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 arch_raw_cpu_ptr(ptr)                           \
  56 ({                                                      \
  57         unsigned long tcp_ptr__;                        \
  58         asm volatile("add " __percpu_arg(1) ", %0"      \
  59                      : "=r" (tcp_ptr__)                 \
  60                      : "m" (this_cpu_off), "0" (ptr));  \
  61         (typeof(*(ptr)) __kernel __force *)tcp_ptr__;   \
  62 })
  63 #else
  64 #define __percpu_prefix         ""
  65 #endif
  66
  67 #define __percpu_arg(x)         __percpu_prefix "%" #x
  68
  69 /*
  70  * Initialized pointers to per-cpu variables needed for the boot
  71  * processor need to use these macros to get the proper address
  72  * offset from __per_cpu_load on SMP.
  73  *
  74  * There also must be an entry in vmlinux_64.lds.S
  75  */
  76 #define DECLARE_INIT_PER_CPU(var) \
  77        extern typeof(var) init_per_cpu_var(var)
  78
  79 #ifdef CONFIG_X86_64_SMP
  80 #define init_per_cpu_var(var)  init_per_cpu__##var
  81 #else
  82 #define init_per_cpu_var(var)  var
  83 #endif
  84
  85 /* For arch-specific code, we can use direct single-insn ops (they
  86  * don't give an lvalue though). */
  87 extern void __bad_percpu_size(void);
  88
  89 #define percpu_to_op(op, var, val)                      \
  90 do {                                                    \
  91         typedef typeof(var) pto_T__;                    \
  92         if (0) {                                        \
  93                 pto_T__ pto_tmp__;                      \
  94                 pto_tmp__ = (val);                      \
  95                 (void)pto_tmp__;                        \
  96         }                                               \
  97         switch (sizeof(var)) {                          \
  98         case 1:                                         \
  99                 asm(op "b %1,"__percpu_arg(0)           \
 100                     : "+m" (var)                        \
 101                     : "qi" ((pto_T__)(val)));           \
 102                 break;                                  \
 103         case 2:                                         \
 104                 asm(op "w %1,"__percpu_arg(0)           \
 105                     : "+m" (var)                        \
 106                     : "ri" ((pto_T__)(val)));           \
 107                 break;                                  \
 108         case 4:                                         \
 109                 asm(op "l %1,"__percpu_arg(0)           \
 110                     : "+m" (var)                        \
 111                     : "ri" ((pto_T__)(val)));           \
 112                 break;                                  \
 113         case 8:                                         \
 114                 asm(op "q %1,"__percpu_arg(0)           \
 115                     : "+m" (var)                        \
 116                     : "re" ((pto_T__)(val)));           \
 117                 break;                                  \
 118         default: __bad_percpu_size();                   \
 119         }                                               \
 120 } while (0)
 121
 122 /*
 123  * Generate a percpu add to memory instruction and optimize code
 124  * if one is added or subtracted.
 125  */
 126 #define percpu_add_op(var, val)                                         \
 127 do {                                                                    \
 128         typedef typeof(var) pao_T__;                                    \
 129         const int pao_ID__ = (__builtin_constant_p(val) &&              \
 130                               ((val) == 1 || (val) == -1)) ?            \
 131                                 (int)(val) : 0;                         \
 132         if (0) {                                                        \
 133                 pao_T__ pao_tmp__;                                      \
 134                 pao_tmp__ = (val);                                      \
 135                 (void)pao_tmp__;                                        \
 136         }                                                               \
 137         switch (sizeof(var)) {                                          \
 138         case 1:                                                         \
 139                 if (pao_ID__ == 1)                                      \
 140                         asm("incb "__percpu_arg(0) : "+m" (var));       \
 141                 else if (pao_ID__ == -1)                                \
 142                         asm("decb "__percpu_arg(0) : "+m" (var));       \
 143                 else                                                    \
 144                         asm("addb %1, "__percpu_arg(0)                  \
 145                             : "+m" (var)                                \
 146                             : "qi" ((pao_T__)(val)));                   \
 147                 break;                                                  \
 148         case 2:                                                         \
 149                 if (pao_ID__ == 1)                                      \
 150                         asm("incw "__percpu_arg(0) : "+m" (var));       \
 151                 else if (pao_ID__ == -1)                                \
 152                         asm("decw "__percpu_arg(0) : "+m" (var));       \
 153                 else                                                    \
 154                         asm("addw %1, "__percpu_arg(0)                  \
 155                             : "+m" (var)                                \
 156                             : "ri" ((pao_T__)(val)));                   \
 157                 break;                                                  \
 158         case 4:                                                         \
 159                 if (pao_ID__ == 1)                                      \
