include/asm-m32r/uaccess.h

   1 #ifndef _ASM_M32R_UACCESS_H
   2 #define _ASM_M32R_UACCESS_H
   3
   4 /*
   5  *  linux/include/asm-m32r/uaccess.h
   6  *
   7  *  M32R version.
   8  *    Copyright (C) 2004  Hirokazu Takata <takata at linux-m32r.org>
   9  */
  10
  11 #undef UACCESS_DEBUG
  12
  13 #ifdef UACCESS_DEBUG
  14 #define UAPRINTK(args...) printk(args)
  15 #else
  16 #define UAPRINTK(args...)
  17 #endif /* UACCESS_DEBUG */
  18
  19 /*
  20  * User space memory access functions
  21  */
  22 #include <linux/config.h>
  23 #include <linux/errno.h>
  24 #include <linux/thread_info.h>
  25 #include <asm/page.h>
  26
  27 #define VERIFY_READ 0
  28 #define VERIFY_WRITE 1
  29
  30 /*
  31  * The fs value determines whether argument validity checking should be
  32  * performed or not.  If get_fs() == USER_DS, checking is performed, with
  33  * get_fs() == KERNEL_DS, checking is bypassed.
  34  *
  35  * For historical reasons, these macros are grossly misnamed.
  36  */
  37
  38 #define MAKE_MM_SEG(s)  ((mm_segment_t) { (s) })
  39
  40 #ifdef CONFIG_MMU
  41 #define KERNEL_DS       MAKE_MM_SEG(0xFFFFFFFF)
  42 #define USER_DS         MAKE_MM_SEG(PAGE_OFFSET)
  43 #else
  44 #define KERNEL_DS       MAKE_MM_SEG(0xFFFFFFFF)
  45 #define USER_DS         MAKE_MM_SEG(0xFFFFFFFF)
  46 #endif /* CONFIG_MMU */
  47
  48 #define get_ds()        (KERNEL_DS)
  49 #ifdef CONFIG_MMU
  50 #define get_fs()        (current_thread_info()->addr_limit)
  51 #define set_fs(x)       (current_thread_info()->addr_limit = (x))
  52 #else
  53 static inline mm_segment_t get_fs(void)
  54 {
  55   return USER_DS;
  56 }
  57
  58 static inline void set_fs(mm_segment_t s)
  59 {
  60 }
  61 #endif /* CONFIG_MMU */
  62
  63 #define segment_eq(a,b) ((a).seg == (b).seg)
  64
  65 #define __addr_ok(addr) \
  66         ((unsigned long)(addr) < (current_thread_info()->addr_limit.seg))
  67
  68 /*
  69  * Test whether a block of memory is a valid user space address.
  70  * Returns 0 if the range is valid, nonzero otherwise.
  71  *
  72  * This is equivalent to the following test:
  73  * (u33)addr + (u33)size >= (u33)current->addr_limit.seg
  74  *
  75  * This needs 33-bit arithmetic. We have a carry...
  76  */
  77 #define __range_ok(addr,size) ({                                        \
  78         unsigned long flag, sum;                                        \
  79         __chk_user_ptr(addr);                                           \
  80         asm (                                                           \
  81                 "       cmpu    %1, %1    ; clear cbit\n"               \
  82                 "       addx    %1, %3    ; set cbit if overflow\n"     \
  83                 "       subx    %0, %0\n"                               \
  84                 "       cmpu    %4, %1\n"                               \
  85                 "       subx    %0, %5\n"                               \
  86                 : "=&r"(flag), "=r"(sum)                                \
  87                 : "1"(addr), "r"((int)(size)),                          \
  88                   "r"(current_thread_info()->addr_limit.seg), "r"(0)    \
  89                 : "cbit" );                                             \
  90         flag; })
  91
  92 /**
  93  * access_ok: - Checks if a user space pointer is valid
  94  * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
  95  *        %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
  96  *        to write to a block, it is always safe to read from it.
