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1#ifndef __LINUX_PERCPU_H
2#define __LINUX_PERCPU_H
3
4#include <linux/mmdebug.h>
5#include <linux/preempt.h>
6#include <linux/smp.h>
7#include <linux/cpumask.h>
8#include <linux/pfn.h>
9#include <linux/init.h>
10
11#include <asm/percpu.h>
12
13/* enough to cover all DEFINE_PER_CPUs in modules */
14#ifdef CONFIG_MODULES
15#define PERCPU_MODULE_RESERVE (8 << 10)
16#else
17#define PERCPU_MODULE_RESERVE 0
18#endif
19
20#ifndef PERCPU_ENOUGH_ROOM
21#define PERCPU_ENOUGH_ROOM \
22 (ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES) + \
23 PERCPU_MODULE_RESERVE)
24#endif
25
26/*
27 * Must be an lvalue. Since @var must be a simple identifier,
28 * we force a syntax error here if it isn't.
29 */
30#define get_cpu_var(var) (*({ \
31 preempt_disable(); \
32 &__get_cpu_var(var); }))
33
34/*
35 * The weird & is necessary because sparse considers (void)(var) to be
36 * a direct dereference of percpu variable (var).
37 */
38#define put_cpu_var(var) do { \
39 (void)&(var); \
40 preempt_enable(); \
41} while (0)
42
43#define get_cpu_ptr(var) ({ \
44 preempt_disable(); \
45 this_cpu_ptr(var); })
46
47#define put_cpu_ptr(var) do { \
48 (void)(var); \
49 preempt_enable(); \
50} while (0)
51
52/* minimum unit size, also is the maximum supported allocation size */
53#define PCPU_MIN_UNIT_SIZE PFN_ALIGN(32 << 10)
54
55/*
56 * Percpu allocator can serve percpu allocations before slab is
57 * initialized which allows slab to depend on the percpu allocator.
58 * The following two parameters decide how much resource to
59 * preallocate for this. Keep PERCPU_DYNAMIC_RESERVE equal to or
60 * larger than PERCPU_DYNAMIC_EARLY_SIZE.
61 */
62#define PERCPU_DYNAMIC_EARLY_SLOTS 128
63#define PERCPU_DYNAMIC_EARLY_SIZE (12 << 10)
64
65/*
66 * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy
67 * back on the first chunk for dynamic percpu allocation if arch is
68 * manually allocating and mapping it for faster access (as a part of
69 * large page mapping for example).
70 *
71 * The following values give between one and two pages of free space
72 * after typical minimal boot (2-way SMP, single disk and NIC) with
73 * both defconfig and a distro config on x86_64 and 32. More
74 * intelligent way to determine this would be nice.
75 */
76#if BITS_PER_LONG > 32
77#define PERCPU_DYNAMIC_RESERVE (20 << 10)
78#else
79#define PERCPU_DYNAMIC_RESERVE (12 << 10)
80#endif
81
82extern void *pcpu_base_addr;
83extern const unsigned long *pcpu_unit_offsets;
84
85struct pcpu_group_info {
86 int nr_units; /* aligned # of units */
87 unsigned long base_offset; /* base address offset */
88 unsigned int *cpu_map; /* unit->cpu map, empty
89 * entries contain NR_CPUS */
90};
91
92struct pcpu_alloc_info {
93 size_t static_size;
94 size_t reserved_size;
95 size_t dyn_size;
96 size_t unit_size;
97 size_t atom_size;
98 size_t alloc_size;
99 size_t __ai_size; /* internal, don't use */
100 int nr_groups; /* 0 if grouping unnecessary */
101 struct pcpu_group_info groups[];
102};
103
104enum pcpu_fc {
105 PCPU_FC_AUTO,
106 PCPU_FC_EMBED,
107 PCPU_FC_PAGE,
108
109 PCPU_FC_NR,
110};
111extern const char * const pcpu_fc_names[PCPU_FC_NR];
112
113extern enum pcpu_fc pcpu_chosen_fc;
114
115typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
116 size_t align);
117typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
118typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
119typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
120
121extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
122 int nr_units);
123extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
124
125extern int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
126 void *base_addr);
127
128#ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
129extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
130 size_t atom_size,
131 pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
132 pcpu_fc_alloc_fn_t alloc_fn,
133 pcpu_fc_free_fn_t free_fn);
134#endif
135
136#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
137extern int __init pcpu_page_first_chunk(size_t reserved_size,
138 pcpu_fc_alloc_fn_t alloc_fn,
139 pcpu_fc_free_fn_t free_fn,
140 pcpu_fc_populate_pte_fn_t populate_pte_fn);
141#endif
142
143/*
144 * Use this to get to a cpu's version of the per-cpu object
145 * dynamically allocated. Non-atomic access to the current CPU's
146 * version should probably be combined with get_cpu()/put_cpu().
