	slli.d	t0, t0, 3
+	add.d	t1, t1, t0
+#endif
+	ld.d	ra, t1, 0
+
+	/*
+	 * For huge tlb entries, pmde doesn't contain an address but
+	 * instead contains the tlb pte. Check the PAGE_HUGE bit and
+	 * see if we need to jump to huge tlb processing.
+	 */
+	andi	t0, ra, _PAGE_HUGE
+	bne	t0, $r0, tlb_huge_update_store
+
+	csrrd	t0, LOONGARCH_CSR_BADV
+	srli.d	t0, t0, (PAGE_SHIFT + PTE_ORDER)
+	andi	t0, t0, (PTRS_PER_PTE - 1)
+	slli.d	t0, t0, _PTE_T_LOG2
+	add.d	t1, ra, t0
+
+	ld.d	t0, t1, 0
+	tlbsrch
+
+	srli.d	ra, t0, _PAGE_PRESENT_SHIFT
+	andi	ra, ra, ((_PAGE_PRESENT | _PAGE_WRITE) >> _PAGE_PRESENT_SHIFT)
+	xori	ra, ra, ((_PAGE_PRESENT | _PAGE_WRITE) >> _PAGE_PRESENT_SHIFT)
+	bne	ra, $r0, nopage_tlb_store
+
+	ori	t0, t0, (_PAGE_VALID | _PAGE_DIRTY | _PAGE_MODIFIED)
+	st.d	t0, t1, 0
+
+	ori	t1, t1, 8
+	xori	t1, t1, 8
+	ld.d	t0, t1, 0
+	ld.d	t1, t1, 8
+	csrwr	t0, LOONGARCH_CSR_TLBELO0
+	csrwr	t1, LOONGARCH_CSR_TLBELO1
+	tlbwr
+leave_store:
+	csrrd	t0, EXCEPTION_KS0
+	csrrd	t1, EXCEPTION_KS1
+	csrrd	ra, EXCEPTION_KS2
+	ertn
+#ifdef CONFIG_64BIT
+vmalloc_store:
+	la.abs	t1, swapper_pg_dir
+	b	vmalloc_done_store
+#endif
+
+	/*
+	 * This is the entry point when build_tlbchange_handler_head
+	 * spots a huge page.
+	 */
+tlb_huge_update_store:
+	ld.d	t0, t1, 0
+	srli.d	ra, t0, _PAGE_PRESENT_SHIFT
+	andi	ra, ra, ((_PAGE_PRESENT | _PAGE_WRITE) >> _PAGE_PRESENT_SHIFT)
+	xori	ra, ra, ((_PAGE_PRESENT | _PAGE_WRITE) >> _PAGE_PRESENT_SHIFT)
+	bne	ra, $r0, nopage_tlb_store
+
+	tlbsrch
+	ori	t0, t0, (_PAGE_VALID | _PAGE_DIRTY | _PAGE_MODIFIED)
+
+	st.d	t0, t1, 0
+	addu16i.d	t1, $r0, -(CSR_TLBIDX_EHINV >> 16)
+	addi.d	ra, t1, 0
+	csrxchg	ra, t1, LOONGARCH_CSR_TLBIDX
+	tlbwr
+
+	csrxchg	$r0, t1, LOONGARCH_CSR_TLBIDX
+	/*
+	 * A huge PTE describes an area the size of the
+	 * configured huge page size. This is twice the
+	 * of the large TLB entry size we intend to use.
+	 * A TLB entry half the size of the configured
+	 * huge page size is configured into entrylo0
+	 * and entrylo1 to cover the contiguous huge PTE
+	 * address space.
