[linux-2.6-block.git] / arch / microblaze / include / asm / uaccess.h

/*
 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
 * Copyright (C) 2008-2009 PetaLogix
 * Copyright (C) 2006 Atmark Techno, Inc.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License. See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#ifndef _ASM_MICROBLAZE_UACCESS_H
#define _ASM_MICROBLAZE_UACCESS_H

#ifdef __KERNEL__
#ifndef __ASSEMBLY__

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/sched.h> /* RLIMIT_FSIZE */
#include <linux/mm.h>

#include <asm/mmu.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <linux/string.h>

#define VERIFY_READ	0
#define VERIFY_WRITE	1

/*
 * On Microblaze the fs value is actually the top of the corresponding
 * address space.
 *
 * 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.
 *
 * For non-MMU arch like Microblaze, KERNEL_DS and USER_DS is equal.
 */
# define MAKE_MM_SEG(s)       ((mm_segment_t) { (s) })

#  ifndef CONFIG_MMU
#  define KERNEL_DS	MAKE_MM_SEG(0)
#  define USER_DS	KERNEL_DS
#  else
#  define KERNEL_DS	MAKE_MM_SEG(0xFFFFFFFF)
#  define USER_DS	MAKE_MM_SEG(TASK_SIZE - 1)
#  endif

# define get_ds()	(KERNEL_DS)
# define get_fs()	(current_thread_info()->addr_limit)
# define set_fs(val)	(current_thread_info()->addr_limit = (val))

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


#define __clear_user(addr, n)	(memset((void *)(addr), 0, (n)), 0)

#ifndef CONFIG_MMU

extern int ___range_ok(unsigned long addr, unsigned long size);

#define __range_ok(addr, size) \
		___range_ok((unsigned long)(addr), (unsigned long)(size))

#define access_ok(type, addr, size) (__range_ok((addr), (size)) == 0)
#define __access_ok(add, size) (__range_ok((addr), (size)) == 0)

/* Undefined function to trigger linker error */
extern int bad_user_access_length(void);

/* FIXME this is function for optimalization -> memcpy */
#define __get_user(var, ptr)				\
({							\
	int __gu_err = 0;				\
	switch (sizeof(*(ptr))) {			\
	case 1:						\
	case 2:						\
	case 4:						\
		(var) = *(ptr);				\
		break;					\
	case 8:						\
		memcpy((void *) &(var), (ptr), 8);	\
		break;					\
	default:					\
		(var) = 0;				\
		__gu_err = __get_user_bad();		\
		break;					\
	}						\
	__gu_err;					\
})

#define __get_user_bad()	(bad_user_access_length(), (-EFAULT))

/* FIXME is not there defined __pu_val */
#define __put_user(var, ptr)					\
({								\
	int __pu_err = 0;					\
	switch (sizeof(*(ptr))) {				\
	case 1:							\
	case 2:							\
	case 4:							\
		*(ptr) = (var);					\
		break;						\
	case 8: {						\
		typeof(*(ptr)) __pu_val = (var);		\
		memcpy(ptr, &__pu_val, sizeof(__pu_val));	\
		}						\
		break;						\
	default:						\
		__pu_err = __put_user_bad();			\
		break;						\
	}							\
	__pu_err;						\
})

#define __put_user_bad()	(bad_user_access_length(), (-EFAULT))

#define put_user(x, ptr)	__put_user((x), (ptr))
#define get_user(x, ptr)	__get_user((x), (ptr))

#define copy_to_user(to, from, n)	(memcpy((to), (from), (n)), 0)
#define copy_from_user(to, from, n)	(memcpy((to), (from), (n)), 0)

#define __copy_to_user(to, from, n)	(copy_to_user((to), (from), (n)))
#define __copy_from_user(to, from, n)	(copy_from_user((to), (from), (n)))
#define __copy_to_user_inatomic(to, from, n) \
			(__copy_to_user((to), (from), (n)))
#define __copy_from_user_inatomic(to, from, n) \
			(__copy_from_user((to), (from), (n)))

static inline unsigned long clear_user(void *addr, unsigned long size)
{
	if (access_ok(VERIFY_WRITE, addr, size))
		size = __clear_user(addr, size);
	return size;
}

