arch/mips/include/asm/uaccess.h

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1996, 1997, 1998, 1999, 2000, 03, 04 by Ralf Baechle
   7  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
   8  * Copyright (C) 2007  Maciej W. Rozycki
   9  * Copyright (C) 2014, Imagination Technologies Ltd.
  10  */
  11 #ifndef _ASM_UACCESS_H
  12 #define _ASM_UACCESS_H
  13
  14 #include <linux/kernel.h>
  15 #include <linux/errno.h>
  16 #include <linux/thread_info.h>
  17 #include <asm/asm-eva.h>
  18
  19 /*
  20  * The fs value determines whether argument validity checking should be
  21  * performed or not.  If get_fs() == USER_DS, checking is performed, with
  22  * get_fs() == KERNEL_DS, checking is bypassed.
  23  *
  24  * For historical reasons, these macros are grossly misnamed.
  25  */
  26 #ifdef CONFIG_32BIT
  27
  28 #ifdef CONFIG_KVM_GUEST
  29 #define __UA_LIMIT 0x40000000UL
  30 #else
  31 #define __UA_LIMIT 0x80000000UL
  32 #endif
  33
  34 #define __UA_ADDR       ".word"
  35 #define __UA_LA         "la"
  36 #define __UA_ADDU       "addu"
  37 #define __UA_t0         "$8"
  38 #define __UA_t1         "$9"
  39
  40 #endif /* CONFIG_32BIT */
  41
  42 #ifdef CONFIG_64BIT
  43
  44 extern u64 __ua_limit;
  45
  46 #define __UA_LIMIT      __ua_limit
  47
  48 #define __UA_ADDR       ".dword"
  49 #define __UA_LA         "dla"
  50 #define __UA_ADDU       "daddu"
  51 #define __UA_t0         "$12"
  52 #define __UA_t1         "$13"
  53
  54 #endif /* CONFIG_64BIT */
  55
  56 /*
  57  * USER_DS is a bitmask that has the bits set that may not be set in a valid
  58  * userspace address.  Note that we limit 32-bit userspace to 0x7fff8000 but
  59  * the arithmetic we're doing only works if the limit is a power of two, so
  60  * we use 0x80000000 here on 32-bit kernels.  If a process passes an invalid
  61  * address in this range it's the process's problem, not ours :-)
  62  */
  63
  64 #ifdef CONFIG_KVM_GUEST
  65 #define KERNEL_DS       ((mm_segment_t) { 0x80000000UL })
  66 #define USER_DS         ((mm_segment_t) { 0xC0000000UL })
  67 #else
  68 #define KERNEL_DS       ((mm_segment_t) { 0UL })
  69 #define USER_DS         ((mm_segment_t) { __UA_LIMIT })
  70 #endif
  71
  72 #define VERIFY_READ    0
  73 #define VERIFY_WRITE   1
  74
  75 #define get_ds()        (KERNEL_DS)
  76 #define get_fs()        (current_thread_info()->addr_limit)
  77 #define set_fs(x)       (current_thread_info()->addr_limit = (x))
  78
  79 #define segment_eq(a, b)        ((a).seg == (b).seg)
  80
  81 /*
  82  * eva_kernel_access() - determine whether kernel memory access on an EVA system
  83  *
  84  * Determines whether memory accesses should be performed to kernel memory
  85  * on a system using Extended Virtual Addressing (EVA).
  86  *
  87  * Return: true if a kernel memory access on an EVA system, else false.
  88  */
  89 static inline bool eva_kernel_access(void)
  90 {
  91         if (!IS_ENABLED(CONFIG_EVA))
  92                 return false;
  93
  94         return segment_eq(get_fs(), get_ds());
  95 }
  96
  97 /*
  98  * Is a address valid? This does a straightforward calculation rather
  99  * than tests.
 100  *
 101  * Address valid if:
 102  *  - "addr" doesn't have any high-bits set
 103  *  - AND "size" doesn't have any high-bits set
 104  *  - AND "addr+size" doesn't have any high-bits set
 105  *  - OR we are in kernel mode.
 106  *
 107  * __ua_size() is a trick to avoid runtime checking of positive constant
 108  * sizes; for those we already know at compile time that the size is ok.
 109  */
 110 #define __ua_size(size)                                                 \
 111         ((__builtin_constant_p(size) && (signed long) (size) > 0) ? 0 : (size))
 112
 113 /*
 114  * access_ok: - Checks if a user space pointer is valid
 115  * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
 116  *        %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
 117  *        to write to a block, it is always safe to read from it.
 118  * @addr: User space pointer to start of block to check
 119  * @size: Size of block to check
 120  *
 121  * Context: User context only. This function may sleep if pagefaults are
 122  *          enabled.
 123  *
 124  * Checks if a pointer to a block of memory in user space is valid.
 125  *
 126  * Returns true (nonzero) if the memory block may be valid, false (zero)
 127  * if it is definitely invalid.
 128  *
 129  * Note that, depending on architecture, this function probably just
 130  * checks that the pointer is in the user space range - after calling
 131  * this function, memory access functions may still return -EFAULT.
 132  */
 133
 134 #define __access_mask get_fs().seg
 135
 136 #define __access_ok(addr, size, mask)                                   \
 137 ({                                                                      \
 138         unsigned long __addr = (unsigned long) (addr);                  \
 139         unsigned long __size = size;                                    \
 140         unsigned long __mask = mask;                                    \
 141         unsigned long __ok;                                             \
 142                                                                         \
 143         __chk_user_ptr(addr);                                           \
 144         __ok = (signed long)(__mask & (__addr | (__addr + __size) |     \
 145                 __ua_size(__size)));                                    \
 146         __ok == 0;                                                      \
 147 })
 148
 149 #define access_ok(type, addr, size)                                     \
 150         likely(__access_ok((addr), (size), __access_mask))
 151
 152 /*
 153  * put_user: - Write a simple value into user space.
 154  * @x:   Value to copy to user space.
 155  * @ptr: Destination address, in user space.
 156  *
 157  * Context: User context only. This function may sleep if pagefaults are
 158  *          enabled.
 159  *
 160  * This macro copies a single simple value from kernel space to user
 161  * space.  It supports simple types like char and int, but not larger
 162  * data types like structures or arrays.
 163  *
 164  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 165  * to the result of dereferencing @ptr.
 166  *
 167  * Returns zero on success, or -EFAULT on error.
 168  */
 169 #define put_user(x,ptr) \
 170         __put_user_check((x), (ptr), sizeof(*(ptr)))
 171
 172 /*
 173  * get_user: - Get a simple variable from user space.
 174  * @x:   Variable to store result.
 175  * @ptr: Source address, in user space.
 176  *
 177  * Context: User context only. This function may sleep if pagefaults are
 178  *          enabled.
 179  *
 180  * This macro copies a single simple variable from user space to kernel
 181  * space.  It supports simple types like char and int, but not larger
 182  * data types like structures or arrays.
 183  *
 184  * @ptr must have pointer-to-simple-variable type, and the result of
 185  * dereferencing @ptr must be assignable to @x without a cast.
 186  *
 187  * Returns zero on success, or -EFAULT on error.
 188  * On error, the variable @x is set to zero.
 189  */
 190 #define get_user(x,ptr) \
 191         __get_user_check((x), (ptr), sizeof(*(ptr)))
 192
 193 /*
 194  * __put_user: - Write a simple value into user space, with less checking.
 195  * @x:   Value to copy to user space.
 196  * @ptr: Destination address, in user space.
 197  *
 198  * Context: User context only. This function may sleep if pagefaults are
 199  *          enabled.
 200  *
 201  * This macro copies a single simple value from kernel space to user
 202  * space.  It supports simple types like char and int, but not larger
 203  * data types like structures or arrays.
