diff --git a/arch/csky/include/asm/pgtable.h b/arch/csky/include/asm/pgtable.h
index edfcbb25fd9f6998ae09c53b93b229018de03b89..dcea277c09aea8787325abbe50e18e3c467fc993 100644
--- a/arch/csky/include/asm/pgtable.h
+++ b/arch/csky/include/asm/pgtable.h
@@ -45,8 +45,8 @@
 	((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&0x80000000)?__pte(1):__pte(0)))
-#define pte_none(pte)	(!(pte_val(pte)&0xfffffffe))
+	(((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) \
@@ -241,6 +241,11 @@ static inline pte_t pte_mkyoung(pte_t pte)
 
 #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
diff --git a/arch/csky/include/asm/processor.h b/arch/csky/include/asm/processor.h
index 8f454810514f21be1356bd9d763f28e68f8d70b5..21e0bd5293dde27b0b21a9168b2dc62a1e7085d1 100644
--- a/arch/csky/include/asm/processor.h
+++ b/arch/csky/include/asm/processor.h
@@ -49,7 +49,7 @@ struct thread_struct {
 };
 
 #define INIT_THREAD  { \
-	.ksp = (unsigned long) init_thread_union.stack + THREAD_SIZE, \
+	.ksp = sizeof(init_stack) + (unsigned long) &init_stack, \
 	.sr = DEFAULT_PSR_VALUE, \
 }
 
@@ -95,7 +95,7 @@ unsigned long get_wchan(struct task_struct *p);
 #define KSTK_ESP(tsk)		(task_pt_regs(tsk)->usp)
 
 #define task_pt_regs(p) \
-	((struct pt_regs *)(THREAD_SIZE + p->stack) - 1)
+	((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
 
 #define cpu_relax() barrier()
 
diff --git a/arch/csky/kernel/dumpstack.c b/arch/csky/kernel/dumpstack.c
index 659253e9989cb062e84f38c04ce9d4219ebf1d2e..d67f9777cfd9d7a10ca0b439937fd9784f88f8e6 100644
--- a/arch/csky/kernel/dumpstack.c
+++ b/arch/csky/kernel/dumpstack.c
@@ -38,7 +38,11 @@ void show_stack(struct task_struct *task, unsigned long *stack)
 		if (task)
 			stack = (unsigned long *)thread_saved_fp(task);
 		else
+#ifdef CONFIG_STACKTRACE
+			asm volatile("mov %0, r8\n":"=r"(stack)::"memory");
+#else
 			stack = (unsigned long *)&stack;
+#endif
 	}
 
 	show_trace(stack);
diff --git a/arch/csky/kernel/ptrace.c b/arch/csky/kernel/ptrace.c
index 57f1afe19a52cb7896021a47691fc17c37d0b4bb..f2f12fff36f70c90d260c8052e6ba5feb69b306c 100644
--- a/arch/csky/kernel/ptrace.c
+++ b/arch/csky/kernel/ptrace.c
@@ -8,6 +8,7 @@
 #include <linux/ptrace.h>
 #include <linux/regset.h>
 #include <linux/sched.h>
+#include <linux/sched/task_stack.h>
 #include <linux/signal.h>
 #include <linux/smp.h>
 #include <linux/uaccess.h>
@@ -159,7 +160,7 @@ static int fpr_set(struct task_struct *target,
 static const struct user_regset csky_regsets[] = {
 	[REGSET_GPR] = {
 		.core_note_type = NT_PRSTATUS,
-		.n = ELF_NGREG,
+		.n = sizeof(struct pt_regs) / sizeof(u32),
 		.size = sizeof(u32),
 		.align = sizeof(u32),
 		.get = &gpr_get,
diff --git a/arch/csky/kernel/smp.c b/arch/csky/kernel/smp.c
index ddc4dd79f2826f837b3557a239043f7b0aa1c162..b07a534b30627fa93d39edfed3090e57b29bb04e 100644
--- a/arch/csky/kernel/smp.c
+++ b/arch/csky/kernel/smp.c
@@ -160,7 +160,8 @@ int __cpu_up(unsigned int cpu, struct task_struct *tidle)
 {
 	unsigned long mask = 1 << cpu;
 
-	secondary_stack = (unsigned int)tidle->stack + THREAD_SIZE - 8;
+	secondary_stack =
+		(unsigned int) task_stack_page(tidle) + THREAD_SIZE - 8;
 	secondary_hint = mfcr("cr31");
 	secondary_ccr  = mfcr("cr18");
 
diff --git a/arch/csky/mm/ioremap.c b/arch/csky/mm/ioremap.c
index cb7c03e5cd218a4236d1cb686a2cc36f0e4f91ff..8473b6bdf51205b35b761dac33f6456d1216072f 100644
--- a/arch/csky/mm/ioremap.c
+++ b/arch/csky/mm/ioremap.c
@@ -46,3 +46,17 @@ void iounmap(void __iomem *addr)
 	vunmap((void *)((unsigned long)addr & PAGE_MASK));
 }
 EXPORT_SYMBOL(iounmap);
+
+pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
+			      unsigned long size, pgprot_t vma_prot)
+{
+	if (!pfn_valid(pfn)) {
+		vma_prot.pgprot |= _PAGE_SO;
+		return pgprot_noncached(vma_prot);
+	} else if (file->f_flags & O_SYNC) {
+		return pgprot_noncached(vma_prot);
+	}
+
+	return vma_prot;
+}
+EXPORT_SYMBOL(phys_mem_access_prot);