 160                         asm("incl "__percpu_arg(0) : "+m" (var));       \
 161                 else if (pao_ID__ == -1)                                \
 162                         asm("decl "__percpu_arg(0) : "+m" (var));       \
 163                 else                                                    \
 164                         asm("addl %1, "__percpu_arg(0)                  \
 165                             : "+m" (var)                                \
 166                             : "ri" ((pao_T__)(val)));                   \
 167                 break;                                                  \
 168         case 8:                                                         \
 169                 if (pao_ID__ == 1)                                      \
 170                         asm("incq "__percpu_arg(0) : "+m" (var));       \
 171                 else if (pao_ID__ == -1)                                \
 172                         asm("decq "__percpu_arg(0) : "+m" (var));       \
 173                 else                                                    \
 174                         asm("addq %1, "__percpu_arg(0)                  \
 175                             : "+m" (var)                                \
 176                             : "re" ((pao_T__)(val)));                   \
 177                 break;                                                  \
 178         default: __bad_percpu_size();                                   \
 179         }                                                               \
 180 } while (0)
 181
 182 #define percpu_from_op(op, var)                         \
 183 ({                                                      \
 184         typeof(var) pfo_ret__;                          \
 185         switch (sizeof(var)) {                          \
 186         case 1:                                         \
 187                 asm(op "b "__percpu_arg(1)",%0"         \
 188                     : "=q" (pfo_ret__)                  \
 189                     : "m" (var));                       \
 190                 break;                                  \
 191         case 2:                                         \
 192                 asm(op "w "__percpu_arg(1)",%0"         \
 193                     : "=r" (pfo_ret__)                  \
 194                     : "m" (var));                       \
 195                 break;                                  \
 196         case 4:                                         \
 197                 asm(op "l "__percpu_arg(1)",%0"         \
 198                     : "=r" (pfo_ret__)                  \
 199                     : "m" (var));                       \
 200                 break;                                  \
 201         case 8:                                         \
 202                 asm(op "q "__percpu_arg(1)",%0"         \
 203                     : "=r" (pfo_ret__)                  \
 204                     : "m" (var));                       \
 205                 break;                                  \
 206         default: __bad_percpu_size();                   \
 207         }                                               \
 208         pfo_ret__;                                      \
 209 })
 210
 211 #define percpu_stable_op(op, var)                       \
 212 ({                                                      \
 213         typeof(var) pfo_ret__;                          \
 214         switch (sizeof(var)) {                          \
 215         case 1:                                         \
 216                 asm(op "b "__percpu_arg(P1)",%0"        \
 217                     : "=q" (pfo_ret__)                  \
 218                     : "p" (&(var)));                    \
 219                 break;                                  \
 220         case 2:                                         \
 221                 asm(op "w "__percpu_arg(P1)",%0"        \
 222                     : "=r" (pfo_ret__)                  \
 223                     : "p" (&(var)));                    \
 224                 break;                                  \
 225         case 4:                                         \
 226                 asm(op "l "__percpu_arg(P1)",%0"        \
 227                     : "=r" (pfo_ret__)                  \
 228                     : "p" (&(var)));                    \
 229                 break;                                  \
 230         case 8:                                         \
 231                 asm(op "q "__percpu_arg(P1)",%0"        \
 232                     : "=r" (pfo_ret__)                  \
 233                     : "p" (&(var)));                    \
 234                 break;                                  \
 235         default: __bad_percpu_size();                   \
 236         }                                               \
 237         pfo_ret__;                                      \
 238 })
 239
 240 #define percpu_unary_op(op, var)                        \
 241 ({                                                      \
 242         switch (sizeof(var)) {                          \
 243         case 1:                                         \
 244                 asm(op "b "__percpu_arg(0)              \
 245                     : "+m" (var));                      \
 246                 break;                                  \
 247         case 2:                                         \
 248                 asm(op "w "__percpu_arg(0)              \
 249                     : "+m" (var));                      \
 250                 break;                                  \
 251         case 4:                                         \
 252                 asm(op "l "__percpu_arg(0)              \
 253                     : "+m" (var));                      \
 254                 break;                                  \
 255         case 8:                                         \
 256                 asm(op "q "__percpu_arg(0)              \
