/*
 * 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.
 *
 * Copyright (C) 1996, 1997, 1998, 1999, 2000 by Ralf Baechle
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 */
#ifndef _ASM_UACCESS_H
#define _ASM_UACCESS_H

#include <linux/errno.h>
#include <linux/sched.h>

#define STR(x)  __STR(x)
#define __STR(x)  #x

/*
 * 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 KERNEL_DS	((mm_segment_t) { (unsigned long) 0L })
#define USER_DS		((mm_segment_t) { (unsigned long) -1L })

#define VERIFY_READ    0
#define VERIFY_WRITE   1

#define get_fs()        (current->thread.current_ds)
#define get_ds()	(KERNEL_DS)
#define set_fs(x)       (current->thread.current_ds=(x))

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


/*
 * Is a address valid? This does a straighforward calculation rather
 * than tests.
 *
 * Address valid if:
 *  - "addr" doesn't have any high-bits set
 *  - AND "size" doesn't have any high-bits set
 *  - AND "addr+size" doesn't have any high-bits set
 *  - OR we are in kernel mode.
 */
#define __ua_size(size)							\
	(__builtin_constant_p(size) && (signed long) (size) > 0 ? 0 : (size))

#define __access_ok(addr,size,mask)					\
	(((signed long)((mask)&(addr | (addr + size) | __ua_size(size)))) >= 0)

#define __access_mask ((long)(get_fs().seg))

#define access_ok(type,addr,size) \
	__access_ok(((unsigned long)(addr)),(size),__access_mask)

static inline int verify_area(int type, const void * addr, unsigned long size)
{
	return access_ok(type,addr,size) ? 0 : -EFAULT;
}

/*
 * Uh, these should become the main single-value transfer routines ...
 * They automatically use the right size if we just have the right
 * pointer type ...
 *
 * As MIPS uses the same address space for kernel and user data, we
 * can just do these as direct assignments.
 *
 * Careful to not
 * (a) re-use the arguments for side effects (sizeof is ok)
 * (b) require any knowledge of processes at this stage
 */
#define put_user(x,ptr)	\
	__put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
#define get_user(x,ptr) \
	__get_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))

/*
 * The "__xxx" versions do not do address space checking, useful when
 * doing multiple accesses to the same area (the user has to do the
 * checks by hand with "access_ok()")
 */
#define __put_user(x,ptr) \
	__put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
#define __get_user(x,ptr) \
	__get_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))

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

#define __get_user_nocheck(x,ptr,size)				\
({								\
	long __gu_err;						\
	__typeof(*(ptr)) __gu_val;				\
	long __gu_addr;						\
	__asm__("":"=r" (__gu_val));				\
	__gu_addr = (long) (ptr);				\
	__asm__("":"=r" (__gu_err));				\
	switch (size) {						\
	case 1: __get_user_asm("lb"); break;			\
	case 2: __get_user_asm("lh"); break;			\
	case 4: __get_user_asm("lw"); break;			\
	case 8: __get_user_asm("ld"); break;			\
	default: __get_user_unknown(); break;			\
	} x = (__typeof__(*(ptr))) __gu_val; __gu_err;		\
})

#define __get_user_check(x,ptr,size)				\
({								\
	long __gu_err;						\
	__typeof__(*(ptr)) __gu_val;				\
	long __gu_addr;						\
	__asm__("":"=r" (__gu_val));				\
	__gu_addr = (long) (ptr);				\
	__asm__("":"=r" (__gu_err));				\
	if (__access_ok(__gu_addr,size,__access_mask)) {	\
		switch (size) {					\
		case 1: __get_user_asm("lb"); break;		\
		case 2: __get_user_asm("lh"); break;		\
		case 4: __get_user_asm("lw"); break;		\
		case 8: __get_user_asm("ld"); break;		\
		default: __get_user_unknown(); break;		\
		}						\
	} x = (__typeof__(*(ptr))) __gu_val; __gu_err;		\
})

#define __get_user_asm(insn)					\
({								\
	__asm__ __volatile__(					\
	"1:\t" insn "\t%1,%2\n\t"				\
	"move\t%0,$0\n"						\
	"2:\n\t"						\
	".section\t.fixup,\"ax\"\n"				\
	"3:\tli\t%0,%3\n\t"					\
	"move\t%1,$0\n\t"					\
	"j\t2b\n\t"						\
	".previous\n\t"						\
	".section\t__ex_table,\"a\"\n\t"			\
	".dword\t1b,3b\n\t"					\
	".previous"						\
	:"=r" (__gu_err), "=r" (__gu_val)			\
	:"o" (__m(__gu_addr)), "i" (-EFAULT));			\
})

extern void __get_user_unknown(void);

