include/asm-m32r/uaccess.h - kernel/msm - Gitiles

 #ifndef _ASM_M32R_UACCESS_H
 #define _ASM_M32R_UACCESS_H

 /*
  *  linux/include/asm-m32r/uaccess.h
  *
  *  M32R version.
  *    Copyright (C) 2004  Hirokazu Takata <takata at linux-m32r.org>
  */

 #undef UACCESS_DEBUG

 #ifdef UACCESS_DEBUG
 #define UAPRINTK(args...) printk(args)
 #else
 #define UAPRINTK(args...)
 #endif /* UACCESS_DEBUG */

 /*
  * User space memory access functions
  */
 #include <linux/config.h>
 #include <linux/errno.h>
 #include <linux/thread_info.h>
 #include <asm/page.h>

 #define VERIFY_READ 0
 #define VERIFY_WRITE 1

 /*
  * The fs value determines whether argument validity checking should be
  * performed or not.  If get_fs() == USER_DS, checking is performed, with
  * get_fs() == KERNEL_DS, checking is bypassed.
  *
  * For historical reasons, these macros are grossly misnamed.
  */

 #define MAKE_MM_SEG(s)	((mm_segment_t) { (s) })

 #ifdef CONFIG_MMU
 #define KERNEL_DS	MAKE_MM_SEG(0xFFFFFFFF)
 #define USER_DS		MAKE_MM_SEG(PAGE_OFFSET)
 #else
 #define KERNEL_DS	MAKE_MM_SEG(0xFFFFFFFF)
 #define USER_DS		MAKE_MM_SEG(0xFFFFFFFF)
 #endif /* CONFIG_MMU */

 #define get_ds()	(KERNEL_DS)
 #ifdef CONFIG_MMU
 #define get_fs()	(current_thread_info()->addr_limit)
 #define set_fs(x)	(current_thread_info()->addr_limit = (x))
 #else
 static inline mm_segment_t get_fs(void)
 {
   return USER_DS;
 }

 static inline void set_fs(mm_segment_t s)
 {
 }
 #endif /* CONFIG_MMU */

 #define segment_eq(a,b)	((a).seg == (b).seg)

 #define __addr_ok(addr) \
 	((unsigned long)(addr) < (current_thread_info()->addr_limit.seg))

 /*
  * Test whether a block of memory is a valid user space address.
  * Returns 0 if the range is valid, nonzero otherwise.
  *
  * This is equivalent to the following test:
  * (u33)addr + (u33)size >= (u33)current->addr_limit.seg
  *
  * This needs 33-bit arithmetic. We have a carry...
  */
 #define __range_ok(addr,size) ({					\
 	unsigned long flag, sum; 					\
 	__chk_user_ptr(addr);						\
 	asm ( 								\
 		"	cmpu	%1, %1    ; clear cbit\n"		\
 		"	addx	%1, %3    ; set cbit if overflow\n"	\
 		"	subx	%0, %0\n"				\
 		"	cmpu	%4, %1\n"				\
 		"	subx	%0, %5\n"				\
 		: "=&r"(flag), "=r"(sum)				\
 		: "1"(addr), "r"((int)(size)), 				\
 		  "r"(current_thread_info()->addr_limit.seg), "r"(0)	\
 		: "cbit" );						\
 	flag; })

 /**
  * access_ok: - Checks if a user space pointer is valid
  * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
  *        %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
  *        to write to a block, it is always safe to read from it.
  * @addr: User space pointer to start of block to check
  * @size: Size of block to check
  *
  * Context: User context only.  This function may sleep.
  *
  * Checks if a pointer to a block of memory in user space is valid.
  *
  * Returns true (nonzero) if the memory block may be valid, false (zero)
  * if it is definitely invalid.
  *
  * Note that, depending on architecture, this function probably just
  * checks that the pointer is in the user space range - after calling
  * this function, memory access functions may still return -EFAULT.
  */
 #ifdef CONFIG_MMU
 #define access_ok(type,addr,size) (likely(__range_ok(addr,size) == 0))
 #else
 static inline int access_ok(int type, const void *addr, unsigned long size)
 {
   extern unsigned long memory_start, memory_end;
   unsigned long val = (unsigned long)addr;

   return ((val >= memory_start) && ((val + size) < memory_end));
 }
 #endif /* CONFIG_MMU */

 /*
  * The exception table consists of pairs of addresses: the first is the
  * address of an instruction that is allowed to fault, and the second is
  * the address at which the program should continue.  No registers are
  * modified, so it is entirely up to the continuation code to figure out
  * what to do.
  *
  * All the routines below use bits of fixup code that are out of line
  * with the main instruction path.  This means when everything is well,
  * we don't even have to jump over them.  Further, they do not intrude
  * on our cache or tlb entries.
  */

 struct exception_table_entry
 {
 	unsigned long insn, fixup;
 };

 extern int fixup_exception(struct pt_regs *regs);

 /*
  * 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 uglyness 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).
  */

 extern void __get_user_1(void);
 extern void __get_user_2(void);
 extern void __get_user_4(void);

 #ifndef MODULE
 #define __get_user_x(size,ret,x,ptr) 					\
 	__asm__ __volatile__(						\
 		"	mv	r0, %0\n"				\
 		"	mv	r1, %1\n" 				\
 		"	bl __get_user_" #size "\n"			\
 		"	mv	%0, r0\n"				\
 		"	mv	%1, r1\n" 				\
 		: "=r"(ret), "=r"(x) 					\
 		: "0"(ptr)						\
 		: "r0", "r1", "r14" )
 #else /* MODULE */
 /*
  * Use "jl" instead of "bl" for MODULE
  */
 #define __get_user_x(size,ret,x,ptr) 					\
 	__asm__ __volatile__(						\
 		"	mv	r0, %0\n"				\
 		"	mv	r1, %1\n" 				\
 		"	seth	lr, #high(__get_user_" #size ")\n"	\
 		"	or3	lr, lr, #low(__get_user_" #size ")\n"	\
 		"	jl 	lr\n"					\
 		"	mv	%0, r0\n"				\
 		"	mv	%1, r1\n" 				\
 		: "=r"(ret), "=r"(x) 					\
 		: "0"(ptr)						\
 		: "r0", "r1", "r14" )
 #endif