/* Returns 0 if exception not found and fixup otherwise.  */
extern unsigned long search_exception_table(unsigned long);

extern long strncpy_from_user(char *dst, const char *src, long count);
extern long strnlen_user(const char *src, long count);

#else /* CONFIG_MMU */

/*
 * Address is valid if:
 *  - "addr", "addr + size" and "size" are all below the limit
 */
#define access_ok(type, addr, size) \
	(get_fs().seg > (((unsigned long)(addr)) | \
		(size) | ((unsigned long)(addr) + (size))))

/* || printk("access_ok failed for %s at 0x%08lx (size %d), seg 0x%08x\n",
 type?"WRITE":"READ",addr,size,get_fs().seg)) */

/*
 * All the __XXX versions macros/functions below do not perform
 * access checking. It is assumed that the necessary checks have been
 * already performed before the finction (macro) is called.
 */

#define get_user(x, ptr)						\
({									\
	access_ok(VERIFY_READ, (ptr), sizeof(*(ptr)))			\
		? __get_user((x), (ptr)) : -EFAULT;			\
})

#define put_user(x, ptr)						\
({									\
	access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr)))			\
		? __put_user((x), (ptr)) : -EFAULT;			\
})

#define __get_user(x, ptr)						\
({									\
	unsigned long __gu_val;						\
	/*unsigned long __gu_ptr = (unsigned long)(ptr);*/		\
	long __gu_err;							\
	switch (sizeof(*(ptr))) {					\
	case 1:								\
		__get_user_asm("lbu", (ptr), __gu_val, __gu_err);	\
		break;							\
	case 2:								\
		__get_user_asm("lhu", (ptr), __gu_val, __gu_err);	\
		break;							\
	case 4:								\
		__get_user_asm("lw", (ptr), __gu_val, __gu_err);	\
		break;							\
	default:							\
		__gu_val = 0; __gu_err = -EINVAL;			\
	}								\
	x = (__typeof__(*(ptr))) __gu_val;				\
	__gu_err;							\
})

#define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err)		\
({									\
	__asm__ __volatile__ (						\
			"1:"	insn	" %1, %2, r0;			\
				addk	%0, r0, r0;			\
			2:						\
			.section .fixup,\"ax\";				\
			3:	brid	2b;				\
				addik	%0, r0, %3;			\
			.previous;					\
			.section __ex_table,\"a\";			\
			.word	1b,3b;					\
			.previous;"					\
		: "=r"(__gu_err), "=r"(__gu_val)			\
		: "r"(__gu_ptr), "i"(-EFAULT)				\
	);								\
})

#define __put_user(x, ptr)						\
({									\
	__typeof__(*(ptr)) volatile __gu_val = (x);			\
	long __gu_err = 0;						\
	switch (sizeof(__gu_val)) {					\
	case 1:								\
		__put_user_asm("sb", (ptr), __gu_val, __gu_err);	\
		break;							\
	case 2: 							\
		__put_user_asm("sh", (ptr), __gu_val, __gu_err);	\
		break;							\
	case 4:								\
		__put_user_asm("sw", (ptr), __gu_val, __gu_err);	\
		break;							\
	case 8:								\
		__put_user_asm_8((ptr), __gu_val, __gu_err);		\
		break;							\
	default:							\
		__gu_err = -EINVAL;					\
	}								\
	__gu_err;							\
})

#define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err)	\
({							\
__asm__ __volatile__ ("	lwi	%0, %1, 0;		\
		1:	swi	%0, %2, 0;		\
			lwi	%0, %1, 4;		\
		2:	swi	%0, %2, 4;		\
			addk	%0,r0,r0;		\
		3:					\
		.section .fixup,\"ax\";			\
		4:	brid	3b;			\
			addik	%0, r0, %3;		\
		.previous;				\
		.section __ex_table,\"a\";		\
		.word	1b,4b,2b,4b;			\
		.previous;"				\
	: "=&r"(__gu_err)				\
	: "r"(&__gu_val),				\
	"r"(__gu_ptr), "i"(-EFAULT)			\
	);						\
})

