arch/m68k/include/asm/uaccess.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __M68K_UACCESS_H
   3 #define __M68K_UACCESS_H
   4
   5 #ifdef CONFIG_MMU
   6
   7 /*
   8  * User space memory access functions
   9  */
  10 #include <linux/compiler.h>
  11 #include <linux/types.h>
  12 #include <asm/segment.h>
  13 #include <asm/extable.h>
  14
  15 /* We let the MMU do all checking */
  16 static inline int access_ok(const void __user *addr,
  17                             unsigned long size)
  18 {
  19         return 1;
  20 }
  21
  22 /*
  23  * Not all varients of the 68k family support the notion of address spaces.
  24  * The traditional 680x0 parts do, and they use the sfc/dfc registers and
  25  * the "moves" instruction to access user space from kernel space. Other
  26  * family members like ColdFire don't support this, and only have a single
  27  * address space, and use the usual "move" instruction for user space access.
  28  *
  29  * Outside of this difference the user space access functions are the same.
  30  * So lets keep the code simple and just define in what we need to use.
  31  */
  32 #ifdef CONFIG_CPU_HAS_ADDRESS_SPACES
  33 #define MOVES   "moves"
  34 #else
  35 #define MOVES   "move"
  36 #endif
  37
  38 extern int __put_user_bad(void);
  39 extern int __get_user_bad(void);
  40
  41 #define __put_user_asm(res, x, ptr, bwl, reg, err)      \
  42 asm volatile ("\n"                                      \
  43         "1:     "MOVES"."#bwl"  %2,%1\n"                \
  44         "2:\n"                                          \
  45         "       .section .fixup,\"ax\"\n"               \
  46         "       .even\n"                                \
  47         "10:    moveq.l %3,%0\n"                        \
  48         "       jra 2b\n"                               \
  49         "       .previous\n"                            \
  50         "\n"                                            \
  51         "       .section __ex_table,\"a\"\n"            \
  52         "       .align  4\n"                            \
  53         "       .long   1b,10b\n"                       \
  54         "       .long   2b,10b\n"                       \
  55         "       .previous"                              \
  56         : "+d" (res), "=m" (*(ptr))                     \
  57         : #reg (x), "i" (err))
  58
  59 /*
  60  * These are the main single-value transfer routines.  They automatically
  61  * use the right size if we just have the right pointer type.
  62  */
  63
  64 #define __put_user(x, ptr)                                              \
  65 ({                                                                      \
  66         typeof(*(ptr)) __pu_val = (x);                                  \
  67         int __pu_err = 0;                                               \
  68         __chk_user_ptr(ptr);                                            \
  69         switch (sizeof (*(ptr))) {                                      \
  70         case 1:                                                         \
  71                 __put_user_asm(__pu_err, __pu_val, ptr, b, d, -EFAULT); \
  72                 break;                                                  \
  73         case 2:                                                         \
  74                 __put_user_asm(__pu_err, __pu_val, ptr, w, r, -EFAULT); \
  75                 break;                                                  \
  76         case 4:                                                         \
  77                 __put_user_asm(__pu_err, __pu_val, ptr, l, r, -EFAULT); \
  78                 break;                                                  \
  79         case 8:                                                         \
  80             {                                                           \
  81                 const void __user *__pu_ptr = (ptr);                    \
  82                 asm volatile ("\n"                                      \
  83                         "1:     "MOVES".l       %2,(%1)+\n"             \
  84                         "2:     "MOVES".l       %R2,(%1)\n"             \
  85                         "3:\n"                                          \
  86                         "       .section .fixup,\"ax\"\n"               \
  87                         "       .even\n"                                \
  88                         "10:    movel %3,%0\n"                          \
  89                         "       jra 3b\n"                               \
  90                         "       .previous\n"                            \
  91                         "\n"                                            \
  92                         "       .section __ex_table,\"a\"\n"            \
  93                         "       .align 4\n"                             \
  94                         "       .long 1b,10b\n"                         \
  95                         "       .long 2b,10b\n"                         \
  96                         "       .long 3b,10b\n"                         \
  97                         "       .previous"                              \
  98                         : "+d" (__pu_err), "+a" (__pu_ptr)              \
  99                         : "r" (__pu_val), "i" (-EFAULT)                 \
 100                         : "memory");                                    \
 101                 break;                                                  \
 102             }                                                           \
