Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/csky/include/asm/Kbuild b/arch/csky/include/asm/Kbuild
new file mode 100644
index 0000000..4d4754e
--- /dev/null
+++ b/arch/csky/include/asm/Kbuild
@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: GPL-2.0
+generic-y += asm-offsets.h
+generic-y += bugs.h
+generic-y += compat.h
+generic-y += current.h
+generic-y += delay.h
+generic-y += device.h
+generic-y += div64.h
+generic-y += dma.h
+generic-y += dma-contiguous.h
+generic-y += dma-mapping.h
+generic-y += emergency-restart.h
+generic-y += exec.h
+generic-y += fb.h
+generic-y += futex.h
+generic-y += gpio.h
+generic-y += hardirq.h
+generic-y += hw_irq.h
+generic-y += irq.h
+generic-y += irq_regs.h
+generic-y += irq_work.h
+generic-y += kdebug.h
+generic-y += kmap_types.h
+generic-y += kprobes.h
+generic-y += kvm_para.h
+generic-y += linkage.h
+generic-y += local.h
+generic-y += local64.h
+generic-y += mm-arch-hooks.h
+generic-y += mmiowb.h
+generic-y += module.h
+generic-y += pci.h
+generic-y += percpu.h
+generic-y += preempt.h
+generic-y += qrwlock.h
+generic-y += sections.h
+generic-y += serial.h
+generic-y += timex.h
+generic-y += topology.h
+generic-y += trace_clock.h
+generic-y += unaligned.h
+generic-y += user.h
+generic-y += vga.h
+generic-y += vmlinux.lds.h
+generic-y += word-at-a-time.h
+generic-y += xor.h
diff --git a/arch/csky/include/asm/addrspace.h b/arch/csky/include/asm/addrspace.h
new file mode 100644
index 0000000..d1c2ede
--- /dev/null
+++ b/arch/csky/include/asm/addrspace.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_ADDRSPACE_H
+#define __ASM_CSKY_ADDRSPACE_H
+
+#define KSEG0		0x80000000ul
+#define KSEG0ADDR(a)	(((unsigned long)a & 0x1fffffff) | KSEG0)
+
+#endif /* __ASM_CSKY_ADDRSPACE_H */
diff --git a/arch/csky/include/asm/asid.h b/arch/csky/include/asm/asid.h
new file mode 100644
index 0000000..ac08b0f
--- /dev/null
+++ b/arch/csky/include/asm/asid.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_ASM_ASID_H
+#define __ASM_ASM_ASID_H
+
+#include <linux/atomic.h>
+#include <linux/compiler.h>
+#include <linux/cpumask.h>
+#include <linux/percpu.h>
+#include <linux/spinlock.h>
+
+struct asid_info
+{
+	atomic64_t	generation;
+	unsigned long	*map;
+	atomic64_t __percpu	*active;
+	u64 __percpu		*reserved;
+	u32			bits;
+	/* Lock protecting the structure */
+	raw_spinlock_t		lock;
+	/* Which CPU requires context flush on next call */
+	cpumask_t		flush_pending;
+	/* Number of ASID allocated by context (shift value) */
+	unsigned int		ctxt_shift;
+	/* Callback to locally flush the context. */
+	void			(*flush_cpu_ctxt_cb)(void);
+};
+
+#define NUM_ASIDS(info)			(1UL << ((info)->bits))
+#define NUM_CTXT_ASIDS(info)		(NUM_ASIDS(info) >> (info)->ctxt_shift)
+
+#define active_asid(info, cpu)	*per_cpu_ptr((info)->active, cpu)
+
+void asid_new_context(struct asid_info *info, atomic64_t *pasid,
+		      unsigned int cpu, struct mm_struct *mm);
+
+/*
+ * Check the ASID is still valid for the context. If not generate a new ASID.
+ *
+ * @pasid: Pointer to the current ASID batch
+ * @cpu: current CPU ID. Must have been acquired throught get_cpu()
+ */
+static inline void asid_check_context(struct asid_info *info,
+				      atomic64_t *pasid, unsigned int cpu,
+				      struct mm_struct *mm)
+{
+	u64 asid, old_active_asid;
+
+	asid = atomic64_read(pasid);
+
+	/*
+	 * The memory ordering here is subtle.
+	 * If our active_asid is non-zero and the ASID matches the current
+	 * generation, then we update the active_asid entry with a relaxed
+	 * cmpxchg. Racing with a concurrent rollover means that either:
+	 *
+	 * - We get a zero back from the cmpxchg and end up waiting on the
+	 *   lock. Taking the lock synchronises with the rollover and so
+	 *   we are forced to see the updated generation.
+	 *
+	 * - We get a valid ASID back from the cmpxchg, which means the
+	 *   relaxed xchg in flush_context will treat us as reserved
+	 *   because atomic RmWs are totally ordered for a given location.
+	 */
+	old_active_asid = atomic64_read(&active_asid(info, cpu));
+	if (old_active_asid &&
+	    !((asid ^ atomic64_read(&info->generation)) >> info->bits) &&
+	    atomic64_cmpxchg_relaxed(&active_asid(info, cpu),
+				     old_active_asid, asid))
+		return;
+
+	asid_new_context(info, pasid, cpu, mm);
+}
+
+int asid_allocator_init(struct asid_info *info,
+			u32 bits, unsigned int asid_per_ctxt,
+			void (*flush_cpu_ctxt_cb)(void));
+
+#endif
diff --git a/arch/csky/include/asm/atomic.h b/arch/csky/include/asm/atomic.h
new file mode 100644
index 0000000..e369d73
--- /dev/null
+++ b/arch/csky/include/asm/atomic.h
@@ -0,0 +1,212 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_ATOMIC_H
+#define __ASM_CSKY_ATOMIC_H
+
+#include <linux/version.h>
+#include <asm/cmpxchg.h>
+#include <asm/barrier.h>
+
+#ifdef CONFIG_CPU_HAS_LDSTEX
+
+#define __atomic_add_unless __atomic_add_unless
+static inline int __atomic_add_unless(atomic_t *v, int a, int u)
+{
+	unsigned long tmp, ret;
+
+	smp_mb();
+
+	asm volatile (
+	"1:	ldex.w		%0, (%3) \n"
+	"	mov		%1, %0   \n"
+	"	cmpne		%0, %4   \n"
+	"	bf		2f	 \n"
+	"	add		%0, %2   \n"
+	"	stex.w		%0, (%3) \n"
+	"	bez		%0, 1b   \n"
+	"2:				 \n"
+		: "=&r" (tmp), "=&r" (ret)
+		: "r" (a), "r"(&v->counter), "r"(u)
+		: "memory");
+
+	if (ret != u)
+		smp_mb();
+
+	return ret;
+}
+
+#define ATOMIC_OP(op, c_op)						\
+static inline void atomic_##op(int i, atomic_t *v)			\
+{									\
+	unsigned long tmp;						\
+									\
+	asm volatile (							\
+	"1:	ldex.w		%0, (%2) \n"				\
+	"	" #op "		%0, %1   \n"				\
+	"	stex.w		%0, (%2) \n"				\
+	"	bez		%0, 1b   \n"				\
+		: "=&r" (tmp)						\
+		: "r" (i), "r"(&v->counter)				\
+		: "memory");						\
+}
+
+#define ATOMIC_OP_RETURN(op, c_op)					\
+static inline int atomic_##op##_return(int i, atomic_t *v)		\
+{									\
+	unsigned long tmp, ret;						\
+									\
+	smp_mb();							\
+	asm volatile (							\
+	"1:	ldex.w		%0, (%3) \n"				\
+	"	" #op "		%0, %2   \n"				\
+	"	mov		%1, %0   \n"				\
+	"	stex.w		%0, (%3) \n"				\
+	"	bez		%0, 1b   \n"				\
+		: "=&r" (tmp), "=&r" (ret)				\
+		: "r" (i), "r"(&v->counter)				\
+		: "memory");						\
+	smp_mb();							\
+									\
+	return ret;							\
+}
+
+#define ATOMIC_FETCH_OP(op, c_op)					\
+static inline int atomic_fetch_##op(int i, atomic_t *v)			\
+{									\
+	unsigned long tmp, ret;						\
+									\
+	smp_mb();							\
+	asm volatile (							\
+	"1:	ldex.w		%0, (%3) \n"				\
+	"	mov		%1, %0   \n"				\
+	"	" #op "		%0, %2   \n"				\
+	"	stex.w		%0, (%3) \n"				\
+	"	bez		%0, 1b   \n"				\
+		: "=&r" (tmp), "=&r" (ret)				\
+		: "r" (i), "r"(&v->counter)				\
+		: "memory");						\
+	smp_mb();							\
+									\
+	return ret;							\
+}
+
+#else /* CONFIG_CPU_HAS_LDSTEX */
+
+#include <linux/irqflags.h>
+
+#define __atomic_add_unless __atomic_add_unless
+static inline int __atomic_add_unless(atomic_t *v, int a, int u)
+{
+	unsigned long tmp, ret, flags;
+
+	raw_local_irq_save(flags);
+
+	asm volatile (
+	"	ldw		%0, (%3) \n"
+	"	mov		%1, %0   \n"
+	"	cmpne		%0, %4   \n"
+	"	bf		2f	 \n"
+	"	add		%0, %2   \n"
+	"	stw		%0, (%3) \n"
+	"2:				 \n"
+		: "=&r" (tmp), "=&r" (ret)
+		: "r" (a), "r"(&v->counter), "r"(u)
+		: "memory");
+
+	raw_local_irq_restore(flags);
+
+	return ret;
+}
+
+#define ATOMIC_OP(op, c_op)						\
+static inline void atomic_##op(int i, atomic_t *v)			\
+{									\
+	unsigned long tmp, flags;					\
+									\
+	raw_local_irq_save(flags);					\
+									\
+	asm volatile (							\
+	"	ldw		%0, (%2) \n"				\
+	"	" #op "		%0, %1   \n"				\
+	"	stw		%0, (%2) \n"				\
+		: "=&r" (tmp)						\
+		: "r" (i), "r"(&v->counter)				\
+		: "memory");						\
+									\
+	raw_local_irq_restore(flags);					\
+}
+
+#define ATOMIC_OP_RETURN(op, c_op)					\
+static inline int atomic_##op##_return(int i, atomic_t *v)		\
+{									\
+	unsigned long tmp, ret, flags;					\
+									\
+	raw_local_irq_save(flags);					\
+									\
+	asm volatile (							\
+	"	ldw		%0, (%3) \n"				\
+	"	" #op "		%0, %2   \n"				\
+	"	stw		%0, (%3) \n"				\
+	"	mov		%1, %0   \n"				\
+		: "=&r" (tmp), "=&r" (ret)				\
+		: "r" (i), "r"(&v->counter)				\
+		: "memory");						\
+									\
+	raw_local_irq_restore(flags);					\
+									\
+	return ret;							\
+}
+
+#define ATOMIC_FETCH_OP(op, c_op)					\
+static inline int atomic_fetch_##op(int i, atomic_t *v)			\
+{									\
+	unsigned long tmp, ret, flags;					\
+									\
+	raw_local_irq_save(flags);					\
+									\
+	asm volatile (							\
+	"	ldw		%0, (%3) \n"				\
+	"	mov		%1, %0   \n"				\
+	"	" #op "		%0, %2   \n"				\
+	"	stw		%0, (%3) \n"				\
+		: "=&r" (tmp), "=&r" (ret)				\
+		: "r" (i), "r"(&v->counter)				\
+		: "memory");						\
+									\
+	raw_local_irq_restore(flags);					\
+									\
+	return ret;							\
+}
+
+#endif /* CONFIG_CPU_HAS_LDSTEX */
+
+#define atomic_add_return atomic_add_return
+ATOMIC_OP_RETURN(add, +)
+#define atomic_sub_return atomic_sub_return
+ATOMIC_OP_RETURN(sub, -)
+
+#define atomic_fetch_add atomic_fetch_add
+ATOMIC_FETCH_OP(add, +)
+#define atomic_fetch_sub atomic_fetch_sub
+ATOMIC_FETCH_OP(sub, -)
+#define atomic_fetch_and atomic_fetch_and
+ATOMIC_FETCH_OP(and, &)
+#define atomic_fetch_or atomic_fetch_or
+ATOMIC_FETCH_OP(or, |)
+#define atomic_fetch_xor atomic_fetch_xor
+ATOMIC_FETCH_OP(xor, ^)
+
+#define atomic_and atomic_and
+ATOMIC_OP(and, &)
+#define atomic_or atomic_or
+ATOMIC_OP(or, |)
+#define atomic_xor atomic_xor
+ATOMIC_OP(xor, ^)
+
+#undef ATOMIC_FETCH_OP
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
+#include <asm-generic/atomic.h>
+
+#endif /* __ASM_CSKY_ATOMIC_H */
diff --git a/arch/csky/include/asm/barrier.h b/arch/csky/include/asm/barrier.h
new file mode 100644
index 0000000..a430e7f
