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 *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  * Optional methods for optimized non-lvalue per-cpu variable access.
 170  *
 171  * @var can be a percpu variable or a field of it and its size should
 172  * equal char, int or long.  percpu_read() evaluates to a lvalue and
 173  * all others to void.
 174  *
 175  * These operations are guaranteed to be atomic.
 176  * The generic versions disable interrupts.  Archs are
 177  * encouraged to implement single-instruction alternatives which don't
 178  * require protection.
 179  */
 180 #ifndef percpu_read
 181 # define percpu_read(var)                                               \
 182   ({                                                                    \
 183         typeof(var) *pr_ptr__ = &(var);                                 \
 184         typeof(var) pr_ret__;                                           \
 185         pr_ret__ = get_cpu_var(*pr_ptr__);                              \
 186         put_cpu_var(*pr_ptr__);                                         \
 187         pr_ret__;                                                       \
 188   })
 189 #endif
 190
 191 #define __percpu_generic_to_op(var, val, op)                            \
 192 do {                                                                    \
 193         typeof(var) *pgto_ptr__ = &(var);                               \
 194         get_cpu_var(*pgto_ptr__) op val;                                \
 195         put_cpu_var(*pgto_ptr__);                                       \
 196 } while (0)
 197
 198 #ifndef percpu_write
 199 # define percpu_write(var, val)         __percpu_generic_to_op(var, (val), =)
 200 #endif
 201
 202 #ifndef percpu_add
 203 # define percpu_add(var, val)           __percpu_generic_to_op(var, (val), +=)
 204 #endif
 205
 206 #ifndef percpu_sub
 207 # define percpu_sub(var, val)           __percpu_generic_to_op(var, (val), -=)
 208 #endif
 209
 210 #ifndef percpu_and
 211 # define percpu_and(var, val)           __percpu_generic_to_op(var, (val), &=)
 212 #endif
 213
 214 #ifndef percpu_or
 215 # define percpu_or(var, val)            __percpu_generic_to_op(var, (val), |=)
 216 #endif
 217
 218 #ifndef percpu_xor
 219 # define percpu_xor(var, val)           __percpu_generic_to_op(var, (val), ^=)
 220 #endif
 221
 222 /*
 223  * Branching function to split up a function into a set of functions that
 224  * are called for different scalar sizes of the objects handled.
 225  */
 226
 227 extern void __bad_size_call_parameter(void);
 228
 229 #define __pcpu_size_call_return(stem, variable)                         \
 230 ({      typeof(variable) pscr_ret__;                                    \
 231         __verify_pcpu_ptr(&(variable));                                 \
 232         switch(sizeof(variable)) {                                      \
 233         case 1: pscr_ret__ = stem##1(variable);break;                   \
 234         case 2: pscr_ret__ = stem##2(variable);break;                   \
 235         case 4: pscr_ret__ = stem##4(variable);break;                   \
 236         case 8: pscr_ret__ = stem##8(variable);break;                   \
 237         default:                                                        \
 238                 __bad_size_call_parameter();break;                      \
 239         }                                                               \
 240         pscr_ret__;                                                     \
 241 })
 242
 243 #define __pcpu_size_call_return2(stem, variable, ...)                   \
 244 ({                                                                      \
 245         typeof(variable) pscr2_ret__;                                   \
 246         __verify_pcpu_ptr(&(variable));                                 \
 247         switch(sizeof(variable)) {                                      \
 248         case 1: pscr2_ret__ = stem##1(variable, __VA_ARGS__); break;    \
 249         case 2: pscr2_ret__ = stem##2(variable, __VA_ARGS__); break;    \
 250         case 4: pscr2_ret__ = stem##4(variable, __VA_ARGS__); break;    \
 251         case 8: pscr2_ret__ = stem##8(variable, __VA_ARGS__); break;    \
 252         default:                                                        \
 253                 __bad_size_call_parameter(); break;                     \
 254         }                                                               \
 255         pscr2_ret__;                                                    \
 256 })
 257
 258 /*
 259  * Special handling for cmpxchg_double.  cmpxchg_double is passed two
 260  * percpu variables.  The first has to be aligned to a double word
 261  * boundary and the second has to follow directly thereafter.
