Linux kernel mirror (for testing)
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linux
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 */
263#define __pcpu_double_call_return_bool(stem, pcp1, pcp2, ...) \
264({ \
265 bool pdcrb_ret__; \
266 __verify_pcpu_ptr(&pcp1); \
267 BUILD_BUG_ON(sizeof(pcp1) != sizeof(pcp2)); \
268 VM_BUG_ON((unsigned long)(&pcp1) % (2 * sizeof(pcp1))); \
269 VM_BUG_ON((unsigned long)(&pcp2) != \
270 (unsigned long)(&pcp1) + sizeof(pcp1)); \
271 switch(sizeof(pcp1)) { \
272 case 1: pdcrb_ret__ = stem##1(pcp1, pcp2, __VA_ARGS__); break; \
273 case 2: pdcrb_ret__ = stem##2(pcp1, pcp2, __VA_ARGS__); break; \
274 case 4: pdcrb_ret__ = stem##4(pcp1, pcp2, __VA_ARGS__); break; \
275 case 8: pdcrb_ret__ = stem##8(pcp1, pcp2, __VA_ARGS__); break; \
276 default: \
277 __bad_size_call_parameter(); break; \
278 } \
279 pdcrb_ret__; \
280})
281
282#define __pcpu_size_call(stem, variable, ...) \
283do { \
284 __verify_pcpu_ptr(&(variable)); \
285 switch(sizeof(variable)) { \
286 case 1: stem##1(variable, __VA_ARGS__);break; \
287 case 2: stem##2(variable, __VA_ARGS__);break; \
288 case 4: stem##4(variable, __VA_ARGS__);break; \
289 case 8: stem##8(variable, __VA_ARGS__);break; \
290 default: \
291 __bad_size_call_parameter();break; \
292 } \
293} while (0)
294
295/*
296 * Optimized manipulation for memory allocated through the per cpu
297 * allocator or for addresses of per cpu variables.
298 *
299 * These operation guarantee exclusivity of access for other operations
300 * on the *same* processor. The assumption is that per cpu data is only
301 * accessed by a single processor instance (the current one).
302 *
303 * The first group is used for accesses that must be done in a
304 * preemption safe way since we know that the context is not preempt
305 * safe. Interrupts may occur. If the interrupt modifies the variable
306 * too then RMW actions will not be reliable.
307 *
308 * The arch code can provide optimized functions in two ways:
309 *
310 * 1. Override the function completely. F.e. define this_cpu_add().
311 * The arch must then ensure that the various scalar format passed
312 * are handled correctly.
313 *
314 * 2. Provide functions for certain scalar sizes. F.e. provide
315 * this_cpu_add_2() to provide per cpu atomic operations for 2 byte
316 * sized RMW actions. If arch code does not provide operations for
317 * a scalar size then the fallback in the generic code will be
318 * used.
319 */
320
321#define _this_cpu_generic_read(pcp) \
322({ typeof(pcp) ret__; \
323 preempt_disable(); \
324 ret__ = *this_cpu_ptr(&(pcp)); \
325 preempt_enable(); \
326 ret__; \
327})
328
329#ifndef this_cpu_read
330# ifndef this_cpu_read_1
331# define this_cpu_read_1(pcp) _this_cpu_generic_read(pcp)
332# endif
333# ifndef this_cpu_read_2
334# define this_cpu_read_2(pcp) _this_cpu_generic_read(pcp)
335# endif
336# ifndef this_cpu_read_4
337# define this_cpu_read_4(pcp) _this_cpu_generic_read(pcp)
338# endif
339# ifndef this_cpu_read_8
340# define this_cpu_read_8(pcp) _this_cpu_generic_read(pcp)
341# endif
342# define this_cpu_read(pcp) __pcpu_size_call_return(this_cpu_read_, (pcp))
343#endif
344
345#define _this_cpu_generic_to_op(pcp, val, op) \
346do { \
347 preempt_disable(); \
348 *__this_cpu_ptr(&(pcp)) op val; \
349 preempt_enable(); \
350} while (0)
351
352#ifndef this_cpu_write
353# ifndef this_cpu_write_1
354# define this_cpu_write_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), =)
355# endif
356# ifndef this_cpu_write_2
357# define this_cpu_write_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), =)
358# endif
359# ifndef this_cpu_write_4
360# define this_cpu_write_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), =)