--- /dev/null
+++ b/arch/csky/include/asm/barrier.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_BARRIER_H
+#define __ASM_CSKY_BARRIER_H
+
+#ifndef __ASSEMBLY__
+
+#define nop()	asm volatile ("nop\n":::"memory")
+
+/*
+ * sync:        completion barrier, all sync.xx instructions
+ *              guarantee the last response recieved by bus transaction
+ *              made by ld/st instructions before sync.s
+ * sync.s:      inherit from sync, but also shareable to other cores
+ * sync.i:      inherit from sync, but also flush cpu pipeline
+ * sync.is:     the same with sync.i + sync.s
+ *
+ * bar.brwarw:  ordering barrier for all load/store instructions before it
+ * bar.brwarws: ordering barrier for all load/store instructions before it
+ *						and shareable to other cores
+ * bar.brar:    ordering barrier for all load       instructions before it
+ * bar.brars:   ordering barrier for all load       instructions before it
+ *						and shareable to other cores
+ * bar.bwaw:    ordering barrier for all store      instructions before it
+ * bar.bwaws:   ordering barrier for all store      instructions before it
+ *						and shareable to other cores
+ */
+
+#ifdef CONFIG_CPU_HAS_CACHEV2
+#define mb()		asm volatile ("sync.s\n":::"memory")
+
+#ifdef CONFIG_SMP
+#define __smp_mb()	asm volatile ("bar.brwarws\n":::"memory")
+#define __smp_rmb()	asm volatile ("bar.brars\n":::"memory")
+#define __smp_wmb()	asm volatile ("bar.bwaws\n":::"memory")
+#endif /* CONFIG_SMP */
+
+#define sync_is()	asm volatile ("sync.is\n":::"memory")
+
+#else /* !CONFIG_CPU_HAS_CACHEV2 */
+#define mb()		asm volatile ("sync\n":::"memory")
+#endif
+
+#include <asm-generic/barrier.h>
+
+#endif /* __ASSEMBLY__ */
+#endif /* __ASM_CSKY_BARRIER_H */
diff --git a/arch/csky/include/asm/bitops.h b/arch/csky/include/asm/bitops.h
new file mode 100644
index 0000000..43b9838
--- /dev/null
+++ b/arch/csky/include/asm/bitops.h
@@ -0,0 +1,82 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_BITOPS_H
+#define __ASM_CSKY_BITOPS_H
+
+#include <linux/compiler.h>
+#include <asm/barrier.h>
+
+/*
+ * asm-generic/bitops/ffs.h
+ */
+static inline int ffs(int x)
+{
+	if (!x)
+		return 0;
+
+	asm volatile (
+		"brev %0\n"
+		"ff1  %0\n"
+		"addi %0, 1\n"
+		: "=&r"(x)
+		: "0"(x));
+	return x;
+}
+
+/*
+ * asm-generic/bitops/__ffs.h
+ */
+static __always_inline unsigned long __ffs(unsigned long x)
+{
+	asm volatile (
+		"brev %0\n"
+		"ff1  %0\n"
+		: "=&r"(x)
+		: "0"(x));
+	return x;
+}
+
+/*
+ * asm-generic/bitops/fls.h
+ */
+static __always_inline int fls(unsigned int x)
+{
+	asm volatile(
+		"ff1 %0\n"
+		: "=&r"(x)
+		: "0"(x));
+
+	return (32 - x);
+}
+
+/*
+ * asm-generic/bitops/__fls.h
+ */
+static __always_inline unsigned long __fls(unsigned long x)
+{
+	return fls(x) - 1;
+}
+
+#include <asm-generic/bitops/ffz.h>
+#include <asm-generic/bitops/fls64.h>
+#include <asm-generic/bitops/find.h>
+
+#ifndef _LINUX_BITOPS_H
+#error only <linux/bitops.h> can be included directly
+#endif
+
+#include <asm-generic/bitops/sched.h>
+#include <asm-generic/bitops/hweight.h>
+#include <asm-generic/bitops/lock.h>
+#include <asm-generic/bitops/atomic.h>
+
+/*
+ * bug fix, why only could use atomic!!!!
+ */
+#include <asm-generic/bitops/non-atomic.h>
+#define __clear_bit(nr, vaddr) clear_bit(nr, vaddr)
+
+#include <asm-generic/bitops/le.h>
+#include <asm-generic/bitops/ext2-atomic.h>
+#endif /* __ASM_CSKY_BITOPS_H */
diff --git a/arch/csky/include/asm/bug.h b/arch/csky/include/asm/bug.h
new file mode 100644
index 0000000..bd7b323
--- /dev/null
+++ b/arch/csky/include/asm/bug.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_BUG_H
+#define __ASM_CSKY_BUG_H
+
+#include <linux/compiler.h>
+#include <linux/const.h>
+#include <linux/types.h>
+
+#define BUG()				\
+do {					\
+	asm volatile ("bkpt\n");	\
+	unreachable();			\
+} while (0)
+
+#define HAVE_ARCH_BUG
+
+#include <asm-generic/bug.h>
+
+struct pt_regs;
+
+void die_if_kernel(char *str, struct pt_regs *regs, int nr);
+void show_regs(struct pt_regs *regs);
+
+#endif /* __ASM_CSKY_BUG_H */
diff --git a/arch/csky/include/asm/cache.h b/arch/csky/include/asm/cache.h
new file mode 100644
index 0000000..1d5fc2f
--- /dev/null
+++ b/arch/csky/include/asm/cache.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_CACHE_H
+#define __ASM_CSKY_CACHE_H
+
+/* bytes per L1 cache line */
+#define L1_CACHE_SHIFT	CONFIG_L1_CACHE_SHIFT
+
+#define L1_CACHE_BYTES	(1 << L1_CACHE_SHIFT)
+
+#define ARCH_DMA_MINALIGN	L1_CACHE_BYTES
+
+#ifndef __ASSEMBLY__
+
+void dcache_wb_line(unsigned long start);
+
+void icache_inv_range(unsigned long start, unsigned long end);
+void icache_inv_all(void);
+
+void dcache_wb_range(unsigned long start, unsigned long end);
+void dcache_wbinv_all(void);
+
+void cache_wbinv_range(unsigned long start, unsigned long end);
+void cache_wbinv_all(void);
+
+void dma_wbinv_range(unsigned long start, unsigned long end);
+void dma_inv_range(unsigned long start, unsigned long end);
+void dma_wb_range(unsigned long start, unsigned long end);
+
+#endif
+#endif  /* __ASM_CSKY_CACHE_H */
diff --git a/arch/csky/include/asm/cacheflush.h b/arch/csky/include/asm/cacheflush.h
new file mode 100644
index 0000000..a96da67
--- /dev/null
+++ b/arch/csky/include/asm/cacheflush.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_CACHEFLUSH_H
+#define __ASM_CSKY_CACHEFLUSH_H
+
+#include <abi/cacheflush.h>
+
+#endif /* __ASM_CSKY_CACHEFLUSH_H */
diff --git a/arch/csky/include/asm/checksum.h b/arch/csky/include/asm/checksum.h
new file mode 100644
index 0000000..7685824
--- /dev/null
+++ b/arch/csky/include/asm/checksum.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_CHECKSUM_H
+#define __ASM_CSKY_CHECKSUM_H
+
+#include <linux/in6.h>
+#include <asm/byteorder.h>
+
+static inline __sum16 csum_fold(__wsum csum)
+{
+	u32 tmp;
+
+	asm volatile(
+	"mov	%1, %0\n"
+	"rori	%0, 16\n"
+	"addu	%0, %1\n"
+	"lsri	%0, 16\n"
+	: "=r"(csum), "=r"(tmp)
+	: "0"(csum));
+
+	return (__force __sum16) ~csum;
+}
+#define csum_fold csum_fold
+
+static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
+		unsigned short len, unsigned short proto, __wsum sum)
+{
+	asm volatile(
+	"clrc\n"
+	"addc    %0, %1\n"
+	"addc    %0, %2\n"
+	"addc    %0, %3\n"
+	"inct    %0\n"
+	: "=r"(sum)
+	: "r"((__force u32)saddr), "r"((__force u32)daddr),
+#ifdef __BIG_ENDIAN
+	"r"(proto + len),
+#else
+	"r"((proto + len) << 8),
+#endif
+	"0" ((__force unsigned long)sum)
+	: "cc");
+	return sum;
+}
+#define csum_tcpudp_nofold csum_tcpudp_nofold
+
+#include <asm-generic/checksum.h>
+
+#endif /* __ASM_CSKY_CHECKSUM_H */
diff --git a/arch/csky/include/asm/cmpxchg.h b/arch/csky/include/asm/cmpxchg.h
new file mode 100644
index 0000000..8922453
--- /dev/null
+++ b/arch/csky/include/asm/cmpxchg.h
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_CMPXCHG_H
+#define __ASM_CSKY_CMPXCHG_H
+
+#ifdef CONFIG_CPU_HAS_LDSTEX
+#include <asm/barrier.h>
+
+extern void __bad_xchg(void);
+
+#define __xchg(new, ptr, size)					\
+({								\
+	__typeof__(ptr) __ptr = (ptr);				\
+	__typeof__(new) __new = (new);				\
+	__typeof__(*(ptr)) __ret;				\
+	unsigned long tmp;					\
+	switch (size) {						\
+	case 4:							\
+		smp_mb();					\
+		asm volatile (					\
+		"1:	ldex.w		%0, (%3) \n"		\
+		"	mov		%1, %2   \n"		\
+		"	stex.w		%1, (%3) \n"		\
+		"	bez		%1, 1b   \n"		\
+			: "=&r" (__ret), "=&r" (tmp)		\
+			: "r" (__new), "r"(__ptr)		\
+			:);					\
+		smp_mb();					\
+		break;						\
+	default:						\
+		__bad_xchg();					\
+	}							\
+	__ret;							\
+})
+
+#define xchg(ptr, x)	(__xchg((x), (ptr), sizeof(*(ptr))))
+
+#define __cmpxchg(ptr, old, new, size)				\
+({								\
+	__typeof__(ptr) __ptr = (ptr);				\
+	__typeof__(new) __new = (new);				\
+	__typeof__(new) __tmp;					\
+	__typeof__(old) __old = (old);				\
+	__typeof__(*(ptr)) __ret;				\
+	switch (size) {						\
+	case 4:							\
+		smp_mb();					\
+		asm volatile (					\
+		"1:	ldex.w		%0, (%3) \n"		\
+		"	cmpne		%0, %4   \n"		\
+		"	bt		2f       \n"		\
+		"	mov		%1, %2   \n"		\
+		"	stex.w		%1, (%3) \n"		\
+		"	bez		%1, 1b   \n"		\
+		"2:				 \n"		\
+			: "=&r" (__ret), "=&r" (__tmp)		\
+			: "r" (__new), "r"(__ptr), "r"(__old)	\
+			:);					\
+		smp_mb();					\
+		break;						\
+	default:						\
+		__bad_xchg();					\
+	}							\
+	__ret;							\
+})
+
+#define cmpxchg(ptr, o, n) \
+	(__cmpxchg((ptr), (o), (n), sizeof(*(ptr))))
+#else
+#include <asm-generic/cmpxchg.h>
+#endif
+
+#endif /* __ASM_CSKY_CMPXCHG_H */
diff --git a/arch/csky/include/asm/elf.h b/arch/csky/include/asm/elf.h
new file mode 100644
index 0000000..e1ec558
--- /dev/null
+++ b/arch/csky/include/asm/elf.h
@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_ELF_H
+#define __ASM_CSKY_ELF_H
+
+#include <asm/ptrace.h>
+#include <abi/regdef.h>
+
+#define ELF_ARCH EM_CSKY
+#define EM_CSKY_OLD 39
+
+/* CSKY Relocations */
+#define R_CSKY_NONE               0
+#define R_CSKY_32                 1
+#define R_CSKY_PCIMM8BY4          2
+#define R_CSKY_PCIMM11BY2         3
+#define R_CSKY_PCIMM4BY2          4
+#define R_CSKY_PC32               5
+#define R_CSKY_PCRELJSR_IMM11BY2  6
+#define R_CSKY_GNU_VTINHERIT      7
+#define R_CSKY_GNU_VTENTRY        8
+#define R_CSKY_RELATIVE           9
+#define R_CSKY_COPY               10
+#define R_CSKY_GLOB_DAT           11
+#define R_CSKY_JUMP_SLOT          12
+#define R_CSKY_ADDR_HI16          24
+#define R_CSKY_ADDR_LO16          25
+#define R_CSKY_PCRELJSR_IMM26BY2  40
+
+typedef unsigned long elf_greg_t;
+
+typedef struct user_fp elf_fpregset_t;
+
+/*
+ * In gdb/bfd elf32-csky.c, csky_elf_grok_prstatus() use fixed size of
+ * elf_prstatus. It's 148 for abiv1 and 220 for abiv2, the size is enough
+ * for coredump and no need full sizeof(struct pt_regs).
