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62fde541 TH |
1 | /* |
2 | * linux/percpu-defs.h - basic definitions for percpu areas | |
3 | * | |
4 | * DO NOT INCLUDE DIRECTLY OUTSIDE PERCPU IMPLEMENTATION PROPER. | |
5 | * | |
6 | * This file is separate from linux/percpu.h to avoid cyclic inclusion | |
7 | * dependency from arch header files. Only to be included from | |
8 | * asm/percpu.h. | |
9 | * | |
10 | * This file includes macros necessary to declare percpu sections and | |
11 | * variables, and definitions of percpu accessors and operations. It | |
12 | * should provide enough percpu features to arch header files even when | |
13 | * they can only include asm/percpu.h to avoid cyclic inclusion dependency. | |
14 | */ | |
15 | ||
5028eaa9 DH |
16 | #ifndef _LINUX_PERCPU_DEFS_H |
17 | #define _LINUX_PERCPU_DEFS_H | |
18 | ||
62fde541 TH |
19 | #ifdef CONFIG_SMP |
20 | ||
21 | #ifdef MODULE | |
22 | #define PER_CPU_SHARED_ALIGNED_SECTION "" | |
23 | #define PER_CPU_ALIGNED_SECTION "" | |
24 | #else | |
25 | #define PER_CPU_SHARED_ALIGNED_SECTION "..shared_aligned" | |
26 | #define PER_CPU_ALIGNED_SECTION "..shared_aligned" | |
27 | #endif | |
28 | #define PER_CPU_FIRST_SECTION "..first" | |
29 | ||
30 | #else | |
31 | ||
32 | #define PER_CPU_SHARED_ALIGNED_SECTION "" | |
33 | #define PER_CPU_ALIGNED_SECTION "..shared_aligned" | |
34 | #define PER_CPU_FIRST_SECTION "" | |
35 | ||
36 | #endif | |
37 | ||
5028eaa9 DH |
38 | /* |
39 | * Base implementations of per-CPU variable declarations and definitions, where | |
40 | * the section in which the variable is to be placed is provided by the | |
7c756e6e | 41 | * 'sec' argument. This may be used to affect the parameters governing the |
5028eaa9 DH |
42 | * variable's storage. |
43 | * | |
44 | * NOTE! The sections for the DECLARE and for the DEFINE must match, lest | |
45 | * linkage errors occur due the compiler generating the wrong code to access | |
46 | * that section. | |
47 | */ | |
7c756e6e | 48 | #define __PCPU_ATTRS(sec) \ |
e0fdb0e0 | 49 | __percpu __attribute__((section(PER_CPU_BASE_SECTION sec))) \ |
7c756e6e TH |
50 | PER_CPU_ATTRIBUTES |
51 | ||
52 | #define __PCPU_DUMMY_ATTRS \ | |
53 | __attribute__((section(".discard"), unused)) | |
54 | ||
545695fb TH |
55 | /* |
56 | * Macro which verifies @ptr is a percpu pointer without evaluating | |
57 | * @ptr. This is to be used in percpu accessors to verify that the | |
58 | * input parameter is a percpu pointer. | |
abec1a80 CL |
59 | * |
60 | * + 0 is required in order to convert the pointer type from a | |
61 | * potential array type to a pointer to a single item of the array. | |
545695fb TH |
62 | */ |
63 | #define __verify_pcpu_ptr(ptr) do { \ | |
abec1a80 | 64 | const void __percpu *__vpp_verify = (typeof((ptr) + 0))NULL; \ |
545695fb TH |
65 | (void)__vpp_verify; \ |
66 | } while (0) | |
67 | ||
7c756e6e TH |
68 | /* |
69 | * s390 and alpha modules require percpu variables to be defined as | |
70 | * weak to force the compiler to generate GOT based external | |
71 | * references for them. This is necessary because percpu sections | |
72 | * will be located outside of the usually addressable area. | |
73 | * | |
74 | * This definition puts the following two extra restrictions when | |
