[mirror_ubuntu-focal-kernel.git] / arch / nios2 / include / asm / uaccess.h

/*
 * User space memory access functions for Nios II
 *
 * Copyright (C) 2010-2011, Tobias Klauser <tklauser@distanz.ch>
 * Copyright (C) 2009, Wind River Systems Inc
 *   Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
 *
 * 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_NIOS2_UACCESS_H
#define _ASM_NIOS2_UACCESS_H

#include <linux/string.h>

#include <asm/page.h>

#include <asm/extable.h>

/*
 * Segment stuff
 */
#define MAKE_MM_SEG(s)		((mm_segment_t) { (s) })
#define USER_DS			MAKE_MM_SEG(0x80000000UL)
#define KERNEL_DS		MAKE_MM_SEG(0)

#define get_ds()		(KERNEL_DS)

#define get_fs()		(current_thread_info()->addr_limit)
#define set_fs(seg)		(current_thread_info()->addr_limit = (seg))

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

#define __access_ok(addr, len)			\
	(((signed long)(((long)get_fs().seg) &	\
		((long)(addr) | (((long)(addr)) + (len)) | (len)))) == 0)

#define access_ok(addr, len)		\
	likely(__access_ok((unsigned long)(addr), (unsigned long)(len)))

# define __EX_TABLE_SECTION	".section __ex_table,\"a\"\n"

#define user_addr_max() (uaccess_kernel() ? ~0UL : TASK_SIZE)

/*
 * Zero Userspace
 */

static inline unsigned long __must_check __clear_user(void __user *to,
						      unsigned long n)
{
	__asm__ __volatile__ (
		"1:     stb     zero, 0(%1)\n"
		"       addi    %0, %0, -1\n"
		"       addi    %1, %1, 1\n"
		"       bne     %0, zero, 1b\n"
		"2:\n"
		__EX_TABLE_SECTION
		".word  1b, 2b\n"
		".previous\n"
		: "=r" (n), "=r" (to)
		: "0" (n), "1" (to)
	);

	return n;
}

static inline unsigned long __must_check clear_user(void __user *to,
						    unsigned long n)
{
	if (!access_ok(to, n))
		return n;
	return __clear_user(to, n);
}

extern unsigned long
raw_copy_from_user(void *to, const void __user *from, unsigned long n);
extern unsigned long
raw_copy_to_user(void __user *to, const void *from, unsigned long n);
#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER

extern long strncpy_from_user(char *__to, const char __user *__from,
			      long __len);
extern __must_check long strlen_user(const char __user *str);
extern __must_check long strnlen_user(const char __user *s, long n);

/* Optimized macros */
#define __get_user_asm(val, insn, addr, err)				\
{									\
	__asm__ __volatile__(						\
	"       movi    %0, %3\n"					\
	"1:   " insn " %1, 0(%2)\n"					\
	"       movi     %0, 0\n"					\
	"2:\n"								\
	"       .section __ex_table,\"a\"\n"				\
	"       .word 1b, 2b\n"						\
	"       .previous"						\
	: "=&r" (err), "=r" (val)					\
	: "r" (addr), "i" (-EFAULT));					\
}

#define __get_user_unknown(val, size, ptr, err) do {			\
	err = 0;							\
	if (__copy_from_user(&(val), ptr, size)) {			\
		err = -EFAULT;						\
	}								\
	} while (0)

#define __get_user_common(val, size, ptr, err)				\
do {									\
	switch (size) {							\
	case 1:								\
		__get_user_asm(val, "ldbu", ptr, err);			\
		break;							\
	case 2:								\
		__get_user_asm(val, "ldhu", ptr, err);			\
		break;							\
	case 4:								\
		__get_user_asm(val, "ldw", ptr, err);			\
		break;							\
	default:							\
		__get_user_unknown(val, size, ptr, err);		\
		break;							\
	}								\
} while (0)

#define __get_user(x, ptr)						\
	({								\
	long __gu_err = -EFAULT;					\
	const __typeof__(*(ptr)) __user *__gu_ptr = (ptr);		\
	unsigned long __gu_val = 0;					\
	__get_user_common(__gu_val, sizeof(*(ptr)), __gu_ptr, __gu_err);\
	(x) = (__force __typeof__(x))__gu_val;				\
	__gu_err;							\
	})

#define get_user(x, ptr)						\
({									\
	long __gu_err = -EFAULT;					\
	const __typeof__(*(ptr)) __user *__gu_ptr = (ptr);		\
	unsigned long __gu_val = 0;					\
	if (access_ok( __gu_ptr, sizeof(*__gu_ptr)))	\
		__get_user_common(__gu_val, sizeof(*__gu_ptr),		\
			__gu_ptr, __gu_err);				\
	(x) = (__force __typeof__(x))__gu_val;				\
	__gu_err;							\
})

