arch/x86/include/asm/percpu.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_X86_PERCPU_H
   3 #define _ASM_X86_PERCPU_H
   4
   5 #ifdef CONFIG_X86_64
   6 #define __percpu_seg            gs
   7 #define __percpu_mov_op         movq
   8 #else
   9 #define __percpu_seg            fs
  10 #define __percpu_mov_op         movl
  11 #endif
  12
  13 #ifdef __ASSEMBLY__
  14
  15 /*
  16  * PER_CPU finds an address of a per-cpu variable.
  17  *
  18  * Args:
  19  *    var - variable name
  20  *    reg - 32bit register
  21  *
  22  * The resulting address is stored in the "reg" argument.
  23  *
  24  * Example:
  25  *    PER_CPU(cpu_gdt_descr, %ebx)
  26  */
  27 #ifdef CONFIG_SMP
  28 #define PER_CPU(var, reg)                                               \
  29         __percpu_mov_op %__percpu_seg:this_cpu_off, reg;                \
  30         lea var(reg), reg
  31 #define PER_CPU_VAR(var)        %__percpu_seg:var
  32 #else /* ! SMP */
  33 #define PER_CPU(var, reg)       __percpu_mov_op $var, reg
  34 #define PER_CPU_VAR(var)        var
  35 #endif  /* SMP */
  36
  37 #ifdef CONFIG_X86_64_SMP
  38 #define INIT_PER_CPU_VAR(var)  init_per_cpu__##var
  39 #else
  40 #define INIT_PER_CPU_VAR(var)  var
  41 #endif
  42
  43 #else /* ...!ASSEMBLY */
  44
  45 #include <linux/kernel.h>
  46 #include <linux/stringify.h>
  47
  48 #ifdef CONFIG_SMP
  49 #define __percpu_prefix         "%%"__stringify(__percpu_seg)":"
  50 #define __my_cpu_offset         this_cpu_read(this_cpu_off)
  51
  52 /*
  53  * Compared to the generic __my_cpu_offset version, the following
  54  * saves one instruction and avoids clobbering a temp register.
  55  */
  56 #define arch_raw_cpu_ptr(ptr)                           \
  57 ({                                                      \
  58         unsigned long tcp_ptr__;                        \
  59         asm volatile("add " __percpu_arg(1) ", %0"      \
  60                      : "=r" (tcp_ptr__)                 \
  61                      : "m" (this_cpu_off), "0" (ptr));  \
  62         (typeof(*(ptr)) __kernel __force *)tcp_ptr__;   \
  63 })
  64 #else
  65 #define __percpu_prefix         ""
  66 #endif
  67
  68 #define __percpu_arg(x)         __percpu_prefix "%" #x
  69
  70 /*
  71  * Initialized pointers to per-cpu variables needed for the boot
  72  * processor need to use these macros to get the proper address
  73  * offset from __per_cpu_load on SMP.
  74  *
  75  * There also must be an entry in vmlinux_64.lds.S
  76  */
  77 #define DECLARE_INIT_PER_CPU(var) \
  78        extern typeof(var) init_per_cpu_var(var)
  79
  80 #ifdef CONFIG_X86_64_SMP
  81 #define init_per_cpu_var(var)  init_per_cpu__##var
  82 #else
  83 #define init_per_cpu_var(var)  var
  84 #endif
  85
  86 /* For arch-specific code, we can use direct single-insn ops (they
  87  * don't give an lvalue though). */
  88 extern void __bad_percpu_size(void);
  89
  90 #define percpu_to_op(op, var, val)                      \
  91 do {                                                    \
  92         typedef typeof(var) pto_T__;                    \
  93         if (0) {                                        \
  94                 pto_T__ pto_tmp__;                      \
  95                 pto_tmp__ = (val);                      \
  96                 (void)pto_tmp__;                        \
  97         }                                               \
  98         switch (sizeof(var)) {                          \
  99         case 1:                                         \
 100                 asm(op "b %1,"__percpu_arg(0)           \
 101                     : "+m" (var)                        \
 102                     : "qi" ((pto_T__)(val)));           \
 103                 break;                                  \
 104         case 2:                                         \
 105                 asm(op "w %1,"__percpu_arg(0)           \
 106                     : "+m" (var)                        \
 107                     : "ri" ((pto_T__)(val)));           \
 108                 break;                                  \
 109         case 4:                                         \
 110                 asm(op "l %1,"__percpu_arg(0)           \
 111                     : "+m" (var)                        \
 112                     : "ri" ((pto_T__)(val)));           \
 113                 break;                                  \
 114         case 8:                                         \
 115                 asm(op "q %1,"__percpu_arg(0)           \
 116                     : "+m" (var)                        \
 117                     : "re" ((pto_T__)(val)));           \
 118                 break;                                  \
 119         default: __bad_percpu_size();                   \
 120         }                                               \
 121 } while (0)
 122
 123 /*
 124  * Generate a percpu add to memory instruction and optimize code
 125  * if one is added or subtracted.
