include/linux/percpu.h

   1 #ifndef __LINUX_PERCPU_H
   2 #define __LINUX_PERCPU_H
   3
   4 #include <linux/preempt.h>
   5 #include <linux/smp.h>
   6 #include <linux/cpumask.h>
   7 #include <linux/pfn.h>
   8 #include <linux/init.h>
   9
  10 #include <asm/percpu.h>
  11
  12 /* enough to cover all DEFINE_PER_CPUs in modules */
  13 #ifdef CONFIG_MODULES
  14 #define PERCPU_MODULE_RESERVE           (8 << 10)
  15 #else
  16 #define PERCPU_MODULE_RESERVE           0
  17 #endif
  18
  19 #ifndef PERCPU_ENOUGH_ROOM
  20 #define PERCPU_ENOUGH_ROOM                                              \
  21         (ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES) +      \
  22          PERCPU_MODULE_RESERVE)
  23 #endif
  24
  25 /*
  26  * Must be an lvalue. Since @var must be a simple identifier,
  27  * we force a syntax error here if it isn't.
  28  */
  29 #define get_cpu_var(var) (*({                           \
  30         preempt_disable();                              \
  31         &__get_cpu_var(var); }))
  32
  33 /*
  34  * The weird & is necessary because sparse considers (void)(var) to be
  35  * a direct dereference of percpu variable (var).
  36  */
  37 #define put_cpu_var(var) do {                           \
  38         (void)&(var);                                   \
  39         preempt_enable();                               \
  40 } while (0)
  41
  42 #define get_cpu_ptr(var) ({                             \
  43         preempt_disable();                              \
  44         this_cpu_ptr(var); })
  45
  46 #define put_cpu_ptr(var) do {                           \
  47         (void)(var);                                    \
  48         preempt_enable();                               \
  49 } while (0)
  50
  51 /* minimum unit size, also is the maximum supported allocation size */
  52 #define PCPU_MIN_UNIT_SIZE              PFN_ALIGN(32 << 10)
  53
  54 /*
  55  * Percpu allocator can serve percpu allocations before slab is
  56  * initialized which allows slab to depend on the percpu allocator.
  57  * The following two parameters decide how much resource to
  58  * preallocate for this.  Keep PERCPU_DYNAMIC_RESERVE equal to or
  59  * larger than PERCPU_DYNAMIC_EARLY_SIZE.
  60  */
  61 #define PERCPU_DYNAMIC_EARLY_SLOTS      128
  62 #define PERCPU_DYNAMIC_EARLY_SIZE       (12 << 10)
  63
  64 /*
  65  * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy
  66  * back on the first chunk for dynamic percpu allocation if arch is
  67  * manually allocating and mapping it for faster access (as a part of
  68  * large page mapping for example).
  69  *
  70  * The following values give between one and two pages of free space
  71  * after typical minimal boot (2-way SMP, single disk and NIC) with
  72  * both defconfig and a distro config on x86_64 and 32.  More
  73  * intelligent way to determine this would be nice.
  74  */
  75 #if BITS_PER_LONG > 32
  76 #define PERCPU_DYNAMIC_RESERVE          (20 << 10)
  77 #else
  78 #define PERCPU_DYNAMIC_RESERVE          (12 << 10)
  79 #endif
  80
  81 extern void *pcpu_base_addr;
  82 extern const unsigned long *pcpu_unit_offsets;
  83
  84 struct pcpu_group_info {
  85         int                     nr_units;       /* aligned # of units */
  86         unsigned long           base_offset;    /* base address offset */
  87         unsigned int            *cpu_map;       /* unit->cpu map, empty
  88                                                  * entries contain NR_CPUS */
  89 };
  90
  91 struct pcpu_alloc_info {
  92         size_t                  static_size;
  93         size_t                  reserved_size;
  94         size_t                  dyn_size;
  95         size_t                  unit_size;
  96         size_t                  atom_size;
  97         size_t                  alloc_size;
  98         size_t                  __ai_size;      /* internal, don't use */
  99         int                     nr_groups;      /* 0 if grouping unnecessary */
 100         struct pcpu_group_info  groups[];
 101 };
 102
 103 enum pcpu_fc {
 104         PCPU_FC_AUTO,
 105         PCPU_FC_EMBED,
 106         PCPU_FC_PAGE,
 107
 108         PCPU_FC_NR,
 109 };
 110 extern const char * const pcpu_fc_names[PCPU_FC_NR];
 111
 112 extern enum pcpu_fc pcpu_chosen_fc;
 113
 114 typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
 115                                      size_t align);
 116 typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
 117 typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
 118 typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
 119
 120 extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
 121                                                              int nr_units);
 122 extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
 123
 124 extern int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
 125                                          void *base_addr);
 126
 127 #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
 128 extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
 129                                 size_t atom_size,
 130                                 pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
 131                                 pcpu_fc_alloc_fn_t alloc_fn,
 132                                 pcpu_fc_free_fn_t free_fn);
 133 #endif
 134
 135 #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
 136 extern int __init pcpu_page_first_chunk(size_t reserved_size,
 137                                 pcpu_fc_alloc_fn_t alloc_fn,
 138                                 pcpu_fc_free_fn_t free_fn,
 139                                 pcpu_fc_populate_pte_fn_t populate_pte_fn);
 140 #endif
 141
 142 /*
 143  * Use this to get to a cpu's version of the per-cpu object
 144  * dynamically allocated. Non-atomic access to the current CPU's
 145  * version should probably be combined with get_cpu()/put_cpu().