361# endif
362# ifndef this_cpu_write_8
363# define this_cpu_write_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), =)
364# endif
365# define this_cpu_write(pcp, val) __pcpu_size_call(this_cpu_write_, (pcp), (val))
366#endif
367
368#ifndef this_cpu_add
369# ifndef this_cpu_add_1
370# define this_cpu_add_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=)
371# endif
372# ifndef this_cpu_add_2
373# define this_cpu_add_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=)
374# endif
375# ifndef this_cpu_add_4
376# define this_cpu_add_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=)
377# endif
378# ifndef this_cpu_add_8
379# define this_cpu_add_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=)
380# endif
381# define this_cpu_add(pcp, val) __pcpu_size_call(this_cpu_add_, (pcp), (val))
382#endif
383
384#ifndef this_cpu_sub
385# define this_cpu_sub(pcp, val) this_cpu_add((pcp), -(val))
386#endif
387
388#ifndef this_cpu_inc
389# define this_cpu_inc(pcp) this_cpu_add((pcp), 1)
390#endif
391
392#ifndef this_cpu_dec
393# define this_cpu_dec(pcp) this_cpu_sub((pcp), 1)
394#endif
395
396#ifndef this_cpu_and
397# ifndef this_cpu_and_1
398# define this_cpu_and_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=)
399# endif
400# ifndef this_cpu_and_2
401# define this_cpu_and_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=)
402# endif
403# ifndef this_cpu_and_4
404# define this_cpu_and_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=)
405# endif
406# ifndef this_cpu_and_8
407# define this_cpu_and_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=)
408# endif
409# define this_cpu_and(pcp, val) __pcpu_size_call(this_cpu_and_, (pcp), (val))
410#endif
411
412#ifndef this_cpu_or
413# ifndef this_cpu_or_1
414# define this_cpu_or_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=)
415# endif
416# ifndef this_cpu_or_2
417# define this_cpu_or_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=)
418# endif
419# ifndef this_cpu_or_4
420# define this_cpu_or_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=)
421# endif
422# ifndef this_cpu_or_8
423# define this_cpu_or_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=)
424# endif
425# define this_cpu_or(pcp, val) __pcpu_size_call(this_cpu_or_, (pcp), (val))
426#endif
427
428#ifndef this_cpu_xor
429# ifndef this_cpu_xor_1
430# define this_cpu_xor_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=)
431# endif
432# ifndef this_cpu_xor_2
433# define this_cpu_xor_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=)
434# endif
435# ifndef this_cpu_xor_4
436# define this_cpu_xor_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=)
437# endif
438# ifndef this_cpu_xor_8
439# define this_cpu_xor_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=)
440# endif
441# define this_cpu_xor(pcp, val) __pcpu_size_call(this_cpu_or_, (pcp), (val))
442#endif
443
444#define _this_cpu_generic_add_return(pcp, val) \
445({ \
446 typeof(pcp) ret__; \
447 preempt_disable(); \
448 __this_cpu_add(pcp, val); \
449 ret__ = __this_cpu_read(pcp); \
450 preempt_enable(); \
451 ret__; \
452})
453
454#ifndef this_cpu_add_return
455# ifndef this_cpu_add_return_1
456# define this_cpu_add_return_1(pcp, val) _this_cpu_generic_add_return(pcp, val)
457# endif
458# ifndef this_cpu_add_return_2
459# define this_cpu_add_return_2(pcp, val) _this_cpu_generic_add_return(pcp, val)
460# endif
461# ifndef this_cpu_add_return_4
462# define this_cpu_add_return_4(pcp, val) _this_cpu_generic_add_return(pcp, val)
463# endif
464# ifndef this_cpu_add_return_8
465# define this_cpu_add_return_8(pcp, val) _this_cpu_generic_add_return(pcp, val)
466# endif
