#ifndef __i386_UACCESS_H
#define __i386_UACCESS_H

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


#define KERNEL_DS       MAKE_MM_SEG(0xFFFFFFFF)
#define USER_DS         MAKE_MM_SEG(PAGE_OFFSET)

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

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

/*
 * movsl can be slow when source and dest are not both 8-byte aligned
 */
#ifdef CONFIG_X86_INTEL_USERCOPY
extern struct movsl_mask {
        int mask;
} ____cacheline_aligned_in_smp movsl_mask;
#endif

int __verify_write(const void *, unsigned long);

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

/*
 * Uhhuh, this needs 33-bit arithmetic. We have a carry..
 */
#define __range_ok(addr,size) ({ \
        unsigned long flag,sum; \
        asm("addl %3,%1 ; sbbl %0,%0; cmpl %1,%4; sbbl $0,%0" \
                :"=&r" (flag), "=r" (sum) \
                :"1" (addr),"g" ((int)(size)),"g" (current_thread_info()->addr_limit.seg)); \
        flag; })

#ifdef CONFIG_X86_WP_WORKS_OK

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

#else

#define access_ok(type,addr,size) ( (__range_ok(addr,size) == 0) && \
                         ((type) == VERIFY_READ || boot_cpu_data.wp_works_ok || \
                          __verify_write((void *)(addr),(size))))

#endif

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


/*
 * 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;
};

/*
 * 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);

#define __get_user_x(size,ret,x,ptr) \
        __asm__ __volatile__("call __get_user_" #size \
                :"=a" (ret),"=d" (x) \
                :"0" (ptr))

/* Careful: we have to cast the result to the type of the pointer for sign reasons */
#define get_user(x,ptr)                                                 \
({      int __ret_gu,__val_gu;                                          \
        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_1(void);
extern void __put_user_2(void);
extern void __put_user_4(void);
extern void __put_user_8(void);

extern void __put_user_bad(void);

#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)))

#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_u64(x, addr, err)                            \
        __asm__ __volatile__(                                   \
                "1:     movl %%eax,0(%2)\n"                     \
                "2:     movl %%edx,4(%2)\n"                     \
                "3:\n"                                          \
                ".section .fixup,\"ax\"\n"                      \
                "4:     movl %3,%0\n"                           \
                "       jmp 3b\n"                               \
                ".previous\n"                                   \
                ".section __ex_table,\"a\"\n"                   \
                "       .align 4\n"                             \
                "       .long 1b,4b\n"                          \
                "       .long 2b,4b\n"                          \
                ".previous"                                     \
                : "=r"(err)                                     \
                : "A" (x), "r" (addr), "i"(-EFAULT), "0"(err))

#define __put_user_size(x,ptr,size,retval)                              \
do {                                                                    \
        retval = 0;                                                     \
        switch (size) {                                                 \
          case 1: __put_user_asm(x,ptr,retval,"b","b","iq"); break;     \
          case 2: __put_user_asm(x,ptr,retval,"w","w","ir"); break;     \
          case 4: __put_user_asm(x,ptr,retval,"l","","ir"); 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, rtype, ltype)       \
        __asm__ __volatile__(                                   \
                "1:     mov"itype" %"rtype"1,%2\n"              \
                "2:\n"                                          \
                ".section .fixup,\"ax\"\n"                      \
                "3:     movl %3,%0\n"                           \
                "       jmp 2b\n"                               \
                ".previous\n"                                   \
                ".section __ex_table,\"a\"\n"                   \
                "       .align 4\n"                             \
                "       .long 1b,3b\n"                          \
                ".previous"                                     \
                : "=r"(err)                                     \
                : ltype (x), "m"(__m(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) = (__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,"b","b","=q"); break;     \
          case 2: __get_user_asm(x,ptr,retval,"w","w","=r"); break;     \
          case 4: __get_user_asm(x,ptr,retval,"l","","=r"); break;      \
          default: (x) = __get_user_bad();                              \
        }                                                               \
} while (0)

#define __get_user_asm(x, addr, err, itype, rtype, ltype)       \
        __asm__ __volatile__(                                   \
                "1:     mov"itype" %2,%"rtype"1\n"              \
                "2:\n"                                          \
                ".section .fixup,\"ax\"\n"                      \
                "3:     movl %3,%0\n"                           \
                "       xor"itype" %"rtype"1,%"rtype"1\n"       \
                "       jmp 2b\n"                               \
                ".previous\n"                                   \
                ".section __ex_table,\"a\"\n"                   \
                "       .align 4\n"                             \
                "       .long 1b,3b\n"                          \
                ".previous"                                     \
                : "=r"(err), ltype (x)                          \
                : "m"(__m(addr)), "i"(-EFAULT), "0"(err))


unsigned long copy_to_user(void *to, const void *from, unsigned long n);
unsigned long copy_from_user(void *to, const void *from, unsigned long n);
unsigned long __copy_to_user(void *to, const void *from, unsigned long n);
unsigned long __copy_from_user(void *to, const void *from, unsigned long n);

long strncpy_from_user(char *dst, const char *src, long count);
long __strncpy_from_user(char *dst, const char *src, long count);
#define strlen_user(str) strnlen_user(str, ~0UL >> 1)
long strnlen_user(const char *str, long n);
unsigned long clear_user(void *mem, unsigned long len);
unsigned long __clear_user(void *mem, unsigned long len);

#endif /* __i386_UACCESS_H */