 /* Careful: we have to cast the result to the type of the pointer for sign
    reasons */
 /**
  * get_user: - Get a simple variable from user space.
  * @x:   Variable to store result.
  * @ptr: Source address, in user space.
  *
  * Context: User context only.  This function may sleep.
  *
  * This macro copies a single simple variable from user space to kernel
  * space.  It supports simple types like char and int, but not larger
  * data types like structures or arrays.
  *
  * @ptr must have pointer-to-simple-variable type, and the result of
  * dereferencing @ptr must be assignable to @x without a cast.
  *
  * Returns zero on success, or -EFAULT on error.
  * On error, the variable @x is set to zero.
  */
 #define get_user(x,ptr)							\
 ({	int __ret_gu;							\
 	unsigned long __val_gu;						\
 	__chk_user_ptr(ptr);						\
 	switch(sizeof (*(ptr))) {					\
 	case 1:  __get_user_x(1,__ret_gu,__val_gu,ptr); break;		\
 	case 2:  __get_user_x(2,__ret_gu,__val_gu,ptr); break;		\
 	case 4:  __get_user_x(4,__ret_gu,__val_gu,ptr); break;		\
 	default: __get_user_x(X,__ret_gu,__val_gu,ptr); break;		\
 	}								\
 	(x) = (__typeof__(*(ptr)))__val_gu;				\
 	__ret_gu;							\
 })

 extern void __put_user_bad(void);

 /**
  * put_user: - Write a simple value into user space.
  * @x:   Value to copy to user space.
  * @ptr: Destination address, in user space.
  *
  * Context: User context only.  This function may sleep.
  *
  * This macro copies a single simple value from kernel space to user
  * space.  It supports simple types like char and int, but not larger
  * data types like structures or arrays.
  *
  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
  * to the result of dereferencing @ptr.
  *
  * Returns zero on success, or -EFAULT on error.
  */
 #define put_user(x,ptr)							\
   __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))


 /**
  * __get_user: - Get a simple variable from user space, with less checking.
  * @x:   Variable to store result.
  * @ptr: Source address, in user space.
  *
  * Context: User context only.  This function may sleep.
  *
  * This macro copies a single simple variable from user space to kernel
  * space.  It supports simple types like char and int, but not larger
  * data types like structures or arrays.
  *
  * @ptr must have pointer-to-simple-variable type, and the result of
  * dereferencing @ptr must be assignable to @x without a cast.
  *
  * Caller must check the pointer with access_ok() before calling this
  * function.
  *
  * Returns zero on success, or -EFAULT on error.
  * On error, the variable @x is set to zero.
  */
 #define __get_user(x,ptr) \
   __get_user_nocheck((x),(ptr),sizeof(*(ptr)))


 /**
  * __put_user: - Write a simple value into user space, with less checking.
  * @x:   Value to copy to user space.
  * @ptr: Destination address, in user space.
  *
  * Context: User context only.  This function may sleep.
  *
  * This macro copies a single simple value from kernel space to user
  * space.  It supports simple types like char and int, but not larger
  * data types like structures or arrays.
  *
  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
  * to the result of dereferencing @ptr.
  *
  * Caller must check the pointer with access_ok() before calling this
  * function.
  *
  * Returns zero on success, or -EFAULT on error.
  */
 #define __put_user(x,ptr) \
   __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))

 #define __put_user_nocheck(x,ptr,size)					\
 ({									\
 	long __pu_err;							\
 	__put_user_size((x),(ptr),(size),__pu_err);			\
 	__pu_err;							\
 })


 #define __put_user_check(x,ptr,size)					\
 ({									\
 	long __pu_err = -EFAULT;					\
 	__typeof__(*(ptr)) __user *__pu_addr = (ptr);			\
 	might_sleep();							\
 	if (access_ok(VERIFY_WRITE,__pu_addr,size))			\
 		__put_user_size((x),__pu_addr,(size),__pu_err);		\
 	__pu_err;							\
 })

 #if defined(__LITTLE_ENDIAN__)
 #define __put_user_u64(x, addr, err)                                    \
         __asm__ __volatile__(                                           \
                 "       .fillinsn\n"                                    \
                 "1:     st %L1,@%2\n"                                    \
                 "       .fillinsn\n"                                    \
                 "2:     st %H1,@(4,%2)\n"                                \
                 "       .fillinsn\n"                                    \
                 "3:\n"                                                  \
                 ".section .fixup,\"ax\"\n"                              \
                 "       .balign 4\n"                                    \
                 "4:     ldi %0,%3\n"                                    \
                 "       seth r14,#high(3b)\n"                           \
                 "       or3 r14,r14,#low(3b)\n"                         \
                 "       jmp r14\n"                                      \
                 ".previous\n"                                           \
                 ".section __ex_table,\"a\"\n"                           \
                 "       .balign 4\n"                                    \
                 "       .long 1b,4b\n"                                  \
                 "       .long 2b,4b\n"                                  \
                 ".previous"                                             \
                 : "=&r"(err)                                             \
                 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err)		\
                 : "r14", "memory")

 #elif defined(__BIG_ENDIAN__)
 #define __put_user_u64(x, addr, err)					\
 	__asm__ __volatile__(						\
 		"	.fillinsn\n"					\
 		"1:	st %H1,@%2\n"					\
 		"	.fillinsn\n"					\
 		"2:	st %L1,@(4,%2)\n"				\
 		"	.fillinsn\n"					\
 		"3:\n"							\
 		".section .fixup,\"ax\"\n"				\
 		"	.balign 4\n"					\
 		"4:	ldi %0,%3\n"					\
 		"	seth r14,#high(3b)\n"				\
 		"	or3 r14,r14,#low(3b)\n"				\
 		"	jmp r14\n"					\
 		".previous\n"						\
 		".section __ex_table,\"a\"\n"				\
 		"	.balign 4\n"					\
 		"	.long 1b,4b\n"					\
 		"	.long 2b,4b\n"					\
 		".previous"						\
 		: "=&r"(err)						\
 		: "r"(x), "r"(addr), "i"(-EFAULT), "0"(err)		\
 		: "r14", "memory")
 #else
 #error no endian defined
 #endif