+	 */
+	/* Huge page: Move Global bit */
+	xori	t0, t0, _PAGE_HUGE
+	lu12i.w	t1, _PAGE_HGLOBAL >> 12
+	and	t1, t0, t1
+	srli.d	t1, t1, (_PAGE_HGLOBAL_SHIFT - _PAGE_GLOBAL_SHIFT)
+	or	t0, t0, t1
+
+	addi.d	ra, t0, 0
+	csrwr	t0, LOONGARCH_CSR_TLBELO0
+	addi.d	t0, ra, 0
+
+	/* Convert to entrylo1 */
+	addi.d	t1, $r0, 1
+	slli.d	t1, t1, (HPAGE_SHIFT - 1)
+	add.d	t0, t0, t1
+	csrwr	t0, LOONGARCH_CSR_TLBELO1
+
+	/* Set huge page tlb entry size */
+	addu16i.d	t0, $r0, (PS_MASK >> 16)
+	addu16i.d	t1, $r0, (PS_HUGE_SIZE << (PS_SHIFT - 16))
+	csrxchg		t1, t0, LOONGARCH_CSR_TLBIDX
+
+	tlbfill
+
+	/* Reset default page size */
+	addu16i.d	t0, $r0, (PS_MASK >> 16)
+	addu16i.d	t1, $r0, (PS_DEFAULT_SIZE << (PS_SHIFT - 16))
+	csrxchg		t1, t0, LOONGARCH_CSR_TLBIDX
+
+nopage_tlb_store:
+	csrrd	ra, EXCEPTION_KS2
+	la.abs	t0, tlb_do_page_fault_1
+	jirl	$r0, t0, 0
+SYM_FUNC_END(handle_tlb_store)
+
+SYM_FUNC_START(handle_tlb_modify)
+	csrwr	t0, EXCEPTION_KS0
+	csrwr	t1, EXCEPTION_KS1
+	csrwr	ra, EXCEPTION_KS2
+
+	/*
+	 * The vmalloc handling is not in the hotpath.
+	 */
+	csrrd	t0, LOONGARCH_CSR_BADV
+	blt	t0, $r0, vmalloc_modify
+	csrrd	t1, LOONGARCH_CSR_PGDL
+
+vmalloc_done_modify:
+	/* Get PGD offset in bytes */
+	srli.d	t0, t0, PGDIR_SHIFT
+	andi	t0, t0, (PTRS_PER_PGD - 1)
+	slli.d	t0, t0, 3
+	add.d	t1, t1, t0
+#if CONFIG_PGTABLE_LEVELS > 3
+	csrrd	t0, LOONGARCH_CSR_BADV
+	ld.d t1, t1, 0
+	srli.d	t0, t0, PUD_SHIFT
+	andi	t0, t0, (PTRS_PER_PUD - 1)
+	slli.d	t0, t0, 3
+	add.d	t1, t1, t0
+#endif
+#if CONFIG_PGTABLE_LEVELS > 2
+	csrrd	t0, LOONGARCH_CSR_BADV
+	ld.d	t1, t1, 0
+	srli.d	t0, t0, PMD_SHIFT
+	andi	t0, t0, (PTRS_PER_PMD - 1)
+	slli.d	t0, t0, 3
+	add.d	t1, t1, t0
+#endif
+	ld.d	ra, t1, 0
+
+	/*
+	 * For huge tlb entries, pmde doesn't contain an address but
+	 * instead contains the tlb pte. Check the PAGE_HUGE bit and
+	 * see if we need to jump to huge tlb processing.