  97  * @addr: User space pointer to start of block to check
  98  * @size: Size of block to check
  99  *
 100  * Context: User context only.  This function may sleep.
 101  *
 102  * Checks if a pointer to a block of memory in user space is valid.
 103  *
 104  * Returns true (nonzero) if the memory block may be valid, false (zero)
 105  * if it is definitely invalid.
 106  *
 107  * Note that, depending on architecture, this function probably just
 108  * checks that the pointer is in the user space range - after calling
 109  * this function, memory access functions may still return -EFAULT.
 110  */
 111 #ifdef CONFIG_MMU
 112 #define access_ok(type,addr,size) (likely(__range_ok(addr,size) == 0))
 113 #else
 114 static inline int access_ok(int type, const void *addr, unsigned long size)
 115 {
 116   extern unsigned long memory_start, memory_end;
 117   unsigned long val = (unsigned long)addr;
 118
 119   return ((val >= memory_start) && ((val + size) < memory_end));
 120 }
 121 #endif /* CONFIG_MMU */
 122
 123 /*
 124  * The exception table consists of pairs of addresses: the first is the
 125  * address of an instruction that is allowed to fault, and the second is
 126  * the address at which the program should continue.  No registers are
 127  * modified, so it is entirely up to the continuation code to figure out
 128  * what to do.
 129  *
 130  * All the routines below use bits of fixup code that are out of line
 131  * with the main instruction path.  This means when everything is well,
 132  * we don't even have to jump over them.  Further, they do not intrude
 133  * on our cache or tlb entries.
 134  */
 135
 136 struct exception_table_entry
 137 {
 138         unsigned long insn, fixup;
 139 };
 140
 141 extern int fixup_exception(struct pt_regs *regs);
 142
 143 /*
 144  * These are the main single-value transfer routines.  They automatically
 145  * use the right size if we just have the right pointer type.
 146  *
 147  * This gets kind of ugly. We want to return _two_ values in "get_user()"
 148  * and yet we don't want to do any pointers, because that is too much
 149  * of a performance impact. Thus we have a few rather ugly macros here,
 150  * and hide all the uglyness from the user.
 151  *
 152  * The "__xxx" versions of the user access functions are versions that
 153  * do not verify the address space, that must have been done previously
 154  * with a separate "access_ok()" call (this is used when we do multiple
 155  * accesses to the same area of user memory).
 156  */
 157
 158 extern void __get_user_1(void);
 159 extern void __get_user_2(void);
 160 extern void __get_user_4(void);
 161
 162 #ifndef MODULE
 163 #define __get_user_x(size,ret,x,ptr)                                    \
 164         __asm__ __volatile__(                                           \
 165                 "       mv      r0, %0\n"                               \
 166                 "       mv      r1, %1\n"                               \
 167                 "       bl __get_user_" #size "\n"                      \
 168                 "       mv      %0, r0\n"                               \
 169                 "       mv      %1, r1\n"                               \
 170                 : "=r"(ret), "=r"(x)                                    \
 171                 : "0"(ptr)                                              \
 172                 : "r0", "r1", "r14" )
 173 #else /* MODULE */
 174 /*
 175  * Use "jl" instead of "bl" for MODULE
 176  */
 177 #define __get_user_x(size,ret,x,ptr)                                    \
 178         __asm__ __volatile__(                                           \
 179                 "       mv      r0, %0\n"                               \
 180                 "       mv      r1, %1\n"                               \
 181                 "       seth    lr, #high(__get_user_" #size ")\n"      \
 182                 "       or3     lr, lr, #low(__get_user_" #size ")\n"   \
 183                 "       jl      lr\n"                                   \
 184                 "       mv      %0, r0\n"                               \
 185                 "       mv      %1, r1\n"                               \
 186                 : "=r"(ret), "=r"(x)                                    \
 187                 : "0"(ptr)                                              \
 188                 : "r0", "r1", "r14" )
 189 #endif
 190
 191 /* Careful: we have to cast the result to the type of the pointer for sign
 192    reasons */
 193 /**
 194  * get_user: - Get a simple variable from user space.
