arch/csky/include/asm/uaccess.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
   3
   4 #ifndef __ASM_CSKY_UACCESS_H
   5 #define __ASM_CSKY_UACCESS_H
   6
   7 /*
   8  * User space memory access functions
   9  */
  10 #include <linux/compiler.h>
  11 #include <linux/errno.h>
  12 #include <linux/types.h>
  13 #include <linux/sched.h>
  14 #include <linux/string.h>
  15 #include <linux/version.h>
  16 #include <asm/segment.h>
  17
  18 static inline int access_ok(const void *addr, unsigned long size)
  19 {
  20         unsigned long limit = current_thread_info()->addr_limit.seg;
  21
  22         return (((unsigned long)addr < limit) &&
  23                 ((unsigned long)(addr + size) < limit));
  24 }
  25
  26 #define __addr_ok(addr) (access_ok(addr, 0))
  27
  28 extern int __put_user_bad(void);
  29
  30 /*
  31  * Tell gcc we read from memory instead of writing: this is because
  32  * we do not write to any memory gcc knows about, so there are no
  33  * aliasing issues.
  34  */
  35
  36 /*
  37  * These are the main single-value transfer routines.  They automatically
  38  * use the right size if we just have the right pointer type.
  39  *
  40  * This gets kind of ugly. We want to return _two_ values in "get_user()"
  41  * and yet we don't want to do any pointers, because that is too much
  42  * of a performance impact. Thus we have a few rather ugly macros here,
  43  * and hide all the ugliness from the user.
  44  *
  45  * The "__xxx" versions of the user access functions are versions that
  46  * do not verify the address space, that must have been done previously
  47  * with a separate "access_ok()" call (this is used when we do multiple
  48  * accesses to the same area of user memory).
  49  *
  50  * As we use the same address space for kernel and user data on
  51  * Ckcore, we can just do these as direct assignments.  (Of course, the
  52  * exception handling means that it's no longer "just"...)
  53  */
  54
  55 #define put_user(x, ptr) \
  56         __put_user_check((x), (ptr), sizeof(*(ptr)))
  57
  58 #define __put_user(x, ptr) \
  59         __put_user_nocheck((x), (ptr), sizeof(*(ptr)))
  60
  61 #define __ptr(x) ((unsigned long *)(x))
  62
  63 #define get_user(x, ptr) \
  64         __get_user_check((x), (ptr), sizeof(*(ptr)))
  65
  66 #define __get_user(x, ptr) \
  67         __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
  68
  69 #define __put_user_nocheck(x, ptr, size)                                \
  70 ({                                                                      \
  71         long __pu_err = 0;                                              \
  72         typeof(*(ptr)) *__pu_addr = (ptr);                              \
  73         typeof(*(ptr)) __pu_val = (typeof(*(ptr)))(x);                  \
  74         if (__pu_addr)                                                  \
  75                 __put_user_size(__pu_val, (__pu_addr), (size),          \
  76                                 __pu_err);                              \
  77         __pu_err;                                                       \
  78 })
  79
  80 #define __put_user_check(x, ptr, size)                                  \
  81 ({                                                                      \
  82         long __pu_err = -EFAULT;                                        \
  83         typeof(*(ptr)) *__pu_addr = (ptr);                              \
  84         typeof(*(ptr)) __pu_val = (typeof(*(ptr)))(x);                  \
  85         if (access_ok(__pu_addr, size) && __pu_addr)    \
  86                 __put_user_size(__pu_val, __pu_addr, (size), __pu_err); \
  87         __pu_err;                                                       \
  88 })
  89
  90 #define __put_user_size(x, ptr, size, retval)           \
  91 do {                                                    \
  92         retval = 0;                                     \
  93         switch (size) {                                 \
  94         case 1:                                         \
  95                 __put_user_asm_b(x, ptr, retval);       \
  96                 break;                                  \
  97         case 2:                                         \
  98                 __put_user_asm_h(x, ptr, retval);       \
  99                 break;                                  \
 100         case 4:                                         \
 101                 __put_user_asm_w(x, ptr, retval);       \
 102                 break;                                  \
 103         case 8:                                         \
 104                 __put_user_asm_64(x, ptr, retval);      \
 105                 break;                                  \
 106         default:                                        \
 107                 __put_user_bad();                       \
 108         }                                               \
 109 } while (0)
 110
 111 /*
 112  * We don't tell gcc that we are accessing memory, but this is OK
 113  * because we do not write to any memory gcc knows about, so there
 114  * are no aliasing issues.
 115  *
 116  * Note that PC at a fault is the address *after* the faulting
 117  * instruction.