+ */
+#define ELF_NGREG ((sizeof(struct pt_regs) / sizeof(elf_greg_t)) - 2)
+
+typedef elf_greg_t elf_gregset_t[ELF_NGREG];
+
+/*
+ * This is used to ensure we don't load something for the wrong architecture.
+ */
+#define elf_check_arch(x) (((x)->e_machine == ELF_ARCH) || \
+			   ((x)->e_machine == EM_CSKY_OLD))
+
+/*
+ * These are used to set parameters in the core dumps.
+ */
+#define USE_ELF_CORE_DUMP
+#define ELF_EXEC_PAGESIZE		4096
+#define ELF_CLASS			ELFCLASS32
+#define ELF_PLAT_INIT(_r, load_addr)	{ _r->a0 = 0; }
+
+#ifdef __cskyBE__
+#define ELF_DATA	ELFDATA2MSB
+#else
+#define ELF_DATA	ELFDATA2LSB
+#endif
+
+/*
+ * This is the location that an ET_DYN program is loaded if exec'ed. Typical
+ * use of this is to invoke "./ld.so someprog" to test out a new version of
+ * the loader.  We need to make sure that it is out of the way of the program
+ * that it will "exec", and that there is sufficient room for the brk.
+ */
+#define ELF_ET_DYN_BASE	0x0UL
+#include <abi/elf.h>
+
+/* Similar, but for a thread other than current. */
+struct task_struct;
+extern int dump_task_regs(struct task_struct *tsk, elf_gregset_t *elf_regs);
+#define ELF_CORE_COPY_TASK_REGS(tsk, elf_regs) dump_task_regs(tsk, elf_regs)
+
+#define ELF_HWCAP	(0)
+
+/*
+ * This yields a string that ld.so will use to load implementation specific
+ * libraries for optimization. This is more specific in intent than poking
+ * at uname or /proc/cpuinfo.
+ */
+#define ELF_PLATFORM		(NULL)
+#define SET_PERSONALITY(ex)	set_personality(PER_LINUX)
+
+#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
+struct linux_binprm;
+extern int arch_setup_additional_pages(struct linux_binprm *bprm,
+				       int uses_interp);
+#endif /* __ASM_CSKY_ELF_H */
diff --git a/arch/csky/include/asm/fixmap.h b/arch/csky/include/asm/fixmap.h
new file mode 100644
index 0000000..380ff0a
--- /dev/null
+++ b/arch/csky/include/asm/fixmap.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_FIXMAP_H
+#define __ASM_CSKY_FIXMAP_H
+
+#include <asm/page.h>
+#ifdef CONFIG_HIGHMEM
+#include <linux/threads.h>
+#include <asm/kmap_types.h>
+#endif
+
+enum fixed_addresses {
+#ifdef CONFIG_HIGHMEM
+	FIX_KMAP_BEGIN,
+	FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * NR_CPUS) - 1,
+#endif
+	__end_of_fixed_addresses
+};
+
+#define FIXADDR_TOP	0xffffc000
+#define FIXADDR_SIZE	(__end_of_fixed_addresses << PAGE_SHIFT)
+#define FIXADDR_START	(FIXADDR_TOP - FIXADDR_SIZE)
+
+#include <asm-generic/fixmap.h>
+
+#endif /* __ASM_CSKY_FIXMAP_H */
diff --git a/arch/csky/include/asm/ftrace.h b/arch/csky/include/asm/ftrace.h
new file mode 100644
index 0000000..ba35d93
--- /dev/null
+++ b/arch/csky/include/asm/ftrace.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_FTRACE_H
+#define __ASM_CSKY_FTRACE_H
+
+#define MCOUNT_INSN_SIZE	14
+
+#define HAVE_FUNCTION_GRAPH_FP_TEST
+
+#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
+
+#define MCOUNT_ADDR	((unsigned long)_mcount)
+
+#ifndef __ASSEMBLY__
+
+extern void _mcount(unsigned long);
+
+extern void ftrace_graph_call(void);
+
+static inline unsigned long ftrace_call_adjust(unsigned long addr)
+{
+	return addr;
+}
+
+struct dyn_arch_ftrace {
+};
+#endif /* !__ASSEMBLY__ */
+#endif /* __ASM_CSKY_FTRACE_H */
diff --git a/arch/csky/include/asm/highmem.h b/arch/csky/include/asm/highmem.h
new file mode 100644
index 0000000..a345a2f
--- /dev/null
+++ b/arch/csky/include/asm/highmem.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_HIGHMEM_H
+#define __ASM_CSKY_HIGHMEM_H
+
+#ifdef __KERNEL__
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/uaccess.h>
+#include <asm/kmap_types.h>
+#include <asm/cache.h>
+
+/* undef for production */
+#define HIGHMEM_DEBUG 1
+
+/* declarations for highmem.c */
+extern unsigned long highstart_pfn, highend_pfn;
+
+extern pte_t *pkmap_page_table;
+
+/*
+ * Right now we initialize only a single pte table. It can be extended
+ * easily, subsequent pte tables have to be allocated in one physical
+ * chunk of RAM.
+ */
+#define LAST_PKMAP 1024
+#define LAST_PKMAP_MASK (LAST_PKMAP-1)
+#define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
+#define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
+
+extern void *kmap_high(struct page *page);
+extern void kunmap_high(struct page *page);
+
+extern void *kmap(struct page *page);
+extern void kunmap(struct page *page);
+extern void *kmap_atomic(struct page *page);
+extern void __kunmap_atomic(void *kvaddr);
+extern void *kmap_atomic_pfn(unsigned long pfn);
+extern struct page *kmap_atomic_to_page(void *ptr);
+
+#define flush_cache_kmaps() do {} while (0)
+
+extern void kmap_init(void);
+
+#define kmap_prot PAGE_KERNEL
+
+#endif /* __KERNEL__ */
+
+#endif /* __ASM_CSKY_HIGHMEM_H */
diff --git a/arch/csky/include/asm/io.h b/arch/csky/include/asm/io.h
new file mode 100644
index 0000000..80d071e
--- /dev/null
+++ b/arch/csky/include/asm/io.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_IO_H
+#define __ASM_CSKY_IO_H
+
+#include <asm/pgtable.h>
+#include <linux/types.h>
+#include <linux/version.h>
+
+/*
+ * I/O memory access primitives. Reads are ordered relative to any
+ * following Normal memory access. Writes are ordered relative to any prior
+ * Normal memory access.
+ *
+ * For CACHEV1 (807, 810), store instruction could fast retire, so we need
+ * another mb() to prevent st fast retire.
+ *
+ * For CACHEV2 (860), store instruction with PAGE_ATTR_NO_BUFFERABLE won't
+ * fast retire.
+ */
+#define readb(c)		({ u8  __v = readb_relaxed(c); rmb(); __v; })
+#define readw(c)		({ u16 __v = readw_relaxed(c); rmb(); __v; })
+#define readl(c)		({ u32 __v = readl_relaxed(c); rmb(); __v; })
+
+#ifdef CONFIG_CPU_HAS_CACHEV2
+#define writeb(v,c)		({ wmb(); writeb_relaxed((v),(c)); })
+#define writew(v,c)		({ wmb(); writew_relaxed((v),(c)); })
+#define writel(v,c)		({ wmb(); writel_relaxed((v),(c)); })
+#else
+#define writeb(v,c)		({ wmb(); writeb_relaxed((v),(c)); mb(); })
+#define writew(v,c)		({ wmb(); writew_relaxed((v),(c)); mb(); })
+#define writel(v,c)		({ wmb(); writel_relaxed((v),(c)); mb(); })
+#endif
+
+/*
+ * I/O memory mapping functions.
+ */
+extern void __iomem *ioremap_cache(phys_addr_t addr, size_t size);
+extern void __iomem *__ioremap(phys_addr_t addr, size_t size, pgprot_t prot);
+extern void iounmap(void *addr);
+
+#define ioremap(addr, size)		__ioremap((addr), (size), pgprot_noncached(PAGE_KERNEL))
+#define ioremap_wc(addr, size)		__ioremap((addr), (size), pgprot_writecombine(PAGE_KERNEL))
+#define ioremap_nocache(addr, size)	ioremap((addr), (size))
+#define ioremap_cache			ioremap_cache
+
+#include <asm-generic/io.h>
+
+#endif /* __ASM_CSKY_IO_H */
diff --git a/arch/csky/include/asm/irqflags.h b/arch/csky/include/asm/irqflags.h
new file mode 100644
index 0000000..9e3a569
--- /dev/null
+++ b/arch/csky/include/asm/irqflags.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_IRQFLAGS_H
+#define __ASM_CSKY_IRQFLAGS_H
+#include <abi/reg_ops.h>
+
+static inline unsigned long arch_local_irq_save(void)
+{
+	unsigned long flags;
+
+	flags = mfcr("psr");
+	asm volatile("psrclr ie\n":::"memory");
+	return flags;
+}
+#define arch_local_irq_save arch_local_irq_save
+
+static inline void arch_local_irq_enable(void)
+{
+	asm volatile("psrset ee, ie\n":::"memory");
+}
+#define arch_local_irq_enable arch_local_irq_enable
+
+static inline void arch_local_irq_disable(void)
+{
+	asm volatile("psrclr ie\n":::"memory");
+}
+#define arch_local_irq_disable arch_local_irq_disable
+
+static inline unsigned long arch_local_save_flags(void)
+{
+	return mfcr("psr");
+}
+#define arch_local_save_flags arch_local_save_flags
+
+static inline void arch_local_irq_restore(unsigned long flags)
+{
+	mtcr("psr", flags);
+}
+#define arch_local_irq_restore arch_local_irq_restore
+
+static inline int arch_irqs_disabled_flags(unsigned long flags)
+{
+	return !(flags & (1<<6));
+}
+#define arch_irqs_disabled_flags arch_irqs_disabled_flags
+
+#include <asm-generic/irqflags.h>
+
+#endif /* __ASM_CSKY_IRQFLAGS_H */
diff --git a/arch/csky/include/asm/mmu.h b/arch/csky/include/asm/mmu.h
new file mode 100644
index 0000000..b382a14
--- /dev/null
+++ b/arch/csky/include/asm/mmu.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_MMU_H
+#define __ASM_CSKY_MMU_H
+
+typedef struct {
+	atomic64_t	asid;
+	void *vdso;
+} mm_context_t;
+
+#endif /* __ASM_CSKY_MMU_H */
diff --git a/arch/csky/include/asm/mmu_context.h b/arch/csky/include/asm/mmu_context.h
new file mode 100644
index 0000000..0285b0a
--- /dev/null
+++ b/arch/csky/include/asm/mmu_context.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_MMU_CONTEXT_H
+#define __ASM_CSKY_MMU_CONTEXT_H
+
+#include <asm-generic/mm_hooks.h>
+#include <asm/setup.h>
+#include <asm/page.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <abi/ckmmu.h>
+
+#define TLBMISS_HANDLER_SETUP_PGD(pgd) \
+	setup_pgd(__pa(pgd), false)
+
+#define TLBMISS_HANDLER_SETUP_PGD_KERNEL(pgd) \
+	setup_pgd(__pa(pgd), true)
+
+#define ASID_MASK		((1 << CONFIG_CPU_ASID_BITS) - 1)
+#define cpu_asid(mm)		(atomic64_read(&mm->context.asid) & ASID_MASK)
+
+#define init_new_context(tsk,mm)	({ atomic64_set(&(mm)->context.asid, 0); 0; })
+#define activate_mm(prev,next)		switch_mm(prev, next, current)
+
+#define destroy_context(mm)		do {} while (0)
+#define enter_lazy_tlb(mm, tsk)		do {} while (0)
+#define deactivate_mm(tsk, mm)		do {} while (0)
+
+void check_and_switch_context(struct mm_struct *mm, unsigned int cpu);
+
+static inline void
+switch_mm(struct mm_struct *prev, struct mm_struct *next,
+	  struct task_struct *tsk)
+{
+	unsigned int cpu = smp_processor_id();
+
+	if (prev != next)
+		check_and_switch_context(next, cpu);
+
+	TLBMISS_HANDLER_SETUP_PGD(next->pgd);
+	write_mmu_entryhi(next->context.asid.counter);
+}
+#endif /* __ASM_CSKY_MMU_CONTEXT_H */
diff --git a/arch/csky/include/asm/page.h b/arch/csky/include/asm/page.h
new file mode 100644
index 0000000..9738eac
--- /dev/null
+++ b/arch/csky/include/asm/page.h
@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_PAGE_H
+#define __ASM_CSKY_PAGE_H
+
+#include <asm/setup.h>
+#include <asm/cache.h>
+#include <linux/const.h>
+
+/*
+ * PAGE_SHIFT determines the page size: 4KB
+ */
+#define PAGE_SHIFT	12
+#define PAGE_SIZE	(_AC(1, UL) << PAGE_SHIFT)
+#define PAGE_MASK	(~(PAGE_SIZE - 1))
+#define THREAD_SIZE	(PAGE_SIZE * 2)
+#define THREAD_MASK	(~(THREAD_SIZE - 1))
+#define THREAD_SHIFT	(PAGE_SHIFT + 1)
+
+
+/*
+ * For C-SKY "User-space:Kernel-space" is "2GB:2GB" fixed by hardware and there
+ * are two segment registers (MSA0 + MSA1) to mapping 512MB + 512MB physical
+ * address region. We use them mapping kernel 1GB direct-map address area and
+ * for more than 1GB of memory we use highmem.
