LXR linux/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
  81extern void *pcpu_base_addr;
  82extern const unsigned long *pcpu_unit_offsets;
  83
  84struct 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
  91struct 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
 103enum pcpu_fc {
 104        PCPU_FC_AUTO,
 105        PCPU_FC_EMBED,
 106        PCPU_FC_PAGE,
 107
 108        PCPU_FC_NR,
 109};
 110extern const char *pcpu_fc_names[PCPU_FC_NR];
 111
 112extern enum pcpu_fc pcpu_chosen_fc;
 113
 114typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
 115                                     size_t align);
 116typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
 117typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
 118typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
 119
 120extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
 121                                                             int nr_units);
 122extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
 123
 124extern 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
 128extern 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
 136extern 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
 153extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
 154extern bool is_kernel_percpu_address(unsigned long addr);
 155
 156#if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
 157extern void __init setup_per_cpu_areas(void);
 158#endif
 159extern void __init percpu_init_late(void);
 160
 161extern void __percpu *__alloc_percpu(size_t size, size_t align);
 162extern void free_percpu(void __percpu *__pdata);
 163extern 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 w.r.t. preemption.
 176 * The generic versions use plain get/put_cpu_var().  Archs are
 177 * encouraged to implement single-instruction alternatives which don't
 178 * require preemption 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)                            \
 192do {                                                                    \
 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
 227extern 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, ...)                           \
 286do {                                                                    \
 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)                           \
 349do {                                                                    \
 350        preempt_disable();                                              \
 351        *__this_cpu_ptr(&(pcp)) op val;                                 \
 352        preempt_enable();                                               \
 353} while (0)
 354
 355#ifndef this_cpu_write
 356# ifndef this_cpu_write_1
 357#  define this_cpu_write_1(pcp, val)    _this_cpu_generic_to_op((pcp), (val), =)
 358# endif
 359# ifndef this_cpu_write_2
 360#  define this_cpu_write_2(pcp, val)    _this_cpu_generic_to_op((pcp), (val), =)
 361# endif
 362# ifndef this_cpu_write_4
 363#  define this_cpu_write_4(pcp, val)    _this_cpu_generic_to_op((pcp), (val), =)
 364# endif
 365# ifndef this_cpu_write_8
 366#  define this_cpu_write_8(pcp, val)    _this_cpu_generic_to_op((pcp), (val), =)
 367# endif
 368# define this_cpu_write(pcp, val)       __pcpu_size_call(this_cpu_write_, (pcp), (val))
 369#endif
 370
 371#ifndef this_cpu_add
 372# ifndef this_cpu_add_1
 373#  define this_cpu_add_1(pcp, val)      _this_cpu_generic_to_op((pcp), (val), +=)
 374# endif
 375# ifndef this_cpu_add_2
 376#  define this_cpu_add_2(pcp, val)      _this_cpu_generic_to_op((pcp), (val), +=)
 377# endif
 378# ifndef this_cpu_add_4
 379#  define this_cpu_add_4(pcp, val)      _this_cpu_generic_to_op((pcp), (val), +=)
 380# endif
 381# ifndef this_cpu_add_8
 382#  define this_cpu_add_8(pcp, val)      _this_cpu_generic_to_op((pcp), (val), +=)
 383# endif
 384# define this_cpu_add(pcp, val)         __pcpu_size_call(this_cpu_add_, (pcp), (val))
 385#endif
 386
 387#ifndef this_cpu_sub
 388# define this_cpu_sub(pcp, val)         this_cpu_add((pcp), -(val))
 389#endif
 390
 391#ifndef this_cpu_inc
 392# define this_cpu_inc(pcp)              this_cpu_add((pcp), 1)