 257                     : "+m" (var));                      \
 258                 break;                                  \
 259         default: __bad_percpu_size();                   \
 260         }                                               \
 261 })
 262
 263 /*
 264  * Add return operation
 265  */
 266 #define percpu_add_return_op(var, val)                                  \
 267 ({                                                                      \
 268         typeof(var) paro_ret__ = val;                                   \
 269         switch (sizeof(var)) {                                          \
 270         case 1:                                                         \
 271                 asm("xaddb %0, "__percpu_arg(1)                         \
 272                             : "+q" (paro_ret__), "+m" (var)             \
 273                             : : "memory");                              \
 274                 break;                                                  \
 275         case 2:                                                         \
 276                 asm("xaddw %0, "__percpu_arg(1)                         \
 277                             : "+r" (paro_ret__), "+m" (var)             \
 278                             : : "memory");                              \
 279                 break;                                                  \
 280         case 4:                                                         \
 281                 asm("xaddl %0, "__percpu_arg(1)                         \
 282                             : "+r" (paro_ret__), "+m" (var)             \
 283                             : : "memory");                              \
 284                 break;                                                  \
 285         case 8:                                                         \
 286                 asm("xaddq %0, "__percpu_arg(1)                         \
 287                             : "+re" (paro_ret__), "+m" (var)            \
 288                             : : "memory");                              \
 289                 break;                                                  \
 290         default: __bad_percpu_size();                                   \
 291         }                                                               \
 292         paro_ret__ += val;                                              \
 293         paro_ret__;                                                     \
 294 })
 295
 296 /*
 297  * xchg is implemented using cmpxchg without a lock prefix. xchg is
 298  * expensive due to the implied lock prefix.  The processor cannot prefetch
 299  * cachelines if xchg is used.
 300  */
 301 #define percpu_xchg_op(var, nval)                                       \
 302 ({                                                                      \
 303         typeof(var) pxo_ret__;                                          \
 304         typeof(var) pxo_new__ = (nval);                                 \
 305         switch (sizeof(var)) {                                          \
 306         case 1:                                                         \
 307                 asm("\n\tmov "__percpu_arg(1)",%%al"                    \
 308                     "\n1:\tcmpxchgb %2, "__percpu_arg(1)                \
 309                     "\n\tjnz 1b"                                        \
 310                             : "=&a" (pxo_ret__), "+m" (var)             \
 311                             : "q" (pxo_new__)                           \
 312                             : "memory");                                \
 313                 break;                                                  \
 314         case 2:                                                         \
 315                 asm("\n\tmov "__percpu_arg(1)",%%ax"                    \
 316                     "\n1:\tcmpxchgw %2, "__percpu_arg(1)                \
 317                     "\n\tjnz 1b"                                        \
 318                             : "=&a" (pxo_ret__), "+m" (var)             \
 319                             : "r" (pxo_new__)                           \
 320                             : "memory");                                \
 321                 break;                                                  \
 322         case 4:                                                         \
 323                 asm("\n\tmov "__percpu_arg(1)",%%eax"                   \
 324                     "\n1:\tcmpxchgl %2, "__percpu_arg(1)                \
 325                     "\n\tjnz 1b"                                        \
 326                             : "=&a" (pxo_ret__), "+m" (var)             \
 327                             : "r" (pxo_new__)                           \
 328                             : "memory");                                \
 329                 break;                                                  \
 330         case 8:                                                         \
 331                 asm("\n\tmov "__percpu_arg(1)",%%rax"                   \
 332                     "\n1:\tcmpxchgq %2, "__percpu_arg(1)                \
 333                     "\n\tjnz 1b"                                        \
 334                             : "=&a" (pxo_ret__), "+m" (var)             \
 335                             : "r" (pxo_new__)                           \
 336                             : "memory");                                \
 337                 break;                                                  \
 338         default: __bad_percpu_size();                                   \
 339         }                                                               \
 340         pxo_ret__;                                                      \
 341 })
 342
 343 /*
 344  * cmpxchg has no such implied lock semantics as a result it is much
 345  * more efficient for cpu local operations.