147 */
148#ifdef CONFIG_SMP
149#define per_cpu_ptr(ptr, cpu) SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu)))
150#else
151#define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); VERIFY_PERCPU_PTR((ptr)); })
152#endif
153
154extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
155extern bool is_kernel_percpu_address(unsigned long addr);
156
157#if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
158extern void __init setup_per_cpu_areas(void);
159#endif
160extern void __init percpu_init_late(void);
161
162extern void __percpu *__alloc_percpu(size_t size, size_t align);
163extern void free_percpu(void __percpu *__pdata);
164extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
165
166#define alloc_percpu(type) \
167 (typeof(type) __percpu *)__alloc_percpu(sizeof(type), __alignof__(type))
168
169/*
170 * Branching function to split up a function into a set of functions that
171 * are called for different scalar sizes of the objects handled.
172 */
173
174extern void __bad_size_call_parameter(void);
175
176#ifdef CONFIG_DEBUG_PREEMPT
177extern void __this_cpu_preempt_check(const char *op);
178#else
179static inline void __this_cpu_preempt_check(const char *op) { }
180#endif
181
182#define __pcpu_size_call_return(stem, variable) \
183({ typeof(variable) pscr_ret__; \
184 __verify_pcpu_ptr(&(variable)); \
185 switch(sizeof(variable)) { \
186 case 1: pscr_ret__ = stem##1(variable);break; \
187 case 2: pscr_ret__ = stem##2(variable);break; \
188 case 4: pscr_ret__ = stem##4(variable);break; \
189 case 8: pscr_ret__ = stem##8(variable);break; \
190 default: \
191 __bad_size_call_parameter();break; \
192 } \
193 pscr_ret__; \
194})
195
196#define __pcpu_size_call_return2(stem, variable, ...) \
197({ \
198 typeof(variable) pscr2_ret__; \
199 __verify_pcpu_ptr(&(variable)); \
200 switch(sizeof(variable)) { \
201 case 1: pscr2_ret__ = stem##1(variable, __VA_ARGS__); break; \
202 case 2: pscr2_ret__ = stem##2(variable, __VA_ARGS__); break; \
203 case 4: pscr2_ret__ = stem##4(variable, __VA_ARGS__); break; \
204 case 8: pscr2_ret__ = stem##8(variable, __VA_ARGS__); break; \
205 default: \
206 __bad_size_call_parameter(); break; \
207 } \
208 pscr2_ret__; \
209})
210
211/*
212 * Special handling for cmpxchg_double. cmpxchg_double is passed two
213 * percpu variables. The first has to be aligned to a double word
214 * boundary and the second has to follow directly thereafter.
215 * We enforce this on all architectures even if they don't support
216 * a double cmpxchg instruction, since it's a cheap requirement, and it
217 * avoids breaking the requirement for architectures with the instruction.
218 */
219#define __pcpu_double_call_return_bool(stem, pcp1, pcp2, ...) \
220({ \
221 bool pdcrb_ret__; \
222 __verify_pcpu_ptr(&pcp1); \
223 BUILD_BUG_ON(sizeof(pcp1) != sizeof(pcp2)); \
224 VM_BUG_ON((unsigned long)(&pcp1) % (2 * sizeof(pcp1))); \
225 VM_BUG_ON((unsigned long)(&pcp2) != \
226 (unsigned long)(&pcp1) + sizeof(pcp1)); \
227 switch(sizeof(pcp1)) { \
228 case 1: pdcrb_ret__ = stem##1(pcp1, pcp2, __VA_ARGS__); break; \
229 case 2: pdcrb_ret__ = stem##2(pcp1, pcp2, __VA_ARGS__); break; \
230 case 4: pdcrb_ret__ = stem##4(pcp1, pcp2, __VA_ARGS__); break; \
231 case 8: pdcrb_ret__ = stem##8(pcp1, pcp2, __VA_ARGS__); break; \
232 default: \
233 __bad_size_call_parameter(); break; \
234 } \
235 pdcrb_ret__; \
236})
237
238#define __pcpu_size_call(stem, variable, ...) \
239do { \
240 __verify_pcpu_ptr(&(variable)); \
241 switch(sizeof(variable)) { \
242 case 1: stem##1(variable, __VA_ARGS__);break; \
243 case 2: stem##2(variable, __VA_ARGS__);break; \
244 case 4: stem##4(variable, __VA_ARGS__);break; \
245 case 8: stem##8(variable, __VA_ARGS__);break; \
246 default: \
247 __bad_size_call_parameter();break; \
248 } \
249} while (0)
250
251/*
252 * this_cpu operations (C) 2008-2013 Christoph Lameter <cl@linux.com>
253 *
254 * Optimized manipulation for memory allocated through the per cpu
255 * allocator or for addresses of per cpu variables.
256 *
257 * These operation guarantee exclusivity of access for other operations
258 * on the *same* processor. The assumption is that per cpu data is only
259 * accessed by a single processor instance (the current one).
