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), -(typeof(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 #define _this_cpu_generic_add_return(pcp, val)                          \
 379 ({                                                                      \
 380         typeof(pcp) ret__;                                              \
 381         unsigned long flags;                                            \
 382         raw_local_irq_save(flags);                                      \
 383         __this_cpu_add(pcp, val);                                       \
 384         ret__ = __this_cpu_read(pcp);                                   \
 385         raw_local_irq_restore(flags);                                   \
 386         ret__;                                                          \
 387 })
 388
 389 #ifndef this_cpu_add_return
 390 # ifndef this_cpu_add_return_1
 391 #  define this_cpu_add_return_1(pcp, val)       _this_cpu_generic_add_return(pcp, val)
 392 # endif
 393 # ifndef this_cpu_add_return_2
 394 #  define this_cpu_add_return_2(pcp, val)       _this_cpu_generic_add_return(pcp, val)
 395 # endif
 396 # ifndef this_cpu_add_return_4
 397 #  define this_cpu_add_return_4(pcp, val)       _this_cpu_generic_add_return(pcp, val)
 398 # endif
 399 # ifndef this_cpu_add_return_8
 400 #  define this_cpu_add_return_8(pcp, val)       _this_cpu_generic_add_return(pcp, val)
 401 # endif
 402 # define this_cpu_add_return(pcp, val)  __pcpu_size_call_return2(this_cpu_add_return_, pcp, val)
 403 #endif
 404
 405 #define this_cpu_sub_return(pcp, val)   this_cpu_add_return(pcp, -(typeof(pcp))(val))
 406 #define this_cpu_inc_return(pcp)        this_cpu_add_return(pcp, 1)
 407 #define this_cpu_dec_return(pcp)        this_cpu_add_return(pcp, -1)
 408
 409 #define _this_cpu_generic_xchg(pcp, nval)                               \
 410 ({      typeof(pcp) ret__;                                              \
 411         unsigned long flags;                                            \
 412         raw_local_irq_save(flags);                                      \
 413         ret__ = __this_cpu_read(pcp);                                   \
 414         __this_cpu_write(pcp, nval);                                    \
 415         raw_local_irq_restore(flags);                                   \
 416         ret__;                                                          \
 417 })
 418
 419 #ifndef this_cpu_xchg
 420 # ifndef this_cpu_xchg_1
 421 #  define this_cpu_xchg_1(pcp, nval)    _this_cpu_generic_xchg(pcp, nval)
 422 # endif
 423 # ifndef this_cpu_xchg_2
 424 #  define this_cpu_xchg_2(pcp, nval)    _this_cpu_generic_xchg(pcp, nval)
 425 # endif
 426 # ifndef this_cpu_xchg_4
 427 #  define this_cpu_xchg_4(pcp, nval)    _this_cpu_generic_xchg(pcp, nval)
 428 # endif
 429 # ifndef this_cpu_xchg_8
 430 #  define this_cpu_xchg_8(pcp, nval)    _this_cpu_generic_xchg(pcp, nval)
 431 # endif
 432 # define this_cpu_xchg(pcp, nval)       \
 433         __pcpu_size_call_return2(this_cpu_xchg_, (pcp), nval)
 434 #endif
 435
 436 #define _this_cpu_generic_cmpxchg(pcp, oval, nval)                      \
 437 ({                                                                      \
 438         typeof(pcp) ret__;                                              \
 439         unsigned long flags;                                            \
 440         raw_local_irq_save(flags);                                      \
 441         ret__ = __this_cpu_read(pcp);                                   \
 442         if (ret__ == (oval))                                            \
 443                 __this_cpu_write(pcp, nval);                            \
 444         raw_local_irq_restore(flags);                                   \
 445         ret__;                                                          \
 446 })
 447
 448 #ifndef this_cpu_cmpxchg
 449 # ifndef this_cpu_cmpxchg_1
 450 #  define this_cpu_cmpxchg_1(pcp, oval, nval)   _this_cpu_generic_cmpxchg(pcp, oval, nval)
 451 # endif
 452 # ifndef this_cpu_cmpxchg_2
 453 #  define this_cpu_cmpxchg_2(pcp, oval, nval)   _this_cpu_generic_cmpxchg(pcp, oval, nval)
 454 # endif
 455 # ifndef this_cpu_cmpxchg_4
 456 #  define this_cpu_cmpxchg_4(pcp, oval, nval)   _this_cpu_generic_cmpxchg(pcp, oval, nval)
 457 # endif
 458 # ifndef this_cpu_cmpxchg_8
 459 #  define this_cpu_cmpxchg_8(pcp, oval, nval)   _this_cpu_generic_cmpxchg(pcp, oval, nval)
 460 # endif
 461 # define this_cpu_cmpxchg(pcp, oval, nval)      \
 462         __pcpu_size_call_return2(this_cpu_cmpxchg_, pcp, oval, nval)
 463 #endif
 464
 465 /*
 466  * cmpxchg_double replaces two adjacent scalars at once.  The first
 467  * two parameters are per cpu variables which have to be of the same
 468  * size.  A truth value is returned to indicate success or failure
 469  * (since a double register result is difficult to handle).  There is
 470  * very limited hardware support for these operations, so only certain
 471  * sizes may work.
