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   1 #ifndef __M68KNOMMU_UACCESS_H
   2 #define __M68KNOMMU_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 #define access_ok(type,addr,size)       _access_ok((unsigned long)(addr),(size))
  17
  18 static inline int _access_ok(unsigned long addr, unsigned long size)
  19 {
  20         extern unsigned long memory_start, memory_end;
  21
  22         return (((addr >= memory_start) && (addr+size < memory_end)) ||
  23                 (is_in_rom(addr) && is_in_rom(addr+size)));
  24 }
  25
  26 /*
  27  * The exception table consists of pairs of addresses: the first is the
  28  * address of an instruction that is allowed to fault, and the second is
  29  * the address at which the program should continue.  No registers are
  30  * modified, so it is entirely up to the continuation code to figure out
  31  * what to do.
  32  *
  33  * All the routines below use bits of fixup code that are out of line
  34  * with the main instruction path.  This means when everything is well,
  35  * we don't even have to jump over them.  Further, they do not intrude
  36  * on our cache or tlb entries.
  37  */
  38
  39 struct exception_table_entry
  40 {
  41         unsigned long insn, fixup;
  42 };
  43
  44 /* Returns 0 if exception not found and fixup otherwise.  */
  45 extern unsigned long search_exception_table(unsigned long);
  46
  47
  48 /*
  49  * These are the main single-value transfer routines.  They automatically
  50  * use the right size if we just have the right pointer type.
  51  */
  52
  53 #define put_user(x, ptr)                                \
  54 ({                                                      \
  55     int __pu_err = 0;                                   \
  56     typeof(*(ptr)) __pu_val = (x);                      \
  57     switch (sizeof (*(ptr))) {                          \
  58     case 1:                                             \
  59         __put_user_asm(__pu_err, __pu_val, ptr, b);     \
  60         break;                                          \
  61     case 2:                                             \
  62         __put_user_asm(__pu_err, __pu_val, ptr, w);     \
  63         break;                                          \
  64     case 4:                                             \
  65         __put_user_asm(__pu_err, __pu_val, ptr, l);     \
  66         break;                                          \
  67     case 8:                                             \
  68         memcpy(ptr, &__pu_val, sizeof (*(ptr))); \
  69         break;                                          \
  70     default:                                            \
  71         __pu_err = __put_user_bad();                    \
  72         break;                                          \
  73     }                                                   \
  74     __pu_err;                                           \
  75 })
  76 #define __put_user(x, ptr) put_user(x, ptr)
  77
  78 extern int __put_user_bad(void);
  79
  80 /*
  81  * Tell gcc we read from memory instead of writing: this is because
  82  * we do not write to any memory gcc knows about, so there are no
  83  * aliasing issues.
  84  */
  85
  86 #define __ptr(x) ((unsigned long *)(x))
  87
  88 #define __put_user_asm(err,x,ptr,bwl)                           \
  89         __asm__ ("move" #bwl " %0,%1"                           \
  90                 : /* no outputs */                                              \
  91                 :"d" (x),"m" (*__ptr(ptr)) : "memory")
  92
  93 #define get_user(x, ptr)                                        \
  94 ({                                                              \
  95     int __gu_err = 0;                                           \
  96     typeof(x) __gu_val = 0;                                     \
  97     switch (sizeof(*(ptr))) {                                   \
  98     case 1:                                                     \
  99         __get_user_asm(__gu_err, __gu_val, ptr, b, "=d");       \
 100         break;                                                  \
 101     case 2:                                                     \
 102         __get_user_asm(__gu_err, __gu_val, ptr, w, "=r");       \
 103         break;                                                  \
 104     case 4:                                                     \
 105         __get_user_asm(__gu_err, __gu_val, ptr, l, "=r");       \
 106         break;                                                  \
 107     case 8:                                                     \
 108         memcpy((void *) &__gu_val, ptr, sizeof (*(ptr)));       \
 109         break;                                                  \
 110     default:                                                    \
 111         __gu_val = 0;                                           \
 112         __gu_err = __get_user_bad();                            \
 113         break;                                                  \
 114     }                                                           \
 115     (x) = (typeof(*(ptr))) __gu_val;                            \
 116     __gu_err;                                                   \
 117 })
 118 #define __get_user(x, ptr) get_user(x, ptr)
 119
 120 extern int __get_user_bad(void);
 121
 122 #define __get_user_asm(err,x,ptr,bwl,reg)                       \
 123         __asm__ ("move" #bwl " %1,%0"                           \
 124                  : "=d" (x)                                     \
 125                  : "m" (*__ptr(ptr)))
 126
 127 #define copy_from_user(to, from, n)             (memcpy(to, from, n), 0)
 128 #define copy_to_user(to, from, n)               (memcpy(to, from, n), 0)
 129
 130 #define __copy_from_user(to, from, n) copy_from_user(to, from, n)
 131 #define __copy_to_user(to, from, n) copy_to_user(to, from, n)
 132 #define __copy_to_user_inatomic __copy_to_user
 133 #define __copy_from_user_inatomic __copy_from_user
 134
 135 #define copy_to_user_ret(to,from,n,retval) ({ if (copy_to_user(to,from,n)) return retval; })
 136
 137 #define copy_from_user_ret(to,from,n,retval) ({ if (copy_from_user(to,from,n)) return retval; })
 138
 139 /*
 140  * Copy a null terminated string from userspace.
 141  */
 142
 143 static inline long
 144 strncpy_from_user(char *dst, const char *src, long count)
 145 {
 146         char *tmp;
 147         strncpy(dst, src, count);
 148         for (tmp = dst; *tmp && count > 0; tmp++, count--)
 149                 ;
 150         return(tmp - dst); /* DAVIDM should we count a NUL ?  check getname */
 151 }
 152
 153 /*
 154  * Return the size of a string (including the ending 0)
 155  *
 156  * Return 0 on exception, a value greater than N if too long
 157  */
 158 static inline long strnlen_user(const char *src, long n)
 159 {
 160         return(strlen(src) + 1); /* DAVIDM make safer */
 161 }
 162
 163 #define strlen_user(str) strnlen_user(str, 32767)
 164
 165 /*
 166  * Zero Userspace
 167  */
 168
 169 static inline unsigned long
 170 clear_user(void *to, unsigned long n)
 171 {
 172         memset(to, 0, n);
 173         return 0;
 174 }
 175
 176 #endif /* _M68KNOMMU_UACCESS_H */