arch/x86/include/asm/percpu.h

   1 #ifndef _ASM_X86_PERCPU_H
   2 #define _ASM_X86_PERCPU_H
   3
   4 #ifdef CONFIG_X86_64
   5 #define __percpu_seg            gs
   6 #define __percpu_mov_op         movq
   7 #else
   8 #define __percpu_seg            fs
   9 #define __percpu_mov_op         movl
  10 #endif
  11
  12 #ifdef __ASSEMBLY__
  13
  14 /*
  15  * PER_CPU finds an address of a per-cpu variable.
  16  *
  17  * Args:
  18  *    var - variable name
  19  *    reg - 32bit register
  20  *
  21  * The resulting address is stored in the "reg" argument.
  22  *
  23  * Example:
  24  *    PER_CPU(cpu_gdt_descr, %ebx)
  25  */
  26 #ifdef CONFIG_SMP
  27 #define PER_CPU(var, reg)                                               \
  28         __percpu_mov_op %__percpu_seg:this_cpu_off, reg;                \
  29         lea var(reg), reg
  30 #define PER_CPU_VAR(var)        %__percpu_seg:var
  31 #else /* ! SMP */
  32 #define PER_CPU(var, reg)       __percpu_mov_op $var, reg
  33 #define PER_CPU_VAR(var)        var
  34 #endif  /* SMP */
  35
  36 #ifdef CONFIG_X86_64_SMP
  37 #define INIT_PER_CPU_VAR(var)  init_per_cpu__##var
  38 #else
  39 #define INIT_PER_CPU_VAR(var)  var
  40 #endif
  41
  42 #else /* ...!ASSEMBLY */
  43
  44 #include <linux/kernel.h>
  45 #include <linux/stringify.h>
  46
  47 #ifdef CONFIG_SMP
  48 #define __percpu_prefix         "%%"__stringify(__percpu_seg)":"
  49 #define __my_cpu_offset         this_cpu_read(this_cpu_off)
  50
  51 /*
  52  * Compared to the generic __my_cpu_offset version, the following
  53  * saves one instruction and avoids clobbering a temp register.
  54  */
  55 #define __this_cpu_ptr(ptr)                             \
  56 ({                                                      \
  57         unsigned long tcp_ptr__;                        \
  58         __verify_pcpu_ptr(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 "%P" #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, constraint)             \
 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                     : constraint);                      \
 191                 break;                                  \
 192         case 2:                                         \
 193                 asm(op "w "__percpu_arg(1)",%0"         \
 194                     : "=r" (pfo_ret__)                  \
 195                     : constraint);                      \
 196                 break;                                  \
 197         case 4:                                         \
 198                 asm(op "l "__percpu_arg(1)",%0"         \
 199                     : "=r" (pfo_ret__)                  \
 200                     : constraint);                      \
 201                 break;                                  \
 202         case 8:                                         \
 203                 asm(op "q "__percpu_arg(1)",%0"         \
 204                     : "=r" (pfo_ret__)                  \
 205                     : constraint);                      \
 206                 break;                                  \
 207         default: __bad_percpu_size();                   \
 208         }                                               \
 209         pfo_ret__;                                      \
 210 })
 211
 212 #define percpu_unary_op(op, var)                        \
 213 ({                                                      \
 214         switch (sizeof(var)) {                          \
 215         case 1:                                         \
 216                 asm(op "b "__percpu_arg(0)              \
 217                     : "+m" (var));                      \
 218                 break;                                  \
 219         case 2:                                         \
 220                 asm(op "w "__percpu_arg(0)              \
 221                     : "+m" (var));                      \
 222                 break;                                  \
 223         case 4:                                         \
 224                 asm(op "l "__percpu_arg(0)              \
 225                     : "+m" (var));                      \
 226                 break;                                  \
 227         case 8:                                         \
 228                 asm(op "q "__percpu_arg(0)              \
 229                     : "+m" (var));                      \
 230                 break;                                  \
 231         default: __bad_percpu_size();                   \
 232         }                                               \
 233 })
 234
 235 /*
 236  * Add return operation
 237  */
 238 #define percpu_add_return_op(var, val)                                  \
 239 ({                                                                      \
 240         typeof(var) paro_ret__ = val;                                   \
 241         switch (sizeof(var)) {                                          \
 242         case 1:                                                         \
 243                 asm("xaddb %0, "__percpu_arg(1)                         \
 244                             : "+q" (paro_ret__), "+m" (var)             \
