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

/*
 * OpenRISC Linux
 *
 * Linux architectural port borrowing liberally from similar works of
 * others.  All original copyrights apply as per the original source
 * declaration.
 *
 * OpenRISC implementation:
 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
 * et al.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#ifndef __ASM_OPENRISC_UACCESS_H
#define __ASM_OPENRISC_UACCESS_H

/*
 * User space memory access functions
 */
#include <linux/errno.h>
#include <linux/thread_info.h>
#include <linux/prefetch.h>
#include <linux/string.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.
 */

/* addr_limit is the maximum accessible address for the task. we misuse
 * the KERNEL_DS and USER_DS values to both assign and compare the
 * addr_limit values through the equally misnamed get/set_fs macros.
 * (see above)
 */

#define KERNEL_DS	(~0UL)
#define get_ds()	(KERNEL_DS)

#define USER_DS		(TASK_SIZE)
#define get_fs()	(current_thread_info()->addr_limit)
#define set_fs(x)	(current_thread_info()->addr_limit = (x))

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

/* Ensure that the range from addr to addr+size is all within the process'
 * address space
 */
#define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs()-size))

/* Ensure that addr is below task's addr_limit */
#define __addr_ok(addr) ((unsigned long) addr < get_fs())

#define access_ok(type, addr, size) \
	__range_ok((unsigned long)addr, (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;
};

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

/*
 * 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).
 *
 * As we use the same address space for kernel and user data on the
 * PowerPC, we can just do these as direct assignments.  (Of course, the
 * exception handling means that it's no longer "just"...)
 */
#define get_user(x, ptr) \
	__get_user_check((x), (ptr), sizeof(*(ptr)))
#define put_user(x, ptr) \
	__put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))

#define __get_user(x, ptr) \
	__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
#define __put_user(x, ptr) \
	__put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))

extern long __put_user_bad(void);

#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)) *__pu_addr = (ptr);				\
	if (access_ok(VERIFY_WRITE, __pu_addr, size))			\
		__put_user_size((x), __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(x, ptr, retval, "l.sb"); break;		\
	case 2: __put_user_asm(x, ptr, retval, "l.sh"); break;		\
	case 4: __put_user_asm(x, ptr, retval, "l.sw"); break;		\
	case 8: __put_user_asm2(x, ptr, retval); break;			\
	default: __put_user_bad();					\
	}								\
} while (0)

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

/*
 * 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.
 */
#define __put_user_asm(x, addr, err, op)			\
	__asm__ __volatile__(					\
		"1:	"op" 0(%2),%1\n"			\
		"2:\n"						\
		".section .fixup,\"ax\"\n"			\
		"3:	l.addi %0,r0,%3\n"			\
		"	l.j 2b\n"				\
		"	l.nop\n"				\
		".previous\n"					\
		".section __ex_table,\"a\"\n"			\
		"	.align 2\n"				\
		"	.long 1b,3b\n"				\
		".previous"					\
		: "=r"(err)					\
		: "r"(x), "r"(addr), "i"(-EFAULT), "0"(err))

#define __put_user_asm2(x, addr, err)				\
	__asm__ __volatile__(					\
		"1:	l.sw 0(%2),%1\n"			\
		"2:	l.sw 4(%2),%H1\n"			\
		"3:\n"						\
		".section .fixup,\"ax\"\n"			\
		"4:	l.addi %0,r0,%3\n"			\
		"	l.j 3b\n"				\
		"	l.nop\n"				\
		".previous\n"					\
		".section __ex_table,\"a\"\n"			\
		"	.align 2\n"				\
		"	.long 1b,4b\n"				\
		"	.long 2b,4b\n"				\
		".previous"					\
		: "=r"(err)					\
		: "r"(x), "r"(addr), "i"(-EFAULT), "0"(err))

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

#define __get_user_check(x, ptr, size)					\
({									\
	long __gu_err = -EFAULT, __gu_val = 0;				\
	const __typeof__(*(ptr)) * __gu_addr = (ptr);			\
	if (access_ok(VERIFY_READ, __gu_addr, size))			\
		__get_user_size(__gu_val, __gu_addr, (size), __gu_err);	\
	(x) = (__force __typeof__(*(ptr)))__gu_val;			\
	__gu_err;							\
})

extern long __get_user_bad(void);

