include/linux/percpu.h

   1 #ifndef __LINUX_PERCPU_H
   2 #define __LINUX_PERCPU_H
   3
   4 #include <linux/preempt.h>
   5 #include <linux/slab.h> /* For kmalloc() */
   6 #include <linux/smp.h>
   7 #include <linux/cpumask.h>
   8 #include <linux/pfn.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         extern int simple_identifier_##var(void);       \
  31         preempt_disable();                              \
  32         &__get_cpu_var(var); }))
  33 #define put_cpu_var(var) preempt_enable()
  34
  35 #ifdef CONFIG_SMP
  36
  37 /* minimum unit size, also is the maximum supported allocation size */
  38 #define PCPU_MIN_UNIT_SIZE              PFN_ALIGN(64 << 10)
  39
  40 /*
  41  * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy
  42  * back on the first chunk for dynamic percpu allocation if arch is
  43  * manually allocating and mapping it for faster access (as a part of
  44  * large page mapping for example).
  45  *
  46  * The following values give between one and two pages of free space
  47  * after typical minimal boot (2-way SMP, single disk and NIC) with
  48  * both defconfig and a distro config on x86_64 and 32.  More
  49  * intelligent way to determine this would be nice.
  50  */
  51 #if BITS_PER_LONG > 32
  52 #define PERCPU_DYNAMIC_RESERVE          (20 << 10)
  53 #else
  54 #define PERCPU_DYNAMIC_RESERVE          (12 << 10)
  55 #endif
  56
  57 extern void *pcpu_base_addr;
  58 extern const unsigned long *pcpu_unit_offsets;
  59
  60 struct pcpu_group_info {
  61         int                     nr_units;       /* aligned # of units */
  62         unsigned long           base_offset;    /* base address offset */
  63         unsigned int            *cpu_map;       /* unit->cpu map, empty
  64                                                  * entries contain NR_CPUS */
  65 };
  66
  67 struct pcpu_alloc_info {
  68         size_t                  static_size;
  69         size_t                  reserved_size;
  70         size_t                  dyn_size;
  71         size_t                  unit_size;
  72         size_t                  atom_size;
  73         size_t                  alloc_size;
  74         size_t                  __ai_size;      /* internal, don't use */
  75         int                     nr_groups;      /* 0 if grouping unnecessary */
  76         struct pcpu_group_info  groups[];
  77 };
  78
  79 enum pcpu_fc {
  80         PCPU_FC_AUTO,
  81         PCPU_FC_EMBED,
  82         PCPU_FC_PAGE,
  83
  84         PCPU_FC_NR,
  85 };
  86 extern const char *pcpu_fc_names[PCPU_FC_NR];
  87
  88 extern enum pcpu_fc pcpu_chosen_fc;
  89
  90 typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
  91                                      size_t align);
  92 typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
  93 typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
  94 typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
  95
  96 extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
  97                                                              int nr_units);
  98 extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
  99
 100 extern struct pcpu_alloc_info * __init pcpu_build_alloc_info(
 101                                 size_t reserved_size, ssize_t dyn_size,
 102                                 size_t atom_size,
 103                                 pcpu_fc_cpu_distance_fn_t cpu_distance_fn);
 104
 105 extern int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
 106                                          void *base_addr);
 107
 108 #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
 109 extern int __init pcpu_embed_first_chunk(size_t reserved_size, ssize_t dyn_size,
 110                                 size_t atom_size,
 111                                 pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
 112                                 pcpu_fc_alloc_fn_t alloc_fn,
 113                                 pcpu_fc_free_fn_t free_fn);
 114 #endif
 115
 116 #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
 117 extern int __init pcpu_page_first_chunk(size_t reserved_size,
 118                                 pcpu_fc_alloc_fn_t alloc_fn,
 119                                 pcpu_fc_free_fn_t free_fn,
 120                                 pcpu_fc_populate_pte_fn_t populate_pte_fn);
 121 #endif
 122
 123 /*
 124  * Use this to get to a cpu's version of the per-cpu object
 125  * dynamically allocated. Non-atomic access to the current CPU's
 126  * version should probably be combined with get_cpu()/put_cpu().