 346  */
 347 #define percpu_cmpxchg_op(var, oval, nval)                              \
 348 ({                                                                      \
 349         typeof(var) pco_ret__;                                          \
 350         typeof(var) pco_old__ = (oval);                                 \
 351         typeof(var) pco_new__ = (nval);                                 \
 352         switch (sizeof(var)) {                                          \
 353         case 1:                                                         \
 354                 asm("cmpxchgb %2, "__percpu_arg(1)                      \
 355                             : "=a" (pco_ret__), "+m" (var)              \
 356                             : "q" (pco_new__), "0" (pco_old__)          \
 357                             : "memory");                                \
 358                 break;                                                  \
 359         case 2:                                                         \
 360                 asm("cmpxchgw %2, "__percpu_arg(1)                      \
 361                             : "=a" (pco_ret__), "+m" (var)              \
 362                             : "r" (pco_new__), "0" (pco_old__)          \
 363                             : "memory");                                \
 364                 break;                                                  \
 365         case 4:                                                         \
 366                 asm("cmpxchgl %2, "__percpu_arg(1)                      \
 367                             : "=a" (pco_ret__), "+m" (var)              \
 368                             : "r" (pco_new__), "0" (pco_old__)          \
 369                             : "memory");                                \
 370                 break;                                                  \
 371         case 8:                                                         \
 372                 asm("cmpxchgq %2, "__percpu_arg(1)                      \
 373                             : "=a" (pco_ret__), "+m" (var)              \
 374                             : "r" (pco_new__), "0" (pco_old__)          \
 375                             : "memory");                                \
 376                 break;                                                  \
 377         default: __bad_percpu_size();                                   \
 378         }                                                               \
 379         pco_ret__;                                                      \
 380 })
 381
 382 /*
 383  * this_cpu_read() makes gcc load the percpu variable every time it is
 384  * accessed while this_cpu_read_stable() allows the value to be cached.
 385  * this_cpu_read_stable() is more efficient and can be used if its value
 386  * is guaranteed to be valid across cpus.  The current users include
 387  * get_current() and get_thread_info() both of which are actually
 388  * per-thread variables implemented as per-cpu variables and thus
 389  * stable for the duration of the respective task.
 390  */
 391 #define this_cpu_read_stable(var)       percpu_stable_op("mov", var)
 392
 393 #define raw_cpu_read_1(pcp)             percpu_from_op("mov", pcp)
 394 #define raw_cpu_read_2(pcp)             percpu_from_op("mov", pcp)
 395 #define raw_cpu_read_4(pcp)             percpu_from_op("mov", pcp)
 396
 397 #define raw_cpu_write_1(pcp, val)       percpu_to_op("mov", (pcp), val)
 398 #define raw_cpu_write_2(pcp, val)       percpu_to_op("mov", (pcp), val)
 399 #define raw_cpu_write_4(pcp, val)       percpu_to_op("mov", (pcp), val)
 400 #define raw_cpu_add_1(pcp, val)         percpu_add_op((pcp), val)
 401 #define raw_cpu_add_2(pcp, val)         percpu_add_op((pcp), val)
 402 #define raw_cpu_add_4(pcp, val)         percpu_add_op((pcp), val)
 403 #define raw_cpu_and_1(pcp, val)         percpu_to_op("and", (pcp), val)
 404 #define raw_cpu_and_2(pcp, val)         percpu_to_op("and", (pcp), val)
