arch/h8300/include/asm/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 #define access_ok(type, addr, size) __access_ok((unsigned long)addr,size)
  18 static inline int __access_ok(unsigned long addr, unsigned long size)
  19 {
  20 #define RANGE_CHECK_OK(addr, size, lower, upper) \
  21         (((addr) >= (lower)) && (((addr) + (size)) < (upper)))
  22
  23         extern unsigned long _ramend;
  24         return(RANGE_CHECK_OK(addr, size, 0L, (unsigned long)&_ramend));
  25 }
  26
  27 /*
  28  * The exception table consists of pairs of addresses: the first is the
  29  * address of an instruction that is allowed to fault, and the second is
  30  * the address at which the program should continue.  No registers are
  31  * modified, so it is entirely up to the continuation code to figure out
  32  * what to do.
  33  *
  34  * All the routines below use bits of fixup code that are out of line
  35  * with the main instruction path.  This means when everything is well,
  36  * we don't even have to jump over them.  Further, they do not intrude
  37  * on our cache or tlb entries.
  38  */
  39
  40 struct exception_table_entry
  41 {
  42         unsigned long insn, fixup;
  43 };
  44
  45 /* Returns 0 if exception not found and fixup otherwise.  */
  46 extern unsigned long search_exception_table(unsigned long);
  47
  48
  49 /*
  50  * These are the main single-value transfer routines.  They automatically
  51  * use the right size if we just have the right pointer type.
  52  */
  53
  54 #define put_user(x, ptr)                                \
  55 ({                                                      \
  56     int __pu_err = 0;                                   \
  57     typeof(*(ptr)) __pu_val = (x);                      \
  58     switch (sizeof (*(ptr))) {                          \
  59     case 1:                                             \
  60     case 2:                                             \
  61     case 4:                                             \
  62         *(ptr) = (__pu_val);                            \
  63         break;                                          \
  64     case 8:                                             \
  65         memcpy(ptr, &__pu_val, sizeof (*(ptr)));        \
  66         break;                                          \
  67     default:                                            \
  68         __pu_err = __put_user_bad();                    \
  69         break;                                          \
  70     }                                                   \
  71     __pu_err;                                           \
  72 })
  73 #define __put_user(x, ptr) put_user(x, ptr)
  74
  75 extern int __put_user_bad(void);
  76
  77 /*
  78  * Tell gcc we read from memory instead of writing: this is because
  79  * we do not write to any memory gcc knows about, so there are no
  80  * aliasing issues.
  81  */
  82
  83 #define __ptr(x) ((unsigned long *)(x))
  84
  85 /*
  86  * Tell gcc we read from memory instead of writing: this is because
  87  * we do not write to any memory gcc knows about, so there are no
  88  * aliasing issues.
  89  */
  90
  91 #define get_user(x, ptr)                                        \
  92 ({                                                              \
  93     int __gu_err = 0;                                           \
  94     typeof(*(ptr)) __gu_val = *ptr;                             \
  95     switch (sizeof(*(ptr))) {                                   \
  96     case 1:                                                     \
  97     case 2:                                                     \
  98     case 4:                                                     \
  99     case 8:                                                     \
 100         break;                                                  \
 101     default:                                                    \
 102         __gu_err = __get_user_bad();                            \
 103         __gu_val = 0;                                           \
 104         break;                                                  \
 105     }                                                           \
 106     (x) = __gu_val;                                             \
 107     __gu_err;                                                   \
 108 })
 109 #define __get_user(x, ptr) get_user(x, ptr)
 110
 111 extern int __get_user_bad(void);
 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_from_user(to, from, n) copy_from_user(to, from, n)
 117 #define __copy_to_user(to, from, n) copy_to_user(to, from, n)
 118 #define __copy_to_user_inatomic __copy_to_user
 119 #define __copy_from_user_inatomic __copy_from_user
 120
 121 #define copy_to_user_ret(to,from,n,retval) ({ if (copy_to_user(to,from,n)) return retval; })
 122
 123 #define copy_from_user_ret(to,from,n,retval) ({ if (copy_from_user(to,from,n)) return retval; })
 124
 125 /*
 126  * Copy a null terminated string from userspace.
 127  */
 128
 129 static inline long
 130 strncpy_from_user(char *dst, const char *src, long count)
 131 {
 132         char *tmp;
 133         strncpy(dst, src, count);
 134         for (tmp = dst; *tmp && count > 0; tmp++, count--)
 135                 ;
 136         return(tmp - dst); /* DAVIDM should we count a NUL ?  check getname */
 137 }
 138
 139 /*
 140  * Return the size of a string (including the ending 0)
 141  *
 142  * Return 0 on exception, a value greater than N if too long
 143  */
 144 static inline long strnlen_user(const char *src, long n)
 145 {
 146         return(strlen(src) + 1); /* DAVIDM make safer */
 147 }
 148
 149 #define strlen_user(str) strnlen_user(str, 32767)
 150
 151 /*
 152  * Zero Userspace
 153  */
 154
 155 static inline unsigned long
 156 clear_user(void *to, unsigned long n)
 157 {
 158         memset(to, 0, n);
 159         return 0;
 160 }
 161
 162 #endif /* _H8300_UACCESS_H */