 195  * @x:   Variable to store result.
 196  * @ptr: Source address, in user space.
 197  *
 198  * Context: User context only.  This function may sleep.
 199  *
 200  * This macro copies a single simple variable from user space to kernel
 201  * space.  It supports simple types like char and int, but not larger
 202  * data types like structures or arrays.
 203  *
 204  * @ptr must have pointer-to-simple-variable type, and the result of
 205  * dereferencing @ptr must be assignable to @x without a cast.
 206  *
 207  * Returns zero on success, or -EFAULT on error.
 208  * On error, the variable @x is set to zero.
 209  */
 210 #define get_user(x,ptr)                                                 \
 211 ({      int __ret_gu,__val_gu;                                          \
 212         __chk_user_ptr(ptr);                                            \
 213         switch(sizeof (*(ptr))) {                                       \
 214         case 1:  __get_user_x(1,__ret_gu,__val_gu,ptr); break;          \
 215         case 2:  __get_user_x(2,__ret_gu,__val_gu,ptr); break;          \
 216         case 4:  __get_user_x(4,__ret_gu,__val_gu,ptr); break;          \
 217         default: __get_user_x(X,__ret_gu,__val_gu,ptr); break;          \
 218         }                                                               \
 219         (x) = (__typeof__(*(ptr)))__val_gu;                             \
 220         __ret_gu;                                                       \
 221 })
 222
 223 extern void __put_user_bad(void);
 224
 225 /**
 226  * put_user: - Write a simple value into user space.
 227  * @x:   Value to copy to user space.
 228  * @ptr: Destination address, in user space.
 229  *
 230  * Context: User context only.  This function may sleep.
 231  *
 232  * This macro copies a single simple value from kernel space to user
 233  * space.  It supports simple types like char and int, but not larger
 234  * data types like structures or arrays.
 235  *
 236  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 237  * to the result of dereferencing @ptr.
 238  *
 239  * Returns zero on success, or -EFAULT on error.
 240  */
 241 #define put_user(x,ptr)                                                 \
 242   __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
 243
 244
 245 /**
 246  * __get_user: - Get a simple variable from user space, with less checking.
 247  * @x:   Variable to store result.
 248  * @ptr: Source address, in user space.
 249  *
 250  * Context: User context only.  This function may sleep.
 251  *
 252  * This macro copies a single simple variable from user space to kernel
 253  * space.  It supports simple types like char and int, but not larger
 254  * data types like structures or arrays.
 255  *
 256  * @ptr must have pointer-to-simple-variable type, and the result of
 257  * dereferencing @ptr must be assignable to @x without a cast.
 258  *
 259  * Caller must check the pointer with access_ok() before calling this
 260  * function.
 261  *
 262  * Returns zero on success, or -EFAULT on error.
 263  * On error, the variable @x is set to zero.
 264  */
 265 #define __get_user(x,ptr) \
 266   __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
 267
 268
 269 /**
 270  * __put_user: - Write a simple value into user space, with less checking.
 271  * @x:   Value to copy to user space.
 272  * @ptr: Destination address, in user space.
 273  *
 274  * Context: User context only.  This function may sleep.
 275  *
 276  * This macro copies a single simple value from kernel space to user
 277  * space.  It supports simple types like char and int, but not larger
 278  * data types like structures or arrays.
 279  *
 280  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 281  * to the result of dereferencing @ptr.
 282  *
 283  * Caller must check the pointer with access_ok() before calling this
 284  * function.
 285  *
 286  * Returns zero on success, or -EFAULT on error.