 146  */
 147 #ifdef CONFIG_SMP
 148 #define per_cpu_ptr(ptr, cpu)   SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu)))
 149 #else
 150 #define per_cpu_ptr(ptr, cpu)   ({ (void)(cpu); VERIFY_PERCPU_PTR((ptr)); })
 151 #endif
 152
 153 extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
 154 extern bool is_kernel_percpu_address(unsigned long addr);
 155
 156 #if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
 157 extern void __init setup_per_cpu_areas(void);
 158 #endif
 159 extern void __init percpu_init_late(void);
 160
 161 extern void __percpu *__alloc_percpu(size_t size, size_t align);
 162 extern void free_percpu(void __percpu *__pdata);
 163 extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
 164
 165 #define alloc_percpu(type)      \
 166         (typeof(type) __percpu *)__alloc_percpu(sizeof(type), __alignof__(type))
 167
 168 /*
 169  * Branching function to split up a function into a set of functions that
 170  * are called for different scalar sizes of the objects handled.
 171  */
 172
 173 extern void __bad_size_call_parameter(void);
 174
 175 #define __pcpu_size_call_return(stem, variable)                         \
 176 ({      typeof(variable) pscr_ret__;                                    \
 177         __verify_pcpu_ptr(&(variable));                                 \
 178         switch(sizeof(variable)) {                                      \
 179         case 1: pscr_ret__ = stem##1(variable);break;                   \
 180         case 2: pscr_ret__ = stem##2(variable);break;                   \
 181         case 4: pscr_ret__ = stem##4(variable);break;                   \
 182         case 8: pscr_ret__ = stem##8(variable);break;                   \
 183         default:                                                        \
 184                 __bad_size_call_parameter();break;                      \
 185         }                                                               \
 186         pscr_ret__;                                                     \
 187 })
 188
 189 #define __pcpu_size_call_return2(stem, variable, ...)                   \
 190 ({                                                                      \
 191         typeof(variable) pscr2_ret__;                                   \
 192         __verify_pcpu_ptr(&(variable));                                 \
 193         switch(sizeof(variable)) {                                      \
 194         case 1: pscr2_ret__ = stem##1(variable, __VA_ARGS__); break;    \
 195         case 2: pscr2_ret__ = stem##2(variable, __VA_ARGS__); break;    \
 196         case 4: pscr2_ret__ = stem##4(variable, __VA_ARGS__); break;    \
 197         case 8: pscr2_ret__ = stem##8(variable, __VA_ARGS__); break;    \
 198         default:                                                        \
 199                 __bad_size_call_parameter(); break;                     \
 200         }                                                               \
 201         pscr2_ret__;                                                    \
 202 })
 203
 204 /*
 205  * Special handling for cmpxchg_double.  cmpxchg_double is passed two
 206  * percpu variables.  The first has to be aligned to a double word
 207  * boundary and the second has to follow directly thereafter.
 208  * We enforce this on all architectures even if they don't support
 209  * a double cmpxchg instruction, since it's a cheap requirement, and it
 210  * avoids breaking the requirement for architectures with the instruction.