 405 #define raw_cpu_and_4(pcp, val)         percpu_to_op("and", (pcp), val)
 406 #define raw_cpu_or_1(pcp, val)          percpu_to_op("or", (pcp), val)
 407 #define raw_cpu_or_2(pcp, val)          percpu_to_op("or", (pcp), val)
 408 #define raw_cpu_or_4(pcp, val)          percpu_to_op("or", (pcp), val)
 409 #define raw_cpu_xchg_1(pcp, val)        percpu_xchg_op(pcp, val)
 410 #define raw_cpu_xchg_2(pcp, val)        percpu_xchg_op(pcp, val)
 411 #define raw_cpu_xchg_4(pcp, val)        percpu_xchg_op(pcp, val)
 412
 413 #define this_cpu_read_1(pcp)            percpu_from_op("mov", pcp)
 414 #define this_cpu_read_2(pcp)            percpu_from_op("mov", pcp)
 415 #define this_cpu_read_4(pcp)            percpu_from_op("mov", pcp)
 416 #define this_cpu_write_1(pcp, val)      percpu_to_op("mov", (pcp), val)
 417 #define this_cpu_write_2(pcp, val)      percpu_to_op("mov", (pcp), val)
 418 #define this_cpu_write_4(pcp, val)      percpu_to_op("mov", (pcp), val)
 419 #define this_cpu_add_1(pcp, val)        percpu_add_op((pcp), val)
 420 #define this_cpu_add_2(pcp, val)        percpu_add_op((pcp), val)
 421 #define this_cpu_add_4(pcp, val)        percpu_add_op((pcp), val)
 422 #define this_cpu_and_1(pcp, val)        percpu_to_op("and", (pcp), val)
 423 #define this_cpu_and_2(pcp, val)        percpu_to_op("and", (pcp), val)
 424 #define this_cpu_and_4(pcp, val)        percpu_to_op("and", (pcp), val)
 425 #define this_cpu_or_1(pcp, val)         percpu_to_op("or", (pcp), val)
 426 #define this_cpu_or_2(pcp, val)         percpu_to_op("or", (pcp), val)
 427 #define this_cpu_or_4(pcp, val)         percpu_to_op("or", (pcp), val)
 428 #define this_cpu_xchg_1(pcp, nval)      percpu_xchg_op(pcp, nval)
 429 #define this_cpu_xchg_2(pcp, nval)      percpu_xchg_op(pcp, nval)
 430 #define this_cpu_xchg_4(pcp, nval)      percpu_xchg_op(pcp, nval)
 431
 432 #define raw_cpu_add_return_1(pcp, val)          percpu_add_return_op(pcp, val)
 433 #define raw_cpu_add_return_2(pcp, val)          percpu_add_return_op(pcp, val)
 434 #define raw_cpu_add_return_4(pcp, val)          percpu_add_return_op(pcp, val)
 435 #define raw_cpu_cmpxchg_1(pcp, oval, nval)      percpu_cmpxchg_op(pcp, oval, nval)
 436 #define raw_cpu_cmpxchg_2(pcp, oval, nval)      percpu_cmpxchg_op(pcp, oval, nval)
 437 #define raw_cpu_cmpxchg_4(pcp, oval, nval)      percpu_cmpxchg_op(pcp, oval, nval)
 438
 439 #define this_cpu_add_return_1(pcp, val)         percpu_add_return_op(pcp, val)
 440 #define this_cpu_add_return_2(pcp, val)         percpu_add_return_op(pcp, val)
 441 #define this_cpu_add_return_4(pcp, val)         percpu_add_return_op(pcp, val)
 442 #define this_cpu_cmpxchg_1(pcp, oval, nval)     percpu_cmpxchg_op(pcp, oval, nval)
 443 #define this_cpu_cmpxchg_2(pcp, oval, nval)     percpu_cmpxchg_op(pcp, oval, nval)
 444 #define this_cpu_cmpxchg_4(pcp, oval, nval)     percpu_cmpxchg_op(pcp, oval, nval)
 445
 446 #ifdef CONFIG_X86_CMPXCHG64
 447 #define percpu_cmpxchg8b_double(pcp1, pcp2, o1, o2, n1, n2)             \
 448 ({                                                                      \
 449         bool __ret;                                                     \
 450         typeof(pcp1) __o1 = (o1), __n1 = (n1);                          \
 451         typeof(pcp2) __o2 = (o2), __n2 = (n2);                          \
 452         asm volatile("cmpxchg8b "__percpu_arg(1)"\n\tsetz %0\n\t"       \
 453                     : "=a" (__ret), "+m" (pcp1), "+m" (pcp2), "+d" (__o2) \
 454                     :  "b" (__n1), "c" (__n2), "a" (__o1));             \
 455         __ret;                                                          \
 456 })
 457
 458 #define raw_cpu_cmpxchg_double_4        percpu_cmpxchg8b_double
 459 #define this_cpu_cmpxchg_double_4       percpu_cmpxchg8b_double
 460 #endif /* CONFIG_X86_CMPXCHG64 */
 461
 462 /*
 463  * Per cpu atomic 64 bit operations are only available under 64 bit.
 464  * 32 bit must fall back to generic operations.