75 | * defining percpu variables. | |
76 | * | |
77 | * 1. The symbol must be globally unique, even the static ones. | |
78 | * 2. Static percpu variables cannot be defined inside a function. | |
79 | * | |
80 | * Archs which need weak percpu definitions should define | |
81 | * ARCH_NEEDS_WEAK_PER_CPU in asm/percpu.h when necessary. | |
82 | * | |
83 | * To ensure that the generic code observes the above two | |
84 | * restrictions, if CONFIG_DEBUG_FORCE_WEAK_PER_CPU is set weak | |
85 | * definition is used for all cases. | |
86 | */ | |
87 | #if defined(ARCH_NEEDS_WEAK_PER_CPU) || defined(CONFIG_DEBUG_FORCE_WEAK_PER_CPU) | |
88 | /* | |
89 | * __pcpu_scope_* dummy variable is used to enforce scope. It | |
90 | * receives the static modifier when it's used in front of | |
91 | * DEFINE_PER_CPU() and will trigger build failure if | |
92 | * DECLARE_PER_CPU() is used for the same variable. | |
93 | * | |
94 | * __pcpu_unique_* dummy variable is used to enforce symbol uniqueness | |
95 | * such that hidden weak symbol collision, which will cause unrelated | |
96 | * variables to share the same address, can be detected during build. | |
97 | */ | |
98 | #define DECLARE_PER_CPU_SECTION(type, name, sec) \ | |
99 | extern __PCPU_DUMMY_ATTRS char __pcpu_scope_##name; \ | |
dd17c8f7 | 100 | extern __PCPU_ATTRS(sec) __typeof__(type) name |
7c756e6e TH |
101 | |
102 | #define DEFINE_PER_CPU_SECTION(type, name, sec) \ | |
103 | __PCPU_DUMMY_ATTRS char __pcpu_scope_##name; \ | |
0f5e4816 | 104 | extern __PCPU_DUMMY_ATTRS char __pcpu_unique_##name; \ |
7c756e6e | 105 | __PCPU_DUMMY_ATTRS char __pcpu_unique_##name; \ |
b1a0fbfd | 106 | extern __PCPU_ATTRS(sec) __typeof__(type) name; \ |
c43768cb | 107 | __PCPU_ATTRS(sec) PER_CPU_DEF_ATTRIBUTES __weak \ |
dd17c8f7 | 108 | __typeof__(type) name |
7c756e6e TH |
109 | #else |
110 | /* | |
111 | * Normal declaration and definition macros. | |
112 | */ | |
113 | #define DECLARE_PER_CPU_SECTION(type, name, sec) \ | |
dd17c8f7 | 114 | extern __PCPU_ATTRS(sec) __typeof__(type) name |
7c756e6e TH |
115 | |
116 | #define DEFINE_PER_CPU_SECTION(type, name, sec) \ | |
c43768cb | 117 | __PCPU_ATTRS(sec) PER_CPU_DEF_ATTRIBUTES \ |
dd17c8f7 | 118 | __typeof__(type) name |
7c756e6e | 119 | #endif |
5028eaa9 DH |
120 | |
121 | /* | |
122 | * Variant on the per-CPU variable declaration/definition theme used for | |
123 | * ordinary per-CPU variables. | |
124 | */ | |
125 | #define DECLARE_PER_CPU(type, name) \ | |
126 | DECLARE_PER_CPU_SECTION(type, name, "") | |
127 | ||
128 | #define DEFINE_PER_CPU(type, name) \ | |
129 | DEFINE_PER_CPU_SECTION(type, name, "") | |
130 | ||
131 | /* | |
132 | * Declaration/definition used for per-CPU variables that must come first in | |
133 | * the set of variables. | |
134 | */ | |
135 | #define DECLARE_PER_CPU_FIRST(type, name) \ | |
136 | DECLARE_PER_CPU_SECTION(type, name, PER_CPU_FIRST_SECTION) | |
137 | ||
138 | #define DEFINE_PER_CPU_FIRST(type, name) \ | |
139 | DEFINE_PER_CPU_SECTION(type, name, PER_CPU_FIRST_SECTION) | |
140 | ||
141 | /* | |
142 | * Declaration/definition used for per-CPU variables that must be cacheline | |
143 | * aligned under SMP conditions so that, whilst a particular instance of the | |
144 | * data corresponds to a particular CPU, inefficiencies due to direct access by | |