260 *
261 * The first group is used for accesses that must be done in a
262 * preemption safe way since we know that the context is not preempt
263 * safe. Interrupts may occur. If the interrupt modifies the variable
264 * too then RMW actions will not be reliable.
265 *
266 * The arch code can provide optimized functions in two ways:
267 *
268 * 1. Override the function completely. F.e. define this_cpu_add().
269 * The arch must then ensure that the various scalar format passed
270 * are handled correctly.
271 *
272 * 2. Provide functions for certain scalar sizes. F.e. provide
273 * this_cpu_add_2() to provide per cpu atomic operations for 2 byte
274 * sized RMW actions. If arch code does not provide operations for
275 * a scalar size then the fallback in the generic code will be
276 * used.
277 */
278
279#define _this_cpu_generic_read(pcp) \
280({ typeof(pcp) ret__; \
281 preempt_disable(); \
282 ret__ = *this_cpu_ptr(&(pcp)); \
283 preempt_enable(); \
284 ret__; \
285})
286
287#ifndef this_cpu_read
288# ifndef this_cpu_read_1
289# define this_cpu_read_1(pcp) _this_cpu_generic_read(pcp)
290# endif
291# ifndef this_cpu_read_2
292# define this_cpu_read_2(pcp) _this_cpu_generic_read(pcp)
293# endif
294# ifndef this_cpu_read_4
295# define this_cpu_read_4(pcp) _this_cpu_generic_read(pcp)
296# endif
297# ifndef this_cpu_read_8
298# define this_cpu_read_8(pcp) _this_cpu_generic_read(pcp)
299# endif
300# define this_cpu_read(pcp) __pcpu_size_call_return(this_cpu_read_, (pcp))
301#endif
302
303#define _this_cpu_generic_to_op(pcp, val, op) \
304do { \
305 unsigned long flags; \
306 raw_local_irq_save(flags); \
307 *raw_cpu_ptr(&(pcp)) op val; \
308 raw_local_irq_restore(flags); \
309} while (0)
310
311#ifndef this_cpu_write
312# ifndef this_cpu_write_1
313# define this_cpu_write_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), =)
314# endif
315# ifndef this_cpu_write_2
316# define this_cpu_write_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), =)
317# endif
318# ifndef this_cpu_write_4
319# define this_cpu_write_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), =)
320# endif
321# ifndef this_cpu_write_8
322# define this_cpu_write_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), =)
323# endif
324# define this_cpu_write(pcp, val) __pcpu_size_call(this_cpu_write_, (pcp), (val))
325#endif
326
327#ifndef this_cpu_add
328# ifndef this_cpu_add_1
329# define this_cpu_add_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=)
330# endif
331# ifndef this_cpu_add_2
332# define this_cpu_add_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=)
333# endif
334# ifndef this_cpu_add_4
335# define this_cpu_add_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=)
336# endif
337# ifndef this_cpu_add_8
338# define this_cpu_add_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=)
339# endif
340# define this_cpu_add(pcp, val) __pcpu_size_call(this_cpu_add_, (pcp), (val))
341#endif
342
343#ifndef this_cpu_sub
344# define this_cpu_sub(pcp, val) this_cpu_add((pcp), -(typeof(pcp))(val))
345#endif
346
347#ifndef this_cpu_inc
348# define this_cpu_inc(pcp) this_cpu_add((pcp), 1)
349#endif
350
351#ifndef this_cpu_dec
352# define this_cpu_dec(pcp) this_cpu_sub((pcp), 1)
353#endif
354
355#ifndef this_cpu_and
356# ifndef this_cpu_and_1
357# define this_cpu_and_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=)
358# endif
359# ifndef this_cpu_and_2
360# define this_cpu_and_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=)
361# endif
362# ifndef this_cpu_and_4
363# define this_cpu_and_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=)
364# endif
365# ifndef this_cpu_and_8
366# define this_cpu_and_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=)
367# endif
368# define this_cpu_and(pcp, val) __pcpu_size_call(this_cpu_and_, (pcp), (val))
369#endif
370
371#ifndef this_cpu_or
372# ifndef this_cpu_or_1
373# define this_cpu_or_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=)
374# endif
375# ifndef this_cpu_or_2
376# define this_cpu_or_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=)
377# endif
378# ifndef this_cpu_or_4
379# define this_cpu_or_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=)
380# endif
381# ifndef this_cpu_or_8
382# define this_cpu_or_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=)
383# endif
384# define this_cpu_or(pcp, val) __pcpu_size_call(this_cpu_or_, (pcp), (val))
385#endif
386
387#define _this_cpu_generic_add_return(pcp, val) \
388({ \
389 typeof(pcp) ret__; \
390 unsigned long flags; \
391 raw_local_irq_save(flags); \
392 raw_cpu_add(pcp, val); \
