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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef __LINUX_PERCPU_H
2#define __LINUX_PERCPU_H
Martin Peschke7ff6f082006-09-25 23:31:21 -07003
Robert P. J. Day0a3021f2007-07-15 23:39:57 -07004#include <linux/preempt.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07005#include <linux/smp.h>
Martin Peschke7ff6f082006-09-25 23:31:21 -07006#include <linux/cpumask.h>
Tejun Heo6a242902009-03-06 14:33:58 +09007#include <linux/pfn.h>
Tejun Heode380b52010-03-24 17:06:43 +09008#include <linux/init.h>
Martin Peschke7ff6f082006-09-25 23:31:21 -07009
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <asm/percpu.h>
11
Tejun Heo6a242902009-03-06 14:33:58 +090012/* enough to cover all DEFINE_PER_CPUs in modules */
Jeremy Fitzhardingeb00742d32007-05-02 19:27:11 +020013#ifdef CONFIG_MODULES
Tejun Heo6a242902009-03-06 14:33:58 +090014#define PERCPU_MODULE_RESERVE (8 << 10)
Jeremy Fitzhardingeb00742d32007-05-02 19:27:11 +020015#else
Tejun Heo6a242902009-03-06 14:33:58 +090016#define PERCPU_MODULE_RESERVE 0
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#endif
18
Tejun Heo6a242902009-03-06 14:33:58 +090019#ifndef PERCPU_ENOUGH_ROOM
Jeremy Fitzhardingeb00742d32007-05-02 19:27:11 +020020#define PERCPU_ENOUGH_ROOM \
Tejun Heo6a242902009-03-06 14:33:58 +090021 (ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES) + \
22 PERCPU_MODULE_RESERVE)
23#endif
Jeremy Fitzhardingeb00742d32007-05-02 19:27:11 +020024
Jan Blunck632bbfe2006-09-25 23:30:53 -070025/*
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) (*({ \
Jan Blunck632bbfe2006-09-25 23:30:53 -070030 preempt_disable(); \
31 &__get_cpu_var(var); }))
Tejun Heof7b64fe2009-10-29 22:34:15 +090032
Rusty Russelle0fdb0e2009-10-29 22:34:15 +090033/*
34 * The weird & is necessary because sparse considers (void)(var) to be
35 * a direct dereference of percpu variable (var).
36 */
Tejun Heof7b64fe2009-10-29 22:34:15 +090037#define put_cpu_var(var) do { \
Rusty Russelle0fdb0e2009-10-29 22:34:15 +090038 (void)&(var); \
Tejun Heof7b64fe2009-10-29 22:34:15 +090039 preempt_enable(); \
40} while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
Peter Zijlstra8b8e2ec2010-09-16 19:21:28 +020042#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
Linus Torvalds1da177e2005-04-16 15:20:36 -070051#ifdef CONFIG_SMP
52
Tejun Heo8d408b42009-02-24 11:57:21 +090053/* minimum unit size, also is the maximum supported allocation size */
Tejun Heo6a242902009-03-06 14:33:58 +090054#define PCPU_MIN_UNIT_SIZE PFN_ALIGN(64 << 10)
Tejun Heo8d408b42009-02-24 11:57:21 +090055
56/*
Tejun Heo099a19d2010-06-27 18:50:00 +020057 * Percpu allocator can serve percpu allocations before slab is
58 * initialized which allows slab to depend on the percpu allocator.
59 * The following two parameters decide how much resource to
60 * preallocate for this. Keep PERCPU_DYNAMIC_RESERVE equal to or
61 * larger than PERCPU_DYNAMIC_EARLY_SIZE.
62 */
63#define PERCPU_DYNAMIC_EARLY_SLOTS 128
64#define PERCPU_DYNAMIC_EARLY_SIZE (12 << 10)
65
66/*
Tejun Heo8d408b42009-02-24 11:57:21 +090067 * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy
Tejun Heo6b19b0c2009-03-06 14:33:59 +090068 * back on the first chunk for dynamic percpu allocation if arch is
69 * manually allocating and mapping it for faster access (as a part of
70 * large page mapping for example).
Tejun Heo8d408b42009-02-24 11:57:21 +090071 *
Tejun Heo6b19b0c2009-03-06 14:33:59 +090072 * The following values give between one and two pages of free space
73 * after typical minimal boot (2-way SMP, single disk and NIC) with
74 * both defconfig and a distro config on x86_64 and 32. More
75 * intelligent way to determine this would be nice.