 #define __put_user_size(x,ptr,size,retval)				\
 do {									\
 	retval = 0;							\
 	__chk_user_ptr(ptr);						\
 	switch (size) {							\
 	  case 1: __put_user_asm(x,ptr,retval,"b"); break;		\
 	  case 2: __put_user_asm(x,ptr,retval,"h"); break;		\
 	  case 4: __put_user_asm(x,ptr,retval,""); break;		\
 	  case 8: __put_user_u64((__typeof__(*ptr))(x),ptr,retval); break;\
 	  default: __put_user_bad();					\
 	}								\
 } while (0)

 struct __large_struct { unsigned long buf[100]; };
 #define __m(x) (*(struct __large_struct *)(x))

 /*
  * 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.
  */
 #define __put_user_asm(x, addr, err, itype)				\
 	__asm__ __volatile__(						\
 		"	.fillinsn\n"					\
 		"1:	st"itype" %1,@%2\n"				\
 		"	.fillinsn\n"					\
 		"2:\n"							\
 		".section .fixup,\"ax\"\n"				\
 		"	.balign 4\n"					\
 		"3:	ldi %0,%3\n"					\
 		"	seth r14,#high(2b)\n"				\
 		"	or3 r14,r14,#low(2b)\n"				\
 		"	jmp r14\n"					\
 		".previous\n"						\
 		".section __ex_table,\"a\"\n"				\
 		"	.balign 4\n"					\
 		"	.long 1b,3b\n"					\
 		".previous"						\
 		: "=&r"(err)						\
 		: "r"(x), "r"(addr), "i"(-EFAULT), "0"(err)		\
 		: "r14", "memory")

 #define __get_user_nocheck(x,ptr,size)					\
 ({									\
 	long __gu_err;							\
 	unsigned long __gu_val;						\
 	__get_user_size(__gu_val,(ptr),(size),__gu_err);		\
 	(x) = (__typeof__(*(ptr)))__gu_val;				\
 	__gu_err;							\
 })

 extern long __get_user_bad(void);

 #define __get_user_size(x,ptr,size,retval)				\
 do {									\
 	retval = 0;							\
 	__chk_user_ptr(ptr);						\
 	switch (size) {							\
 	  case 1: __get_user_asm(x,ptr,retval,"ub"); break;		\
 	  case 2: __get_user_asm(x,ptr,retval,"uh"); break;		\
 	  case 4: __get_user_asm(x,ptr,retval,""); break;		\
 	  default: (x) = __get_user_bad();				\
 	}								\
 } while (0)

 #define __get_user_asm(x, addr, err, itype)				\
 	__asm__ __volatile__(						\
 		"	.fillinsn\n"					\
 		"1:	ld"itype" %1,@%2\n"				\
 		"	.fillinsn\n"					\
 		"2:\n"							\
 		".section .fixup,\"ax\"\n"				\
 		"	.balign 4\n"					\
 		"3:	ldi %0,%3\n"					\
 		"	seth r14,#high(2b)\n"				\
 		"	or3 r14,r14,#low(2b)\n"				\
 		"	jmp r14\n"					\
 		".previous\n"						\
 		".section __ex_table,\"a\"\n"				\
 		"	.balign 4\n"					\
 		"	.long 1b,3b\n"					\
 		".previous"						\
 		: "=&r"(err), "=&r"(x)					\
 		: "r"(addr), "i"(-EFAULT), "0"(err)			\
 		: "r14", "memory")

 /*
  * Here we special-case 1, 2 and 4-byte copy_*_user invocations.  On a fault
  * we return the initial request size (1, 2 or 4), as copy_*_user should do.
  * If a store crosses a page boundary and gets a fault, the m32r will not write
  * anything, so this is accurate.
  */


 /*
  * Copy To/From Userspace
  */

 /* Generic arbitrary sized copy.  */
 /* Return the number of bytes NOT copied.  */
 #define __copy_user(to,from,size)					\
 do {									\
 	unsigned long __dst, __src, __c;				\
 	__asm__ __volatile__ (						\
 		"	mv	r14, %0\n"				\
 		"	or	r14, %1\n"				\
 		"	beq	%0, %1, 9f\n"				\
 		"	beqz	%2, 9f\n"				\
 		"	and3	r14, r14, #3\n"				\
 		"	bnez	r14, 2f\n"				\
 		"	and3	%2, %2, #3\n"				\
 		"	beqz	%3, 2f\n"				\
 		"	addi	%0, #-4		; word_copy \n"		\
 		"	.fillinsn\n"					\
 		"0:	ld	r14, @%1+\n"				\
 		"	addi	%3, #-1\n"				\
 		"	.fillinsn\n"					\
 		"1:	st	r14, @+%0\n"				\
 		"	bnez	%3, 0b\n"				\
 		"	beqz	%2, 9f\n"				\
 		"	addi	%0, #4\n"				\
 		"	.fillinsn\n"					\
 		"2:	ldb	r14, @%1	; byte_copy \n"		\
 		"	.fillinsn\n"					\
 		"3:	stb	r14, @%0\n"				\
 		"	addi	%1, #1\n"				\
 		"	addi	%2, #-1\n"				\
 		"	addi	%0, #1\n"				\
 		"	bnez	%2, 2b\n"				\
 		"	.fillinsn\n"					\
 		"9:\n"							\
 		".section .fixup,\"ax\"\n"				\
 		"	.balign 4\n"					\
 		"5:	addi	%3, #1\n"				\
 		"	addi	%1, #-4\n"				\
 		"	.fillinsn\n"					\
 		"6:	slli	%3, #2\n"				\
 		"	add	%2, %3\n"				\
 		"	addi	%0, #4\n"				\
 		"	.fillinsn\n"					\
 		"7:	seth	r14, #high(9b)\n"			\
 		"	or3	r14, r14, #low(9b)\n"			\
 		"	jmp	r14\n"					\
 		".previous\n"						\
 		".section __ex_table,\"a\"\n"				\
 		"	.balign 4\n"					\
 		"	.long 0b,6b\n"					\
 		"	.long 1b,5b\n"					\
 		"	.long 2b,9b\n"					\
 		"	.long 3b,9b\n"					\
 		".previous\n"						\
 		: "=&r"(__dst), "=&r"(__src), "=&r"(size), "=&r"(__c)	\
 		: "0"(to), "1"(from), "2"(size), "3"(size / 4)		\
 		: "r14", "memory");					\
 } while (0)