 245                             : : "memory");                              \
 246                 break;                                                  \
 247         case 2:                                                         \
 248                 asm("xaddw %0, "__percpu_arg(1)                         \
 249                             : "+r" (paro_ret__), "+m" (var)             \
 250                             : : "memory");                              \
 251                 break;                                                  \
 252         case 4:                                                         \
 253                 asm("xaddl %0, "__percpu_arg(1)                         \
 254                             : "+r" (paro_ret__), "+m" (var)             \
 255                             : : "memory");                              \
 256                 break;                                                  \
 257         case 8:                                                         \
 258                 asm("xaddq %0, "__percpu_arg(1)                         \
 259                             : "+re" (paro_ret__), "+m" (var)            \
 260                             : : "memory");                              \
 261                 break;                                                  \
 262         default: __bad_percpu_size();                                   \
 263         }                                                               \
 264         paro_ret__ += val;                                              \
 265         paro_ret__;                                                     \
 266 })
 267
 268 /*
 269  * xchg is implemented using cmpxchg without a lock prefix. xchg is
 270  * expensive due to the implied lock prefix.  The processor cannot prefetch
 271  * cachelines if xchg is used.
 272  */
 273 #define percpu_xchg_op(var, nval)                                       \
 274 ({                                                                      \
 275         typeof(var) pxo_ret__;                                          \
 276         typeof(var) pxo_new__ = (nval);                                 \
 277         switch (sizeof(var)) {                                          \
 278         case 1:                                                         \
 279                 asm("\n\tmov "__percpu_arg(1)",%%al"                    \
 280                     "\n1:\tcmpxchgb %2, "__percpu_arg(1)                \
 281                     "\n\tjnz 1b"                                        \
 282                             : "=&a" (pxo_ret__), "+m" (var)             \
 283                             : "q" (pxo_new__)                           \
 284                             : "memory");                                \
 285                 break;                                                  \
 286         case 2:                                                         \
 287                 asm("\n\tmov "__percpu_arg(1)",%%ax"                    \
 288                     "\n1:\tcmpxchgw %2, "__percpu_arg(1)                \
 289                     "\n\tjnz 1b"                                        \
 290                             : "=&a" (pxo_ret__), "+m" (var)             \
 291                             : "r" (pxo_new__)                           \
 292                             : "memory");                                \
 293                 break;                                                  \
 294         case 4:                                                         \
 295                 asm("\n\tmov "__percpu_arg(1)",%%eax"                   \
 296                     "\n1:\tcmpxchgl %2, "__percpu_arg(1)                \
 297                     "\n\tjnz 1b"                                        \
 298                             : "=&a" (pxo_ret__), "+m" (var)             \
 299                             : "r" (pxo_new__)                           \
 300                             : "memory");                                \
 301                 break;                                                  \
 302         case 8:                                                         \
 303                 asm("\n\tmov "__percpu_arg(1)",%%rax"                   \
 304                     "\n1:\tcmpxchgq %2, "__percpu_arg(1)                \
 305                     "\n\tjnz 1b"                                        \
 306                             : "=&a" (pxo_ret__), "+m" (var)             \
 307                             : "r" (pxo_new__)                           \
 308                             : "memory");                                \
 309                 break;                                                  \
 310         default: __bad_percpu_size();                                   \
 311         }                                                               \
 312         pxo_ret__;                                                      \
 313 })
 314
 315 /*
 316  * cmpxchg has no such implied lock semantics as a result it is much
 317  * more efficient for cpu local operations.