 118  */
 119 #define __put_user_asm_b(x, ptr, err)                   \
 120 do {                                                    \
 121         int errcode;                                    \
 122         asm volatile(                                   \
 123         "1:     stb   %1, (%2,0)        \n"             \
 124         "       br    3f                \n"             \
 125         "2:     mov   %0, %3            \n"             \
 126         "       br    3f                \n"             \
 127         ".section __ex_table, \"a\"     \n"             \
 128         ".align   2                     \n"             \
 129         ".long    1b,2b                 \n"             \
 130         ".previous                      \n"             \
 131         "3:                             \n"             \
 132         : "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode)  \
 133         : "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT)      \
 134         : "memory");                                    \
 135 } while (0)
 136
 137 #define __put_user_asm_h(x, ptr, err)                   \
 138 do {                                                    \
 139         int errcode;                                    \
 140         asm volatile(                                   \
 141         "1:     sth   %1, (%2,0)        \n"             \
 142         "       br    3f                \n"             \
 143         "2:     mov   %0, %3            \n"             \
 144         "       br    3f                \n"             \
 145         ".section __ex_table, \"a\"     \n"             \
 146         ".align   2                     \n"             \
 147         ".long    1b,2b                 \n"             \
 148         ".previous                      \n"             \
 149         "3:                             \n"             \
 150         : "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode)  \
 151         : "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT)      \
 152         : "memory");                                    \
 153 } while (0)
 154
 155 #define __put_user_asm_w(x, ptr, err)                   \
 156 do {                                                    \
 157         int errcode;                                    \
 158         asm volatile(                                   \
 159         "1:     stw   %1, (%2,0)        \n"             \
 160         "       br    3f                \n"             \
 161         "2:     mov   %0, %3            \n"             \
 162         "       br    3f                \n"             \
 163         ".section __ex_table,\"a\"      \n"             \
 164         ".align   2                     \n"             \
 165         ".long    1b, 2b                \n"             \
 166         ".previous                      \n"             \
 167         "3:                             \n"             \
 168         : "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode)  \
 169         : "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT)      \
 170         : "memory");                                    \
 171 } while (0)
 172
 173 #define __put_user_asm_64(x, ptr, err)                          \
 174 do {                                                            \
 175         int tmp;                                                \
 176         int errcode;                                            \
 177         typeof(*(ptr))src = (typeof(*(ptr)))x;                  \
 178         typeof(*(ptr))*psrc = &src;                             \
 179                                                                 \
 180         asm volatile(                                           \
 181         "     ldw     %3, (%1, 0)     \n"                       \
 182         "1:   stw     %3, (%2, 0)     \n"                       \
 183         "     ldw     %3, (%1, 4)     \n"                       \
 184         "2:   stw     %3, (%2, 4)     \n"                       \
 185         "     br      4f              \n"                       \
 186         "3:   mov     %0, %4          \n"                       \
 187         "     br      4f              \n"                       \
 188         ".section __ex_table, \"a\"   \n"                       \
 189         ".align   2                   \n"                       \
 190         ".long    1b, 3b              \n"                       \
 191         ".long    2b, 3b              \n"                       \
 192         ".previous                    \n"                       \
 193         "4:                           \n"                       \
 194         : "=r"(err), "=r"(psrc), "=r"(ptr),                     \
 195           "=r"(tmp), "=r"(errcode)                              \
 196         : "0"(err), "1"(psrc), "2"(ptr), "3"(0), "4"(-EFAULT)   \
 197         : "memory");                                            \
 198 } while (0)
 199
 200 #define __get_user_nocheck(x, ptr, size)                        \
 201 ({                                                              \
 202         long  __gu_err;                                         \
 203         __get_user_size(x, (ptr), (size), __gu_err);            \
 204         __gu_err;                                               \
 205 })
 206
 207 #define __get_user_check(x, ptr, size)                          \
 208 ({                                                              \
 209         int __gu_err = -EFAULT;                                 \
 210         const __typeof__(*(ptr)) __user *__gu_ptr = (ptr);      \
 211         if (access_ok(__gu_ptr, size) && __gu_ptr)      \