 126  */
 127 #define percpu_add_op(var, val)                                         \
 128 do {                                                                    \
 129         typedef typeof(var) pao_T__;                                    \
 130         const int pao_ID__ = (__builtin_constant_p(val) &&              \
 131                               ((val) == 1 || (val) == -1)) ?            \
 132                                 (int)(val) : 0;                         \
 133         if (0) {                                                        \
 134                 pao_T__ pao_tmp__;                                      \
 135                 pao_tmp__ = (val);                                      \
 136                 (void)pao_tmp__;                                        \
 137         }                                                               \
 138         switch (sizeof(var)) {                                          \
 139         case 1:                                                         \
 140                 if (pao_ID__ == 1)                                      \
 141                         asm("incb "__percpu_arg(0) : "+m" (var));       \
 142                 else if (pao_ID__ == -1)                                \
 143                         asm("decb "__percpu_arg(0) : "+m" (var));       \
 144                 else                                                    \
 145                         asm("addb %1, "__percpu_arg(0)                  \
 146                             : "+m" (var)                                \
 147                             : "qi" ((pao_T__)(val)));                   \
 148                 break;                                                  \
 149         case 2:                                                         \
 150                 if (pao_ID__ == 1)                                      \
 151                         asm("incw "__percpu_arg(0) : "+m" (var));       \
 152                 else if (pao_ID__ == -1)                                \
 153                         asm("decw "__percpu_arg(0) : "+m" (var));       \
 154                 else                                                    \
 155                         asm("addw %1, "__percpu_arg(0)                  \
 156                             : "+m" (var)                                \
 157                             : "ri" ((pao_T__)(val)));                   \
 158                 break;                                                  \
 159         case 4:                                                         \
 160                 if (pao_ID__ == 1)                                      \
 161                         asm("incl "__percpu_arg(0) : "+m" (var));       \
 162                 else if (pao_ID__ == -1)                                \
 163                         asm("decl "__percpu_arg(0) : "+m" (var));       \
 164                 else                                                    \
 165                         asm("addl %1, "__percpu_arg(0)                  \
 166                             : "+m" (var)                                \
 167                             : "ri" ((pao_T__)(val)));                   \
 168                 break;                                                  \
 169         case 8:                                                         \
 170                 if (pao_ID__ == 1)                                      \
 171                         asm("incq "__percpu_arg(0) : "+m" (var));       \
 172                 else if (pao_ID__ == -1)                                \
 173                         asm("decq "__percpu_arg(0) : "+m" (var));       \
 174                 else                                                    \
 175                         asm("addq %1, "__percpu_arg(0)                  \
 176                             : "+m" (var)                                \
 177                             : "re" ((pao_T__)(val)));                   \
 178                 break;                                                  \
 179         default: __bad_percpu_size();                                   \
 180         }                                                               \
 181 } while (0)
 182
 183 #define percpu_from_op(op, var)                         \
 184 ({                                                      \
 185         typeof(var) pfo_ret__;                          \
 186         switch (sizeof(var)) {                          \
 187         case 1:                                         \
 188                 asm(op "b "__percpu_arg(1)",%0"         \
 189                     : "=q" (pfo_ret__)                  \
 190                     : "m" (var));                       \
 191                 break;                                  \
 192         case 2:                                         \
 193                 asm(op "w "__percpu_arg(1)",%0"         \
 194                     : "=r" (pfo_ret__)                  \
 195                     : "m" (var));                       \
 196                 break;                                  \
 197         case 4:                                         \
 198                 asm(op "l "__percpu_arg(1)",%0"         \
 199                     : "=r" (pfo_ret__)                  \
 200                     : "m" (var));                       \
 201                 break;                                  \
 202         case 8:                                         \
 203                 asm(op "q "__percpu_arg(1)",%0"         \
 204                     : "=r" (pfo_ret__)                  \
 205                     : "m" (var));                       \
