include/asm-frv/uaccess.h

   1 /* uaccess.h: userspace accessor functions
   2  *
   3  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #ifndef _ASM_UACCESS_H
  13 #define _ASM_UACCESS_H
  14
  15 /*
  16  * User space memory access functions
  17  */
  18 #include <linux/sched.h>
  19 #include <linux/mm.h>
  20 #include <asm/segment.h>
  21 #include <asm/sections.h>
  22
  23 #define HAVE_ARCH_UNMAPPED_AREA /* we decide where to put mmaps */
  24
  25 #define __ptr(x) ((unsigned long *)(x))
  26
  27 #define VERIFY_READ     0
  28 #define VERIFY_WRITE    1
  29
  30 #define __addr_ok(addr) ((unsigned long)(addr) < get_addr_limit())
  31
  32 /*
  33  * check that a range of addresses falls within the current address limit
  34  */
  35 static inline int ___range_ok(unsigned long addr, unsigned long size)
  36 {
  37 #ifdef CONFIG_MMU
  38         int flag = -EFAULT, tmp;
  39
  40         asm volatile (
  41                 "       addcc   %3,%2,%1,icc0   \n"     /* set C-flag if addr+size>4GB */
  42                 "       subcc.p %1,%4,gr0,icc1  \n"     /* jump if addr+size>limit */
  43                 "       bc      icc0,#0,0f      \n"
  44                 "       bhi     icc1,#0,0f      \n"
  45                 "       setlos  #0,%0           \n"     /* mark okay */
  46                 "0:                             \n"
  47                 : "=r"(flag), "=&r"(tmp)
  48                 : "r"(addr), "r"(size), "r"(get_addr_limit()), "0"(flag)
  49                 );
  50
  51         return flag;
  52
  53 #else
  54
  55         if (addr < memory_start ||
  56             addr > memory_end ||
  57             size > memory_end - memory_start ||
  58             addr + size > memory_end)
  59                 return -EFAULT;
  60
  61         return 0;
  62 #endif
  63 }
  64
  65 #define __range_ok(addr,size) ___range_ok((unsigned long) (addr), (unsigned long) (size))
  66
  67 #define access_ok(type,addr,size) (__range_ok((addr), (size)) == 0)
  68 #define __access_ok(addr,size) (__range_ok((addr), (size)) == 0)
  69
  70 /*
  71  * The exception table consists of pairs of addresses: the first is the
  72  * address of an instruction that is allowed to fault, and the second is
  73  * the address at which the program should continue.  No registers are
  74  * modified, so it is entirely up to the continuation code to figure out
  75  * what to do.
  76  *
  77  * All the routines below use bits of fixup code that are out of line
  78  * with the main instruction path.  This means when everything is well,
  79  * we don't even have to jump over them.  Further, they do not intrude
  80  * on our cache or tlb entries.
  81  */
  82 struct exception_table_entry
  83 {
  84         unsigned long insn, fixup;
  85 };
  86
  87 /* Returns 0 if exception not found and fixup otherwise.  */
  88 extern unsigned long search_exception_table(unsigned long);
  89
  90
  91 /*
  92  * These are the main single-value transfer routines.  They automatically
  93  * use the right size if we just have the right pointer type.