+	 */
+	andi	t0, ra, _PAGE_HUGE
+	bne	t0, $r0, tlb_huge_update_modify
+
+	csrrd	t0, LOONGARCH_CSR_BADV
+	srli.d	t0, t0, (PAGE_SHIFT + PTE_ORDER)
+	andi	t0, t0, (PTRS_PER_PTE - 1)
+	slli.d	t0, t0, _PTE_T_LOG2
+	add.d	t1, ra, t0
+
+	ld.d	t0, t1, 0
+	tlbsrch
+
+	srli.d	ra, t0, _PAGE_WRITE_SHIFT
+	andi	ra, ra, 1
+	beq	ra, $r0, nopage_tlb_modify
+
+	ori	t0, t0, (_PAGE_VALID | _PAGE_DIRTY | _PAGE_MODIFIED)
+	st.d	t0, t1, 0
+	ori	t1, t1, 8
+	xori	t1, t1, 8
+	ld.d	t0, t1, 0
+	ld.d	t1, t1, 8
+	csrwr	t0, LOONGARCH_CSR_TLBELO0
+	csrwr	t1, LOONGARCH_CSR_TLBELO1
+	tlbwr
+leave_modify:
+	csrrd	t0, EXCEPTION_KS0
+	csrrd	t1, EXCEPTION_KS1
+	csrrd	ra, EXCEPTION_KS2
+	ertn
+#ifdef CONFIG_64BIT
+vmalloc_modify:
+	la.abs  t1, swapper_pg_dir
+	b	vmalloc_done_modify
+#endif
+
+	/*
+	 * This is the entry point when
+	 * build_tlbchange_handler_head spots a huge page.
+	 */
+tlb_huge_update_modify:
+	ld.d	t0, t1, 0
+
+	srli.d	ra, t0, _PAGE_WRITE_SHIFT
+	andi	ra, ra, 1
+	beq	ra, $r0, nopage_tlb_modify
+
+	tlbsrch
+	ori	t0, t0, (_PAGE_VALID | _PAGE_DIRTY | _PAGE_MODIFIED)
+
+	st.d	t0, t1, 0
+	/*
+	 * A huge PTE describes an area the size of the
+	 * configured huge page size. This is twice the
+	 * of the large TLB entry size we intend to use.
+	 * A TLB entry half the size of the configured
+	 * huge page size is configured into entrylo0
+	 * and entrylo1 to cover the contiguous huge PTE
+	 * address space.
+	 */
+	/* Huge page: Move Global bit */
+	xori	t0, t0, _PAGE_HUGE
+	lu12i.w	t1, _PAGE_HGLOBAL >> 12
+	and	t1, t0, t1
+	srli.d	t1, t1, (_PAGE_HGLOBAL_SHIFT - _PAGE_GLOBAL_SHIFT)
+	or	t0, t0, t1
+
+	addi.d	ra, t0, 0
+	csrwr	t0, LOONGARCH_CSR_TLBELO0
+	addi.d	t0, ra, 0
+
+	/* Convert to entrylo1 */
+	addi.d	t1, $r0, 1
+	slli.d	t1, t1, (HPAGE_SHIFT - 1)
+	add.d	t0, t0, t1
+	csrwr	t0, LOONGARCH_CSR_TLBELO1
+
+	/* Set huge page tlb entry size */
+	addu16i.d	t0, $r0, (PS_MASK >> 16)
+	addu16i.d	t1, $r0, (PS_HUGE_SIZE << (PS_SHIFT - 16))
+	csrxchg	t1, t0, LOONGARCH_CSR_TLBIDX
+
+	tlbwr
+
+	/* Reset default page size */
+	addu16i.d	t0, $r0, (PS_MASK >> 16)
+	addu16i.d	t1, $r0, (PS_DEFAULT_SIZE << (PS_SHIFT - 16))
+	csrxchg	t1, t0, LOONGARCH_CSR_TLBIDX
+
+nopage_tlb_modify:
+	csrrd	ra, EXCEPTION_KS2
+	la.abs	t0, tlb_do_page_fault_1
+	jirl	$r0, t0, 0
+SYM_FUNC_END(handle_tlb_modify)
+
+SYM_FUNC_START(handle_tlb_refill)
+	csrwr	t0, LOONGARCH_CSR_TLBRSAVE
+	csrrd	t0, LOONGARCH_CSR_PGD
+	lddir	t0, t0, 3
+#if CONFIG_PGTABLE_LEVELS > 2
+	lddir	t0, t0, 1
+#endif
+	ldpte	t0, 0
+	ldpte	t0, 1
+	tlbfill
+	csrrd	t0, LOONGARCH_CSR_TLBRSAVE
+	ertn
+SYM_FUNC_END(handle_tlb_refill)
-- 
2.27.0