 262  * We enforce this on all architectures even if they don't support
 263  * a double cmpxchg instruction, since it's a cheap requirement, and it
 264  * avoids breaking the requirement for architectures with the instruction.
 265  */
 266 #define __pcpu_double_call_return_bool(stem, pcp1, pcp2, ...)           \
 267 ({                                                                      \
 268         bool pdcrb_ret__;                                               \
 269         __verify_pcpu_ptr(&pcp1);                                       \
 270         BUILD_BUG_ON(sizeof(pcp1) != sizeof(pcp2));                     \
 271         VM_BUG_ON((unsigned long)(&pcp1) % (2 * sizeof(pcp1)));         \
 272         VM_BUG_ON((unsigned long)(&pcp2) !=                             \
 273                   (unsigned long)(&pcp1) + sizeof(pcp1));               \
 274         switch(sizeof(pcp1)) {                                          \
 275         case 1: pdcrb_ret__ = stem##1(pcp1, pcp2, __VA_ARGS__); break;  \
 276         case 2: pdcrb_ret__ = stem##2(pcp1, pcp2, __VA_ARGS__); break;  \
 277         case 4: pdcrb_ret__ = stem##4(pcp1, pcp2, __VA_ARGS__); break;  \
 278         case 8: pdcrb_ret__ = stem##8(pcp1, pcp2, __VA_ARGS__); break;  \
 279         default:                                                        \
 280                 __bad_size_call_parameter(); break;                     \
 281         }                                                               \
 282         pdcrb_ret__;                                                    \
 283 })
 284
 285 #define __pcpu_size_call(stem, variable, ...)                           \
 286 do {                                                                    \
 287         __verify_pcpu_ptr(&(variable));                                 \
 288         switch(sizeof(variable)) {                                      \
 289                 case 1: stem##1(variable, __VA_ARGS__);break;           \
 290                 case 2: stem##2(variable, __VA_ARGS__);break;           \
 291                 case 4: stem##4(variable, __VA_ARGS__);break;           \
 292                 case 8: stem##8(variable, __VA_ARGS__);break;           \
 293                 default:                                                \
 294                         __bad_size_call_parameter();break;              \
 295         }                                                               \
 296 } while (0)
 297
 298 /*
 299  * Optimized manipulation for memory allocated through the per cpu
 300  * allocator or for addresses of per cpu variables.
 301  *
 302  * These operation guarantee exclusivity of access for other operations
 303  * on the *same* processor. The assumption is that per cpu data is only
 304  * accessed by a single processor instance (the current one).
 305  *
 306  * The first group is used for accesses that must be done in a
 307  * preemption safe way since we know that the context is not preempt
 308  * safe. Interrupts may occur. If the interrupt modifies the variable
 309  * too then RMW actions will not be reliable.
 310  *
 311  * The arch code can provide optimized functions in two ways:
 312  *
 313  * 1. Override the function completely. F.e. define this_cpu_add().
 314  *    The arch must then ensure that the various scalar format passed
 315  *    are handled correctly.
 316  *
 317  * 2. Provide functions for certain scalar sizes. F.e. provide
 318  *    this_cpu_add_2() to provide per cpu atomic operations for 2 byte
 319  *    sized RMW actions. If arch code does not provide operations for
 320  *    a scalar size then the fallback in the generic code will be
 321  *    used.