#define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err)	\
({								\
	__asm__ __volatile__ (					\
			"1:"	insn	" %1, %2, r0;		\
				addk	%0, r0, r0;		\
			2:					\
			.section .fixup,\"ax\";			\
			3:	brid	2b;			\
				addik	%0, r0, %3;		\
			.previous;				\
			.section __ex_table,\"a\";		\
			.word	1b,3b;				\
			.previous;"				\
		: "=r"(__gu_err)				\
		: "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT)	\
	);							\
})

/*
 * Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail.
 */
static inline int clear_user(char *to, int size)
{
	if (size && access_ok(VERIFY_WRITE, to, size)) {
		__asm__ __volatile__ ("				\
				1:				\
					sb	r0, %2, r0;	\
					addik	%0, %0, -1;	\
					bneid	%0, 1b;		\
					addik	%2, %2, 1;	\
				2:				\
				.section __ex_table,\"a\";	\
				.word	1b,2b;			\
				.section .text;"		\
			: "=r"(size)				\
			: "0"(size), "r"(to)
		);
	}
	return size;
}

#define __copy_from_user(to, from, n)	copy_from_user((to), (from), (n))
#define __copy_from_user_inatomic(to, from, n) \
		copy_from_user((to), (from), (n))

#define copy_to_user(to, from, n)					\
	(access_ok(VERIFY_WRITE, (to), (n)) ?				\
		__copy_tofrom_user((void __user *)(to),			\
			(__force const void __user *)(from), (n))	\
		: -EFAULT)

#define __copy_to_user(to, from, n)	copy_to_user((to), (from), (n))
#define __copy_to_user_inatomic(to, from, n)	copy_to_user((to), (from), (n))

#define copy_from_user(to, from, n)					\
	(access_ok(VERIFY_READ, (from), (n)) ?				\
		__copy_tofrom_user((__force void __user *)(to),		\
			(void __user *)(from), (n))			\
		: -EFAULT)

extern int __strncpy_user(char *to, const char __user *from, int len);
extern int __strnlen_user(const char __user *sstr, int len);

#define strncpy_from_user(to, from, len)	\
		(access_ok(VERIFY_READ, from, 1) ?	\
			__strncpy_user(to, from, len) : -EFAULT)
#define strnlen_user(str, len)	\
		(access_ok(VERIFY_READ, str, 1) ? __strnlen_user(str, len) : 0)

#endif /* CONFIG_MMU */

extern unsigned long __copy_tofrom_user(void __user *to,
		const void __user *from, unsigned long size);

/*
 * 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;
};

