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         /*
  20          * XXX: for !CONFIG_CPU_HAS_ADDRESS_SPACES this really needs to check
  21          * for TASK_SIZE!
  22          */
  23         return 1;
  24 }
  25
  26 /*
  27  * Not all varients of the 68k family support the notion of address spaces.
  28  * The traditional 680x0 parts do, and they use the sfc/dfc registers and
  29  * the "moves" instruction to access user space from kernel space. Other
  30  * family members like ColdFire don't support this, and only have a single
  31  * address space, and use the usual "move" instruction for user space access.
  32  *
  33  * Outside of this difference the user space access functions are the same.
  34  * So lets keep the code simple and just define in what we need to use.
  35  */
  36 #ifdef CONFIG_CPU_HAS_ADDRESS_SPACES
  37 #define MOVES   "moves"
  38 #else
  39 #define MOVES   "move"
  40 #endif
  41
  42 #define __put_user_asm(res, x, ptr, bwl, reg, err)      \
  43 asm volatile ("\n"                                      \
  44         "1:     "MOVES"."#bwl"  %2,%1\n"                \
  45         "2:\n"                                          \
  46         "       .section .fixup,\"ax\"\n"               \
  47         "       .even\n"                                \
  48         "10:    moveq.l %3,%0\n"                        \
  49         "       jra 2b\n"                               \
  50         "       .previous\n"                            \
  51         "\n"                                            \
  52         "       .section __ex_table,\"a\"\n"            \
  53         "       .align  4\n"                            \
  54         "       .long   1b,10b\n"                       \
  55         "       .long   2b,10b\n"                       \
  56         "       .previous"                              \
  57         : "+d" (res), "=m" (*(ptr))                     \
  58         : #reg (x), "i" (err))
  59
  60 #define __put_user_asm8(res, x, ptr)                            \
  61 do {                                                            \
  62         const void *__pu_ptr = (const void __force *)(ptr);     \
  63                                                                 \
  64         asm volatile ("\n"                                      \
  65                 "1:     "MOVES".l %2,(%1)+\n"                   \
  66                 "2:     "MOVES".l %R2,(%1)\n"                   \
  67                 "3:\n"                                          \
  68                 "       .section .fixup,\"ax\"\n"               \
  69                 "       .even\n"                                \
  70                 "10:    movel %3,%0\n"                          \
  71                 "       jra 3b\n"                               \
  72                 "       .previous\n"                            \
  73                 "\n"                                            \
  74                 "       .section __ex_table,\"a\"\n"            \
  75                 "       .align 4\n"                             \
  76                 "       .long 1b,10b\n"                         \
  77                 "       .long 2b,10b\n"                         \
  78                 "       .long 3b,10b\n"                         \
  79                 "       .previous"                              \
  80                 : "+d" (res), "+a" (__pu_ptr)                   \
  81                 : "r" (x), "i" (-EFAULT)                        \
  82                 : "memory");                                    \
  83 } while (0)
  84
  85 /*
  86  * These are the main single-value transfer routines.  They automatically
  87  * use the right size if we just have the right pointer type.