393 ret__ = raw_cpu_read(pcp); \
394 raw_local_irq_restore(flags); \
395 ret__; \
396})
397
398#ifndef this_cpu_add_return
399# ifndef this_cpu_add_return_1
400# define this_cpu_add_return_1(pcp, val) _this_cpu_generic_add_return(pcp, val)
401# endif
402# ifndef this_cpu_add_return_2
403# define this_cpu_add_return_2(pcp, val) _this_cpu_generic_add_return(pcp, val)
404# endif
405# ifndef this_cpu_add_return_4
406# define this_cpu_add_return_4(pcp, val) _this_cpu_generic_add_return(pcp, val)
407# endif
408# ifndef this_cpu_add_return_8
409# define this_cpu_add_return_8(pcp, val) _this_cpu_generic_add_return(pcp, val)
410# endif
411# define this_cpu_add_return(pcp, val) __pcpu_size_call_return2(this_cpu_add_return_, pcp, val)
412#endif
413
414#define this_cpu_sub_return(pcp, val) this_cpu_add_return(pcp, -(typeof(pcp))(val))
415#define this_cpu_inc_return(pcp) this_cpu_add_return(pcp, 1)
416#define this_cpu_dec_return(pcp) this_cpu_add_return(pcp, -1)
417
418#define _this_cpu_generic_xchg(pcp, nval) \
419({ typeof(pcp) ret__; \
420 unsigned long flags; \
421 raw_local_irq_save(flags); \
422 ret__ = raw_cpu_read(pcp); \
423 raw_cpu_write(pcp, nval); \
424 raw_local_irq_restore(flags); \
425 ret__; \
426})
427
428#ifndef this_cpu_xchg
429# ifndef this_cpu_xchg_1
430# define this_cpu_xchg_1(pcp, nval) _this_cpu_generic_xchg(pcp, nval)
431# endif
432# ifndef this_cpu_xchg_2
433# define this_cpu_xchg_2(pcp, nval) _this_cpu_generic_xchg(pcp, nval)
434# endif
435# ifndef this_cpu_xchg_4
436# define this_cpu_xchg_4(pcp, nval) _this_cpu_generic_xchg(pcp, nval)
437# endif
438# ifndef this_cpu_xchg_8
439# define this_cpu_xchg_8(pcp, nval) _this_cpu_generic_xchg(pcp, nval)
440# endif
441# define this_cpu_xchg(pcp, nval) \
442 __pcpu_size_call_return2(this_cpu_xchg_, (pcp), nval)
443#endif
444
445#define _this_cpu_generic_cmpxchg(pcp, oval, nval) \
446({ \
447 typeof(pcp) ret__; \
448 unsigned long flags; \
449 raw_local_irq_save(flags); \
450 ret__ = raw_cpu_read(pcp); \
451 if (ret__ == (oval)) \
452 raw_cpu_write(pcp, nval); \
453 raw_local_irq_restore(flags); \
454 ret__; \
455})
456
457#ifndef this_cpu_cmpxchg
458# ifndef this_cpu_cmpxchg_1
459# define this_cpu_cmpxchg_1(pcp, oval, nval) _this_cpu_generic_cmpxchg(pcp, oval, nval)
460# endif
461# ifndef this_cpu_cmpxchg_2
462# define this_cpu_cmpxchg_2(pcp, oval, nval) _this_cpu_generic_cmpxchg(pcp, oval, nval)
463# endif
464# ifndef this_cpu_cmpxchg_4
465# define this_cpu_cmpxchg_4(pcp, oval, nval) _this_cpu_generic_cmpxchg(pcp, oval, nval)
466# endif
467# ifndef this_cpu_cmpxchg_8
468# define this_cpu_cmpxchg_8(pcp, oval, nval) _this_cpu_generic_cmpxchg(pcp, oval, nval)
469# endif
470# define this_cpu_cmpxchg(pcp, oval, nval) \
471 __pcpu_size_call_return2(this_cpu_cmpxchg_, pcp, oval, nval)
472#endif
473
474/*
475 * cmpxchg_double replaces two adjacent scalars at once. The first
476 * two parameters are per cpu variables which have to be of the same
477 * size. A truth value is returned to indicate success or failure
478 * (since a double register result is difficult to handle). There is
479 * very limited hardware support for these operations, so only certain
480 * sizes may work.
481 */
482#define _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
483({ \
484 int ret__; \
485 unsigned long flags; \
486 raw_local_irq_save(flags); \
487 ret__ = raw_cpu_generic_cmpxchg_double(pcp1, pcp2, \
488 oval1, oval2, nval1, nval2); \
489 raw_local_irq_restore(flags); \
490 ret__; \
491})
492
493#ifndef this_cpu_cmpxchg_double
494# ifndef this_cpu_cmpxchg_double_1
495# define this_cpu_cmpxchg_double_1(pcp1, pcp2, oval1, oval2, nval1, nval2) \
496 _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
497# endif
498# ifndef this_cpu_cmpxchg_double_2
499# define this_cpu_cmpxchg_double_2(pcp1, pcp2, oval1, oval2, nval1, nval2) \
500 _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
501# endif
502# ifndef this_cpu_cmpxchg_double_4
503# define this_cpu_cmpxchg_double_4(pcp1, pcp2, oval1, oval2, nval1, nval2) \
504 _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
505# endif
506# ifndef this_cpu_cmpxchg_double_8
507# define this_cpu_cmpxchg_double_8(pcp1, pcp2, oval1, oval2, nval1, nval2) \
508 _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
509# endif
510# define this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
511 __pcpu_double_call_return_bool(this_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
512#endif
513
514/*
515 * Generic percpu operations for contexts where we do not want to do
516 * any checks for preemptiosn.