 287  */
 288 #define __put_user(x,ptr) \
 289   __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
 290
 291 #define __put_user_nocheck(x,ptr,size)                                  \
 292 ({                                                                      \
 293         long __pu_err;                                                  \
 294         __put_user_size((x),(ptr),(size),__pu_err);                     \
 295         __pu_err;                                                       \
 296 })
 297
 298
 299 #define __put_user_check(x,ptr,size)                                    \
 300 ({                                                                      \
 301         long __pu_err = -EFAULT;                                        \
 302         __typeof__(*(ptr)) __user *__pu_addr = (ptr);                   \
 303         might_sleep();                                                  \
 304         if (access_ok(VERIFY_WRITE,__pu_addr,size))                     \
 305                 __put_user_size((x),__pu_addr,(size),__pu_err);         \
 306         __pu_err;                                                       \
 307 })
 308
 309 #if defined(__LITTLE_ENDIAN__)
 310 #define __put_user_u64(x, addr, err)                                    \
 311         __asm__ __volatile__(                                           \
 312                 "       .fillinsn\n"                                    \
 313                 "1:     st %L1,@%2\n"                                    \
 314                 "       .fillinsn\n"                                    \
 315                 "2:     st %H1,@(4,%2)\n"                                \
 316                 "       .fillinsn\n"                                    \
 317                 "3:\n"                                                  \
 318                 ".section .fixup,\"ax\"\n"                              \
 319                 "       .balign 4\n"                                    \
 320                 "4:     ldi %0,%3\n"                                    \
 321                 "       seth r14,#high(3b)\n"                           \
 322                 "       or3 r14,r14,#low(3b)\n"                         \
 323                 "       jmp r14\n"                                      \
 324                 ".previous\n"                                           \
 325                 ".section __ex_table,\"a\"\n"                           \
 326                 "       .balign 4\n"                                    \
 327                 "       .long 1b,4b\n"                                  \
 328                 "       .long 2b,4b\n"                                  \
 329                 ".previous"                                             \
 330                 : "=r"(err)                                             \
 331                 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err)             \
 332                 : "r14", "memory")
 333
 334 #elif defined(__BIG_ENDIAN__)
 335 #define __put_user_u64(x, addr, err)                                    \
 336         __asm__ __volatile__(                                           \
 337                 "       .fillinsn\n"                                    \
 338                 "1:     st %H1,@%2\n"                                   \
 339                 "       .fillinsn\n"                                    \
 340                 "2:     st %L1,@(4,%2)\n"                               \
 341                 "       .fillinsn\n"                                    \
 342                 "3:\n"                                                  \
 343                 ".section .fixup,\"ax\"\n"                              \
 344                 "       .balign 4\n"                                    \
 345                 "4:     ldi %0,%3\n"                                    \
 346                 "       seth r14,#high(3b)\n"                           \
 347                 "       or3 r14,r14,#low(3b)\n"                         \
 348                 "       jmp r14\n"                                      \
 349                 ".previous\n"                                           \
 350                 ".section __ex_table,\"a\"\n"                           \
 351                 "       .balign 4\n"                                    \
 352                 "       .long 1b,4b\n"                                  \
 353                 "       .long 2b,4b\n"                                  \
 354                 ".previous"                                             \
 355                 : "=r"(err)                                             \
 356                 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err)             \
 357                 : "r14", "memory")
 358 #else
 359 #error no endian defined
 360 #endif
 361
 362 #define __put_user_size(x,ptr,size,retval)                              \
 363 do {                                                                    \
 364         retval = 0;                                                     \
 365         __chk_user_ptr(ptr);                                            \
 366         switch (size) {                                                 \
 367           case 1: __put_user_asm(x,ptr,retval,"b"); break;              \
 368           case 2: __put_user_asm(x,ptr,retval,"h"); break;              \
 369           case 4: __put_user_asm(x,ptr,retval,""); break;               \
 370           case 8: __put_user_u64((__typeof__(*ptr))(x),ptr,retval); break;\
 371           default: __put_user_bad();                                    \
 372         }                                                               \
 373 } while (0)
 374
 375 struct __large_struct { unsigned long buf[100]; };
 376 #define __m(x) (*(struct __large_struct *)(x))
 377
 378 /*
 379  * Tell gcc we read from memory instead of writing: this is because
 380  * we do not write to any memory gcc knows about, so there are no
 381  * aliasing issues.