 206                 break;                                  \
 207         default: __bad_percpu_size();                   \
 208         }                                               \
 209         pfo_ret__;                                      \
 210 })
 211
 212 #define percpu_stable_op(op, var)                       \
 213 ({                                                      \
 214         typeof(var) pfo_ret__;                          \
 215         switch (sizeof(var)) {                          \
 216         case 1:                                         \
 217                 asm(op "b "__percpu_arg(P1)",%0"        \
 218                     : "=q" (pfo_ret__)                  \
 219                     : "p" (&(var)));                    \
 220                 break;                                  \
 221         case 2:                                         \
 222                 asm(op "w "__percpu_arg(P1)",%0"        \
 223                     : "=r" (pfo_ret__)                  \
 224                     : "p" (&(var)));                    \
 225                 break;                                  \
 226         case 4:                                         \
 227                 asm(op "l "__percpu_arg(P1)",%0"        \
 228                     : "=r" (pfo_ret__)                  \
 229                     : "p" (&(var)));                    \
 230                 break;                                  \
 231         case 8:                                         \
 232                 asm(op "q "__percpu_arg(P1)",%0"        \
 233                     : "=r" (pfo_ret__)                  \
 234                     : "p" (&(var)));                    \
 235                 break;                                  \
 236         default: __bad_percpu_size();                   \
 237         }                                               \
 238         pfo_ret__;                                      \
 239 })
 240
 241 #define percpu_unary_op(op, var)                        \
 242 ({                                                      \
 243         switch (sizeof(var)) {                          \
 244         case 1:                                         \
 245                 asm(op "b "__percpu_arg(0)              \
 246                     : "+m" (var));                      \
 247                 break;                                  \
 248         case 2:                                         \
 249                 asm(op "w "__percpu_arg(0)              \
 250                     : "+m" (var));                      \
 251                 break;                                  \
 252         case 4:                                         \
 253                 asm(op "l "__percpu_arg(0)              \
 254                     : "+m" (var));                      \
 255                 break;                                  \
 256         case 8:                                         \
 257                 asm(op "q "__percpu_arg(0)              \
 258                     : "+m" (var));                      \
 259                 break;                                  \
 260         default: __bad_percpu_size();                   \
 261         }                                               \
 262 })
 263
 264 /*
 265  * Add return operation
 266  */
 267 #define percpu_add_return_op(var, val)                                  \
 268 ({                                                                      \
 269         typeof(var) paro_ret__ = val;                                   \
 270         switch (sizeof(var)) {                                          \
 271         case 1:                                                         \
 272                 asm("xaddb %0, "__percpu_arg(1)                         \
 273                             : "+q" (paro_ret__), "+m" (var)             \
 274                             : : "memory");                              \
 275                 break;                                                  \
 276         case 2:                                                         \
 277                 asm("xaddw %0, "__percpu_arg(1)                         \
 278                             : "+r" (paro_ret__), "+m" (var)             \
 279                             : : "memory");                              \
 280                 break;                                                  \
 281         case 4:                                                         \
 282                 asm("xaddl %0, "__percpu_arg(1)                         \
 283                             : "+r" (paro_ret__), "+m" (var)             \
 284                             : : "memory");                              \
 285                 break;                                                  \
 286         case 8:                                                         \
 287                 asm("xaddq %0, "__percpu_arg(1)                         \
 288                             : "+re" (paro_ret__), "+m" (var)            \
 289                             : : "memory");                              \
 290                 break;                                                  \
 291         default: __bad_percpu_size();                                   \
 292         }                                                               \
 293         paro_ret__ += val;                                              \
 294         paro_ret__;                                                     \
 295 })
 296
 297 /*
 298  * xchg is implemented using cmpxchg without a lock prefix. xchg is
 299  * expensive due to the implied lock prefix.  The processor cannot prefetch
 300  * cachelines if xchg is used.