 393#endif
 394
 395#ifndef this_cpu_dec
 396# define this_cpu_dec(pcp)              this_cpu_sub((pcp), 1)
 397#endif
 398
 399#ifndef this_cpu_and
 400# ifndef this_cpu_and_1
 401#  define this_cpu_and_1(pcp, val)      _this_cpu_generic_to_op((pcp), (val), &=)
 402# endif
 403# ifndef this_cpu_and_2
 404#  define this_cpu_and_2(pcp, val)      _this_cpu_generic_to_op((pcp), (val), &=)
 405# endif
 406# ifndef this_cpu_and_4
 407#  define this_cpu_and_4(pcp, val)      _this_cpu_generic_to_op((pcp), (val), &=)
 408# endif
 409# ifndef this_cpu_and_8
 410#  define this_cpu_and_8(pcp, val)      _this_cpu_generic_to_op((pcp), (val), &=)
 411# endif
 412# define this_cpu_and(pcp, val)         __pcpu_size_call(this_cpu_and_, (pcp), (val))
 413#endif
 414
 415#ifndef this_cpu_or
 416# ifndef this_cpu_or_1
 417#  define this_cpu_or_1(pcp, val)       _this_cpu_generic_to_op((pcp), (val), |=)
 418# endif
 419# ifndef this_cpu_or_2
 420#  define this_cpu_or_2(pcp, val)       _this_cpu_generic_to_op((pcp), (val), |=)
 421# endif
 422# ifndef this_cpu_or_4
 423#  define this_cpu_or_4(pcp, val)       _this_cpu_generic_to_op((pcp), (val), |=)
 424# endif
 425# ifndef this_cpu_or_8
 426#  define this_cpu_or_8(pcp, val)       _this_cpu_generic_to_op((pcp), (val), |=)
 427# endif
 428# define this_cpu_or(pcp, val)          __pcpu_size_call(this_cpu_or_, (pcp), (val))
 429#endif
 430
 431#ifndef this_cpu_xor
 432# ifndef this_cpu_xor_1
 433#  define this_cpu_xor_1(pcp, val)      _this_cpu_generic_to_op((pcp), (val), ^=)
 434# endif
 435# ifndef this_cpu_xor_2
 436#  define this_cpu_xor_2(pcp, val)      _this_cpu_generic_to_op((pcp), (val), ^=)
 437# endif
 438# ifndef this_cpu_xor_4
 439#  define this_cpu_xor_4(pcp, val)      _this_cpu_generic_to_op((pcp), (val), ^=)
 440# endif
 441# ifndef this_cpu_xor_8
 442#  define this_cpu_xor_8(pcp, val)      _this_cpu_generic_to_op((pcp), (val), ^=)
 443# endif
 444# define this_cpu_xor(pcp, val)         __pcpu_size_call(this_cpu_or_, (pcp), (val))
 445#endif
 446
 447#define _this_cpu_generic_add_return(pcp, val)                          \
 448({                                                                      \
 449        typeof(pcp) ret__;                                              \
 450        preempt_disable();                                              \
 451        __this_cpu_add(pcp, val);                                       \
 452        ret__ = __this_cpu_read(pcp);                                   \
 453        preempt_enable();                                               \
 454        ret__;                                                          \
 455})
 456
 457#ifndef this_cpu_add_return
 458# ifndef this_cpu_add_return_1
 459#  define this_cpu_add_return_1(pcp, val)       _this_cpu_generic_add_return(pcp, val)
 460# endif
 461# ifndef this_cpu_add_return_2
 462#  define this_cpu_add_return_2(pcp, val)       _this_cpu_generic_add_return(pcp, val)
 463# endif
 464# ifndef this_cpu_add_return_4
 465#  define this_cpu_add_return_4(pcp, val)       _this_cpu_generic_add_return(pcp, val)
 466# endif
 467# ifndef this_cpu_add_return_8
 468#  define this_cpu_add_return_8(pcp, val)       _this_cpu_generic_add_return(pcp, val)
 469# endif
 470# define this_cpu_add_return(pcp, val)  __pcpu_size_call_return2(this_cpu_add_return_, pcp, val)
 471#endif
 472
 473#define this_cpu_sub_return(pcp, val)   this_cpu_add_return(pcp, -(val))
 474#define this_cpu_inc_return(pcp)        this_cpu_add_return(pcp, 1)
 475#define this_cpu_dec_return(pcp)        this_cpu_add_return(pcp, -1)
 476
 477#define _this_cpu_generic_xchg(pcp, nval)                               \
 478({      typeof(pcp) ret__;                                              \
 479        preempt_disable();                                              \
 480        ret__ = __this_cpu_read(pcp);                                   \
 481        __this_cpu_write(pcp, nval);                                    \
 482        preempt_enable();                                               \
 483        ret__;                                                          \
 484})