467# define this_cpu_add_return(pcp, val) __pcpu_size_call_return2(this_cpu_add_return_, pcp, val)
468#endif
469
470#define this_cpu_sub_return(pcp, val) this_cpu_add_return(pcp, -(val))
471#define this_cpu_inc_return(pcp) this_cpu_add_return(pcp, 1)
472#define this_cpu_dec_return(pcp) this_cpu_add_return(pcp, -1)
473
474#define _this_cpu_generic_xchg(pcp, nval) \
475({ typeof(pcp) ret__; \
476 preempt_disable(); \
477 ret__ = __this_cpu_read(pcp); \
478 __this_cpu_write(pcp, nval); \
479 preempt_enable(); \
480 ret__; \
481})
482
483#ifndef this_cpu_xchg
484# ifndef this_cpu_xchg_1
485# define this_cpu_xchg_1(pcp, nval) _this_cpu_generic_xchg(pcp, nval)
486# endif
487# ifndef this_cpu_xchg_2
488# define this_cpu_xchg_2(pcp, nval) _this_cpu_generic_xchg(pcp, nval)
489# endif
490# ifndef this_cpu_xchg_4
491# define this_cpu_xchg_4(pcp, nval) _this_cpu_generic_xchg(pcp, nval)
492# endif
493# ifndef this_cpu_xchg_8
494# define this_cpu_xchg_8(pcp, nval) _this_cpu_generic_xchg(pcp, nval)
495# endif
496# define this_cpu_xchg(pcp, nval) \
497 __pcpu_size_call_return2(this_cpu_xchg_, (pcp), nval)
498#endif
499
500#define _this_cpu_generic_cmpxchg(pcp, oval, nval) \
501({ typeof(pcp) ret__; \
502 preempt_disable(); \
503 ret__ = __this_cpu_read(pcp); \
504 if (ret__ == (oval)) \
505 __this_cpu_write(pcp, nval); \
506 preempt_enable(); \
507 ret__; \
508})
509
510#ifndef this_cpu_cmpxchg
511# ifndef this_cpu_cmpxchg_1
512# define this_cpu_cmpxchg_1(pcp, oval, nval) _this_cpu_generic_cmpxchg(pcp, oval, nval)
513# endif
514# ifndef this_cpu_cmpxchg_2
515# define this_cpu_cmpxchg_2(pcp, oval, nval) _this_cpu_generic_cmpxchg(pcp, oval, nval)
516# endif
517# ifndef this_cpu_cmpxchg_4
518# define this_cpu_cmpxchg_4(pcp, oval, nval) _this_cpu_generic_cmpxchg(pcp, oval, nval)
519# endif
520# ifndef this_cpu_cmpxchg_8
521# define this_cpu_cmpxchg_8(pcp, oval, nval) _this_cpu_generic_cmpxchg(pcp, oval, nval)
522# endif
523# define this_cpu_cmpxchg(pcp, oval, nval) \
524 __pcpu_size_call_return2(this_cpu_cmpxchg_, pcp, oval, nval)
525#endif
526
527/*
528 * cmpxchg_double replaces two adjacent scalars at once. The first
529 * two parameters are per cpu variables which have to be of the same
530 * size. A truth value is returned to indicate success or failure
531 * (since a double register result is difficult to handle). There is
532 * very limited hardware support for these operations, so only certain
533 * sizes may work.
534 */
535#define _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
536({ \
537 int ret__; \
538 preempt_disable(); \
539 ret__ = __this_cpu_generic_cmpxchg_double(pcp1, pcp2, \
540 oval1, oval2, nval1, nval2); \
541 preempt_enable(); \
542 ret__; \
543})
544
545#ifndef this_cpu_cmpxchg_double
546# ifndef this_cpu_cmpxchg_double_1
547# define this_cpu_cmpxchg_double_1(pcp1, pcp2, oval1, oval2, nval1, nval2) \
548 _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
549# endif
550# ifndef this_cpu_cmpxchg_double_2
551# define this_cpu_cmpxchg_double_2(pcp1, pcp2, oval1, oval2, nval1, nval2) \
552 _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
553# endif
554# ifndef this_cpu_cmpxchg_double_4
555# define this_cpu_cmpxchg_double_4(pcp1, pcp2, oval1, oval2, nval1, nval2) \
556 _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
557# endif
558# ifndef this_cpu_cmpxchg_double_8
559# define this_cpu_cmpxchg_double_8(pcp1, pcp2, oval1, oval2, nval1, nval2) \
560 _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
561# endif
562# define this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
563 __pcpu_double_call_return_bool(this_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
564#endif
565
566/*
567 * Generic percpu operations that do not require preemption handling.