 #define __copy_user_zeroing(to,from,size)				\
 do {									\
 	unsigned long __dst, __src, __c;				\
 	__asm__ __volatile__ (						\
 		"	mv	r14, %0\n"				\
 		"	or	r14, %1\n"				\
 		"	beq	%0, %1, 9f\n"				\
 		"	beqz	%2, 9f\n"				\
 		"	and3	r14, r14, #3\n"				\
 		"	bnez	r14, 2f\n"				\
 		"	and3	%2, %2, #3\n"				\
 		"	beqz	%3, 2f\n"				\
 		"	addi	%0, #-4		; word_copy \n"		\
 		"	.fillinsn\n"					\
 		"0:	ld	r14, @%1+\n"				\
 		"	addi	%3, #-1\n"				\
 		"	.fillinsn\n"					\
 		"1:	st	r14, @+%0\n"				\
 		"	bnez	%3, 0b\n"				\
 		"	beqz	%2, 9f\n"				\
 		"	addi	%0, #4\n"				\
 		"	.fillinsn\n"					\
 		"2:	ldb	r14, @%1	; byte_copy \n"		\
 		"	.fillinsn\n"					\
 		"3:	stb	r14, @%0\n"				\
 		"	addi	%1, #1\n"				\
 		"	addi	%2, #-1\n"				\
 		"	addi	%0, #1\n"				\
 		"	bnez	%2, 2b\n"				\
 		"	.fillinsn\n"					\
 		"9:\n"							\
 		".section .fixup,\"ax\"\n"				\
 		"	.balign 4\n"					\
 		"5:	addi	%3, #1\n"				\
 		"	addi	%1, #-4\n"				\
 		"	.fillinsn\n"					\
 		"6:	slli	%3, #2\n"				\
 		"	add	%2, %3\n"				\
 		"	addi	%0, #4\n"				\
 		"	.fillinsn\n"					\
 		"7:	ldi	r14, #0		; store zero \n"	\
 		"	.fillinsn\n"					\
 		"8:	addi	%2, #-1\n"				\
 		"	stb	r14, @%0	; ACE? \n"		\
 		"	addi	%0, #1\n"				\
 		"	bnez	%2, 8b\n"				\
 		"	seth	r14, #high(9b)\n"			\
 		"	or3	r14, r14, #low(9b)\n"			\
 		"	jmp	r14\n"					\
 		".previous\n"						\
 		".section __ex_table,\"a\"\n"				\
 		"	.balign 4\n"					\
 		"	.long 0b,6b\n"					\
 		"	.long 1b,5b\n"					\
 		"	.long 2b,7b\n"					\
 		"	.long 3b,7b\n"					\
 		".previous\n"						\
 		: "=&r"(__dst), "=&r"(__src), "=&r"(size), "=&r"(__c)	\
 		: "0"(to), "1"(from), "2"(size), "3"(size / 4)		\
 		: "r14", "memory");					\
 } while (0)


 /* We let the __ versions of copy_from/to_user inline, because they're often
  * used in fast paths and have only a small space overhead.
  */
 static inline unsigned long __generic_copy_from_user_nocheck(void *to,
 	const void __user *from, unsigned long n)
 {
 	__copy_user_zeroing(to,from,n);
 	return n;
 }

 static inline unsigned long __generic_copy_to_user_nocheck(void __user *to,
 	const void *from, unsigned long n)
 {
 	__copy_user(to,from,n);
 	return n;
 }

 unsigned long __generic_copy_to_user(void __user *, const void *, unsigned long);
 unsigned long __generic_copy_from_user(void *, const void __user *, unsigned long);

 /**
  * __copy_to_user: - Copy a block of data into user space, with less checking.
  * @to:   Destination address, in user space.
  * @from: Source address, in kernel space.
  * @n:    Number of bytes to copy.
  *
  * Context: User context only.  This function may sleep.
  *
  * Copy data from kernel space to user space.  Caller must check
  * the specified block with access_ok() before calling this function.
  *
  * Returns number of bytes that could not be copied.
  * On success, this will be zero.
  */
 #define __copy_to_user(to,from,n)			\
 	__generic_copy_to_user_nocheck((to),(from),(n))

 #define __copy_to_user_inatomic __copy_to_user
 #define __copy_from_user_inatomic __copy_from_user

 /**
  * copy_to_user: - Copy a block of data into user space.
  * @to:   Destination address, in user space.
  * @from: Source address, in kernel space.
  * @n:    Number of bytes to copy.
  *
  * Context: User context only.  This function may sleep.
  *
  * Copy data from kernel space to user space.
  *
  * Returns number of bytes that could not be copied.
  * On success, this will be zero.
  */
 #define copy_to_user(to,from,n)				\
 ({							\
 	might_sleep();					\
 	__generic_copy_to_user((to),(from),(n));	\
 })

 /**
  * __copy_from_user: - Copy a block of data from user space, with less checking. * @to:   Destination address, in kernel space.
  * @from: Source address, in user space.
  * @n:    Number of bytes to copy.
  *
  * Context: User context only.  This function may sleep.
  *
  * Copy data from user space to kernel space.  Caller must check
  * the specified block with access_ok() before calling this function.
  *
  * Returns number of bytes that could not be copied.
  * On success, this will be zero.
  *
  * If some data could not be copied, this function will pad the copied
  * data to the requested size using zero bytes.
  */
 #define __copy_from_user(to,from,n)			\
 	__generic_copy_from_user_nocheck((to),(from),(n))

 /**
  * copy_from_user: - Copy a block of data from user space.
  * @to:   Destination address, in kernel space.
  * @from: Source address, in user space.
  * @n:    Number of bytes to copy.
  *
  * Context: User context only.  This function may sleep.
  *
  * Copy data from user space to kernel space.
  *
  * Returns number of bytes that could not be copied.
  * On success, this will be zero.
  *
  * If some data could not be copied, this function will pad the copied
  * data to the requested size using zero bytes.
  */
 #define copy_from_user(to,from,n)			\
 ({							\
 	might_sleep();					\
 __generic_copy_from_user((to),(from),(n));	\
 })

 long __must_check strncpy_from_user(char *dst, const char __user *src,
 				long count);
 long __must_check __strncpy_from_user(char *dst,
 				const char __user *src, long count);

 /**
  * __clear_user: - Zero a block of memory in user space, with less checking.
  * @to:   Destination address, in user space.
  * @n:    Number of bytes to zero.
  *
  * Zero a block of memory in user space.  Caller must check
  * the specified block with access_ok() before calling this function.
  *
  * Returns number of bytes that could not be cleared.
  * On success, this will be zero.
  */
 unsigned long __clear_user(void __user *mem, unsigned long len);