 485
 486#ifndef this_cpu_xchg
 487# ifndef this_cpu_xchg_1
 488#  define this_cpu_xchg_1(pcp, nval)    _this_cpu_generic_xchg(pcp, nval)
 489# endif
 490# ifndef this_cpu_xchg_2
 491#  define this_cpu_xchg_2(pcp, nval)    _this_cpu_generic_xchg(pcp, nval)
 492# endif
 493# ifndef this_cpu_xchg_4
 494#  define this_cpu_xchg_4(pcp, nval)    _this_cpu_generic_xchg(pcp, nval)
 495# endif
 496# ifndef this_cpu_xchg_8
 497#  define this_cpu_xchg_8(pcp, nval)    _this_cpu_generic_xchg(pcp, nval)
 498# endif
 499# define this_cpu_xchg(pcp, nval)       \
 500        __pcpu_size_call_return2(this_cpu_xchg_, (pcp), nval)
 501#endif
 502
 503#define _this_cpu_generic_cmpxchg(pcp, oval, nval)                      \
 504({      typeof(pcp) ret__;                                              \
 505        preempt_disable();                                              \
 506        ret__ = __this_cpu_read(pcp);                                   \
 507        if (ret__ == (oval))                                            \
 508                __this_cpu_write(pcp, nval);                            \
 509        preempt_enable();                                               \
 510        ret__;                                                          \
 511})
 512
 513#ifndef this_cpu_cmpxchg
 514# ifndef this_cpu_cmpxchg_1
 515#  define this_cpu_cmpxchg_1(pcp, oval, nval)   _this_cpu_generic_cmpxchg(pcp, oval, nval)
 516# endif
 517# ifndef this_cpu_cmpxchg_2
 518#  define this_cpu_cmpxchg_2(pcp, oval, nval)   _this_cpu_generic_cmpxchg(pcp, oval, nval)
 519# endif
 520# ifndef this_cpu_cmpxchg_4
 521#  define this_cpu_cmpxchg_4(pcp, oval, nval)   _this_cpu_generic_cmpxchg(pcp, oval, nval)
 522# endif
 523# ifndef this_cpu_cmpxchg_8
 524#  define this_cpu_cmpxchg_8(pcp, oval, nval)   _this_cpu_generic_cmpxchg(pcp, oval, nval)
 525# endif
 526# define this_cpu_cmpxchg(pcp, oval, nval)      \
 527        __pcpu_size_call_return2(this_cpu_cmpxchg_, pcp, oval, nval)
 528#endif
 529
 530/*
 531 * cmpxchg_double replaces two adjacent scalars at once.  The first
 532 * two parameters are per cpu variables which have to be of the same
 533 * size.  A truth value is returned to indicate success or failure
 534 * (since a double register result is difficult to handle).  There is
 535 * very limited hardware support for these operations, so only certain
 536 * sizes may work.
 537 */
 538#define _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)        \
 539({                                                                      \
 540        int ret__;                                                      \
 541        preempt_disable();                                              \
 542        ret__ = __this_cpu_generic_cmpxchg_double(pcp1, pcp2,           \
 543                        oval1, oval2, nval1, nval2);                    \
 544        preempt_enable();                                               \
 545        ret__;                                                          \
 546})
 547
 548#ifndef this_cpu_cmpxchg_double
 549# ifndef this_cpu_cmpxchg_double_1
 550#  define this_cpu_cmpxchg_double_1(pcp1, pcp2, oval1, oval2, nval1, nval2)     \
 551        _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 552# endif
 553# ifndef this_cpu_cmpxchg_double_2
 554#  define this_cpu_cmpxchg_double_2(pcp1, pcp2, oval1, oval2, nval1, nval2)     \
 555        _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 556# endif
 557# ifndef this_cpu_cmpxchg_double_4
 558#  define this_cpu_cmpxchg_double_4(pcp1, pcp2, oval1, oval2, nval1, nval2)     \
 559        _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 560# endif
 561# ifndef this_cpu_cmpxchg_double_8
 562#  define this_cpu_cmpxchg_double_8(pcp1, pcp2, oval1, oval2, nval1, nval2)     \
 563        _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 564# endif
 565# define this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)        \
 566        __pcpu_double_call_return_bool(this_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
 567#endif
 568
 569/*
 570 * Generic percpu operations that do not require preemption handling.