568 * Either we do not care about races or the caller has the
569 * responsibility of handling preemptions issues. Arch code can still
570 * override these instructions since the arch per cpu code may be more
571 * efficient and may actually get race freeness for free (that is the
572 * case for x86 for example).
573 *
574 * If there is no other protection through preempt disable and/or
575 * disabling interupts then one of these RMW operations can show unexpected
576 * behavior because the execution thread was rescheduled on another processor
577 * or an interrupt occurred and the same percpu variable was modified from
578 * the interrupt context.
579 */
580#ifndef __this_cpu_read
581# ifndef __this_cpu_read_1
582# define __this_cpu_read_1(pcp) (*__this_cpu_ptr(&(pcp)))
583# endif
584# ifndef __this_cpu_read_2
585# define __this_cpu_read_2(pcp) (*__this_cpu_ptr(&(pcp)))
586# endif
587# ifndef __this_cpu_read_4
588# define __this_cpu_read_4(pcp) (*__this_cpu_ptr(&(pcp)))
589# endif
590# ifndef __this_cpu_read_8
591# define __this_cpu_read_8(pcp) (*__this_cpu_ptr(&(pcp)))
592# endif
593# define __this_cpu_read(pcp) __pcpu_size_call_return(__this_cpu_read_, (pcp))
594#endif
595
596#define __this_cpu_generic_to_op(pcp, val, op) \
597do { \
598 *__this_cpu_ptr(&(pcp)) op val; \
599} while (0)
600
601#ifndef __this_cpu_write
602# ifndef __this_cpu_write_1
603# define __this_cpu_write_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), =)
604# endif
605# ifndef __this_cpu_write_2
606# define __this_cpu_write_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), =)
607# endif
608# ifndef __this_cpu_write_4
609# define __this_cpu_write_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), =)
610# endif
611# ifndef __this_cpu_write_8
612# define __this_cpu_write_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), =)
613# endif
614# define __this_cpu_write(pcp, val) __pcpu_size_call(__this_cpu_write_, (pcp), (val))
615#endif
616
617#ifndef __this_cpu_add
618# ifndef __this_cpu_add_1
619# define __this_cpu_add_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=)
620# endif
621# ifndef __this_cpu_add_2
622# define __this_cpu_add_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=)
623# endif
624# ifndef __this_cpu_add_4
625# define __this_cpu_add_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=)
626# endif
627# ifndef __this_cpu_add_8
628# define __this_cpu_add_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=)
629# endif
630# define __this_cpu_add(pcp, val) __pcpu_size_call(__this_cpu_add_, (pcp), (val))
631#endif
632
633#ifndef __this_cpu_sub
634# define __this_cpu_sub(pcp, val) __this_cpu_add((pcp), -(val))
635#endif
636
637#ifndef __this_cpu_inc
638# define __this_cpu_inc(pcp) __this_cpu_add((pcp), 1)
639#endif
640
641#ifndef __this_cpu_dec
642# define __this_cpu_dec(pcp) __this_cpu_sub((pcp), 1)
643#endif
644
645#ifndef __this_cpu_and
646# ifndef __this_cpu_and_1
647# define __this_cpu_and_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=)
648# endif
649# ifndef __this_cpu_and_2
650# define __this_cpu_and_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=)
651# endif
652# ifndef __this_cpu_and_4
653# define __this_cpu_and_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=)
654# endif
655# ifndef __this_cpu_and_8
656# define __this_cpu_and_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=)
657# endif
658# define __this_cpu_and(pcp, val) __pcpu_size_call(__this_cpu_and_, (pcp), (val))
659#endif
660
661#ifndef __this_cpu_or
662# ifndef __this_cpu_or_1
663# define __this_cpu_or_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=)