#define __get_user_size(x, ptr, size, retval)				\
do {									\
	retval = 0;							\
	switch (size) {							\
	case 1: __get_user_asm(x, ptr, retval, "l.lbz"); break;		\
	case 2: __get_user_asm(x, ptr, retval, "l.lhz"); break;		\
	case 4: __get_user_asm(x, ptr, retval, "l.lwz"); break;		\
	case 8: __get_user_asm2(x, ptr, retval);			\
	default: (x) = __get_user_bad();				\
	}								\
} while (0)

#define __get_user_asm(x, addr, err, op)		\
	__asm__ __volatile__(				\
		"1:	"op" %1,0(%2)\n"		\
		"2:\n"					\
		".section .fixup,\"ax\"\n"		\
		"3:	l.addi %0,r0,%3\n"		\
		"	l.addi %1,r0,0\n"		\
		"	l.j 2b\n"			\
		"	l.nop\n"			\
		".previous\n"				\
		".section __ex_table,\"a\"\n"		\
		"	.align 2\n"			\
		"	.long 1b,3b\n"			\
		".previous"				\
		: "=r"(err), "=r"(x)			\
		: "r"(addr), "i"(-EFAULT), "0"(err))

#define __get_user_asm2(x, addr, err)			\
	__asm__ __volatile__(				\
		"1:	l.lwz %1,0(%2)\n"		\
		"2:	l.lwz %H1,4(%2)\n"		\
		"3:\n"					\
		".section .fixup,\"ax\"\n"		\
		"4:	l.addi %0,r0,%3\n"		\
		"	l.addi %1,r0,0\n"		\
		"	l.addi %H1,r0,0\n"		\
		"	l.j 3b\n"			\
		"	l.nop\n"			\
		".previous\n"				\
		".section __ex_table,\"a\"\n"		\
		"	.align 2\n"			\
		"	.long 1b,4b\n"			\
		"	.long 2b,4b\n"			\
		".previous"				\
		: "=r"(err), "=&r"(x)			\
		: "r"(addr), "i"(-EFAULT), "0"(err))

/* more complex routines */

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

#define __copy_from_user(to, from, size) \
	__copy_tofrom_user(to, from, size)
#define __copy_to_user(to, from, size) \
	__copy_tofrom_user(to, from, size)

#define __copy_to_user_inatomic __copy_to_user
#define __copy_from_user_inatomic __copy_from_user

static inline unsigned long
copy_from_user(void *to, const void *from, unsigned long n)
{
	unsigned long res = n;

	if (likely(access_ok(VERIFY_READ, from, n)))
		res = __copy_tofrom_user(to, from, n);
	if (unlikely(res))
		memset(to + (n - res), 0, res);
	return res;
}

static inline unsigned long
copy_to_user(void *to, const void *from, unsigned long n)
{
	if (likely(access_ok(VERIFY_WRITE, to, n)))
		n = __copy_tofrom_user(to, from, n);
	return n;
}

extern unsigned long __clear_user(void *addr, unsigned long size);

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

#define user_addr_max() \
	(segment_eq(get_fs(), USER_DS) ? TASK_SIZE : ~0UL)

extern long strncpy_from_user(char *dest, const char __user *src, long count);

extern __must_check long strlen_user(const char __user *str);
extern __must_check long strnlen_user(const char __user *str, long n);