 571 * Either we do not care about races or the caller has the
 572 * responsibility of handling preemptions issues. Arch code can still
 573 * override these instructions since the arch per cpu code may be more
 574 * efficient and may actually get race freeness for free (that is the
 575 * case for x86 for example).
 576 *
 577 * If there is no other protection through preempt disable and/or
 578 * disabling interupts then one of these RMW operations can show unexpected
 579 * behavior because the execution thread was rescheduled on another processor
 580 * or an interrupt occurred and the same percpu variable was modified from
 581 * the interrupt context.
 582 */
 583#ifndef __this_cpu_read
 584# ifndef __this_cpu_read_1
 585#  define __this_cpu_read_1(pcp)        (*__this_cpu_ptr(&(pcp)))
 586# endif
 587# ifndef __this_cpu_read_2
 588#  define __this_cpu_read_2(pcp)        (*__this_cpu_ptr(&(pcp)))
 589# endif
 590# ifndef __this_cpu_read_4
 591#  define __this_cpu_read_4(pcp)        (*__this_cpu_ptr(&(pcp)))
 592# endif
 593# ifndef __this_cpu_read_8
 594#  define __this_cpu_read_8(pcp)        (*__this_cpu_ptr(&(pcp)))
 595# endif
 596# define __this_cpu_read(pcp)   __pcpu_size_call_return(__this_cpu_read_, (pcp))
 597#endif
 598
 599#define __this_cpu_generic_to_op(pcp, val, op)                          \
 600do {                                                                    \
 601        *__this_cpu_ptr(&(pcp)) op val;                                 \
 602} while (0)
 603
 604#ifndef __this_cpu_write
 605# ifndef __this_cpu_write_1
 606#  define __this_cpu_write_1(pcp, val)  __this_cpu_generic_to_op((pcp), (val), =)
 607# endif
 608# ifndef __this_cpu_write_2
 609#  define __this_cpu_write_2(pcp, val)  __this_cpu_generic_to_op((pcp), (val), =)
 610# endif
 611# ifndef __this_cpu_write_4
 612#  define __this_cpu_write_4(pcp, val)  __this_cpu_generic_to_op((pcp), (val), =)
 613# endif
 614# ifndef __this_cpu_write_8
 615#  define __this_cpu_write_8(pcp, val)  __this_cpu_generic_to_op((pcp), (val), =)
 616# endif
 617# define __this_cpu_write(pcp, val)     __pcpu_size_call(__this_cpu_write_, (pcp), (val))
 618#endif
 619
 620#ifndef __this_cpu_add
 621# ifndef __this_cpu_add_1
 622#  define __this_cpu_add_1(pcp, val)    __this_cpu_generic_to_op((pcp), (val), +=)
 623# endif
 624# ifndef __this_cpu_add_2
 625#  define __this_cpu_add_2(pcp, val)    __this_cpu_generic_to_op((pcp), (val), +=)
 626# endif
 627# ifndef __this_cpu_add_4
 628#  define __this_cpu_add_4(pcp, val)    __this_cpu_generic_to_op((pcp), (val), +=)
 629# endif
 630# ifndef __this_cpu_add_8
 631#  define __this_cpu_add_8(pcp, val)    __this_cpu_generic_to_op((pcp), (val), +=)
 632# endif
 633# define __this_cpu_add(pcp, val)       __pcpu_size_call(__this_cpu_add_, (pcp), (val))
 634#endif
 635
 636#ifndef __this_cpu_sub
 637# define __this_cpu_sub(pcp, val)       __this_cpu_add((pcp), -(val))
 638#endif
 639
 640#ifndef __this_cpu_inc
 641# define __this_cpu_inc(pcp)            __this_cpu_add((pcp), 1)
 642#endif
 643
 644#ifndef __this_cpu_dec
 645# define __this_cpu_dec(pcp)            __this_cpu_sub((pcp), 1)
 646#endif
 647
 648#ifndef __this_cpu_and
 649# ifndef __this_cpu_and_1
 650#  define __this_cpu_and_1(pcp, val)    __this_cpu_generic_to_op((pcp), (val), &=)
 651# endif
 652# ifndef __this_cpu_and_2
 653#  define __this_cpu_and_2(pcp, val)    __this_cpu_generic_to_op((pcp), (val), &=)
 654# endif
 655# ifndef __this_cpu_and_4
 656#  define __this_cpu_and_4(pcp, val)    __this_cpu_generic_to_op((pcp), (val), &=)
 657# endif
 658# ifndef __this_cpu_and_8