664# endif
665# ifndef __this_cpu_or_2
666# define __this_cpu_or_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=)
667# endif
668# ifndef __this_cpu_or_4
669# define __this_cpu_or_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=)
670# endif
671# ifndef __this_cpu_or_8
672# define __this_cpu_or_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=)
673# endif
674# define __this_cpu_or(pcp, val) __pcpu_size_call(__this_cpu_or_, (pcp), (val))
675#endif
676
677#ifndef __this_cpu_xor
678# ifndef __this_cpu_xor_1
679# define __this_cpu_xor_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=)
680# endif
681# ifndef __this_cpu_xor_2
682# define __this_cpu_xor_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=)
683# endif
684# ifndef __this_cpu_xor_4
685# define __this_cpu_xor_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=)
686# endif
687# ifndef __this_cpu_xor_8
688# define __this_cpu_xor_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=)
689# endif
690# define __this_cpu_xor(pcp, val) __pcpu_size_call(__this_cpu_xor_, (pcp), (val))
691#endif
692
693#define __this_cpu_generic_add_return(pcp, val) \
694({ \
695 __this_cpu_add(pcp, val); \
696 __this_cpu_read(pcp); \
697})
698
699#ifndef __this_cpu_add_return
700# ifndef __this_cpu_add_return_1
701# define __this_cpu_add_return_1(pcp, val) __this_cpu_generic_add_return(pcp, val)
702# endif
703# ifndef __this_cpu_add_return_2
704# define __this_cpu_add_return_2(pcp, val) __this_cpu_generic_add_return(pcp, val)
705# endif
706# ifndef __this_cpu_add_return_4
707# define __this_cpu_add_return_4(pcp, val) __this_cpu_generic_add_return(pcp, val)
708# endif
709# ifndef __this_cpu_add_return_8
710# define __this_cpu_add_return_8(pcp, val) __this_cpu_generic_add_return(pcp, val)
711# endif
712# define __this_cpu_add_return(pcp, val) __pcpu_size_call_return2(this_cpu_add_return_, pcp, val)
713#endif
714
715#define __this_cpu_sub_return(pcp, val) this_cpu_add_return(pcp, -(val))
716#define __this_cpu_inc_return(pcp) this_cpu_add_return(pcp, 1)
717#define __this_cpu_dec_return(pcp) this_cpu_add_return(pcp, -1)
718
719#define __this_cpu_generic_xchg(pcp, nval) \
720({ typeof(pcp) ret__; \
721 ret__ = __this_cpu_read(pcp); \
722 __this_cpu_write(pcp, nval); \
723 ret__; \
724})
725
726#ifndef __this_cpu_xchg
727# ifndef __this_cpu_xchg_1
728# define __this_cpu_xchg_1(pcp, nval) __this_cpu_generic_xchg(pcp, nval)
729# endif
730# ifndef __this_cpu_xchg_2
731# define __this_cpu_xchg_2(pcp, nval) __this_cpu_generic_xchg(pcp, nval)
732# endif
733# ifndef __this_cpu_xchg_4
734# define __this_cpu_xchg_4(pcp, nval) __this_cpu_generic_xchg(pcp, nval)
735# endif
736# ifndef __this_cpu_xchg_8
737# define __this_cpu_xchg_8(pcp, nval) __this_cpu_generic_xchg(pcp, nval)
738# endif
739# define __this_cpu_xchg(pcp, nval) \
740 __pcpu_size_call_return2(__this_cpu_xchg_, (pcp), nval)
741#endif
742
743#define __this_cpu_generic_cmpxchg(pcp, oval, nval) \
744({ \
745 typeof(pcp) ret__; \
746 ret__ = __this_cpu_read(pcp); \
747 if (ret__ == (oval)) \
748 __this_cpu_write(pcp, nval); \
749 ret__; \
750})
751
752#ifndef __this_cpu_cmpxchg
753# ifndef __this_cpu_cmpxchg_1
754# define __this_cpu_cmpxchg_1(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
755# endif
756# ifndef __this_cpu_cmpxchg_2
757# define __this_cpu_cmpxchg_2(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
758# endif
759# ifndef __this_cpu_cmpxchg_4
760# define __this_cpu_cmpxchg_4(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
761# endif
762# ifndef __this_cpu_cmpxchg_8
