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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 static 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 /*
  31  * The exception table consists of pairs of addresses: the first is the
  32  * address of an instruction that is allowed to fault, and the second is
  33  * the address at which the program should continue.  No registers are
  34  * modified, so it is entirely up to the continuation code to figure out
  35  * what to do.
  36  *
  37  * All the routines below use bits of fixup code that are out of line
  38  * with the main instruction path.  This means when everything is well,
  39  * we don't even have to jump over them.  Further, they do not intrude
  40  * on our cache or tlb entries.
  41  */
  42
  43 struct exception_table_entry
  44 {
  45         unsigned long insn, fixup;
  46 };
  47
  48 /* Returns 0 if exception not found and fixup otherwise.  */
  49 extern unsigned long search_exception_table (unsigned long);
  50
  51
  52 /*
  53  * These are the main single-value transfer routines.  They automatically
  54  * use the right size if we just have the right pointer type.
  55  */
  56
  57 extern int bad_user_access_length (void);
  58
  59 #define __get_user(var, ptr)                                                  \
  60   ({                                                                          \
  61           int __gu_err = 0;                                                   \
  62           typeof(*(ptr)) __gu_val = 0;                                        \
  63           switch (sizeof (*(ptr))) {                                          \
  64           case 1:                                                             \
  65           case 2:                                                             \
  66           case 4:                                                             \
  67                   __gu_val = *(ptr);                                          \
  68                   break;                                                      \
  69           case 8:                                                             \
  70                   memcpy(&__gu_val, ptr, sizeof(__gu_val));                   \
  71                   break;                                                      \
  72           default:                                                            \
  73                   __gu_val = 0;                                               \
  74                   __gu_err = __get_user_bad ();                               \
  75                   break;                                                      \
  76           }                                                                   \
  77           (var) = __gu_val;                                                   \
  78           __gu_err;                                                           \
  79   })
  80 #define __get_user_bad()        (bad_user_access_length (), (-EFAULT))
  81
  82 #define __put_user(var, ptr)                                                  \
  83   ({                                                                          \
  84           int __pu_err = 0;                                                   \
  85           switch (sizeof (*(ptr))) {                                          \
  86           case 1:                                                             \
  87           case 2:                                                             \
  88           case 4:                                                             \
  89                   *(ptr) = (var);                                             \
  90                   break;                                                      \
  91           case 8: {                                                           \
  92                   typeof(*(ptr)) __pu_val = 0;                                \
  93                   memcpy(ptr, &__pu_val, sizeof(__pu_val));                   \
  94                   }                                                           \
  95                   break;                                                      \
  96           default:                                                            \
  97                   __pu_err = __put_user_bad ();                               \
  98                   break;                                                      \
  99           }                                                                   \
 100           __pu_err;                                                           \
 101   })
 102 #define __put_user_bad()        (bad_user_access_length (), (-EFAULT))
 103
 104 #define put_user(x, ptr)        __put_user(x, ptr)
 105 #define get_user(x, ptr)        __get_user(x, ptr)
 106
 107 #define __copy_from_user(to, from, n)   (memcpy (to, from, n), 0)
 108 #define __copy_to_user(to, from, n)     (memcpy(to, from, n), 0)
 109
 110 #define __copy_to_user_inatomic __copy_to_user
 111 #define __copy_from_user_inatomic __copy_from_user
 112
 113 #define copy_from_user(to, from, n)     __copy_from_user (to, from, n)
 114 #define copy_to_user(to, from, n)       __copy_to_user(to, from, n)
 115
 116 #define copy_to_user_ret(to,from,n,retval) \
 117   ({ if (copy_to_user (to,from,n)) return retval; })
 118
 119 #define copy_from_user_ret(to,from,n,retval) \
 120   ({ if (copy_from_user (to,from,n)) return retval; })
 121
 122 /*
 123  * Copy a null terminated string from userspace.
 124  */
 125
 126 static inline long
 127 strncpy_from_user (char *dst, const char *src, long count)
 128 {
 129         char *tmp;
 130         strncpy (dst, src, count);
 131         for (tmp = dst; *tmp && count > 0; tmp++, count--)
 132                 ;
 133         return tmp - dst;
 134 }
 135
 136 /*
 137  * Return the size of a string (including the ending 0)
 138  *
 139  * Return 0 on exception, a value greater than N if too long
 140  */
 141 static inline long strnlen_user (const char *src, long n)
 142 {
 143         return strlen (src) + 1;
 144 }
 145
 146 #define strlen_user(str)        strnlen_user (str, 32767)
 147
 148 /*
 149  * Zero Userspace
 150  */
 151
 152 static inline unsigned long
 153 clear_user (void *to, unsigned long n)
 154 {
 155         memset (to, 0, n);
 156         return 0;
 157 }
 158
 159 #endif /* __V850_UACCESS_H__ */