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   1 /*
   2  * Copyright (C) 2006 Atmark Techno, Inc.
   3  *
   4  * This file is subject to the terms and conditions of the GNU General Public
   5  * License. See the file "COPYING" in the main directory of this archive
   6  * for more details.
   7  */
   8
   9 #ifndef _ASM_MICROBLAZE_UACCESS_H
  10 #define _ASM_MICROBLAZE_UACCESS_H
  11
  12 #ifdef __KERNEL__
  13 #ifndef __ASSEMBLY__
  14
  15 #include <linux/kernel.h>
  16 #include <linux/errno.h>
  17 #include <linux/sched.h> /* RLIMIT_FSIZE */
  18 #include <linux/mm.h>
  19
  20 #include <asm/mmu.h>
  21 #include <asm/page.h>
  22 #include <asm/pgtable.h>
  23 #include <asm/segment.h>
  24 #include <linux/string.h>
  25
  26 #define VERIFY_READ     0
  27 #define VERIFY_WRITE    1
  28
  29 extern int ___range_ok(unsigned long addr, unsigned long size);
  30
  31 #define __range_ok(addr, size) \
  32                 ___range_ok((unsigned long)(addr), (unsigned long)(size))
  33
  34 #define access_ok(type, addr, size) (__range_ok((addr), (size)) == 0)
  35 #define __access_ok(add, size) (__range_ok((addr), (size)) == 0)
  36
  37 extern inline int bad_user_access_length(void)
  38 {
  39         return 0;
  40 }
  41 /* FIXME this is function for optimalization -> memcpy */
  42 #define __get_user(var, ptr)                                    \
  43         ({                                                      \
  44                 int __gu_err = 0;                               \
  45                 switch (sizeof(*(ptr))) {                       \
  46                 case 1:                                         \
  47                 case 2:                                         \
  48                 case 4:                                         \
  49                         (var) = *(ptr);                         \
  50                         break;                                  \
  51                 case 8:                                         \
  52                         memcpy((void *) &(var), (ptr), 8);      \
  53                         break;                                  \
  54                 default:                                        \
  55                         (var) = 0;                              \
  56                         __gu_err = __get_user_bad();            \
  57                         break;                                  \
  58                 }                                               \
  59                 __gu_err;                                       \
  60         })
  61
  62 #define __get_user_bad()        (bad_user_access_length(), (-EFAULT))
  63
  64 #define __put_user(var, ptr)                                    \
  65         ({                                                      \
  66                 int __pu_err = 0;                               \
  67                 switch (sizeof(*(ptr))) {                       \
  68                 case 1:                                         \
  69                 case 2:                                         \
  70                 case 4:                                         \
  71                         *(ptr) = (var);                         \
  72                         break;                                  \
  73                 case 8: {                                       \
  74                         typeof(*(ptr)) __pu_val = var;          \
  75                         memcpy(ptr, &__pu_val, sizeof(__pu_val));\
  76                         }                                       \
  77                         break;                                  \
  78                 default:                                        \
  79                         __pu_err = __put_user_bad();            \
  80                         break;                                  \
  81                 }                                                       \
  82                 __pu_err;                                               \
  83         })
  84
  85 #define __put_user_bad()        (bad_user_access_length(), (-EFAULT))
  86
  87 #define put_user(x, ptr)        __put_user(x, ptr)
  88 #define get_user(x, ptr)        __get_user(x, ptr)
  89
  90 #define copy_to_user(to, from, n)               (memcpy(to, from, n), 0)
  91 #define copy_from_user(to, from, n)             (memcpy(to, from, n), 0)
  92
  93 #define __copy_to_user(to, from, n)             (copy_to_user(to, from, n))
  94 #define __copy_from_user(to, from, n)           (copy_from_user(to, from, n))
  95 #define __copy_to_user_inatomic(to, from, n)    (__copy_to_user(to, from, n))
  96 #define __copy_from_user_inatomic(to, from, n)  (__copy_from_user(to, from, n))
  97
  98 #define __clear_user(addr, n)   (memset((void *)addr, 0, n), 0)
  99
 100 static inline unsigned long clear_user(void *addr, unsigned long size)
 101 {
 102         if (access_ok(VERIFY_WRITE, addr, size))
 103                 size = __clear_user(addr, size);
 104         return size;
 105 }
 106
 107 /* Returns 0 if exception not found and fixup otherwise. */
 108 extern unsigned long search_exception_table(unsigned long);
 109
 110
 111 extern long strncpy_from_user(char *dst, const char __user *src, long count);
 112 extern long strnlen_user(const char __user *src, long count);
 113 extern long __strncpy_from_user(char *dst, const char __user *src, long count);
 114
 115 /*
 116  * The exception table consists of pairs of addresses: the first is the
 117  * address of an instruction that is allowed to fault, and the second is
 118  * the address at which the program should continue. No registers are
 119  * modified, so it is entirely up to the continuation code to figure out
 120  * what to do.
 121  *
 122  * All the routines below use bits of fixup code that are out of line
 123  * with the main instruction path. This means when everything is well,
 124  * we don't even have to jump over them. Further, they do not intrude
 125  * on our cache or tlb entries.
 126  */
 127 struct exception_table_entry {
 128         unsigned long insn, fixup;
 129 };
 130
 131 #endif  /* __ASSEMBLY__ */
 132 #endif /* __KERNEL__ */
 133
 134 #endif /* _ASM_MICROBLAZE_UACCESS_H */