 322  */
 323
 324 #define _this_cpu_generic_read(pcp)                                     \
 325 ({      typeof(pcp) ret__;                                              \
 326         preempt_disable();                                              \
 327         ret__ = *this_cpu_ptr(&(pcp));                                  \
 328         preempt_enable();                                               \
 329         ret__;                                                          \
 330 })
 331
 332 #ifndef this_cpu_read
 333 # ifndef this_cpu_read_1
 334 #  define this_cpu_read_1(pcp)  _this_cpu_generic_read(pcp)
 335 # endif
 336 # ifndef this_cpu_read_2
 337 #  define this_cpu_read_2(pcp)  _this_cpu_generic_read(pcp)
 338 # endif
 339 # ifndef this_cpu_read_4
 340 #  define this_cpu_read_4(pcp)  _this_cpu_generic_read(pcp)
 341 # endif
 342 # ifndef this_cpu_read_8
 343 #  define this_cpu_read_8(pcp)  _this_cpu_generic_read(pcp)
 344 # endif
 345 # define this_cpu_read(pcp)     __pcpu_size_call_return(this_cpu_read_, (pcp))
 346 #endif
 347
 348 #define _this_cpu_generic_to_op(pcp, val, op)                           \
 349 do {                                                                    \
 350         unsigned long flags;                                            \
 351         raw_local_irq_save(flags);                                      \
 352         *__this_cpu_ptr(&(pcp)) op val;                                 \
 353         raw_local_irq_restore(flags);                                   \
 354 } while (0)
 355
 356 #ifndef this_cpu_write
 357 # ifndef this_cpu_write_1
 358 #  define this_cpu_write_1(pcp, val)    _this_cpu_generic_to_op((pcp), (val), =)
 359 # endif
 360 # ifndef this_cpu_write_2
 361 #  define this_cpu_write_2(pcp, val)    _this_cpu_generic_to_op((pcp), (val), =)
 362 # endif
 363 # ifndef this_cpu_write_4
 364 #  define this_cpu_write_4(pcp, val)    _this_cpu_generic_to_op((pcp), (val), =)
 365 # endif
 366 # ifndef this_cpu_write_8
 367 #  define this_cpu_write_8(pcp, val)    _this_cpu_generic_to_op((pcp), (val), =)
 368 # endif
 369 # define this_cpu_write(pcp, val)       __pcpu_size_call(this_cpu_write_, (pcp), (val))
 370 #endif
 371
 372 #ifndef this_cpu_add
 373 # ifndef this_cpu_add_1
 374 #  define this_cpu_add_1(pcp, val)      _this_cpu_generic_to_op((pcp), (val), +=)
 375 # endif
 376 # ifndef this_cpu_add_2
 377 #  define this_cpu_add_2(pcp, val)      _this_cpu_generic_to_op((pcp), (val), +=)
 378 # endif
 379 # ifndef this_cpu_add_4
 380 #  define this_cpu_add_4(pcp, val)      _this_cpu_generic_to_op((pcp), (val), +=)
 381 # endif
 382 # ifndef this_cpu_add_8
 383 #  define this_cpu_add_8(pcp, val)      _this_cpu_generic_to_op((pcp), (val), +=)
 384 # endif
 385 # define this_cpu_add(pcp, val)         __pcpu_size_call(this_cpu_add_, (pcp), (val))
 386 #endif
 387
 388 #ifndef this_cpu_sub
 389 # define this_cpu_sub(pcp, val)         this_cpu_add((pcp), -(val))
 390 #endif
 391
 392 #ifndef this_cpu_inc
 393 # define this_cpu_inc(pcp)              this_cpu_add((pcp), 1)
 394 #endif
 395
 396 #ifndef this_cpu_dec
 397 # define this_cpu_dec(pcp)              this_cpu_sub((pcp), 1)
 398 #endif
 399
 400 #ifndef this_cpu_and
 401 # ifndef this_cpu_and_1
 402 #  define this_cpu_and_1(pcp, val)      _this_cpu_generic_to_op((pcp), (val), &=)
 403 # endif
 404 # ifndef this_cpu_and_2
 405 #  define this_cpu_and_2(pcp, val)      _this_cpu_generic_to_op((pcp), (val), &=)
 406 # endif
 407 # ifndef this_cpu_and_4
 408 #  define this_cpu_and_4(pcp, val)      _this_cpu_generic_to_op((pcp), (val), &=)
 409 # endif
 410 # ifndef this_cpu_and_8
 411 #  define this_cpu_and_8(pcp, val)      _this_cpu_generic_to_op((pcp), (val), &=)
 412 # endif
 413 # define this_cpu_and(pcp, val)         __pcpu_size_call(this_cpu_and_, (pcp), (val))
 414 #endif
 415
 416 #ifndef this_cpu_or
 417 # ifndef this_cpu_or_1
 418 #  define this_cpu_or_1(pcp, val)       _this_cpu_generic_to_op((pcp), (val), |=)