 211  */
 212 #define __pcpu_double_call_return_bool(stem, pcp1, pcp2, ...)           \
 213 ({                                                                      \
 214         bool pdcrb_ret__;                                               \
 215         __verify_pcpu_ptr(&pcp1);                                       \
 216         BUILD_BUG_ON(sizeof(pcp1) != sizeof(pcp2));                     \
 217         VM_BUG_ON((unsigned long)(&pcp1) % (2 * sizeof(pcp1)));         \
 218         VM_BUG_ON((unsigned long)(&pcp2) !=                             \
 219                   (unsigned long)(&pcp1) + sizeof(pcp1));               \
 220         switch(sizeof(pcp1)) {                                          \
 221         case 1: pdcrb_ret__ = stem##1(pcp1, pcp2, __VA_ARGS__); break;  \
 222         case 2: pdcrb_ret__ = stem##2(pcp1, pcp2, __VA_ARGS__); break;  \
 223         case 4: pdcrb_ret__ = stem##4(pcp1, pcp2, __VA_ARGS__); break;  \
 224         case 8: pdcrb_ret__ = stem##8(pcp1, pcp2, __VA_ARGS__); break;  \
 225         default:                                                        \
 226                 __bad_size_call_parameter(); break;                     \
 227         }                                                               \
 228         pdcrb_ret__;                                                    \
 229 })
 230
 231 #define __pcpu_size_call(stem, variable, ...)                           \
 232 do {                                                                    \
 233         __verify_pcpu_ptr(&(variable));                                 \
 234         switch(sizeof(variable)) {                                      \
 235                 case 1: stem##1(variable, __VA_ARGS__);break;           \
 236                 case 2: stem##2(variable, __VA_ARGS__);break;           \
 237                 case 4: stem##4(variable, __VA_ARGS__);break;           \
 238                 case 8: stem##8(variable, __VA_ARGS__);break;           \
 239                 default:                                                \
 240                         __bad_size_call_parameter();break;              \
 241         }                                                               \
 242 } while (0)
 243
 244 /*
 245  * Optimized manipulation for memory allocated through the per cpu
 246  * allocator or for addresses of per cpu variables.
 247  *
 248  * These operation guarantee exclusivity of access for other operations
 249  * on the *same* processor. The assumption is that per cpu data is only
 250  * accessed by a single processor instance (the current one).
 251  *
 252  * The first group is used for accesses that must be done in a
 253  * preemption safe way since we know that the context is not preempt
 254  * safe. Interrupts may occur. If the interrupt modifies the variable
 255  * too then RMW actions will not be reliable.
 256  *
 257  * The arch code can provide optimized functions in two ways:
 258  *
 259  * 1. Override the function completely. F.e. define this_cpu_add().
 260  *    The arch must then ensure that the various scalar format passed
 261  *    are handled correctly.
 262  *
 263  * 2. Provide functions for certain scalar sizes. F.e. provide
 264  *    this_cpu_add_2() to provide per cpu atomic operations for 2 byte
 265  *    sized RMW actions. If arch code does not provide operations for
 266  *    a scalar size then the fallback in the generic code will be
 267  *    used.
 268  */
 269
 270 #define _this_cpu_generic_read(pcp)                                     \
 271 ({      typeof(pcp) ret__;                                              \
 272         preempt_disable();                                              \
 273         ret__ = *this_cpu_ptr(&(pcp));                                  \
 274         preempt_enable();                                               \
 275         ret__;                                                          \
 276 })
 277
 278 #ifndef this_cpu_read
 279 # ifndef this_cpu_read_1
 280 #  define this_cpu_read_1(pcp)  _this_cpu_generic_read(pcp)
 281 # endif
 282 # ifndef this_cpu_read_2
 283 #  define this_cpu_read_2(pcp)  _this_cpu_generic_read(pcp)
 284 # endif
 285 # ifndef this_cpu_read_4
 286 #  define this_cpu_read_4(pcp)  _this_cpu_generic_read(pcp)
 287 # endif
 288 # ifndef this_cpu_read_8
 289 #  define this_cpu_read_8(pcp)  _this_cpu_generic_read(pcp)
 290 # endif
 291 # define this_cpu_read(pcp)     __pcpu_size_call_return(this_cpu_read_, (pcp))