 465  */
 466 #ifdef CONFIG_X86_64
 467 #define raw_cpu_read_8(pcp)                     percpu_from_op("mov", pcp)
 468 #define raw_cpu_write_8(pcp, val)               percpu_to_op("mov", (pcp), val)
 469 #define raw_cpu_add_8(pcp, val)                 percpu_add_op((pcp), val)
 470 #define raw_cpu_and_8(pcp, val)                 percpu_to_op("and", (pcp), val)
 471 #define raw_cpu_or_8(pcp, val)                  percpu_to_op("or", (pcp), val)
 472 #define raw_cpu_add_return_8(pcp, val)          percpu_add_return_op(pcp, val)
 473 #define raw_cpu_xchg_8(pcp, nval)               percpu_xchg_op(pcp, nval)
 474 #define raw_cpu_cmpxchg_8(pcp, oval, nval)      percpu_cmpxchg_op(pcp, oval, nval)
 475
 476 #define this_cpu_read_8(pcp)                    percpu_from_op("mov", pcp)
 477 #define this_cpu_write_8(pcp, val)              percpu_to_op("mov", (pcp), val)
 478 #define this_cpu_add_8(pcp, val)                percpu_add_op((pcp), val)
 479 #define this_cpu_and_8(pcp, val)                percpu_to_op("and", (pcp), val)
 480 #define this_cpu_or_8(pcp, val)                 percpu_to_op("or", (pcp), val)
 481 #define this_cpu_add_return_8(pcp, val)         percpu_add_return_op(pcp, val)
 482 #define this_cpu_xchg_8(pcp, nval)              percpu_xchg_op(pcp, nval)
 483 #define this_cpu_cmpxchg_8(pcp, oval, nval)     percpu_cmpxchg_op(pcp, oval, nval)
 484
 485 /*
 486  * Pretty complex macro to generate cmpxchg16 instruction.  The instruction
 487  * is not supported on early AMD64 processors so we must be able to emulate
 488  * it in software.  The address used in the cmpxchg16 instruction must be
 489  * aligned to a 16 byte boundary.
 490  */
 491 #define percpu_cmpxchg16b_double(pcp1, pcp2, o1, o2, n1, n2)            \
 492 ({                                                                      \
 493         bool __ret;                                                     \
 494         typeof(pcp1) __o1 = (o1), __n1 = (n1);                          \
 495         typeof(pcp2) __o2 = (o2), __n2 = (n2);                          \
 496         alternative_io("leaq %P1,%%rsi\n\tcall this_cpu_cmpxchg16b_emu\n\t", \
 497                        "cmpxchg16b " __percpu_arg(1) "\n\tsetz %0\n\t", \
 498                        X86_FEATURE_CX16,                                \
 499                        ASM_OUTPUT2("=a" (__ret), "+m" (pcp1),           \
 500                                    "+m" (pcp2), "+d" (__o2)),           \
 501                        "b" (__n1), "c" (__n2), "a" (__o1) : "rsi");     \
 502         __ret;                                                          \
 503 })
 504
 505 #define raw_cpu_cmpxchg_double_8        percpu_cmpxchg16b_double
 506 #define this_cpu_cmpxchg_double_8       percpu_cmpxchg16b_double
 507
 508 #endif
 509
 510 /* This is not atomic against other CPUs -- CPU preemption needs to be off */
 511 #define x86_test_and_clear_bit_percpu(bit, var)                         \
 512 ({                                                                      \
 513         bool old__;                                                     \
 514         asm volatile("btr %2,"__percpu_arg(1)"\n\t"                     \
 515                      CC_SET(c)                                          \
 516                      : CC_OUT(c) (old__), "+m" (var)                    \
 517                      : "dIr" (bit));                                    \
 518         old__;                                                          \
 519 })
 520
 521 static __always_inline bool x86_this_cpu_constant_test_bit(unsigned int nr,
 522                         const unsigned long __percpu *addr)
 523 {
 524         unsigned long __percpu *a = (unsigned long *)addr + nr / BITS_PER_LONG;
 525
 526 #ifdef CONFIG_X86_64
 527         return ((1UL << (nr % BITS_PER_LONG)) & raw_cpu_read_8(*a)) != 0;
 528 #else
 529         return ((1UL << (nr % BITS_PER_LONG)) & raw_cpu_read_4(*a)) != 0;
 530 #endif
 531 }
 532
 533 static inline bool x86_this_cpu_variable_test_bit(int nr,
 534                         const unsigned long __percpu *addr)
 535 {
 536         bool oldbit;
 537
 538         asm volatile("bt "__percpu_arg(2)",%1\n\t"
 539                         CC_SET(c)
 540                         : CC_OUT(c) (oldbit)
 541                         : "m" (*(unsigned long *)addr), "Ir" (nr));
 542
 543         return oldbit;
 544 }
 545
 546 #define x86_this_cpu_test_bit(nr, addr)                 \
 547         (__builtin_constant_p((nr))                     \
 548          ? x86_this_cpu_constant_test_bit((nr), (addr)) \
 549          : x86_this_cpu_variable_test_bit((nr), (addr)))
 550
 551
 552 #include <asm-generic/percpu.h>
 553
 554 /* We can use this directly for local CPU (faster). */
 555 DECLARE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off);
 556
 557 #endif /* !__ASSEMBLY__ */
 558
 559 #ifdef CONFIG_SMP
 560
 561 /*
 562  * Define the "EARLY_PER_CPU" macros.  These are used for some per_cpu
 563  * variables that are initialized and accessed before there are per_cpu
 564  * areas allocated.