517 *
518 * If there is no other protection through preempt disable and/or
519 * disabling interupts then one of these RMW operations can show unexpected
520 * behavior because the execution thread was rescheduled on another processor
521 * or an interrupt occurred and the same percpu variable was modified from
522 * the interrupt context.
523 */
524#ifndef raw_cpu_read
525# ifndef raw_cpu_read_1
526# define raw_cpu_read_1(pcp) (*raw_cpu_ptr(&(pcp)))
527# endif
528# ifndef raw_cpu_read_2
529# define raw_cpu_read_2(pcp) (*raw_cpu_ptr(&(pcp)))
530# endif
531# ifndef raw_cpu_read_4
532# define raw_cpu_read_4(pcp) (*raw_cpu_ptr(&(pcp)))
533# endif
534# ifndef raw_cpu_read_8
535# define raw_cpu_read_8(pcp) (*raw_cpu_ptr(&(pcp)))
536# endif
537# define raw_cpu_read(pcp) __pcpu_size_call_return(raw_cpu_read_, (pcp))
538#endif
539
540#define raw_cpu_generic_to_op(pcp, val, op) \
541do { \
542 *raw_cpu_ptr(&(pcp)) op val; \
543} while (0)
544
545
546#ifndef raw_cpu_write
547# ifndef raw_cpu_write_1
548# define raw_cpu_write_1(pcp, val) raw_cpu_generic_to_op((pcp), (val), =)
549# endif
550# ifndef raw_cpu_write_2
551# define raw_cpu_write_2(pcp, val) raw_cpu_generic_to_op((pcp), (val), =)
552# endif
553# ifndef raw_cpu_write_4
554# define raw_cpu_write_4(pcp, val) raw_cpu_generic_to_op((pcp), (val), =)
555# endif
556# ifndef raw_cpu_write_8
557# define raw_cpu_write_8(pcp, val) raw_cpu_generic_to_op((pcp), (val), =)
558# endif
559# define raw_cpu_write(pcp, val) __pcpu_size_call(raw_cpu_write_, (pcp), (val))
560#endif
561
562#ifndef raw_cpu_add
563# ifndef raw_cpu_add_1
564# define raw_cpu_add_1(pcp, val) raw_cpu_generic_to_op((pcp), (val), +=)
565# endif
566# ifndef raw_cpu_add_2
567# define raw_cpu_add_2(pcp, val) raw_cpu_generic_to_op((pcp), (val), +=)
568# endif
569# ifndef raw_cpu_add_4
570# define raw_cpu_add_4(pcp, val) raw_cpu_generic_to_op((pcp), (val), +=)
571# endif
572# ifndef raw_cpu_add_8
573# define raw_cpu_add_8(pcp, val) raw_cpu_generic_to_op((pcp), (val), +=)
574# endif
575# define raw_cpu_add(pcp, val) __pcpu_size_call(raw_cpu_add_, (pcp), (val))
576#endif
577
578#ifndef raw_cpu_sub
579# define raw_cpu_sub(pcp, val) raw_cpu_add((pcp), -(val))
580#endif
581
582#ifndef raw_cpu_inc
583# define raw_cpu_inc(pcp) raw_cpu_add((pcp), 1)
584#endif
585
586#ifndef raw_cpu_dec
587# define raw_cpu_dec(pcp) raw_cpu_sub((pcp), 1)
588#endif
589
590#ifndef raw_cpu_and
591# ifndef raw_cpu_and_1
592# define raw_cpu_and_1(pcp, val) raw_cpu_generic_to_op((pcp), (val), &=)
593# endif
594# ifndef raw_cpu_and_2
595# define raw_cpu_and_2(pcp, val) raw_cpu_generic_to_op((pcp), (val), &=)
596# endif
597# ifndef raw_cpu_and_4
598# define raw_cpu_and_4(pcp, val) raw_cpu_generic_to_op((pcp), (val), &=)
599# endif
600# ifndef raw_cpu_and_8
601# define raw_cpu_and_8(pcp, val) raw_cpu_generic_to_op((pcp), (val), &=)
602# endif
603# define raw_cpu_and(pcp, val) __pcpu_size_call(raw_cpu_and_, (pcp), (val))
604#endif
605
606#ifndef raw_cpu_or
607# ifndef raw_cpu_or_1
608# define raw_cpu_or_1(pcp, val) raw_cpu_generic_to_op((pcp), (val), |=)
609# endif
610# ifndef raw_cpu_or_2
611# define raw_cpu_or_2(pcp, val) raw_cpu_generic_to_op((pcp), (val), |=)
612# endif
613# ifndef raw_cpu_or_4
614# define raw_cpu_or_4(pcp, val) raw_cpu_generic_to_op((pcp), (val), |=)
615# endif
616# ifndef raw_cpu_or_8
617# define raw_cpu_or_8(pcp, val) raw_cpu_generic_to_op((pcp), (val), |=)
618# endif
619# define raw_cpu_or(pcp, val) __pcpu_size_call(raw_cpu_or_, (pcp), (val))
620#endif
621
622#define raw_cpu_generic_add_return(pcp, val) \
623({ \
624 raw_cpu_add(pcp, val); \
625 raw_cpu_read(pcp); \
626})
627
628#ifndef raw_cpu_add_return
629# ifndef raw_cpu_add_return_1