 292 #endif
 293
 294 #define _this_cpu_generic_to_op(pcp, val, op)                           \
 295 do {                                                                    \
 296         unsigned long flags;                                            \
 297         raw_local_irq_save(flags);                                      \
 298         *__this_cpu_ptr(&(pcp)) op val;                                 \
 299         raw_local_irq_restore(flags);                                   \
 300 } while (0)
 301
 302 #ifndef this_cpu_write
 303 # ifndef this_cpu_write_1
 304 #  define this_cpu_write_1(pcp, val)    _this_cpu_generic_to_op((pcp), (val), =)
 305 # endif
 306 # ifndef this_cpu_write_2
 307 #  define this_cpu_write_2(pcp, val)    _this_cpu_generic_to_op((pcp), (val), =)
 308 # endif
 309 # ifndef this_cpu_write_4
 310 #  define this_cpu_write_4(pcp, val)    _this_cpu_generic_to_op((pcp), (val), =)
 311 # endif
 312 # ifndef this_cpu_write_8
 313 #  define this_cpu_write_8(pcp, val)    _this_cpu_generic_to_op((pcp), (val), =)
 314 # endif
 315 # define this_cpu_write(pcp, val)       __pcpu_size_call(this_cpu_write_, (pcp), (val))
 316 #endif
 317
 318 #ifndef this_cpu_add
 319 # ifndef this_cpu_add_1
 320 #  define this_cpu_add_1(pcp, val)      _this_cpu_generic_to_op((pcp), (val), +=)
 321 # endif
 322 # ifndef this_cpu_add_2
 323 #  define this_cpu_add_2(pcp, val)      _this_cpu_generic_to_op((pcp), (val), +=)
 324 # endif
 325 # ifndef this_cpu_add_4
 326 #  define this_cpu_add_4(pcp, val)      _this_cpu_generic_to_op((pcp), (val), +=)
 327 # endif
 328 # ifndef this_cpu_add_8
 329 #  define this_cpu_add_8(pcp, val)      _this_cpu_generic_to_op((pcp), (val), +=)
 330 # endif
 331 # define this_cpu_add(pcp, val)         __pcpu_size_call(this_cpu_add_, (pcp), (val))
 332 #endif
 333
 334 #ifndef this_cpu_sub
 335 # define this_cpu_sub(pcp, val)         this_cpu_add((pcp), -(val))
 336 #endif
 337
 338 #ifndef this_cpu_inc
 339 # define this_cpu_inc(pcp)              this_cpu_add((pcp), 1)
 340 #endif
 341
 342 #ifndef this_cpu_dec
 343 # define this_cpu_dec(pcp)              this_cpu_sub((pcp), 1)
 344 #endif
 345
 346 #ifndef this_cpu_and
 347 # ifndef this_cpu_and_1
 348 #  define this_cpu_and_1(pcp, val)      _this_cpu_generic_to_op((pcp), (val), &=)
 349 # endif
 350 # ifndef this_cpu_and_2
 351 #  define this_cpu_and_2(pcp, val)      _this_cpu_generic_to_op((pcp), (val), &=)
 352 # endif
 353 # ifndef this_cpu_and_4
 354 #  define this_cpu_and_4(pcp, val)      _this_cpu_generic_to_op((pcp), (val), &=)
 355 # endif
 356 # ifndef this_cpu_and_8
 357 #  define this_cpu_and_8(pcp, val)      _this_cpu_generic_to_op((pcp), (val), &=)
 358 # endif
 359 # define this_cpu_and(pcp, val)         __pcpu_size_call(this_cpu_and_, (pcp), (val))
 360 #endif
 361
 362 #ifndef this_cpu_or
 363 # ifndef this_cpu_or_1
 364 #  define this_cpu_or_1(pcp, val)       _this_cpu_generic_to_op((pcp), (val), |=)
 365 # endif
 366 # ifndef this_cpu_or_2
 367 #  define this_cpu_or_2(pcp, val)       _this_cpu_generic_to_op((pcp), (val), |=)
 368 # endif
 369 # ifndef this_cpu_or_4
 370 #  define this_cpu_or_4(pcp, val)       _this_cpu_generic_to_op((pcp), (val), |=)
 371 # endif
 372 # ifndef this_cpu_or_8
 373 #  define this_cpu_or_8(pcp, val)       _this_cpu_generic_to_op((pcp), (val), |=)
 374 # endif
 375 # define this_cpu_or(pcp, val)          __pcpu_size_call(this_cpu_or_, (pcp), (val))
 376 #endif
 377
 378 #ifndef this_cpu_xor
 379 # ifndef this_cpu_xor_1
 380 #  define this_cpu_xor_1(pcp, val)      _this_cpu_generic_to_op((pcp), (val), ^=)
 381 # endif
 382 # ifndef this_cpu_xor_2
 383 #  define this_cpu_xor_2(pcp, val)      _this_cpu_generic_to_op((pcp), (val), ^=)
 384 # endif
 385 # ifndef this_cpu_xor_4
 386 #  define this_cpu_xor_4(pcp, val)      _this_cpu_generic_to_op((pcp), (val), ^=)
 387 # endif
 388 # ifndef this_cpu_xor_8
 389 #  define this_cpu_xor_8(pcp, val)      _this_cpu_generic_to_op((pcp), (val), ^=)
 390 # endif
 391 # define this_cpu_xor(pcp, val)         __pcpu_size_call(this_cpu_or_, (pcp), (val))
 392 #endif
 393
 394 #define _this_cpu_generic_add_return(pcp, val)                          \
 395 ({                                                                      \
 396         typeof(pcp) ret__;                                              \
 397         unsigned long flags;                                            \
 398         raw_local_irq_save(flags);                                      \