Tejun Heo8d408b42009-02-24 11:57:21 +090076 */
Tejun Heo6b19b0c2009-03-06 14:33:59 +090077#if BITS_PER_LONG > 32
78#define PERCPU_DYNAMIC_RESERVE (20 << 10)
79#else
80#define PERCPU_DYNAMIC_RESERVE (12 << 10)
81#endif
Tejun Heo8d408b42009-02-24 11:57:21 +090082
Tejun Heofbf59bc2009-02-20 16:29:08 +090083extern void *pcpu_base_addr;
Tejun Heofb435d52009-08-14 15:00:51 +090084extern const unsigned long *pcpu_unit_offsets;
Tejun Heofbf59bc2009-02-20 16:29:08 +090085
Tejun Heofd1e8a12009-08-14 15:00:51 +090086struct pcpu_group_info {
87 int nr_units; /* aligned # of units */
88 unsigned long base_offset; /* base address offset */
89 unsigned int *cpu_map; /* unit->cpu map, empty
90 * entries contain NR_CPUS */
91};
92
93struct pcpu_alloc_info {
94 size_t static_size;
95 size_t reserved_size;
96 size_t dyn_size;
97 size_t unit_size;
98 size_t atom_size;
99 size_t alloc_size;
100 size_t __ai_size; /* internal, don't use */
101 int nr_groups; /* 0 if grouping unnecessary */
102 struct pcpu_group_info groups[];
103};
104
Tejun Heof58dc012009-08-14 15:00:50 +0900105enum pcpu_fc {
106 PCPU_FC_AUTO,
107 PCPU_FC_EMBED,
108 PCPU_FC_PAGE,
Tejun Heof58dc012009-08-14 15:00:50 +0900109
110 PCPU_FC_NR,
111};
112extern const char *pcpu_fc_names[PCPU_FC_NR];
113
114extern enum pcpu_fc pcpu_chosen_fc;
115
Tejun Heo3cbc8562009-08-14 15:00:50 +0900116typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
117 size_t align);
Tejun Heod4b95f82009-07-04 08:10:59 +0900118typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
119typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
Tejun Heoa530b792009-07-04 08:11:00 +0900120typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
Tejun Heofbf59bc2009-02-20 16:29:08 +0900121
Tejun Heofd1e8a12009-08-14 15:00:51 +0900122extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
123 int nr_units);
124extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
Tejun Heo033e48f2009-08-14 15:00:51 +0900125
Tejun Heofb435d52009-08-14 15:00:51 +0900126extern int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
127 void *base_addr);
Tejun Heo8d408b42009-02-24 11:57:21 +0900128
Tejun Heo08fc4582009-08-14 15:00:49 +0900129#ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
Tejun Heo4ba6ce22010-06-27 18:49:59 +0200130extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
Tejun Heoc8826dd2009-08-14 15:00:52 +0900131 size_t atom_size,
132 pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
133 pcpu_fc_alloc_fn_t alloc_fn,
134 pcpu_fc_free_fn_t free_fn);
Tejun Heo08fc4582009-08-14 15:00:49 +0900135#endif
Tejun Heo66c3a752009-03-10 16:27:48 +0900136
Tejun Heo08fc4582009-08-14 15:00:49 +0900137#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
Tejun Heofb435d52009-08-14 15:00:51 +0900138extern int __init pcpu_page_first_chunk(size_t reserved_size,
Tejun Heod4b95f82009-07-04 08:10:59 +0900139 pcpu_fc_alloc_fn_t alloc_fn,
140 pcpu_fc_free_fn_t free_fn,
141 pcpu_fc_populate_pte_fn_t populate_pte_fn);
Tejun Heo08fc4582009-08-14 15:00:49 +0900142#endif
Tejun Heod4b95f82009-07-04 08:10:59 +0900143
Tejun Heofbf59bc2009-02-20 16:29:08 +0900144/*
145 * Use this to get to a cpu's version of the per-cpu object
146 * dynamically allocated. Non-atomic access to the current CPU's
147 * version should probably be combined with get_cpu()/put_cpu().