+ */
+#define PAGE_OFFSET	0x80000000
+#define SSEG_SIZE	0x20000000
+#define LOWMEM_LIMIT	(SSEG_SIZE * 2)
+
+#define PHYS_OFFSET_OFFSET (CONFIG_RAM_BASE & (SSEG_SIZE - 1))
+
+#ifndef __ASSEMBLY__
+
+#include <linux/pfn.h>
+
+#define virt_to_pfn(kaddr)      (__pa(kaddr) >> PAGE_SHIFT)
+#define pfn_to_virt(pfn)        __va((pfn) << PAGE_SHIFT)
+
+#define virt_addr_valid(kaddr)  ((void *)(kaddr) >= (void *)PAGE_OFFSET && \
+			(void *)(kaddr) < high_memory)
+#define pfn_valid(pfn)		((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr)
+
+extern void *memset(void *dest, int c, size_t l);
+extern void *memcpy(void *to, const void *from, size_t l);
+
+#define clear_page(page)	memset((page), 0, PAGE_SIZE)
+#define copy_page(to, from)	memcpy((to), (from), PAGE_SIZE)
+
+#define page_to_phys(page)	(page_to_pfn(page) << PAGE_SHIFT)
+#define phys_to_page(paddr)	(pfn_to_page(PFN_DOWN(paddr)))
+
+struct page;
+
+#include <abi/page.h>
+
+struct vm_area_struct;
+
+typedef struct { unsigned long pte_low; } pte_t;
+#define pte_val(x)	((x).pte_low)
+
+typedef struct { unsigned long pgd; } pgd_t;
+typedef struct { unsigned long pgprot; } pgprot_t;
+typedef struct page *pgtable_t;
+
+#define pgd_val(x)	((x).pgd)
+#define pgprot_val(x)	((x).pgprot)
+
+#define ptep_buddy(x)	((pte_t *)((unsigned long)(x) ^ sizeof(pte_t)))
+
+#define __pte(x)	((pte_t) { (x) })
+#define __pgd(x)	((pgd_t) { (x) })
+#define __pgprot(x)	((pgprot_t) { (x) })
+
+extern unsigned long va_pa_offset;
+
+#define ARCH_PFN_OFFSET	PFN_DOWN(va_pa_offset + PHYS_OFFSET_OFFSET)
+
+#define __pa(x)		 ((unsigned long)(x) - PAGE_OFFSET + va_pa_offset)
+#define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET - va_pa_offset))
+
+#define __pa_symbol(x)	__pa(RELOC_HIDE((unsigned long)(x), 0))
+
+#define MAP_NR(x)	PFN_DOWN((unsigned long)(x) - PAGE_OFFSET - \
+				 PHYS_OFFSET_OFFSET)
+#define virt_to_page(x)	(mem_map + MAP_NR(x))
+
+#define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | VM_EXEC | \
+				VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+
+#define pfn_to_kaddr(x)	__va(PFN_PHYS(x))
+
+#include <asm-generic/memory_model.h>
+#include <asm-generic/getorder.h>
+
+#endif /* !__ASSEMBLY__ */
+#endif /* __ASM_CSKY_PAGE_H */
diff --git a/arch/csky/include/asm/perf_event.h b/arch/csky/include/asm/perf_event.h
new file mode 100644
index 0000000..572093e
--- /dev/null
+++ b/arch/csky/include/asm/perf_event.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_PERF_EVENT_H
+#define __ASM_CSKY_PERF_EVENT_H
+
+#include <abi/regdef.h>
+
+#define perf_arch_fetch_caller_regs(regs, __ip) { \
+	(regs)->pc = (__ip); \
+	regs_fp(regs) = (unsigned long) __builtin_frame_address(0); \
+	asm volatile("mov %0, sp\n":"=r"((regs)->usp)); \
+}
+
+#endif /* __ASM_PERF_EVENT_ELF_H */
diff --git a/arch/csky/include/asm/pgalloc.h b/arch/csky/include/asm/pgalloc.h
new file mode 100644
index 0000000..c7c1ed2
--- /dev/null
+++ b/arch/csky/include/asm/pgalloc.h
@@ -0,0 +1,82 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_PGALLOC_H
+#define __ASM_CSKY_PGALLOC_H
+
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+
+#define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
+#include <asm-generic/pgalloc.h>	/* for pte_{alloc,free}_one */
+
+static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
+					pte_t *pte)
+{
+	set_pmd(pmd, __pmd(__pa(pte)));
+}
+
+static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
+					pgtable_t pte)
+{
+	set_pmd(pmd, __pmd(__pa(page_address(pte))));
+}
+
+#define pmd_pgtable(pmd) pmd_page(pmd)
+
+extern void pgd_init(unsigned long *p);
+
+static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
+{
+	pte_t *pte;
+	unsigned long i;
+
+	pte = (pte_t *) __get_free_page(GFP_KERNEL);
+	if (!pte)
+		return NULL;
+
+	for (i = 0; i < PAGE_SIZE/sizeof(pte_t); i++)
+		(pte + i)->pte_low = _PAGE_GLOBAL;
+
+	return pte;
+}
+
+static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
+{
+	free_pages((unsigned long)pgd, PGD_ORDER);
+}
+
+static inline pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+	pgd_t *ret;
+	pgd_t *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));
+		/* prevent out of order excute */
+		smp_mb();
+#ifdef CONFIG_CPU_NEED_TLBSYNC
+		dcache_wb_range((unsigned int)ret,
+				(unsigned int)(ret + PTRS_PER_PGD));
+#endif
+	}
+
+	return ret;
+}
+
+#define __pte_free_tlb(tlb, pte, address)		\
+do {							\
+	pgtable_pte_page_dtor(pte);			\
+	tlb_remove_page(tlb, pte);			\
+} while (0)
+
+extern void pagetable_init(void);
+extern void pre_mmu_init(void);
+extern void pre_trap_init(void);
+
+#endif /* __ASM_CSKY_PGALLOC_H */
diff --git a/arch/csky/include/asm/pgtable.h b/arch/csky/include/asm/pgtable.h
new file mode 100644
index 0000000..7c21985
--- /dev/null
+++ b/arch/csky/include/asm/pgtable.h
@@ -0,0 +1,314 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_PGTABLE_H
+#define __ASM_CSKY_PGTABLE_H
+
+#include <asm/fixmap.h>
+#include <asm/addrspace.h>
+#include <abi/pgtable-bits.h>
+#include <asm-generic/pgtable-nopmd.h>
+
+#define PGDIR_SHIFT		22
+#define PGDIR_SIZE		(1UL << PGDIR_SHIFT)
+#define PGDIR_MASK		(~(PGDIR_SIZE-1))
+
+#define USER_PTRS_PER_PGD	(0x80000000UL/PGDIR_SIZE)
+#define FIRST_USER_ADDRESS	0UL
+
+#define PKMAP_BASE		(0xff800000)
+
+#define VMALLOC_START		(0xc0008000)
+#define VMALLOC_END		(PKMAP_BASE - 2*PAGE_SIZE)
+
+/*
+ * C-SKY is two-level paging structure:
+ */
+#define PGD_ORDER	0
+#define PTE_ORDER	0
+
+#define PTRS_PER_PGD	((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t))
+#define PTRS_PER_PMD	1
+#define PTRS_PER_PTE	((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
+
+#define pte_ERROR(e) \
+	pr_err("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, (e).pte_low)
+#define pgd_ERROR(e) \
+	pr_err("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
+
+/* Find an entry in the third-level page table.. */
+#define __pte_offset_t(address) \
+	(((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
+#define pte_offset_kernel(dir, address) \
+	(pmd_page_vaddr(*(dir)) + __pte_offset_t(address))
+#define pte_offset_map(dir, address) \
+	((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset_t(address))
+#define pmd_page(pmd)	(pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
+#define pte_clear(mm, addr, ptep)	set_pte((ptep), \
+	(((unsigned int) addr & PAGE_OFFSET) ? __pte(_PAGE_GLOBAL) : __pte(0)))
+#define pte_none(pte)		(!(pte_val(pte) & ~_PAGE_GLOBAL))
+#define pte_present(pte)	(pte_val(pte) & _PAGE_PRESENT)
+#define pte_pfn(x)	((unsigned long)((x).pte_low >> PAGE_SHIFT))
+#define pfn_pte(pfn, prot) __pte(((unsigned long long)(pfn) << PAGE_SHIFT) \
+				| pgprot_val(prot))
+
+#define __READABLE	(_PAGE_READ | _PAGE_VALID | _PAGE_ACCESSED)
+#define __WRITEABLE	(_PAGE_WRITE | _PAGE_DIRTY | _PAGE_MODIFIED)
+
+#define _PAGE_CHG_MASK	(PAGE_MASK | _PAGE_ACCESSED | _PAGE_MODIFIED | \
+			 _CACHE_MASK)
+
+#define pte_unmap(pte)	((void)(pte))
+
+#define __swp_type(x)			(((x).val >> 4) & 0xff)
+#define __swp_offset(x)			((x).val >> 12)
+#define __swp_entry(type, offset)	((swp_entry_t) {((type) << 4) | \
+					((offset) << 12) })
+#define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
+#define __swp_entry_to_pte(x)		((pte_t) { (x).val })
+
+#define pte_page(x)			pfn_to_page(pte_pfn(x))
+#define __mk_pte(page_nr, pgprot)	__pte(((page_nr) << PAGE_SHIFT) | \
+					pgprot_val(pgprot))
+
+/*
+ * CSKY can't do page protection for execute, and considers that the same like
+ * read. Also, write permissions imply read permissions. This is the closest
+ * we can get by reasonable means..