 127  */
 128 #define per_cpu_ptr(ptr, cpu)   SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu)))
 129
 130 extern void *__alloc_reserved_percpu(size_t size, size_t align);
 131 extern void *__alloc_percpu(size_t size, size_t align);
 132 extern void free_percpu(void *__pdata);
 133
 134 #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
 135 extern void __init setup_per_cpu_areas(void);
 136 #endif
 137
 138 #else /* CONFIG_SMP */
 139
 140 #define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
 141
 142 static inline void *__alloc_percpu(size_t size, size_t align)
 143 {
 144         /*
 145          * Can't easily make larger alignment work with kmalloc.  WARN
 146          * on it.  Larger alignment should only be used for module
 147          * percpu sections on SMP for which this path isn't used.
 148          */
 149         WARN_ON_ONCE(align > SMP_CACHE_BYTES);
 150         return kzalloc(size, GFP_KERNEL);
 151 }
 152
 153 static inline void free_percpu(void *p)
 154 {
 155         kfree(p);
 156 }
 157
 158 static inline void __init setup_per_cpu_areas(void) { }
 159
 160 static inline void *pcpu_lpage_remapped(void *kaddr)
 161 {
 162         return NULL;
 163 }
 164
 165 #endif /* CONFIG_SMP */
 166
 167 #define alloc_percpu(type)      \
 168         (typeof(type) *)__alloc_percpu(sizeof(type), __alignof__(type))
 169
 170 /*
 171  * Optional methods for optimized non-lvalue per-cpu variable access.
 172  *
 173  * @var can be a percpu variable or a field of it and its size should
 174  * equal char, int or long.  percpu_read() evaluates to a lvalue and
 175  * all others to void.
 176  *
 177  * These operations are guaranteed to be atomic w.r.t. preemption.
 178  * The generic versions use plain get/put_cpu_var().  Archs are
 179  * encouraged to implement single-instruction alternatives which don't
 180  * require preemption protection.
 181  */
 182 #ifndef percpu_read
 183 # define percpu_read(var)                                               \
 184   ({                                                                    \
 185         typeof(var) __tmp_var__;                                        \
 186         __tmp_var__ = get_cpu_var(var);                                 \
 187         put_cpu_var(var);                                               \
 188         __tmp_var__;                                                    \
 189   })
 190 #endif
 191
 192 #define __percpu_generic_to_op(var, val, op)                            \
 193 do {                                                                    \
 194         get_cpu_var(var) op val;                                        \
 195         put_cpu_var(var);                                               \
 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         switch(sizeof(variable)) {                                      \
 232         case 1: pscr_ret__ = stem##1(variable);break;                   \
 233         case 2: pscr_ret__ = stem##2(variable);break;                   \
 234         case 4: pscr_ret__ = stem##4(variable);break;                   \
 235         case 8: pscr_ret__ = stem##8(variable);break;                   \
 236         default:                                                        \
 237                 __bad_size_call_parameter();break;                      \
 238         }                                                               \
 239         pscr_ret__;                                                     \
 240 })
 241
 242 #define __pcpu_size_call(stem, variable, ...)                           \
 243 do {                                                                    \
 244         switch(sizeof(variable)) {                                      \
 245                 case 1: stem##1(variable, __VA_ARGS__);break;           \
 246                 case 2: stem##2(variable, __VA_ARGS__);break;           \
 247                 case 4: stem##4(variable, __VA_ARGS__);break;           \
 248                 case 8: stem##8(variable, __VA_ARGS__);break;           \
 249                 default:                                                \
 250                         __bad_size_call_parameter();break;              \
 251         }                                                               \
 252 } while (0)
 253
 254 /*
 255  * Optimized manipulation for memory allocated through the per cpu
 256  * allocator or for addresses of per cpu variables.
 257  *
 258  * These operation guarantee exclusivity of access for other operations
 259  * on the *same* processor. The assumption is that per cpu data is only
 260  * accessed by a single processor instance (the current one).
 261  *
 262  * The first group is used for accesses that must be done in a
 263  * preemption safe way since we know that the context is not preempt
 264  * safe. Interrupts may occur. If the interrupt modifies the variable
 265  * too then RMW actions will not be reliable.
 266  *
 267  * The arch code can provide optimized functions in two ways:
 268  *
 269  * 1. Override the function completely. F.e. define this_cpu_add().
 270  *    The arch must then ensure that the various scalar format passed
 271  *    are handled correctly.
 272  *
 273  * 2. Provide functions for certain scalar sizes. F.e. provide
 274  *    this_cpu_add_2() to provide per cpu atomic operations for 2 byte
 275  *    sized RMW actions. If arch code does not provide operations for
 276  *    a scalar size then the fallback in the generic code will be
 277  *    used.