148 */
149#define per_cpu_ptr(ptr, cpu) SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu)))
150
Rusty Russelle0fdb0e2009-10-29 22:34:15 +0900151extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
Tejun Heo10fad5e2010-03-10 18:57:54 +0900152extern bool is_kernel_percpu_address(unsigned long addr);
Tejun Heof2a82052009-02-20 16:29:08 +0900153
Tejun Heoe74e3962009-03-30 19:07:44 +0900154#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
155extern void __init setup_per_cpu_areas(void);
156#endif
Tejun Heo099a19d2010-06-27 18:50:00 +0200157extern void __init percpu_init_late(void);
Tejun Heoe74e3962009-03-30 19:07:44 +0900158
Tejun Heof2a82052009-02-20 16:29:08 +0900159#else /* CONFIG_SMP */
160
Namhyung Kim18cb2aef2010-08-07 03:26:23 +0900161#define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); VERIFY_PERCPU_PTR((ptr)); })
Tejun Heof2a82052009-02-20 16:29:08 +0900162
Tejun Heo10fad5e2010-03-10 18:57:54 +0900163/* can't distinguish from other static vars, always false */
164static inline bool is_kernel_percpu_address(unsigned long addr)
165{
166 return false;
167}
168
Tejun Heoe74e3962009-03-30 19:07:44 +0900169static inline void __init setup_per_cpu_areas(void) { }
170
Tejun Heo099a19d2010-06-27 18:50:00 +0200171static inline void __init percpu_init_late(void) { }
172
Tejun Heoa76761b2009-07-15 23:35:14 +0900173static inline void *pcpu_lpage_remapped(void *kaddr)
174{
175 return NULL;
176}
177
Tejun Heof2a82052009-02-20 16:29:08 +0900178#endif /* CONFIG_SMP */
179
Tejun Heode380b52010-03-24 17:06:43 +0900180extern void __percpu *__alloc_percpu(size_t size, size_t align);
181extern void free_percpu(void __percpu *__pdata);
182extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
183
Tejun Heo64ef2912009-10-29 22:34:12 +0900184#define alloc_percpu(type) \
Rusty Russelle0fdb0e2009-10-29 22:34:15 +0900185 (typeof(type) __percpu *)__alloc_percpu(sizeof(type), __alignof__(type))
Tejun Heof2a82052009-02-20 16:29:08 +0900186
Tejun Heo066123a2009-04-10 12:02:40 -0700187/*
188 * Optional methods for optimized non-lvalue per-cpu variable access.
189 *
190 * @var can be a percpu variable or a field of it and its size should
191 * equal char, int or long. percpu_read() evaluates to a lvalue and
192 * all others to void.
193 *
194 * These operations are guaranteed to be atomic w.r.t. preemption.
195 * The generic versions use plain get/put_cpu_var(). Archs are
196 * encouraged to implement single-instruction alternatives which don't
197 * require preemption protection.
198 */
199#ifndef percpu_read
200# define percpu_read(var) \
201 ({ \
Tejun Heof7b64fe2009-10-29 22:34:15 +0900202 typeof(var) *pr_ptr__ = &(var); \
203 typeof(var) pr_ret__; \
204 pr_ret__ = get_cpu_var(*pr_ptr__); \
205 put_cpu_var(*pr_ptr__); \
206 pr_ret__; \
Tejun Heo066123a2009-04-10 12:02:40 -0700207 })
208#endif
209
210#define __percpu_generic_to_op(var, val, op) \
211do { \
Tejun Heof7b64fe2009-10-29 22:34:15 +0900212 typeof(var) *pgto_ptr__ = &(var); \
213 get_cpu_var(*pgto_ptr__) op val; \
214 put_cpu_var(*pgto_ptr__); \
Tejun Heo066123a2009-04-10 12:02:40 -0700215} while (0)
216
217#ifndef percpu_write
218# define percpu_write(var, val) __percpu_generic_to_op(var, (val), =)
219#endif
220
221#ifndef percpu_add
222# define percpu_add(var, val) __percpu_generic_to_op(var, (val), +=)
223#endif
224
225#ifndef percpu_sub
226# define percpu_sub(var, val) __percpu_generic_to_op(var, (val), -=)
227#endif
228
229#ifndef percpu_and
230# define percpu_and(var, val) __percpu_generic_to_op(var, (val), &=)
231#endif
232
233#ifndef percpu_or
234# define percpu_or(var, val) __percpu_generic_to_op(var, (val), |=)
235#endif
236
237#ifndef percpu_xor
238# define percpu_xor(var, val) __percpu_generic_to_op(var, (val), ^=)
239#endif
240
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900241/*
242 * Branching function to split up a function into a set of functions that
243 * are called for different scalar sizes of the objects handled.