 419 # endif
 420 # ifndef this_cpu_or_2
 421 #  define this_cpu_or_2(pcp, val)       _this_cpu_generic_to_op((pcp), (val), |=)
 422 # endif
 423 # ifndef this_cpu_or_4
 424 #  define this_cpu_or_4(pcp, val)       _this_cpu_generic_to_op((pcp), (val), |=)
 425 # endif
 426 # ifndef this_cpu_or_8
 427 #  define this_cpu_or_8(pcp, val)       _this_cpu_generic_to_op((pcp), (val), |=)
 428 # endif
 429 # define this_cpu_or(pcp, val)          __pcpu_size_call(this_cpu_or_, (pcp), (val))
 430 #endif
 431
 432 #ifndef this_cpu_xor
 433 # ifndef this_cpu_xor_1
 434 #  define this_cpu_xor_1(pcp, val)      _this_cpu_generic_to_op((pcp), (val), ^=)
 435 # endif
 436 # ifndef this_cpu_xor_2
 437 #  define this_cpu_xor_2(pcp, val)      _this_cpu_generic_to_op((pcp), (val), ^=)
 438 # endif
 439 # ifndef this_cpu_xor_4
 440 #  define this_cpu_xor_4(pcp, val)      _this_cpu_generic_to_op((pcp), (val), ^=)
 441 # endif
 442 # ifndef this_cpu_xor_8
 443 #  define this_cpu_xor_8(pcp, val)      _this_cpu_generic_to_op((pcp), (val), ^=)
 444 # endif
 445 # define this_cpu_xor(pcp, val)         __pcpu_size_call(this_cpu_or_, (pcp), (val))
 446 #endif
 447
 448 #define _this_cpu_generic_add_return(pcp, val)                          \
 449 ({                                                                      \
 450         typeof(pcp) ret__;                                              \
 451         unsigned long flags;                                            \
 452         raw_local_irq_save(flags);                                      \
 453         __this_cpu_add(pcp, val);                                       \
 454         ret__ = __this_cpu_read(pcp);                                   \
 455         raw_local_irq_restore(flags);                                   \
 456         ret__;                                                          \
 457 })
 458
 459 #ifndef this_cpu_add_return
 460 # ifndef this_cpu_add_return_1
 461 #  define this_cpu_add_return_1(pcp, val)       _this_cpu_generic_add_return(pcp, val)
 462 # endif
 463 # ifndef this_cpu_add_return_2
 464 #  define this_cpu_add_return_2(pcp, val)       _this_cpu_generic_add_return(pcp, val)
 465 # endif
 466 # ifndef this_cpu_add_return_4
 467 #  define this_cpu_add_return_4(pcp, val)       _this_cpu_generic_add_return(pcp, val)
 468 # endif
 469 # ifndef this_cpu_add_return_8
 470 #  define this_cpu_add_return_8(pcp, val)       _this_cpu_generic_add_return(pcp, val)
 471 # endif
 472 # define this_cpu_add_return(pcp, val)  __pcpu_size_call_return2(this_cpu_add_return_, pcp, val)
 473 #endif
 474
 475 #define this_cpu_sub_return(pcp, val)   this_cpu_add_return(pcp, -(val))
 476 #define this_cpu_inc_return(pcp)        this_cpu_add_return(pcp, 1)
 477 #define this_cpu_dec_return(pcp)        this_cpu_add_return(pcp, -1)
 478
 479 #define _this_cpu_generic_xchg(pcp, nval)                               \
 480 ({      typeof(pcp) ret__;                                              \
 481         unsigned long flags;                                            \
 482         raw_local_irq_save(flags);                                      \
 483         ret__ = __this_cpu_read(pcp);                                   \
 484         __this_cpu_write(pcp, nval);                                    \
 485         raw_local_irq_restore(flags);                                   \
 486         ret__;                                                          \
 487 })
 488
 489 #ifndef this_cpu_xchg
 490 # ifndef this_cpu_xchg_1
 491 #  define this_cpu_xchg_1(pcp, nval)    _this_cpu_generic_xchg(pcp, nval)
 492 # endif
 493 # ifndef this_cpu_xchg_2
 494 #  define this_cpu_xchg_2(pcp, nval)    _this_cpu_generic_xchg(pcp, nval)
 495 # endif
 496 # ifndef this_cpu_xchg_4
 497 #  define this_cpu_xchg_4(pcp, nval)    _this_cpu_generic_xchg(pcp, nval)
 498 # endif
 499 # ifndef this_cpu_xchg_8
 500 #  define this_cpu_xchg_8(pcp, nval)    _this_cpu_generic_xchg(pcp, nval)