145 | * other CPUs are reduced by preventing the data from unnecessarily spanning | |
146 | * cachelines. | |
147 | * | |
148 | * An example of this would be statistical data, where each CPU's set of data | |
149 | * is updated by that CPU alone, but the data from across all CPUs is collated | |
150 | * by a CPU processing a read from a proc file. | |
151 | */ | |
152 | #define DECLARE_PER_CPU_SHARED_ALIGNED(type, name) \ | |
153 | DECLARE_PER_CPU_SECTION(type, name, PER_CPU_SHARED_ALIGNED_SECTION) \ | |
154 | ____cacheline_aligned_in_smp | |
155 | ||
156 | #define DEFINE_PER_CPU_SHARED_ALIGNED(type, name) \ | |
157 | DEFINE_PER_CPU_SECTION(type, name, PER_CPU_SHARED_ALIGNED_SECTION) \ | |
158 | ____cacheline_aligned_in_smp | |
159 | ||
53f82452 JF |
160 | #define DECLARE_PER_CPU_ALIGNED(type, name) \ |
161 | DECLARE_PER_CPU_SECTION(type, name, PER_CPU_ALIGNED_SECTION) \ | |
162 | ____cacheline_aligned | |
163 | ||
164 | #define DEFINE_PER_CPU_ALIGNED(type, name) \ | |
165 | DEFINE_PER_CPU_SECTION(type, name, PER_CPU_ALIGNED_SECTION) \ | |
166 | ____cacheline_aligned | |
167 | ||
5028eaa9 DH |
168 | /* |
169 | * Declaration/definition used for per-CPU variables that must be page aligned. | |
170 | */ | |
3e352aa8 | 171 | #define DECLARE_PER_CPU_PAGE_ALIGNED(type, name) \ |
3d9a854c | 172 | DECLARE_PER_CPU_SECTION(type, name, "..page_aligned") \ |
3e352aa8 | 173 | __aligned(PAGE_SIZE) |
5028eaa9 DH |
174 | |
175 | #define DEFINE_PER_CPU_PAGE_ALIGNED(type, name) \ | |
3d9a854c | 176 | DEFINE_PER_CPU_SECTION(type, name, "..page_aligned") \ |
3e352aa8 | 177 | __aligned(PAGE_SIZE) |
5028eaa9 | 178 | |
c957ef2c SL |
179 | /* |
180 | * Declaration/definition used for per-CPU variables that must be read mostly. | |
181 | */ | |
182 | #define DECLARE_PER_CPU_READ_MOSTLY(type, name) \ | |
183 | DECLARE_PER_CPU_SECTION(type, name, "..readmostly") | |
184 | ||
185 | #define DEFINE_PER_CPU_READ_MOSTLY(type, name) \ | |
186 | DEFINE_PER_CPU_SECTION(type, name, "..readmostly") | |
187 | ||
5028eaa9 | 188 | /* |
545695fb TH |
189 | * Intermodule exports for per-CPU variables. sparse forgets about |
190 | * address space across EXPORT_SYMBOL(), change EXPORT_SYMBOL() to | |
191 | * noop if __CHECKER__. | |
5028eaa9 | 192 | */ |
545695fb | 193 | #ifndef __CHECKER__ |
dd17c8f7 RR |
194 | #define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(var) |
195 | #define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(var) | |
545695fb TH |
196 | #else |
197 | #define EXPORT_PER_CPU_SYMBOL(var) | |
198 | #define EXPORT_PER_CPU_SYMBOL_GPL(var) | |
199 | #endif | |
5028eaa9 | 200 | |
62fde541 TH |
201 | /* |
202 | * Accessors and operations. | |
203 | */ | |
204 | #ifndef __ASSEMBLY__ | |
205 | ||
206 | #ifdef CONFIG_SMP | |
207 | ||
208 | /* | |
209 | * Add an offset to a pointer but keep the pointer as-is. Use RELOC_HIDE() | |
210 | * to prevent the compiler from making incorrect assumptions about the | |
211 | * pointer value. The weird cast keeps both GCC and sparse happy. | |
212 | */ | |
213 | #define SHIFT_PERCPU_PTR(__p, __offset) ({ \ | |
214 | __verify_pcpu_ptr((__p)); \ | |
215 | RELOC_HIDE((typeof(*(__p)) __kernel __force *)(__p), (__offset)); \ | |
216 | }) | |
217 | ||
3b8ed91d TH |