 301  */
 302 #define percpu_xchg_op(var, nval)                                       \
 303 ({                                                                      \
 304         typeof(var) pxo_ret__;                                          \
 305         typeof(var) pxo_new__ = (nval);                                 \
 306         switch (sizeof(var)) {                                          \
 307         case 1:                                                         \
 308                 asm("\n\tmov "__percpu_arg(1)",%%al"                    \
 309                     "\n1:\tcmpxchgb %2, "__percpu_arg(1)                \
 310                     "\n\tjnz 1b"                                        \
 311                             : "=&a" (pxo_ret__), "+m" (var)             \
 312                             : "q" (pxo_new__)                           \
 313                             : "memory");                                \
 314                 break;                                                  \
 315         case 2:                                                         \
 316                 asm("\n\tmov "__percpu_arg(1)",%%ax"                    \
 317                     "\n1:\tcmpxchgw %2, "__percpu_arg(1)                \
 318                     "\n\tjnz 1b"                                        \
 319                             : "=&a" (pxo_ret__), "+m" (var)             \
 320                             : "r" (pxo_new__)                           \
 321                             : "memory");                                \
 322                 break;                                                  \
 323         case 4:                                                         \
 324                 asm("\n\tmov "__percpu_arg(1)",%%eax"                   \
 325                     "\n1:\tcmpxchgl %2, "__percpu_arg(1)                \
 326                     "\n\tjnz 1b"                                        \
 327                             : "=&a" (pxo_ret__), "+m" (var)             \
 328                             : "r" (pxo_new__)                           \
 329                             : "memory");                                \
 330                 break;                                                  \
 331         case 8:                                                         \
 332                 asm("\n\tmov "__percpu_arg(1)",%%rax"                   \
 333                     "\n1:\tcmpxchgq %2, "__percpu_arg(1)                \
 334                     "\n\tjnz 1b"                                        \
 335                             : "=&a" (pxo_ret__), "+m" (var)             \
 336                             : "r" (pxo_new__)                           \
 337                             : "memory");                                \
 338                 break;                                                  \
 339         default: __bad_percpu_size();                                   \
 340         }                                                               \
 341         pxo_ret__;                                                      \
 342 })
 343
 344 /*
 345  * cmpxchg has no such implied lock semantics as a result it is much
 346  * more efficient for cpu local operations.