 204  *
 205  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 206  * to the result of dereferencing @ptr.
 207  *
 208  * Caller must check the pointer with access_ok() before calling this
 209  * function.
 210  *
 211  * Returns zero on success, or -EFAULT on error.
 212  */
 213 #define __put_user(x,ptr) \
 214         __put_user_nocheck((x), (ptr), sizeof(*(ptr)))
 215
 216 /*
 217  * __get_user: - Get a simple variable from user space, with less checking.
 218  * @x:   Variable to store result.
 219  * @ptr: Source address, in user space.
 220  *
 221  * Context: User context only. This function may sleep if pagefaults are
 222  *          enabled.
 223  *
 224  * This macro copies a single simple variable from user space to kernel
 225  * space.  It supports simple types like char and int, but not larger
 226  * data types like structures or arrays.
 227  *
 228  * @ptr must have pointer-to-simple-variable type, and the result of
 229  * dereferencing @ptr must be assignable to @x without a cast.
 230  *
 231  * Caller must check the pointer with access_ok() before calling this
 232  * function.
 233  *
 234  * Returns zero on success, or -EFAULT on error.
 235  * On error, the variable @x is set to zero.
 236  */
 237 #define __get_user(x,ptr) \
 238         __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
 239
 240 struct __large_struct { unsigned long buf[100]; };
 241 #define __m(x) (*(struct __large_struct __user *)(x))
 242
 243 /*
 244  * Yuck.  We need two variants, one for 64bit operation and one
 245  * for 32 bit mode and old iron.
 246  */
 247 #ifndef CONFIG_EVA
 248 #define __get_kernel_common(val, size, ptr) __get_user_common(val, size, ptr)
 249 #else
 250 /*
 251  * Kernel specific functions for EVA. We need to use normal load instructions
 252  * to read data from kernel when operating in EVA mode. We use these macros to
 253  * avoid redefining __get_user_asm for EVA.
 254  */
 255 #undef _loadd
 256 #undef _loadw
 257 #undef _loadh
 258 #undef _loadb
 259 #ifdef CONFIG_32BIT
 260 #define _loadd                  _loadw
 261 #else
 262 #define _loadd(reg, addr)       "ld " reg ", " addr
 263 #endif
 264 #define _loadw(reg, addr)       "lw " reg ", " addr
 265 #define _loadh(reg, addr)       "lh " reg ", " addr
 266 #define _loadb(reg, addr)       "lb " reg ", " addr
 267
 268 #define __get_kernel_common(val, size, ptr)                             \
 269 do {                                                                    \
 270         switch (size) {                                                 \
 271         case 1: __get_data_asm(val, _loadb, ptr); break;                \
 272         case 2: __get_data_asm(val, _loadh, ptr); break;                \
 273         case 4: __get_data_asm(val, _loadw, ptr); break;                \
 274         case 8: __GET_DW(val, _loadd, ptr); break;                      \
 275         default: __get_user_unknown(); break;                           \
 276         }                                                               \
 277 } while (0)
 278 #endif
 279
 280 #ifdef CONFIG_32BIT
 281 #define __GET_DW(val, insn, ptr) __get_data_asm_ll32(val, insn, ptr)
 282 #endif
 283 #ifdef CONFIG_64BIT
 284 #define __GET_DW(val, insn, ptr) __get_data_asm(val, insn, ptr)
 285 #endif
 286
 287 extern void __get_user_unknown(void);
 288
 289 #define __get_user_common(val, size, ptr)                               \
 290 do {                                                                    \
 291         switch (size) {                                                 \
 292         case 1: __get_data_asm(val, user_lb, ptr); break;               \
 293         case 2: __get_data_asm(val, user_lh, ptr); break;               \
 294         case 4: __get_data_asm(val, user_lw, ptr); break;               \
 295         case 8: __GET_DW(val, user_ld, ptr); break;                     \
 296         default: __get_user_unknown(); break;                           \
 297         }                                                               \
 298 } while (0)
 299
 300 #define __get_user_nocheck(x, ptr, size)                                \
 301 ({                                                                      \
 302         int __gu_err;                                                   \
 303                                                                         \
 304         if (eva_kernel_access()) {                                      \
 305                 __get_kernel_common((x), size, ptr);                    \
 306         } else {                                                        \
 307                 __chk_user_ptr(ptr);                                    \
 308                 __get_user_common((x), size, ptr);                      \
 309         }                                                               \
 310         __gu_err;                                                       \
 311 })
 312
 313 #define __get_user_check(x, ptr, size)                                  \
 314 ({                                                                      \
 315         int __gu_err = -EFAULT;                                         \
 316         const __typeof__(*(ptr)) __user * __gu_ptr = (ptr);             \
 317                                                                         \
 318         might_fault();                                                  \
 319         if (likely(access_ok(VERIFY_READ,  __gu_ptr, size))) {          \
 320                 if (eva_kernel_access())                                \
 321                         __get_kernel_common((x), size, __gu_ptr);       \
 322                 else                                                    \
 323                         __get_user_common((x), size, __gu_ptr);         \
 324         } else                                                          \
 325                 (x) = 0;                                                \
 326                                                                         \
 327         __gu_err;                                                       \
 328 })
 329
 330 #define __get_data_asm(val, insn, addr)                                 \
 331 {                                                                       \
 332         long __gu_tmp;                                                  \
 333                                                                         \
 334         __asm__ __volatile__(                                           \
 335         "1:     "insn("%1", "%3")"                              \n"     \
 336         "2:                                                     \n"     \
 337         "       .insn                                           \n"     \
 338         "       .section .fixup,\"ax\"                          \n"     \
 339         "3:     li      %0, %4                                  \n"     \
 340         "       move    %1, $0                                  \n"     \
 341         "       j       2b                                      \n"     \
 342         "       .previous                                       \n"     \
 343         "       .section __ex_table,\"a\"                       \n"     \
 344         "       "__UA_ADDR "\t1b, 3b                            \n"     \
 345         "       .previous                                       \n"     \
 346         : "=r" (__gu_err), "=r" (__gu_tmp)                              \
 347         : "0" (0), "o" (__m(addr)), "i" (-EFAULT));                     \
 348                                                                         \
 349         (val) = (__typeof__(*(addr))) __gu_tmp;                         \
 350 }
 351
 352 /*
 353  * Get a long long 64 using 32 bit registers.
 354  */
 355 #define __get_data_asm_ll32(val, insn, addr)                            \
 356 {                                                                       \
 357         union {                                                         \
 358                 unsigned long long      l;                              \
 359                 __typeof__(*(addr))     t;                              \
 360         } __gu_tmp;                                                     \
 361                                                                         \
 362         __asm__ __volatile__(                                           \
 363         "1:     " insn("%1", "(%3)")"                           \n"     \
 364         "2:     " insn("%D1", "4(%3)")"                         \n"     \
 365         "3:                                                     \n"     \
 366         "       .insn                                           \n"     \
 367         "       .section        .fixup,\"ax\"                   \n"     \
 368         "4:     li      %0, %4                                  \n"     \
 369         "       move    %1, $0                                  \n"     \
 370         "       move    %D1, $0                                 \n"     \
 371         "       j       3b                                      \n"     \
 372         "       .previous                                       \n"     \
 373         "       .section        __ex_table,\"a\"                \n"     \
 374         "       " __UA_ADDR "   1b, 4b                          \n"     \
 375         "       " __UA_ADDR "   2b, 4b                          \n"     \
 376         "       .previous                                       \n"     \
 377         : "=r" (__gu_err), "=&r" (__gu_tmp.l)                           \
 378         : "0" (0), "r" (addr), "i" (-EFAULT));                          \
 379                                                                         \
 380         (val) = __gu_tmp.t;                                             \
 381 }
 382
 383 #ifndef CONFIG_EVA
 384 #define __put_kernel_common(ptr, size) __put_user_common(ptr, size)
 385 #else
 386 /*
 387  * Kernel specific functions for EVA. We need to use normal load instructions
 388  * to read data from kernel when operating in EVA mode. We use these macros to
 389  * avoid redefining __get_data_asm for EVA.