 659#  define __this_cpu_and_8(pcp, val)    __this_cpu_generic_to_op((pcp), (val), &=)
 660# endif
 661# define __this_cpu_and(pcp, val)       __pcpu_size_call(__this_cpu_and_, (pcp), (val))
 662#endif
 663
 664#ifndef __this_cpu_or
 665# ifndef __this_cpu_or_1
 666#  define __this_cpu_or_1(pcp, val)     __this_cpu_generic_to_op((pcp), (val), |=)
 667# endif
 668# ifndef __this_cpu_or_2
 669#  define __this_cpu_or_2(pcp, val)     __this_cpu_generic_to_op((pcp), (val), |=)
 670# endif
 671# ifndef __this_cpu_or_4
 672#  define __this_cpu_or_4(pcp, val)     __this_cpu_generic_to_op((pcp), (val), |=)
 673# endif
 674# ifndef __this_cpu_or_8
 675#  define __this_cpu_or_8(pcp, val)     __this_cpu_generic_to_op((pcp), (val), |=)
 676# endif
 677# define __this_cpu_or(pcp, val)        __pcpu_size_call(__this_cpu_or_, (pcp), (val))
 678#endif
 679
 680#ifndef __this_cpu_xor
 681# ifndef __this_cpu_xor_1
 682#  define __this_cpu_xor_1(pcp, val)    __this_cpu_generic_to_op((pcp), (val), ^=)
 683# endif
 684# ifndef __this_cpu_xor_2
 685#  define __this_cpu_xor_2(pcp, val)    __this_cpu_generic_to_op((pcp), (val), ^=)
 686# endif
 687# ifndef __this_cpu_xor_4
 688#  define __this_cpu_xor_4(pcp, val)    __this_cpu_generic_to_op((pcp), (val), ^=)
 689# endif
 690# ifndef __this_cpu_xor_8
 691#  define __this_cpu_xor_8(pcp, val)    __this_cpu_generic_to_op((pcp), (val), ^=)
 692# endif
 693# define __this_cpu_xor(pcp, val)       __pcpu_size_call(__this_cpu_xor_, (pcp), (val))
 694#endif
 695
 696#define __this_cpu_generic_add_return(pcp, val)                         \
 697({                                                                      \
 698        __this_cpu_add(pcp, val);                                       \
 699        __this_cpu_read(pcp);                                           \
 700})
 701
 702#ifndef __this_cpu_add_return
 703# ifndef __this_cpu_add_return_1
 704#  define __this_cpu_add_return_1(pcp, val)     __this_cpu_generic_add_return(pcp, val)
 705# endif
 706# ifndef __this_cpu_add_return_2
 707#  define __this_cpu_add_return_2(pcp, val)     __this_cpu_generic_add_return(pcp, val)
 708# endif
 709# ifndef __this_cpu_add_return_4
 710#  define __this_cpu_add_return_4(pcp, val)     __this_cpu_generic_add_return(pcp, val)
 711# endif
 712# ifndef __this_cpu_add_return_8
 713#  define __this_cpu_add_return_8(pcp, val)     __this_cpu_generic_add_return(pcp, val)
 714# endif
 715# define __this_cpu_add_return(pcp, val)        __pcpu_size_call_return2(this_cpu_add_return_, pcp, val)
 716#endif
 717
 718#define __this_cpu_sub_return(pcp, val) this_cpu_add_return(pcp, -(val))
 719#define __this_cpu_inc_return(pcp)      this_cpu_add_return(pcp, 1)
 720#define __this_cpu_dec_return(pcp)      this_cpu_add_return(pcp, -1)
 721
 722#define __this_cpu_generic_xchg(pcp, nval)                              \
 723({      typeof(pcp) ret__;                                              \
 724        ret__ = __this_cpu_read(pcp);                                   \
 725        __this_cpu_write(pcp, nval);                                    \
 726        ret__;                                                          \
 727})
 728
 729#ifndef __this_cpu_xchg
 730# ifndef __this_cpu_xchg_1
 731#  define __this_cpu_xchg_1(pcp, nval)  __this_cpu_generic_xchg(pcp, nval)
 732# endif
 733# ifndef __this_cpu_xchg_2
 734#  define __this_cpu_xchg_2(pcp, nval)  __this_cpu_generic_xchg(pcp, nval)
 735# endif
 736# ifndef __this_cpu_xchg_4
 737#  define __this_cpu_xchg_4(pcp, nval)  __this_cpu_generic_xchg(pcp, nval)
 738# endif
 739# ifndef __this_cpu_xchg_8
 740#  define __this_cpu_xchg_8(pcp, nval)  __this_cpu_generic_xchg(pcp, nval)