 347  */
 348 #define percpu_cmpxchg_op(var, oval, nval)                              \
 349 ({                                                                      \
 350         typeof(var) pco_ret__;                                          \
 351         typeof(var) pco_old__ = (oval);                                 \
 352         typeof(var) pco_new__ = (nval);                                 \
 353         switch (sizeof(var)) {                                          \
 354         case 1:                                                         \
 355                 asm("cmpxchgb %2, "__percpu_arg(1)                      \
 356                             : "=a" (pco_ret__), "+m" (var)              \
 357                             : "q" (pco_new__), "0" (pco_old__)          \
 358                             : "memory");                                \
 359                 break;                                                  \
 360         case 2:                                                         \
 361                 asm("cmpxchgw %2, "__percpu_arg(1)                      \
 362                             : "=a" (pco_ret__), "+m" (var)              \
 363                             : "r" (pco_new__), "0" (pco_old__)          \
 364                             : "memory");                                \
 365                 break;                                                  \
 366         case 4:                                                         \
 367                 asm("cmpxchgl %2, "__percpu_arg(1)                      \
 368                             : "=a" (pco_ret__), "+m" (var)              \
 369                             : "r" (pco_new__), "0" (pco_old__)          \
 370                             : "memory");                                \
 371                 break;                                                  \
 372         case 8:                                                         \
 373                 asm("cmpxchgq %2, "__percpu_arg(1)                      \
 374                             : "=a" (pco_ret__), "+m" (var)              \
 375                             : "r" (pco_new__), "0" (pco_old__)          \
 376                             : "memory");                                \
 377                 break;                                                  \
 378         default: __bad_percpu_size();                                   \
 379         }                                                               \
 380         pco_ret__;                                                      \
 381 })
 382
 383 /*
 384  * this_cpu_read() makes gcc load the percpu variable every time it is
 385  * accessed while this_cpu_read_stable() allows the value to be cached.
 386  * this_cpu_read_stable() is more efficient and can be used if its value
 387  * is guaranteed to be valid across cpus.  The current users include
 388  * get_current() and get_thread_info() both of which are actually
 389  * per-thread variables implemented as per-cpu variables and thus
 390  * stable for the duration of the respective task.
 391  */
 392 #define this_cpu_read_stable(var)       percpu_stable_op("mov", var)
 393
 394 #define raw_cpu_read_1(pcp)             percpu_from_op("mov", pcp)
 395 #define raw_cpu_read_2(pcp)             percpu_from_op("mov", pcp)
 396 #define raw_cpu_read_4(pcp)             percpu_from_op("mov", pcp)
 397
 398 #define raw_cpu_write_1(pcp, val)       percpu_to_op("mov", (pcp), val)
 399 #define raw_cpu_write_2(pcp, val)       percpu_to_op("mov", (pcp), val)
 400 #define raw_cpu_write_4(pcp, val)       percpu_to_op("mov", (pcp), val)
 401 #define raw_cpu_add_1(pcp, val)         percpu_add_op((pcp), val)
 402 #define raw_cpu_add_2(pcp, val)         percpu_add_op((pcp), val)
 403 #define raw_cpu_add_4(pcp, val)         percpu_add_op((pcp), val)
 404 #define raw_cpu_and_1(pcp, val)         percpu_to_op("and", (pcp), val)
 405 #define raw_cpu_and_2(pcp, val)         percpu_to_op("and", (pcp), val)