 382  */
 383 #define __put_user_asm(x, addr, err, itype)                             \
 384         __asm__ __volatile__(                                           \
 385                 "       .fillinsn\n"                                    \
 386                 "1:     st"itype" %1,@%2\n"                             \
 387                 "       .fillinsn\n"                                    \
 388                 "2:\n"                                                  \
 389                 ".section .fixup,\"ax\"\n"                              \
 390                 "       .balign 4\n"                                    \
 391                 "3:     ldi %0,%3\n"                                    \
 392                 "       seth r14,#high(2b)\n"                           \
 393                 "       or3 r14,r14,#low(2b)\n"                         \
 394                 "       jmp r14\n"                                      \
 395                 ".previous\n"                                           \
 396                 ".section __ex_table,\"a\"\n"                           \
 397                 "       .balign 4\n"                                    \
 398                 "       .long 1b,3b\n"                                  \
 399                 ".previous"                                             \
 400                 : "=r"(err)                                             \
 401                 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err)             \
 402                 : "r14", "memory")
 403
 404 #define __get_user_nocheck(x,ptr,size)                                  \
 405 ({                                                                      \
 406         long __gu_err, __gu_val;                                        \
 407         __get_user_size(__gu_val,(ptr),(size),__gu_err);                \
 408         (x) = (__typeof__(*(ptr)))__gu_val;                             \
 409         __gu_err;                                                       \
 410 })
 411
 412 extern long __get_user_bad(void);
 413
 414 #define __get_user_size(x,ptr,size,retval)                              \
 415 do {                                                                    \
 416         retval = 0;                                                     \
 417         __chk_user_ptr(ptr);                                            \
 418         switch (size) {                                                 \
 419           case 1: __get_user_asm(x,ptr,retval,"ub"); break;             \
 420           case 2: __get_user_asm(x,ptr,retval,"uh"); break;             \
 421           case 4: __get_user_asm(x,ptr,retval,""); break;               \
 422           default: (x) = __get_user_bad();                              \
 423         }                                                               \
 424 } while (0)
 425
 426 #define __get_user_asm(x, addr, err, itype)                             \
 427         __asm__ __volatile__(                                           \
 428                 "       .fillinsn\n"                                    \
 429                 "1:     ld"itype" %1,@%2\n"                             \
 430                 "       .fillinsn\n"                                    \
 431                 "2:\n"                                                  \
 432                 ".section .fixup,\"ax\"\n"                              \
 433                 "       .balign 4\n"                                    \
 434                 "3:     ldi %0,%3\n"                                    \
 435                 "       seth r14,#high(2b)\n"                           \
 436                 "       or3 r14,r14,#low(2b)\n"                         \
 437                 "       jmp r14\n"                                      \
 438                 ".previous\n"                                           \
 439                 ".section __ex_table,\"a\"\n"                           \
 440                 "       .balign 4\n"                                    \
 441                 "       .long 1b,3b\n"                                  \
 442                 ".previous"                                             \
 443                 : "=r"(err), "=&r"(x)                                   \
 444                 : "r"(addr), "i"(-EFAULT), "0"(err)                     \
 445                 : "r14", "memory")
 446
 447 /*
 448  * Here we special-case 1, 2 and 4-byte copy_*_user invocations.  On a fault
 449  * we return the initial request size (1, 2 or 4), as copy_*_user should do.
 450  * If a store crosses a page boundary and gets a fault, the m32r will not write
 451  * anything, so this is accurate.