 /**
  * clear_user: - Zero a block of memory in user space.
  * @to:   Destination address, in user space.
  * @n:    Number of bytes to zero.
  *
  * Zero a block of memory in user space.  Caller must check
  * the specified block with access_ok() before calling this function.
  *
  * Returns number of bytes that could not be cleared.
  * On success, this will be zero.
  */
 unsigned long clear_user(void __user *mem, unsigned long len);

 /**
  * strlen_user: - Get the size of a string in user space.
  * @str: The string to measure.
  *
  * Context: User context only.  This function may sleep.
  *
  * Get the size of a NUL-terminated string in user space.
  *
  * Returns the size of the string INCLUDING the terminating NUL.
  * On exception, returns 0.
  *
  * If there is a limit on the length of a valid string, you may wish to
  * consider using strnlen_user() instead.
  */
 #define strlen_user(str) strnlen_user(str, ~0UL >> 1)
 long strnlen_user(const char __user *str, long n);

 #endif /* _ASM_M32R_UACCESS_H */
	#ifndef _ASM_M32R_UACCESS_H
	#define _ASM_M32R_UACCESS_H

	/*
	* linux/include/asm-m32r/uaccess.h
	*
	* M32R version.
	* Copyright (C) 2004 Hirokazu Takata <takata at linux-m32r.org>
	*/

	#undef UACCESS_DEBUG

	#ifdef UACCESS_DEBUG
	#define UAPRINTK(args...) printk(args)
	#else
	#define UAPRINTK(args...)
	#endif /* UACCESS_DEBUG */

	/*
	* User space memory access functions
	*/
	#include <linux/config.h>
	#include <linux/errno.h>
	#include <linux/thread_info.h>
	#include <asm/page.h>

	#define VERIFY_READ 0
	#define VERIFY_WRITE 1

	/*
	* The fs value determines whether argument validity checking should be
	* performed or not. If get_fs() == USER_DS, checking is performed, with
	* get_fs() == KERNEL_DS, checking is bypassed.
	*
	* For historical reasons, these macros are grossly misnamed.
	*/

	#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })

	#ifdef CONFIG_MMU
	#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
	#define USER_DS MAKE_MM_SEG(PAGE_OFFSET)
	#else
	#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
	#define USER_DS MAKE_MM_SEG(0xFFFFFFFF)
	#endif /* CONFIG_MMU */

	#define get_ds() (KERNEL_DS)
	#ifdef CONFIG_MMU
	#define get_fs() (current_thread_info()->addr_limit)
	#define set_fs(x) (current_thread_info()->addr_limit = (x))
	#else
	static inline mm_segment_t get_fs(void)
	{
	return USER_DS;
	}

	static inline void set_fs(mm_segment_t s)
	{
	}
	#endif /* CONFIG_MMU */

	#define segment_eq(a,b) ((a).seg == (b).seg)

	#define __addr_ok(addr) \
	((unsigned long)(addr) < (current_thread_info()->addr_limit.seg))

	/*
	* Test whether a block of memory is a valid user space address.
	* Returns 0 if the range is valid, nonzero otherwise.
	*
	* This is equivalent to the following test:
	* (u33)addr + (u33)size >= (u33)current->addr_limit.seg
	*
	* This needs 33-bit arithmetic. We have a carry...
	*/
	#define __range_ok(addr,size) ({ \
	unsigned long flag, sum; \
	__chk_user_ptr(addr); \
	asm ( \
	" cmpu %1, %1 ; clear cbit\n" \
	" addx %1, %3 ; set cbit if overflow\n" \
	" subx %0, %0\n" \
	" cmpu %4, %1\n" \
	" subx %0, %5\n" \
	: "=&r"(flag), "=r"(sum) \
	: "1"(addr), "r"((int)(size)), \
	"r"(current_thread_info()->addr_limit.seg), "r"(0) \
	: "cbit" ); \
	flag; })

	/**
	* access_ok: - Checks if a user space pointer is valid
	* @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that
	* %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
	* to write to a block, it is always safe to read from it.
	* @addr: User space pointer to start of block to check
	* @size: Size of block to check
	*
	* Context: User context only. This function may sleep.
	*
	* Checks if a pointer to a block of memory in user space is valid.
	*
	* Returns true (nonzero) if the memory block may be valid, false (zero)
	* if it is definitely invalid.
	*
	* Note that, depending on architecture, this function probably just
	* checks that the pointer is in the user space range - after calling
	* this function, memory access functions may still return -EFAULT.
	*/
	#ifdef CONFIG_MMU
	#define access_ok(type,addr,size) (likely(__range_ok(addr,size) == 0))
	#else
	static inline int access_ok(int type, const void *addr, unsigned long size)
	{
	extern unsigned long memory_start, memory_end;
	unsigned long val = (unsigned long)addr;

	return ((val >= memory_start) && ((val + size) < memory_end));
	}
	#endif /* CONFIG_MMU */

	/*
	* The exception table consists of pairs of addresses: the first is the
	* address of an instruction that is allowed to fault, and the second is
	* the address at which the program should continue. No registers are
	* modified, so it is entirely up to the continuation code to figure out
	* what to do.
	*
	* All the routines below use bits of fixup code that are out of line
	* with the main instruction path. This means when everything is well,
	* we don't even have to jump over them. Further, they do not intrude
	* on our cache or tlb entries.
	*/

	struct exception_table_entry
	{
	unsigned long insn, fixup;
	};

	extern int fixup_exception(struct pt_regs *regs);

	/*
	* 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 uglyness 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).
	*/

	extern void __get_user_1(void);
	extern void __get_user_2(void);
	extern void __get_user_4(void);

	#ifndef MODULE
	#define __get_user_x(size,ret,x,ptr) \
	__asm__ __volatile__( \
	" mv r0, %0\n" \
	" mv r1, %1\n" \
	" bl __get_user_" #size "\n" \
	" mv %0, r0\n" \
	" mv %1, r1\n" \
	: "=r"(ret), "=r"(x) \
	: "0"(ptr) \
	: "r0", "r1", "r14" )
	#else /* MODULE */
	/*
	* Use "jl" instead of "bl" for MODULE
	*/
	#define __get_user_x(size,ret,x,ptr) \
	__asm__ __volatile__( \
	" mv r0, %0\n" \
	" mv r1, %1\n" \
	" seth lr, #high(__get_user_" #size ")\n" \
	" or3 lr, lr, #low(__get_user_" #size ")\n" \
	" jl lr\n" \
	" mv %0, r0\n" \
	" mv %1, r1\n" \
	: "=r"(ret), "=r"(x) \
	: "0"(ptr) \
	: "r0", "r1", "r14" )
	#endif