 406 #define raw_cpu_and_4(pcp, val)         percpu_to_op("and", (pcp), val)
 407 #define raw_cpu_or_1(pcp, val)          percpu_to_op("or", (pcp), val)
 408 #define raw_cpu_or_2(pcp, val)          percpu_to_op("or", (pcp), val)
 409 #define raw_cpu_or_4(pcp, val)          percpu_to_op("or", (pcp), val)
 410 #define raw_cpu_xchg_1(pcp, val)        percpu_xchg_op(pcp, val)
 411 #define raw_cpu_xchg_2(pcp, val)        percpu_xchg_op(pcp, val)
 412 #define raw_cpu_xchg_4(pcp, val)        percpu_xchg_op(pcp, val)
 413
 414 #define this_cpu_read_1(pcp)            percpu_from_op("mov", pcp)
 415 #define this_cpu_read_2(pcp)            percpu_from_op("mov", pcp)
 416 #define this_cpu_read_4(pcp)            percpu_from_op("mov", pcp)
 417 #define this_cpu_write_1(pcp, val)      percpu_to_op("mov", (pcp), val)
 418 #define this_cpu_write_2(pcp, val)      percpu_to_op("mov", (pcp), val)
 419 #define this_cpu_write_4(pcp, val)      percpu_to_op("mov", (pcp), val)
 420 #define this_cpu_add_1(pcp, val)        percpu_add_op((pcp), val)
 421 #define this_cpu_add_2(pcp, val)        percpu_add_op((pcp), val)
 422 #define this_cpu_add_4(pcp, val)        percpu_add_op((pcp), val)
 423 #define this_cpu_and_1(pcp, val)        percpu_to_op("and", (pcp), val)
 424 #define this_cpu_and_2(pcp, val)        percpu_to_op("and", (pcp), val)
 425 #define this_cpu_and_4(pcp, val)        percpu_to_op("and", (pcp), val)
 426 #define this_cpu_or_1(pcp, val)         percpu_to_op("or", (pcp), val)
 427 #define this_cpu_or_2(pcp, val)         percpu_to_op("or", (pcp), val)
 428 #define this_cpu_or_4(pcp, val)         percpu_to_op("or", (pcp), val)
 429 #define this_cpu_xchg_1(pcp, nval)      percpu_xchg_op(pcp, nval)
 430 #define this_cpu_xchg_2(pcp, nval)      percpu_xchg_op(pcp, nval)
 431 #define this_cpu_xchg_4(pcp, nval)      percpu_xchg_op(pcp, nval)
 432
 433 #define raw_cpu_add_return_1(pcp, val)          percpu_add_return_op(pcp, val)
 434 #define raw_cpu_add_return_2(pcp, val)          percpu_add_return_op(pcp, val)
 435 #define raw_cpu_add_return_4(pcp, val)          percpu_add_return_op(pcp, val)
 436 #define raw_cpu_cmpxchg_1(pcp, oval, nval)      percpu_cmpxchg_op(pcp, oval, nval)
 437 #define raw_cpu_cmpxchg_2(pcp, oval, nval)      percpu_cmpxchg_op(pcp, oval, nval)
 438 #define raw_cpu_cmpxchg_4(pcp, oval, nval)      percpu_cmpxchg_op(pcp, oval, nval)
 439
 440 #define this_cpu_add_return_1(pcp, val)         percpu_add_return_op(pcp, val)
 441 #define this_cpu_add_return_2(pcp, val)         percpu_add_return_op(pcp, val)
 442 #define this_cpu_add_return_4(pcp, val)         percpu_add_return_op(pcp, val)
 443 #define this_cpu_cmpxchg_1(pcp, oval, nval)     percpu_cmpxchg_op(pcp, oval, nval)
 444 #define this_cpu_cmpxchg_2(pcp, oval, nval)     percpu_cmpxchg_op(pcp, oval, nval)
 445 #define this_cpu_cmpxchg_4(pcp, oval, nval)     percpu_cmpxchg_op(pcp, oval, nval)
 446
 447 #ifdef CONFIG_X86_CMPXCHG64
 448 #define percpu_cmpxchg8b_double(pcp1, pcp2, o1, o2, n1, n2)             \
 449 ({                                                                      \
 450         bool __ret;                                                     \
 451         typeof(pcp1) __o1 = (o1), __n1 = (n1);                          \
 452         typeof(pcp2) __o2 = (o2), __n2 = (n2);                          \
 453         asm volatile("cmpxchg8b "__percpu_arg(1)"\n\tsetz %0\n\t"       \
 454                     : "=a" (__ret), "+m" (pcp1), "+m" (pcp2), "+d" (__o2) \
 455                     :  "b" (__n1), "c" (__n2), "a" (__o1));             \
 456         __ret;                                                          \
 457 })
 458
 459 #define raw_cpu_cmpxchg_double_4        percpu_cmpxchg8b_double
 460 #define this_cpu_cmpxchg_double_4       percpu_cmpxchg8b_double
 461 #endif /* CONFIG_X86_CMPXCHG64 */
 462
 463 /*
 464  * Per cpu atomic 64 bit operations are only available under 64 bit.
 465  * 32 bit must fall back to generic operations.
