include/asm-h8300/uaccess.h

   1 #ifndef __H8300_UACCESS_H
   2 #define __H8300_UACCESS_H
   3
   4 /*
   5  * User space memory access functions
   6  */
   7 #include <linux/sched.h>
   8 #include <linux/mm.h>
   9 #include <linux/string.h>
  10
  11 #include <asm/segment.h>
  12
  13 #define VERIFY_READ     0
  14 #define VERIFY_WRITE    1
  15
  16 /* We let the MMU do all checking */
  17 extern inline int access_ok(int type, const void * addr, unsigned long size)
  18 {
  19 #define RANGE_CHECK_OK(addr, size, lower, upper) \
  20         (((addr) >= (lower)) && (((addr) + (size)) < (upper)))
  21
  22         extern unsigned long _ramend;
  23         return(RANGE_CHECK_OK((unsigned long) addr, size, 0L, (unsigned long)&_ramend));
  24 }
  25
  26 extern inline int verify_area(int type, const void * addr, unsigned long size)
  27 {
  28         return access_ok(type,addr,size)?0:-EFAULT;
  29 }
  30
  31 /*
  32  * The exception table consists of pairs of addresses: the first is the
  33  * address of an instruction that is allowed to fault, and the second is
  34  * the address at which the program should continue.  No registers are
  35  * modified, so it is entirely up to the continuation code to figure out
  36  * what to do.
  37  *
  38  * All the routines below use bits of fixup code that are out of line
  39  * with the main instruction path.  This means when everything is well,
  40  * we don't even have to jump over them.  Further, they do not intrude
  41  * on our cache or tlb entries.
  42  */
  43
  44 struct exception_table_entry
  45 {
  46         unsigned long insn, fixup;
  47 };
  48
  49 /* Returns 0 if exception not found and fixup otherwise.  */
  50 extern unsigned long search_exception_table(unsigned long);
  51
  52
  53 /*
  54  * These are the main single-value transfer routines.  They automatically
  55  * use the right size if we just have the right pointer type.
  56  */
  57
  58 #define put_user(x, ptr)                                \
  59 ({                                                      \
  60     int __pu_err = 0;                                   \
  61     typeof(*(ptr)) __pu_val = (x);                      \
  62     switch (sizeof (*(ptr))) {                          \
  63     case 1:                                             \
  64     case 2:                                             \
  65     case 4:                                             \
  66         *(ptr) = (__pu_val);                            \
  67         break;                                          \
  68     case 8:                                             \
  69         memcpy(ptr, &__pu_val, sizeof (*(ptr)));        \
  70         break;                                          \
  71     default:                                            \
  72         __pu_err = __put_user_bad();                    \
  73         break;                                          \
  74     }                                                   \
  75     __pu_err;                                           \
  76 })
  77 #define __put_user(x, ptr) put_user(x, ptr)
  78
  79 extern int __put_user_bad(void);
  80
  81 /*
  82  * Tell gcc we read from memory instead of writing: this is because
  83  * we do not write to any memory gcc knows about, so there are no
  84  * aliasing issues.
  85  */
  86
  87 #define __ptr(x) ((unsigned long *)(x))
  88
  89 /*
  90  * Tell gcc we read from memory instead of writing: this is because
  91  * we do not write to any memory gcc knows about, so there are no
  92  * aliasing issues.
  93  */
  94
  95 #define get_user(x, ptr)                                        \
  96 ({                                                              \
  97     int __gu_err = 0;                                           \
  98     typeof(*(ptr)) __gu_val = 0;                                \
  99     switch (sizeof(*(ptr))) {                                   \
 100     case 1:                                                     \
 101     case 2:                                                     \
 102     case 4:                                                     \
 103         __gu_val = *(ptr);                                      \
 104         break;                                                  \
 105     case 8:                                                     \
 106         memcpy(&__gu_val, ptr, sizeof (*(ptr)));                \
 107         break;                                                  \
 108     default:                                                    \
 109         __gu_val = 0;                                           \
 110         __gu_err = __get_user_bad();                            \
 111         break;                                                  \
 112     }                                                           \
 113     (x) = __gu_val;                                             \
 114     __gu_err;                                                   \
 115 })
 116 #define __get_user(x, ptr) get_user(x, ptr)
 117
 118 extern int __get_user_bad(void);
 119
 120 #define copy_from_user(to, from, n)             (memcpy(to, from, n), 0)
 121 #define copy_to_user(to, from, n)               (memcpy(to, from, n), 0)
 122
 123 #define __copy_from_user(to, from, n) copy_from_user(to, from, n)
 124 #define __copy_to_user(to, from, n) copy_to_user(to, from, n)
 125
 126 #define copy_to_user_ret(to,from,n,retval) ({ if (copy_to_user(to,from,n)) return retval; })
 127
 128 #define copy_from_user_ret(to,from,n,retval) ({ if (copy_from_user(to,from,n)) return retval; })
 129
 130 /*
 131  * Copy a null terminated string from userspace.
 132  */
 133
 134 static inline long
 135 strncpy_from_user(char *dst, const char *src, long count)
 136 {
 137         char *tmp;
 138         strncpy(dst, src, count);
 139         for (tmp = dst; *tmp && count > 0; tmp++, count--)
 140                 ;
 141         return(tmp - dst); /* DAVIDM should we count a NUL ?  check getname */
 142 }
 143
 144 /*
 145  * Return the size of a string (including the ending 0)
 146  *
 147  * Return 0 on exception, a value greater than N if too long
 148  */
 149 static inline long strnlen_user(const char *src, long n)
 150 {
 151         return(strlen(src) + 1); /* DAVIDM make safer */
 152 }
 153
 154 #define strlen_user(str) strnlen_user(str, 32767)
 155
 156 /*
 157  * Zero Userspace
 158  */
 159
 160 static inline unsigned long
 161 clear_user(void *to, unsigned long n)
 162 {
 163         memset(to, 0, n);
 164         return 0;
 165 }
 166
 167 #endif /* _H8300_UACCESS_H */