630# define raw_cpu_add_return_1(pcp, val) raw_cpu_generic_add_return(pcp, val)
631# endif
632# ifndef raw_cpu_add_return_2
633# define raw_cpu_add_return_2(pcp, val) raw_cpu_generic_add_return(pcp, val)
634# endif
635# ifndef raw_cpu_add_return_4
636# define raw_cpu_add_return_4(pcp, val) raw_cpu_generic_add_return(pcp, val)
637# endif
638# ifndef raw_cpu_add_return_8
639# define raw_cpu_add_return_8(pcp, val) raw_cpu_generic_add_return(pcp, val)
640# endif
641# define raw_cpu_add_return(pcp, val) \
642 __pcpu_size_call_return2(raw_add_return_, pcp, val)
643#endif
644
645#define raw_cpu_sub_return(pcp, val) raw_cpu_add_return(pcp, -(typeof(pcp))(val))
646#define raw_cpu_inc_return(pcp) raw_cpu_add_return(pcp, 1)
647#define raw_cpu_dec_return(pcp) raw_cpu_add_return(pcp, -1)
648
649#define raw_cpu_generic_xchg(pcp, nval) \
650({ typeof(pcp) ret__; \
651 ret__ = raw_cpu_read(pcp); \
652 raw_cpu_write(pcp, nval); \
653 ret__; \
654})
655
656#ifndef raw_cpu_xchg
657# ifndef raw_cpu_xchg_1
658# define raw_cpu_xchg_1(pcp, nval) raw_cpu_generic_xchg(pcp, nval)
659# endif
660# ifndef raw_cpu_xchg_2
661# define raw_cpu_xchg_2(pcp, nval) raw_cpu_generic_xchg(pcp, nval)
662# endif
663# ifndef raw_cpu_xchg_4
664# define raw_cpu_xchg_4(pcp, nval) raw_cpu_generic_xchg(pcp, nval)
665# endif
666# ifndef raw_cpu_xchg_8
667# define raw_cpu_xchg_8(pcp, nval) raw_cpu_generic_xchg(pcp, nval)
668# endif
669# define raw_cpu_xchg(pcp, nval) \
670 __pcpu_size_call_return2(raw_cpu_xchg_, (pcp), nval)
671#endif
672
673#define raw_cpu_generic_cmpxchg(pcp, oval, nval) \
674({ \
675 typeof(pcp) ret__; \
676 ret__ = raw_cpu_read(pcp); \
677 if (ret__ == (oval)) \
678 raw_cpu_write(pcp, nval); \
679 ret__; \
680})
681
682#ifndef raw_cpu_cmpxchg
683# ifndef raw_cpu_cmpxchg_1
684# define raw_cpu_cmpxchg_1(pcp, oval, nval) raw_cpu_generic_cmpxchg(pcp, oval, nval)
685# endif
686# ifndef raw_cpu_cmpxchg_2
687# define raw_cpu_cmpxchg_2(pcp, oval, nval) raw_cpu_generic_cmpxchg(pcp, oval, nval)
688# endif
689# ifndef raw_cpu_cmpxchg_4
690# define raw_cpu_cmpxchg_4(pcp, oval, nval) raw_cpu_generic_cmpxchg(pcp, oval, nval)
691# endif
692# ifndef raw_cpu_cmpxchg_8
693# define raw_cpu_cmpxchg_8(pcp, oval, nval) raw_cpu_generic_cmpxchg(pcp, oval, nval)
694# endif
695# define raw_cpu_cmpxchg(pcp, oval, nval) \
696 __pcpu_size_call_return2(raw_cpu_cmpxchg_, pcp, oval, nval)
697#endif
698
699#define raw_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
700({ \
701 int __ret = 0; \
702 if (raw_cpu_read(pcp1) == (oval1) && \
703 raw_cpu_read(pcp2) == (oval2)) { \
704 raw_cpu_write(pcp1, (nval1)); \
705 raw_cpu_write(pcp2, (nval2)); \
706 __ret = 1; \
707 } \
708 (__ret); \
709})
710
711#ifndef raw_cpu_cmpxchg_double
712# ifndef raw_cpu_cmpxchg_double_1
713# define raw_cpu_cmpxchg_double_1(pcp1, pcp2, oval1, oval2, nval1, nval2) \
714 raw_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
715# endif
716# ifndef raw_cpu_cmpxchg_double_2
717# define raw_cpu_cmpxchg_double_2(pcp1, pcp2, oval1, oval2, nval1, nval2) \
718 raw_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
719# endif
720# ifndef raw_cpu_cmpxchg_double_4
721# define raw_cpu_cmpxchg_double_4(pcp1, pcp2, oval1, oval2, nval1, nval2) \
722 raw_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
723# endif
724# ifndef raw_cpu_cmpxchg_double_8
725# define raw_cpu_cmpxchg_double_8(pcp1, pcp2, oval1, oval2, nval1, nval2) \
726 raw_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
727# endif
728# define raw_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
729 __pcpu_double_call_return_bool(raw_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
730#endif
731
732/*
733 * Generic percpu operations for context that are safe from preemption/interrupts.