+ */
+#define PAGE_NONE	__pgprot(_PAGE_PRESENT | _CACHE_CACHED)
+#define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
+				_CACHE_CACHED)
+#define PAGE_COPY	__pgprot(_PAGE_PRESENT | _PAGE_READ | _CACHE_CACHED)
+#define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_READ | _CACHE_CACHED)
+#define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
+				_PAGE_GLOBAL | _CACHE_CACHED)
+#define PAGE_USERIO	__pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
+				_CACHE_CACHED)
+
+#define __P000	PAGE_NONE
+#define __P001	PAGE_READONLY
+#define __P010	PAGE_COPY
+#define __P011	PAGE_COPY
+#define __P100	PAGE_READONLY
+#define __P101	PAGE_READONLY
+#define __P110	PAGE_COPY
+#define __P111	PAGE_COPY
+
+#define __S000	PAGE_NONE
+#define __S001	PAGE_READONLY
+#define __S010	PAGE_SHARED
+#define __S011	PAGE_SHARED
+#define __S100	PAGE_READONLY
+#define __S101	PAGE_READONLY
+#define __S110	PAGE_SHARED
+#define __S111	PAGE_SHARED
+
+extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
+#define ZERO_PAGE(vaddr)	(virt_to_page(empty_zero_page))
+
+extern void load_pgd(unsigned long pg_dir);
+extern pte_t invalid_pte_table[PTRS_PER_PTE];
+
+static inline int pte_special(pte_t pte) { return 0; }
+static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
+
+static inline void set_pte(pte_t *p, pte_t pte)
+{
+	*p = pte;
+#if defined(CONFIG_CPU_NEED_TLBSYNC)
+	dcache_wb_line((u32)p);
+#endif
+	/* prevent out of order excution */
+	smp_mb();
+}
+#define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval)
+
+static inline pte_t *pmd_page_vaddr(pmd_t pmd)
+{
+	unsigned long ptr;
+
+	ptr = pmd_val(pmd);
+
+	return __va(ptr);
+}
+
+#define pmd_phys(pmd) pmd_val(pmd)
+
+static inline void set_pmd(pmd_t *p, pmd_t pmd)
+{
+	*p = pmd;
+#if defined(CONFIG_CPU_NEED_TLBSYNC)
+	dcache_wb_line((u32)p);
+#endif
+	/* prevent specul excute */
+	smp_mb();
+}
+
+
+static inline int pmd_none(pmd_t pmd)
+{
+	return pmd_val(pmd) == __pa(invalid_pte_table);
+}
+
+#define pmd_bad(pmd)	(pmd_val(pmd) & ~PAGE_MASK)
+
+static inline int pmd_present(pmd_t pmd)
+{
+	return (pmd_val(pmd) != __pa(invalid_pte_table));
+}
+
+static inline void pmd_clear(pmd_t *p)
+{
+	pmd_val(*p) = (__pa(invalid_pte_table));
+#if defined(CONFIG_CPU_NEED_TLBSYNC)
+	dcache_wb_line((u32)p);
+#endif
+}
+
+/*
+ * The following only work if pte_present() is true.
+ * Undefined behaviour if not..
+ */
+static inline int pte_read(pte_t pte)
+{
+	return pte.pte_low & _PAGE_READ;
+}
+
+static inline int pte_write(pte_t pte)
+{
+	return (pte).pte_low & _PAGE_WRITE;
+}
+
+static inline int pte_dirty(pte_t pte)
+{
+	return (pte).pte_low & _PAGE_MODIFIED;
+}
+
+static inline int pte_young(pte_t pte)
+{
+	return (pte).pte_low & _PAGE_ACCESSED;
+}
+
+static inline pte_t pte_wrprotect(pte_t pte)
+{
+	pte_val(pte) &= ~(_PAGE_WRITE | _PAGE_DIRTY);
+	return pte;
+}
+
+static inline pte_t pte_mkclean(pte_t pte)
+{
+	pte_val(pte) &= ~(_PAGE_MODIFIED|_PAGE_DIRTY);
+	return pte;
+}
+
+static inline pte_t pte_mkold(pte_t pte)
+{
+	pte_val(pte) &= ~(_PAGE_ACCESSED|_PAGE_VALID);
+	return pte;
+}
+
+static inline pte_t pte_mkwrite(pte_t pte)
+{
+	pte_val(pte) |= _PAGE_WRITE;
+	if (pte_val(pte) & _PAGE_MODIFIED)
+		pte_val(pte) |= _PAGE_DIRTY;
+	return pte;
+}
+
+static inline pte_t pte_mkdirty(pte_t pte)
+{
+	pte_val(pte) |= _PAGE_MODIFIED;
+	if (pte_val(pte) & _PAGE_WRITE)
+		pte_val(pte) |= _PAGE_DIRTY;
+	return pte;
+}
+
+static inline pte_t pte_mkyoung(pte_t pte)
+{
+	pte_val(pte) |= _PAGE_ACCESSED;
+	if (pte_val(pte) & _PAGE_READ)
+		pte_val(pte) |= _PAGE_VALID;
+	return pte;
+}
+
+#define __pgd_offset(address)	pgd_index(address)
+#define __pud_offset(address)	(((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
+#define __pmd_offset(address)	(((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
+
+/* to find an entry in a kernel page-table-directory */
+#define pgd_offset_k(address)	pgd_offset(&init_mm, address)
+
+#define pgd_index(address)	((address) >> PGDIR_SHIFT)
+
+#define __HAVE_PHYS_MEM_ACCESS_PROT
+struct file;
+extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
+				     unsigned long size, pgprot_t vma_prot);
+
+/*
+ * 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_UNCACHED | _PAGE_SO;
+
+	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_UNCACHED;
+
+	return __pgprot(prot);
+}
+
+/*
+ * 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)));
+}
+
+/* to find an entry in a page-table-directory */
+static inline pgd_t *pgd_offset(struct mm_struct *mm, unsigned long address)
+{
+	return mm->pgd + pgd_index(address);
+}
+
+/* Find an entry in the third-level page table.. */
+static inline pte_t *pte_offset(pmd_t *dir, unsigned long address)
+{
+	return (pte_t *) (pmd_page_vaddr(*dir)) +
+		((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1));
+}
+
+extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
+extern void paging_init(void);
+
+void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
+		      pte_t *pte);
+
+/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
+#define kern_addr_valid(addr)	(1)
+
+#define io_remap_pfn_range(vma, vaddr, pfn, size, prot) \
+	remap_pfn_range(vma, vaddr, pfn, size, prot)
+
+#include <asm-generic/pgtable.h>
+
+#endif /* __ASM_CSKY_PGTABLE_H */
diff --git a/arch/csky/include/asm/processor.h b/arch/csky/include/asm/processor.h
new file mode 100644
index 0000000..21e0bd5
--- /dev/null
+++ b/arch/csky/include/asm/processor.h
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_PROCESSOR_H
+#define __ASM_CSKY_PROCESSOR_H
+
+#include <linux/bitops.h>
+#include <asm/segment.h>
+#include <asm/ptrace.h>
+#include <asm/current.h>
+#include <asm/cache.h>
+#include <abi/reg_ops.h>
+#include <abi/regdef.h>
+#include <abi/switch_context.h>
+#ifdef CONFIG_CPU_HAS_FPU
+#include <abi/fpu.h>
+#endif
+
+struct cpuinfo_csky {
+	unsigned long asid_cache;
+} __aligned(SMP_CACHE_BYTES);
+
+extern struct cpuinfo_csky cpu_data[];
+
+/*
+ * User space process size: 2GB. This is hardcoded into a few places,
+ * so don't change it unless you know what you are doing.  TASK_SIZE
+ * for a 64 bit kernel expandable to 8192EB, of which the current CSKY
+ * implementations will "only" be able to use 1TB ...
+ */
+#define TASK_SIZE       0x7fff8000UL
+
+#ifdef __KERNEL__
+#define STACK_TOP       TASK_SIZE
+#define STACK_TOP_MAX   STACK_TOP
+#endif
+
+/* This decides where the kernel will search for a free chunk of vm
+ * space during mmap's.
+ */
+#define TASK_UNMAPPED_BASE      (TASK_SIZE / 3)
+
+struct thread_struct {
+	unsigned long  ksp;       /* kernel stack pointer */
+	unsigned long  sr;        /* saved status register */
+
+	/* FPU regs */
+	struct user_fp __aligned(16) user_fp;
+};
+
+#define INIT_THREAD  { \
+	.ksp = sizeof(init_stack) + (unsigned long) &init_stack, \
+	.sr = DEFAULT_PSR_VALUE, \
+}
+
+/*
+ * Do necessary setup to start up a newly executed thread.
+ *
+ * pass the data segment into user programs if it exists,
+ * it can't hurt anything as far as I can tell
+ */
+#define start_thread(_regs, _pc, _usp)					\
+do {									\
+	set_fs(USER_DS); /* reads from user space */			\
+	(_regs)->pc = (_pc);						\
+	(_regs)->regs[1] = 0; /* ABIV1 is R7, uClibc_main rtdl arg */	\
+	(_regs)->regs[2] = 0;						\
+	(_regs)->regs[3] = 0; /* ABIV2 is R7, use it? */		\
+	(_regs)->sr &= ~PS_S;						\
+	(_regs)->usp = (_usp);						\
+} while (0)
+
+/* Forward declaration, a strange C thing */
+struct task_struct;
+
+/* Free all resources held by a thread. */
+static inline void release_thread(struct task_struct *dead_task)
+{
+}
+
+/* Prepare to copy thread state - unlazy all lazy status */
+#define prepare_to_copy(tsk)    do { } while (0)
+
+extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
+
+#define copy_segments(tsk, mm)		do { } while (0)
+#define release_segments(mm)		do { } while (0)
+#define forget_segments()		do { } while (0)
+
+extern unsigned long thread_saved_pc(struct task_struct *tsk);
+
+unsigned long get_wchan(struct task_struct *p);
+
+#define KSTK_EIP(tsk)		(task_pt_regs(tsk)->pc)
+#define KSTK_ESP(tsk)		(task_pt_regs(tsk)->usp)
+
+#define task_pt_regs(p) \
+	((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
+
+#define cpu_relax() barrier()
+
+#endif /* __ASM_CSKY_PROCESSOR_H */
diff --git a/arch/csky/include/asm/ptrace.h b/arch/csky/include/asm/ptrace.h
new file mode 100644
index 0000000..d0aba7b
--- /dev/null
+++ b/arch/csky/include/asm/ptrace.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_PTRACE_H
+#define __ASM_CSKY_PTRACE_H
+
+#include <uapi/asm/ptrace.h>
+#include <asm/traps.h>
+#include <linux/types.h>
+
+#ifndef __ASSEMBLY__
+
+#define PS_S	0x80000000 /* Supervisor Mode */
+
+#define arch_has_single_step() (1)
+#define current_pt_regs() \
+({ (struct pt_regs *)((char *)current_thread_info() + THREAD_SIZE) - 1; })
+
+#define user_stack_pointer(regs) ((regs)->usp)
+
+#define user_mode(regs) (!((regs)->sr & PS_S))
+#define instruction_pointer(regs) ((regs)->pc)
+#define profile_pc(regs) instruction_pointer(regs)
+
+static inline bool in_syscall(struct pt_regs const *regs)
+{
+	return ((regs->sr >> 16) & 0xff) == VEC_TRAP0;
+}
+
+static inline void forget_syscall(struct pt_regs *regs)
+{
+	regs->sr &= ~(0xff << 16);
+}
+
+static inline unsigned long regs_return_value(struct pt_regs *regs)
+{
+	return regs->a0;
+}
+
+#endif /* __ASSEMBLY__ */
+#endif /* __ASM_CSKY_PTRACE_H */
diff --git a/arch/csky/include/asm/reg_ops.h b/arch/csky/include/asm/reg_ops.h
new file mode 100644
index 0000000..cccf7d5
--- /dev/null
+++ b/arch/csky/include/asm/reg_ops.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_REGS_OPS_H
+#define __ASM_REGS_OPS_H
+
+#define mfcr(reg)		\
+({				\
+	unsigned int tmp;	\
+	asm volatile(		\
+	"mfcr %0, "reg"\n"	\
+	: "=r"(tmp)		\
+	:			\
+	: "memory");		\
+	tmp;			\
+})
+
+#define mtcr(reg, val)		\
+({				\
+	asm volatile(		\
+	"mtcr %0, "reg"\n"	\
+	:			\
+	: "r"(val)		\
+	: "memory");		\
+})
+
+#endif /* __ASM_REGS_OPS_H */
diff --git a/arch/csky/include/asm/segment.h b/arch/csky/include/asm/segment.h
new file mode 100644
index 0000000..db2640d
--- /dev/null
+++ b/arch/csky/include/asm/segment.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_SEGMENT_H
+#define __ASM_CSKY_SEGMENT_H
+
+typedef struct {
+	unsigned long seg;
+} mm_segment_t;
+
+#define KERNEL_DS		((mm_segment_t) { 0xFFFFFFFF })
+
+#define USER_DS			((mm_segment_t) { 0x80000000UL })
+#define get_fs()		(current_thread_info()->addr_limit)
+#define set_fs(x)		(current_thread_info()->addr_limit = (x))
+#define segment_eq(a, b)	((a).seg == (b).seg)
+
+#endif /* __ASM_CSKY_SEGMENT_H */
diff --git a/arch/csky/include/asm/shmparam.h b/arch/csky/include/asm/shmparam.h
new file mode 100644
index 0000000..efafe4c
--- /dev/null
+++ b/arch/csky/include/asm/shmparam.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_SHMPARAM_H
+#define __ASM_CSKY_SHMPARAM_H
+
+#define SHMLBA	(4 * PAGE_SIZE)
+
+#define __ARCH_FORCE_SHMLBA
+
+#endif /* __ASM_CSKY_SHMPARAM_H */
diff --git a/arch/csky/include/asm/smp.h b/arch/csky/include/asm/smp.h
new file mode 100644
index 0000000..668b79c
--- /dev/null
+++ b/arch/csky/include/asm/smp.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_SMP_H
+#define __ASM_CSKY_SMP_H
+
+#include <linux/cpumask.h>
+#include <linux/irqreturn.h>
+#include <linux/threads.h>
+
+#ifdef CONFIG_SMP
+
+void __init setup_smp(void);
+
+void __init setup_smp_ipi(void);
+
+void arch_send_call_function_ipi_mask(struct cpumask *mask);
+
+void arch_send_call_function_single_ipi(int cpu);
+
+void __init set_send_ipi(void (*func)(const struct cpumask *mask), int irq);
+
+#define raw_smp_processor_id()	(current_thread_info()->cpu)
+
+int __cpu_disable(void);
+
+void __cpu_die(unsigned int cpu);
+
+#endif /* CONFIG_SMP */
+
+#endif /* __ASM_CSKY_SMP_H */
diff --git a/arch/csky/include/asm/spinlock.h b/arch/csky/include/asm/spinlock.h
new file mode 100644
index 0000000..7cf3f2b
--- /dev/null
+++ b/arch/csky/include/asm/spinlock.h
@@ -0,0 +1,256 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_SPINLOCK_H
+#define __ASM_CSKY_SPINLOCK_H
+
+#include <linux/spinlock_types.h>
+#include <asm/barrier.h>
+
+#ifdef CONFIG_QUEUED_RWLOCKS
+
+/*
+ * Ticket-based spin-locking.