 466  */
 467 #ifdef CONFIG_X86_64
 468 #define raw_cpu_read_8(pcp)                     percpu_from_op("mov", pcp)
 469 #define raw_cpu_write_8(pcp, val)               percpu_to_op("mov", (pcp), val)
 470 #define raw_cpu_add_8(pcp, val)                 percpu_add_op((pcp), val)
 471 #define raw_cpu_and_8(pcp, val)                 percpu_to_op("and", (pcp), val)
 472 #define raw_cpu_or_8(pcp, val)                  percpu_to_op("or", (pcp), val)
 473 #define raw_cpu_add_return_8(pcp, val)          percpu_add_return_op(pcp, val)
 474 #define raw_cpu_xchg_8(pcp, nval)               percpu_xchg_op(pcp, nval)
 475 #define raw_cpu_cmpxchg_8(pcp, oval, nval)      percpu_cmpxchg_op(pcp, oval, nval)
 476
 477 #define this_cpu_read_8(pcp)                    percpu_from_op("mov", pcp)
 478 #define this_cpu_write_8(pcp, val)              percpu_to_op("mov", (pcp), val)
 479 #define this_cpu_add_8(pcp, val)                percpu_add_op((pcp), val)
 480 #define this_cpu_and_8(pcp, val)                percpu_to_op("and", (pcp), val)
 481 #define this_cpu_or_8(pcp, val)                 percpu_to_op("or", (pcp), val)
 482 #define this_cpu_add_return_8(pcp, val)         percpu_add_return_op(pcp, val)
 483 #define this_cpu_xchg_8(pcp, nval)              percpu_xchg_op(pcp, nval)
 484 #define this_cpu_cmpxchg_8(pcp, oval, nval)     percpu_cmpxchg_op(pcp, oval, nval)
 485
 486 /*
 487  * Pretty complex macro to generate cmpxchg16 instruction.  The instruction
 488  * is not supported on early AMD64 processors so we must be able to emulate
 489  * it in software.  The address used in the cmpxchg16 instruction must be
 490  * aligned to a 16 byte boundary.
 491  */
 492 #define percpu_cmpxchg16b_double(pcp1, pcp2, o1, o2, n1, n2)            \
 493 ({                                                                      \
 494         bool __ret;                                                     \
 495         typeof(pcp1) __o1 = (o1), __n1 = (n1);                          \
 496         typeof(pcp2) __o2 = (o2), __n2 = (n2);                          \
 497         alternative_io("leaq %P1,%%rsi\n\tcall this_cpu_cmpxchg16b_emu\n\t", \
 498                        "cmpxchg16b " __percpu_arg(1) "\n\tsetz %0\n\t", \
 499                        X86_FEATURE_CX16,                                \
 500                        ASM_OUTPUT2("=a" (__ret), "+m" (pcp1),           \
 501                                    "+m" (pcp2), "+d" (__o2)),           \
 502                        "b" (__n1), "c" (__n2), "a" (__o1) : "rsi");     \
 503         __ret;                                                          \
 504 })
 505
 506 #define raw_cpu_cmpxchg_double_8        percpu_cmpxchg16b_double
 507 #define this_cpu_cmpxchg_double_8       percpu_cmpxchg16b_double
 508
 509 #endif
 510
 511 static __always_inline bool x86_this_cpu_constant_test_bit(unsigned int nr,
 512                         const unsigned long __percpu *addr)
 513 {
 514         unsigned long __percpu *a =
 515                 (unsigned long __percpu *)addr + nr / BITS_PER_LONG;
 516
 517 #ifdef CONFIG_X86_64
 518         return ((1UL << (nr % BITS_PER_LONG)) & raw_cpu_read_8(*a)) != 0;
 519 #else
 520         return ((1UL << (nr % BITS_PER_LONG)) & raw_cpu_read_4(*a)) != 0;
 521 #endif
 522 }
 523
 524 static inline bool x86_this_cpu_variable_test_bit(int nr,
 525                         const unsigned long __percpu *addr)
 526 {
 527         bool oldbit;
 528
 529         asm volatile("bt "__percpu_arg(2)",%1\n\t"
 530                         CC_SET(c)
 531                         : CC_OUT(c) (oldbit)
 532                         : "m" (*(unsigned long __percpu *)addr), "Ir" (nr));
 533
 534         return oldbit;
 535 }
 536
 537 #define x86_this_cpu_test_bit(nr, addr)                 \
 538         (__builtin_constant_p((nr))                     \
 539          ? x86_this_cpu_constant_test_bit((nr), (addr)) \
 540          : x86_this_cpu_variable_test_bit((nr), (addr)))
 541
 542
 543 #include <asm-generic/percpu.h>
 544
 545 /* We can use this directly for local CPU (faster). */
 546 DECLARE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off);
 547
 548 #endif /* !__ASSEMBLY__ */
 549
 550 #ifdef CONFIG_SMP
 551
 552 /*
 553  * Define the "EARLY_PER_CPU" macros.  These are used for some per_cpu
 554  * variables that are initialized and accessed before there are per_cpu
 555  * areas allocated.