 278  */
 279
 280 #define _this_cpu_generic_read(pcp)                                     \
 281 ({      typeof(pcp) ret__;                                              \
 282         preempt_disable();                                              \
 283         ret__ = *this_cpu_ptr(&(pcp));                                  \
 284         preempt_enable();                                               \
 285         ret__;                                                          \
 286 })
 287
 288 #ifndef this_cpu_read
 289 # ifndef this_cpu_read_1
 290 #  define this_cpu_read_1(pcp)  _this_cpu_generic_read(pcp)
 291 # endif
 292 # ifndef this_cpu_read_2
 293 #  define this_cpu_read_2(pcp)  _this_cpu_generic_read(pcp)
 294 # endif
 295 # ifndef this_cpu_read_4
 296 #  define this_cpu_read_4(pcp)  _this_cpu_generic_read(pcp)
 297 # endif
 298 # ifndef this_cpu_read_8
 299 #  define this_cpu_read_8(pcp)  _this_cpu_generic_read(pcp)
 300 # endif
 301 # define this_cpu_read(pcp)     __pcpu_size_call_return(this_cpu_read_, (pcp))
 302 #endif
 303
 304 #define _this_cpu_generic_to_op(pcp, val, op)                           \
 305 do {                                                                    \
 306         preempt_disable();                                              \
 307         *__this_cpu_ptr(&pcp) op val;                                   \
 308         preempt_enable();                                               \
 309 } while (0)
 310
 311 #ifndef this_cpu_write
 312 # ifndef this_cpu_write_1
 313 #  define this_cpu_write_1(pcp, val)    _this_cpu_generic_to_op((pcp), (val), =)
 314 # endif
 315 # ifndef this_cpu_write_2
 316 #  define this_cpu_write_2(pcp, val)    _this_cpu_generic_to_op((pcp), (val), =)
 317 # endif
 318 # ifndef this_cpu_write_4
 319 #  define this_cpu_write_4(pcp, val)    _this_cpu_generic_to_op((pcp), (val), =)
 320 # endif
 321 # ifndef this_cpu_write_8
 322 #  define this_cpu_write_8(pcp, val)    _this_cpu_generic_to_op((pcp), (val), =)
 323 # endif
 324 # define this_cpu_write(pcp, val)       __pcpu_size_call(this_cpu_write_, (pcp), (val))
 325 #endif
 326
 327 #ifndef this_cpu_add
 328 # ifndef this_cpu_add_1
 329 #  define this_cpu_add_1(pcp, val)      _this_cpu_generic_to_op((pcp), (val), +=)
 330 # endif
 331 # ifndef this_cpu_add_2
 332 #  define this_cpu_add_2(pcp, val)      _this_cpu_generic_to_op((pcp), (val), +=)
 333 # endif
 334 # ifndef this_cpu_add_4
 335 #  define this_cpu_add_4(pcp, val)      _this_cpu_generic_to_op((pcp), (val), +=)
 336 # endif
 337 # ifndef this_cpu_add_8
 338 #  define this_cpu_add_8(pcp, val)      _this_cpu_generic_to_op((pcp), (val), +=)
 339 # endif
 340 # define this_cpu_add(pcp, val)         __pcpu_size_call(this_cpu_add_, (pcp), (val))
 341 #endif
 342
 343 #ifndef this_cpu_sub
 344 # define this_cpu_sub(pcp, val)         this_cpu_add((pcp), -(val))
 345 #endif
 346
 347 #ifndef this_cpu_inc
 348 # define this_cpu_inc(pcp)              this_cpu_add((pcp), 1)
 349 #endif
 350
 351 #ifndef this_cpu_dec
 352 # define this_cpu_dec(pcp)              this_cpu_sub((pcp), 1)
 353 #endif
 354
 355 #ifndef this_cpu_and
 356 # ifndef this_cpu_and_1
 357 #  define this_cpu_and_1(pcp, val)      _this_cpu_generic_to_op((pcp), (val), &=)
 358 # endif
 359 # ifndef this_cpu_and_2
 360 #  define this_cpu_and_2(pcp, val)      _this_cpu_generic_to_op((pcp), (val), &=)
 361 # endif
 362 # ifndef this_cpu_and_4
 363 #  define this_cpu_and_4(pcp, val)      _this_cpu_generic_to_op((pcp), (val), &=)
 364 # endif
 365 # ifndef this_cpu_and_8