 565  */
 566
 567 #define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)                  \
 568         DEFINE_PER_CPU(_type, _name) = _initvalue;                      \
 569         __typeof__(_type) _name##_early_map[NR_CPUS] __initdata =       \
 570                                 { [0 ... NR_CPUS-1] = _initvalue };     \
 571         __typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
 572
 573 #define DEFINE_EARLY_PER_CPU_READ_MOSTLY(_type, _name, _initvalue)      \
 574         DEFINE_PER_CPU_READ_MOSTLY(_type, _name) = _initvalue;          \
 575         __typeof__(_type) _name##_early_map[NR_CPUS] __initdata =       \
 576                                 { [0 ... NR_CPUS-1] = _initvalue };     \
 577         __typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
 578
 579 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name)                      \
 580         EXPORT_PER_CPU_SYMBOL(_name)
 581
 582 #define DECLARE_EARLY_PER_CPU(_type, _name)                     \
 583         DECLARE_PER_CPU(_type, _name);                          \
 584         extern __typeof__(_type) *_name##_early_ptr;            \
 585         extern __typeof__(_type)  _name##_early_map[]
 586
 587 #define DECLARE_EARLY_PER_CPU_READ_MOSTLY(_type, _name)         \
 588         DECLARE_PER_CPU_READ_MOSTLY(_type, _name);              \
 589         extern __typeof__(_type) *_name##_early_ptr;            \
 590         extern __typeof__(_type)  _name##_early_map[]
 591
 592 #define early_per_cpu_ptr(_name) (_name##_early_ptr)
 593 #define early_per_cpu_map(_name, _idx) (_name##_early_map[_idx])
 594 #define early_per_cpu(_name, _cpu)                              \
 595         *(early_per_cpu_ptr(_name) ?                            \
 596                 &early_per_cpu_ptr(_name)[_cpu] :               \
 597                 &per_cpu(_name, _cpu))
 598
 599 #else   /* !CONFIG_SMP */
 600 #define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)          \
 601         DEFINE_PER_CPU(_type, _name) = _initvalue
 602
 603 #define DEFINE_EARLY_PER_CPU_READ_MOSTLY(_type, _name, _initvalue)      \
 604         DEFINE_PER_CPU_READ_MOSTLY(_type, _name) = _initvalue
 605
 606 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name)                      \
 607         EXPORT_PER_CPU_SYMBOL(_name)
 608
 609 #define DECLARE_EARLY_PER_CPU(_type, _name)                     \
 610         DECLARE_PER_CPU(_type, _name)
 611
 612 #define DECLARE_EARLY_PER_CPU_READ_MOSTLY(_type, _name)         \
 613         DECLARE_PER_CPU_READ_MOSTLY(_type, _name)
 614
 615 #define early_per_cpu(_name, _cpu) per_cpu(_name, _cpu)
 616 #define early_per_cpu_ptr(_name) NULL
 617 /* no early_per_cpu_map() */
 618
 619 #endif  /* !CONFIG_SMP */
 620
 621 #endif /* _ASM_X86_PERCPU_H */