 741# endif
 742# define __this_cpu_xchg(pcp, nval)     \
 743        __pcpu_size_call_return2(__this_cpu_xchg_, (pcp), nval)
 744#endif
 745
 746#define __this_cpu_generic_cmpxchg(pcp, oval, nval)                     \
 747({                                                                      \
 748        typeof(pcp) ret__;                                              \
 749        ret__ = __this_cpu_read(pcp);                                   \
 750        if (ret__ == (oval))                                            \
 751                __this_cpu_write(pcp, nval);                            \
 752        ret__;                                                          \
 753})
 754
 755#ifndef __this_cpu_cmpxchg
 756# ifndef __this_cpu_cmpxchg_1
 757#  define __this_cpu_cmpxchg_1(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
 758# endif
 759# ifndef __this_cpu_cmpxchg_2
 760#  define __this_cpu_cmpxchg_2(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
 761# endif
 762# ifndef __this_cpu_cmpxchg_4
 763#  define __this_cpu_cmpxchg_4(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
 764# endif
 765# ifndef __this_cpu_cmpxchg_8
 766#  define __this_cpu_cmpxchg_8(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
 767# endif
 768# define __this_cpu_cmpxchg(pcp, oval, nval)    \
 769        __pcpu_size_call_return2(__this_cpu_cmpxchg_, pcp, oval, nval)
 770#endif
 771
 772#define __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)       \
 773({                                                                      \
 774        int __ret = 0;                                                  \
 775        if (__this_cpu_read(pcp1) == (oval1) &&                         \
 776                         __this_cpu_read(pcp2)  == (oval2)) {           \
 777                __this_cpu_write(pcp1, (nval1));                        \
 778                __this_cpu_write(pcp2, (nval2));                        \
 779                __ret = 1;                                              \
 780        }                                                               \
 781        (__ret);                                                        \
 782})
 783
 784#ifndef __this_cpu_cmpxchg_double
 785# ifndef __this_cpu_cmpxchg_double_1
 786#  define __this_cpu_cmpxchg_double_1(pcp1, pcp2, oval1, oval2, nval1, nval2)   \
 787        __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 788# endif
 789# ifndef __this_cpu_cmpxchg_double_2
 790#  define __this_cpu_cmpxchg_double_2(pcp1, pcp2, oval1, oval2, nval1, nval2)   \
 791        __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 792# endif
 793# ifndef __this_cpu_cmpxchg_double_4
 794#  define __this_cpu_cmpxchg_double_4(pcp1, pcp2, oval1, oval2, nval1, nval2)   \
 795        __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 796# endif
 797# ifndef __this_cpu_cmpxchg_double_8
 798#  define __this_cpu_cmpxchg_double_8(pcp1, pcp2, oval1, oval2, nval1, nval2)   \
 799        __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 800# endif
 801# define __this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)      \
 802        __pcpu_double_call_return_bool(__this_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
 803#endif
 804
 805/*
 806 * IRQ safe versions of the per cpu RMW operations. Note that these operations
 807 * are *not* safe against modification of the same variable from another
 808 * processors (which one gets when using regular atomic operations)
 809 * They are guaranteed to be atomic vs. local interrupts and
 810 * preemption only.