244 */
245
246extern void __bad_size_call_parameter(void);
247
Tejun Heo0f5e4812009-10-29 22:34:12 +0900248#define __pcpu_size_call_return(stem, variable) \
249({ typeof(variable) pscr_ret__; \
Tejun Heo545695f2009-10-29 22:34:15 +0900250 __verify_pcpu_ptr(&(variable)); \
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900251 switch(sizeof(variable)) { \
Tejun Heo0f5e4812009-10-29 22:34:12 +0900252 case 1: pscr_ret__ = stem##1(variable);break; \
253 case 2: pscr_ret__ = stem##2(variable);break; \
254 case 4: pscr_ret__ = stem##4(variable);break; \
255 case 8: pscr_ret__ = stem##8(variable);break; \
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900256 default: \
257 __bad_size_call_parameter();break; \
258 } \
Tejun Heo0f5e4812009-10-29 22:34:12 +0900259 pscr_ret__; \
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900260})
261
Tejun Heo0f5e4812009-10-29 22:34:12 +0900262#define __pcpu_size_call(stem, variable, ...) \
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900263do { \
Tejun Heo545695f2009-10-29 22:34:15 +0900264 __verify_pcpu_ptr(&(variable)); \
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900265 switch(sizeof(variable)) { \
266 case 1: stem##1(variable, __VA_ARGS__);break; \
267 case 2: stem##2(variable, __VA_ARGS__);break; \
268 case 4: stem##4(variable, __VA_ARGS__);break; \
269 case 8: stem##8(variable, __VA_ARGS__);break; \
270 default: \
271 __bad_size_call_parameter();break; \
272 } \
273} while (0)
274
275/*
276 * Optimized manipulation for memory allocated through the per cpu
Rusty Russelldd17c8f2009-10-29 22:34:15 +0900277 * allocator or for addresses of per cpu variables.
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900278 *
279 * These operation guarantee exclusivity of access for other operations
280 * on the *same* processor. The assumption is that per cpu data is only
281 * accessed by a single processor instance (the current one).
282 *
283 * The first group is used for accesses that must be done in a
284 * preemption safe way since we know that the context is not preempt
285 * safe. Interrupts may occur. If the interrupt modifies the variable
286 * too then RMW actions will not be reliable.
287 *
288 * The arch code can provide optimized functions in two ways:
289 *
290 * 1. Override the function completely. F.e. define this_cpu_add().
291 * The arch must then ensure that the various scalar format passed
292 * are handled correctly.
293 *
294 * 2. Provide functions for certain scalar sizes. F.e. provide
295 * this_cpu_add_2() to provide per cpu atomic operations for 2 byte
296 * sized RMW actions. If arch code does not provide operations for
297 * a scalar size then the fallback in the generic code will be
298 * used.