#define __put_user_nocheck(x,ptr,size)				\
({								\
	long __pu_err;						\
	__typeof__(*(ptr)) __pu_val;				\
	long __pu_addr;						\
	__pu_val = (x);						\
	__pu_addr = (long) (ptr);				\
	__asm__("":"=r" (__pu_err));				\
	switch (size) {						\
	case 1: __put_user_asm("sb"); break;			\
	case 2: __put_user_asm("sh"); break;			\
	case 4: __put_user_asm("sw"); break;			\
	case 8: __put_user_asm("sd"); break;			\
	default: __put_user_unknown(); break;			\
	} __pu_err;						\
})

#define __put_user_check(x,ptr,size)				\
({								\
	long __pu_err;						\
	__typeof__(*(ptr)) __pu_val;				\
	long __pu_addr;						\
	__pu_val = (x);						\
	__pu_addr = (long) (ptr);				\
	__asm__("":"=r" (__pu_err));				\
	if (__access_ok(__pu_addr,size,__access_mask)) { 	\
		switch (size) {					\
		case 1: __put_user_asm("sb"); break;		\
		case 2: __put_user_asm("sh"); break;		\
		case 4: __put_user_asm("sw"); break;		\
		case 8: __put_user_asm("sd"); break;		\
		default: __put_user_unknown(); break;		\
		}						\
	} __pu_err;						\
})

#define __put_user_asm(insn)					\
({								\
	__asm__ __volatile__(					\
	"1:\t" insn "\t%z1, %2\t\t\t# __put_user_asm\n\t"	\
	"move\t%0,$0\n"						\
	"2:\n\t"						\
	".section\t.fixup,\"ax\"\n"				\
	"3:\tli\t%0,%3\n\t"					\
	"j\t2b\n\t"						\
	".previous\n\t"						\
	".section\t__ex_table,\"a\"\n\t"			\
	".dword\t1b,3b\n\t"					\
	".previous"						\
	:"=r" (__pu_err)					\
	:"Jr" (__pu_val), "o" (__m(__pu_addr)), "i" (-EFAULT));	\
})

extern void __put_user_unknown(void);

/*
 * We're generating jump to subroutines which will be outside the range of
 * jump instructions
 */
#ifdef MODULE
#define __MODULE_JAL(destination)	\
	".set\tnoat\n\t"		\
	"dla\t$1, " #destination "\n\t" \
	"jalr\t$1\n\t"			\
	".set\tat\n\t"
#else
#define __MODULE_JAL(destination)	\
	"jal\t" #destination "\n\t"
#endif

extern size_t __copy_user(void *__to, const void *__from, size_t __n);

#define __invoke_copy_to_user(to,from,n)				\
({									\
	register void *__cu_to_r __asm__ ("$4");			\
	register const void *__cu_from_r __asm__ ("$5");		\
	register long __cu_len_r __asm__ ("$6");			\
									\
	__cu_to_r = (to);						\
	__cu_from_r = (from);						\
	__cu_len_r = (n);						\
	__asm__ __volatile__(						\
	__MODULE_JAL(__copy_user)					\
	: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)	\
	:								\
	: "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31",		\
	  "memory");							\
	__cu_len_r;							\
})

#define __copy_to_user(to,from,n)					\
({									\
	void *__cu_to;							\
	const void *__cu_from;						\
	long __cu_len;							\
									\
	__cu_to = (to);							\
	__cu_from = (from);						\
	__cu_len = (n);							\
	__cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len);	\
	__cu_len;							\
})

#define copy_to_user(to,from,n)						\
({									\
	void *__cu_to;							\
	const void *__cu_from;						\
	long __cu_len;							\
									\
	__cu_to = (to);							\
	__cu_from = (from);						\
	__cu_len = (n);							\
	if (access_ok(VERIFY_WRITE, __cu_to, __cu_len))			\
		__cu_len = __invoke_copy_to_user(__cu_to, __cu_from,	\
		                                __cu_len);		\
	__cu_len;							\
})

#define __invoke_copy_from_user(to,from,n)				\
({									\
	register void *__cu_to_r __asm__ ("$4");			\
	register const void *__cu_from_r __asm__ ("$5");		\
	register long __cu_len_r __asm__ ("$6");			\
									\
	__cu_to_r = (to);						\
	__cu_from_r = (from);						\
	__cu_len_r = (n);						\
	__asm__ __volatile__(						\
	".set\tnoreorder\n\t"						\
	__MODULE_JAL(__copy_user)					\
	".set\tnoat\n\t"						\
	"daddu\t$1, %1, %2\n\t"						\
	".set\tat\n\t"							\
	".set\treorder\n\t"						\
	"move\t%0, $6"							\
	: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)	\
	:								\
	: "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31",		\
	  "memory");							\
	__cu_len_r;							\
})