 811 */
 812#define irqsafe_cpu_generic_to_op(pcp, val, op)                         \
 813do {                                                                    \
 814        unsigned long flags;                                            \
 815        local_irq_save(flags);                                          \
 816        *__this_cpu_ptr(&(pcp)) op val;                                 \
 817        local_irq_restore(flags);                                       \
 818} while (0)
 819
 820#ifndef irqsafe_cpu_add
 821# ifndef irqsafe_cpu_add_1
 822#  define irqsafe_cpu_add_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
 823# endif
 824# ifndef irqsafe_cpu_add_2
 825#  define irqsafe_cpu_add_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
 826# endif
 827# ifndef irqsafe_cpu_add_4
 828#  define irqsafe_cpu_add_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
 829# endif
 830# ifndef irqsafe_cpu_add_8
 831#  define irqsafe_cpu_add_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
 832# endif
 833# define irqsafe_cpu_add(pcp, val) __pcpu_size_call(irqsafe_cpu_add_, (pcp), (val))
 834#endif
 835
 836#ifndef irqsafe_cpu_sub
 837# define irqsafe_cpu_sub(pcp, val)      irqsafe_cpu_add((pcp), -(val))
 838#endif
 839
 840#ifndef irqsafe_cpu_inc
 841# define irqsafe_cpu_inc(pcp)   irqsafe_cpu_add((pcp), 1)
 842#endif
 843
 844#ifndef irqsafe_cpu_dec
 845# define irqsafe_cpu_dec(pcp)   irqsafe_cpu_sub((pcp), 1)
 846#endif
 847
 848#ifndef irqsafe_cpu_and
 849# ifndef irqsafe_cpu_and_1
 850#  define irqsafe_cpu_and_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
 851# endif
 852# ifndef irqsafe_cpu_and_2
 853#  define irqsafe_cpu_and_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
 854# endif
 855# ifndef irqsafe_cpu_and_4
 856#  define irqsafe_cpu_and_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
 857# endif
 858# ifndef irqsafe_cpu_and_8
 859#  define irqsafe_cpu_and_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
 860# endif
 861# define irqsafe_cpu_and(pcp, val) __pcpu_size_call(irqsafe_cpu_and_, (val))
 862#endif
 863
 864#ifndef irqsafe_cpu_or
 865# ifndef irqsafe_cpu_or_1
 866#  define irqsafe_cpu_or_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
 867# endif
 868# ifndef irqsafe_cpu_or_2
 869#  define irqsafe_cpu_or_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
 870# endif
 871# ifndef irqsafe_cpu_or_4
 872#  define irqsafe_cpu_or_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
 873# endif
 874# ifndef irqsafe_cpu_or_8
 875#  define irqsafe_cpu_or_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
 876# endif
 877# define irqsafe_cpu_or(pcp, val) __pcpu_size_call(irqsafe_cpu_or_, (val))
 878#endif
 879
 880#ifndef irqsafe_cpu_xor
 881# ifndef irqsafe_cpu_xor_1
 882#  define irqsafe_cpu_xor_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
 883# endif
 884# ifndef irqsafe_cpu_xor_2
 885#  define irqsafe_cpu_xor_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
 886# endif
 887# ifndef irqsafe_cpu_xor_4
 888#  define irqsafe_cpu_xor_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
 889# endif
 890# ifndef irqsafe_cpu_xor_8
 891#  define irqsafe_cpu_xor_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
 892# endif
 893# define irqsafe_cpu_xor(pcp, val) __pcpu_size_call(irqsafe_cpu_xor_, (val))
 894#endif
 895
 896#define irqsafe_cpu_generic_cmpxchg(pcp, oval, nval)                    \