	/* Careful: we have to cast the result to the type of the pointer for sign
	reasons */
	/**
	* get_user: - Get a simple variable from user space.
	* @x: Variable to store result.
	* @ptr: Source address, in user space.
	*
	* Context: User context only. This function may sleep.
	*
	* This macro copies a single simple variable from user space to kernel
	* space. It supports simple types like char and int, but not larger
	* data types like structures or arrays.
	*
	* @ptr must have pointer-to-simple-variable type, and the result of
	* dereferencing @ptr must be assignable to @x without a cast.
	*
	* Returns zero on success, or -EFAULT on error.
	* On error, the variable @x is set to zero.
	*/
	#define get_user(x,ptr) \
	({ int __ret_gu; \
	unsigned long __val_gu; \
	__chk_user_ptr(ptr); \
	switch(sizeof (*(ptr))) { \
	case 1: __get_user_x(1,__ret_gu,__val_gu,ptr); break; \
	case 2: __get_user_x(2,__ret_gu,__val_gu,ptr); break; \
	case 4: __get_user_x(4,__ret_gu,__val_gu,ptr); break; \
	default: __get_user_x(X,__ret_gu,__val_gu,ptr); break; \
	} \
	(x) = (__typeof__(*(ptr)))__val_gu; \
	__ret_gu; \
	})

	extern void __put_user_bad(void);

	/**
	* put_user: - Write a simple value into user space.
	* @x: Value to copy to user space.
	* @ptr: Destination address, in user space.
	*
	* Context: User context only. This function may sleep.
	*
	* This macro copies a single simple value from kernel space to user
	* space. It supports simple types like char and int, but not larger
	* data types like structures or arrays.
	*
	* @ptr must have pointer-to-simple-variable type, and @x must be assignable
	* to the result of dereferencing @ptr.
	*
	* Returns zero on success, or -EFAULT on error.
	*/
	#define put_user(x,ptr) \
	__put_user_check((__typeof__((ptr)))(x),(ptr),sizeof((ptr)))


	/**
	* __get_user: - Get a simple variable from user space, with less checking.
	* @x: Variable to store result.
	* @ptr: Source address, in user space.
	*
	* Context: User context only. This function may sleep.
	*
	* This macro copies a single simple variable from user space to kernel
	* space. It supports simple types like char and int, but not larger
	* data types like structures or arrays.
	*
	* @ptr must have pointer-to-simple-variable type, and the result of
	* dereferencing @ptr must be assignable to @x without a cast.
	*
	* Caller must check the pointer with access_ok() before calling this
	* function.
	*
	* Returns zero on success, or -EFAULT on error.
	* On error, the variable @x is set to zero.
	*/
	#define __get_user(x,ptr) \
	__get_user_nocheck((x),(ptr),sizeof(*(ptr)))


	/**
	* __put_user: - Write a simple value into user space, with less checking.
	* @x: Value to copy to user space.
	* @ptr: Destination address, in user space.
	*
	* Context: User context only. This function may sleep.
	*
	* This macro copies a single simple value from kernel space to user
	* space. It supports simple types like char and int, but not larger
	* data types like structures or arrays.
	*
	* @ptr must have pointer-to-simple-variable type, and @x must be assignable
	* to the result of dereferencing @ptr.
	*
	* Caller must check the pointer with access_ok() before calling this
	* function.
	*
	* Returns zero on success, or -EFAULT on error.
	*/
	#define __put_user(x,ptr) \
	__put_user_nocheck((__typeof__((ptr)))(x),(ptr),sizeof((ptr)))

	#define __put_user_nocheck(x,ptr,size) \
	({ \
	long __pu_err; \
	__put_user_size((x),(ptr),(size),__pu_err); \
	__pu_err; \
	})


	#define __put_user_check(x,ptr,size) \
	({ \
	long __pu_err = -EFAULT; \
	__typeof__((ptr)) __user __pu_addr = (ptr); \
	might_sleep(); \
	if (access_ok(VERIFY_WRITE,__pu_addr,size)) \
	__put_user_size((x),__pu_addr,(size),__pu_err); \
	__pu_err; \
	})

	#if defined(__LITTLE_ENDIAN__)
	#define __put_user_u64(x, addr, err) \
	__asm__ __volatile__( \
	" .fillinsn\n" \
	"1: st %L1,@%2\n" \
	" .fillinsn\n" \
	"2: st %H1,@(4,%2)\n" \
	" .fillinsn\n" \
	"3:\n" \
	".section .fixup,\"ax\"\n" \
	" .balign 4\n" \
	"4: ldi %0,%3\n" \
	" seth r14,#high(3b)\n" \
	" or3 r14,r14,#low(3b)\n" \
	" jmp r14\n" \
	".previous\n" \
	".section __ex_table,\"a\"\n" \
	" .balign 4\n" \
	" .long 1b,4b\n" \
	" .long 2b,4b\n" \
	".previous" \
	: "=&r"(err) \
	: "r"(x), "r"(addr), "i"(-EFAULT), "0"(err) \
	: "r14", "memory")

	#elif defined(__BIG_ENDIAN__)
	#define __put_user_u64(x, addr, err) \
	__asm__ __volatile__( \
	" .fillinsn\n" \
	"1: st %H1,@%2\n" \
	" .fillinsn\n" \
	"2: st %L1,@(4,%2)\n" \
	" .fillinsn\n" \
	"3:\n" \
	".section .fixup,\"ax\"\n" \
	" .balign 4\n" \
	"4: ldi %0,%3\n" \
	" seth r14,#high(3b)\n" \
	" or3 r14,r14,#low(3b)\n" \
	" jmp r14\n" \
	".previous\n" \
	".section __ex_table,\"a\"\n" \
	" .balign 4\n" \
	" .long 1b,4b\n" \
	" .long 2b,4b\n" \
	".previous" \
	: "=&r"(err) \
	: "r"(x), "r"(addr), "i"(-EFAULT), "0"(err) \
	: "r14", "memory")
	#else
	#error no endian defined
	#endif