 390  */
 391 #undef _stored
 392 #undef _storew
 393 #undef _storeh
 394 #undef _storeb
 395 #ifdef CONFIG_32BIT
 396 #define _stored                 _storew
 397 #else
 398 #define _stored(reg, addr)      "ld " reg ", " addr
 399 #endif
 400
 401 #define _storew(reg, addr)      "sw " reg ", " addr
 402 #define _storeh(reg, addr)      "sh " reg ", " addr
 403 #define _storeb(reg, addr)      "sb " reg ", " addr
 404
 405 #define __put_kernel_common(ptr, size)                                  \
 406 do {                                                                    \
 407         switch (size) {                                                 \
 408         case 1: __put_data_asm(_storeb, ptr); break;                    \
 409         case 2: __put_data_asm(_storeh, ptr); break;                    \
 410         case 4: __put_data_asm(_storew, ptr); break;                    \
 411         case 8: __PUT_DW(_stored, ptr); break;                          \
 412         default: __put_user_unknown(); break;                           \
 413         }                                                               \
 414 } while(0)
 415 #endif
 416
 417 /*
 418  * Yuck.  We need two variants, one for 64bit operation and one
 419  * for 32 bit mode and old iron.
 420  */
 421 #ifdef CONFIG_32BIT
 422 #define __PUT_DW(insn, ptr) __put_data_asm_ll32(insn, ptr)
 423 #endif
 424 #ifdef CONFIG_64BIT
 425 #define __PUT_DW(insn, ptr) __put_data_asm(insn, ptr)
 426 #endif
 427
 428 #define __put_user_common(ptr, size)                                    \
 429 do {                                                                    \
 430         switch (size) {                                                 \
 431         case 1: __put_data_asm(user_sb, ptr); break;                    \
 432         case 2: __put_data_asm(user_sh, ptr); break;                    \
 433         case 4: __put_data_asm(user_sw, ptr); break;                    \
 434         case 8: __PUT_DW(user_sd, ptr); break;                          \
 435         default: __put_user_unknown(); break;                           \
 436         }                                                               \
 437 } while (0)
 438
 439 #define __put_user_nocheck(x, ptr, size)                                \
 440 ({                                                                      \
 441         __typeof__(*(ptr)) __pu_val;                                    \
 442         int __pu_err = 0;                                               \
 443                                                                         \
 444         __pu_val = (x);                                                 \
 445         if (eva_kernel_access()) {                                      \
 446                 __put_kernel_common(ptr, size);                         \
 447         } else {                                                        \
 448                 __chk_user_ptr(ptr);                                    \
 449                 __put_user_common(ptr, size);                           \
 450         }                                                               \
 451         __pu_err;                                                       \
 452 })
 453
 454 #define __put_user_check(x, ptr, size)                                  \
 455 ({                                                                      \
 456         __typeof__(*(ptr)) __user *__pu_addr = (ptr);                   \
 457         __typeof__(*(ptr)) __pu_val = (x);                              \
 458         int __pu_err = -EFAULT;                                         \
 459                                                                         \
 460         might_fault();                                                  \
 461         if (likely(access_ok(VERIFY_WRITE,  __pu_addr, size))) {        \
 462                 if (eva_kernel_access())                                \
 463                         __put_kernel_common(__pu_addr, size);           \
 464                 else                                                    \
 465                         __put_user_common(__pu_addr, size);             \
 466         }                                                               \
 467                                                                         \
 468         __pu_err;                                                       \
 469 })
 470
 471 #define __put_data_asm(insn, ptr)                                       \
 472 {                                                                       \
 473         __asm__ __volatile__(                                           \
 474         "1:     "insn("%z2", "%3")"     # __put_data_asm        \n"     \
 475         "2:                                                     \n"     \
 476         "       .insn                                           \n"     \
 477         "       .section        .fixup,\"ax\"                   \n"     \
 478         "3:     li      %0, %4                                  \n"     \
 479         "       j       2b                                      \n"     \
 480         "       .previous                                       \n"     \
 481         "       .section        __ex_table,\"a\"                \n"     \
 482         "       " __UA_ADDR "   1b, 3b                          \n"     \
 483         "       .previous                                       \n"     \
 484         : "=r" (__pu_err)                                               \
 485         : "0" (0), "Jr" (__pu_val), "o" (__m(ptr)),                     \
 486           "i" (-EFAULT));                                               \
 487 }
 488
 489 #define __put_data_asm_ll32(insn, ptr)                                  \
 490 {                                                                       \
 491         __asm__ __volatile__(                                           \
 492         "1:     "insn("%2", "(%3)")"    # __put_data_asm_ll32   \n"     \
 493         "2:     "insn("%D2", "4(%3)")"                          \n"     \
 494         "3:                                                     \n"     \
 495         "       .insn                                           \n"     \
 496         "       .section        .fixup,\"ax\"                   \n"     \
 497         "4:     li      %0, %4                                  \n"     \
 498         "       j       3b                                      \n"     \
 499         "       .previous                                       \n"     \
 500         "       .section        __ex_table,\"a\"                \n"     \
 501         "       " __UA_ADDR "   1b, 4b                          \n"     \
 502         "       " __UA_ADDR "   2b, 4b                          \n"     \
 503         "       .previous"                                              \
 504         : "=r" (__pu_err)                                               \
 505         : "0" (0), "r" (__pu_val), "r" (ptr),                           \
 506           "i" (-EFAULT));                                               \
 507 }
 508
 509 extern void __put_user_unknown(void);
 510
 511 /*
 512  * ul{b,h,w} are macros and there are no equivalent macros for EVA.
 513  * EVA unaligned access is handled in the ADE exception handler.
 514  */
 515 #ifndef CONFIG_EVA
 516 /*
 517  * put_user_unaligned: - Write a simple value into user space.
 518  * @x:   Value to copy to user space.
 519  * @ptr: Destination address, in user space.
 520  *
 521  * Context: User context only. This function may sleep if pagefaults are
 522  *          enabled.
 523  *
 524  * This macro copies a single simple value from kernel space to user
 525  * space.  It supports simple types like char and int, but not larger
 526  * data types like structures or arrays.
 527  *
 528  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 529  * to the result of dereferencing @ptr.
 530  *
 531  * Returns zero on success, or -EFAULT on error.
 532  */
 533 #define put_user_unaligned(x,ptr)       \
 534         __put_user_unaligned_check((x),(ptr),sizeof(*(ptr)))
 535
 536 /*
 537  * get_user_unaligned: - Get a simple variable from user space.
 538  * @x:   Variable to store result.
 539  * @ptr: Source address, in user space.
 540  *
 541  * Context: User context only. This function may sleep if pagefaults are
 542  *          enabled.
 543  *
 544  * This macro copies a single simple variable from user space to kernel
 545  * space.  It supports simple types like char and int, but not larger
 546  * data types like structures or arrays.
 547  *
 548  * @ptr must have pointer-to-simple-variable type, and the result of
 549  * dereferencing @ptr must be assignable to @x without a cast.
 550  *
 551  * Returns zero on success, or -EFAULT on error.
 552  * On error, the variable @x is set to zero.
 553  */
 554 #define get_user_unaligned(x,ptr) \
 555         __get_user_unaligned_check((x),(ptr),sizeof(*(ptr)))
 556
 557 /*
 558  * __put_user_unaligned: - Write a simple value into user space, with less checking.
 559  * @x:   Value to copy to user space.
 560  * @ptr: Destination address, in user space.