299 */
300
301#define _this_cpu_generic_read(pcp) \
302({ typeof(pcp) ret__; \
303 preempt_disable(); \
304 ret__ = *this_cpu_ptr(&(pcp)); \
305 preempt_enable(); \
306 ret__; \
307})
308
309#ifndef this_cpu_read
310# ifndef this_cpu_read_1
311# define this_cpu_read_1(pcp) _this_cpu_generic_read(pcp)
312# endif
313# ifndef this_cpu_read_2
314# define this_cpu_read_2(pcp) _this_cpu_generic_read(pcp)
315# endif
316# ifndef this_cpu_read_4
317# define this_cpu_read_4(pcp) _this_cpu_generic_read(pcp)
318# endif
319# ifndef this_cpu_read_8
320# define this_cpu_read_8(pcp) _this_cpu_generic_read(pcp)
321# endif
Tejun Heo0f5e4812009-10-29 22:34:12 +0900322# define this_cpu_read(pcp) __pcpu_size_call_return(this_cpu_read_, (pcp))
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900323#endif
324
325#define _this_cpu_generic_to_op(pcp, val, op) \
326do { \
327 preempt_disable(); \
Tejun Heof7b64fe2009-10-29 22:34:15 +0900328 *__this_cpu_ptr(&(pcp)) op val; \
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900329 preempt_enable(); \
330} while (0)
331
332#ifndef this_cpu_write
333# ifndef this_cpu_write_1
334# define this_cpu_write_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), =)
335# endif
336# ifndef this_cpu_write_2
337# define this_cpu_write_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), =)
338# endif
339# ifndef this_cpu_write_4
340# define this_cpu_write_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), =)
341# endif
342# ifndef this_cpu_write_8
343# define this_cpu_write_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), =)
344# endif
Tejun Heo0f5e4812009-10-29 22:34:12 +0900345# define this_cpu_write(pcp, val) __pcpu_size_call(this_cpu_write_, (pcp), (val))
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900346#endif
347
348#ifndef this_cpu_add
349# ifndef this_cpu_add_1
350# define this_cpu_add_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=)
351# endif
352# ifndef this_cpu_add_2
353# define this_cpu_add_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=)
354# endif
355# ifndef this_cpu_add_4
356# define this_cpu_add_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=)
357# endif
358# ifndef this_cpu_add_8
359# define this_cpu_add_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=)
360# endif
Tejun Heo0f5e4812009-10-29 22:34:12 +0900361# define this_cpu_add(pcp, val) __pcpu_size_call(this_cpu_add_, (pcp), (val))
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900362#endif
363
364#ifndef this_cpu_sub
365# define this_cpu_sub(pcp, val) this_cpu_add((pcp), -(val))
366#endif
367
368#ifndef this_cpu_inc
369# define this_cpu_inc(pcp) this_cpu_add((pcp), 1)
370#endif
371
372#ifndef this_cpu_dec
373# define this_cpu_dec(pcp) this_cpu_sub((pcp), 1)
374#endif
375
376#ifndef this_cpu_and
377# ifndef this_cpu_and_1
378# define this_cpu_and_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=)
379# endif
380# ifndef this_cpu_and_2
381# define this_cpu_and_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=)
382# endif
383# ifndef this_cpu_and_4
384# define this_cpu_and_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=)
385# endif
386# ifndef this_cpu_and_8
387# define this_cpu_and_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=)
388# endif
Tejun Heo0f5e4812009-10-29 22:34:12 +0900389# define this_cpu_and(pcp, val) __pcpu_size_call(this_cpu_and_, (pcp), (val))
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900390#endif
391
392#ifndef this_cpu_or
393# ifndef this_cpu_or_1
394# define this_cpu_or_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=)
395# endif
396# ifndef this_cpu_or_2
397# define this_cpu_or_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=)
398# endif
399# ifndef this_cpu_or_4
400# define this_cpu_or_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=)
401# endif
402# ifndef this_cpu_or_8
403# define this_cpu_or_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=)
404# endif
Tejun Heo0f5e4812009-10-29 22:34:12 +0900405# define this_cpu_or(pcp, val) __pcpu_size_call(this_cpu_or_, (pcp), (val))
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900406#endif
407
408#ifndef this_cpu_xor
409# ifndef this_cpu_xor_1
410# define this_cpu_xor_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=)
411# endif
412# ifndef this_cpu_xor_2
413# define this_cpu_xor_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=)
414# endif
415# ifndef this_cpu_xor_4
416# define this_cpu_xor_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=)
417# endif
418# ifndef this_cpu_xor_8
419# define this_cpu_xor_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=)
420# endif
Tejun Heo0f5e4812009-10-29 22:34:12 +0900421# define this_cpu_xor(pcp, val) __pcpu_size_call(this_cpu_or_, (pcp), (val))
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900422#endif
423
424/*
425 * Generic percpu operations that do not require preemption handling.
426 * Either we do not care about races or the caller has the
427 * responsibility of handling preemptions issues. Arch code can still
428 * override these instructions since the arch per cpu code may be more
429 * efficient and may actually get race freeness for free (that is the
430 * case for x86 for example).
431 *
432 * If there is no other protection through preempt disable and/or
433 * disabling interupts then one of these RMW operations can show unexpected
434 * behavior because the execution thread was rescheduled on another processor
435 * or an interrupt occurred and the same percpu variable was modified from
436 * the interrupt context.