 452  */
 453
 454
 455 /*
 456  * Copy To/From Userspace
 457  */
 458
 459 /* Generic arbitrary sized copy.  */
 460 /* Return the number of bytes NOT copied.  */
 461 #define __copy_user(to,from,size)                                       \
 462 do {                                                                    \
 463         unsigned long __dst, __src, __c;                                \
 464         __asm__ __volatile__ (                                          \
 465                 "       mv      r14, %0\n"                              \
 466                 "       or      r14, %1\n"                              \
 467                 "       beq     %0, %1, 9f\n"                           \
 468                 "       beqz    %2, 9f\n"                               \
 469                 "       and3    r14, r14, #3\n"                         \
 470                 "       bnez    r14, 2f\n"                              \
 471                 "       and3    %2, %2, #3\n"                           \
 472                 "       beqz    %3, 2f\n"                               \
 473                 "       addi    %0, #-4         ; word_copy \n"         \
 474                 "       .fillinsn\n"                                    \
 475                 "0:     ld      r14, @%1+\n"                            \
 476                 "       addi    %3, #-1\n"                              \
 477                 "       .fillinsn\n"                                    \
 478                 "1:     st      r14, @+%0\n"                            \
 479                 "       bnez    %3, 0b\n"                               \
 480                 "       beqz    %2, 9f\n"                               \
 481                 "       addi    %0, #4\n"                               \
 482                 "       .fillinsn\n"                                    \
 483                 "2:     ldb     r14, @%1        ; byte_copy \n"         \
 484                 "       .fillinsn\n"                                    \
 485                 "3:     stb     r14, @%0\n"                             \
 486                 "       addi    %1, #1\n"                               \
 487                 "       addi    %2, #-1\n"                              \
 488                 "       addi    %0, #1\n"                               \
 489                 "       bnez    %2, 2b\n"                               \
 490                 "       .fillinsn\n"                                    \
 491                 "9:\n"                                                  \
 492                 ".section .fixup,\"ax\"\n"                              \
 493                 "       .balign 4\n"                                    \
 494                 "5:     addi    %3, #1\n"                               \
 495                 "       addi    %1, #-4\n"                              \
 496                 "       .fillinsn\n"                                    \
 497                 "6:     slli    %3, #2\n"                               \
 498                 "       add     %2, %3\n"                               \
 499                 "       addi    %0, #4\n"                               \
 500                 "       .fillinsn\n"                                    \
 501                 "7:     seth    r14, #high(9b)\n"                       \
 502                 "       or3     r14, r14, #low(9b)\n"                   \
 503                 "       jmp     r14\n"                                  \
 504                 ".previous\n"                                           \
 505                 ".section __ex_table,\"a\"\n"                           \
 506                 "       .balign 4\n"                                    \
 507                 "       .long 0b,6b\n"                                  \
 508                 "       .long 1b,5b\n"                                  \
 509                 "       .long 2b,9b\n"                                  \
 510                 "       .long 3b,9b\n"                                  \
 511                 ".previous\n"                                           \
 512                 : "=&r"(__dst), "=&r"(__src), "=&r"(size), "=&r"(__c)   \
 513                 : "0"(to), "1"(from), "2"(size), "3"(size / 4)          \
 514                 : "r14", "memory");                                     \
 515 } while (0)
 516
 517 #define __copy_user_zeroing(to,from,size)                               \
 518 do {                                                                    \
 519         unsigned long __dst, __src, __c;                                \
 520         __asm__ __volatile__ (                                          \
 521                 "       mv      r14, %0\n"                              \
 522                 "       or      r14, %1\n"                              \
 523                 "       beq     %0, %1, 9f\n"                           \
 524                 "       beqz    %2, 9f\n"                               \
 525                 "       and3    r14, r14, #3\n"                         \
 526                 "       bnez    r14, 2f\n"                              \
 527                 "       and3    %2, %2, #3\n"                           \
 528                 "       beqz    %3, 2f\n"                               \