 399         __this_cpu_add(pcp, val);                                       \
 400         ret__ = __this_cpu_read(pcp);                                   \
 401         raw_local_irq_restore(flags);                                   \
 402         ret__;                                                          \
 403 })
 404
 405 #ifndef this_cpu_add_return
 406 # ifndef this_cpu_add_return_1
 407 #  define this_cpu_add_return_1(pcp, val)       _this_cpu_generic_add_return(pcp, val)
 408 # endif
 409 # ifndef this_cpu_add_return_2
 410 #  define this_cpu_add_return_2(pcp, val)       _this_cpu_generic_add_return(pcp, val)
 411 # endif
 412 # ifndef this_cpu_add_return_4
 413 #  define this_cpu_add_return_4(pcp, val)       _this_cpu_generic_add_return(pcp, val)
 414 # endif
 415 # ifndef this_cpu_add_return_8
 416 #  define this_cpu_add_return_8(pcp, val)       _this_cpu_generic_add_return(pcp, val)
 417 # endif
 418 # define this_cpu_add_return(pcp, val)  __pcpu_size_call_return2(this_cpu_add_return_, pcp, val)
 419 #endif
 420
 421 #define this_cpu_sub_return(pcp, val)   this_cpu_add_return(pcp, -(val))
 422 #define this_cpu_inc_return(pcp)        this_cpu_add_return(pcp, 1)
 423 #define this_cpu_dec_return(pcp)        this_cpu_add_return(pcp, -1)
 424
 425 #define _this_cpu_generic_xchg(pcp, nval)                               \
 426 ({      typeof(pcp) ret__;                                              \
 427         unsigned long flags;                                            \
 428         raw_local_irq_save(flags);                                      \
 429         ret__ = __this_cpu_read(pcp);                                   \
 430         __this_cpu_write(pcp, nval);                                    \
 431         raw_local_irq_restore(flags);                                   \
 432         ret__;                                                          \
 433 })
 434
 435 #ifndef this_cpu_xchg
 436 # ifndef this_cpu_xchg_1
 437 #  define this_cpu_xchg_1(pcp, nval)    _this_cpu_generic_xchg(pcp, nval)
 438 # endif
 439 # ifndef this_cpu_xchg_2
 440 #  define this_cpu_xchg_2(pcp, nval)    _this_cpu_generic_xchg(pcp, nval)
 441 # endif
 442 # ifndef this_cpu_xchg_4
 443 #  define this_cpu_xchg_4(pcp, nval)    _this_cpu_generic_xchg(pcp, nval)
 444 # endif
 445 # ifndef this_cpu_xchg_8
 446 #  define this_cpu_xchg_8(pcp, nval)    _this_cpu_generic_xchg(pcp, nval)
 447 # endif
 448 # define this_cpu_xchg(pcp, nval)       \
 449         __pcpu_size_call_return2(this_cpu_xchg_, (pcp), nval)
 450 #endif
 451
 452 #define _this_cpu_generic_cmpxchg(pcp, oval, nval)                      \
 453 ({                                                                      \
 454         typeof(pcp) ret__;                                              \
 455         unsigned long flags;                                            \
 456         raw_local_irq_save(flags);                                      \
 457         ret__ = __this_cpu_read(pcp);                                   \
 458         if (ret__ == (oval))                                            \
 459                 __this_cpu_write(pcp, nval);                            \
 460         raw_local_irq_restore(flags);                                   \
 461         ret__;                                                          \
 462 })
 463
 464 #ifndef this_cpu_cmpxchg
 465 # ifndef this_cpu_cmpxchg_1
 466 #  define this_cpu_cmpxchg_1(pcp, oval, nval)   _this_cpu_generic_cmpxchg(pcp, oval, nval)
 467 # endif
 468 # ifndef this_cpu_cmpxchg_2
 469 #  define this_cpu_cmpxchg_2(pcp, oval, nval)   _this_cpu_generic_cmpxchg(pcp, oval, nval)
 470 # endif
 471 # ifndef this_cpu_cmpxchg_4
 472 #  define this_cpu_cmpxchg_4(pcp, oval, nval)   _this_cpu_generic_cmpxchg(pcp, oval, nval)
 473 # endif
 474 # ifndef this_cpu_cmpxchg_8
 475 #  define this_cpu_cmpxchg_8(pcp, oval, nval)   _this_cpu_generic_cmpxchg(pcp, oval, nval)
 476 # endif
 477 # define this_cpu_cmpxchg(pcp, oval, nval)      \
 478         __pcpu_size_call_return2(this_cpu_cmpxchg_, pcp, oval, nval)
 479 #endif
 480
 481 /*
 482  * cmpxchg_double replaces two adjacent scalars at once.  The first
 483  * two parameters are per cpu variables which have to be of the same
 484  * size.  A truth value is returned to indicate success or failure
 485  * (since a double register result is difficult to handle).  There is
 486  * very limited hardware support for these operations, so only certain
 487  * sizes may work.