437 */
438#ifndef __this_cpu_read
439# ifndef __this_cpu_read_1
440# define __this_cpu_read_1(pcp) (*__this_cpu_ptr(&(pcp)))
441# endif
442# ifndef __this_cpu_read_2
443# define __this_cpu_read_2(pcp) (*__this_cpu_ptr(&(pcp)))
444# endif
445# ifndef __this_cpu_read_4
446# define __this_cpu_read_4(pcp) (*__this_cpu_ptr(&(pcp)))
447# endif
448# ifndef __this_cpu_read_8
449# define __this_cpu_read_8(pcp) (*__this_cpu_ptr(&(pcp)))
450# endif
Tejun Heo0f5e4812009-10-29 22:34:12 +0900451# define __this_cpu_read(pcp) __pcpu_size_call_return(__this_cpu_read_, (pcp))
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900452#endif
453
454#define __this_cpu_generic_to_op(pcp, val, op) \
455do { \
456 *__this_cpu_ptr(&(pcp)) op val; \
457} while (0)
458
459#ifndef __this_cpu_write
460# ifndef __this_cpu_write_1
461# define __this_cpu_write_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), =)
462# endif
463# ifndef __this_cpu_write_2
464# define __this_cpu_write_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), =)
465# endif
466# ifndef __this_cpu_write_4
467# define __this_cpu_write_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), =)
468# endif
469# ifndef __this_cpu_write_8
470# define __this_cpu_write_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), =)
471# endif
Tejun Heo0f5e4812009-10-29 22:34:12 +0900472# define __this_cpu_write(pcp, val) __pcpu_size_call(__this_cpu_write_, (pcp), (val))
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900473#endif
474
475#ifndef __this_cpu_add
476# ifndef __this_cpu_add_1
477# define __this_cpu_add_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=)
478# endif
479# ifndef __this_cpu_add_2
480# define __this_cpu_add_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=)
481# endif
482# ifndef __this_cpu_add_4
483# define __this_cpu_add_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=)
484# endif
485# ifndef __this_cpu_add_8
486# define __this_cpu_add_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=)
487# endif
Tejun Heo0f5e4812009-10-29 22:34:12 +0900488# define __this_cpu_add(pcp, val) __pcpu_size_call(__this_cpu_add_, (pcp), (val))
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900489#endif
490
491#ifndef __this_cpu_sub
492# define __this_cpu_sub(pcp, val) __this_cpu_add((pcp), -(val))
493#endif
494
495#ifndef __this_cpu_inc
496# define __this_cpu_inc(pcp) __this_cpu_add((pcp), 1)
497#endif
498
499#ifndef __this_cpu_dec
500# define __this_cpu_dec(pcp) __this_cpu_sub((pcp), 1)
501#endif
502
503#ifndef __this_cpu_and
504# ifndef __this_cpu_and_1
505# define __this_cpu_and_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=)
506# endif
507# ifndef __this_cpu_and_2
508# define __this_cpu_and_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=)
509# endif
510# ifndef __this_cpu_and_4
511# define __this_cpu_and_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=)
512# endif
513# ifndef __this_cpu_and_8
514# define __this_cpu_and_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=)
515# endif
Tejun Heo0f5e4812009-10-29 22:34:12 +0900516# define __this_cpu_and(pcp, val) __pcpu_size_call(__this_cpu_and_, (pcp), (val))
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900517#endif
518
519#ifndef __this_cpu_or
520# ifndef __this_cpu_or_1
521# define __this_cpu_or_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=)
522# endif
523# ifndef __this_cpu_or_2
524# define __this_cpu_or_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=)
525# endif
526# ifndef __this_cpu_or_4
527# define __this_cpu_or_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=)
528# endif
529# ifndef __this_cpu_or_8
530# define __this_cpu_or_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=)
531# endif
Tejun Heo0f5e4812009-10-29 22:34:12 +0900532# define __this_cpu_or(pcp, val) __pcpu_size_call(__this_cpu_or_, (pcp), (val))
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900533#endif
534
535#ifndef __this_cpu_xor
536# ifndef __this_cpu_xor_1
537# define __this_cpu_xor_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=)
538# endif
539# ifndef __this_cpu_xor_2
540# define __this_cpu_xor_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=)
541# endif
542# ifndef __this_cpu_xor_4
543# define __this_cpu_xor_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=)
544# endif
545# ifndef __this_cpu_xor_8
546# define __this_cpu_xor_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=)
547# endif
Tejun Heo0f5e4812009-10-29 22:34:12 +0900548# define __this_cpu_xor(pcp, val) __pcpu_size_call(__this_cpu_xor_, (pcp), (val))
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900549#endif
550
551/*
552 * IRQ safe versions of the per cpu RMW operations. Note that these operations
553 * are *not* safe against modification of the same variable from another
554 * processors (which one gets when using regular atomic operations)
555 . They are guaranteed to be atomic vs. local interrupts and
556 * preemption only.