#define __copy_from_user(to,from,n)					\
({									\
	void *__cu_to;							\
	const void *__cu_from;						\
	long __cu_len;							\
									\
	__cu_to = (to);							\
	__cu_from = (from);						\
	__cu_len = (n);							\
	__cu_len = __invoke_copy_from_user(__cu_to, __cu_from,		\
	                                   __cu_len);			\
	__cu_len;							\
})

#define copy_from_user(to,from,n)					\
({									\
	void *__cu_to;							\
	const void *__cu_from;						\
	long __cu_len;							\
									\
	__cu_to = (to);							\
	__cu_from = (from);						\
	__cu_len = (n);							\
	if (access_ok(VERIFY_READ, __cu_from, __cu_len))		\
		__cu_len = __invoke_copy_from_user(__cu_to, __cu_from,	\
		                                   __cu_len);		\
	__cu_len;							\
})

static inline __kernel_size_t
__clear_user(void *addr, __kernel_size_t size)
{
	__kernel_size_t res;

	__asm__ __volatile__(
		"move\t$4, %1\n\t"
		"move\t$5, $0\n\t"
		"move\t$6, %2\n\t"
		__MODULE_JAL(__bzero)
		"move\t%0, $6"
		: "=r" (res)
		: "r" (addr), "r" (size)
		: "$4", "$5", "$6", "$8", "$9", "$31");

	return res;
}

#define clear_user(addr,n)					\
({								\
	void * __cl_addr = (addr);				\
	unsigned long __cl_size = (n);				\
	if (__cl_size && __access_ok(VERIFY_WRITE,		\
	       ((unsigned long)(__cl_addr)), __cl_size))	\
		__cl_size = __clear_user(__cl_addr, __cl_size);	\
	__cl_size;						\
})

/*
 * Returns: -EFAULT if exception before terminator, N if the entire
 * buffer filled, else strlen.
 */
static inline long
__strncpy_from_user(char *__to, const char *__from, long __len)
{
	long res;

	__asm__ __volatile__(
		"move\t$4, %1\n\t"
		"move\t$5, %2\n\t"
		"move\t$6, %3\n\t"
		__MODULE_JAL(__strncpy_from_user_nocheck_asm)
		"move\t%0, $2"
		: "=r" (res)
		: "r" (__to), "r" (__from), "r" (__len)
		: "$2", "$3", "$4", "$5", "$6", "$8", "$31", "memory");

	return res;
}

static inline long
strncpy_from_user(char *__to, const char *__from, long __len)
{
	long res;

	__asm__ __volatile__(
		"move\t$4, %1\n\t"
		"move\t$5, %2\n\t"
		"move\t$6, %3\n\t"
		__MODULE_JAL(__strncpy_from_user_asm)
		"move\t%0, $2"
		: "=r" (res)
		: "r" (__to), "r" (__from), "r" (__len)
		: "$2", "$3", "$4", "$5", "$6", "$8", "$31", "memory");

	return res;
}

/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
static inline long __strlen_user(const char *s)
{
	long res;

	__asm__ __volatile__(
		"move\t$4, %1\n\t"
		__MODULE_JAL(__strlen_user_nocheck_asm)
		"move\t%0, $2"
		: "=r" (res)
		: "r" (s)
		: "$2", "$4", "$8", "$31");

	return res;
}

static inline long strlen_user(const char *s)
{
	long res;

	__asm__ __volatile__(
		"move\t$4, %1\n\t"
		__MODULE_JAL(__strlen_user_asm)
		"move\t%0, $2"
		: "=r" (res)
		: "r" (s)
		: "$2", "$4", "$8", "$31");

	return res;
}

/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
static inline long __strnlen_user(const char *s, long n)
{
	long res;

	__asm__ __volatile__(
		"move\t$4, %1\n\t"
		"move\t$5, %2\n\t"
		__MODULE_JAL(__strlen_user_nocheck_asm)
		"move\t%0, $2"
		: "=r" (res)
		: "r" (s), "r" (n)
		: "$2", "$4", "$5", "$8", "$31");

	return res;
}

static inline long strnlen_user(const char *s, long n)
{
	long res;

	__asm__ __volatile__(
		"move\t$4, %1\n\t"
		"move\t$5, %2\n\t"
		__MODULE_JAL(__strlen_user_asm)
		"move\t%0, $2"
		: "=r" (res)
		: "r" (s), "r" (n)
		: "$2", "$4", "$5", "$8", "$31");

	return res;
}

struct exception_table_entry
{
	unsigned long insn;
	unsigned long nextinsn;
};

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

/* Returns the new pc */
#define fixup_exception(map_reg, fixup_unit, pc)                \
({                                                              \
	fixup_unit;                                             \
})

#endif /* _ASM_UACCESS_H */