 212                 __get_user_size(x, __gu_ptr, size, __gu_err);   \
 213         __gu_err;                                               \
 214 })
 215
 216 #define __get_user_size(x, ptr, size, retval)                   \
 217 do {                                                            \
 218         switch (size) {                                         \
 219         case 1:                                                 \
 220                 __get_user_asm_common((x), ptr, "ldb", retval); \
 221                 break;                                          \
 222         case 2:                                                 \
 223                 __get_user_asm_common((x), ptr, "ldh", retval); \
 224                 break;                                          \
 225         case 4:                                                 \
 226                 __get_user_asm_common((x), ptr, "ldw", retval); \
 227                 break;                                          \
 228         default:                                                \
 229                 x = 0;                                          \
 230                 (retval) = __get_user_bad();                    \
 231         }                                                       \
 232 } while (0)
 233
 234 #define __get_user_asm_common(x, ptr, ins, err)                 \
 235 do {                                                            \
 236         int errcode;                                            \
 237         asm volatile(                                           \
 238         "1:   " ins " %1, (%4,0)        \n"                     \
 239         "       br    3f                \n"                     \
 240         /* Fix up codes */                                      \
 241         "2:     mov   %0, %2            \n"                     \
 242         "       movi  %1, 0             \n"                     \
 243         "       br    3f                \n"                     \
 244         ".section __ex_table,\"a\"      \n"                     \
 245         ".align   2                     \n"                     \
 246         ".long    1b, 2b                \n"                     \
 247         ".previous                      \n"                     \
 248         "3:                             \n"                     \
 249         : "=r"(err), "=r"(x), "=r"(errcode)                     \
 250         : "0"(0), "r"(ptr), "2"(-EFAULT)                        \
 251         : "memory");                                            \
 252 } while (0)
 253
 254 extern int __get_user_bad(void);
 255
 256 #define ___copy_to_user(to, from, n)                    \
 257 do {                                                    \
 258         int w0, w1, w2, w3;                             \
 259         asm volatile(                                   \
 260         "0:     cmpnei  %1, 0           \n"             \
 261         "       bf      8f              \n"             \
 262         "       mov     %3, %1          \n"             \
 263         "       or      %3, %2          \n"             \
 264         "       andi    %3, 3           \n"             \
 265         "       cmpnei  %3, 0           \n"             \
 266         "       bf      1f              \n"             \
 267         "       br      5f              \n"             \
 268         "1:     cmplti  %0, 16          \n" /* 4W */    \
 269         "       bt      3f              \n"             \
 270         "       ldw     %3, (%2, 0)     \n"             \
 271         "       ldw     %4, (%2, 4)     \n"             \
 272         "       ldw     %5, (%2, 8)     \n"             \
 273         "       ldw     %6, (%2, 12)    \n"             \
 274         "2:     stw     %3, (%1, 0)     \n"             \
 275         "9:     stw     %4, (%1, 4)     \n"             \
 276         "10:    stw     %5, (%1, 8)     \n"             \
 277         "11:    stw     %6, (%1, 12)    \n"             \
 278         "       addi    %2, 16          \n"             \
 279         "       addi    %1, 16          \n"             \
 280         "       subi    %0, 16          \n"             \
 281         "       br      1b              \n"             \
 282         "3:     cmplti  %0, 4           \n" /* 1W */    \
 283         "       bt      5f              \n"             \
 284         "       ldw     %3, (%2, 0)     \n"             \
 285         "4:     stw     %3, (%1, 0)     \n"             \
 286         "       addi    %2, 4           \n"             \
 287         "       addi    %1, 4           \n"             \
 288         "       subi    %0, 4           \n"             \
 289         "       br      3b              \n"             \
 290         "5:     cmpnei  %0, 0           \n"  /* 1B */   \
 291         "       bf      13f             \n"             \
 292         "       ldb     %3, (%2, 0)     \n"             \
 293         "6:     stb     %3, (%1, 0)     \n"             \
 294         "       addi    %2,  1          \n"             \
 295         "       addi    %1,  1          \n"             \
 296         "       subi    %0,  1          \n"             \
 297         "       br      5b              \n"             \
 298         "7:     subi    %0,  4          \n"             \
 299         "8:     subi    %0,  4          \n"             \
 300         "12:    subi    %0,  4          \n"             \
 301         "       br      13f             \n"             \
 302         ".section __ex_table, \"a\"     \n"             \
 303         ".align   2                     \n"             \
 304         ".long    2b, 13f               \n"             \