 488  */
 489 #define _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)        \
 490 ({                                                                      \
 491         int ret__;                                                      \
 492         unsigned long flags;                                            \
 493         raw_local_irq_save(flags);                                      \
 494         ret__ = __this_cpu_generic_cmpxchg_double(pcp1, pcp2,           \
 495                         oval1, oval2, nval1, nval2);                    \
 496         raw_local_irq_restore(flags);                                   \
 497         ret__;                                                          \
 498 })
 499
 500 #ifndef this_cpu_cmpxchg_double
 501 # ifndef this_cpu_cmpxchg_double_1
 502 #  define this_cpu_cmpxchg_double_1(pcp1, pcp2, oval1, oval2, nval1, nval2)     \
 503         _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 504 # endif
 505 # ifndef this_cpu_cmpxchg_double_2
 506 #  define this_cpu_cmpxchg_double_2(pcp1, pcp2, oval1, oval2, nval1, nval2)     \
 507         _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 508 # endif
 509 # ifndef this_cpu_cmpxchg_double_4
 510 #  define this_cpu_cmpxchg_double_4(pcp1, pcp2, oval1, oval2, nval1, nval2)     \
 511         _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 512 # endif
 513 # ifndef this_cpu_cmpxchg_double_8
 514 #  define this_cpu_cmpxchg_double_8(pcp1, pcp2, oval1, oval2, nval1, nval2)     \
 515         _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 516 # endif
 517 # define this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)        \
 518         __pcpu_double_call_return_bool(this_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
 519 #endif
 520
 521 /*
 522  * Generic percpu operations for context that are safe from preemption/interrupts.
 523  * Either we do not care about races or the caller has the
 524  * responsibility of handling preemption/interrupt issues. Arch code can still
 525  * override these instructions since the arch per cpu code may be more
 526  * efficient and may actually get race freeness for free (that is the
 527  * case for x86 for example).
 528  *
 529  * If there is no other protection through preempt disable and/or
 530  * disabling interupts then one of these RMW operations can show unexpected
 531  * behavior because the execution thread was rescheduled on another processor
 532  * or an interrupt occurred and the same percpu variable was modified from
 533  * the interrupt context.
 534  */
 535 #ifndef __this_cpu_read
 536 # ifndef __this_cpu_read_1
 537 #  define __this_cpu_read_1(pcp)        (*__this_cpu_ptr(&(pcp)))
 538 # endif
 539 # ifndef __this_cpu_read_2
 540 #  define __this_cpu_read_2(pcp)        (*__this_cpu_ptr(&(pcp)))
 541 # endif
 542 # ifndef __this_cpu_read_4
 543 #  define __this_cpu_read_4(pcp)        (*__this_cpu_ptr(&(pcp)))
 544 # endif
 545 # ifndef __this_cpu_read_8
 546 #  define __this_cpu_read_8(pcp)        (*__this_cpu_ptr(&(pcp)))
 547 # endif
 548 # define __this_cpu_read(pcp)   __pcpu_size_call_return(__this_cpu_read_, (pcp))
 549 #endif
 550
 551 #define __this_cpu_generic_to_op(pcp, val, op)                          \
 552 do {                                                                    \
 553         *__this_cpu_ptr(&(pcp)) op val;                                 \
 554 } while (0)
 555
 556 #ifndef __this_cpu_write
 557 # ifndef __this_cpu_write_1
 558 #  define __this_cpu_write_1(pcp, val)  __this_cpu_generic_to_op((pcp), (val), =)
 559 # endif
 560 # ifndef __this_cpu_write_2
 561 #  define __this_cpu_write_2(pcp, val)  __this_cpu_generic_to_op((pcp), (val), =)
 562 # endif
 563 # ifndef __this_cpu_write_4
 564 #  define __this_cpu_write_4(pcp, val)  __this_cpu_generic_to_op((pcp), (val), =)
 565 # endif
 566 # ifndef __this_cpu_write_8
 567 #  define __this_cpu_write_8(pcp, val)  __this_cpu_generic_to_op((pcp), (val), =)
 568 # endif
 569 # define __this_cpu_write(pcp, val)     __pcpu_size_call(__this_cpu_write_, (pcp), (val))
 570 #endif
 571
 572 #ifndef __this_cpu_add
 573 # ifndef __this_cpu_add_1
 574 #  define __this_cpu_add_1(pcp, val)    __this_cpu_generic_to_op((pcp), (val), +=)