	#define __put_user_size(x,ptr,size,retval) \
	do { \
	retval = 0; \
	__chk_user_ptr(ptr); \
	switch (size) { \
	case 1: __put_user_asm(x,ptr,retval,"b"); break; \
	case 2: __put_user_asm(x,ptr,retval,"h"); break; \
	case 4: __put_user_asm(x,ptr,retval,""); break; \
	case 8: __put_user_u64((__typeof__(*ptr))(x),ptr,retval); break;\
	default: __put_user_bad(); \
	} \
	} while (0)

	struct __large_struct { unsigned long buf[100]; };
	#define __m(x) ((struct __large_struct )(x))

	/*
	* 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.
	*/
	#define __put_user_asm(x, addr, err, itype) \
	__asm__ __volatile__( \
	" .fillinsn\n" \
	"1: st"itype" %1,@%2\n" \
	" .fillinsn\n" \
	"2:\n" \
	".section .fixup,\"ax\"\n" \
	" .balign 4\n" \
	"3: ldi %0,%3\n" \
	" seth r14,#high(2b)\n" \
	" or3 r14,r14,#low(2b)\n" \
	" jmp r14\n" \
	".previous\n" \
	".section __ex_table,\"a\"\n" \
	" .balign 4\n" \
	" .long 1b,3b\n" \
	".previous" \
	: "=&r"(err) \
	: "r"(x), "r"(addr), "i"(-EFAULT), "0"(err) \
	: "r14", "memory")

	#define __get_user_nocheck(x,ptr,size) \
	({ \
	long __gu_err; \
	unsigned long __gu_val; \
	__get_user_size(__gu_val,(ptr),(size),__gu_err); \
	(x) = (__typeof__(*(ptr)))__gu_val; \
	__gu_err; \
	})

	extern long __get_user_bad(void);

	#define __get_user_size(x,ptr,size,retval) \
	do { \
	retval = 0; \
	__chk_user_ptr(ptr); \
	switch (size) { \
	case 1: __get_user_asm(x,ptr,retval,"ub"); break; \
	case 2: __get_user_asm(x,ptr,retval,"uh"); break; \
	case 4: __get_user_asm(x,ptr,retval,""); break; \
	default: (x) = __get_user_bad(); \
	} \
	} while (0)

	#define __get_user_asm(x, addr, err, itype) \
	__asm__ __volatile__( \
	" .fillinsn\n" \
	"1: ld"itype" %1,@%2\n" \
	" .fillinsn\n" \
	"2:\n" \
	".section .fixup,\"ax\"\n" \
	" .balign 4\n" \
	"3: ldi %0,%3\n" \
	" seth r14,#high(2b)\n" \
	" or3 r14,r14,#low(2b)\n" \
	" jmp r14\n" \
	".previous\n" \
	".section __ex_table,\"a\"\n" \
	" .balign 4\n" \
	" .long 1b,3b\n" \
	".previous" \
	: "=&r"(err), "=&r"(x) \
	: "r"(addr), "i"(-EFAULT), "0"(err) \
	: "r14", "memory")

	/*
	* Here we special-case 1, 2 and 4-byte copy_*_user invocations. On a fault
	* we return the initial request size (1, 2 or 4), as copy_*_user should do.
	* If a store crosses a page boundary and gets a fault, the m32r will not write
	* anything, so this is accurate.
	*/


	/*
	* Copy To/From Userspace
	*/

	/* Generic arbitrary sized copy. */
	/* Return the number of bytes NOT copied. */
	#define __copy_user(to,from,size) \
	do { \
	unsigned long __dst, __src, __c; \
	__asm__ __volatile__ ( \
	" mv r14, %0\n" \
	" or r14, %1\n" \
	" beq %0, %1, 9f\n" \
	" beqz %2, 9f\n" \
	" and3 r14, r14, #3\n" \
	" bnez r14, 2f\n" \
	" and3 %2, %2, #3\n" \
	" beqz %3, 2f\n" \
	" addi %0, #-4 ; word_copy \n" \
	" .fillinsn\n" \
	"0: ld r14, @%1+\n" \
	" addi %3, #-1\n" \
	" .fillinsn\n" \
	"1: st r14, @+%0\n" \
	" bnez %3, 0b\n" \
	" beqz %2, 9f\n" \
	" addi %0, #4\n" \
	" .fillinsn\n" \
	"2: ldb r14, @%1 ; byte_copy \n" \
	" .fillinsn\n" \
	"3: stb r14, @%0\n" \
	" addi %1, #1\n" \
	" addi %2, #-1\n" \
	" addi %0, #1\n" \
	" bnez %2, 2b\n" \
	" .fillinsn\n" \
	"9:\n" \
	".section .fixup,\"ax\"\n" \
	" .balign 4\n" \
	"5: addi %3, #1\n" \
	" addi %1, #-4\n" \
	" .fillinsn\n" \
	"6: slli %3, #2\n" \
	" add %2, %3\n" \
	" addi %0, #4\n" \
	" .fillinsn\n" \
	"7: seth r14, #high(9b)\n" \
	" or3 r14, r14, #low(9b)\n" \
	" jmp r14\n" \
	".previous\n" \
	".section __ex_table,\"a\"\n" \
	" .balign 4\n" \
	" .long 0b,6b\n" \
	" .long 1b,5b\n" \
	" .long 2b,9b\n" \
	" .long 3b,9b\n" \
	".previous\n" \
	: "=&r"(__dst), "=&r"(__src), "=&r"(size), "=&r"(__c) \
	: "0"(to), "1"(from), "2"(size), "3"(size / 4) \
	: "r14", "memory"); \
	} while (0)

