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   1 #ifndef __V850_UACCESS_H__
   2 #define __V850_UACCESS_H__
   3
   4 /*
   5  * User space memory access functions
   6  */
   7
   8 #include <linux/errno.h>
   9 #include <linux/string.h>
  10
  11 #include <asm/segment.h>
  12 #include <asm/machdep.h>
  13
  14 #define VERIFY_READ     0
  15 #define VERIFY_WRITE    1
  16
  17 extern inline int access_ok (int type, const void *addr, unsigned long size)
  18 {
  19         /* XXX I guess we should check against real ram bounds at least, and
  20            possibly make sure ADDR is not within the kernel.
  21            For now we just check to make sure it's not a small positive
  22            or negative value, as that will at least catch some kinds of
  23            error.  In particular, we make sure that ADDR's not within the
  24            interrupt vector area, which we know starts at zero, or within the
  25            peripheral-I/O area, which is located just _before_ zero.  */
  26         unsigned long val = (unsigned long)addr;
  27         return val >= (0x80 + NUM_CPU_IRQS*16) && val < 0xFFFFF000;
  28 }
  29
  30 /* this function will go away soon - use access_ok() instead */
  31 extern inline int __deprecated verify_area (int type, const void *addr, unsigned long size)
  32 {
  33         return access_ok (type, addr, size) ? 0 : -EFAULT;
  34 }
  35
  36 /*
  37  * The exception table consists of pairs of addresses: the first is the
  38  * address of an instruction that is allowed to fault, and the second is
  39  * the address at which the program should continue.  No registers are
  40  * modified, so it is entirely up to the continuation code to figure out
  41  * what to do.
  42  *
  43  * All the routines below use bits of fixup code that are out of line
  44  * with the main instruction path.  This means when everything is well,
  45  * we don't even have to jump over them.  Further, they do not intrude
  46  * on our cache or tlb entries.
  47  */
  48
  49 struct exception_table_entry
  50 {
  51         unsigned long insn, fixup;
  52 };
  53
  54 /* Returns 0 if exception not found and fixup otherwise.  */
  55 extern unsigned long search_exception_table (unsigned long);
  56
  57
  58 /*
  59  * These are the main single-value transfer routines.  They automatically
  60  * use the right size if we just have the right pointer type.
  61  */
  62
  63 extern int bad_user_access_length (void);
  64
  65 #define __get_user(var, ptr)                                                  \
  66   ({                                                                          \
  67           int __gu_err = 0;                                                   \
  68           typeof(*(ptr)) __gu_val = 0;                                        \
  69           switch (sizeof (*(ptr))) {                                          \
  70           case 1:                                                             \
  71           case 2:                                                             \
  72           case 4:                                                             \
  73                   __gu_val = *(ptr);                                          \
  74                   break;                                                      \
  75           case 8:                                                             \
  76                   memcpy(&__gu_val, ptr, sizeof(__gu_val));                   \
  77                   break;                                                      \
  78           default:                                                            \
  79                   __gu_val = 0;                                               \
  80                   __gu_err = __get_user_bad ();                               \
  81                   break;                                                      \
  82           }                                                                   \
  83           (var) = __gu_val;                                                   \
  84           __gu_err;                                                           \
  85   })
  86 #define __get_user_bad()        (bad_user_access_length (), (-EFAULT))
  87
  88 #define __put_user(var, ptr)                                                  \
  89   ({                                                                          \
  90           int __pu_err = 0;                                                   \
  91           switch (sizeof (*(ptr))) {                                          \
  92           case 1:                                                             \
  93           case 2:                                                             \
  94           case 4:                                                             \
  95                   *(ptr) = (var);                                             \
  96                   break;                                                      \
  97           case 8: {                                                           \
  98                   typeof(*(ptr)) __pu_val = 0;                                \
  99                   memcpy(ptr, &__pu_val, sizeof(__pu_val));                   \
 100                   }                                                           \
 101                   break;                                                      \
 102           default:                                                            \
 103                   __pu_err = __put_user_bad ();                               \
 104                   break;                                                      \
 105           }                                                                   \
 106           __pu_err;                                                           \
 107   })
 108 #define __put_user_bad()        (bad_user_access_length (), (-EFAULT))
 109
 110 #define put_user(x, ptr)        __put_user(x, ptr)
 111 #define get_user(x, ptr)        __get_user(x, ptr)
 112
 113 #define __copy_from_user(to, from, n)   (memcpy (to, from, n), 0)
 114 #define __copy_to_user(to, from, n)     (memcpy(to, from, n), 0)
 115
 116 #define __copy_to_user_inatomic __copy_to_user
 117 #define __copy_from_user_inatomic __copy_from_user
 118
 119 #define copy_from_user(to, from, n)     __copy_from_user (to, from, n)
 120 #define copy_to_user(to, from, n)       __copy_to_user(to, from, n)
 121
 122 #define copy_to_user_ret(to,from,n,retval) \
 123   ({ if (copy_to_user (to,from,n)) return retval; })
 124
 125 #define copy_from_user_ret(to,from,n,retval) \
 126   ({ if (copy_from_user (to,from,n)) return retval; })
 127
 128 /*
 129  * Copy a null terminated string from userspace.
 130  */
 131
 132 static inline long
 133 strncpy_from_user (char *dst, const char *src, long count)
 134 {
 135         char *tmp;
 136         strncpy (dst, src, count);
 137         for (tmp = dst; *tmp && count > 0; tmp++, count--)
 138                 ;
 139         return tmp - dst;
 140 }
 141
 142 /*
 143  * Return the size of a string (including the ending 0)
 144  *
 145  * Return 0 on exception, a value greater than N if too long
 146  */
 147 static inline long strnlen_user (const char *src, long n)
 148 {
 149         return strlen (src) + 1;
 150 }
 151
 152 #define strlen_user(str)        strnlen_user (str, 32767)
 153
 154 /*
 155  * Zero Userspace
 156  */
 157
 158 static inline unsigned long
 159 clear_user (void *to, unsigned long n)
 160 {
 161         memset (to, 0, n);
 162         return 0;
 163 }
 164
 165 #endif /* __V850_UACCESS_H__ */