 575 # endif
 576 # ifndef __this_cpu_add_2
 577 #  define __this_cpu_add_2(pcp, val)    __this_cpu_generic_to_op((pcp), (val), +=)
 578 # endif
 579 # ifndef __this_cpu_add_4
 580 #  define __this_cpu_add_4(pcp, val)    __this_cpu_generic_to_op((pcp), (val), +=)
 581 # endif
 582 # ifndef __this_cpu_add_8
 583 #  define __this_cpu_add_8(pcp, val)    __this_cpu_generic_to_op((pcp), (val), +=)
 584 # endif
 585 # define __this_cpu_add(pcp, val)       __pcpu_size_call(__this_cpu_add_, (pcp), (val))
 586 #endif
 587
 588 #ifndef __this_cpu_sub
 589 # define __this_cpu_sub(pcp, val)       __this_cpu_add((pcp), -(val))
 590 #endif
 591
 592 #ifndef __this_cpu_inc
 593 # define __this_cpu_inc(pcp)            __this_cpu_add((pcp), 1)
 594 #endif
 595
 596 #ifndef __this_cpu_dec
 597 # define __this_cpu_dec(pcp)            __this_cpu_sub((pcp), 1)
 598 #endif
 599
 600 #ifndef __this_cpu_and
 601 # ifndef __this_cpu_and_1
 602 #  define __this_cpu_and_1(pcp, val)    __this_cpu_generic_to_op((pcp), (val), &=)
 603 # endif
 604 # ifndef __this_cpu_and_2
 605 #  define __this_cpu_and_2(pcp, val)    __this_cpu_generic_to_op((pcp), (val), &=)
 606 # endif
 607 # ifndef __this_cpu_and_4
 608 #  define __this_cpu_and_4(pcp, val)    __this_cpu_generic_to_op((pcp), (val), &=)
 609 # endif
 610 # ifndef __this_cpu_and_8
 611 #  define __this_cpu_and_8(pcp, val)    __this_cpu_generic_to_op((pcp), (val), &=)
 612 # endif
 613 # define __this_cpu_and(pcp, val)       __pcpu_size_call(__this_cpu_and_, (pcp), (val))
 614 #endif
 615
 616 #ifndef __this_cpu_or
 617 # ifndef __this_cpu_or_1
 618 #  define __this_cpu_or_1(pcp, val)     __this_cpu_generic_to_op((pcp), (val), |=)
 619 # endif
 620 # ifndef __this_cpu_or_2
 621 #  define __this_cpu_or_2(pcp, val)     __this_cpu_generic_to_op((pcp), (val), |=)
 622 # endif
 623 # ifndef __this_cpu_or_4
 624 #  define __this_cpu_or_4(pcp, val)     __this_cpu_generic_to_op((pcp), (val), |=)
 625 # endif
 626 # ifndef __this_cpu_or_8
 627 #  define __this_cpu_or_8(pcp, val)     __this_cpu_generic_to_op((pcp), (val), |=)
 628 # endif
 629 # define __this_cpu_or(pcp, val)        __pcpu_size_call(__this_cpu_or_, (pcp), (val))
 630 #endif
 631
 632 #ifndef __this_cpu_xor
 633 # ifndef __this_cpu_xor_1
 634 #  define __this_cpu_xor_1(pcp, val)    __this_cpu_generic_to_op((pcp), (val), ^=)
 635 # endif
 636 # ifndef __this_cpu_xor_2
 637 #  define __this_cpu_xor_2(pcp, val)    __this_cpu_generic_to_op((pcp), (val), ^=)
 638 # endif
 639 # ifndef __this_cpu_xor_4
 640 #  define __this_cpu_xor_4(pcp, val)    __this_cpu_generic_to_op((pcp), (val), ^=)
 641 # endif
 642 # ifndef __this_cpu_xor_8
 643 #  define __this_cpu_xor_8(pcp, val)    __this_cpu_generic_to_op((pcp), (val), ^=)
 644 # endif
 645 # define __this_cpu_xor(pcp, val)       __pcpu_size_call(__this_cpu_xor_, (pcp), (val))
 646 #endif
 647
 648 #define __this_cpu_generic_add_return(pcp, val)                         \
 649 ({                                                                      \
 650         __this_cpu_add(pcp, val);                                       \
 651         __this_cpu_read(pcp);                                           \
 652 })
 653
 654 #ifndef __this_cpu_add_return
 655 # ifndef __this_cpu_add_return_1
 656 #  define __this_cpu_add_return_1(pcp, val)     __this_cpu_generic_add_return(pcp, val)
 657 # endif
 658 # ifndef __this_cpu_add_return_2
 659 #  define __this_cpu_add_return_2(pcp, val)     __this_cpu_generic_add_return(pcp, val)
 660 # endif
 661 # ifndef __this_cpu_add_return_4
 662 #  define __this_cpu_add_return_4(pcp, val)     __this_cpu_generic_add_return(pcp, val)
 663 # endif
 664 # ifndef __this_cpu_add_return_8
 665 #  define __this_cpu_add_return_8(pcp, val)     __this_cpu_generic_add_return(pcp, val)
 666 # endif
 667 # define __this_cpu_add_return(pcp, val)        \
 668         __pcpu_size_call_return2(__this_cpu_add_return_, pcp, val)
 669 #endif
 670
 671 #define __this_cpu_sub_return(pcp, val) __this_cpu_add_return(pcp, -(val))
 672 #define __this_cpu_inc_return(pcp)      __this_cpu_add_return(pcp, 1)
 673 #define __this_cpu_dec_return(pcp)      __this_cpu_add_return(pcp, -1)
 674
 675 #define __this_cpu_generic_xchg(pcp, nval)                              \