 561  *
 562  * Context: User context only. This function may sleep if pagefaults are
 563  *          enabled.
 564  *
 565  * This macro copies a single simple value from kernel space to user
 566  * space.  It supports simple types like char and int, but not larger
 567  * data types like structures or arrays.
 568  *
 569  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 570  * to the result of dereferencing @ptr.
 571  *
 572  * Caller must check the pointer with access_ok() before calling this
 573  * function.
 574  *
 575  * Returns zero on success, or -EFAULT on error.
 576  */
 577 #define __put_user_unaligned(x,ptr) \
 578         __put_user_unaligned_nocheck((x),(ptr),sizeof(*(ptr)))
 579
 580 /*
 581  * __get_user_unaligned: - Get a simple variable from user space, with less checking.
 582  * @x:   Variable to store result.
 583  * @ptr: Source address, in user space.
 584  *
 585  * Context: User context only. This function may sleep if pagefaults are
 586  *          enabled.
 587  *
 588  * This macro copies a single simple variable from user space to kernel
 589  * space.  It supports simple types like char and int, but not larger
 590  * data types like structures or arrays.
 591  *
 592  * @ptr must have pointer-to-simple-variable type, and the result of
 593  * dereferencing @ptr must be assignable to @x without a cast.
 594  *
 595  * Caller must check the pointer with access_ok() before calling this
 596  * function.
 597  *
 598  * Returns zero on success, or -EFAULT on error.
 599  * On error, the variable @x is set to zero.
 600  */
 601 #define __get_user_unaligned(x,ptr) \
 602         __get_user_unaligned_nocheck((x),(ptr),sizeof(*(ptr)))
 603
 604 /*
 605  * Yuck.  We need two variants, one for 64bit operation and one
 606  * for 32 bit mode and old iron.
 607  */
 608 #ifdef CONFIG_32BIT
 609 #define __GET_USER_UNALIGNED_DW(val, ptr)                               \
 610         __get_user_unaligned_asm_ll32(val, ptr)
 611 #endif
 612 #ifdef CONFIG_64BIT
 613 #define __GET_USER_UNALIGNED_DW(val, ptr)                               \
 614         __get_user_unaligned_asm(val, "uld", ptr)
 615 #endif
 616
 617 extern void __get_user_unaligned_unknown(void);
 618
 619 #define __get_user_unaligned_common(val, size, ptr)                     \
 620 do {                                                                    \
 621         switch (size) {                                                 \
 622         case 1: __get_data_asm(val, "lb", ptr); break;                  \
 623         case 2: __get_data_unaligned_asm(val, "ulh", ptr); break;       \
 624         case 4: __get_data_unaligned_asm(val, "ulw", ptr); break;       \
 625         case 8: __GET_USER_UNALIGNED_DW(val, ptr); break;               \
 626         default: __get_user_unaligned_unknown(); break;                 \
 627         }                                                               \
 628 } while (0)
 629
 630 #define __get_user_unaligned_nocheck(x,ptr,size)                        \
 631 ({                                                                      \
 632         int __gu_err;                                                   \
 633                                                                         \
 634         __get_user_unaligned_common((x), size, ptr);                    \
 635         __gu_err;                                                       \
 636 })
 637
 638 #define __get_user_unaligned_check(x,ptr,size)                          \
 639 ({                                                                      \
 640         int __gu_err = -EFAULT;                                         \
 641         const __typeof__(*(ptr)) __user * __gu_ptr = (ptr);             \
 642                                                                         \
 643         if (likely(access_ok(VERIFY_READ,  __gu_ptr, size)))            \
 644                 __get_user_unaligned_common((x), size, __gu_ptr);       \
 645                                                                         \
 646         __gu_err;                                                       \
 647 })
 648
 649 #define __get_data_unaligned_asm(val, insn, addr)                       \
 650 {                                                                       \
 651         long __gu_tmp;                                                  \
 652                                                                         \
 653         __asm__ __volatile__(                                           \
 654         "1:     " insn "        %1, %3                          \n"     \
 655         "2:                                                     \n"     \
 656         "       .insn                                           \n"     \
 657         "       .section .fixup,\"ax\"                          \n"     \
 658         "3:     li      %0, %4                                  \n"     \
 659         "       move    %1, $0                                  \n"     \
 660         "       j       2b                                      \n"     \
 661         "       .previous                                       \n"     \
 662         "       .section __ex_table,\"a\"                       \n"     \
 663         "       "__UA_ADDR "\t1b, 3b                            \n"     \
 664         "       "__UA_ADDR "\t1b + 4, 3b                        \n"     \
 665         "       .previous                                       \n"     \
 666         : "=r" (__gu_err), "=r" (__gu_tmp)                              \
 667         : "0" (0), "o" (__m(addr)), "i" (-EFAULT));                     \
 668                                                                         \
 669         (val) = (__typeof__(*(addr))) __gu_tmp;                         \
 670 }
 671
 672 /*
 673  * Get a long long 64 using 32 bit registers.
 674  */
 675 #define __get_user_unaligned_asm_ll32(val, addr)                        \
 676 {                                                                       \
 677         unsigned long long __gu_tmp;                                    \
 678                                                                         \
 679         __asm__ __volatile__(                                           \
 680         "1:     ulw     %1, (%3)                                \n"     \
 681         "2:     ulw     %D1, 4(%3)                              \n"     \
 682         "       move    %0, $0                                  \n"     \
 683         "3:                                                     \n"     \
 684         "       .insn                                           \n"     \
 685         "       .section        .fixup,\"ax\"                   \n"     \
 686         "4:     li      %0, %4                                  \n"     \
 687         "       move    %1, $0                                  \n"     \
 688         "       move    %D1, $0                                 \n"     \
 689         "       j       3b                                      \n"     \
 690         "       .previous                                       \n"     \
 691         "       .section        __ex_table,\"a\"                \n"     \
 692         "       " __UA_ADDR "   1b, 4b                          \n"     \
 693         "       " __UA_ADDR "   1b + 4, 4b                      \n"     \
 694         "       " __UA_ADDR "   2b, 4b                          \n"     \
 695         "       " __UA_ADDR "   2b + 4, 4b                      \n"     \
 696         "       .previous                                       \n"     \
 697         : "=r" (__gu_err), "=&r" (__gu_tmp)                             \
 698         : "0" (0), "r" (addr), "i" (-EFAULT));                          \
 699         (val) = (__typeof__(*(addr))) __gu_tmp;                         \
 700 }
 701
 702 /*
 703  * Yuck.  We need two variants, one for 64bit operation and one
 704  * for 32 bit mode and old iron.