 529                 "       addi    %0, #-4         ; word_copy \n"         \
 530                 "       .fillinsn\n"                                    \
 531                 "0:     ld      r14, @%1+\n"                            \
 532                 "       addi    %3, #-1\n"                              \
 533                 "       .fillinsn\n"                                    \
 534                 "1:     st      r14, @+%0\n"                            \
 535                 "       bnez    %3, 0b\n"                               \
 536                 "       beqz    %2, 9f\n"                               \
 537                 "       addi    %0, #4\n"                               \
 538                 "       .fillinsn\n"                                    \
 539                 "2:     ldb     r14, @%1        ; byte_copy \n"         \
 540                 "       .fillinsn\n"                                    \
 541                 "3:     stb     r14, @%0\n"                             \
 542                 "       addi    %1, #1\n"                               \
 543                 "       addi    %2, #-1\n"                              \
 544                 "       addi    %0, #1\n"                               \
 545                 "       bnez    %2, 2b\n"                               \
 546                 "       .fillinsn\n"                                    \
 547                 "9:\n"                                                  \
 548                 ".section .fixup,\"ax\"\n"                              \
 549                 "       .balign 4\n"                                    \
 550                 "5:     addi    %3, #1\n"                               \
 551                 "       addi    %1, #-4\n"                              \
 552                 "       .fillinsn\n"                                    \
 553                 "6:     slli    %3, #2\n"                               \
 554                 "       add     %2, %3\n"                               \
 555                 "       addi    %0, #4\n"                               \
 556                 "       .fillinsn\n"                                    \
 557                 "7:     ldi     r14, #0         ; store zero \n"        \
 558                 "       .fillinsn\n"                                    \
 559                 "8:     addi    %2, #-1\n"                              \
 560                 "       stb     r14, @%0        ; ACE? \n"              \
 561                 "       addi    %0, #1\n"                               \
 562                 "       bnez    %2, 8b\n"                               \
 563                 "       seth    r14, #high(9b)\n"                       \
 564                 "       or3     r14, r14, #low(9b)\n"                   \
 565                 "       jmp     r14\n"                                  \
 566                 ".previous\n"                                           \
 567                 ".section __ex_table,\"a\"\n"                           \
 568                 "       .balign 4\n"                                    \
 569                 "       .long 0b,6b\n"                                  \
 570                 "       .long 1b,5b\n"                                  \
 571                 "       .long 2b,7b\n"                                  \
 572                 "       .long 3b,7b\n"                                  \
 573                 ".previous\n"                                           \
 574                 : "=&r"(__dst), "=&r"(__src), "=&r"(size), "=&r"(__c)   \
 575                 : "0"(to), "1"(from), "2"(size), "3"(size / 4)          \
 576                 : "r14", "memory");                                     \
 577 } while (0)
 578
 579
 580 /* We let the __ versions of copy_from/to_user inline, because they're often
 581  * used in fast paths and have only a small space overhead.
 582  */
 583 static inline unsigned long __generic_copy_from_user_nocheck(void *to,
 584         const void __user *from, unsigned long n)
 585 {
 586         __copy_user_zeroing(to,from,n);
 587         return n;
 588 }
 589
 590 static inline unsigned long __generic_copy_to_user_nocheck(void __user *to,
 591         const void *from, unsigned long n)
 592 {
 593         __copy_user(to,from,n);
 594         return n;
 595 }
 596
 597 unsigned long __generic_copy_to_user(void *, const void *, unsigned long);
 598 unsigned long __generic_copy_from_user(void *, const void *, unsigned long);
 599
 600 /**
 601  * __copy_to_user: - Copy a block of data into user space, with less checking.
 602  * @to:   Destination address, in user space.
 603  * @from: Source address, in kernel space.
 604  * @n:    Number of bytes to copy.
 605  *
 606  * Context: User context only.  This function may sleep.
 607  *
 608  * Copy data from kernel space to user space.  Caller must check
 609  * the specified block with access_ok() before calling this function.
 610  *
 611  * Returns number of bytes that could not be copied.
 612  * On success, this will be zero.
 613  */
 614 #define __copy_to_user(to,from,n)                       \
 615         __generic_copy_to_user_nocheck((to),(from),(n))
 616
 617 #define __copy_to_user_inatomic __copy_to_user
 618 #define __copy_from_user_inatomic __copy_from_user
 619
 620 /**
 621  * copy_to_user: - Copy a block of data into user space.