 103         default:                                                        \
 104                 __pu_err = __put_user_bad();                            \
 105                 break;                                                  \
 106         }                                                               \
 107         __pu_err;                                                       \
 108 })
 109 #define put_user(x, ptr)        __put_user(x, ptr)
 110
 111
 112 #define __get_user_asm(res, x, ptr, type, bwl, reg, err) ({             \
 113         type __gu_val;                                                  \
 114         asm volatile ("\n"                                              \
 115                 "1:     "MOVES"."#bwl"  %2,%1\n"                        \
 116                 "2:\n"                                                  \
 117                 "       .section .fixup,\"ax\"\n"                       \
 118                 "       .even\n"                                        \
 119                 "10:    move.l  %3,%0\n"                                \
 120                 "       sub.l   %1,%1\n"                                \
 121                 "       jra     2b\n"                                   \
 122                 "       .previous\n"                                    \
 123                 "\n"                                                    \
 124                 "       .section __ex_table,\"a\"\n"                    \
 125                 "       .align  4\n"                                    \
 126                 "       .long   1b,10b\n"                               \
 127                 "       .previous"                                      \
 128                 : "+d" (res), "=&" #reg (__gu_val)                      \
 129                 : "m" (*(ptr)), "i" (err));                             \
 130         (x) = (__force typeof(*(ptr)))(__force unsigned long)__gu_val;  \
 131 })
 132
 133 #define __get_user(x, ptr)                                              \
 134 ({                                                                      \
 135         int __gu_err = 0;                                               \
 136         __chk_user_ptr(ptr);                                            \
 137         switch (sizeof(*(ptr))) {                                       \
 138         case 1:                                                         \
 139                 __get_user_asm(__gu_err, x, ptr, u8, b, d, -EFAULT);    \
 140                 break;                                                  \
 141         case 2:                                                         \
 142                 __get_user_asm(__gu_err, x, ptr, u16, w, r, -EFAULT);   \
 143                 break;                                                  \
 144         case 4:                                                         \
 145                 __get_user_asm(__gu_err, x, ptr, u32, l, r, -EFAULT);   \
 146                 break;                                                  \
 147         case 8: {                                                       \
 148                 const void __user *__gu_ptr = (ptr);                    \
 149                 union {                                                 \
 150                         u64 l;                                          \
 151                         __typeof__(*(ptr)) t;                           \
 152                 } __gu_val;                                             \
 153                 asm volatile ("\n"                                      \
 154                         "1:     "MOVES".l       (%2)+,%1\n"             \
 155                         "2:     "MOVES".l       (%2),%R1\n"             \
 156                         "3:\n"                                          \
 157                         "       .section .fixup,\"ax\"\n"               \
 158                         "       .even\n"                                \
 159                         "10:    move.l  %3,%0\n"                        \
 160                         "       sub.l   %1,%1\n"                        \
 161                         "       sub.l   %R1,%R1\n"                      \
 162                         "       jra     3b\n"                           \
 163                         "       .previous\n"                            \
 164                         "\n"                                            \
 165                         "       .section __ex_table,\"a\"\n"            \
 166                         "       .align  4\n"                            \
 167                         "       .long   1b,10b\n"                       \
 168                         "       .long   2b,10b\n"                       \
 169                         "       .previous"                              \
 170                         : "+d" (__gu_err), "=&r" (__gu_val.l),          \
 171                           "+a" (__gu_ptr)                               \
 172                         : "i" (-EFAULT)                                 \
 173                         : "memory");                                    \
 174                 (x) = __gu_val.t;                                       \
 175                 break;                                                  \
 176         }                                                               \
 177         default:                                                        \
 178                 __gu_err = __get_user_bad();                            \