	#define __copy_user_zeroing(to,from,size) \
	do { \
	unsigned long __dst, __src, __c; \
	__asm__ __volatile__ ( \
	" mv r14, %0\n" \
	" or r14, %1\n" \
	" beq %0, %1, 9f\n" \
	" beqz %2, 9f\n" \
	" and3 r14, r14, #3\n" \
	" bnez r14, 2f\n" \
	" and3 %2, %2, #3\n" \
	" beqz %3, 2f\n" \
	" addi %0, #-4 ; word_copy \n" \
	" .fillinsn\n" \
	"0: ld r14, @%1+\n" \
	" addi %3, #-1\n" \
	" .fillinsn\n" \
	"1: st r14, @+%0\n" \
	" bnez %3, 0b\n" \
	" beqz %2, 9f\n" \
	" addi %0, #4\n" \
	" .fillinsn\n" \
	"2: ldb r14, @%1 ; byte_copy \n" \
	" .fillinsn\n" \
	"3: stb r14, @%0\n" \
	" addi %1, #1\n" \
	" addi %2, #-1\n" \
	" addi %0, #1\n" \
	" bnez %2, 2b\n" \
	" .fillinsn\n" \
	"9:\n" \
	".section .fixup,\"ax\"\n" \
	" .balign 4\n" \
	"5: addi %3, #1\n" \
	" addi %1, #-4\n" \
	" .fillinsn\n" \
	"6: slli %3, #2\n" \
	" add %2, %3\n" \
	" addi %0, #4\n" \
	" .fillinsn\n" \
	"7: ldi r14, #0 ; store zero \n" \
	" .fillinsn\n" \
	"8: addi %2, #-1\n" \
	" stb r14, @%0 ; ACE? \n" \
	" addi %0, #1\n" \
	" bnez %2, 8b\n" \
	" seth r14, #high(9b)\n" \
	" or3 r14, r14, #low(9b)\n" \
	" jmp r14\n" \
	".previous\n" \
	".section __ex_table,\"a\"\n" \
	" .balign 4\n" \
	" .long 0b,6b\n" \
	" .long 1b,5b\n" \
	" .long 2b,7b\n" \
	" .long 3b,7b\n" \
	".previous\n" \
	: "=&r"(__dst), "=&r"(__src), "=&r"(size), "=&r"(__c) \
	: "0"(to), "1"(from), "2"(size), "3"(size / 4) \
	: "r14", "memory"); \
	} while (0)


	/* We let the __ versions of copy_from/to_user inline, because they're often
	* used in fast paths and have only a small space overhead.
	*/
	static inline unsigned long __generic_copy_from_user_nocheck(void *to,
	const void __user *from, unsigned long n)
	{
	__copy_user_zeroing(to,from,n);
	return n;
	}

	static inline unsigned long __generic_copy_to_user_nocheck(void __user *to,
	const void *from, unsigned long n)
	{
	__copy_user(to,from,n);
	return n;
	}

	unsigned long __generic_copy_to_user(void __user , const void , unsigned long);
	unsigned long __generic_copy_from_user(void , const void __user , unsigned long);

	/**
	* __copy_to_user: - Copy a block of data into user space, with less checking.
	* @to: Destination address, in user space.
	* @from: Source address, in kernel space.
	* @n: Number of bytes to copy.
	*
	* Context: User context only. This function may sleep.
	*
	* Copy data from kernel space to user space. Caller must check
	* the specified block with access_ok() before calling this function.
	*
	* Returns number of bytes that could not be copied.
	* On success, this will be zero.
	*/
	#define __copy_to_user(to,from,n) \
	__generic_copy_to_user_nocheck((to),(from),(n))

	#define __copy_to_user_inatomic __copy_to_user
	#define __copy_from_user_inatomic __copy_from_user

	/**
	* copy_to_user: - Copy a block of data into user space.
	* @to: Destination address, in user space.
	* @from: Source address, in kernel space.
	* @n: Number of bytes to copy.
	*
	* Context: User context only. This function may sleep.
	*
	* Copy data from kernel space to user space.
	*
	* Returns number of bytes that could not be copied.
	* On success, this will be zero.
	*/
	#define copy_to_user(to,from,n) \
	({ \
	might_sleep(); \
	__generic_copy_to_user((to),(from),(n)); \
	})

	/**
	* __copy_from_user: - Copy a block of data from user space, with less checking. * @to: Destination address, in kernel space.
	* @from: Source address, in user space.
	* @n: Number of bytes to copy.
	*
	* Context: User context only. This function may sleep.
	*
	* Copy data from user space to kernel space. Caller must check
	* the specified block with access_ok() before calling this function.
	*
	* Returns number of bytes that could not be copied.
	* On success, this will be zero.
	*
	* If some data could not be copied, this function will pad the copied
	* data to the requested size using zero bytes.
	*/
	#define __copy_from_user(to,from,n) \
	__generic_copy_from_user_nocheck((to),(from),(n))

	/**
	* copy_from_user: - Copy a block of data from user space.
	* @to: Destination address, in kernel space.
	* @from: Source address, in user space.
	* @n: Number of bytes to copy.
	*
	* Context: User context only. This function may sleep.
	*
	* Copy data from user space to kernel space.
	*
	* Returns number of bytes that could not be copied.
	* On success, this will be zero.
	*
	* If some data could not be copied, this function will pad the copied
	* data to the requested size using zero bytes.
	*/
	#define copy_from_user(to,from,n) \
	({ \
	might_sleep(); \
	__generic_copy_from_user((to),(from),(n)); \
	})

	long __must_check strncpy_from_user(char dst, const char __user src,
	long count);
	long __must_check __strncpy_from_user(char *dst,
	const char __user *src, long count);

	/**
	* __clear_user: - Zero a block of memory in user space, with less checking.
	* @to: Destination address, in user space.
	* @n: Number of bytes to zero.
	*
	* Zero a block of memory in user space. Caller must check
	* the specified block with access_ok() before calling this function.
	*
	* Returns number of bytes that could not be cleared.
	* On success, this will be zero.
	*/
	unsigned long __clear_user(void __user *mem, unsigned long len);

	/**
	* clear_user: - Zero a block of memory in user space.
	* @to: Destination address, in user space.
	* @n: Number of bytes to zero.
	*
	* Zero a block of memory in user space. Caller must check
	* the specified block with access_ok() before calling this function.
	*
	* Returns number of bytes that could not be cleared.
	* On success, this will be zero.
	*/
	unsigned long clear_user(void __user *mem, unsigned long len);

	/**
	* strlen_user: - Get the size of a string in user space.
	* @str: The string to measure.
	*
	* Context: User context only. This function may sleep.
	*
	* Get the size of a NUL-terminated string in user space.
	*
	* Returns the size of the string INCLUDING the terminating NUL.
	* On exception, returns 0.
	*
	* If there is a limit on the length of a valid string, you may wish to
	* consider using strnlen_user() instead.
	*/
	#define strlen_user(str) strnlen_user(str, ~0UL >> 1)
	long strnlen_user(const char __user *str, long n);

	#endif /* _ASM_M32R_UACCESS_H */