 705  */
 706 #ifdef CONFIG_32BIT
 707 #define __PUT_USER_UNALIGNED_DW(ptr) __put_user_unaligned_asm_ll32(ptr)
 708 #endif
 709 #ifdef CONFIG_64BIT
 710 #define __PUT_USER_UNALIGNED_DW(ptr) __put_user_unaligned_asm("usd", ptr)
 711 #endif
 712
 713 #define __put_user_unaligned_common(ptr, size)                          \
 714 do {                                                                    \
 715         switch (size) {                                                 \
 716         case 1: __put_data_asm("sb", ptr); break;                       \
 717         case 2: __put_user_unaligned_asm("ush", ptr); break;            \
 718         case 4: __put_user_unaligned_asm("usw", ptr); break;            \
 719         case 8: __PUT_USER_UNALIGNED_DW(ptr); break;                    \
 720         default: __put_user_unaligned_unknown(); break;                 \
 721 } while (0)
 722
 723 #define __put_user_unaligned_nocheck(x,ptr,size)                        \
 724 ({                                                                      \
 725         __typeof__(*(ptr)) __pu_val;                                    \
 726         int __pu_err = 0;                                               \
 727                                                                         \
 728         __pu_val = (x);                                                 \
 729         __put_user_unaligned_common(ptr, size);                         \
 730         __pu_err;                                                       \
 731 })
 732
 733 #define __put_user_unaligned_check(x,ptr,size)                          \
 734 ({                                                                      \
 735         __typeof__(*(ptr)) __user *__pu_addr = (ptr);                   \
 736         __typeof__(*(ptr)) __pu_val = (x);                              \
 737         int __pu_err = -EFAULT;                                         \
 738                                                                         \
 739         if (likely(access_ok(VERIFY_WRITE,  __pu_addr, size)))          \
 740                 __put_user_unaligned_common(__pu_addr, size);           \
 741                                                                         \
 742         __pu_err;                                                       \
 743 })
 744
 745 #define __put_user_unaligned_asm(insn, ptr)                             \
 746 {                                                                       \
 747         __asm__ __volatile__(                                           \
 748         "1:     " insn "        %z2, %3         # __put_user_unaligned_asm\n" \
 749         "2:                                                     \n"     \
 750         "       .insn                                           \n"     \
 751         "       .section        .fixup,\"ax\"                   \n"     \
 752         "3:     li      %0, %4                                  \n"     \
 753         "       j       2b                                      \n"     \
 754         "       .previous                                       \n"     \
 755         "       .section        __ex_table,\"a\"                \n"     \
 756         "       " __UA_ADDR "   1b, 3b                          \n"     \
 757         "       .previous                                       \n"     \
 758         : "=r" (__pu_err)                                               \
 759         : "0" (0), "Jr" (__pu_val), "o" (__m(ptr)),                     \
 760           "i" (-EFAULT));                                               \
 761 }
 762
 763 #define __put_user_unaligned_asm_ll32(ptr)                              \
 764 {                                                                       \
 765         __asm__ __volatile__(                                           \
 766         "1:     sw      %2, (%3)        # __put_user_unaligned_asm_ll32 \n" \
 767         "2:     sw      %D2, 4(%3)                              \n"     \
 768         "3:                                                     \n"     \
 769         "       .insn                                           \n"     \
 770         "       .section        .fixup,\"ax\"                   \n"     \
 771         "4:     li      %0, %4                                  \n"     \
 772         "       j       3b                                      \n"     \
 773         "       .previous                                       \n"     \
 774         "       .section        __ex_table,\"a\"                \n"     \
 775         "       " __UA_ADDR "   1b, 4b                          \n"     \
 776         "       " __UA_ADDR "   1b + 4, 4b                      \n"     \
 777         "       " __UA_ADDR "   2b, 4b                          \n"     \
 778         "       " __UA_ADDR "   2b + 4, 4b                      \n"     \
 779         "       .previous"                                              \
 780         : "=r" (__pu_err)                                               \
 781         : "0" (0), "r" (__pu_val), "r" (ptr),                           \
 782           "i" (-EFAULT));                                               \
 783 }
 784
 785 extern void __put_user_unaligned_unknown(void);
 786 #endif
 787
 788 /*
 789  * We're generating jump to subroutines which will be outside the range of
 790  * jump instructions
 791  */
 792 #ifdef MODULE
 793 #define __MODULE_JAL(destination)                                       \
 794         ".set\tnoat\n\t"                                                \
 795         __UA_LA "\t$1, " #destination "\n\t"                            \
 796         "jalr\t$1\n\t"                                                  \
 797         ".set\tat\n\t"
 798 #else
 799 #define __MODULE_JAL(destination)                                       \
 800         "jal\t" #destination "\n\t"
 801 #endif
 802
 803 #if defined(CONFIG_CPU_DADDI_WORKAROUNDS) || (defined(CONFIG_EVA) &&    \
 804                                               defined(CONFIG_CPU_HAS_PREFETCH))
 805 #define DADDI_SCRATCH "$3"
 806 #else
 807 #define DADDI_SCRATCH "$0"
 808 #endif
 809
 810 extern size_t __copy_user(void *__to, const void *__from, size_t __n);
 811
 812 #ifndef CONFIG_EVA
 813 #define __invoke_copy_to_user(to, from, n)                              \
 814 ({                                                                      \
 815         register void __user *__cu_to_r __asm__("$4");                  \
 816         register const void *__cu_from_r __asm__("$5");                 \
 817         register long __cu_len_r __asm__("$6");                         \
 818                                                                         \
 819         __cu_to_r = (to);                                               \
 820         __cu_from_r = (from);                                           \
 821         __cu_len_r = (n);                                               \
 822         __asm__ __volatile__(                                           \
 823         __MODULE_JAL(__copy_user)                                       \
 824         : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)       \
 825         :                                                               \
 826         : "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",  \
 827           DADDI_SCRATCH, "memory");                                     \
 828         __cu_len_r;                                                     \
 829 })
 830
 831 #define __invoke_copy_to_kernel(to, from, n)                            \
 832         __invoke_copy_to_user(to, from, n)
 833
 834 #endif
 835
 836 /*
 837  * __copy_to_user: - Copy a block of data into user space, with less checking.
 838  * @to:   Destination address, in user space.
 839  * @from: Source address, in kernel space.
 840  * @n:    Number of bytes to copy.
 841  *
 842  * Context: User context only. This function may sleep if pagefaults are
 843  *          enabled.
 844  *
 845  * Copy data from kernel space to user space.  Caller must check
 846  * the specified block with access_ok() before calling this function.
 847  *
 848  * Returns number of bytes that could not be copied.
 849  * On success, this will be zero.
 850  */
 851 #define __copy_to_user(to, from, n)                                     \
 852 ({                                                                      \
 853         void __user *__cu_to;                                           \
 854         const void *__cu_from;                                          \
 855         long __cu_len;                                                  \
 856                                                                         \
 857         __cu_to = (to);                                                 \
 858         __cu_from = (from);                                             \
 859         __cu_len = (n);                                                 \
 860         might_fault();                                                  \
 861         if (eva_kernel_access())                                        \
 862                 __cu_len = __invoke_copy_to_kernel(__cu_to, __cu_from,  \
 863                                                    __cu_len);           \
 864         else                                                            \
 865                 __cu_len = __invoke_copy_to_user(__cu_to, __cu_from,    \
 866                                                  __cu_len);             \
 867         __cu_len;                                                       \
 868 })
 869
 870 extern size_t __copy_user_inatomic(void *__to, const void *__from, size_t __n);
 871
 872 #define __copy_to_user_inatomic(to, from, n)                            \
 873 ({                                                                      \
 874         void __user *__cu_to;                                           \
 875         const void *__cu_from;                                          \
 876         long __cu_len;                                                  \
 877                                                                         \
 878         __cu_to = (to);                                                 \
 879         __cu_from = (from);                                             \
 880         __cu_len = (n);                                                 \
 881         if (eva_kernel_access())                                        \
 882                 __cu_len = __invoke_copy_to_kernel(__cu_to, __cu_from,  \
 883                                                    __cu_len);           \
 884         else                                                            \
 885                 __cu_len = __invoke_copy_to_user(__cu_to, __cu_from,    \
 886                                                  __cu_len);             \
 887         __cu_len;                                                       \
 888 })
 889
 890 #define __copy_from_user_inatomic(to, from, n)                          \
 891 ({                                                                      \
 892         void *__cu_to;                                                  \
 893         const void __user *__cu_from;                                   \
 894         long __cu_len;                                                  \
 895                                                                         \
 896         __cu_to = (to);                                                 \
 897         __cu_from = (from);                                             \
 898         __cu_len = (n);                                                 \
 899         if (eva_kernel_access())                                        \
 900                 __cu_len = __invoke_copy_from_kernel_inatomic(__cu_to,  \
 901                                                               __cu_from,\
 902                                                               __cu_len);\
 903         else                                                            \
 904                 __cu_len = __invoke_copy_from_user_inatomic(__cu_to,    \
 905                                                             __cu_from,  \
 906                                                             __cu_len);  \
 907         __cu_len;                                                       \
 908 })
 909
 910 /*
 911  * copy_to_user: - Copy a block of data into user space.