763# define __this_cpu_cmpxchg_8(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
764# endif
765# define __this_cpu_cmpxchg(pcp, oval, nval) \
766 __pcpu_size_call_return2(__this_cpu_cmpxchg_, pcp, oval, nval)
767#endif
768
769#define __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
770({ \
771 int __ret = 0; \
772 if (__this_cpu_read(pcp1) == (oval1) && \
773 __this_cpu_read(pcp2) == (oval2)) { \
774 __this_cpu_write(pcp1, (nval1)); \
775 __this_cpu_write(pcp2, (nval2)); \
776 __ret = 1; \
777 } \
778 (__ret); \
779})
780
781#ifndef __this_cpu_cmpxchg_double
782# ifndef __this_cpu_cmpxchg_double_1
783# define __this_cpu_cmpxchg_double_1(pcp1, pcp2, oval1, oval2, nval1, nval2) \
784 __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
785# endif
786# ifndef __this_cpu_cmpxchg_double_2
787# define __this_cpu_cmpxchg_double_2(pcp1, pcp2, oval1, oval2, nval1, nval2) \
788 __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
789# endif
790# ifndef __this_cpu_cmpxchg_double_4
791# define __this_cpu_cmpxchg_double_4(pcp1, pcp2, oval1, oval2, nval1, nval2) \
792 __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
793# endif
794# ifndef __this_cpu_cmpxchg_double_8
795# define __this_cpu_cmpxchg_double_8(pcp1, pcp2, oval1, oval2, nval1, nval2) \
796 __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
797# endif
798# define __this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
799 __pcpu_double_call_return_bool(__this_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
800#endif
801
802/*
803 * IRQ safe versions of the per cpu RMW operations. Note that these operations
804 * are *not* safe against modification of the same variable from another
805 * processors (which one gets when using regular atomic operations)
806 * They are guaranteed to be atomic vs. local interrupts and
807 * preemption only.
808 */
809#define irqsafe_cpu_generic_to_op(pcp, val, op) \
810do { \
811 unsigned long flags; \
812 local_irq_save(flags); \
813 *__this_cpu_ptr(&(pcp)) op val; \
814 local_irq_restore(flags); \
815} while (0)
816
817#ifndef irqsafe_cpu_add
818# ifndef irqsafe_cpu_add_1
819# define irqsafe_cpu_add_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
820# endif
821# ifndef irqsafe_cpu_add_2
822# define irqsafe_cpu_add_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
823# endif
824# ifndef irqsafe_cpu_add_4
825# define irqsafe_cpu_add_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
826# endif
827# ifndef irqsafe_cpu_add_8
828# define irqsafe_cpu_add_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
829# endif
830# define irqsafe_cpu_add(pcp, val) __pcpu_size_call(irqsafe_cpu_add_, (pcp), (val))
831#endif
832
833#ifndef irqsafe_cpu_sub
834# define irqsafe_cpu_sub(pcp, val) irqsafe_cpu_add((pcp), -(val))
835#endif
836
837#ifndef irqsafe_cpu_inc
838# define irqsafe_cpu_inc(pcp) irqsafe_cpu_add((pcp), 1)
839#endif
840
841#ifndef irqsafe_cpu_dec
842# define irqsafe_cpu_dec(pcp) irqsafe_cpu_sub((pcp), 1)
843#endif
844
845#ifndef irqsafe_cpu_and
846# ifndef irqsafe_cpu_and_1
847# define irqsafe_cpu_and_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
848# endif
849# ifndef irqsafe_cpu_and_2
850# define irqsafe_cpu_and_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
851# endif
852# ifndef irqsafe_cpu_and_4
853# define irqsafe_cpu_and_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
854# endif
855# ifndef irqsafe_cpu_and_8
856# define irqsafe_cpu_and_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
857# endif
858# define irqsafe_cpu_and(pcp, val) __pcpu_size_call(irqsafe_cpu_and_, (val))
859#endif
860
861#ifndef irqsafe_cpu_or