#endif  /* __ASSEMBLY__ */
#endif /* __KERNEL__ */

#endif /* _ASM_MICROBLAZE_UACCESS_H */
Commit	Line	Data
2660663f	1	/*
0d6de953 MS	2	* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
0d6de953 MS	3	* Copyright (C) 2008-2009 PetaLogix
2660663f MS	4	* Copyright (C) 2006 Atmark Techno, Inc.
	5	*
	6	* This file is subject to the terms and conditions of the GNU General Public
	7	* License. See the file "COPYING" in the main directory of this archive
	8	* for more details.
	9	*/
	10
	11	#ifndef _ASM_MICROBLAZE_UACCESS_H
	12	#define _ASM_MICROBLAZE_UACCESS_H
	13
	14	#ifdef __KERNEL__
	15	#ifndef __ASSEMBLY__
	16
	17	#include <linux/kernel.h>
	18	#include <linux/errno.h>
	19	#include <linux/sched.h> /* RLIMIT_FSIZE */
	20	#include <linux/mm.h>
	21
	22	#include <asm/mmu.h>
	23	#include <asm/page.h>
	24	#include <asm/pgtable.h>
2660663f MS	25	#include <linux/string.h>
	26
	27	#define VERIFY_READ 0
	28	#define VERIFY_WRITE 1
	29
40db0834 MS	30	/*
	31	* On Microblaze the fs value is actually the top of the corresponding
	32	* address space.
	33	*
	34	* The fs value determines whether argument validity checking should be
	35	* performed or not. If get_fs() == USER_DS, checking is performed, with
	36	* get_fs() == KERNEL_DS, checking is bypassed.
	37	*
	38	* For historical reasons, these macros are grossly misnamed.
	39	*
	40	* For non-MMU arch like Microblaze, KERNEL_DS and USER_DS is equal.
	41	*/
	42	# define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
	43
	44	# ifndef CONFIG_MMU
	45	# define KERNEL_DS MAKE_MM_SEG(0)
	46	# define USER_DS KERNEL_DS
	47	# else
	48	# define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
	49	# define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
	50	# endif
	51
	52	# define get_ds() (KERNEL_DS)
	53	# define get_fs() (current_thread_info()->addr_limit)
	54	# define set_fs(val) (current_thread_info()->addr_limit = (val))
	55
	56	# define segment_eq(a, b) ((a).seg == (b).seg)
	57
	58
0d6de953 MS	59	#define __clear_user(addr, n) (memset((void *)(addr), 0, (n)), 0)
	60
	61	#ifndef CONFIG_MMU
	62
2660663f MS	63	extern int ___range_ok(unsigned long addr, unsigned long size);
	64
	65	#define __range_ok(addr, size) \
	66	___range_ok((unsigned long)(addr), (unsigned long)(size))
	67
	68	#define access_ok(type, addr, size) (__range_ok((addr), (size)) == 0)
	69	#define __access_ok(add, size) (__range_ok((addr), (size)) == 0)
	70
838d2406 AB	71	/* Undefined function to trigger linker error */
	72	extern int bad_user_access_length(void);
	73
2660663f	74	/* FIXME this is function for optimalization -> memcpy */
0d6de953 MS	75	#define __get_user(var, ptr) \
	76	({ \
	77	int __gu_err = 0; \
	78	switch (sizeof(*(ptr))) { \
	79	case 1: \
	80	case 2: \
	81	case 4: \
	82	(var) = *(ptr); \
	83	break; \
	84	case 8: \
	85	memcpy((void *) &(var), (ptr), 8); \
	86	break; \
	87	default: \
	88	(var) = 0; \
	89	__gu_err = __get_user_bad(); \
	90	break; \
	91	} \
	92	__gu_err; \
	93	})
2660663f MS	94
	95	#define __get_user_bad() (bad_user_access_length(), (-EFAULT))
	96
0d6de953	97	/* FIXME is not there defined __pu_val */
2660663f	98	#define __put_user(var, ptr) \
0d6de953 MS	99	({ \
	100	int __pu_err = 0; \
	101	switch (sizeof(*(ptr))) { \
	102	case 1: \
	103	case 2: \
	104	case 4: \
	105	*(ptr) = (var); \
	106	break; \
	107	case 8: { \
	108	typeof(*(ptr)) __pu_val = (var); \
	109	memcpy(ptr, &__pu_val, sizeof(__pu_val)); \
	110	} \
	111	break; \
	112	default: \
	113	__pu_err = __put_user_bad(); \
	114	break; \
	115	} \
	116	__pu_err; \
	117	})
2660663f MS	118
	119	#define __put_user_bad() (bad_user_access_length(), (-EFAULT))
	120
0d6de953 MS	121	#define put_user(x, ptr) __put_user((x), (ptr))