#endif /* __ASM_OPENRISC_UACCESS_H */
Commit	Line	Data
61e85e36 JB	1	/*
	2	* OpenRISC Linux
	3	*
	4	* Linux architectural port borrowing liberally from similar works of
	5	* others. All original copyrights apply as per the original source
	6	* declaration.
	7	*
	8	* OpenRISC implementation:
	9	* Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
	10	* Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
	11	* et al.
	12	*
	13	* This program is free software; you can redistribute it and/or modify
	14	* it under the terms of the GNU General Public License as published by
	15	* the Free Software Foundation; either version 2 of the License, or
	16	* (at your option) any later version.
	17	*/
	18
	19	#ifndef __ASM_OPENRISC_UACCESS_H
	20	#define __ASM_OPENRISC_UACCESS_H
	21
	22	/*
	23	* User space memory access functions
	24	*/
	25	#include <linux/errno.h>
	26	#include <linux/thread_info.h>
	27	#include <linux/prefetch.h>
	28	#include <linux/string.h>
61e85e36 JB	29	#include <asm/page.h>
	30
	31	#define VERIFY_READ 0
	32	#define VERIFY_WRITE 1
	33
	34	/*
	35	* The fs value determines whether argument validity checking should be
	36	* performed or not. If get_fs() == USER_DS, checking is performed, with
	37	* get_fs() == KERNEL_DS, checking is bypassed.
	38	*
	39	* For historical reasons, these macros are grossly misnamed.
	40	*/
	41
	42	/* addr_limit is the maximum accessible address for the task. we misuse
	43	* the KERNEL_DS and USER_DS values to both assign and compare the
	44	* addr_limit values through the equally misnamed get/set_fs macros.
	45	* (see above)
	46	*/
	47
	48	#define KERNEL_DS (~0UL)
	49	#define get_ds() (KERNEL_DS)
	50
	51	#define USER_DS (TASK_SIZE)
	52	#define get_fs() (current_thread_info()->addr_limit)
	53	#define set_fs(x) (current_thread_info()->addr_limit = (x))
	54
	55	#define segment_eq(a, b) ((a) == (b))
	56
	57	/* Ensure that the range from addr to addr+size is all within the process'
	58	* address space
	59	*/
	60	#define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs()-size))
	61
	62	/* Ensure that addr is below task's addr_limit */
	63	#define __addr_ok(addr) ((unsigned long) addr < get_fs())
	64
	65	#define access_ok(type, addr, size) \
	66	__range_ok((unsigned long)addr, (unsigned long)size)
	67
	68	/*
	69	* The exception table consists of pairs of addresses: the first is the
	70	* address of an instruction that is allowed to fault, and the second is
	71	* the address at which the program should continue. No registers are
	72	* modified, so it is entirely up to the continuation code to figure out
	73	* what to do.
	74	*
	75	* All the routines below use bits of fixup code that are out of line
	76	* with the main instruction path. This means when everything is well,
	77	* we don't even have to jump over them. Further, they do not intrude
	78	* on our cache or tlb entries.
	79	*/
	80
	81	struct exception_table_entry {
	82	unsigned long insn, fixup;
	83	};
	84
	85	/* Returns 0 if exception not found and fixup otherwise. */
	86	extern unsigned long search_exception_table(unsigned long);
	87	extern void sort_exception_table(void);
	88
	89	/*
	90	* These are the main single-value transfer routines. They automatically
	91	* use the right size if we just have the right pointer type.
	92	*
93	* This gets kind of ugly. We want to return _two_ values in "get_user()"
94	* and yet we don't want to do any pointers, because that is too much