 676 ({      typeof(pcp) ret__;                                              \
 677         ret__ = __this_cpu_read(pcp);                                   \
 678         __this_cpu_write(pcp, nval);                                    \
 679         ret__;                                                          \
 680 })
 681
 682 #ifndef __this_cpu_xchg
 683 # ifndef __this_cpu_xchg_1
 684 #  define __this_cpu_xchg_1(pcp, nval)  __this_cpu_generic_xchg(pcp, nval)
 685 # endif
 686 # ifndef __this_cpu_xchg_2
 687 #  define __this_cpu_xchg_2(pcp, nval)  __this_cpu_generic_xchg(pcp, nval)
 688 # endif
 689 # ifndef __this_cpu_xchg_4
 690 #  define __this_cpu_xchg_4(pcp, nval)  __this_cpu_generic_xchg(pcp, nval)
 691 # endif
 692 # ifndef __this_cpu_xchg_8
 693 #  define __this_cpu_xchg_8(pcp, nval)  __this_cpu_generic_xchg(pcp, nval)
 694 # endif
 695 # define __this_cpu_xchg(pcp, nval)     \
 696         __pcpu_size_call_return2(__this_cpu_xchg_, (pcp), nval)
 697 #endif
 698
 699 #define __this_cpu_generic_cmpxchg(pcp, oval, nval)                     \
 700 ({                                                                      \
 701         typeof(pcp) ret__;                                              \
 702         ret__ = __this_cpu_read(pcp);                                   \
 703         if (ret__ == (oval))                                            \
 704                 __this_cpu_write(pcp, nval);                            \
 705         ret__;                                                          \
 706 })
 707
 708 #ifndef __this_cpu_cmpxchg
 709 # ifndef __this_cpu_cmpxchg_1
 710 #  define __this_cpu_cmpxchg_1(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
 711 # endif
 712 # ifndef __this_cpu_cmpxchg_2
 713 #  define __this_cpu_cmpxchg_2(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
 714 # endif
 715 # ifndef __this_cpu_cmpxchg_4
 716 #  define __this_cpu_cmpxchg_4(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
 717 # endif
 718 # ifndef __this_cpu_cmpxchg_8
 719 #  define __this_cpu_cmpxchg_8(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
 720 # endif
 721 # define __this_cpu_cmpxchg(pcp, oval, nval)    \
 722         __pcpu_size_call_return2(__this_cpu_cmpxchg_, pcp, oval, nval)
 723 #endif
 724
 725 #define __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)       \
 726 ({                                                                      \
 727         int __ret = 0;                                                  \
 728         if (__this_cpu_read(pcp1) == (oval1) &&                         \
 729                          __this_cpu_read(pcp2)  == (oval2)) {           \
 730                 __this_cpu_write(pcp1, (nval1));                        \
 731                 __this_cpu_write(pcp2, (nval2));                        \
 732                 __ret = 1;                                              \
 733         }                                                               \
 734         (__ret);                                                        \
 735 })
 736
 737 #ifndef __this_cpu_cmpxchg_double
 738 # ifndef __this_cpu_cmpxchg_double_1
 739 #  define __this_cpu_cmpxchg_double_1(pcp1, pcp2, oval1, oval2, nval1, nval2)   \
 740         __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 741 # endif
 742 # ifndef __this_cpu_cmpxchg_double_2
 743 #  define __this_cpu_cmpxchg_double_2(pcp1, pcp2, oval1, oval2, nval1, nval2)   \
 744         __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 745 # endif
 746 # ifndef __this_cpu_cmpxchg_double_4
 747 #  define __this_cpu_cmpxchg_double_4(pcp1, pcp2, oval1, oval2, nval1, nval2)   \
 748         __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 749 # endif
 750 # ifndef __this_cpu_cmpxchg_double_8
 751 #  define __this_cpu_cmpxchg_double_8(pcp1, pcp2, oval1, oval2, nval1, nval2)   \
 752         __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 753 # endif
 754 # define __this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)      \
 755         __pcpu_double_call_return_bool(__this_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
 756 #endif
 757
 758 #endif /* __LINUX_PERCPU_H */