 318  */
 319 #define percpu_cmpxchg_op(var, oval, nval)                              \
 320 ({                                                                      \
 321         typeof(var) pco_ret__;                                          \
 322         typeof(var) pco_old__ = (oval);                                 \
 323         typeof(var) pco_new__ = (nval);                                 \
 324         switch (sizeof(var)) {                                          \
 325         case 1:                                                         \
 326                 asm("cmpxchgb %2, "__percpu_arg(1)                      \
 327                             : "=a" (pco_ret__), "+m" (var)              \
 328                             : "q" (pco_new__), "0" (pco_old__)          \
 329                             : "memory");                                \
 330                 break;                                                  \
 331         case 2:                                                         \
 332                 asm("cmpxchgw %2, "__percpu_arg(1)                      \
 333                             : "=a" (pco_ret__), "+m" (var)              \
 334                             : "r" (pco_new__), "0" (pco_old__)          \
 335                             : "memory");                                \
 336                 break;                                                  \
 337         case 4:                                                         \
 338                 asm("cmpxchgl %2, "__percpu_arg(1)                      \
 339                             : "=a" (pco_ret__), "+m" (var)              \
 340                             : "r" (pco_new__), "0" (pco_old__)          \
 341                             : "memory");                                \
 342                 break;                                                  \
 343         case 8:                                                         \
 344                 asm("cmpxchgq %2, "__percpu_arg(1)                      \
 345                             : "=a" (pco_ret__), "+m" (var)              \
 346                             : "r" (pco_new__), "0" (pco_old__)          \
 347                             : "memory");                                \
 348                 break;                                                  \
 349         default: __bad_percpu_size();                                   \
 350         }                                                               \
 351         pco_ret__;                                                      \
 352 })
 353
 354 /*
 355  * this_cpu_read() makes gcc load the percpu variable every time it is
 356  * accessed while this_cpu_read_stable() allows the value to be cached.
 357  * this_cpu_read_stable() is more efficient and can be used if its value
 358  * is guaranteed to be valid across cpus.  The current users include
 359  * get_current() and get_thread_info() both of which are actually
 360  * per-thread variables implemented as per-cpu variables and thus
 361  * stable for the duration of the respective task.
 362  */
 363 #define this_cpu_read_stable(var)       percpu_from_op("mov", var, "p" (&(var)))
 364
 365 #define __this_cpu_read_1(pcp)          percpu_from_op("mov", (pcp), "m"(pcp))
 366 #define __this_cpu_read_2(pcp)          percpu_from_op("mov", (pcp), "m"(pcp))
 367 #define __this_cpu_read_4(pcp)          percpu_from_op("mov", (pcp), "m"(pcp))
 368
 369 #define __this_cpu_write_1(pcp, val)    percpu_to_op("mov", (pcp), val)
 370 #define __this_cpu_write_2(pcp, val)    percpu_to_op("mov", (pcp), val)
 371 #define __this_cpu_write_4(pcp, val)    percpu_to_op("mov", (pcp), val)
 372 #define __this_cpu_add_1(pcp, val)      percpu_add_op((pcp), val)
 373 #define __this_cpu_add_2(pcp, val)      percpu_add_op((pcp), val)
 374 #define __this_cpu_add_4(pcp, val)      percpu_add_op((pcp), val)
 375 #define __this_cpu_and_1(pcp, val)      percpu_to_op("and", (pcp), val)