95	* of a performance impact. Thus we have a few rather ugly macros here,
96	* and hide all the uglyness from the user.
97	*
98	* The "__xxx" versions of the user access functions are versions that
99	* do not verify the address space, that must have been done previously
100	* with a separate "access_ok()" call (this is used when we do multiple
101	* accesses to the same area of user memory).
102	*
103	* As we use the same address space for kernel and user data on the
104	* PowerPC, we can just do these as direct assignments. (Of course, the
105	* exception handling means that it's no longer "just"...)
106	*/
107	#define get_user(x, ptr) \
108	__get_user_check((x), (ptr), sizeof(*(ptr)))
109	#define put_user(x, ptr) \
110	__put_user_check((__typeof__((ptr)))(x), (ptr), sizeof((ptr)))
111
112	#define __get_user(x, ptr) \
113	__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
114	#define __put_user(x, ptr) \
115	__put_user_nocheck((__typeof__((ptr)))(x), (ptr), sizeof((ptr)))
116
117	extern long __put_user_bad(void);
118
119	#define __put_user_nocheck(x, ptr, size) \
120	({ \
121	long __pu_err; \
122	__put_user_size((x), (ptr), (size), __pu_err); \
123	__pu_err; \
124	})
125
126	#define __put_user_check(x, ptr, size) \
127	({ \
128	long __pu_err = -EFAULT; \
129	__typeof__((ptr)) __pu_addr = (ptr); \
130	if (access_ok(VERIFY_WRITE, __pu_addr, size)) \
131	__put_user_size((x), __pu_addr, (size), __pu_err); \
132	__pu_err; \
133	})
134
135	#define __put_user_size(x, ptr, size, retval) \
136	do { \
137	retval = 0; \
138	switch (size) { \
139	case 1: __put_user_asm(x, ptr, retval, "l.sb"); break; \
140	case 2: __put_user_asm(x, ptr, retval, "l.sh"); break; \
141	case 4: __put_user_asm(x, ptr, retval, "l.sw"); break; \
142	case 8: __put_user_asm2(x, ptr, retval); break; \
143	default: __put_user_bad(); \
144	} \
145	} while (0)
146
147	struct __large_struct {
148	unsigned long buf[100];
149	};
150	#define __m(x) ((struct __large_struct )(x))
151
152	/*
153	* We don't tell gcc that we are accessing memory, but this is OK
154	* because we do not write to any memory gcc knows about, so there
155	* are no aliasing issues.
156	*/
157	#define __put_user_asm(x, addr, err, op) \
158	__asm__ __volatile__( \
159	"1: "op" 0(%2),%1\n" \
160	"2:\n" \
161	".section .fixup,\"ax\"\n" \
162	"3: l.addi %0,r0,%3\n" \
163	" l.j 2b\n" \
164	" l.nop\n" \
165	".previous\n" \
166	".section __ex_table,\"a\"\n" \
167	" .align 2\n" \
168	" .long 1b,3b\n" \
169	".previous" \
170	: "=r"(err) \
171	: "r"(x), "r"(addr), "i"(-EFAULT), "0"(err))
172
173	#define __put_user_asm2(x, addr, err) \
174	__asm__ __volatile__( \
175	"1: l.sw 0(%2),%1\n" \
176	"2: l.sw 4(%2),%H1\n" \
177	"3:\n" \
178	".section .fixup,\"ax\"\n" \
179	"4: l.addi %0,r0,%3\n" \
180	" l.j 3b\n" \
181	" l.nop\n" \
182	".previous\n" \
183	".section __ex_table,\"a\"\n" \
184	" .align 2\n" \
185	" .long 1b,4b\n" \
186	" .long 2b,4b\n" \
187	".previous" \
188	: "=r"(err) \
189	: "r"(x), "r"(addr), "i"(-EFAULT), "0"(err))
190
191	#define __get_user_nocheck(x, ptr, size) \
192	({ \
193	long __gu_err, __gu_val; \
194	__get_user_size(__gu_val, (ptr), (size), __gu_err); \
582a6783	195	(x) = (__force __typeof__(*(ptr)))__gu_val; \
61e85e36 JB	196	__gu_err; \
	197	})
	198
	199	#define __get_user_check(x, ptr, size) \
	200	({ \
	201	long __gu_err = -EFAULT, __gu_val = 0; \
	202	const __typeof__((ptr)) __gu_addr = (ptr); \
	203	if (access_ok(VERIFY_READ, __gu_addr, size)) \