 366 #  define this_cpu_and_8(pcp, val)      _this_cpu_generic_to_op((pcp), (val), &=)
 367 # endif
 368 # define this_cpu_and(pcp, val)         __pcpu_size_call(this_cpu_and_, (pcp), (val))
 369 #endif
 370
 371 #ifndef this_cpu_or
 372 # ifndef this_cpu_or_1
 373 #  define this_cpu_or_1(pcp, val)       _this_cpu_generic_to_op((pcp), (val), |=)
 374 # endif
 375 # ifndef this_cpu_or_2
 376 #  define this_cpu_or_2(pcp, val)       _this_cpu_generic_to_op((pcp), (val), |=)
 377 # endif
 378 # ifndef this_cpu_or_4
 379 #  define this_cpu_or_4(pcp, val)       _this_cpu_generic_to_op((pcp), (val), |=)
 380 # endif
 381 # ifndef this_cpu_or_8
 382 #  define this_cpu_or_8(pcp, val)       _this_cpu_generic_to_op((pcp), (val), |=)
 383 # endif
 384 # define this_cpu_or(pcp, val)          __pcpu_size_call(this_cpu_or_, (pcp), (val))
 385 #endif
 386
 387 #ifndef this_cpu_xor
 388 # ifndef this_cpu_xor_1
 389 #  define this_cpu_xor_1(pcp, val)      _this_cpu_generic_to_op((pcp), (val), ^=)
 390 # endif
 391 # ifndef this_cpu_xor_2
 392 #  define this_cpu_xor_2(pcp, val)      _this_cpu_generic_to_op((pcp), (val), ^=)
 393 # endif
 394 # ifndef this_cpu_xor_4
 395 #  define this_cpu_xor_4(pcp, val)      _this_cpu_generic_to_op((pcp), (val), ^=)
 396 # endif
 397 # ifndef this_cpu_xor_8
 398 #  define this_cpu_xor_8(pcp, val)      _this_cpu_generic_to_op((pcp), (val), ^=)
 399 # endif
 400 # define this_cpu_xor(pcp, val)         __pcpu_size_call(this_cpu_or_, (pcp), (val))
 401 #endif
 402
 403 /*
 404  * Generic percpu operations that do not require preemption handling.
 405  * Either we do not care about races or the caller has the
 406  * responsibility of handling preemptions issues. Arch code can still
 407  * override these instructions since the arch per cpu code may be more
 408  * efficient and may actually get race freeness for free (that is the
 409  * case for x86 for example).
 410  *
 411  * If there is no other protection through preempt disable and/or
 412  * disabling interupts then one of these RMW operations can show unexpected
 413  * behavior because the execution thread was rescheduled on another processor
 414  * or an interrupt occurred and the same percpu variable was modified from
 415  * the interrupt context.
 416  */
 417 #ifndef __this_cpu_read
 418 # ifndef __this_cpu_read_1
 419 #  define __this_cpu_read_1(pcp)        (*__this_cpu_ptr(&(pcp)))
 420 # endif
 421 # ifndef __this_cpu_read_2
 422 #  define __this_cpu_read_2(pcp)        (*__this_cpu_ptr(&(pcp)))
 423 # endif
 424 # ifndef __this_cpu_read_4
 425 #  define __this_cpu_read_4(pcp)        (*__this_cpu_ptr(&(pcp)))
 426 # endif
 427 # ifndef __this_cpu_read_8
 428 #  define __this_cpu_read_8(pcp)        (*__this_cpu_ptr(&(pcp)))
 429 # endif
 430 # define __this_cpu_read(pcp)   __pcpu_size_call_return(__this_cpu_read_, (pcp))
 431 #endif
 432
 433 #define __this_cpu_generic_to_op(pcp, val, op)                          \
 434 do {                                                                    \
 435         *__this_cpu_ptr(&(pcp)) op val;                                 \
 436 } while (0)
 437
 438 #ifndef __this_cpu_write
 439 # ifndef __this_cpu_write_1
 440 #  define __this_cpu_write_1(pcp, val)  __this_cpu_generic_to_op((pcp), (val), =)
 441 # endif
 442 # ifndef __this_cpu_write_2
 443 #  define __this_cpu_write_2(pcp, val)  __this_cpu_generic_to_op((pcp), (val), =)
 444 # endif
 445 # ifndef __this_cpu_write_4
 446 #  define __this_cpu_write_4(pcp, val)  __this_cpu_generic_to_op((pcp), (val), =)
 447 # endif
 448 # ifndef __this_cpu_write_8