 556  */
 557
 558 #define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)                  \
 559         DEFINE_PER_CPU(_type, _name) = _initvalue;                      \
 560         __typeof__(_type) _name##_early_map[NR_CPUS] __initdata =       \
 561                                 { [0 ... NR_CPUS-1] = _initvalue };     \
 562         __typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
 563
 564 #define DEFINE_EARLY_PER_CPU_READ_MOSTLY(_type, _name, _initvalue)      \
 565         DEFINE_PER_CPU_READ_MOSTLY(_type, _name) = _initvalue;          \
 566         __typeof__(_type) _name##_early_map[NR_CPUS] __initdata =       \
 567                                 { [0 ... NR_CPUS-1] = _initvalue };     \
 568         __typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
 569
 570 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name)                      \
 571         EXPORT_PER_CPU_SYMBOL(_name)
 572
 573 #define DECLARE_EARLY_PER_CPU(_type, _name)                     \
 574         DECLARE_PER_CPU(_type, _name);                          \
 575         extern __typeof__(_type) *_name##_early_ptr;            \
 576         extern __typeof__(_type)  _name##_early_map[]
 577
 578 #define DECLARE_EARLY_PER_CPU_READ_MOSTLY(_type, _name)         \
 579         DECLARE_PER_CPU_READ_MOSTLY(_type, _name);              \
 580         extern __typeof__(_type) *_name##_early_ptr;            \
 581         extern __typeof__(_type)  _name##_early_map[]
 582
 583 #define early_per_cpu_ptr(_name) (_name##_early_ptr)
 584 #define early_per_cpu_map(_name, _idx) (_name##_early_map[_idx])
 585 #define early_per_cpu(_name, _cpu)                              \
 586         *(early_per_cpu_ptr(_name) ?                            \
 587                 &early_per_cpu_ptr(_name)[_cpu] :               \
 588                 &per_cpu(_name, _cpu))
 589
 590 #else   /* !CONFIG_SMP */
 591 #define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)          \
 592         DEFINE_PER_CPU(_type, _name) = _initvalue
 593
 594 #define DEFINE_EARLY_PER_CPU_READ_MOSTLY(_type, _name, _initvalue)      \
 595         DEFINE_PER_CPU_READ_MOSTLY(_type, _name) = _initvalue
 596
 597 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name)                      \
 598         EXPORT_PER_CPU_SYMBOL(_name)
 599
 600 #define DECLARE_EARLY_PER_CPU(_type, _name)                     \
 601         DECLARE_PER_CPU(_type, _name)
 602
 603 #define DECLARE_EARLY_PER_CPU_READ_MOSTLY(_type, _name)         \
 604         DECLARE_PER_CPU_READ_MOSTLY(_type, _name)
 605
 606 #define early_per_cpu(_name, _cpu) per_cpu(_name, _cpu)
 607 #define early_per_cpu_ptr(_name) NULL
 608 /* no early_per_cpu_map() */
 609
 610 #endif  /* !CONFIG_SMP */
 611
 612 #endif /* _ASM_X86_PERCPU_H */