 472  */
 473 #define _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)        \
 474 ({                                                                      \
 475         int ret__;                                                      \
 476         unsigned long flags;                                            \
 477         raw_local_irq_save(flags);                                      \
 478         ret__ = __this_cpu_generic_cmpxchg_double(pcp1, pcp2,           \
 479                         oval1, oval2, nval1, nval2);                    \
 480         raw_local_irq_restore(flags);                                   \
 481         ret__;                                                          \
 482 })
 483
 484 #ifndef this_cpu_cmpxchg_double
 485 # ifndef this_cpu_cmpxchg_double_1
 486 #  define this_cpu_cmpxchg_double_1(pcp1, pcp2, oval1, oval2, nval1, nval2)     \
 487         _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 488 # endif
 489 # ifndef this_cpu_cmpxchg_double_2
 490 #  define this_cpu_cmpxchg_double_2(pcp1, pcp2, oval1, oval2, nval1, nval2)     \
 491         _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 492 # endif
 493 # ifndef this_cpu_cmpxchg_double_4
 494 #  define this_cpu_cmpxchg_double_4(pcp1, pcp2, oval1, oval2, nval1, nval2)     \
 495         _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 496 # endif
 497 # ifndef this_cpu_cmpxchg_double_8
 498 #  define this_cpu_cmpxchg_double_8(pcp1, pcp2, oval1, oval2, nval1, nval2)     \
 499         _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 500 # endif
 501 # define this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)        \
 502         __pcpu_double_call_return_bool(this_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
 503 #endif
 504
 505 /*
 506  * Generic percpu operations for context that are safe from preemption/interrupts.
 507  * Either we do not care about races or the caller has the
 508  * responsibility of handling preemption/interrupt issues. Arch code can still
 509  * override these instructions since the arch per cpu code may be more
 510  * efficient and may actually get race freeness for free (that is the
 511  * case for x86 for example).
 512  *
 513  * If there is no other protection through preempt disable and/or
 514  * disabling interupts then one of these RMW operations can show unexpected
 515  * behavior because the execution thread was rescheduled on another processor
 516  * or an interrupt occurred and the same percpu variable was modified from
 517  * the interrupt context.
 518  */
 519 #ifndef __this_cpu_read
 520 # ifndef __this_cpu_read_1
 521 #  define __this_cpu_read_1(pcp)        (*__this_cpu_ptr(&(pcp)))
 522 # endif
 523 # ifndef __this_cpu_read_2
 524 #  define __this_cpu_read_2(pcp)        (*__this_cpu_ptr(&(pcp)))
 525 # endif
 526 # ifndef __this_cpu_read_4
 527 #  define __this_cpu_read_4(pcp)        (*__this_cpu_ptr(&(pcp)))
 528 # endif
 529 # ifndef __this_cpu_read_8
 530 #  define __this_cpu_read_8(pcp)        (*__this_cpu_ptr(&(pcp)))
 531 # endif
 532 # define __this_cpu_read(pcp)   __pcpu_size_call_return(__this_cpu_read_, (pcp))
 533 #endif
 534
 535 #define __this_cpu_generic_to_op(pcp, val, op)                          \
 536 do {                                                                    \
 537         *__this_cpu_ptr(&(pcp)) op val;                                 \
 538 } while (0)
 539
 540 #ifndef __this_cpu_write
 541 # ifndef __this_cpu_write_1
 542 #  define __this_cpu_write_1(pcp, val)  __this_cpu_generic_to_op((pcp), (val), =)
 543 # endif
 544 # ifndef __this_cpu_write_2
 545 #  define __this_cpu_write_2(pcp, val)  __this_cpu_generic_to_op((pcp), (val), =)
 546 # endif
 547 # ifndef __this_cpu_write_4
 548 #  define __this_cpu_write_4(pcp, val)  __this_cpu_generic_to_op((pcp), (val), =)
 549 # endif
 550 # ifndef __this_cpu_write_8
 551 #  define __this_cpu_write_8(pcp, val)  __this_cpu_generic_to_op((pcp), (val), =)
 552 # endif