218 | #define per_cpu_ptr(ptr, cpu) SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu))) |
219 | #define raw_cpu_ptr(ptr) arch_raw_cpu_ptr(ptr) | |
62fde541 TH |
220 | |
221 | #ifdef CONFIG_DEBUG_PREEMPT | |
222 | #define this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, my_cpu_offset) | |
223 | #else | |
224 | #define this_cpu_ptr(ptr) raw_cpu_ptr(ptr) | |
225 | #endif | |
226 | ||
62fde541 TH |
227 | #else /* CONFIG_SMP */ |
228 | ||
229 | #define VERIFY_PERCPU_PTR(__p) ({ \ | |
230 | __verify_pcpu_ptr((__p)); \ | |
231 | (typeof(*(__p)) __kernel __force *)(__p); \ | |
232 | }) | |
233 | ||
3b8ed91d TH |
234 | #define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); VERIFY_PERCPU_PTR((ptr)); }) |
235 | #define raw_cpu_ptr(ptr) per_cpu_ptr(ptr, 0) | |
236 | #define this_cpu_ptr(ptr) raw_cpu_ptr(ptr) | |
62fde541 TH |
237 | |
238 | #endif /* CONFIG_SMP */ | |
239 | ||
3b8ed91d TH |
240 | #define per_cpu(var, cpu) (*per_cpu_ptr(&(var), cpu)) |
241 | #define __raw_get_cpu_var(var) (*raw_cpu_ptr(&(var))) | |
242 | #define __get_cpu_var(var) (*this_cpu_ptr(&(var))) | |
243 | ||
62fde541 TH |
244 | /* keep until we have removed all uses of __this_cpu_ptr */ |
245 | #define __this_cpu_ptr(ptr) raw_cpu_ptr(ptr) | |
246 | ||
9defda18 TH |
247 | /* |
248 | * Must be an lvalue. Since @var must be a simple identifier, | |
249 | * we force a syntax error here if it isn't. | |
250 | */ | |
251 | #define get_cpu_var(var) (*({ \ | |
252 | preempt_disable(); \ | |
253 | this_cpu_ptr(&var); })) | |
254 | ||
255 | /* | |
256 | * The weird & is necessary because sparse considers (void)(var) to be | |
257 | * a direct dereference of percpu variable (var). | |
258 | */ | |
259 | #define put_cpu_var(var) do { \ | |
260 | (void)&(var); \ | |
261 | preempt_enable(); \ | |
262 | } while (0) | |
263 | ||
264 | #define get_cpu_ptr(var) ({ \ | |
265 | preempt_disable(); \ | |
266 | this_cpu_ptr(var); }) | |
267 | ||
268 | #define put_cpu_ptr(var) do { \ | |
269 | (void)(var); \ | |
270 | preempt_enable(); \ | |
271 | } while (0) | |
272 | ||
a32f8d8e TH |
273 | /* |
274 | * Branching function to split up a function into a set of functions that | |
275 | * are called for different scalar sizes of the objects handled. | |
276 | */ | |
277 | ||
278 | extern void __bad_size_call_parameter(void); | |
279 | ||
280 | #ifdef CONFIG_DEBUG_PREEMPT | |
281 | extern void __this_cpu_preempt_check(const char *op); | |
282 | #else | |
283 | static inline void __this_cpu_preempt_check(const char *op) { } | |
284 | #endif | |
285 | ||
286 | #define __pcpu_size_call_return(stem, variable) \ | |
287 | ({ typeof(variable) pscr_ret__; \ | |
288 | __verify_pcpu_ptr(&(variable)); \ | |
289 | switch(sizeof(variable)) { \ | |
290 | case 1: pscr_ret__ = stem##1(variable);break; \ | |
291 | case 2: pscr_ret__ = stem##2(variable);break; \ | |
292 | case 4: pscr_ret__ = stem##4(variable);break; \ | |
293 | case 8: pscr_ret__ = stem##8(variable);break; \ | |
294 | default: \ | |
295 | __bad_size_call_parameter();break; \ | |
296 | } \ | |
297 | pscr_ret__; \ | |
298 | }) | |
299 | ||
300 | #define __pcpu_size_call_return2(stem, variable, ...) \ | |
301 | ({ \ | |
302 | typeof(variable) pscr2_ret__; \ | |
303 | __verify_pcpu_ptr(&(variable)); \ | |