 912  * @to:   Destination address, in user space.
 913  * @from: Source address, in kernel space.
 914  * @n:    Number of bytes to copy.
 915  *
 916  * Context: User context only. This function may sleep if pagefaults are
 917  *          enabled.
 918  *
 919  * Copy data from kernel space to user space.
 920  *
 921  * Returns number of bytes that could not be copied.
 922  * On success, this will be zero.
 923  */
 924 #define copy_to_user(to, from, n)                                       \
 925 ({                                                                      \
 926         void __user *__cu_to;                                           \
 927         const void *__cu_from;                                          \
 928         long __cu_len;                                                  \
 929                                                                         \
 930         __cu_to = (to);                                                 \
 931         __cu_from = (from);                                             \
 932         __cu_len = (n);                                                 \
 933         if (eva_kernel_access()) {                                      \
 934                 __cu_len = __invoke_copy_to_kernel(__cu_to,             \
 935                                                    __cu_from,           \
 936                                                    __cu_len);           \
 937         } else {                                                        \
 938                 if (access_ok(VERIFY_WRITE, __cu_to, __cu_len)) {       \
 939                         might_fault();                                  \
 940                         __cu_len = __invoke_copy_to_user(__cu_to,       \
 941                                                          __cu_from,     \
 942                                                          __cu_len);     \
 943                 }                                                       \
 944         }                                                               \
 945         __cu_len;                                                       \
 946 })
 947
 948 #ifndef CONFIG_EVA
 949
 950 #define __invoke_copy_from_user(to, from, n)                            \
 951 ({                                                                      \
 952         register void *__cu_to_r __asm__("$4");                         \
 953         register const void __user *__cu_from_r __asm__("$5");          \
 954         register long __cu_len_r __asm__("$6");                         \
 955                                                                         \
 956         __cu_to_r = (to);                                               \
 957         __cu_from_r = (from);                                           \
 958         __cu_len_r = (n);                                               \
 959         __asm__ __volatile__(                                           \
 960         ".set\tnoreorder\n\t"                                           \
 961         __MODULE_JAL(__copy_user)                                       \
 962         ".set\tnoat\n\t"                                                \
 963         __UA_ADDU "\t$1, %1, %2\n\t"                                    \
 964         ".set\tat\n\t"                                                  \
 965         ".set\treorder"                                                 \
 966         : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)       \
 967         :                                                               \
 968         : "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",  \
 969           DADDI_SCRATCH, "memory");                                     \
 970         __cu_len_r;                                                     \
 971 })
 972
 973 #define __invoke_copy_from_kernel(to, from, n)                          \
 974         __invoke_copy_from_user(to, from, n)
 975
 976 /* For userland <-> userland operations */
 977 #define ___invoke_copy_in_user(to, from, n)                             \
 978         __invoke_copy_from_user(to, from, n)
 979
 980 /* For kernel <-> kernel operations */
 981 #define ___invoke_copy_in_kernel(to, from, n)                           \
 982         __invoke_copy_from_user(to, from, n)
 983
 984 #define __invoke_copy_from_user_inatomic(to, from, n)                   \
 985 ({                                                                      \
 986         register void *__cu_to_r __asm__("$4");                         \
 987         register const void __user *__cu_from_r __asm__("$5");          \
 988         register long __cu_len_r __asm__("$6");                         \
 989                                                                         \
 990         __cu_to_r = (to);                                               \
 991         __cu_from_r = (from);                                           \
 992         __cu_len_r = (n);                                               \
 993         __asm__ __volatile__(                                           \
 994         ".set\tnoreorder\n\t"                                           \
 995         __MODULE_JAL(__copy_user_inatomic)                              \
 996         ".set\tnoat\n\t"                                                \
 997         __UA_ADDU "\t$1, %1, %2\n\t"                                    \
 998         ".set\tat\n\t"                                                  \
 999         ".set\treorder"                                                 \
1000         : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)       \
1001         :                                                               \
1002         : "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",  \
1003           DADDI_SCRATCH, "memory");                                     \
1004         __cu_len_r;                                                     \
1005 })
1006
1007 #define __invoke_copy_from_kernel_inatomic(to, from, n)                 \
1008         __invoke_copy_from_user_inatomic(to, from, n)                   \
1009
1010 #else
1011
1012 /* EVA specific functions */
1013
1014 extern size_t __copy_user_inatomic_eva(void *__to, const void *__from,
1015                                        size_t __n);
1016 extern size_t __copy_from_user_eva(void *__to, const void *__from,
1017                                    size_t __n);
1018 extern size_t __copy_to_user_eva(void *__to, const void *__from,
1019                                  size_t __n);
1020 extern size_t __copy_in_user_eva(void *__to, const void *__from, size_t __n);
1021
1022 #define __invoke_copy_from_user_eva_generic(to, from, n, func_ptr)      \
1023 ({                                                                      \
1024         register void *__cu_to_r __asm__("$4");                         \
1025         register const void __user *__cu_from_r __asm__("$5");          \
1026         register long __cu_len_r __asm__("$6");                         \
1027                                                                         \
1028         __cu_to_r = (to);                                               \
1029         __cu_from_r = (from);                                           \
1030         __cu_len_r = (n);                                               \
1031         __asm__ __volatile__(                                           \
1032         ".set\tnoreorder\n\t"                                           \
1033         __MODULE_JAL(func_ptr)                                          \
1034         ".set\tnoat\n\t"                                                \
1035         __UA_ADDU "\t$1, %1, %2\n\t"                                    \
1036         ".set\tat\n\t"                                                  \
1037         ".set\treorder"                                                 \
1038         : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)       \
1039         :                                                               \
1040         : "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",  \
1041           DADDI_SCRATCH, "memory");                                     \
1042         __cu_len_r;                                                     \
1043 })
1044
1045 #define __invoke_copy_to_user_eva_generic(to, from, n, func_ptr)        \
1046 ({                                                                      \
1047         register void *__cu_to_r __asm__("$4");                         \
1048         register const void __user *__cu_from_r __asm__("$5");          \
1049         register long __cu_len_r __asm__("$6");                         \
1050                                                                         \
1051         __cu_to_r = (to);                                               \
1052         __cu_from_r = (from);                                           \
1053         __cu_len_r = (n);                                               \
1054         __asm__ __volatile__(                                           \
1055         __MODULE_JAL(func_ptr)                                          \
1056         : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)       \
1057         :                                                               \
1058         : "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",  \
1059           DADDI_SCRATCH, "memory");                                     \
1060         __cu_len_r;                                                     \
1061 })
1062
1063 /*
1064  * Source or destination address is in userland. We need to go through
1065  * the TLB
1066  */
1067 #define __invoke_copy_from_user(to, from, n)                            \
1068         __invoke_copy_from_user_eva_generic(to, from, n, __copy_from_user_eva)
1069
1070 #define __invoke_copy_from_user_inatomic(to, from, n)                   \
1071         __invoke_copy_from_user_eva_generic(to, from, n,                \
1072                                             __copy_user_inatomic_eva)
1073
1074 #define __invoke_copy_to_user(to, from, n)                              \
1075         __invoke_copy_to_user_eva_generic(to, from, n, __copy_to_user_eva)
1076
1077 #define ___invoke_copy_in_user(to, from, n)                             \
1078         __invoke_copy_from_user_eva_generic(to, from, n, __copy_in_user_eva)
1079
1080 /*
1081  * Source or destination address in the kernel. We are not going through
1082  * the TLB
1083  */
1084 #define __invoke_copy_from_kernel(to, from, n)                          \
1085         __invoke_copy_from_user_eva_generic(to, from, n, __copy_user)
1086
1087 #define __invoke_copy_from_kernel_inatomic(to, from, n)                 \
1088         __invoke_copy_from_user_eva_generic(to, from, n, __copy_user_inatomic)
1089
1090 #define __invoke_copy_to_kernel(to, from, n)                            \
1091         __invoke_copy_to_user_eva_generic(to, from, n, __copy_user)
1092
1093 #define ___invoke_copy_in_kernel(to, from, n)                           \
1094         __invoke_copy_from_user_eva_generic(to, from, n, __copy_user)
1095
1096 #endif /* CONFIG_EVA */
1097
1098 /*
1099  * __copy_from_user: - Copy a block of data from user space, with less checking.