 501 # endif
 502 # define this_cpu_xchg(pcp, nval)       \
 503         __pcpu_size_call_return2(this_cpu_xchg_, (pcp), nval)
 504 #endif
 505
 506 #define _this_cpu_generic_cmpxchg(pcp, oval, nval)                      \
 507 ({                                                                      \
 508         typeof(pcp) ret__;                                              \
 509         unsigned long flags;                                            \
 510         raw_local_irq_save(flags);                                      \
 511         ret__ = __this_cpu_read(pcp);                                   \
 512         if (ret__ == (oval))                                            \
 513                 __this_cpu_write(pcp, nval);                            \
 514         raw_local_irq_restore(flags);                                   \
 515         ret__;                                                          \
 516 })
 517
 518 #ifndef this_cpu_cmpxchg
 519 # ifndef this_cpu_cmpxchg_1
 520 #  define this_cpu_cmpxchg_1(pcp, oval, nval)   _this_cpu_generic_cmpxchg(pcp, oval, nval)
 521 # endif
 522 # ifndef this_cpu_cmpxchg_2
 523 #  define this_cpu_cmpxchg_2(pcp, oval, nval)   _this_cpu_generic_cmpxchg(pcp, oval, nval)
 524 # endif
 525 # ifndef this_cpu_cmpxchg_4
 526 #  define this_cpu_cmpxchg_4(pcp, oval, nval)   _this_cpu_generic_cmpxchg(pcp, oval, nval)
 527 # endif
 528 # ifndef this_cpu_cmpxchg_8
 529 #  define this_cpu_cmpxchg_8(pcp, oval, nval)   _this_cpu_generic_cmpxchg(pcp, oval, nval)
 530 # endif
 531 # define this_cpu_cmpxchg(pcp, oval, nval)      \
 532         __pcpu_size_call_return2(this_cpu_cmpxchg_, pcp, oval, nval)
 533 #endif
 534
 535 /*
 536  * cmpxchg_double replaces two adjacent scalars at once.  The first
 537  * two parameters are per cpu variables which have to be of the same
 538  * size.  A truth value is returned to indicate success or failure
 539  * (since a double register result is difficult to handle).  There is
 540  * very limited hardware support for these operations, so only certain
 541  * sizes may work.
 542  */
 543 #define _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)        \
 544 ({                                                                      \
 545         int ret__;                                                      \
 546         unsigned long flags;                                            \
 547         raw_local_irq_save(flags);                                      \
 548         ret__ = __this_cpu_generic_cmpxchg_double(pcp1, pcp2,           \
 549                         oval1, oval2, nval1, nval2);                    \
 550         raw_local_irq_restore(flags);                                   \
 551         ret__;                                                          \
 552 })
 553
 554 #ifndef this_cpu_cmpxchg_double
 555 # ifndef this_cpu_cmpxchg_double_1
 556 #  define this_cpu_cmpxchg_double_1(pcp1, pcp2, oval1, oval2, nval1, nval2)     \
 557         _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 558 # endif
 559 # ifndef this_cpu_cmpxchg_double_2
 560 #  define this_cpu_cmpxchg_double_2(pcp1, pcp2, oval1, oval2, nval1, nval2)     \
 561         _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 562 # endif
 563 # ifndef this_cpu_cmpxchg_double_4
 564 #  define this_cpu_cmpxchg_double_4(pcp1, pcp2, oval1, oval2, nval1, nval2)     \
 565         _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 566 # endif
 567 # ifndef this_cpu_cmpxchg_double_8
 568 #  define this_cpu_cmpxchg_double_8(pcp1, pcp2, oval1, oval2, nval1, nval2)     \
 569         _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 570 # endif
 571 # define this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)        \
 572         __pcpu_double_call_return_bool(this_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
 573 #endif
 574
 575 /*
 576  * Generic percpu operations for context that are safe from preemption/interrupts.