 897({                                                                      \
 898        typeof(pcp) ret__;                                              \
 899        unsigned long flags;                                            \
 900        local_irq_save(flags);                                          \
 901        ret__ = __this_cpu_read(pcp);                                   \
 902        if (ret__ == (oval))                                            \
 903                __this_cpu_write(pcp, nval);                            \
 904        local_irq_restore(flags);                                       \
 905        ret__;                                                          \
 906})
 907
 908#ifndef irqsafe_cpu_cmpxchg
 909# ifndef irqsafe_cpu_cmpxchg_1
 910#  define irqsafe_cpu_cmpxchg_1(pcp, oval, nval)        irqsafe_cpu_generic_cmpxchg(pcp, oval, nval)
 911# endif
 912# ifndef irqsafe_cpu_cmpxchg_2
 913#  define irqsafe_cpu_cmpxchg_2(pcp, oval, nval)        irqsafe_cpu_generic_cmpxchg(pcp, oval, nval)
 914# endif
 915# ifndef irqsafe_cpu_cmpxchg_4
 916#  define irqsafe_cpu_cmpxchg_4(pcp, oval, nval)        irqsafe_cpu_generic_cmpxchg(pcp, oval, nval)
 917# endif
 918# ifndef irqsafe_cpu_cmpxchg_8
 919#  define irqsafe_cpu_cmpxchg_8(pcp, oval, nval)        irqsafe_cpu_generic_cmpxchg(pcp, oval, nval)
 920# endif
 921# define irqsafe_cpu_cmpxchg(pcp, oval, nval)           \
 922        __pcpu_size_call_return2(irqsafe_cpu_cmpxchg_, (pcp), oval, nval)
 923#endif
 924
 925#define irqsafe_generic_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)      \
 926({                                                                      \
 927        int ret__;                                                      \
 928        unsigned long flags;                                            \
 929        local_irq_save(flags);                                          \
 930        ret__ = __this_cpu_generic_cmpxchg_double(pcp1, pcp2,           \
 931                        oval1, oval2, nval1, nval2);                    \
 932        local_irq_restore(flags);                                       \
 933        ret__;                                                          \
 934})
 935
 936#ifndef irqsafe_cpu_cmpxchg_double
 937# ifndef irqsafe_cpu_cmpxchg_double_1
 938#  define irqsafe_cpu_cmpxchg_double_1(pcp1, pcp2, oval1, oval2, nval1, nval2)  \
 939        irqsafe_generic_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 940# endif
 941# ifndef irqsafe_cpu_cmpxchg_double_2
 942#  define irqsafe_cpu_cmpxchg_double_2(pcp1, pcp2, oval1, oval2, nval1, nval2)  \
 943        irqsafe_generic_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 944# endif
 945# ifndef irqsafe_cpu_cmpxchg_double_4
 946#  define irqsafe_cpu_cmpxchg_double_4(pcp1, pcp2, oval1, oval2, nval1, nval2)  \
 947        irqsafe_generic_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 948# endif
 949# ifndef irqsafe_cpu_cmpxchg_double_8
 950#  define irqsafe_cpu_cmpxchg_double_8(pcp1, pcp2, oval1, oval2, nval1, nval2)  \
 951        irqsafe_generic_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 952# endif
 953# define irqsafe_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)     \
 954        __pcpu_double_call_return_bool(irqsafe_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
 955#endif
 956
 957#endif /* __LINUX_PERCPU_H */
 958