 376 #define __this_cpu_and_2(pcp, val)      percpu_to_op("and", (pcp), val)
 377 #define __this_cpu_and_4(pcp, val)      percpu_to_op("and", (pcp), val)
 378 #define __this_cpu_or_1(pcp, val)       percpu_to_op("or", (pcp), val)
 379 #define __this_cpu_or_2(pcp, val)       percpu_to_op("or", (pcp), val)
 380 #define __this_cpu_or_4(pcp, val)       percpu_to_op("or", (pcp), val)
 381 #define __this_cpu_xchg_1(pcp, val)     percpu_xchg_op(pcp, val)
 382 #define __this_cpu_xchg_2(pcp, val)     percpu_xchg_op(pcp, val)
 383 #define __this_cpu_xchg_4(pcp, val)     percpu_xchg_op(pcp, val)
 384
 385 #define this_cpu_read_1(pcp)            percpu_from_op("mov", (pcp), "m"(pcp))
 386 #define this_cpu_read_2(pcp)            percpu_from_op("mov", (pcp), "m"(pcp))
 387 #define this_cpu_read_4(pcp)            percpu_from_op("mov", (pcp), "m"(pcp))
 388 #define this_cpu_write_1(pcp, val)      percpu_to_op("mov", (pcp), val)
 389 #define this_cpu_write_2(pcp, val)      percpu_to_op("mov", (pcp), val)
 390 #define this_cpu_write_4(pcp, val)      percpu_to_op("mov", (pcp), val)
 391 #define this_cpu_add_1(pcp, val)        percpu_add_op((pcp), val)
 392 #define this_cpu_add_2(pcp, val)        percpu_add_op((pcp), val)
 393 #define this_cpu_add_4(pcp, val)        percpu_add_op((pcp), val)
 394 #define this_cpu_and_1(pcp, val)        percpu_to_op("and", (pcp), val)
 395 #define this_cpu_and_2(pcp, val)        percpu_to_op("and", (pcp), val)
 396 #define this_cpu_and_4(pcp, val)        percpu_to_op("and", (pcp), val)
 397 #define this_cpu_or_1(pcp, val)         percpu_to_op("or", (pcp), val)
 398 #define this_cpu_or_2(pcp, val)         percpu_to_op("or", (pcp), val)
 399 #define this_cpu_or_4(pcp, val)         percpu_to_op("or", (pcp), val)
 400 #define this_cpu_xchg_1(pcp, nval)      percpu_xchg_op(pcp, nval)
 401 #define this_cpu_xchg_2(pcp, nval)      percpu_xchg_op(pcp, nval)
 402 #define this_cpu_xchg_4(pcp, nval)      percpu_xchg_op(pcp, nval)
 403
 404 #define __this_cpu_add_return_1(pcp, val) percpu_add_return_op(pcp, val)
 405 #define __this_cpu_add_return_2(pcp, val) percpu_add_return_op(pcp, val)
 406 #define __this_cpu_add_return_4(pcp, val) percpu_add_return_op(pcp, val)
 407 #define __this_cpu_cmpxchg_1(pcp, oval, nval)   percpu_cmpxchg_op(pcp, oval, nval)
 408 #define __this_cpu_cmpxchg_2(pcp, oval, nval)   percpu_cmpxchg_op(pcp, oval, nval)
 409 #define __this_cpu_cmpxchg_4(pcp, oval, nval)   percpu_cmpxchg_op(pcp, oval, nval)
 410
 411 #define this_cpu_add_return_1(pcp, val) percpu_add_return_op(pcp, val)
 412 #define this_cpu_add_return_2(pcp, val) percpu_add_return_op(pcp, val)
 413 #define this_cpu_add_return_4(pcp, val) percpu_add_return_op(pcp, val)
 414 #define this_cpu_cmpxchg_1(pcp, oval, nval)     percpu_cmpxchg_op(pcp, oval, nval)
 415 #define this_cpu_cmpxchg_2(pcp, oval, nval)     percpu_cmpxchg_op(pcp, oval, nval)
 416 #define this_cpu_cmpxchg_4(pcp, oval, nval)     percpu_cmpxchg_op(pcp, oval, nval)
 417
 418 #ifdef CONFIG_X86_CMPXCHG64
 419 #define percpu_cmpxchg8b_double(pcp1, pcp2, o1, o2, n1, n2)             \
 420 ({                                                                      \
 421         bool __ret;                                                     \
 422         typeof(pcp1) __o1 = (o1), __n1 = (n1);                          \
 423         typeof(pcp2) __o2 = (o2), __n2 = (n2);                          \
 424         asm volatile("cmpxchg8b "__percpu_arg(1)"\n\tsetz %0\n\t"       \
 425                     : "=a" (__ret), "+m" (pcp1), "+m" (pcp2), "+d" (__o2) \
 426                     :  "b" (__n1), "c" (__n2), "a" (__o1));             \
 427         __ret;                                                          \
 428 })
 429
 430 #define __this_cpu_cmpxchg_double_4     percpu_cmpxchg8b_double
 431 #define this_cpu_cmpxchg_double_4       percpu_cmpxchg8b_double
 432 #endif /* CONFIG_X86_CMPXCHG64 */
 433
 434 /*
 435  * Per cpu atomic 64 bit operations are only available under 64 bit.
 436  * 32 bit must fall back to generic operations.