+ */
+static inline void arch_spin_lock(arch_spinlock_t *lock)
+{
+	arch_spinlock_t lockval;
+	u32 ticket_next = 1 << TICKET_NEXT;
+	u32 *p = &lock->lock;
+	u32 tmp;
+
+	asm volatile (
+		"1:	ldex.w		%0, (%2) \n"
+		"	mov		%1, %0	 \n"
+		"	add		%0, %3	 \n"
+		"	stex.w		%0, (%2) \n"
+		"	bez		%0, 1b   \n"
+		: "=&r" (tmp), "=&r" (lockval)
+		: "r"(p), "r"(ticket_next)
+		: "cc");
+
+	while (lockval.tickets.next != lockval.tickets.owner)
+		lockval.tickets.owner = READ_ONCE(lock->tickets.owner);
+
+	smp_mb();
+}
+
+static inline int arch_spin_trylock(arch_spinlock_t *lock)
+{
+	u32 tmp, contended, res;
+	u32 ticket_next = 1 << TICKET_NEXT;
+	u32 *p = &lock->lock;
+
+	do {
+		asm volatile (
+		"	ldex.w		%0, (%3)   \n"
+		"	movi		%2, 1	   \n"
+		"	rotli		%1, %0, 16 \n"
+		"	cmpne		%1, %0     \n"
+		"	bt		1f         \n"
+		"	movi		%2, 0	   \n"
+		"	add		%0, %0, %4 \n"
+		"	stex.w		%0, (%3)   \n"
+		"1:				   \n"
+		: "=&r" (res), "=&r" (tmp), "=&r" (contended)
+		: "r"(p), "r"(ticket_next)
+		: "cc");
+	} while (!res);
+
+	if (!contended)
+		smp_mb();
+
+	return !contended;
+}
+
+static inline void arch_spin_unlock(arch_spinlock_t *lock)
+{
+	smp_mb();
+	WRITE_ONCE(lock->tickets.owner, lock->tickets.owner + 1);
+}
+
+static inline int arch_spin_value_unlocked(arch_spinlock_t lock)
+{
+	return lock.tickets.owner == lock.tickets.next;
+}
+
+static inline int arch_spin_is_locked(arch_spinlock_t *lock)
+{
+	return !arch_spin_value_unlocked(READ_ONCE(*lock));
+}
+
+static inline int arch_spin_is_contended(arch_spinlock_t *lock)
+{
+	struct __raw_tickets tickets = READ_ONCE(lock->tickets);
+
+	return (tickets.next - tickets.owner) > 1;
+}
+#define arch_spin_is_contended	arch_spin_is_contended
+
+#include <asm/qrwlock.h>
+
+/* See include/linux/spinlock.h */
+#define smp_mb__after_spinlock()	smp_mb()
+
+#else /* CONFIG_QUEUED_RWLOCKS */
+
+/*
+ * Test-and-set spin-locking.
+ */
+static inline void arch_spin_lock(arch_spinlock_t *lock)
+{
+	u32 *p = &lock->lock;
+	u32 tmp;
+
+	asm volatile (
+		"1:	ldex.w		%0, (%1) \n"
+		"	bnez		%0, 1b   \n"
+		"	movi		%0, 1    \n"
+		"	stex.w		%0, (%1) \n"
+		"	bez		%0, 1b   \n"
+		: "=&r" (tmp)
+		: "r"(p)
+		: "cc");
+	smp_mb();
+}
+
+static inline void arch_spin_unlock(arch_spinlock_t *lock)
+{
+	smp_mb();
+	WRITE_ONCE(lock->lock, 0);
+}
+
+static inline int arch_spin_trylock(arch_spinlock_t *lock)
+{
+	u32 *p = &lock->lock;
+	u32 tmp;
+
+	asm volatile (
+		"1:	ldex.w		%0, (%1) \n"
+		"	bnez		%0, 2f   \n"
+		"	movi		%0, 1    \n"
+		"	stex.w		%0, (%1) \n"
+		"	bez		%0, 1b   \n"
+		"	movi		%0, 0    \n"
+		"2:				 \n"
+		: "=&r" (tmp)
+		: "r"(p)
+		: "cc");
+
+	if (!tmp)
+		smp_mb();
+
+	return !tmp;
+}
+
+#define arch_spin_is_locked(x)	(READ_ONCE((x)->lock) != 0)
+
+/*
+ * read lock/unlock/trylock
+ */
+static inline void arch_read_lock(arch_rwlock_t *lock)
+{
+	u32 *p = &lock->lock;
+	u32 tmp;
+
+	asm volatile (
+		"1:	ldex.w		%0, (%1) \n"
+		"	blz		%0, 1b   \n"
+		"	addi		%0, 1    \n"
+		"	stex.w		%0, (%1) \n"
+		"	bez		%0, 1b   \n"
+		: "=&r" (tmp)
+		: "r"(p)
+		: "cc");
+	smp_mb();
+}
+
+static inline void arch_read_unlock(arch_rwlock_t *lock)
+{
+	u32 *p = &lock->lock;
+	u32 tmp;
+
+	smp_mb();
+	asm volatile (
+		"1:	ldex.w		%0, (%1) \n"
+		"	subi		%0, 1    \n"
+		"	stex.w		%0, (%1) \n"
+		"	bez		%0, 1b   \n"
+		: "=&r" (tmp)
+		: "r"(p)
+		: "cc");
+}
+
+static inline int arch_read_trylock(arch_rwlock_t *lock)
+{
+	u32 *p = &lock->lock;
+	u32 tmp;
+
+	asm volatile (
+		"1:	ldex.w		%0, (%1) \n"
+		"	blz		%0, 2f   \n"
+		"	addi		%0, 1    \n"
+		"	stex.w		%0, (%1) \n"
+		"	bez		%0, 1b   \n"
+		"	movi		%0, 0    \n"
+		"2:				 \n"
+		: "=&r" (tmp)
+		: "r"(p)
+		: "cc");
+
+	if (!tmp)
+		smp_mb();
+
+	return !tmp;
+}
+
+/*
+ * write lock/unlock/trylock
+ */
+static inline void arch_write_lock(arch_rwlock_t *lock)
+{
+	u32 *p = &lock->lock;
+	u32 tmp;
+
+	asm volatile (
+		"1:	ldex.w		%0, (%1) \n"
+		"	bnez		%0, 1b   \n"
+		"	subi		%0, 1    \n"
+		"	stex.w		%0, (%1) \n"
+		"	bez		%0, 1b   \n"
+		: "=&r" (tmp)
+		: "r"(p)
+		: "cc");
+	smp_mb();
+}
+
+static inline void arch_write_unlock(arch_rwlock_t *lock)
+{
+	smp_mb();
+	WRITE_ONCE(lock->lock, 0);
+}
+
+static inline int arch_write_trylock(arch_rwlock_t *lock)
+{
+	u32 *p = &lock->lock;
+	u32 tmp;
+
+	asm volatile (
+		"1:	ldex.w		%0, (%1) \n"
+		"	bnez		%0, 2f   \n"
+		"	subi		%0, 1    \n"
+		"	stex.w		%0, (%1) \n"
+		"	bez		%0, 1b   \n"
+		"	movi		%0, 0    \n"
+		"2:				 \n"
+		: "=&r" (tmp)
+		: "r"(p)
+		: "cc");
+
+	if (!tmp)
+		smp_mb();
+
+	return !tmp;
+}
+
+#endif /* CONFIG_QUEUED_RWLOCKS */
+#endif /* __ASM_CSKY_SPINLOCK_H */
diff --git a/arch/csky/include/asm/spinlock_types.h b/arch/csky/include/asm/spinlock_types.h
new file mode 100644
index 0000000..88b8243
--- /dev/null
+++ b/arch/csky/include/asm/spinlock_types.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_SPINLOCK_TYPES_H
+#define __ASM_CSKY_SPINLOCK_TYPES_H
+
+#ifndef __LINUX_SPINLOCK_TYPES_H
+# error "please don't include this file directly"
+#endif
+
+#define TICKET_NEXT	16
+
+typedef struct {
+	union {
+		u32 lock;
+		struct __raw_tickets {
+			/* little endian */
+			u16 owner;
+			u16 next;
+		} tickets;
+	};
+} arch_spinlock_t;
+
+#define __ARCH_SPIN_LOCK_UNLOCKED	{ { 0 } }
+
+#ifdef CONFIG_QUEUED_RWLOCKS
+#include <asm-generic/qrwlock_types.h>
+
+#else /* CONFIG_NR_CPUS > 2 */
+
+typedef struct {
+	u32 lock;
+} arch_rwlock_t;
+
+#define __ARCH_RW_LOCK_UNLOCKED		{ 0 }
+
+#endif /* CONFIG_QUEUED_RWLOCKS */
+#endif /* __ASM_CSKY_SPINLOCK_TYPES_H */
diff --git a/arch/csky/include/asm/string.h b/arch/csky/include/asm/string.h
new file mode 100644
index 0000000..73142de
--- /dev/null
+++ b/arch/csky/include/asm/string.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef _CSKY_STRING_MM_H_
+#define _CSKY_STRING_MM_H_
+
+#ifndef __ASSEMBLY__
+#include <linux/types.h>
+#include <linux/compiler.h>
+#include <abi/string.h>
+#endif
+
+#endif /* _CSKY_STRING_MM_H_ */
diff --git a/arch/csky/include/asm/switch_to.h b/arch/csky/include/asm/switch_to.h
new file mode 100644
index 0000000..35a39e8
--- /dev/null
+++ b/arch/csky/include/asm/switch_to.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_SWITCH_TO_H
+#define __ASM_CSKY_SWITCH_TO_H
+
+#include <linux/thread_info.h>
+#ifdef CONFIG_CPU_HAS_FPU
+#include <abi/fpu.h>
+static inline void __switch_to_fpu(struct task_struct *prev,
+				   struct task_struct *next)
+{
+	save_to_user_fp(&prev->thread.user_fp);
+	restore_from_user_fp(&next->thread.user_fp);
+}
+#else
+static inline void __switch_to_fpu(struct task_struct *prev,
+				   struct task_struct *next)
+{}
+#endif
+
+/*
+ * Context switching is now performed out-of-line in switch_to.S
+ */
+extern struct task_struct *__switch_to(struct task_struct *,
+				       struct task_struct *);
+
+#define switch_to(prev, next, last)					\
+	do {								\
+		struct task_struct *__prev = (prev);			\
+		struct task_struct *__next = (next);			\
+		__switch_to_fpu(__prev, __next);			\
+		((last) = __switch_to((prev), (next)));			\
+	} while (0)
+
+#endif /* __ASM_CSKY_SWITCH_TO_H */
diff --git a/arch/csky/include/asm/syscall.h b/arch/csky/include/asm/syscall.h
new file mode 100644
index 0000000..f624fa3
--- /dev/null
+++ b/arch/csky/include/asm/syscall.h
@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_SYSCALL_H
+#define __ASM_SYSCALL_H
+
+#include <linux/sched.h>
+#include <linux/err.h>
+#include <abi/regdef.h>
+#include <uapi/linux/audit.h>
+
+extern void *sys_call_table[];
+
+static inline int
+syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
+{
+	return regs_syscallid(regs);
+}
+
+static inline void
+syscall_set_nr(struct task_struct *task, struct pt_regs *regs,
+	       int sysno)
+{
+	regs_syscallid(regs) = sysno;
+}
+
+static inline void
+syscall_rollback(struct task_struct *task, struct pt_regs *regs)
+{
+	regs->a0 = regs->orig_a0;
+}
+
+static inline long
+syscall_get_error(struct task_struct *task, struct pt_regs *regs)
+{
+	unsigned long error = regs->a0;
+
+	return IS_ERR_VALUE(error) ? error : 0;
+}
+
+static inline long
+syscall_get_return_value(struct task_struct *task, struct pt_regs *regs)
+{
+	return regs->a0;
+}
+
+static inline void
+syscall_set_return_value(struct task_struct *task, struct pt_regs *regs,
+		int error, long val)
+{
+	regs->a0 = (long) error ?: val;
+}
+
+static inline void
+syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
+		      unsigned long *args)
+{
+	args[0] = regs->orig_a0;
+	args++;
+	memcpy(args, &regs->a1, 5 * sizeof(args[0]));
+}
+
+static inline void
+syscall_set_arguments(struct task_struct *task, struct pt_regs *regs,
+		      const unsigned long *args)
+{
+	regs->orig_a0 = args[0];
+	args++;
+	memcpy(&regs->a1, args, 5 * sizeof(regs->a1));
+}
+
+static inline int
+syscall_get_arch(struct task_struct *task)
+{
+	return AUDIT_ARCH_CSKY;
+}
+
+#endif	/* __ASM_SYSCALL_H */
diff --git a/arch/csky/include/asm/syscalls.h b/arch/csky/include/asm/syscalls.h