0d6de953 MS	122	#define get_user(x, ptr) __get_user((x), (ptr))
2660663f	123
0d6de953 MS	124	#define copy_to_user(to, from, n) (memcpy((to), (from), (n)), 0)
0d6de953 MS	125	#define copy_from_user(to, from, n) (memcpy((to), (from), (n)), 0)
2660663f	126
0d6de953 MS	127	#define __copy_to_user(to, from, n) (copy_to_user((to), (from), (n)))
	128	#define __copy_from_user(to, from, n) (copy_from_user((to), (from), (n)))
	129	#define __copy_to_user_inatomic(to, from, n) \
	130	(__copy_to_user((to), (from), (n)))
	131	#define __copy_from_user_inatomic(to, from, n) \
	132	(__copy_from_user((to), (from), (n)))
2660663f MS	133
	134	static inline unsigned long clear_user(void *addr, unsigned long size)
	135	{
	136	if (access_ok(VERIFY_WRITE, addr, size))
	137	size = __clear_user(addr, size);
	138	return size;
	139	}
	140
0d6de953	141	/* Returns 0 if exception not found and fixup otherwise. */
2660663f MS	142	extern unsigned long search_exception_table(unsigned long);
2660663f MS	143
0d6de953 MS	144	extern long strncpy_from_user(char dst, const char src, long count);
	145	extern long strnlen_user(const char *src, long count);
	146
	147	#else /* CONFIG_MMU */
	148
	149	/*
	150	* Address is valid if:
	151	* - "addr", "addr + size" and "size" are all below the limit
	152	*/
	153	#define access_ok(type, addr, size) \
	154	(get_fs().seg > (((unsigned long)(addr)) \| \
	155	(size) \| ((unsigned long)(addr) + (size))))
	156
	157	/* \|\| printk("access_ok failed for %s at 0x%08lx (size %d), seg 0x%08x\n",
	158	type?"WRITE":"READ",addr,size,get_fs().seg)) */
	159
	160	/*
	161	* All the __XXX versions macros/functions below do not perform
	162	* access checking. It is assumed that the necessary checks have been
	163	* already performed before the finction (macro) is called.
	164	*/
	165
	166	#define get_user(x, ptr) \
	167	({ \
	168	access_ok(VERIFY_READ, (ptr), sizeof(*(ptr))) \
	169	? __get_user((x), (ptr)) : -EFAULT; \
	170	})
	171
	172	#define put_user(x, ptr) \
	173	({ \
	174	access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) \
	175	? __put_user((x), (ptr)) : -EFAULT; \
	176	})
	177
	178	#define __get_user(x, ptr) \
	179	({ \
	180	unsigned long __gu_val; \
	181	/unsigned long __gu_ptr = (unsigned long)(ptr);/ \
	182	long __gu_err; \
	183	switch (sizeof(*(ptr))) { \
	184	case 1: \
	185	__get_user_asm("lbu", (ptr), __gu_val, __gu_err); \
	186	break; \
	187	case 2: \
	188	__get_user_asm("lhu", (ptr), __gu_val, __gu_err); \
	189	break; \
	190	case 4: \
	191	__get_user_asm("lw", (ptr), __gu_val, __gu_err); \
	192	break; \
	193	default: \
	194	__gu_val = 0; __gu_err = -EINVAL; \
	195	} \
	196	x = (__typeof__(*(ptr))) __gu_val; \
	197	__gu_err; \
	198	})
	199
	200	#define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \
	201	({ \
	202	__asm__ __volatile__ ( \
	203	"1:" insn " %1, %2, r0; \
	204	addk %0, r0, r0; \
	205	2: \
	206	.section .fixup,\"ax\"; \
	207	3: brid 2b; \
208	addik %0, r0, %3; \
209	.previous; \
210	.section __ex_table,\"a\"; \
211	.word 1b,3b; \
212	.previous;" \
213	: "=r"(__gu_err), "=r"(__gu_val) \
214	: "r"(__gu_ptr), "i"(-EFAULT) \
215	); \
216	})
217
218	#define __put_user(x, ptr) \
219	({ \
7bcb63b2	220	__typeof__(*(ptr)) volatile __gu_val = (x); \
0d6de953 MS	221	long __gu_err = 0; \
	222	switch (sizeof(__gu_val)) { \
	223	case 1: \
	224	__put_user_asm("sb", (ptr), __gu_val, __gu_err); \
	225	break; \
	226	case 2: \
	227	__put_user_asm("sh", (ptr), __gu_val, __gu_err); \
	228	break; \
	229	case 4: \
	230	__put_user_asm("sw", (ptr), __gu_val, __gu_err); \
	231	break; \
	232	case 8: \
	233	__put_user_asm_8((ptr), __gu_val, __gu_err); \
	234	break; \
	235	default: \