557 */
558#define irqsafe_cpu_generic_to_op(pcp, val, op) \
559do { \
560 unsigned long flags; \
561 local_irq_save(flags); \
562 *__this_cpu_ptr(&(pcp)) op val; \
563 local_irq_restore(flags); \
564} while (0)
565
566#ifndef irqsafe_cpu_add
567# ifndef irqsafe_cpu_add_1
568# define irqsafe_cpu_add_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
569# endif
570# ifndef irqsafe_cpu_add_2
571# define irqsafe_cpu_add_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
572# endif
573# ifndef irqsafe_cpu_add_4
574# define irqsafe_cpu_add_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
575# endif
576# ifndef irqsafe_cpu_add_8
577# define irqsafe_cpu_add_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
578# endif
Tejun Heo0f5e4812009-10-29 22:34:12 +0900579# define irqsafe_cpu_add(pcp, val) __pcpu_size_call(irqsafe_cpu_add_, (pcp), (val))
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900580#endif
581
582#ifndef irqsafe_cpu_sub
583# define irqsafe_cpu_sub(pcp, val) irqsafe_cpu_add((pcp), -(val))
584#endif
585
586#ifndef irqsafe_cpu_inc
587# define irqsafe_cpu_inc(pcp) irqsafe_cpu_add((pcp), 1)
588#endif
589
590#ifndef irqsafe_cpu_dec
591# define irqsafe_cpu_dec(pcp) irqsafe_cpu_sub((pcp), 1)
592#endif
593
594#ifndef irqsafe_cpu_and
595# ifndef irqsafe_cpu_and_1
596# define irqsafe_cpu_and_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
597# endif
598# ifndef irqsafe_cpu_and_2
599# define irqsafe_cpu_and_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
600# endif
601# ifndef irqsafe_cpu_and_4
602# define irqsafe_cpu_and_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
603# endif
604# ifndef irqsafe_cpu_and_8
605# define irqsafe_cpu_and_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
606# endif
Tejun Heo0f5e4812009-10-29 22:34:12 +0900607# define irqsafe_cpu_and(pcp, val) __pcpu_size_call(irqsafe_cpu_and_, (val))
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900608#endif
609
610#ifndef irqsafe_cpu_or
611# ifndef irqsafe_cpu_or_1
612# define irqsafe_cpu_or_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
613# endif
614# ifndef irqsafe_cpu_or_2
615# define irqsafe_cpu_or_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
616# endif
617# ifndef irqsafe_cpu_or_4
618# define irqsafe_cpu_or_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
619# endif
620# ifndef irqsafe_cpu_or_8
621# define irqsafe_cpu_or_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
622# endif
Tejun Heo0f5e4812009-10-29 22:34:12 +0900623# define irqsafe_cpu_or(pcp, val) __pcpu_size_call(irqsafe_cpu_or_, (val))
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900624#endif
625
626#ifndef irqsafe_cpu_xor
627# ifndef irqsafe_cpu_xor_1
628# define irqsafe_cpu_xor_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
629# endif
630# ifndef irqsafe_cpu_xor_2
631# define irqsafe_cpu_xor_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
632# endif
633# ifndef irqsafe_cpu_xor_4
634# define irqsafe_cpu_xor_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
635# endif
636# ifndef irqsafe_cpu_xor_8
637# define irqsafe_cpu_xor_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
638# endif
Tejun Heo0f5e4812009-10-29 22:34:12 +0900639# define irqsafe_cpu_xor(pcp, val) __pcpu_size_call(irqsafe_cpu_xor_, (val))
Christoph Lameter7340a0b2009-10-03 19:48:22 +0900640#endif
641
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642#endif /* __LINUX_PERCPU_H */