 622  * @to:   Destination address, in user space.
 623  * @from: Source address, in kernel space.
 624  * @n:    Number of bytes to copy.
 625  *
 626  * Context: User context only.  This function may sleep.
 627  *
 628  * Copy data from kernel space to user space.
 629  *
 630  * Returns number of bytes that could not be copied.
 631  * On success, this will be zero.
 632  */
 633 #define copy_to_user(to,from,n)                         \
 634 ({                                                      \
 635         might_sleep();                                  \
 636         __generic_copy_to_user((to),(from),(n));        \
 637 })
 638
 639 /**
 640  * __copy_from_user: - Copy a block of data from user space, with less checking. * @to:   Destination address, in kernel space.
 641  * @from: Source address, in user space.
 642  * @n:    Number of bytes to copy.
 643  *
 644  * Context: User context only.  This function may sleep.
 645  *
 646  * Copy data from user space to kernel space.  Caller must check
 647  * the specified block with access_ok() before calling this function.
 648  *
 649  * Returns number of bytes that could not be copied.
 650  * On success, this will be zero.
 651  *
 652  * If some data could not be copied, this function will pad the copied
 653  * data to the requested size using zero bytes.
 654  */
 655 #define __copy_from_user(to,from,n)                     \
 656         __generic_copy_from_user_nocheck((to),(from),(n))
 657
 658 /**
 659  * copy_from_user: - Copy a block of data from user space.
 660  * @to:   Destination address, in kernel space.
 661  * @from: Source address, in user space.
 662  * @n:    Number of bytes to copy.
 663  *
 664  * Context: User context only.  This function may sleep.
 665  *
 666  * Copy data from user space to kernel space.
 667  *
 668  * Returns number of bytes that could not be copied.
 669  * On success, this will be zero.
 670  *
 671  * If some data could not be copied, this function will pad the copied
 672  * data to the requested size using zero bytes.
 673  */
 674 #define copy_from_user(to,from,n)                       \
 675 ({                                                      \
 676         might_sleep();                                  \
 677 __generic_copy_from_user((to),(from),(n));      \
 678 })
 679
 680 long __must_check strncpy_from_user(char *dst, const char __user *src,
 681                                 long count);
 682 long __must_check __strncpy_from_user(char *dst,
 683                                 const char __user *src, long count);
 684
 685 /**
 686  * __clear_user: - Zero a block of memory in user space, with less checking.
 687  * @to:   Destination address, in user space.
 688  * @n:    Number of bytes to zero.
 689  *
 690  * Zero a block of memory in user space.  Caller must check
 691  * the specified block with access_ok() before calling this function.
 692  *
 693  * Returns number of bytes that could not be cleared.
 694  * On success, this will be zero.
 695  */
 696 unsigned long __clear_user(void __user *mem, unsigned long len);
 697
 698 /**
 699  * clear_user: - Zero a block of memory in user space.
 700  * @to:   Destination address, in user space.
 701  * @n:    Number of bytes to zero.
 702  *
 703  * Zero a block of memory in user space.  Caller must check
 704  * the specified block with access_ok() before calling this function.
 705  *
 706  * Returns number of bytes that could not be cleared.
 707  * On success, this will be zero.
 708  */
 709 unsigned long clear_user(void __user *mem, unsigned long len);
 710
 711 /**
 712  * strlen_user: - Get the size of a string in user space.
 713  * @str: The string to measure.
 714  *
 715  * Context: User context only.  This function may sleep.
 716  *
 717  * Get the size of a NUL-terminated string in user space.
 718  *
 719  * Returns the size of the string INCLUDING the terminating NUL.
 720  * On exception, returns 0.
 721  *
 722  * If there is a limit on the length of a valid string, you may wish to
 723  * consider using strnlen_user() instead.
 724  */
 725 #define strlen_user(str) strnlen_user(str, ~0UL >> 1)
 726 long strnlen_user(const char __user *str, long n);
 727
 728 #endif /* _ASM_M32R_UACCESS_H */