  94  */
  95 #define __put_user(x, ptr)                                              \
  96 ({                                                                      \
  97         int __pu_err = 0;                                               \
  98                                                                         \
  99         typeof(*(ptr)) __pu_val = (x);                                  \
 100                                                                         \
 101         switch (sizeof (*(ptr))) {                                      \
 102         case 1:                                                         \
 103                 __put_user_asm(__pu_err, __pu_val, ptr, "b", "r");      \
 104                 break;                                                  \
 105         case 2:                                                         \
 106                 __put_user_asm(__pu_err, __pu_val, ptr, "h", "r");      \
 107                 break;                                                  \
 108         case 4:                                                         \
 109                 __put_user_asm(__pu_err, __pu_val, ptr, "",  "r");      \
 110                 break;                                                  \
 111         case 8:                                                         \
 112                 __put_user_asm(__pu_err, __pu_val, ptr, "d", "e");      \
 113                 break;                                                  \
 114         default:                                                        \
 115                 __pu_err = __put_user_bad();                            \
 116                 break;                                                  \
 117         }                                                               \
 118         __pu_err;                                                       \
 119 })
 120
 121 #define put_user(x, ptr)                        \
 122 ({                                              \
 123         typeof(&*ptr) _p = (ptr);               \
 124         int _e;                                 \
 125                                                 \
 126         _e = __range_ok(_p, sizeof(*_p));       \
 127         if (_e == 0)                            \
 128                 _e = __put_user((x), _p);       \
 129         _e;                                     \
 130 })
 131
 132 extern int __put_user_bad(void);
 133
 134 /*
 135  * Tell gcc we read from memory instead of writing: this is because
 136  * we do not write to any memory gcc knows about, so there are no
 137  * aliasing issues.
 138  */
 139
 140 #ifdef CONFIG_MMU
 141
 142 #define __put_user_asm(err,x,ptr,dsize,constraint)                                      \
 143 do {                                                                                    \
 144         asm volatile("1:        st"dsize"%I1    %2,%M1  \n"                             \
 145                      "2:                                \n"                             \
 146                      ".subsection 2                     \n"                             \
 147                      "3:        setlos          %3,%0   \n"                             \
 148                      "          bra             2b      \n"                             \
 149                      ".previous                         \n"                             \
 150                      ".section __ex_table,\"a\"         \n"                             \
 151                      "          .balign         8       \n"                             \
 152                      "          .long           1b,3b   \n"                             \
 153                      ".previous"                                                        \
 154                      : "=r" (err)                                                       \
 155                      : "m" (*__ptr(ptr)), constraint (x), "i"(-EFAULT), "0"(err)        \
 156                      : "memory");                                                       \
 157 } while (0)
 158
 159 #else
 160
 161 #define __put_user_asm(err,x,ptr,bwl,con)       \
 162 do {                                            \
 163         asm("   st"bwl"%I0      %1,%M0  \n"     \
 164             "   membar                  \n"     \
 165             :                                   \
 166             : "m" (*__ptr(ptr)), con (x)        \
 167             : "memory");                        \
 168 } while (0)
 169
 170 #endif
 171
 172 /*****************************************************************************/
 173 /*
 174  *
 175  */
 176 #define __get_user(x, ptr)                                              \
 177 ({                                                                      \
 178         typeof(*(ptr)) __gu_val = 0;                                    \
 179         int __gu_err = 0;                                               \
 180                                                                         \
 181         switch (sizeof(*(ptr))) {                                       \
 182         case 1:                                                         \
 183                 __get_user_asm(__gu_err, *(u8*)&__gu_val, ptr, "ub", "=r"); \
 184                 break;                                                  \
 185         case 2:                                                         \