1100  * @to:   Destination address, in kernel space.
1101  * @from: Source address, in user space.
1102  * @n:    Number of bytes to copy.
1103  *
1104  * Context: User context only. This function may sleep if pagefaults are
1105  *          enabled.
1106  *
1107  * Copy data from user space to kernel space.  Caller must check
1108  * the specified block with access_ok() before calling this function.
1109  *
1110  * Returns number of bytes that could not be copied.
1111  * On success, this will be zero.
1112  *
1113  * If some data could not be copied, this function will pad the copied
1114  * data to the requested size using zero bytes.
1115  */
1116 #define __copy_from_user(to, from, n)                                   \
1117 ({                                                                      \
1118         void *__cu_to;                                                  \
1119         const void __user *__cu_from;                                   \
1120         long __cu_len;                                                  \
1121                                                                         \
1122         __cu_to = (to);                                                 \
1123         __cu_from = (from);                                             \
1124         __cu_len = (n);                                                 \
1125         if (eva_kernel_access()) {                                      \
1126                 __cu_len = __invoke_copy_from_kernel(__cu_to,           \
1127                                                      __cu_from,         \
1128                                                      __cu_len);         \
1129         } else {                                                        \
1130                 might_fault();                                          \
1131                 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from,  \
1132                                                    __cu_len);           \
1133         }                                                               \
1134         __cu_len;                                                       \
1135 })
1136
1137 /*
1138  * copy_from_user: - Copy a block of data from user space.
1139  * @to:   Destination address, in kernel space.
1140  * @from: Source address, in user space.
1141  * @n:    Number of bytes to copy.
1142  *
1143  * Context: User context only. This function may sleep if pagefaults are
1144  *          enabled.
1145  *
1146  * Copy data from user space to kernel space.
1147  *
1148  * Returns number of bytes that could not be copied.
1149  * On success, this will be zero.
1150  *
1151  * If some data could not be copied, this function will pad the copied
1152  * data to the requested size using zero bytes.
1153  */
1154 #define copy_from_user(to, from, n)                                     \
1155 ({                                                                      \
1156         void *__cu_to;                                                  \
1157         const void __user *__cu_from;                                   \
1158         long __cu_len;                                                  \
1159                                                                         \
1160         __cu_to = (to);                                                 \
1161         __cu_from = (from);                                             \
1162         __cu_len = (n);                                                 \
1163         if (eva_kernel_access()) {                                      \
1164                 __cu_len = __invoke_copy_from_kernel(__cu_to,           \
1165                                                      __cu_from,         \
1166                                                      __cu_len);         \
1167         } else {                                                        \
1168                 if (access_ok(VERIFY_READ, __cu_from, __cu_len)) {      \
1169                         might_fault();                                  \
1170                         __cu_len = __invoke_copy_from_user(__cu_to,     \
1171                                                            __cu_from,   \
1172                                                            __cu_len);   \
1173                 }                                                       \
1174         }                                                               \
1175         __cu_len;                                                       \
1176 })
1177
1178 #define __copy_in_user(to, from, n)                                     \
1179 ({                                                                      \
1180         void __user *__cu_to;                                           \
1181         const void __user *__cu_from;                                   \
1182         long __cu_len;                                                  \
1183                                                                         \
1184         __cu_to = (to);                                                 \
1185         __cu_from = (from);                                             \
1186         __cu_len = (n);                                                 \
1187         if (eva_kernel_access()) {                                      \
1188                 __cu_len = ___invoke_copy_in_kernel(__cu_to, __cu_from, \
1189                                                     __cu_len);          \
1190         } else {                                                        \
1191                 might_fault();                                          \
1192                 __cu_len = ___invoke_copy_in_user(__cu_to, __cu_from,   \
1193                                                   __cu_len);            \
1194         }                                                               \
1195         __cu_len;                                                       \
1196 })
1197
1198 #define copy_in_user(to, from, n)                                       \
1199 ({                                                                      \
1200         void __user *__cu_to;                                           \
1201         const void __user *__cu_from;                                   \
1202         long __cu_len;                                                  \
1203                                                                         \
1204         __cu_to = (to);                                                 \
1205         __cu_from = (from);                                             \
1206         __cu_len = (n);                                                 \
1207         if (eva_kernel_access()) {                                      \
1208                 __cu_len = ___invoke_copy_in_kernel(__cu_to,__cu_from,  \
1209                                                     __cu_len);          \
1210         } else {                                                        \
1211                 if (likely(access_ok(VERIFY_READ, __cu_from, __cu_len) &&\
1212                            access_ok(VERIFY_WRITE, __cu_to, __cu_len))) {\
1213                         might_fault();                                  \
1214                         __cu_len = ___invoke_copy_in_user(__cu_to,      \
1215                                                           __cu_from,    \
1216                                                           __cu_len);    \
1217                 }                                                       \
1218         }                                                               \
1219         __cu_len;                                                       \
1220 })
1221
1222 /*
1223  * __clear_user: - Zero a block of memory in user space, with less checking.
1224  * @to:   Destination address, in user space.
1225  * @n:    Number of bytes to zero.
1226  *
1227  * Zero a block of memory in user space.  Caller must check
1228  * the specified block with access_ok() before calling this function.
1229  *
1230  * Returns number of bytes that could not be cleared.
1231  * On success, this will be zero.
1232  */
1233 static inline __kernel_size_t
1234 __clear_user(void __user *addr, __kernel_size_t size)
1235 {
1236         __kernel_size_t res;
1237
1238         if (eva_kernel_access()) {
1239                 __asm__ __volatile__(
1240                         "move\t$4, %1\n\t"
1241                         "move\t$5, $0\n\t"
1242                         "move\t$6, %2\n\t"
1243                         __MODULE_JAL(__bzero_kernel)
1244                         "move\t%0, $6"
1245                         : "=r" (res)
1246                         : "r" (addr), "r" (size)
1247                         : "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
1248         } else {
1249                 might_fault();
1250                 __asm__ __volatile__(
1251                         "move\t$4, %1\n\t"
1252                         "move\t$5, $0\n\t"
1253                         "move\t$6, %2\n\t"
1254                         __MODULE_JAL(__bzero)
1255                         "move\t%0, $6"
1256                         : "=r" (res)
1257                         : "r" (addr), "r" (size)
1258                         : "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
1259         }
1260
1261         return res;
1262 }
1263
1264 #define clear_user(addr,n)                                              \
1265 ({                                                                      \
1266         void __user * __cl_addr = (addr);                               \
1267         unsigned long __cl_size = (n);                                  \
1268         if (__cl_size && access_ok(VERIFY_WRITE,                        \
1269                                         __cl_addr, __cl_size))          \
1270                 __cl_size = __clear_user(__cl_addr, __cl_size);         \
1271         __cl_size;                                                      \
1272 })
1273
1274 /*
1275  * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
1276  * @dst:   Destination address, in kernel space.  This buffer must be at
1277  *         least @count bytes long.