 437  */
 438 #ifdef CONFIG_X86_64
 439 #define __this_cpu_read_8(pcp)          percpu_from_op("mov", (pcp), "m"(pcp))
 440 #define __this_cpu_write_8(pcp, val)    percpu_to_op("mov", (pcp), val)
 441 #define __this_cpu_add_8(pcp, val)      percpu_add_op((pcp), val)
 442 #define __this_cpu_and_8(pcp, val)      percpu_to_op("and", (pcp), val)
 443 #define __this_cpu_or_8(pcp, val)       percpu_to_op("or", (pcp), val)
 444 #define __this_cpu_add_return_8(pcp, val) percpu_add_return_op(pcp, val)
 445 #define __this_cpu_xchg_8(pcp, nval)    percpu_xchg_op(pcp, nval)
 446 #define __this_cpu_cmpxchg_8(pcp, oval, nval)   percpu_cmpxchg_op(pcp, oval, nval)
 447
 448 #define this_cpu_read_8(pcp)            percpu_from_op("mov", (pcp), "m"(pcp))
 449 #define this_cpu_write_8(pcp, val)      percpu_to_op("mov", (pcp), val)
 450 #define this_cpu_add_8(pcp, val)        percpu_add_op((pcp), val)
 451 #define this_cpu_and_8(pcp, val)        percpu_to_op("and", (pcp), val)
 452 #define this_cpu_or_8(pcp, val)         percpu_to_op("or", (pcp), val)
 453 #define this_cpu_add_return_8(pcp, val) percpu_add_return_op(pcp, val)
 454 #define this_cpu_xchg_8(pcp, nval)      percpu_xchg_op(pcp, nval)
 455 #define this_cpu_cmpxchg_8(pcp, oval, nval)     percpu_cmpxchg_op(pcp, oval, nval)
 456
 457 /*
 458  * Pretty complex macro to generate cmpxchg16 instruction.  The instruction
 459  * is not supported on early AMD64 processors so we must be able to emulate
 460  * it in software.  The address used in the cmpxchg16 instruction must be
 461  * aligned to a 16 byte boundary.
 462  */
 463 #define percpu_cmpxchg16b_double(pcp1, pcp2, o1, o2, n1, n2)            \
 464 ({                                                                      \
 465         bool __ret;                                                     \
 466         typeof(pcp1) __o1 = (o1), __n1 = (n1);                          \
 467         typeof(pcp2) __o2 = (o2), __n2 = (n2);                          \
 468         alternative_io("leaq %P1,%%rsi\n\tcall this_cpu_cmpxchg16b_emu\n\t", \
 469                        "cmpxchg16b " __percpu_arg(1) "\n\tsetz %0\n\t", \
 470                        X86_FEATURE_CX16,                                \
 471                        ASM_OUTPUT2("=a" (__ret), "+m" (pcp1),           \
 472                                    "+m" (pcp2), "+d" (__o2)),           \
 473                        "b" (__n1), "c" (__n2), "a" (__o1) : "rsi");     \
 474         __ret;                                                          \
 475 })
 476
 477 #define __this_cpu_cmpxchg_double_8     percpu_cmpxchg16b_double
 478 #define this_cpu_cmpxchg_double_8       percpu_cmpxchg16b_double
 479
 480 #endif
 481
 482 /* This is not atomic against other CPUs -- CPU preemption needs to be off */
 483 #define x86_test_and_clear_bit_percpu(bit, var)                         \
 484 ({                                                                      \
 485         int old__;                                                      \
 486         asm volatile("btr %2,"__percpu_arg(1)"\n\tsbbl %0,%0"           \
 487                      : "=r" (old__), "+m" (var)                         \
 488                      : "dIr" (bit));                                    \
 489         old__;                                                          \
 490 })
 491
 492 static __always_inline int x86_this_cpu_constant_test_bit(unsigned int nr,
 493                         const unsigned long __percpu *addr)
 494 {
 495         unsigned long __percpu *a = (unsigned long *)addr + nr / BITS_PER_LONG;
 496
 497 #ifdef CONFIG_X86_64
 498         return ((1UL << (nr % BITS_PER_LONG)) & __this_cpu_read_8(*a)) != 0;
 499 #else
 500         return ((1UL << (nr % BITS_PER_LONG)) & __this_cpu_read_4(*a)) != 0;
 501 #endif
 502 }
 503
 504 static inline int x86_this_cpu_variable_test_bit(int nr,
 505                         const unsigned long __percpu *addr)
 506 {
 507         int oldbit;
 508
 509         asm volatile("bt "__percpu_arg(2)",%1\n\t"
 510                         "sbb %0,%0"
 511                         : "=r" (oldbit)
 512                         : "m" (*(unsigned long *)addr), "Ir" (nr));
 513
 514         return oldbit;
 515 }
 516
 517 #define x86_this_cpu_test_bit(nr, addr)                 \
 518         (__builtin_constant_p((nr))                     \
 519          ? x86_this_cpu_constant_test_bit((nr), (addr)) \
 520          : x86_this_cpu_variable_test_bit((nr), (addr)))
 521
 522
 523 #include <asm-generic/percpu.h>
 524
 525 /* We can use this directly for local CPU (faster). */
 526 DECLARE_PER_CPU(unsigned long, this_cpu_off);
 527
 528 #endif /* !__ASSEMBLY__ */
 529
 530 #ifdef CONFIG_SMP
 531
 532 /*
 533  * Define the "EARLY_PER_CPU" macros.  These are used for some per_cpu
 534  * variables that are initialized and accessed before there are per_cpu
 535  * areas allocated.