new file mode 100644
index 0000000..5d48e5e
--- /dev/null
+++ b/arch/csky/include/asm/syscalls.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_SYSCALLS_H
+#define __ASM_CSKY_SYSCALLS_H
+
+#include <asm-generic/syscalls.h>
+
+long sys_cacheflush(void __user *, unsigned long, int);
+
+long sys_set_thread_area(unsigned long addr);
+
+long sys_csky_fadvise64_64(int fd, int advice, loff_t offset, loff_t len);
+
+#endif /* __ASM_CSKY_SYSCALLS_H */
diff --git a/arch/csky/include/asm/thread_info.h b/arch/csky/include/asm/thread_info.h
new file mode 100644
index 0000000..0b546a5
--- /dev/null
+++ b/arch/csky/include/asm/thread_info.h
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef _ASM_CSKY_THREAD_INFO_H
+#define _ASM_CSKY_THREAD_INFO_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/version.h>
+#include <asm/types.h>
+#include <asm/page.h>
+#include <asm/processor.h>
+#include <abi/switch_context.h>
+
+struct thread_info {
+	struct task_struct	*task;
+	void			*dump_exec_domain;
+	unsigned long		flags;
+	int			preempt_count;
+	unsigned long		tp_value;
+	mm_segment_t		addr_limit;
+	struct restart_block	restart_block;
+	struct pt_regs		*regs;
+	unsigned int		cpu;
+};
+
+#define INIT_THREAD_INFO(tsk)			\
+{						\
+	.task		= &tsk,			\
+	.preempt_count  = INIT_PREEMPT_COUNT,	\
+	.addr_limit     = KERNEL_DS,		\
+	.cpu		= 0,			\
+	.restart_block = {			\
+		.fn = do_no_restart_syscall,	\
+	},					\
+}
+
+#define THREAD_SIZE_ORDER (THREAD_SHIFT - PAGE_SHIFT)
+
+#define thread_saved_fp(tsk) \
+	((unsigned long)(((struct switch_stack *)(tsk->thread.ksp))->r8))
+
+static inline struct thread_info *current_thread_info(void)
+{
+	unsigned long sp;
+
+	asm volatile("mov %0, sp\n":"=r"(sp));
+
+	return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
+}
+
+#endif /* !__ASSEMBLY__ */
+
+#define TIF_SIGPENDING		0	/* signal pending */
+#define TIF_NOTIFY_RESUME	1       /* callback before returning to user */
+#define TIF_NEED_RESCHED	2	/* rescheduling necessary */
+#define TIF_SYSCALL_TRACE	3	/* syscall trace active */
+#define TIF_SYSCALL_TRACEPOINT	4       /* syscall tracepoint instrumentation */
+#define TIF_SYSCALL_AUDIT	5	/* syscall auditing */
+#define TIF_POLLING_NRFLAG	16	/* poll_idle() is TIF_NEED_RESCHED */
+#define TIF_MEMDIE		18      /* is terminating due to OOM killer */
+#define TIF_RESTORE_SIGMASK	20	/* restore signal mask in do_signal() */
+#define TIF_SECCOMP		21	/* secure computing */
+
+#define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
+#define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
+#define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
+#define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
+#define _TIF_SYSCALL_TRACEPOINT	(1 << TIF_SYSCALL_TRACEPOINT)
+#define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)
+#define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)
+#define _TIF_MEMDIE		(1 << TIF_MEMDIE)
+#define _TIF_RESTORE_SIGMASK	(1 << TIF_RESTORE_SIGMASK)
+#define _TIF_SECCOMP		(1 << TIF_SECCOMP)
+
+#endif	/* _ASM_CSKY_THREAD_INFO_H */
diff --git a/arch/csky/include/asm/tlb.h b/arch/csky/include/asm/tlb.h
new file mode 100644
index 0000000..fdff9b8
--- /dev/null
+++ b/arch/csky/include/asm/tlb.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_TLB_H
+#define __ASM_CSKY_TLB_H
+
+#include <asm/cacheflush.h>
+
+#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 { \
+		if (!(tlb)->fullmm) \
+			flush_tlb_range(vma, (vma)->vm_start, (vma)->vm_end); \
+	}  while (0)
+
+#define tlb_flush(tlb) flush_tlb_mm((tlb)->mm)
+
+#include <asm-generic/tlb.h>
+
+#endif /* __ASM_CSKY_TLB_H */
diff --git a/arch/csky/include/asm/tlbflush.h b/arch/csky/include/asm/tlbflush.h
new file mode 100644
index 0000000..6845b06
--- /dev/null
+++ b/arch/csky/include/asm/tlbflush.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_TLBFLUSH_H
+#define __ASM_TLBFLUSH_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 flush_tlb_all(void);
+extern void flush_tlb_mm(struct mm_struct *mm);
+extern void flush_tlb_page(struct vm_area_struct *vma, unsigned long page);
+extern void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
+			    unsigned long end);
+extern void flush_tlb_kernel_range(unsigned long start, unsigned long end);
+
+extern void flush_tlb_one(unsigned long vaddr);
+
+#endif
diff --git a/arch/csky/include/asm/traps.h b/arch/csky/include/asm/traps.h
new file mode 100644
index 0000000..1c08180
--- /dev/null
+++ b/arch/csky/include/asm/traps.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_TRAPS_H
+#define __ASM_CSKY_TRAPS_H
+
+#define VEC_RESET	0
+#define VEC_ALIGN	1
+#define VEC_ACCESS	2
+#define VEC_ZERODIV	3
+#define VEC_ILLEGAL	4
+#define VEC_PRIV	5
+#define VEC_TRACE	6
+#define VEC_BREAKPOINT	7
+#define VEC_UNRECOVER	8
+#define VEC_SOFTRESET	9
+#define VEC_AUTOVEC	10
+#define VEC_FAUTOVEC	11
+#define VEC_HWACCEL	12
+
+#define	VEC_TLBMISS	14
+#define	VEC_TLBMODIFIED	15
+
+#define VEC_TRAP0	16
+#define VEC_TRAP1	17
+#define VEC_TRAP2	18
+#define VEC_TRAP3	19
+
+#define	VEC_TLBINVALIDL	20
+#define	VEC_TLBINVALIDS	21
+
+#define VEC_PRFL	29
+#define VEC_FPE		30
+
+extern void *vec_base[];
+
+#define VEC_INIT(i, func) \
+do { \
+	vec_base[i] = (void *)func; \
+} while (0)
+
+void csky_alignment(struct pt_regs *regs);
+
+#endif /* __ASM_CSKY_TRAPS_H */
diff --git a/arch/csky/include/asm/uaccess.h b/arch/csky/include/asm/uaccess.h
new file mode 100644
index 0000000..eaa1c34
--- /dev/null
+++ b/arch/csky/include/asm/uaccess.h
@@ -0,0 +1,408 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_UACCESS_H
+#define __ASM_CSKY_UACCESS_H
+
+/*
+ * User space memory access functions
+ */
+#include <linux/compiler.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/version.h>
+#include <asm/segment.h>
+
+static inline int access_ok(const void *addr, unsigned long size)
+{
+	unsigned long limit = current_thread_info()->addr_limit.seg;
+
+	return (((unsigned long)addr < limit) &&
+		((unsigned long)(addr + size) < limit));
+}
+
+#define __addr_ok(addr) (access_ok(addr, 0))
+
+extern int __put_user_bad(void);
+
+/*
+ * Tell gcc we read from memory instead of writing: this is because
+ * we do not write to any memory gcc knows about, so there are no
+ * aliasing issues.
+ */
+
+/*
+ * These are the main single-value transfer routines.  They automatically
+ * use the right size if we just have the right pointer type.
+ *
+ * This gets kind of ugly. We want to return _two_ values in "get_user()"
+ * and yet we don't want to do any pointers, because that is too much
+ * of a performance impact. Thus we have a few rather ugly macros here,
+ * and hide all the ugliness from the user.
+ *
+ * The "__xxx" versions of the user access functions are versions that
+ * do not verify the address space, that must have been done previously
+ * with a separate "access_ok()" call (this is used when we do multiple
+ * accesses to the same area of user memory).
+ *
+ * As we use the same address space for kernel and user data on
+ * Ckcore, we can just do these as direct assignments.  (Of course, the
+ * exception handling means that it's no longer "just"...)
+ */
+
+#define put_user(x, ptr) \
+	__put_user_check((x), (ptr), sizeof(*(ptr)))
+
+#define __put_user(x, ptr) \
+	__put_user_nocheck((x), (ptr), sizeof(*(ptr)))
+
+#define __ptr(x) ((unsigned long *)(x))
+
+#define get_user(x, ptr) \
+	__get_user_check((x), (ptr), sizeof(*(ptr)))
+
+#define __get_user(x, ptr) \
+	__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
+
+#define __put_user_nocheck(x, ptr, size)				\
+({									\
+	long __pu_err = 0;						\
+	typeof(*(ptr)) *__pu_addr = (ptr);				\
+	typeof(*(ptr)) __pu_val = (typeof(*(ptr)))(x);			\
+	if (__pu_addr)							\
+		__put_user_size(__pu_val, (__pu_addr), (size),		\
+				__pu_err);				\
+	__pu_err;							\
+})
+
+#define __put_user_check(x, ptr, size)					\
+({									\
+	long __pu_err = -EFAULT;					\
+	typeof(*(ptr)) *__pu_addr = (ptr);				\
+	typeof(*(ptr)) __pu_val = (typeof(*(ptr)))(x);			\
+	if (access_ok(__pu_addr, size) && __pu_addr)	\
+		__put_user_size(__pu_val, __pu_addr, (size), __pu_err);	\
+	__pu_err;							\
+})
+
+#define __put_user_size(x, ptr, size, retval)		\
+do {							\
+	retval = 0;					\
+	switch (size) {                                 \
+	case 1:						\
+		__put_user_asm_b(x, ptr, retval);	\
+		break;					\
+	case 2:						\
+		__put_user_asm_h(x, ptr, retval);	\
+		break;					\
+	case 4:						\
+		__put_user_asm_w(x, ptr, retval);	\
+		break;					\
+	case 8:						\
+		__put_user_asm_64(x, ptr, retval);	\
+		break;					\
+	default:					\
+		__put_user_bad();			\
+	}	                                        \
+} while (0)
+
+/*
+ * We don't tell gcc that we are accessing memory, but this is OK
+ * because we do not write to any memory gcc knows about, so there
+ * are no aliasing issues.
+ *
+ * Note that PC at a fault is the address *after* the faulting
+ * instruction.
