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 #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 static inline int verify_area(int type, const void *addr, unsigned long size)
  28 {
  29         return access_ok(type,addr,size)?0:-EFAULT;
  30 }
  31
  32 /*
  33  * The exception table consists of pairs of addresses: the first is the
  34  * address of an instruction that is allowed to fault, and the second is
  35  * the address at which the program should continue.  No registers are
  36  * modified, so it is entirely up to the continuation code to figure out
  37  * what to do.
  38  *
  39  * All the routines below use bits of fixup code that are out of line
  40  * with the main instruction path.  This means when everything is well,
  41  * we don't even have to jump over them.  Further, they do not intrude
  42  * on our cache or tlb entries.
  43  */
  44
  45 struct exception_table_entry
  46 {
  47         unsigned long insn, fixup;
  48 };
  49
  50 /* Returns 0 if exception not found and fixup otherwise.  */
  51 extern unsigned long search_exception_table(unsigned long);
  52
  53
  54 /*
  55  * These are the main single-value transfer routines.  They automatically
  56  * use the right size if we just have the right pointer type.
  57  */
  58
  59 #define put_user(x, ptr)                                \
  60 ({                                                      \
  61     int __pu_err = 0;                                   \
  62     typeof(*(ptr)) __pu_val = (x);                      \
  63     switch (sizeof (*(ptr))) {                          \
  64     case 1:                                             \
  65     case 2:                                             \
  66     case 4:                                             \
  67         *(ptr) = (__pu_val);                            \
  68         break;                                          \
  69     case 8:                                             \
  70         memcpy(ptr, &__pu_val, sizeof (*(ptr)));        \
  71         break;                                          \
  72     default:                                            \
  73         __pu_err = __put_user_bad();                    \
  74         break;                                          \
  75     }                                                   \
  76     __pu_err;                                           \
  77 })
  78 #define __put_user(x, ptr) put_user(x, ptr)
  79
  80 extern int __put_user_bad(void);
  81
  82 /*
  83  * Tell gcc we read from memory instead of writing: this is because
  84  * we do not write to any memory gcc knows about, so there are no
  85  * aliasing issues.
  86  */
  87
  88 #define __ptr(x) ((unsigned long *)(x))
  89
  90 /*
  91  * Tell gcc we read from memory instead of writing: this is because
  92  * we do not write to any memory gcc knows about, so there are no
  93  * aliasing issues.
  94  */
  95
  96 #define get_user(x, ptr)                                        \
  97 ({                                                              \
  98     int __gu_err = 0;                                           \
  99     typeof(*(ptr)) __gu_val = 0;                                \
 100     switch (sizeof(*(ptr))) {                                   \
 101     case 1:                                                     \
 102     case 2:                                                     \
 103     case 4:                                                     \
 104         __gu_val = *(ptr);                                      \
 105         break;                                                  \
 106     case 8:                                                     \
 107         memcpy(&__gu_val, ptr, sizeof (*(ptr)));                \
 108         break;                                                  \
 109     default:                                                    \
 110         __gu_val = 0;                                           \
 111         __gu_err = __get_user_bad();                            \
 112         break;                                                  \
 113     }                                                           \
 114     (x) = __gu_val;                                             \
 115     __gu_err;                                                   \
 116 })
 117 #define __get_user(x, ptr) get_user(x, ptr)
 118
 119 extern int __get_user_bad(void);
 120
 121 #define copy_from_user(to, from, n)             (memcpy(to, from, n), 0)
 122 #define copy_to_user(to, from, n)               (memcpy(to, from, n), 0)
 123
 124 #define __copy_from_user(to, from, n) copy_from_user(to, from, n)
 125 #define __copy_to_user(to, from, n) copy_to_user(to, from, n)
 126 #define __copy_to_user_inatomic __copy_to_user
 127 #define __copy_from_user_inatomic __copy_from_user
 128
 129 #define copy_to_user_ret(to,from,n,retval) ({ if (copy_to_user(to,from,n)) return retval; })
 130
 131 #define copy_from_user_ret(to,from,n,retval) ({ if (copy_from_user(to,from,n)) return retval; })
 132
 133 /*
 134  * Copy a null terminated string from userspace.
 135  */
 136
 137 static inline long
 138 strncpy_from_user(char *dst, const char *src, long count)
 139 {
 140         char *tmp;
 141         strncpy(dst, src, count);
 142         for (tmp = dst; *tmp && count > 0; tmp++, count--)
 143                 ;
 144         return(tmp - dst); /* DAVIDM should we count a NUL ?  check getname */
 145 }
 146
 147 /*
 148  * Return the size of a string (including the ending 0)
 149  *
 150  * Return 0 on exception, a value greater than N if too long
 151  */
 152 static inline long strnlen_user(const char *src, long n)
 153 {
 154         return(strlen(src) + 1); /* DAVIDM make safer */
 155 }
 156
 157 #define strlen_user(str) strnlen_user(str, 32767)
 158
 159 /*
 160  * Zero Userspace
 161  */
 162
 163 static inline unsigned long
 164 clear_user(void *to, unsigned long n)
 165 {
 166         memset(to, 0, n);
 167         return 0;
 168 }
 169
 170 #endif /* _H8300_UACCESS_H */