 536  */
 537
 538 #define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)                  \
 539         DEFINE_PER_CPU(_type, _name) = _initvalue;                      \
 540         __typeof__(_type) _name##_early_map[NR_CPUS] __initdata =       \
 541                                 { [0 ... NR_CPUS-1] = _initvalue };     \
 542         __typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
 543
 544 #define DEFINE_EARLY_PER_CPU_READ_MOSTLY(_type, _name, _initvalue)      \
 545         DEFINE_PER_CPU_READ_MOSTLY(_type, _name) = _initvalue;          \
 546         __typeof__(_type) _name##_early_map[NR_CPUS] __initdata =       \
 547                                 { [0 ... NR_CPUS-1] = _initvalue };     \
 548         __typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
 549
 550 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name)                      \
 551         EXPORT_PER_CPU_SYMBOL(_name)
 552
 553 #define DECLARE_EARLY_PER_CPU(_type, _name)                     \
 554         DECLARE_PER_CPU(_type, _name);                          \
 555         extern __typeof__(_type) *_name##_early_ptr;            \
 556         extern __typeof__(_type)  _name##_early_map[]
 557
 558 #define DECLARE_EARLY_PER_CPU_READ_MOSTLY(_type, _name)         \
 559         DECLARE_PER_CPU_READ_MOSTLY(_type, _name);              \
 560         extern __typeof__(_type) *_name##_early_ptr;            \
 561         extern __typeof__(_type)  _name##_early_map[]
 562
 563 #define early_per_cpu_ptr(_name) (_name##_early_ptr)
 564 #define early_per_cpu_map(_name, _idx) (_name##_early_map[_idx])
 565 #define early_per_cpu(_name, _cpu)                              \
 566         *(early_per_cpu_ptr(_name) ?                            \
 567                 &early_per_cpu_ptr(_name)[_cpu] :               \
 568                 &per_cpu(_name, _cpu))
 569
 570 #else   /* !CONFIG_SMP */
 571 #define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)          \
 572         DEFINE_PER_CPU(_type, _name) = _initvalue
 573
 574 #define DEFINE_EARLY_PER_CPU_READ_MOSTLY(_type, _name, _initvalue)      \
 575         DEFINE_PER_CPU_READ_MOSTLY(_type, _name) = _initvalue
 576
 577 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name)                      \
 578         EXPORT_PER_CPU_SYMBOL(_name)
 579
 580 #define DECLARE_EARLY_PER_CPU(_type, _name)                     \
 581         DECLARE_PER_CPU(_type, _name)
 582
 583 #define DECLARE_EARLY_PER_CPU_READ_MOSTLY(_type, _name)         \
 584         DECLARE_PER_CPU_READ_MOSTLY(_type, _name)
 585
 586 #define early_per_cpu(_name, _cpu) per_cpu(_name, _cpu)
 587 #define early_per_cpu_ptr(_name) NULL
 588 /* no early_per_cpu_map() */
 589
 590 #endif  /* !CONFIG_SMP */
 591
 592 #endif /* _ASM_X86_PERCPU_H */