304 | switch(sizeof(variable)) { \ | |
305 | case 1: pscr2_ret__ = stem##1(variable, __VA_ARGS__); break; \ | |
306 | case 2: pscr2_ret__ = stem##2(variable, __VA_ARGS__); break; \ | |
307 | case 4: pscr2_ret__ = stem##4(variable, __VA_ARGS__); break; \ | |
308 | case 8: pscr2_ret__ = stem##8(variable, __VA_ARGS__); break; \ | |
309 | default: \ | |
310 | __bad_size_call_parameter(); break; \ | |
311 | } \ | |
312 | pscr2_ret__; \ | |
313 | }) | |
314 | ||
315 | /* | |
316 | * Special handling for cmpxchg_double. cmpxchg_double is passed two | |
317 | * percpu variables. The first has to be aligned to a double word | |
318 | * boundary and the second has to follow directly thereafter. | |
319 | * We enforce this on all architectures even if they don't support | |
320 | * a double cmpxchg instruction, since it's a cheap requirement, and it | |
321 | * avoids breaking the requirement for architectures with the instruction. | |
322 | */ | |
323 | #define __pcpu_double_call_return_bool(stem, pcp1, pcp2, ...) \ | |
324 | ({ \ | |
325 | bool pdcrb_ret__; \ | |
326 | __verify_pcpu_ptr(&pcp1); \ | |
327 | BUILD_BUG_ON(sizeof(pcp1) != sizeof(pcp2)); \ | |
328 | VM_BUG_ON((unsigned long)(&pcp1) % (2 * sizeof(pcp1))); \ | |
329 | VM_BUG_ON((unsigned long)(&pcp2) != \ | |
330 | (unsigned long)(&pcp1) + sizeof(pcp1)); \ | |
331 | switch(sizeof(pcp1)) { \ | |
332 | case 1: pdcrb_ret__ = stem##1(pcp1, pcp2, __VA_ARGS__); break; \ | |
333 | case 2: pdcrb_ret__ = stem##2(pcp1, pcp2, __VA_ARGS__); break; \ | |
334 | case 4: pdcrb_ret__ = stem##4(pcp1, pcp2, __VA_ARGS__); break; \ | |
335 | case 8: pdcrb_ret__ = stem##8(pcp1, pcp2, __VA_ARGS__); break; \ | |
336 | default: \ | |
337 | __bad_size_call_parameter(); break; \ | |
338 | } \ | |
339 | pdcrb_ret__; \ | |
340 | }) | |
341 | ||
342 | #define __pcpu_size_call(stem, variable, ...) \ | |
343 | do { \ | |
344 | __verify_pcpu_ptr(&(variable)); \ | |
345 | switch(sizeof(variable)) { \ | |
346 | case 1: stem##1(variable, __VA_ARGS__);break; \ | |
347 | case 2: stem##2(variable, __VA_ARGS__);break; \ | |
348 | case 4: stem##4(variable, __VA_ARGS__);break; \ | |
349 | case 8: stem##8(variable, __VA_ARGS__);break; \ | |
350 | default: \ | |
351 | __bad_size_call_parameter();break; \ | |
352 | } \ | |
353 | } while (0) | |
354 | ||
355 | /* | |
356 | * this_cpu operations (C) 2008-2013 Christoph Lameter <cl@linux.com> | |
357 | * | |
358 | * Optimized manipulation for memory allocated through the per cpu | |
359 | * allocator or for addresses of per cpu variables. | |
360 | * | |
361 | * These operation guarantee exclusivity of access for other operations | |
362 | * on the *same* processor. The assumption is that per cpu data is only | |
363 | * accessed by a single processor instance (the current one). | |
364 | * | |
365 | * The arch code can provide optimized implementation by defining macros | |
366 | * for certain scalar sizes. F.e. provide this_cpu_add_2() to provide per | |
367 | * cpu atomic operations for 2 byte sized RMW actions. If arch code does | |
368 | * not provide operations for a scalar size then the fallback in the | |
369 | * generic code will be used. | |
370 | */ | |
371 | ||
372 | /* | |
373 | * Generic percpu operations for contexts where we do not want to do | |