  88  */
  89
  90 #define __put_user(x, ptr)                                              \
  91 ({                                                                      \
  92         typeof(*(ptr)) __pu_val = (x);                                  \
  93         int __pu_err = 0;                                               \
  94         __chk_user_ptr(ptr);                                            \
  95         switch (sizeof (*(ptr))) {                                      \
  96         case 1:                                                         \
  97                 __put_user_asm(__pu_err, __pu_val, ptr, b, d, -EFAULT); \
  98                 break;                                                  \
  99         case 2:                                                         \
 100                 __put_user_asm(__pu_err, __pu_val, ptr, w, r, -EFAULT); \
 101                 break;                                                  \
 102         case 4:                                                         \
 103                 __put_user_asm(__pu_err, __pu_val, ptr, l, r, -EFAULT); \
 104                 break;                                                  \
 105         case 8:                                                         \
 106                 __put_user_asm8(__pu_err, __pu_val, ptr);               \
 107                 break;                                                  \
 108         default:                                                        \
 109                 BUILD_BUG();                                            \
 110         }                                                               \
 111         __pu_err;                                                       \
 112 })
 113 #define put_user(x, ptr)        __put_user(x, ptr)
 114
 115
 116 #define __get_user_asm(res, x, ptr, type, bwl, reg, err) ({             \
 117         type __gu_val;                                                  \
 118         asm volatile ("\n"                                              \
 119                 "1:     "MOVES"."#bwl"  %2,%1\n"                        \
 120                 "2:\n"                                                  \
 121                 "       .section .fixup,\"ax\"\n"                       \
 122                 "       .even\n"                                        \
 123                 "10:    move.l  %3,%0\n"                                \
 124                 "       sub.l   %1,%1\n"                                \
 125                 "       jra     2b\n"                                   \
 126                 "       .previous\n"                                    \
 127                 "\n"                                                    \
 128                 "       .section __ex_table,\"a\"\n"                    \
 129                 "       .align  4\n"                                    \
 130                 "       .long   1b,10b\n"                               \
 131                 "       .previous"                                      \
 132                 : "+d" (res), "=&" #reg (__gu_val)                      \
 133                 : "m" (*(ptr)), "i" (err));                             \
 134         (x) = (__force typeof(*(ptr)))(__force unsigned long)__gu_val;  \
 135 })
 136
 137 #define __get_user_asm8(res, x, ptr)                                    \
 138 do {                                                                    \
 139         const void *__gu_ptr = (const void __force *)(ptr);             \
 140         union {                                                         \
 141                 u64 l;                                                  \
 142                 __typeof__(*(ptr)) t;                                   \
 143         } __gu_val;                                                     \
 144                                                                         \
 145         asm volatile ("\n"                                              \
 146                 "1:     "MOVES".l       (%2)+,%1\n"                     \
 147                 "2:     "MOVES".l       (%2),%R1\n"                     \
 148                 "3:\n"                                                  \
 149                 "       .section .fixup,\"ax\"\n"                       \
 150                 "       .even\n"                                        \
 151                 "10:    move.l  %3,%0\n"                                \
 152                 "       sub.l   %1,%1\n"                                \
 153                 "       sub.l   %R1,%R1\n"                              \
 154                 "       jra     3b\n"                                   \
 155                 "       .previous\n"                                    \
 156                 "\n"                                                    \
 157                 "       .section __ex_table,\"a\"\n"                    \
 158                 "       .align  4\n"                                    \
 159                 "       .long   1b,10b\n"                               \
 160                 "       .long   2b,10b\n"                               \
 161                 "       .previous"                                      \
 162                 : "+d" (res), "=&r" (__gu_val.l),                       \
 163                   "+a" (__gu_ptr)                                       \
 164                 : "i" (-EFAULT)                                         \
 165                 : "memory");                                            \
 166         (x) = __gu_val.t;                                               \
 167 } while (0)
 168
 169 #define __get_user(x, ptr)                                              \
 170 ({                                                                      \
 171         int __gu_err = 0;                                               \
 172         __chk_user_ptr(ptr);                                            \
 173         switch (sizeof(*(ptr))) {                                       \
