Linux kernel mirror (for testing)
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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 */