+ */
+#define __put_user_asm_b(x, ptr, err)			\
+do {							\
+	int errcode;					\
+	asm volatile(					\
+	"1:     stb   %1, (%2,0)	\n"		\
+	"       br    3f		\n"		\
+	"2:     mov   %0, %3		\n"		\
+	"       br    3f		\n"		\
+	".section __ex_table, \"a\"	\n"		\
+	".align   2			\n"		\
+	".long    1b,2b			\n"		\
+	".previous			\n"		\
+	"3:				\n"		\
+	: "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode)	\
+	: "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT)	\
+	: "memory");					\
+} while (0)
+
+#define __put_user_asm_h(x, ptr, err)			\
+do {							\
+	int errcode;					\
+	asm volatile(					\
+	"1:     sth   %1, (%2,0)	\n"		\
+	"       br    3f		\n"		\
+	"2:     mov   %0, %3		\n"		\
+	"       br    3f		\n"		\
+	".section __ex_table, \"a\"	\n"		\
+	".align   2			\n"		\
+	".long    1b,2b			\n"		\
+	".previous			\n"		\
+	"3:				\n"		\
+	: "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode)	\
+	: "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT)	\
+	: "memory");					\
+} while (0)
+
+#define __put_user_asm_w(x, ptr, err)			\
+do {							\
+	int errcode;					\
+	asm volatile(					\
+	"1:     stw   %1, (%2,0)	\n"		\
+	"       br    3f		\n"		\
+	"2:     mov   %0, %3		\n"		\
+	"       br    3f		\n"		\
+	".section __ex_table,\"a\"	\n"		\
+	".align   2			\n"		\
+	".long    1b, 2b		\n"		\
+	".previous			\n"		\
+	"3:				\n"		\
+	: "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode)	\
+	: "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT)	\
+	: "memory");					\
+} while (0)
+
+#define __put_user_asm_64(x, ptr, err)				\
+do {								\
+	int tmp;						\
+	int errcode;						\
+	typeof(*(ptr))src = (typeof(*(ptr)))x;			\
+	typeof(*(ptr))*psrc = &src;				\
+								\
+	asm volatile(						\
+	"     ldw     %3, (%1, 0)     \n"			\
+	"1:   stw     %3, (%2, 0)     \n"			\
+	"     ldw     %3, (%1, 4)     \n"			\
+	"2:   stw     %3, (%2, 4)     \n"			\
+	"     br      4f              \n"			\
+	"3:   mov     %0, %4          \n"			\
+	"     br      4f              \n"			\
+	".section __ex_table, \"a\"   \n"			\
+	".align   2                   \n"			\
+	".long    1b, 3b              \n"			\
+	".long    2b, 3b              \n"			\
+	".previous                    \n"			\
+	"4:                           \n"			\
+	: "=r"(err), "=r"(psrc), "=r"(ptr),			\
+	  "=r"(tmp), "=r"(errcode)				\
+	: "0"(err), "1"(psrc), "2"(ptr), "3"(0), "4"(-EFAULT)	\
+	: "memory");						\
+} while (0)
+
+#define __get_user_nocheck(x, ptr, size)			\
+({								\
+	long  __gu_err;						\
+	__get_user_size(x, (ptr), (size), __gu_err);		\
+	__gu_err;						\
+})
+
+#define __get_user_check(x, ptr, size)				\
+({								\
+	int __gu_err = -EFAULT;					\
+	const __typeof__(*(ptr)) __user *__gu_ptr = (ptr);	\
+	if (access_ok(__gu_ptr, size) && __gu_ptr)	\
+		__get_user_size(x, __gu_ptr, size, __gu_err);	\
+	__gu_err;						\
+})
+
+#define __get_user_size(x, ptr, size, retval)			\
+do {								\
+	switch (size) {						\
+	case 1:							\
+		__get_user_asm_common((x), ptr, "ldb", retval);	\
+		break;						\
+	case 2:							\
+		__get_user_asm_common((x), ptr, "ldh", retval);	\
+		break;						\
+	case 4:							\
+		__get_user_asm_common((x), ptr, "ldw", retval);	\
+		break;						\
+	default:						\
+		x = 0;						\
+		(retval) = __get_user_bad();			\
+	}							\
+} while (0)
+
+#define __get_user_asm_common(x, ptr, ins, err)			\
+do {								\
+	int errcode;						\
+	asm volatile(						\
+	"1:   " ins " %1, (%4,0)	\n"			\
+	"       br    3f		\n"			\
+	/* Fix up codes */					\
+	"2:     mov   %0, %2		\n"			\
+	"       movi  %1, 0		\n"			\
+	"       br    3f		\n"			\
+	".section __ex_table,\"a\"      \n"			\
+	".align   2			\n"			\
+	".long    1b, 2b		\n"			\
+	".previous			\n"			\
+	"3:				\n" 			\
+	: "=r"(err), "=r"(x), "=r"(errcode)			\
+	: "0"(0), "r"(ptr), "2"(-EFAULT)			\
+	: "memory");						\
+} while (0)
+
+extern int __get_user_bad(void);
+
+#define __copy_user(to, from, n)			\
+do {							\
+	int w0, w1, w2, w3;				\
+	asm volatile(					\
+	"0:     cmpnei  %1, 0           \n"		\
+	"       bf      8f              \n"		\
+	"       mov     %3, %1          \n"		\
+	"       or      %3, %2          \n"		\
+	"       andi    %3, 3           \n"		\
+	"       cmpnei  %3, 0           \n"		\
+	"       bf      1f              \n"		\
+	"       br      5f              \n"		\
+	"1:     cmplti  %0, 16          \n" /* 4W */	\
+	"       bt      3f              \n"		\
+	"       ldw     %3, (%2, 0)     \n"		\
+	"       ldw     %4, (%2, 4)     \n"		\
+	"       ldw     %5, (%2, 8)     \n"		\
+	"       ldw     %6, (%2, 12)    \n"		\
+	"2:     stw     %3, (%1, 0)     \n"		\
+	"9:     stw     %4, (%1, 4)     \n"		\
+	"10:    stw     %5, (%1, 8)     \n"		\
+	"11:    stw     %6, (%1, 12)    \n"		\
+	"       addi    %2, 16          \n"		\
+	"       addi    %1, 16          \n"		\
+	"       subi    %0, 16          \n"		\
+	"       br      1b              \n"		\
+	"3:     cmplti  %0, 4           \n" /* 1W */	\
+	"       bt      5f              \n"		\
+	"       ldw     %3, (%2, 0)     \n"		\
+	"4:     stw     %3, (%1, 0)     \n"		\
+	"       addi    %2, 4           \n"		\
+	"       addi    %1, 4           \n"		\
+	"       subi    %0, 4           \n"		\
+	"       br      3b              \n"		\
+	"5:     cmpnei  %0, 0           \n"  /* 1B */   \
+	"       bf      8f              \n"		\
+	"       ldb     %3, (%2, 0)     \n"		\
+	"6:     stb     %3, (%1, 0)     \n"		\
+	"       addi    %2,  1          \n"		\
+	"       addi    %1,  1          \n"		\
+	"       subi    %0,  1          \n"		\
+	"       br      5b              \n"		\
+	"7:     br      8f              \n"		\
+	".section __ex_table, \"a\"     \n"		\
+	".align   2                     \n"		\
+	".long    2b, 7b                \n"		\
+	".long    9b, 7b                \n"		\
+	".long   10b, 7b                \n"		\
+	".long   11b, 7b                \n"		\
+	".long    4b, 7b                \n"		\
+	".long    6b, 7b                \n"		\
+	".previous                      \n"		\
+	"8:                             \n"		\
+	: "=r"(n), "=r"(to), "=r"(from), "=r"(w0),	\
+	  "=r"(w1), "=r"(w2), "=r"(w3)			\
+	: "0"(n), "1"(to), "2"(from)			\
+	: "memory");					\
+} while (0)
+
+#define __copy_user_zeroing(to, from, n)		\
+do {							\
+	int tmp;					\
+	int nsave;					\
+	asm volatile(					\
+	"0:     cmpnei  %1, 0           \n"		\
+	"       bf      7f              \n"		\
+	"       mov     %3, %1          \n"		\
+	"       or      %3, %2          \n"		\
+	"       andi    %3, 3           \n"		\
+	"       cmpnei  %3, 0           \n"		\
+	"       bf      1f              \n"		\
+	"       br      5f              \n"		\
+	"1:     cmplti  %0, 16          \n"		\
+	"       bt      3f              \n"		\
+	"2:     ldw     %3, (%2, 0)     \n"		\
+	"10:    ldw     %4, (%2, 4)     \n"		\
+	"       stw     %3, (%1, 0)     \n"		\
+	"       stw     %4, (%1, 4)     \n"		\
+	"11:    ldw     %3, (%2, 8)     \n"		\
+	"12:    ldw     %4, (%2, 12)    \n"		\
+	"       stw     %3, (%1, 8)     \n"		\
+	"       stw     %4, (%1, 12)    \n"		\
+	"       addi    %2, 16          \n"		\
+	"       addi    %1, 16          \n"		\
+	"       subi    %0, 16          \n"		\
+	"       br      1b              \n"		\
+	"3:     cmplti  %0, 4           \n"		\
+	"       bt      5f              \n"		\
+	"4:     ldw     %3, (%2, 0)     \n"		\
+	"       stw     %3, (%1, 0)     \n"		\
+	"       addi    %2, 4           \n"		\
+	"       addi    %1, 4           \n"		\
+	"       subi    %0, 4           \n"		\
+	"       br      3b              \n"		\
+	"5:     cmpnei  %0, 0           \n"		\
+	"       bf      7f              \n"		\
+	"6:     ldb     %3, (%2, 0)     \n"		\
+	"       stb     %3, (%1, 0)     \n"		\
+	"       addi    %2,  1          \n"		\
+	"       addi    %1,  1          \n"		\
+	"       subi    %0,  1          \n"		\
+	"       br      5b              \n"		\
+	"8:     mov     %3, %0          \n"		\
+	"       movi    %4, 0           \n"		\
+	"9:     stb     %4, (%1, 0)     \n"		\
+	"       addi    %1, 1           \n"		\
+	"       subi    %3, 1           \n"		\
+	"       cmpnei  %3, 0           \n"		\
+	"       bt      9b              \n"		\
+	"       br      7f              \n"		\
+	".section __ex_table, \"a\"     \n"		\
+	".align   2                     \n"		\
+	".long    2b, 8b                \n"		\
+	".long   10b, 8b                \n"		\
+	".long   11b, 8b                \n"		\
+	".long   12b, 8b                \n"		\
+	".long    4b, 8b                \n"		\
+	".long    6b, 8b                \n"		\
+	".previous                      \n"		\
+	"7:                             \n"		\
+	: "=r"(n), "=r"(to), "=r"(from), "=r"(nsave),	\
+	  "=r"(tmp)					\
+	: "0"(n), "1"(to), "2"(from)			\
+	: "memory");					\
+} while (0)
+
+unsigned long raw_copy_from_user(void *to, const void *from, unsigned long n);
+unsigned long raw_copy_to_user(void *to, const void *from, unsigned long n);
+
+unsigned long clear_user(void *to, unsigned long n);
+unsigned long __clear_user(void __user *to, unsigned long n);
+
+long strncpy_from_user(char *dst, const char *src, long count);
+long __strncpy_from_user(char *dst, const char *src, long count);
+
+/*
+ * Return the size of a string (including the ending 0)
+ *
+ * Return 0 on exception, a value greater than N if too long
+ */
+long strnlen_user(const char *src, long n);
+
+#define strlen_user(str) strnlen_user(str, 32767)
+
+struct exception_table_entry {
+	unsigned long insn;
+	unsigned long nextinsn;
+};
+
+extern int fixup_exception(struct pt_regs *regs);
+
+#endif /* __ASM_CSKY_UACCESS_H */
diff --git a/arch/csky/include/asm/unistd.h b/arch/csky/include/asm/unistd.h
new file mode 100644
index 0000000..da7a182
--- /dev/null
+++ b/arch/csky/include/asm/unistd.h
@@ -0,0 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <uapi/asm/unistd.h>
+
+#define NR_syscalls (__NR_syscalls)
diff --git a/arch/csky/include/asm/vdso.h b/arch/csky/include/asm/vdso.h
new file mode 100644
index 0000000..d963d69
--- /dev/null
+++ b/arch/csky/include/asm/vdso.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_VDSO_H
+#define __ASM_CSKY_VDSO_H
+
+#include <abi/vdso.h>
+
+struct csky_vdso {
+	unsigned short rt_signal_retcode[4];
+};
+
+#endif /* __ASM_CSKY_VDSO_H */