 186                 __get_user_asm(__gu_err, *(u16*)&__gu_val, ptr, "uh", "=r"); \
 187                 break;                                                  \
 188         case 4:                                                         \
 189                 __get_user_asm(__gu_err, *(u32*)&__gu_val, ptr, "", "=r"); \
 190                 break;                                                  \
 191         case 8:                                                         \
 192                 __get_user_asm(__gu_err, *(u64*)&__gu_val, ptr, "d", "=e"); \
 193                 break;                                                  \
 194         default:                                                        \
 195                 __gu_err = __get_user_bad();                            \
 196                 break;                                                  \
 197         }                                                               \
 198         (x) = __gu_val;                                                 \
 199         __gu_err;                                                       \
 200 })
 201
 202 #define get_user(x, ptr)                        \
 203 ({                                              \
 204         typeof(&*ptr) _p = (ptr);               \
 205         int _e;                                 \
 206                                                 \
 207         _e = __range_ok(_p, sizeof(*_p));       \
 208         if (likely(_e == 0))                    \
 209                 _e = __get_user((x), _p);       \
 210         else                                    \
 211                 (x) = (typeof(x)) 0;            \
 212         _e;                                     \
 213 })
 214
 215 extern int __get_user_bad(void);
 216
 217 #ifdef CONFIG_MMU
 218
 219 #define __get_user_asm(err,x,ptr,dtype,constraint)      \
 220 do {                                                    \
 221         asm("1:         ld"dtype"%I2    %M2,%1  \n"     \
 222             "2:                                 \n"     \
 223             ".subsection 2                      \n"     \
 224             "3:         setlos          %3,%0   \n"     \
 225             "           setlos          #0,%1   \n"     \
 226             "           bra             2b      \n"     \
 227             ".previous                          \n"     \
 228             ".section __ex_table,\"a\"          \n"     \
 229             "           .balign         8       \n"     \
 230             "           .long           1b,3b   \n"     \
 231             ".previous"                                 \
 232             : "=r" (err), constraint (x)                \
 233             : "m" (*__ptr(ptr)), "i"(-EFAULT), "0"(err) \
 234             );                                          \
 235 } while(0)
 236
 237 #else
 238
 239 #define __get_user_asm(err,x,ptr,bwl,con)       \
 240         asm("   ld"bwl"%I1      %M1,%0  \n"     \
 241             "   membar                  \n"     \
 242             : con(x)                            \
 243             : "m" (*__ptr(ptr)))
 244
 245 #endif
 246
 247 /*****************************************************************************/
 248 /*
 249  *
 250  */
 251 #ifdef CONFIG_MMU
 252 extern long __memset_user(void *dst, unsigned long count);
 253 extern long __memcpy_user(void *dst, const void *src, unsigned long count);
 254
 255 #define clear_user(dst,count)                   __memset_user((dst), (count))
 256 #define __copy_from_user_inatomic(to, from, n)  __memcpy_user((to), (from), (n))
 257 #define __copy_to_user_inatomic(to, from, n)    __memcpy_user((to), (from), (n))
 258
 259 #else
 260
 261 #define clear_user(dst,count)                   (memset((dst), 0, (count)), 0)
 262 #define __copy_from_user_inatomic(to, from, n)  (memcpy((to), (from), (n)), 0)
 263 #define __copy_to_user_inatomic(to, from, n)    (memcpy((to), (from), (n)), 0)
 264
 265 #endif
 266
 267 static inline unsigned long __must_check
 268 __copy_to_user(void __user *to, const void *from, unsigned long n)
 269 {
 270        might_sleep();
 271        return __copy_to_user_inatomic(to, from, n);
 272 }
 273
 274 static inline unsigned long
 275 __copy_from_user(void *to, const void __user *from, unsigned long n)
 276 {
 277        might_sleep();
 278        return __copy_from_user_inatomic(to, from, n);
 279 }
 280
 281 static inline long copy_from_user(void *to, const void *from, unsigned long n)
 282 {
 283         unsigned long ret = n;
 284
 285         if (likely(__access_ok(from, n)))
 286                 ret = __copy_from_user(to, from, n);
 287
 288         if (unlikely(ret != 0))
 289                 memset(to + (n - ret), 0, ret);
 290
 291         return ret;
 292 }
 293
 294 static inline long copy_to_user(void *to, const void *from, unsigned long n)
 295 {
 296         return likely(__access_ok(to, n)) ? __copy_to_user(to, from, n) : n;
 297 }
 298
 299 #define copy_to_user_ret(to,from,n,retval)      ({ if (copy_to_user(to,from,n)) return retval; })
 300 #define copy_from_user_ret(to,from,n,retval)    ({ if (copy_from_user(to,from,n)) return retval; })
 301
 302 extern long strncpy_from_user(char *dst, const char *src, long count);
 303 extern long strnlen_user(const char *src, long count);
 304
 305 #define strlen_user(str) strnlen_user(str, 32767)
 306
 307 extern unsigned long search_exception_table(unsigned long addr);
 308
 309 #endif /* _ASM_UACCESS_H */