#define __put_user_asm(val, insn, ptr, err)				\
{									\
	__asm__ __volatile__(						\
	"       movi    %0, %3\n"					\
	"1:   " insn " %1, 0(%2)\n"					\
	"       movi     %0, 0\n"					\
	"2:\n"								\
	"       .section __ex_table,\"a\"\n"				\
	"       .word 1b, 2b\n"						\
	"       .previous\n"						\
	: "=&r" (err)							\
	: "r" (val), "r" (ptr), "i" (-EFAULT));				\
}

#define put_user(x, ptr)						\
({									\
	long __pu_err = -EFAULT;					\
	__typeof__(*(ptr)) __user *__pu_ptr = (ptr);			\
	__typeof__(*(ptr)) __pu_val = (__typeof(*ptr))(x);		\
	if (access_ok(__pu_ptr, sizeof(*__pu_ptr))) {	\
		switch (sizeof(*__pu_ptr)) {				\
		case 1:							\
			__put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \
			break;						\
		case 2:							\
			__put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \
			break;						\
		case 4:							\
			__put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \
			break;						\
		default:						\
			/* XXX: This looks wrong... */			\
			__pu_err = 0;					\
			if (copy_to_user(__pu_ptr, &(__pu_val),		\
				sizeof(*__pu_ptr)))			\
				__pu_err = -EFAULT;			\
			break;						\
		}							\
	}								\
	__pu_err;							\
})