 305         ".long    4b, 13f               \n"             \
 306         ".long    6b, 13f               \n"             \
 307         ".long    9b, 12b               \n"             \
 308         ".long   10b, 8b                \n"             \
 309         ".long   11b, 7b                \n"             \
 310         ".previous                      \n"             \
 311         "13:                            \n"             \
 312         : "=r"(n), "=r"(to), "=r"(from), "=r"(w0),      \
 313           "=r"(w1), "=r"(w2), "=r"(w3)                  \
 314         : "0"(n), "1"(to), "2"(from)                    \
 315         : "memory");                                    \
 316 } while (0)
 317
 318 #define ___copy_from_user(to, from, n)                  \
 319 do {                                                    \
 320         int tmp;                                        \
 321         int nsave;                                      \
 322         asm volatile(                                   \
 323         "0:     cmpnei  %1, 0           \n"             \
 324         "       bf      7f              \n"             \
 325         "       mov     %3, %1          \n"             \
 326         "       or      %3, %2          \n"             \
 327         "       andi    %3, 3           \n"             \
 328         "       cmpnei  %3, 0           \n"             \
 329         "       bf      1f              \n"             \
 330         "       br      5f              \n"             \
 331         "1:     cmplti  %0, 16          \n"             \
 332         "       bt      3f              \n"             \
 333         "2:     ldw     %3, (%2, 0)     \n"             \
 334         "10:    ldw     %4, (%2, 4)     \n"             \
 335         "       stw     %3, (%1, 0)     \n"             \
 336         "       stw     %4, (%1, 4)     \n"             \
 337         "11:    ldw     %3, (%2, 8)     \n"             \
 338         "12:    ldw     %4, (%2, 12)    \n"             \
 339         "       stw     %3, (%1, 8)     \n"             \
 340         "       stw     %4, (%1, 12)    \n"             \
 341         "       addi    %2, 16          \n"             \
 342         "       addi    %1, 16          \n"             \
 343         "       subi    %0, 16          \n"             \
 344         "       br      1b              \n"             \
 345         "3:     cmplti  %0, 4           \n"             \
 346         "       bt      5f              \n"             \
 347         "4:     ldw     %3, (%2, 0)     \n"             \
 348         "       stw     %3, (%1, 0)     \n"             \
 349         "       addi    %2, 4           \n"             \
 350         "       addi    %1, 4           \n"             \
 351         "       subi    %0, 4           \n"             \
 352         "       br      3b              \n"             \
 353         "5:     cmpnei  %0, 0           \n"             \
 354         "       bf      7f              \n"             \
 355         "6:     ldb     %3, (%2, 0)     \n"             \
 356         "       stb     %3, (%1, 0)     \n"             \
 357         "       addi    %2,  1          \n"             \
 358         "       addi    %1,  1          \n"             \
 359         "       subi    %0,  1          \n"             \
 360         "       br      5b              \n"             \
 361         "8:     stw     %3, (%1, 0)     \n"             \
 362         "       subi    %0, 4           \n"             \
 363         "       bf      7f              \n"             \
 364         "9:     subi    %0, 8           \n"             \
 365         "       bf      7f              \n"             \
 366         "13:    stw     %3, (%1, 8)     \n"             \
 367         "       subi    %0, 12          \n"             \
 368         "       bf      7f              \n"             \
 369         ".section __ex_table, \"a\"     \n"             \
 370         ".align   2                     \n"             \
 371         ".long    2b, 7f                \n"             \
 372         ".long    4b, 7f                \n"             \
 373         ".long    6b, 7f                \n"             \
 374         ".long   10b, 8b                \n"             \
 375         ".long   11b, 9b                \n"             \
 376         ".long   12b,13b                \n"             \
 377         ".previous                      \n"             \
 378         "7:                             \n"             \
 379         : "=r"(n), "=r"(to), "=r"(from), "=r"(nsave),   \
 380           "=r"(tmp)                                     \
 381         : "0"(n), "1"(to), "2"(from)                    \
 382         : "memory");                                    \
 383 } while (0)
 384
 385 unsigned long raw_copy_from_user(void *to, const void *from, unsigned long n);
 386 unsigned long raw_copy_to_user(void *to, const void *from, unsigned long n);
 387
 388 unsigned long clear_user(void *to, unsigned long n);
 389 unsigned long __clear_user(void __user *to, unsigned long n);
 390
 391 long strncpy_from_user(char *dst, const char *src, long count);
 392 long __strncpy_from_user(char *dst, const char *src, long count);
 393
 394 /*
 395  * Return the size of a string (including the ending 0)
 396  *
 397  * Return 0 on exception, a value greater than N if too long
 398  */
 399 long strnlen_user(const char *src, long n);
 400
 401 #define strlen_user(str) strnlen_user(str, 32767)
 402
 403 struct exception_table_entry {
 404         unsigned long insn;
 405         unsigned long nextinsn;
 406 };
 407
 408 extern int fixup_exception(struct pt_regs *regs);
 409
 410 #endif /* __ASM_CSKY_UACCESS_H */