734 */
735#ifndef __this_cpu_read
736# define __this_cpu_read(pcp) \
737 (__this_cpu_preempt_check("read"),__pcpu_size_call_return(raw_cpu_read_, (pcp)))
738#endif
739
740#ifndef __this_cpu_write
741# define __this_cpu_write(pcp, val) \
742do { __this_cpu_preempt_check("write"); \
743 __pcpu_size_call(raw_cpu_write_, (pcp), (val)); \
744} while (0)
745#endif
746
747#ifndef __this_cpu_add
748# define __this_cpu_add(pcp, val) \
749do { __this_cpu_preempt_check("add"); \
750 __pcpu_size_call(raw_cpu_add_, (pcp), (val)); \
751} while (0)
752#endif
753
754#ifndef __this_cpu_sub
755# define __this_cpu_sub(pcp, val) __this_cpu_add((pcp), -(typeof(pcp))(val))
756#endif
757
758#ifndef __this_cpu_inc
759# define __this_cpu_inc(pcp) __this_cpu_add((pcp), 1)
760#endif
761
762#ifndef __this_cpu_dec
763# define __this_cpu_dec(pcp) __this_cpu_sub((pcp), 1)
764#endif
765
766#ifndef __this_cpu_and
767# define __this_cpu_and(pcp, val) \
768do { __this_cpu_preempt_check("and"); \
769 __pcpu_size_call(raw_cpu_and_, (pcp), (val)); \
770} while (0)
771
772#endif
773
774#ifndef __this_cpu_or
775# define __this_cpu_or(pcp, val) \
776do { __this_cpu_preempt_check("or"); \
777 __pcpu_size_call(raw_cpu_or_, (pcp), (val)); \
778} while (0)
779#endif
780
781#ifndef __this_cpu_add_return
782# define __this_cpu_add_return(pcp, val) \
783 (__this_cpu_preempt_check("add_return"),__pcpu_size_call_return2(raw_cpu_add_return_, pcp, val))
784#endif
785
786#define __this_cpu_sub_return(pcp, val) __this_cpu_add_return(pcp, -(typeof(pcp))(val))
787#define __this_cpu_inc_return(pcp) __this_cpu_add_return(pcp, 1)
788#define __this_cpu_dec_return(pcp) __this_cpu_add_return(pcp, -1)
789
790#ifndef __this_cpu_xchg
791# define __this_cpu_xchg(pcp, nval) \
792 (__this_cpu_preempt_check("xchg"),__pcpu_size_call_return2(raw_cpu_xchg_, (pcp), nval))
793#endif
794
795#ifndef __this_cpu_cmpxchg
796# define __this_cpu_cmpxchg(pcp, oval, nval) \
797 (__this_cpu_preempt_check("cmpxchg"),__pcpu_size_call_return2(raw_cpu_cmpxchg_, pcp, oval, nval))
798#endif
799
800#ifndef __this_cpu_cmpxchg_double
801# define __this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
802 (__this_cpu_preempt_check("cmpxchg_double"),__pcpu_double_call_return_bool(raw_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2)))
803#endif
804
805#endif /* __LINUX_PERCPU_H */
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __LINUX_PERCPU_H
3#define __LINUX_PERCPU_H
4
5#include <linux/mmdebug.h>
6#include <linux/preempt.h>
7#include <linux/smp.h>
8#include <linux/cpumask.h>
9#include <linux/printk.h>
10#include <linux/pfn.h>
11#include <linux/init.h>
12
13#include <asm/percpu.h>
14
15/* enough to cover all DEFINE_PER_CPUs in modules */
16#ifdef CONFIG_MODULES
17#define PERCPU_MODULE_RESERVE (8 << 10)
18#else
19#define PERCPU_MODULE_RESERVE 0
20#endif
21
22/* minimum unit size, also is the maximum supported allocation size */
23#define PCPU_MIN_UNIT_SIZE PFN_ALIGN(32 << 10)
24
25/* minimum allocation size and shift in bytes */
26#define PCPU_MIN_ALLOC_SHIFT 2
27#define PCPU_MIN_ALLOC_SIZE (1 << PCPU_MIN_ALLOC_SHIFT)
28
29/* number of bits per page, used to trigger a scan if blocks are > PAGE_SIZE */
30#define PCPU_BITS_PER_PAGE (PAGE_SIZE >> PCPU_MIN_ALLOC_SHIFT)
31
32/*
33 * This determines the size of each metadata block. There are several subtle
34 * constraints around this constant. The reserved region must be a multiple of
35 * PCPU_BITMAP_BLOCK_SIZE. Additionally, PCPU_BITMAP_BLOCK_SIZE must be a
36 * multiple of PAGE_SIZE or PAGE_SIZE must be a multiple of
37 * PCPU_BITMAP_BLOCK_SIZE to align with the populated page map. The unit_size
38 * also has to be a multiple of PCPU_BITMAP_BLOCK_SIZE to ensure full blocks.