 174         case 1:                                                         \
 175                 __get_user_asm(__gu_err, x, ptr, u8, b, d, -EFAULT);    \
 176                 break;                                                  \
 177         case 2:                                                         \
 178                 __get_user_asm(__gu_err, x, ptr, u16, w, r, -EFAULT);   \
 179                 break;                                                  \
 180         case 4:                                                         \
 181                 __get_user_asm(__gu_err, x, ptr, u32, l, r, -EFAULT);   \
 182                 break;                                                  \
 183         case 8:                                                         \
 184                 __get_user_asm8(__gu_err, x, ptr);                      \
 185                 break;                                                  \
 186         default:                                                        \
 187                 BUILD_BUG();                                            \
 188         }                                                               \
 189         __gu_err;                                                       \
 190 })
 191 #define get_user(x, ptr) __get_user(x, ptr)
 192
 193 unsigned long __generic_copy_from_user(void *to, const void __user *from, unsigned long n);
 194 unsigned long __generic_copy_to_user(void __user *to, const void *from, unsigned long n);
 195
 196 #define __suffix0
 197 #define __suffix1 b
 198 #define __suffix2 w
 199 #define __suffix4 l
 200
 201 #define ____constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)\
 202         asm volatile ("\n"                                              \
 203                 "1:     "MOVES"."#s1"   (%2)+,%3\n"                     \
 204                 "       move."#s1"      %3,(%1)+\n"                     \
 205                 "       .ifnc   \""#s2"\",\"\"\n"                       \
 206                 "2:     "MOVES"."#s2"   (%2)+,%3\n"                     \
 207                 "       move."#s2"      %3,(%1)+\n"                     \
 208                 "       .ifnc   \""#s3"\",\"\"\n"                       \
 209                 "3:     "MOVES"."#s3"   (%2)+,%3\n"                     \
 210                 "       move."#s3"      %3,(%1)+\n"                     \
 211                 "       .endif\n"                                       \
 212                 "       .endif\n"                                       \
 213                 "4:\n"                                                  \
 214                 "       .section __ex_table,\"a\"\n"                    \
 215                 "       .align  4\n"                                    \
 216                 "       .long   1b,10f\n"                               \
 217                 "       .ifnc   \""#s2"\",\"\"\n"                       \
 218                 "       .long   2b,20f\n"                               \
 219                 "       .ifnc   \""#s3"\",\"\"\n"                       \
 220                 "       .long   3b,30f\n"                               \
 221                 "       .endif\n"                                       \
 222                 "       .endif\n"                                       \
 223                 "       .previous\n"                                    \
 224                 "\n"                                                    \
 225                 "       .section .fixup,\"ax\"\n"                       \
 226                 "       .even\n"                                        \
 227                 "10:    addq.l #"#n1",%0\n"                             \
 228                 "       .ifnc   \""#s2"\",\"\"\n"                       \
 229                 "20:    addq.l #"#n2",%0\n"                             \
 230                 "       .ifnc   \""#s3"\",\"\"\n"                       \
 231                 "30:    addq.l #"#n3",%0\n"                             \
 232                 "       .endif\n"                                       \
 233                 "       .endif\n"                                       \
 234                 "       jra     4b\n"                                   \
 235                 "       .previous\n"                                    \
 236                 : "+d" (res), "+&a" (to), "+a" (from), "=&d" (tmp)      \
 237                 : : "memory")
 238
 239 #define ___constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)\
 240         ____constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)
 241 #define __constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3)   \
 242         ___constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3,  \
 243                                         __suffix##n1, __suffix##n2, __suffix##n3)
 244
 245 static __always_inline unsigned long
 246 __constant_copy_from_user(void *to, const void __user *from, unsigned long n)
 247 {
 248         unsigned long res = 0, tmp;
 249
 250         switch (n) {
 251         case 1:
 252                 __constant_copy_from_user_asm(res, to, from, tmp, 1, 0, 0);
 253                 break;
 254         case 2:
 255                 __constant_copy_from_user_asm(res, to, from, tmp, 2, 0, 0);
 256                 break;
 257         case 3:
 258                 __constant_copy_from_user_asm(res, to, from, tmp, 2, 1, 0);
 259                 break;
 260         case 4:
 261                 __constant_copy_from_user_asm(res, to, from, tmp, 4, 0, 0);
 262                 break;
 263         case 5:
 264                 __constant_copy_from_user_asm(res, to, from, tmp, 4, 1, 0);
 265                 break;
 266         case 6:
 267                 __constant_copy_from_user_asm(res, to, from, tmp, 4, 2, 0);
 268                 break;
 269         case 7:
 270                 __constant_copy_from_user_asm(res, to, from, tmp, 4, 2, 1);
 271                 break;
 272         case 8:
 273                 __constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 0);
 274                 break;
 275         case 9:
 276                 __constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 1);
 277                 break;
 278         case 10:
 279                 __constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 2);
 280                 break;
 281         case 12:
 282                 __constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 4);
 283                 break;
 284         default:
 285                 /* we limit the inlined version to 3 moves */
 286                 return __generic_copy_from_user(to, from, n);
 287         }
 288
 289         return res;
 290 }
 291
 292 #define __constant_copy_to_user_asm(res, to, from, tmp, n, s1, s2, s3)  \
 293         asm volatile ("\n"                                              \
 294                 "       move."#s1"      (%2)+,%3\n"                     \
 295                 "11:    "MOVES"."#s1"   %3,(%1)+\n"                     \
 296                 "12:    move."#s2"      (%2)+,%3\n"                     \
 297                 "21:    "MOVES"."#s2"   %3,(%1)+\n"                     \
 298                 "22:\n"                                                 \
 299                 "       .ifnc   \""#s3"\",\"\"\n"                       \
 300                 "       move."#s3"      (%2)+,%3\n"                     \
 301                 "31:    "MOVES"."#s3"   %3,(%1)+\n"                     \
 302                 "32:\n"                                                 \
 303                 "       .endif\n"                                       \
 304                 "4:\n"                                                  \
 305                 "\n"                                                    \
 306                 "       .section __ex_table,\"a\"\n"                    \
 307                 "       .align  4\n"                                    \
 308                 "       .long   11b,5f\n"                               \
 309                 "       .long   12b,5f\n"                               \
 310                 "       .long   21b,5f\n"                               \
 311                 "       .long   22b,5f\n"                               \
 312                 "       .ifnc   \""#s3"\",\"\"\n"                       \
 313                 "       .long   31b,5f\n"                               \
 314                 "       .long   32b,5f\n"                               \
 315                 "       .endif\n"                                       \
 316                 "       .previous\n"                                    \
 317                 "\n"                                                    \
 318                 "       .section .fixup,\"ax\"\n"                       \
 319                 "       .even\n"                                        \
 320                 "5:     moveq.l #"#n",%0\n"                             \
 321                 "       jra     4b\n"                                   \
 322                 "       .previous\n"                                    \
 323                 : "+d" (res), "+a" (to), "+a" (from), "=&d" (tmp)       \
 324                 : : "memory")
 325
 326 static __always_inline unsigned long
 327 __constant_copy_to_user(void __user *to, const void *from, unsigned long n)
 328 {
 329         unsigned long res = 0, tmp;
 330
 331         switch (n) {
 332         case 1:
 333                 __put_user_asm(res, *(u8 *)from, (u8 __user *)to, b, d, 1);
 334                 break;
 335         case 2:
 336                 __put_user_asm(res, *(u16 *)from, (u16 __user *)to, w, r, 2);
 337                 break;
 338         case 3:
 339                 __constant_copy_to_user_asm(res, to, from, tmp, 3, w, b,);
 340                 break;
 341         case 4:
 342                 __put_user_asm(res, *(u32 *)from, (u32 __user *)to, l, r, 4);
 343                 break;
 344         case 5:
 345                 __constant_copy_to_user_asm(res, to, from, tmp, 5, l, b,);
 346                 break;
 347         case 6:
 348                 __constant_copy_to_user_asm(res, to, from, tmp, 6, l, w,);
 349                 break;
 350         case 7:
 351                 __constant_copy_to_user_asm(res, to, from, tmp, 7, l, w, b);
 352                 break;
 353         case 8:
 354                 __constant_copy_to_user_asm(res, to, from, tmp, 8, l, l,);
 355                 break;
 356         case 9:
 357                 __constant_copy_to_user_asm(res, to, from, tmp, 9, l, l, b);
 358                 break;
 359         case 10:
 360                 __constant_copy_to_user_asm(res, to, from, tmp, 10, l, l, w);
 361                 break;
 362         case 12:
 363                 __constant_copy_to_user_asm(res, to, from, tmp, 12, l, l, l);
 364                 break;
 365         default:
 366                 /* limit the inlined version to 3 moves */
 367                 return __generic_copy_to_user(to, from, n);
 368         }
 369
 370         return res;
 371 }
 372
 373 static inline unsigned long
 374 raw_copy_from_user(void *to, const void __user *from, unsigned long n)
 375 {
 376         if (__builtin_constant_p(n))
 377                 return __constant_copy_from_user(to, from, n);
 378         return __generic_copy_from_user(to, from, n);
 379 }
 380
 381 static inline unsigned long
 382 raw_copy_to_user(void __user *to, const void *from, unsigned long n)
 383 {
 384         if (__builtin_constant_p(n))
 385                 return __constant_copy_to_user(to, from, n);
 386         return __generic_copy_to_user(to, from, n);
 387 }
 388 #define INLINE_COPY_FROM_USER
 389 #define INLINE_COPY_TO_USER
 390
 391 #define user_addr_max() \
 392         (uaccess_kernel() ? ~0UL : TASK_SIZE)
 393
 394 extern long strncpy_from_user(char *dst, const char __user *src, long count);
 395 extern __must_check long strnlen_user(const char __user *str, long n);
 396
 397 unsigned long __clear_user(void __user *to, unsigned long n);
 398
 399 #define clear_user      __clear_user
 400
 401 #else /* !CONFIG_MMU */
 402 #include <asm-generic/uaccess.h>
 403 #endif
 404
 405 #endif /* _M68K_UACCESS_H */