1278  * @src:   Source address, in user space.
1279  * @count: Maximum number of bytes to copy, including the trailing NUL.
1280  *
1281  * Copies a NUL-terminated string from userspace to kernel space.
1282  * Caller must check the specified block with access_ok() before calling
1283  * this function.
1284  *
1285  * On success, returns the length of the string (not including the trailing
1286  * NUL).
1287  *
1288  * If access to userspace fails, returns -EFAULT (some data may have been
1289  * copied).
1290  *
1291  * If @count is smaller than the length of the string, copies @count bytes
1292  * and returns @count.
1293  */
1294 static inline long
1295 __strncpy_from_user(char *__to, const char __user *__from, long __len)
1296 {
1297         long res;
1298
1299         if (eva_kernel_access()) {
1300                 __asm__ __volatile__(
1301                         "move\t$4, %1\n\t"
1302                         "move\t$5, %2\n\t"
1303                         "move\t$6, %3\n\t"
1304                         __MODULE_JAL(__strncpy_from_kernel_nocheck_asm)
1305                         "move\t%0, $2"
1306                         : "=r" (res)
1307                         : "r" (__to), "r" (__from), "r" (__len)
1308                         : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
1309         } else {
1310                 might_fault();
1311                 __asm__ __volatile__(
1312                         "move\t$4, %1\n\t"
1313                         "move\t$5, %2\n\t"
1314                         "move\t$6, %3\n\t"
1315                         __MODULE_JAL(__strncpy_from_user_nocheck_asm)
1316                         "move\t%0, $2"
1317                         : "=r" (res)
1318                         : "r" (__to), "r" (__from), "r" (__len)
1319                         : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
1320         }
1321
1322         return res;
1323 }
1324
1325 /*
1326  * strncpy_from_user: - Copy a NUL terminated string from userspace.
1327  * @dst:   Destination address, in kernel space.  This buffer must be at
1328  *         least @count bytes long.
1329  * @src:   Source address, in user space.
1330  * @count: Maximum number of bytes to copy, including the trailing NUL.
1331  *
1332  * Copies a NUL-terminated string from userspace to kernel space.
1333  *
1334  * On success, returns the length of the string (not including the trailing
1335  * NUL).
1336  *
1337  * If access to userspace fails, returns -EFAULT (some data may have been
1338  * copied).
1339  *
1340  * If @count is smaller than the length of the string, copies @count bytes
1341  * and returns @count.
1342  */
1343 static inline long
1344 strncpy_from_user(char *__to, const char __user *__from, long __len)
1345 {
1346         long res;
1347
1348         if (eva_kernel_access()) {
1349                 __asm__ __volatile__(
1350                         "move\t$4, %1\n\t"
1351                         "move\t$5, %2\n\t"
1352                         "move\t$6, %3\n\t"
1353                         __MODULE_JAL(__strncpy_from_kernel_asm)
1354                         "move\t%0, $2"
1355                         : "=r" (res)
1356                         : "r" (__to), "r" (__from), "r" (__len)
1357                         : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
1358         } else {
1359                 might_fault();
1360                 __asm__ __volatile__(
1361                         "move\t$4, %1\n\t"
1362                         "move\t$5, %2\n\t"
1363                         "move\t$6, %3\n\t"
1364                         __MODULE_JAL(__strncpy_from_user_asm)
1365                         "move\t%0, $2"
1366                         : "=r" (res)
1367                         : "r" (__to), "r" (__from), "r" (__len)
1368                         : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
1369         }
1370
1371         return res;
1372 }
1373
1374 /*
1375  * strlen_user: - Get the size of a string in user space.
1376  * @str: The string to measure.
1377  *
1378  * Context: User context only. This function may sleep if pagefaults are
1379  *          enabled.
1380  *
1381  * Get the size of a NUL-terminated string in user space.
1382  *
1383  * Returns the size of the string INCLUDING the terminating NUL.
1384  * On exception, returns 0.
1385  *
1386  * If there is a limit on the length of a valid string, you may wish to
1387  * consider using strnlen_user() instead.
1388  */
1389 static inline long strlen_user(const char __user *s)
1390 {
1391         long res;
1392
1393         if (eva_kernel_access()) {
1394                 __asm__ __volatile__(
1395                         "move\t$4, %1\n\t"
1396                         __MODULE_JAL(__strlen_kernel_asm)
1397                         "move\t%0, $2"
1398                         : "=r" (res)
1399                         : "r" (s)
1400                         : "$2", "$4", __UA_t0, "$31");
1401         } else {
1402                 might_fault();
1403                 __asm__ __volatile__(
1404                         "move\t$4, %1\n\t"
1405                         __MODULE_JAL(__strlen_user_asm)
1406                         "move\t%0, $2"
1407                         : "=r" (res)
1408                         : "r" (s)
1409                         : "$2", "$4", __UA_t0, "$31");
1410         }
1411
1412         return res;
1413 }
1414
1415 /* Returns: 0 if bad, string length+1 (memory size) of string if ok */
1416 static inline long __strnlen_user(const char __user *s, long n)
1417 {
1418         long res;
1419
1420         if (eva_kernel_access()) {
1421                 __asm__ __volatile__(
1422                         "move\t$4, %1\n\t"
1423                         "move\t$5, %2\n\t"
1424                         __MODULE_JAL(__strnlen_kernel_nocheck_asm)
1425                         "move\t%0, $2"
1426                         : "=r" (res)
1427                         : "r" (s), "r" (n)
1428                         : "$2", "$4", "$5", __UA_t0, "$31");
1429         } else {
1430                 might_fault();
1431                 __asm__ __volatile__(
1432                         "move\t$4, %1\n\t"
1433                         "move\t$5, %2\n\t"
1434                         __MODULE_JAL(__strnlen_user_nocheck_asm)
1435                         "move\t%0, $2"
1436                         : "=r" (res)
1437                         : "r" (s), "r" (n)
1438                         : "$2", "$4", "$5", __UA_t0, "$31");
1439         }
1440
1441         return res;
1442 }
1443
1444 /*
1445  * strnlen_user: - Get the size of a string in user space.
1446  * @str: The string to measure.
1447  *
1448  * Context: User context only. This function may sleep if pagefaults are
1449  *          enabled.
1450  *
1451  * Get the size of a NUL-terminated string in user space.
1452  *
1453  * Returns the size of the string INCLUDING the terminating NUL.
1454  * On exception, returns 0.
1455  * If the string is too long, returns a value greater than @n.
1456  */
1457 static inline long strnlen_user(const char __user *s, long n)
1458 {
1459         long res;
1460
1461         might_fault();
1462         if (eva_kernel_access()) {
1463                 __asm__ __volatile__(
1464                         "move\t$4, %1\n\t"
1465                         "move\t$5, %2\n\t"
1466                         __MODULE_JAL(__strnlen_kernel_asm)
1467                         "move\t%0, $2"
1468                         : "=r" (res)
1469                         : "r" (s), "r" (n)
1470                         : "$2", "$4", "$5", __UA_t0, "$31");
1471         } else {
1472                 __asm__ __volatile__(
1473                         "move\t$4, %1\n\t"
1474                         "move\t$5, %2\n\t"
1475                         __MODULE_JAL(__strnlen_user_asm)
1476                         "move\t%0, $2"
1477                         : "=r" (res)
1478                         : "r" (s), "r" (n)
1479                         : "$2", "$4", "$5", __UA_t0, "$31");
1480         }
1481
1482         return res;
1483 }
1484
1485 struct exception_table_entry
1486 {
1487         unsigned long insn;
1488         unsigned long nextinsn;
1489 };
1490
1491 extern int fixup_exception(struct pt_regs *regs);
1492
1493 #endif /* _ASM_UACCESS_H */