39 */
40#define PCPU_BITMAP_BLOCK_SIZE PAGE_SIZE
41#define PCPU_BITMAP_BLOCK_BITS (PCPU_BITMAP_BLOCK_SIZE >> \
42 PCPU_MIN_ALLOC_SHIFT)
43
44/*
45 * Percpu allocator can serve percpu allocations before slab is
46 * initialized which allows slab to depend on the percpu allocator.
47 * The following two parameters decide how much resource to
48 * preallocate for this. Keep PERCPU_DYNAMIC_RESERVE equal to or
49 * larger than PERCPU_DYNAMIC_EARLY_SIZE.
50 */
51#define PERCPU_DYNAMIC_EARLY_SLOTS 128
52#define PERCPU_DYNAMIC_EARLY_SIZE (12 << 10)
53
54/*
55 * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy
56 * back on the first chunk for dynamic percpu allocation if arch is
57 * manually allocating and mapping it for faster access (as a part of
58 * large page mapping for example).
59 *
60 * The following values give between one and two pages of free space
61 * after typical minimal boot (2-way SMP, single disk and NIC) with
62 * both defconfig and a distro config on x86_64 and 32. More
63 * intelligent way to determine this would be nice.
64 */
65#if BITS_PER_LONG > 32
66#define PERCPU_DYNAMIC_RESERVE (28 << 10)
67#else
68#define PERCPU_DYNAMIC_RESERVE (20 << 10)
69#endif
70
71extern void *pcpu_base_addr;
72extern const unsigned long *pcpu_unit_offsets;
73
74struct pcpu_group_info {
75 int nr_units; /* aligned # of units */
76 unsigned long base_offset; /* base address offset */
77 unsigned int *cpu_map; /* unit->cpu map, empty
78 * entries contain NR_CPUS */
79};
80
81struct pcpu_alloc_info {
82 size_t static_size;
83 size_t reserved_size;
84 size_t dyn_size;
85 size_t unit_size;
86 size_t atom_size;
87 size_t alloc_size;
88 size_t __ai_size; /* internal, don't use */
89 int nr_groups; /* 0 if grouping unnecessary */
90 struct pcpu_group_info groups[];
91};
92
93enum pcpu_fc {
94 PCPU_FC_AUTO,
95 PCPU_FC_EMBED,
96 PCPU_FC_PAGE,
97
98 PCPU_FC_NR,
99};
100extern const char * const pcpu_fc_names[PCPU_FC_NR];
101
102extern enum pcpu_fc pcpu_chosen_fc;
103
104typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
105 size_t align);
106typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
107typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
108typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
109
110extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
111 int nr_units);
112extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
113
114extern int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
115 void *base_addr);
116
117#ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
118extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
119 size_t atom_size,
120 pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
121 pcpu_fc_alloc_fn_t alloc_fn,
122 pcpu_fc_free_fn_t free_fn);
123#endif
124
125#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
126extern int __init pcpu_page_first_chunk(size_t reserved_size,
127 pcpu_fc_alloc_fn_t alloc_fn,
128 pcpu_fc_free_fn_t free_fn,
129 pcpu_fc_populate_pte_fn_t populate_pte_fn);
130#endif
131
132extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
133extern bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr);
134extern bool is_kernel_percpu_address(unsigned long addr);
135
136#if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
137extern void __init setup_per_cpu_areas(void);
138#endif
139
140extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp);
141extern void __percpu *__alloc_percpu(size_t size, size_t align);
142extern void free_percpu(void __percpu *__pdata);
143extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
144
145#define alloc_percpu_gfp(type, gfp) \
146 (typeof(type) __percpu *)__alloc_percpu_gfp(sizeof(type), \
147 __alignof__(type), gfp)
148#define alloc_percpu(type) \
149 (typeof(type) __percpu *)__alloc_percpu(sizeof(type), \
150 __alignof__(type))
151
152#endif /* __LINUX_PERCPU_H */