 449 #  define __this_cpu_write_8(pcp, val)  __this_cpu_generic_to_op((pcp), (val), =)
 450 # endif
 451 # define __this_cpu_write(pcp, val)     __pcpu_size_call(__this_cpu_write_, (pcp), (val))
 452 #endif
 453
 454 #ifndef __this_cpu_add
 455 # ifndef __this_cpu_add_1
 456 #  define __this_cpu_add_1(pcp, val)    __this_cpu_generic_to_op((pcp), (val), +=)
 457 # endif
 458 # ifndef __this_cpu_add_2
 459 #  define __this_cpu_add_2(pcp, val)    __this_cpu_generic_to_op((pcp), (val), +=)
 460 # endif
 461 # ifndef __this_cpu_add_4
 462 #  define __this_cpu_add_4(pcp, val)    __this_cpu_generic_to_op((pcp), (val), +=)
 463 # endif
 464 # ifndef __this_cpu_add_8
 465 #  define __this_cpu_add_8(pcp, val)    __this_cpu_generic_to_op((pcp), (val), +=)
 466 # endif
 467 # define __this_cpu_add(pcp, val)       __pcpu_size_call(__this_cpu_add_, (pcp), (val))
 468 #endif
 469
 470 #ifndef __this_cpu_sub
 471 # define __this_cpu_sub(pcp, val)       __this_cpu_add((pcp), -(val))
 472 #endif
 473
 474 #ifndef __this_cpu_inc
 475 # define __this_cpu_inc(pcp)            __this_cpu_add((pcp), 1)
 476 #endif
 477
 478 #ifndef __this_cpu_dec
 479 # define __this_cpu_dec(pcp)            __this_cpu_sub((pcp), 1)
 480 #endif
 481
 482 #ifndef __this_cpu_and
 483 # ifndef __this_cpu_and_1
 484 #  define __this_cpu_and_1(pcp, val)    __this_cpu_generic_to_op((pcp), (val), &=)
 485 # endif
 486 # ifndef __this_cpu_and_2
 487 #  define __this_cpu_and_2(pcp, val)    __this_cpu_generic_to_op((pcp), (val), &=)
 488 # endif
 489 # ifndef __this_cpu_and_4
 490 #  define __this_cpu_and_4(pcp, val)    __this_cpu_generic_to_op((pcp), (val), &=)
 491 # endif
 492 # ifndef __this_cpu_and_8
 493 #  define __this_cpu_and_8(pcp, val)    __this_cpu_generic_to_op((pcp), (val), &=)
 494 # endif
 495 # define __this_cpu_and(pcp, val)       __pcpu_size_call(__this_cpu_and_, (pcp), (val))
 496 #endif
 497
 498 #ifndef __this_cpu_or
 499 # ifndef __this_cpu_or_1
 500 #  define __this_cpu_or_1(pcp, val)     __this_cpu_generic_to_op((pcp), (val), |=)
 501 # endif
 502 # ifndef __this_cpu_or_2
 503 #  define __this_cpu_or_2(pcp, val)     __this_cpu_generic_to_op((pcp), (val), |=)
 504 # endif
 505 # ifndef __this_cpu_or_4
 506 #  define __this_cpu_or_4(pcp, val)     __this_cpu_generic_to_op((pcp), (val), |=)
 507 # endif
 508 # ifndef __this_cpu_or_8
 509 #  define __this_cpu_or_8(pcp, val)     __this_cpu_generic_to_op((pcp), (val), |=)
 510 # endif
 511 # define __this_cpu_or(pcp, val)        __pcpu_size_call(__this_cpu_or_, (pcp), (val))
 512 #endif
 513
 514 #ifndef __this_cpu_xor
 515 # ifndef __this_cpu_xor_1
 516 #  define __this_cpu_xor_1(pcp, val)    __this_cpu_generic_to_op((pcp), (val), ^=)
 517 # endif
 518 # ifndef __this_cpu_xor_2
 519 #  define __this_cpu_xor_2(pcp, val)    __this_cpu_generic_to_op((pcp), (val), ^=)
 520 # endif
 521 # ifndef __this_cpu_xor_4
 522 #  define __this_cpu_xor_4(pcp, val)    __this_cpu_generic_to_op((pcp), (val), ^=)
 523 # endif
 524 # ifndef __this_cpu_xor_8
 525 #  define __this_cpu_xor_8(pcp, val)    __this_cpu_generic_to_op((pcp), (val), ^=)
 526 # endif
 527 # define __this_cpu_xor(pcp, val)       __pcpu_size_call(__this_cpu_xor_, (pcp), (val))
 528 #endif
 529
 530 /*
 531  * IRQ safe versions of the per cpu RMW operations. Note that these operations
 532  * are *not* safe against modification of the same variable from another
 533  * processors (which one gets when using regular atomic operations)
 534  . They are guaranteed to be atomic vs. local interrupts and
 535  * preemption only.