 179                 break;                                                  \
 180         }                                                               \
 181         __gu_err;                                                       \
 182 })
 183 #define get_user(x, ptr) __get_user(x, ptr)
 184
 185 unsigned long __generic_copy_from_user(void *to, const void __user *from, unsigned long n);
 186 unsigned long __generic_copy_to_user(void __user *to, const void *from, unsigned long n);
 187
 188 #define __suffix0
 189 #define __suffix1 b
 190 #define __suffix2 w
 191 #define __suffix4 l
 192
 193 #define ____constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)\
 194         asm volatile ("\n"                                              \
 195                 "1:     "MOVES"."#s1"   (%2)+,%3\n"                     \
 196                 "       move."#s1"      %3,(%1)+\n"                     \
 197                 "       .ifnc   \""#s2"\",\"\"\n"                       \
 198                 "2:     "MOVES"."#s2"   (%2)+,%3\n"                     \
 199                 "       move."#s2"      %3,(%1)+\n"                     \
 200                 "       .ifnc   \""#s3"\",\"\"\n"                       \
 201                 "3:     "MOVES"."#s3"   (%2)+,%3\n"                     \
 202                 "       move."#s3"      %3,(%1)+\n"                     \
 203                 "       .endif\n"                                       \
 204                 "       .endif\n"                                       \
 205                 "4:\n"                                                  \
 206                 "       .section __ex_table,\"a\"\n"                    \
 207                 "       .align  4\n"                                    \
 208                 "       .long   1b,10f\n"                               \
 209                 "       .ifnc   \""#s2"\",\"\"\n"                       \
 210                 "       .long   2b,20f\n"                               \
 211                 "       .ifnc   \""#s3"\",\"\"\n"                       \
 212                 "       .long   3b,30f\n"                               \
 213                 "       .endif\n"                                       \
 214                 "       .endif\n"                                       \
 215                 "       .previous\n"                                    \
 216                 "\n"                                                    \
 217                 "       .section .fixup,\"ax\"\n"                       \
 218                 "       .even\n"                                        \
 219                 "10:    addq.l #"#n1",%0\n"                             \
 220                 "       .ifnc   \""#s2"\",\"\"\n"                       \
 221                 "20:    addq.l #"#n2",%0\n"                             \
 222                 "       .ifnc   \""#s3"\",\"\"\n"                       \
 223                 "30:    addq.l #"#n3",%0\n"                             \
 224                 "       .endif\n"                                       \
 225                 "       .endif\n"                                       \
 226                 "       jra     4b\n"                                   \
 227                 "       .previous\n"                                    \
 228                 : "+d" (res), "+&a" (to), "+a" (from), "=&d" (tmp)      \
 229                 : : "memory")
 230
 231 #define ___constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)\
 232         ____constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)
 233 #define __constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3)   \
 234         ___constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3,  \
 235                                         __suffix##n1, __suffix##n2, __suffix##n3)
 236
 237 static __always_inline unsigned long
 238 __constant_copy_from_user(void *to, const void __user *from, unsigned long n)
 239 {
 240         unsigned long res = 0, tmp;
 241
 242         switch (n) {
 243         case 1:
 244                 __constant_copy_from_user_asm(res, to, from, tmp, 1, 0, 0);
 245                 break;
 246         case 2:
 247                 __constant_copy_from_user_asm(res, to, from, tmp, 2, 0, 0);
 248                 break;
 249         case 3:
 250                 __constant_copy_from_user_asm(res, to, from, tmp, 2, 1, 0);
 251                 break;
 252         case 4:
 253                 __constant_copy_from_user_asm(res, to, from, tmp, 4, 0, 0);
 254                 break;
 255         case 5:
 256                 __constant_copy_from_user_asm(res, to, from, tmp, 4, 1, 0);
 257                 break;
 258         case 6:
 259                 __constant_copy_from_user_asm(res, to, from, tmp, 4, 2, 0);
 260                 break;
 261         case 7:
 262                 __constant_copy_from_user_asm(res, to, from, tmp, 4, 2, 1);
 263                 break;
 264         case 8:
 265                 __constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 0);
 266                 break;
 267         case 9:
 268                 __constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 1);
 269                 break;
 270         case 10:
 271                 __constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 2);
 272                 break;
 273         case 12:
 274                 __constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 4);
 275                 break;
 276         default:
 277                 /* we limit the inlined version to 3 moves */
 278                 return __generic_copy_from_user(to, from, n);