	204	__get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
582a6783	205	(x) = (__force __typeof__(*(ptr)))__gu_val; \
61e85e36 JB	206	__gu_err; \
	207	})
	208
	209	extern long __get_user_bad(void);
	210
	211	#define __get_user_size(x, ptr, size, retval) \
	212	do { \
	213	retval = 0; \
	214	switch (size) { \
	215	case 1: __get_user_asm(x, ptr, retval, "l.lbz"); break; \
	216	case 2: __get_user_asm(x, ptr, retval, "l.lhz"); break; \
	217	case 4: __get_user_asm(x, ptr, retval, "l.lwz"); break; \
	218	case 8: __get_user_asm2(x, ptr, retval); \
	219	default: (x) = __get_user_bad(); \
	220	} \
	221	} while (0)
	222
	223	#define __get_user_asm(x, addr, err, op) \
	224	__asm__ __volatile__( \
	225	"1: "op" %1,0(%2)\n" \
	226	"2:\n" \
	227	".section .fixup,\"ax\"\n" \
	228	"3: l.addi %0,r0,%3\n" \
	229	" l.addi %1,r0,0\n" \
	230	" l.j 2b\n" \
	231	" l.nop\n" \
	232	".previous\n" \
	233	".section __ex_table,\"a\"\n" \
	234	" .align 2\n" \
	235	" .long 1b,3b\n" \
	236	".previous" \
	237	: "=r"(err), "=r"(x) \
	238	: "r"(addr), "i"(-EFAULT), "0"(err))
	239
	240	#define __get_user_asm2(x, addr, err) \
	241	__asm__ __volatile__( \
	242	"1: l.lwz %1,0(%2)\n" \
	243	"2: l.lwz %H1,4(%2)\n" \
	244	"3:\n" \
	245	".section .fixup,\"ax\"\n" \
	246	"4: l.addi %0,r0,%3\n" \
	247	" l.addi %1,r0,0\n" \
	248	" l.addi %H1,r0,0\n" \
	249	" l.j 3b\n" \
	250	" l.nop\n" \
	251	".previous\n" \
	252	".section __ex_table,\"a\"\n" \
	253	" .align 2\n" \
	254	" .long 1b,4b\n" \
	255	" .long 2b,4b\n" \
	256	".previous" \
	257	: "=r"(err), "=&r"(x) \
	258	: "r"(addr), "i"(-EFAULT), "0"(err))
	259
	260	/* more complex routines */
	261
	262	extern unsigned long __must_check
	263	__copy_tofrom_user(void to, const void from, unsigned long size);
	264
	265	#define __copy_from_user(to, from, size) \
	266	__copy_tofrom_user(to, from, size)
	267	#define __copy_to_user(to, from, size) \
	268	__copy_tofrom_user(to, from, size)
	269
270	#define __copy_to_user_inatomic __copy_to_user
271	#define __copy_from_user_inatomic __copy_from_user
272
273	static inline unsigned long
274	copy_from_user(void to, const void from, unsigned long n)
275	{
acb2505d AV	276	unsigned long res = n;
	277
	278	if (likely(access_ok(VERIFY_READ, from, n)))
8e4b7205	279	res = __copy_tofrom_user(to, from, n);
acb2505d AV	280	if (unlikely(res))
	281	memset(to + (n - res), 0, res);
	282	return res;
61e85e36 JB	283	}
	284
	285	static inline unsigned long
	286	copy_to_user(void to, const void from, unsigned long n)
	287	{
acb2505d AV	288	if (likely(access_ok(VERIFY_WRITE, to, n)))
acb2505d AV	289	n = __copy_tofrom_user(to, from, n);
61e85e36 JB	290	return n;
	291	}
	292
	293	extern unsigned long __clear_user(void *addr, unsigned long size);
	294
	295	static inline __must_check unsigned long
	296	clear_user(void *addr, unsigned long size)
	297	{
acb2505d AV	298	if (likely(access_ok(VERIFY_WRITE, addr, size)))
acb2505d AV	299	size = __clear_user(addr, size);
61e85e36 JB	300	return size;
	301	}
	302
603d6637 JB	303	#define user_addr_max() \
603d6637 JB	304	(segment_eq(get_fs(), USER_DS) ? TASK_SIZE : ~0UL)
61e85e36	305
603d6637	306	extern long strncpy_from_user(char dest, const char __user src, long count);
61e85e36	307
b48b2c3e JB	308	extern __must_check long strlen_user(const char __user *str);
b48b2c3e JB	309	extern __must_check long strnlen_user(const char __user *str, long n);
61e85e36 JB	310
61e85e36 JB	311	#endif /* __ASM_OPENRISC_UACCESS_H */