862# ifndef irqsafe_cpu_or_1
863# define irqsafe_cpu_or_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
864# endif
865# ifndef irqsafe_cpu_or_2
866# define irqsafe_cpu_or_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
867# endif
868# ifndef irqsafe_cpu_or_4
869# define irqsafe_cpu_or_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
870# endif
871# ifndef irqsafe_cpu_or_8
872# define irqsafe_cpu_or_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
873# endif
874# define irqsafe_cpu_or(pcp, val) __pcpu_size_call(irqsafe_cpu_or_, (val))
875#endif
876
877#ifndef irqsafe_cpu_xor
878# ifndef irqsafe_cpu_xor_1
879# define irqsafe_cpu_xor_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
880# endif
881# ifndef irqsafe_cpu_xor_2
882# define irqsafe_cpu_xor_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
883# endif
884# ifndef irqsafe_cpu_xor_4
885# define irqsafe_cpu_xor_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
886# endif
887# ifndef irqsafe_cpu_xor_8
888# define irqsafe_cpu_xor_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
889# endif
890# define irqsafe_cpu_xor(pcp, val) __pcpu_size_call(irqsafe_cpu_xor_, (val))
891#endif
892
893#define irqsafe_cpu_generic_cmpxchg(pcp, oval, nval) \
894({ \
895 typeof(pcp) ret__; \
896 unsigned long flags; \
897 local_irq_save(flags); \
898 ret__ = __this_cpu_read(pcp); \
899 if (ret__ == (oval)) \
900 __this_cpu_write(pcp, nval); \
901 local_irq_restore(flags); \
902 ret__; \
903})
904
905#ifndef irqsafe_cpu_cmpxchg
906# ifndef irqsafe_cpu_cmpxchg_1
907# define irqsafe_cpu_cmpxchg_1(pcp, oval, nval) irqsafe_cpu_generic_cmpxchg(pcp, oval, nval)
908# endif
909# ifndef irqsafe_cpu_cmpxchg_2
910# define irqsafe_cpu_cmpxchg_2(pcp, oval, nval) irqsafe_cpu_generic_cmpxchg(pcp, oval, nval)
911# endif
912# ifndef irqsafe_cpu_cmpxchg_4
913# define irqsafe_cpu_cmpxchg_4(pcp, oval, nval) irqsafe_cpu_generic_cmpxchg(pcp, oval, nval)
914# endif
915# ifndef irqsafe_cpu_cmpxchg_8
916# define irqsafe_cpu_cmpxchg_8(pcp, oval, nval) irqsafe_cpu_generic_cmpxchg(pcp, oval, nval)
917# endif
918# define irqsafe_cpu_cmpxchg(pcp, oval, nval) \
919 __pcpu_size_call_return2(irqsafe_cpu_cmpxchg_, (pcp), oval, nval)
920#endif
921
922#define irqsafe_generic_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
923({ \
924 int ret__; \
925 unsigned long flags; \
926 local_irq_save(flags); \
927 ret__ = __this_cpu_generic_cmpxchg_double(pcp1, pcp2, \
928 oval1, oval2, nval1, nval2); \
929 local_irq_restore(flags); \
930 ret__; \
931})
932
933#ifndef irqsafe_cpu_cmpxchg_double
934# ifndef irqsafe_cpu_cmpxchg_double_1
935# define irqsafe_cpu_cmpxchg_double_1(pcp1, pcp2, oval1, oval2, nval1, nval2) \
936 irqsafe_generic_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
937# endif
938# ifndef irqsafe_cpu_cmpxchg_double_2
939# define irqsafe_cpu_cmpxchg_double_2(pcp1, pcp2, oval1, oval2, nval1, nval2) \
940 irqsafe_generic_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
941# endif
942# ifndef irqsafe_cpu_cmpxchg_double_4
943# define irqsafe_cpu_cmpxchg_double_4(pcp1, pcp2, oval1, oval2, nval1, nval2) \
944 irqsafe_generic_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
945# endif
946# ifndef irqsafe_cpu_cmpxchg_double_8
947# define irqsafe_cpu_cmpxchg_double_8(pcp1, pcp2, oval1, oval2, nval1, nval2) \
948 irqsafe_generic_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
949# endif
950# define irqsafe_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
951 __pcpu_double_call_return_bool(irqsafe_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
952#endif
953
954#endif /* __LINUX_PERCPU_H */