	236	__gu_err = -EINVAL; \
	237	} \
	238	__gu_err; \
	239	})
	240
	241	#define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err) \
	242	({ \
	243	__asm__ __volatile__ (" lwi %0, %1, 0; \
	244	1: swi %0, %2, 0; \
	245	lwi %0, %1, 4; \
	246	2: swi %0, %2, 4; \
	247	addk %0,r0,r0; \
	248	3: \
	249	.section .fixup,\"ax\"; \
	250	4: brid 3b; \
	251	addik %0, r0, %3; \
	252	.previous; \
	253	.section __ex_table,\"a\"; \
	254	.word 1b,4b,2b,4b; \
	255	.previous;" \
	256	: "=&r"(__gu_err) \
	257	: "r"(&__gu_val), \
	258	"r"(__gu_ptr), "i"(-EFAULT) \
	259	); \
	260	})
	261
	262	#define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \
	263	({ \
	264	__asm__ __volatile__ ( \
	265	"1:" insn " %1, %2, r0; \
	266	addk %0, r0, r0; \
	267	2: \
	268	.section .fixup,\"ax\"; \
	269	3: brid 2b; \
	270	addik %0, r0, %3; \
	271	.previous; \
	272	.section __ex_table,\"a\"; \
	273	.word 1b,3b; \
	274	.previous;" \
	275	: "=r"(__gu_err) \
	276	: "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \
	277	); \
	278	})
	279
	280	/*
	281	* Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail.
	282	*/
	283	static inline int clear_user(char *to, int size)
	284	{
285	if (size && access_ok(VERIFY_WRITE, to, size)) {
286	__asm__ __volatile__ (" \
287	1: \
288	sb r0, %2, r0; \
289	addik %0, %0, -1; \
290	bneid %0, 1b; \
291	addik %2, %2, 1; \
292	2: \
293	.section __ex_table,\"a\"; \
294	.word 1b,2b; \
295	.section .text;" \
296	: "=r"(size) \
297	: "0"(size), "r"(to)
298	);
299	}
300	return size;
301	}
302
95dfbbe4 JW	303	#define __copy_from_user(to, from, n) copy_from_user((to), (from), (n))
	304	#define __copy_from_user_inatomic(to, from, n) \
	305	copy_from_user((to), (from), (n))
0d6de953 MS	306
	307	#define copy_to_user(to, from, n) \
	308	(access_ok(VERIFY_WRITE, (to), (n)) ? \
	309	__copy_tofrom_user((void __user *)(to), \
	310	(__force const void __user *)(from), (n)) \
	311	: -EFAULT)
	312
	313	#define __copy_to_user(to, from, n) copy_to_user((to), (from), (n))
	314	#define __copy_to_user_inatomic(to, from, n) copy_to_user((to), (from), (n))
	315
	316	#define copy_from_user(to, from, n) \
	317	(access_ok(VERIFY_READ, (from), (n)) ? \
	318	__copy_tofrom_user((__force void __user *)(to), \
	319	(void __user *)(from), (n)) \
	320	: -EFAULT)
	321
0d6de953 MS	322	extern int __strncpy_user(char to, const char __user from, int len);
	323	extern int __strnlen_user(const char __user *sstr, int len);
	324
	325	#define strncpy_from_user(to, from, len) \
	326	(access_ok(VERIFY_READ, from, 1) ? \
	327	__strncpy_user(to, from, len) : -EFAULT)
	328	#define strnlen_user(str, len) \
	329	(access_ok(VERIFY_READ, str, 1) ? __strnlen_user(str, len) : 0)
2660663f	330
0d6de953	331	#endif /* CONFIG_MMU */
2660663f	332
95dfbbe4 JW	333	extern unsigned long __copy_tofrom_user(void __user *to,
	334	const void __user *from, unsigned long size);
	335
2660663f MS	336	/*
	337	* The exception table consists of pairs of addresses: the first is the
	338	* address of an instruction that is allowed to fault, and the second is
	339	* the address at which the program should continue. No registers are
	340	* modified, so it is entirely up to the continuation code to figure out
	341	* what to do.
	342	*
	343	* All the routines below use bits of fixup code that are out of line
	344	* with the main instruction path. This means when everything is well,
	345	* we don't even have to jump over them. Further, they do not intrude
	346	* on our cache or tlb entries.
	347	*/
	348	struct exception_table_entry {
	349	unsigned long insn, fixup;
	350	};
	351
	352	#endif /* __ASSEMBLY__ */
	353	#endif /* __KERNEL__ */
	354
	355	#endif /* _ASM_MICROBLAZE_UACCESS_H */