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

#endif /* _ASM_NIOS2_UACCESS_H */
Commit	Line	Data
5ccc6af5 LFT	1	/*
	2	* User space memory access functions for Nios II
	3	*
	4	* Copyright (C) 2010-2011, Tobias Klauser <tklauser@distanz.ch>
	5	* Copyright (C) 2009, Wind River Systems Inc
	6	* Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
	7	*
	8	* This file is subject to the terms and conditions of the GNU General Public
	9	* License. See the file "COPYING" in the main directory of this archive
	10	* for more details.
	11	*/
	12
	13	#ifndef _ASM_NIOS2_UACCESS_H
	14	#define _ASM_NIOS2_UACCESS_H
	15
5ccc6af5 LFT	16	#include <linux/string.h>
	17
	18	#include <asm/page.h>
	19
981db65b	20	#include <asm/extable.h>
5ccc6af5 LFT	21
	22	/*
	23	* Segment stuff
	24	*/
	25	#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
	26	#define USER_DS MAKE_MM_SEG(0x80000000UL)
	27	#define KERNEL_DS MAKE_MM_SEG(0)
	28
	29	#define get_ds() (KERNEL_DS)
	30
	31	#define get_fs() (current_thread_info()->addr_limit)
	32	#define set_fs(seg) (current_thread_info()->addr_limit = (seg))
	33
	34	#define segment_eq(a, b) ((a).seg == (b).seg)
	35
	36	#define __access_ok(addr, len) \
	37	(((signed long)(((long)get_fs().seg) & \
	38	((long)(addr) \| (((long)(addr)) + (len)) \| (len)))) == 0)
	39
96d4f267	40	#define access_ok(addr, len) \
5ccc6af5 LFT	41	likely(__access_ok((unsigned long)(addr), (unsigned long)(len)))
	42
	43	# define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n"
	44
7f1e6141 LFT	45	#define user_addr_max() (uaccess_kernel() ? ~0UL : TASK_SIZE)
7f1e6141 LFT	46
5ccc6af5 LFT	47	/*
	48	* Zero Userspace
	49	*/
	50
	51	static inline unsigned long __must_check __clear_user(void __user *to,
	52	unsigned long n)
	53	{
	54	__asm__ __volatile__ (
	55	"1: stb zero, 0(%1)\n"
	56	" addi %0, %0, -1\n"
	57	" addi %1, %1, 1\n"
	58	" bne %0, zero, 1b\n"
	59	"2:\n"
	60	__EX_TABLE_SECTION
	61	".word 1b, 2b\n"
	62	".previous\n"
	63	: "=r" (n), "=r" (to)
	64	: "0" (n), "1" (to)
	65	);
	66
	67	return n;
	68	}
	69
	70	static inline unsigned long __must_check clear_user(void __user *to,
	71	unsigned long n)
	72	{
96d4f267	73	if (!access_ok(to, n))
5ccc6af5 LFT	74	return n;
	75	return __clear_user(to, n);
	76	}
	77
de51d6cc AV	78	extern unsigned long
	79	raw_copy_from_user(void to, const void __user from, unsigned long n);
	80	extern unsigned long
	81	raw_copy_to_user(void __user to, const void from, unsigned long n);
	82	#define INLINE_COPY_FROM_USER
	83	#define INLINE_COPY_TO_USER
5ccc6af5 LFT	84
5ccc6af5 LFT	85	extern long strncpy_from_user(char __to, const char __user __from,
7f1e6141 LFT	86	long __len);
	87	extern __must_check long strlen_user(const char __user *str);
	88	extern __must_check long strnlen_user(const char __user *s, long n);
5ccc6af5	89
5ccc6af5 LFT	90	/* Optimized macros */
	91	#define __get_user_asm(val, insn, addr, err) \
	92	{ \
	93	__asm__ __volatile__( \
	94	" movi %0, %3\n" \
	95	"1: " insn " %1, 0(%2)\n" \
	96	" movi %0, 0\n" \
	97	"2:\n" \
	98	" .section __ex_table,\"a\"\n" \
	99	" .word 1b, 2b\n" \
	100	" .previous" \
	101	: "=&r" (err), "=r" (val) \
	102	: "r" (addr), "i" (-EFAULT)); \
	103	}
	104
	105	#define __get_user_unknown(val, size, ptr, err) do { \
	106	err = 0; \
2e29f50a	107	if (__copy_from_user(&(val), ptr, size)) { \
5ccc6af5 LFT	108	err = -EFAULT; \
	109	} \
	110	} while (0)
	111
	112	#define __get_user_common(val, size, ptr, err) \
	113	do { \
	114	switch (size) { \
	115	case 1: \
	116	__get_user_asm(val, "ldbu", ptr, err); \
	117	break; \
	118	case 2: \
	119	__get_user_asm(val, "ldhu", ptr, err); \
	120	break; \
	121	case 4: \
	122	__get_user_asm(val, "ldw", ptr, err); \
	123	break; \
	124	default: \
	125	__get_user_unknown(val, size, ptr, err); \
	126	break; \
	127	} \
	128	} while (0)
	129
	130	#define __get_user(x, ptr) \
	131	({ \
	132	long __gu_err = -EFAULT; \
	133	const __typeof__((ptr)) __user __gu_ptr = (ptr); \
2e29f50a	134	unsigned long __gu_val = 0; \
5ccc6af5	135	__get_user_common(__gu_val, sizeof(*(ptr)), __gu_ptr, __gu_err);\
f1f2eac9	136	(x) = (__force __typeof__(x))__gu_val; \
5ccc6af5 LFT	137	__gu_err; \
	138	})
	139
	140	#define get_user(x, ptr) \
	141	({ \
	142	long __gu_err = -EFAULT; \
	143	const __typeof__((ptr)) __user __gu_ptr = (ptr); \
	144	unsigned long __gu_val = 0; \
96d4f267	145	if (access_ok( __gu_ptr, sizeof(*__gu_ptr))) \
5ccc6af5 LFT	146	__get_user_common(__gu_val, sizeof(*__gu_ptr), \
5ccc6af5 LFT	147	__gu_ptr, __gu_err); \
f1f2eac9	148	(x) = (__force __typeof__(x))__gu_val; \
5ccc6af5 LFT	149	__gu_err; \
	150	})
	151
	152	#define __put_user_asm(val, insn, ptr, err) \
	153	{ \
	154	__asm__ __volatile__( \
	155	" movi %0, %3\n" \
	156	"1: " insn " %1, 0(%2)\n" \
	157	" movi %0, 0\n" \
	158	"2:\n" \
	159	" .section __ex_table,\"a\"\n" \
	160	" .word 1b, 2b\n" \
	161	" .previous\n" \
	162	: "=&r" (err) \
	163	: "r" (val), "r" (ptr), "i" (-EFAULT)); \
	164	}
	165
	166	#define put_user(x, ptr) \
	167	({ \
	168	long __pu_err = -EFAULT; \
	169	__typeof__((ptr)) __user __pu_ptr = (ptr); \
	170	__typeof__((ptr)) __pu_val = (__typeof(ptr))(x); \
96d4f267	171	if (access_ok(__pu_ptr, sizeof(*__pu_ptr))) { \
5ccc6af5 LFT	172	switch (sizeof(*__pu_ptr)) { \
	173	case 1: \
	174	__put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \
	175	break; \
	176	case 2: \
	177	__put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \
	178	break; \
	179	case 4: \
	180	__put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \
	181	break; \
	182	default: \
	183	/* XXX: This looks wrong... */ \
	184	__pu_err = 0; \
	185	if (copy_to_user(__pu_ptr, &(__pu_val), \
	186	sizeof(*__pu_ptr))) \
	187	__pu_err = -EFAULT; \
	188	break; \
	189	} \
	190	} \
	191	__pu_err; \
	192	})
	193
	194	#define __put_user(x, ptr) put_user(x, ptr)
	195
	196	#endif /* _ASM_NIOS2_UACCESS_H */