 553 # define __this_cpu_write(pcp, val)     __pcpu_size_call(__this_cpu_write_, (pcp), (val))
 554 #endif
 555
 556 #ifndef __this_cpu_add
 557 # ifndef __this_cpu_add_1
 558 #  define __this_cpu_add_1(pcp, val)    __this_cpu_generic_to_op((pcp), (val), +=)
 559 # endif
 560 # ifndef __this_cpu_add_2
 561 #  define __this_cpu_add_2(pcp, val)    __this_cpu_generic_to_op((pcp), (val), +=)
 562 # endif
 563 # ifndef __this_cpu_add_4
 564 #  define __this_cpu_add_4(pcp, val)    __this_cpu_generic_to_op((pcp), (val), +=)
 565 # endif
 566 # ifndef __this_cpu_add_8
 567 #  define __this_cpu_add_8(pcp, val)    __this_cpu_generic_to_op((pcp), (val), +=)
 568 # endif
 569 # define __this_cpu_add(pcp, val)       __pcpu_size_call(__this_cpu_add_, (pcp), (val))
 570 #endif
 571
 572 #ifndef __this_cpu_sub
 573 # define __this_cpu_sub(pcp, val)       __this_cpu_add((pcp), -(typeof(pcp))(val))
 574 #endif
 575
 576 #ifndef __this_cpu_inc
 577 # define __this_cpu_inc(pcp)            __this_cpu_add((pcp), 1)
 578 #endif
 579
 580 #ifndef __this_cpu_dec
 581 # define __this_cpu_dec(pcp)            __this_cpu_sub((pcp), 1)
 582 #endif
 583
 584 #ifndef __this_cpu_and
 585 # ifndef __this_cpu_and_1
 586 #  define __this_cpu_and_1(pcp, val)    __this_cpu_generic_to_op((pcp), (val), &=)
 587 # endif
 588 # ifndef __this_cpu_and_2
 589 #  define __this_cpu_and_2(pcp, val)    __this_cpu_generic_to_op((pcp), (val), &=)
 590 # endif
 591 # ifndef __this_cpu_and_4
 592 #  define __this_cpu_and_4(pcp, val)    __this_cpu_generic_to_op((pcp), (val), &=)
 593 # endif
 594 # ifndef __this_cpu_and_8
 595 #  define __this_cpu_and_8(pcp, val)    __this_cpu_generic_to_op((pcp), (val), &=)
 596 # endif
 597 # define __this_cpu_and(pcp, val)       __pcpu_size_call(__this_cpu_and_, (pcp), (val))
 598 #endif
 599
 600 #ifndef __this_cpu_or
 601 # ifndef __this_cpu_or_1
 602 #  define __this_cpu_or_1(pcp, val)     __this_cpu_generic_to_op((pcp), (val), |=)
 603 # endif
 604 # ifndef __this_cpu_or_2
 605 #  define __this_cpu_or_2(pcp, val)     __this_cpu_generic_to_op((pcp), (val), |=)
 606 # endif
 607 # ifndef __this_cpu_or_4
 608 #  define __this_cpu_or_4(pcp, val)     __this_cpu_generic_to_op((pcp), (val), |=)
 609 # endif
 610 # ifndef __this_cpu_or_8
 611 #  define __this_cpu_or_8(pcp, val)     __this_cpu_generic_to_op((pcp), (val), |=)
 612 # endif
 613 # define __this_cpu_or(pcp, val)        __pcpu_size_call(__this_cpu_or_, (pcp), (val))
 614 #endif
 615
 616 #define __this_cpu_generic_add_return(pcp, val)                         \
 617 ({                                                                      \
 618         __this_cpu_add(pcp, val);                                       \
 619         __this_cpu_read(pcp);                                           \
 620 })
 621
 622 #ifndef __this_cpu_add_return
 623 # ifndef __this_cpu_add_return_1
 624 #  define __this_cpu_add_return_1(pcp, val)     __this_cpu_generic_add_return(pcp, val)
 625 # endif
 626 # ifndef __this_cpu_add_return_2
 627 #  define __this_cpu_add_return_2(pcp, val)     __this_cpu_generic_add_return(pcp, val)
 628 # endif
 629 # ifndef __this_cpu_add_return_4
 630 #  define __this_cpu_add_return_4(pcp, val)     __this_cpu_generic_add_return(pcp, val)
 631 # endif
 632 # ifndef __this_cpu_add_return_8
 633 #  define __this_cpu_add_return_8(pcp, val)     __this_cpu_generic_add_return(pcp, val)
 634 # endif
 635 # define __this_cpu_add_return(pcp, val)        \
 636         __pcpu_size_call_return2(__this_cpu_add_return_, pcp, val)
 637 #endif
 638
 639 #define __this_cpu_sub_return(pcp, val) __this_cpu_add_return(pcp, -(typeof(pcp))(val))
 640 #define __this_cpu_inc_return(pcp)      __this_cpu_add_return(pcp, 1)
 641 #define __this_cpu_dec_return(pcp)      __this_cpu_add_return(pcp, -1)
 642
 643 #define __this_cpu_generic_xchg(pcp, nval)                              \
 644 ({      typeof(pcp) ret__;                                              \
 645         ret__ = __this_cpu_read(pcp);                                   \