 577  * Either we do not care about races or the caller has the
 578  * responsibility of handling preemption/interrupt issues. Arch code can still
 579  * override these instructions since the arch per cpu code may be more
 580  * efficient and may actually get race freeness for free (that is the
 581  * case for x86 for example).
 582  *
 583  * If there is no other protection through preempt disable and/or
 584  * disabling interupts then one of these RMW operations can show unexpected
 585  * behavior because the execution thread was rescheduled on another processor
 586  * or an interrupt occurred and the same percpu variable was modified from
 587  * the interrupt context.
 588  */
 589 #ifndef __this_cpu_read
 590 # ifndef __this_cpu_read_1
 591 #  define __this_cpu_read_1(pcp)        (*__this_cpu_ptr(&(pcp)))
 592 # endif
 593 # ifndef __this_cpu_read_2
 594 #  define __this_cpu_read_2(pcp)        (*__this_cpu_ptr(&(pcp)))
 595 # endif
 596 # ifndef __this_cpu_read_4
 597 #  define __this_cpu_read_4(pcp)        (*__this_cpu_ptr(&(pcp)))
 598 # endif
 599 # ifndef __this_cpu_read_8
 600 #  define __this_cpu_read_8(pcp)        (*__this_cpu_ptr(&(pcp)))
 601 # endif
 602 # define __this_cpu_read(pcp)   __pcpu_size_call_return(__this_cpu_read_, (pcp))
 603 #endif
 604
 605 #define __this_cpu_generic_to_op(pcp, val, op)                          \
 606 do {                                                                    \
 607         *__this_cpu_ptr(&(pcp)) op val;                                 \
 608 } while (0)
 609
 610 #ifndef __this_cpu_write
 611 # ifndef __this_cpu_write_1
 612 #  define __this_cpu_write_1(pcp, val)  __this_cpu_generic_to_op((pcp), (val), =)
 613 # endif
 614 # ifndef __this_cpu_write_2
 615 #  define __this_cpu_write_2(pcp, val)  __this_cpu_generic_to_op((pcp), (val), =)
 616 # endif
 617 # ifndef __this_cpu_write_4
 618 #  define __this_cpu_write_4(pcp, val)  __this_cpu_generic_to_op((pcp), (val), =)
 619 # endif
 620 # ifndef __this_cpu_write_8
 621 #  define __this_cpu_write_8(pcp, val)  __this_cpu_generic_to_op((pcp), (val), =)
 622 # endif
 623 # define __this_cpu_write(pcp, val)     __pcpu_size_call(__this_cpu_write_, (pcp), (val))
 624 #endif
 625
 626 #ifndef __this_cpu_add
 627 # ifndef __this_cpu_add_1
 628 #  define __this_cpu_add_1(pcp, val)    __this_cpu_generic_to_op((pcp), (val), +=)
 629 # endif
 630 # ifndef __this_cpu_add_2
 631 #  define __this_cpu_add_2(pcp, val)    __this_cpu_generic_to_op((pcp), (val), +=)
 632 # endif
 633 # ifndef __this_cpu_add_4
 634 #  define __this_cpu_add_4(pcp, val)    __this_cpu_generic_to_op((pcp), (val), +=)
 635 # endif
 636 # ifndef __this_cpu_add_8
 637 #  define __this_cpu_add_8(pcp, val)    __this_cpu_generic_to_op((pcp), (val), +=)
 638 # endif
 639 # define __this_cpu_add(pcp, val)       __pcpu_size_call(__this_cpu_add_, (pcp), (val))
 640 #endif
 641
 642 #ifndef __this_cpu_sub
 643 # define __this_cpu_sub(pcp, val)       __this_cpu_add((pcp), -(val))
 644 #endif
 645
 646 #ifndef __this_cpu_inc
 647 # define __this_cpu_inc(pcp)            __this_cpu_add((pcp), 1)
 648 #endif
 649
 650 #ifndef __this_cpu_dec
 651 # define __this_cpu_dec(pcp)            __this_cpu_sub((pcp), 1)
 652 #endif
 653
 654 #ifndef __this_cpu_and
 655 # ifndef __this_cpu_and_1
 656 #  define __this_cpu_and_1(pcp, val)    __this_cpu_generic_to_op((pcp), (val), &=)
 657 # endif
 658 # ifndef __this_cpu_and_2
 659 #  define __this_cpu_and_2(pcp, val)    __this_cpu_generic_to_op((pcp), (val), &=)
 660 # endif
 661 # ifndef __this_cpu_and_4
 662 #  define __this_cpu_and_4(pcp, val)    __this_cpu_generic_to_op((pcp), (val), &=)