 279         }
 280
 281         return res;
 282 }
 283
 284 #define __constant_copy_to_user_asm(res, to, from, tmp, n, s1, s2, s3)  \
 285         asm volatile ("\n"                                              \
 286                 "       move."#s1"      (%2)+,%3\n"                     \
 287                 "11:    "MOVES"."#s1"   %3,(%1)+\n"                     \
 288                 "12:    move."#s2"      (%2)+,%3\n"                     \
 289                 "21:    "MOVES"."#s2"   %3,(%1)+\n"                     \
 290                 "22:\n"                                                 \
 291                 "       .ifnc   \""#s3"\",\"\"\n"                       \
 292                 "       move."#s3"      (%2)+,%3\n"                     \
 293                 "31:    "MOVES"."#s3"   %3,(%1)+\n"                     \
 294                 "32:\n"                                                 \
 295                 "       .endif\n"                                       \
 296                 "4:\n"                                                  \
 297                 "\n"                                                    \
 298                 "       .section __ex_table,\"a\"\n"                    \
 299                 "       .align  4\n"                                    \
 300                 "       .long   11b,5f\n"                               \
 301                 "       .long   12b,5f\n"                               \
 302                 "       .long   21b,5f\n"                               \
 303                 "       .long   22b,5f\n"                               \
 304                 "       .ifnc   \""#s3"\",\"\"\n"                       \
 305                 "       .long   31b,5f\n"                               \
 306                 "       .long   32b,5f\n"                               \
 307                 "       .endif\n"                                       \
 308                 "       .previous\n"                                    \
 309                 "\n"                                                    \
 310                 "       .section .fixup,\"ax\"\n"                       \
 311                 "       .even\n"                                        \
 312                 "5:     moveq.l #"#n",%0\n"                             \
 313                 "       jra     4b\n"                                   \
 314                 "       .previous\n"                                    \
 315                 : "+d" (res), "+a" (to), "+a" (from), "=&d" (tmp)       \
 316                 : : "memory")
 317
 318 static __always_inline unsigned long
 319 __constant_copy_to_user(void __user *to, const void *from, unsigned long n)
 320 {
 321         unsigned long res = 0, tmp;
 322
 323         switch (n) {
 324         case 1:
 325                 __put_user_asm(res, *(u8 *)from, (u8 __user *)to, b, d, 1);
 326                 break;
 327         case 2:
 328                 __put_user_asm(res, *(u16 *)from, (u16 __user *)to, w, r, 2);
 329                 break;
 330         case 3:
 331                 __constant_copy_to_user_asm(res, to, from, tmp, 3, w, b,);
 332                 break;
 333         case 4:
 334                 __put_user_asm(res, *(u32 *)from, (u32 __user *)to, l, r, 4);
 335                 break;
 336         case 5:
 337                 __constant_copy_to_user_asm(res, to, from, tmp, 5, l, b,);
 338                 break;
 339         case 6:
 340                 __constant_copy_to_user_asm(res, to, from, tmp, 6, l, w,);
 341                 break;
 342         case 7:
 343                 __constant_copy_to_user_asm(res, to, from, tmp, 7, l, w, b);
 344                 break;
 345         case 8:
 346                 __constant_copy_to_user_asm(res, to, from, tmp, 8, l, l,);
 347                 break;
 348         case 9:
 349                 __constant_copy_to_user_asm(res, to, from, tmp, 9, l, l, b);
 350                 break;
 351         case 10:
 352                 __constant_copy_to_user_asm(res, to, from, tmp, 10, l, l, w);
 353                 break;
 354         case 12:
 355                 __constant_copy_to_user_asm(res, to, from, tmp, 12, l, l, l);
 356                 break;
 357         default:
 358                 /* limit the inlined version to 3 moves */
 359                 return __generic_copy_to_user(to, from, n);
 360         }
 361
 362         return res;
 363 }
 364
 365 static inline unsigned long
 366 raw_copy_from_user(void *to, const void __user *from, unsigned long n)
 367 {
 368         if (__builtin_constant_p(n))
 369                 return __constant_copy_from_user(to, from, n);
 370         return __generic_copy_from_user(to, from, n);
 371 }
 372
 373 static inline unsigned long
 374 raw_copy_to_user(void __user *to, const void *from, unsigned long n)
 375 {
 376         if (__builtin_constant_p(n))
 377                 return __constant_copy_to_user(to, from, n);
 378         return __generic_copy_to_user(to, from, n);
 379 }
 380 #define INLINE_COPY_FROM_USER
 381 #define INLINE_COPY_TO_USER
 382
 383 #define user_addr_max() \
 384         (uaccess_kernel() ? ~0UL : TASK_SIZE)
 385
 386 extern long strncpy_from_user(char *dst, const char __user *src, long count);
 387 extern __must_check long strnlen_user(const char __user *str, long n);
 388
 389 unsigned long __clear_user(void __user *to, unsigned long n);
 390
 391 #define clear_user      __clear_user
 392
 393 #else /* !CONFIG_MMU */
 394 #include <asm-generic/uaccess.h>
 395 #endif
 396
 397 #endif /* _M68K_UACCESS_H */