 536  */
 537 #define irqsafe_cpu_generic_to_op(pcp, val, op)                         \
 538 do {                                                                    \
 539         unsigned long flags;                                            \
 540         local_irq_save(flags);                                          \
 541         *__this_cpu_ptr(&(pcp)) op val;                                 \
 542         local_irq_restore(flags);                                       \
 543 } while (0)
 544
 545 #ifndef irqsafe_cpu_add
 546 # ifndef irqsafe_cpu_add_1
 547 #  define irqsafe_cpu_add_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
 548 # endif
 549 # ifndef irqsafe_cpu_add_2
 550 #  define irqsafe_cpu_add_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
 551 # endif
 552 # ifndef irqsafe_cpu_add_4
 553 #  define irqsafe_cpu_add_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
 554 # endif
 555 # ifndef irqsafe_cpu_add_8
 556 #  define irqsafe_cpu_add_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
 557 # endif
 558 # define irqsafe_cpu_add(pcp, val) __pcpu_size_call(irqsafe_cpu_add_, (pcp), (val))
 559 #endif
 560
 561 #ifndef irqsafe_cpu_sub
 562 # define irqsafe_cpu_sub(pcp, val)      irqsafe_cpu_add((pcp), -(val))
 563 #endif
 564
 565 #ifndef irqsafe_cpu_inc
 566 # define irqsafe_cpu_inc(pcp)   irqsafe_cpu_add((pcp), 1)
 567 #endif
 568
 569 #ifndef irqsafe_cpu_dec
 570 # define irqsafe_cpu_dec(pcp)   irqsafe_cpu_sub((pcp), 1)
 571 #endif
 572
 573 #ifndef irqsafe_cpu_and
 574 # ifndef irqsafe_cpu_and_1
 575 #  define irqsafe_cpu_and_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
 576 # endif
 577 # ifndef irqsafe_cpu_and_2
 578 #  define irqsafe_cpu_and_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
 579 # endif
 580 # ifndef irqsafe_cpu_and_4
 581 #  define irqsafe_cpu_and_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
 582 # endif
 583 # ifndef irqsafe_cpu_and_8
 584 #  define irqsafe_cpu_and_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
 585 # endif
 586 # define irqsafe_cpu_and(pcp, val) __pcpu_size_call(irqsafe_cpu_and_, (val))
 587 #endif
 588
 589 #ifndef irqsafe_cpu_or
 590 # ifndef irqsafe_cpu_or_1
 591 #  define irqsafe_cpu_or_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
 592 # endif
 593 # ifndef irqsafe_cpu_or_2
 594 #  define irqsafe_cpu_or_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
 595 # endif
 596 # ifndef irqsafe_cpu_or_4
 597 #  define irqsafe_cpu_or_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
 598 # endif
 599 # ifndef irqsafe_cpu_or_8
 600 #  define irqsafe_cpu_or_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
 601 # endif
 602 # define irqsafe_cpu_or(pcp, val) __pcpu_size_call(irqsafe_cpu_or_, (val))
 603 #endif
 604
 605 #ifndef irqsafe_cpu_xor
 606 # ifndef irqsafe_cpu_xor_1
 607 #  define irqsafe_cpu_xor_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
 608 # endif
 609 # ifndef irqsafe_cpu_xor_2
 610 #  define irqsafe_cpu_xor_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
 611 # endif
 612 # ifndef irqsafe_cpu_xor_4
 613 #  define irqsafe_cpu_xor_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
 614 # endif
 615 # ifndef irqsafe_cpu_xor_8
 616 #  define irqsafe_cpu_xor_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
 617 # endif
 618 # define irqsafe_cpu_xor(pcp, val) __pcpu_size_call(irqsafe_cpu_xor_, (val))
 619 #endif
 620
 621 #endif /* __LINUX_PERCPU_H */