 663 # endif
 664 # ifndef __this_cpu_and_8
 665 #  define __this_cpu_and_8(pcp, val)    __this_cpu_generic_to_op((pcp), (val), &=)
 666 # endif
 667 # define __this_cpu_and(pcp, val)       __pcpu_size_call(__this_cpu_and_, (pcp), (val))
 668 #endif
 669
 670 #ifndef __this_cpu_or
 671 # ifndef __this_cpu_or_1
 672 #  define __this_cpu_or_1(pcp, val)     __this_cpu_generic_to_op((pcp), (val), |=)
 673 # endif
 674 # ifndef __this_cpu_or_2
 675 #  define __this_cpu_or_2(pcp, val)     __this_cpu_generic_to_op((pcp), (val), |=)
 676 # endif
 677 # ifndef __this_cpu_or_4
 678 #  define __this_cpu_or_4(pcp, val)     __this_cpu_generic_to_op((pcp), (val), |=)
 679 # endif
 680 # ifndef __this_cpu_or_8
 681 #  define __this_cpu_or_8(pcp, val)     __this_cpu_generic_to_op((pcp), (val), |=)
 682 # endif
 683 # define __this_cpu_or(pcp, val)        __pcpu_size_call(__this_cpu_or_, (pcp), (val))
 684 #endif
 685
 686 #ifndef __this_cpu_xor
 687 # ifndef __this_cpu_xor_1
 688 #  define __this_cpu_xor_1(pcp, val)    __this_cpu_generic_to_op((pcp), (val), ^=)
 689 # endif
 690 # ifndef __this_cpu_xor_2
 691 #  define __this_cpu_xor_2(pcp, val)    __this_cpu_generic_to_op((pcp), (val), ^=)
 692 # endif
 693 # ifndef __this_cpu_xor_4
 694 #  define __this_cpu_xor_4(pcp, val)    __this_cpu_generic_to_op((pcp), (val), ^=)
 695 # endif
 696 # ifndef __this_cpu_xor_8
 697 #  define __this_cpu_xor_8(pcp, val)    __this_cpu_generic_to_op((pcp), (val), ^=)
 698 # endif
 699 # define __this_cpu_xor(pcp, val)       __pcpu_size_call(__this_cpu_xor_, (pcp), (val))
 700 #endif
 701
 702 #define __this_cpu_generic_add_return(pcp, val)                         \
 703 ({                                                                      \
 704         __this_cpu_add(pcp, val);                                       \
 705         __this_cpu_read(pcp);                                           \
 706 })
 707
 708 #ifndef __this_cpu_add_return
 709 # ifndef __this_cpu_add_return_1
 710 #  define __this_cpu_add_return_1(pcp, val)     __this_cpu_generic_add_return(pcp, val)
 711 # endif
 712 # ifndef __this_cpu_add_return_2
 713 #  define __this_cpu_add_return_2(pcp, val)     __this_cpu_generic_add_return(pcp, val)
 714 # endif
 715 # ifndef __this_cpu_add_return_4
 716 #  define __this_cpu_add_return_4(pcp, val)     __this_cpu_generic_add_return(pcp, val)
 717 # endif
 718 # ifndef __this_cpu_add_return_8
 719 #  define __this_cpu_add_return_8(pcp, val)     __this_cpu_generic_add_return(pcp, val)
 720 # endif
 721 # define __this_cpu_add_return(pcp, val)        \
 722         __pcpu_size_call_return2(__this_cpu_add_return_, pcp, val)
 723 #endif
 724
 725 #define __this_cpu_sub_return(pcp, val) __this_cpu_add_return(pcp, -(val))
 726 #define __this_cpu_inc_return(pcp)      __this_cpu_add_return(pcp, 1)
 727 #define __this_cpu_dec_return(pcp)      __this_cpu_add_return(pcp, -1)
 728
 729 #define __this_cpu_generic_xchg(pcp, nval)                              \
 730 ({      typeof(pcp) ret__;                                              \
 731         ret__ = __this_cpu_read(pcp);                                   \
 732         __this_cpu_write(pcp, nval);                                    \
 733         ret__;                                                          \
 734 })
 735
 736 #ifndef __this_cpu_xchg
 737 # ifndef __this_cpu_xchg_1
 738 #  define __this_cpu_xchg_1(pcp, nval)  __this_cpu_generic_xchg(pcp, nval)
 739 # endif
 740 # ifndef __this_cpu_xchg_2
 741 #  define __this_cpu_xchg_2(pcp, nval)  __this_cpu_generic_xchg(pcp, nval)