 646         __this_cpu_write(pcp, nval);                                    \
 647         ret__;                                                          \
 648 })
 649
 650 #ifndef __this_cpu_xchg
 651 # ifndef __this_cpu_xchg_1
 652 #  define __this_cpu_xchg_1(pcp, nval)  __this_cpu_generic_xchg(pcp, nval)
 653 # endif
 654 # ifndef __this_cpu_xchg_2
 655 #  define __this_cpu_xchg_2(pcp, nval)  __this_cpu_generic_xchg(pcp, nval)
 656 # endif
 657 # ifndef __this_cpu_xchg_4
 658 #  define __this_cpu_xchg_4(pcp, nval)  __this_cpu_generic_xchg(pcp, nval)
 659 # endif
 660 # ifndef __this_cpu_xchg_8
 661 #  define __this_cpu_xchg_8(pcp, nval)  __this_cpu_generic_xchg(pcp, nval)
 662 # endif
 663 # define __this_cpu_xchg(pcp, nval)     \
 664         __pcpu_size_call_return2(__this_cpu_xchg_, (pcp), nval)
 665 #endif
 666
 667 #define __this_cpu_generic_cmpxchg(pcp, oval, nval)                     \
 668 ({                                                                      \
 669         typeof(pcp) ret__;                                              \
 670         ret__ = __this_cpu_read(pcp);                                   \
 671         if (ret__ == (oval))                                            \
 672                 __this_cpu_write(pcp, nval);                            \
 673         ret__;                                                          \
 674 })
 675
 676 #ifndef __this_cpu_cmpxchg
 677 # ifndef __this_cpu_cmpxchg_1
 678 #  define __this_cpu_cmpxchg_1(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
 679 # endif
 680 # ifndef __this_cpu_cmpxchg_2
 681 #  define __this_cpu_cmpxchg_2(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
 682 # endif
 683 # ifndef __this_cpu_cmpxchg_4
 684 #  define __this_cpu_cmpxchg_4(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
 685 # endif
 686 # ifndef __this_cpu_cmpxchg_8
 687 #  define __this_cpu_cmpxchg_8(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
 688 # endif
 689 # define __this_cpu_cmpxchg(pcp, oval, nval)    \
 690         __pcpu_size_call_return2(__this_cpu_cmpxchg_, pcp, oval, nval)
 691 #endif
 692
 693 #define __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)       \
 694 ({                                                                      \
 695         int __ret = 0;                                                  \
 696         if (__this_cpu_read(pcp1) == (oval1) &&                         \
 697                          __this_cpu_read(pcp2)  == (oval2)) {           \
 698                 __this_cpu_write(pcp1, (nval1));                        \
 699                 __this_cpu_write(pcp2, (nval2));                        \
 700                 __ret = 1;                                              \
 701         }                                                               \
 702         (__ret);                                                        \
 703 })
 704
 705 #ifndef __this_cpu_cmpxchg_double
 706 # ifndef __this_cpu_cmpxchg_double_1
 707 #  define __this_cpu_cmpxchg_double_1(pcp1, pcp2, oval1, oval2, nval1, nval2)   \
 708         __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 709 # endif
 710 # ifndef __this_cpu_cmpxchg_double_2
 711 #  define __this_cpu_cmpxchg_double_2(pcp1, pcp2, oval1, oval2, nval1, nval2)   \
 712         __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 713 # endif
 714 # ifndef __this_cpu_cmpxchg_double_4
 715 #  define __this_cpu_cmpxchg_double_4(pcp1, pcp2, oval1, oval2, nval1, nval2)   \
 716         __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 717 # endif
 718 # ifndef __this_cpu_cmpxchg_double_8
 719 #  define __this_cpu_cmpxchg_double_8(pcp1, pcp2, oval1, oval2, nval1, nval2)   \
 720         __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 721 # endif
 722 # define __this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)      \
 723         __pcpu_double_call_return_bool(__this_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
 724 #endif
 725
 726 #endif /* __LINUX_PERCPU_H */