include/linux/percpu.h

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