 742 # endif
 743 # ifndef __this_cpu_xchg_4
 744 #  define __this_cpu_xchg_4(pcp, nval)  __this_cpu_generic_xchg(pcp, nval)
 745 # endif
 746 # ifndef __this_cpu_xchg_8
 747 #  define __this_cpu_xchg_8(pcp, nval)  __this_cpu_generic_xchg(pcp, nval)
 748 # endif
 749 # define __this_cpu_xchg(pcp, nval)     \
 750         __pcpu_size_call_return2(__this_cpu_xchg_, (pcp), nval)
 751 #endif
 752
 753 #define __this_cpu_generic_cmpxchg(pcp, oval, nval)                     \
 754 ({                                                                      \
 755         typeof(pcp) ret__;                                              \
 756         ret__ = __this_cpu_read(pcp);                                   \
 757         if (ret__ == (oval))                                            \
 758                 __this_cpu_write(pcp, nval);                            \
 759         ret__;                                                          \
 760 })
 761
 762 #ifndef __this_cpu_cmpxchg
 763 # ifndef __this_cpu_cmpxchg_1
 764 #  define __this_cpu_cmpxchg_1(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
 765 # endif
 766 # ifndef __this_cpu_cmpxchg_2
 767 #  define __this_cpu_cmpxchg_2(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
 768 # endif
 769 # ifndef __this_cpu_cmpxchg_4
 770 #  define __this_cpu_cmpxchg_4(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
 771 # endif
 772 # ifndef __this_cpu_cmpxchg_8
 773 #  define __this_cpu_cmpxchg_8(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
 774 # endif
 775 # define __this_cpu_cmpxchg(pcp, oval, nval)    \
 776         __pcpu_size_call_return2(__this_cpu_cmpxchg_, pcp, oval, nval)
 777 #endif
 778
 779 #define __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)       \
 780 ({                                                                      \
 781         int __ret = 0;                                                  \
 782         if (__this_cpu_read(pcp1) == (oval1) &&                         \
 783                          __this_cpu_read(pcp2)  == (oval2)) {           \
 784                 __this_cpu_write(pcp1, (nval1));                        \
 785                 __this_cpu_write(pcp2, (nval2));                        \
 786                 __ret = 1;                                              \
 787         }                                                               \
 788         (__ret);                                                        \
 789 })
 790
 791 #ifndef __this_cpu_cmpxchg_double
 792 # ifndef __this_cpu_cmpxchg_double_1
 793 #  define __this_cpu_cmpxchg_double_1(pcp1, pcp2, oval1, oval2, nval1, nval2)   \
 794         __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 795 # endif
 796 # ifndef __this_cpu_cmpxchg_double_2
 797 #  define __this_cpu_cmpxchg_double_2(pcp1, pcp2, oval1, oval2, nval1, nval2)   \
 798         __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 799 # endif
 800 # ifndef __this_cpu_cmpxchg_double_4
 801 #  define __this_cpu_cmpxchg_double_4(pcp1, pcp2, oval1, oval2, nval1, nval2)   \
 802         __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 803 # endif
 804 # ifndef __this_cpu_cmpxchg_double_8
 805 #  define __this_cpu_cmpxchg_double_8(pcp1, pcp2, oval1, oval2, nval1, nval2)   \
 806         __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 807 # endif
 808 # define __this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)      \
 809         __pcpu_double_call_return_bool(__this_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
 810 #endif
 811
 812 #endif /* __LINUX_PERCPU_H */