374 | * any checks for preemptiosn. | |
375 | * | |
376 | * If there is no other protection through preempt disable and/or | |
377 | * disabling interupts then one of these RMW operations can show unexpected | |
378 | * behavior because the execution thread was rescheduled on another processor | |
379 | * or an interrupt occurred and the same percpu variable was modified from | |
380 | * the interrupt context. | |
381 | */ | |
382 | # define raw_cpu_read(pcp) __pcpu_size_call_return(raw_cpu_read_, (pcp)) | |
383 | # define raw_cpu_write(pcp, val) __pcpu_size_call(raw_cpu_write_, (pcp), (val)) | |
384 | # define raw_cpu_add(pcp, val) __pcpu_size_call(raw_cpu_add_, (pcp), (val)) | |
385 | # define raw_cpu_sub(pcp, val) raw_cpu_add((pcp), -(val)) | |
386 | # define raw_cpu_inc(pcp) raw_cpu_add((pcp), 1) | |
387 | # define raw_cpu_dec(pcp) raw_cpu_sub((pcp), 1) | |
388 | # define raw_cpu_and(pcp, val) __pcpu_size_call(raw_cpu_and_, (pcp), (val)) | |
389 | # define raw_cpu_or(pcp, val) __pcpu_size_call(raw_cpu_or_, (pcp), (val)) | |
390 | # define raw_cpu_add_return(pcp, val) \ | |
391 | __pcpu_size_call_return2(raw_cpu_add_return_, pcp, val) | |
392 | #define raw_cpu_sub_return(pcp, val) raw_cpu_add_return(pcp, -(typeof(pcp))(val)) | |
393 | #define raw_cpu_inc_return(pcp) raw_cpu_add_return(pcp, 1) | |
394 | #define raw_cpu_dec_return(pcp) raw_cpu_add_return(pcp, -1) | |
395 | # define raw_cpu_xchg(pcp, nval) \ | |
396 | __pcpu_size_call_return2(raw_cpu_xchg_, (pcp), nval) | |
397 | # define raw_cpu_cmpxchg(pcp, oval, nval) \ | |
398 | __pcpu_size_call_return2(raw_cpu_cmpxchg_, pcp, oval, nval) | |
399 | # define raw_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \ | |
400 | __pcpu_double_call_return_bool(raw_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2)) | |
401 | ||
402 | /* | |
403 | * Generic percpu operations for context that are safe from preemption/interrupts. | |
404 | */ | |
405 | # define __this_cpu_read(pcp) \ | |
406 | (__this_cpu_preempt_check("read"),__pcpu_size_call_return(raw_cpu_read_, (pcp))) | |
407 | ||
408 | # define __this_cpu_write(pcp, val) \ | |
409 | do { __this_cpu_preempt_check("write"); \ | |
410 | __pcpu_size_call(raw_cpu_write_, (pcp), (val)); \ | |
411 | } while (0) | |
412 | ||
413 | # define __this_cpu_add(pcp, val) \ | |
414 | do { __this_cpu_preempt_check("add"); \ | |
415 | __pcpu_size_call(raw_cpu_add_, (pcp), (val)); \ | |
416 | } while (0) | |
417 | ||
418 | # define __this_cpu_sub(pcp, val) __this_cpu_add((pcp), -(typeof(pcp))(val)) | |
419 | # define __this_cpu_inc(pcp) __this_cpu_add((pcp), 1) | |
420 | # define __this_cpu_dec(pcp) __this_cpu_sub((pcp), 1) | |
421 | ||
422 | # define __this_cpu_and(pcp, val) \ | |
423 | do { __this_cpu_preempt_check("and"); \ | |
424 | __pcpu_size_call(raw_cpu_and_, (pcp), (val)); \ | |
425 | } while (0) | |
426 | ||
427 | # define __this_cpu_or(pcp, val) \ | |
428 | do { __this_cpu_preempt_check("or"); \ | |
429 | __pcpu_size_call(raw_cpu_or_, (pcp), (val)); \ | |
430 | } while (0) | |
431 | ||
432 | # define __this_cpu_add_return(pcp, val) \ | |
433 | (__this_cpu_preempt_check("add_return"),__pcpu_size_call_return2(raw_cpu_add_return_, pcp, val)) | |
434 | ||
435 | #define __this_cpu_sub_return(pcp, val) __this_cpu_add_return(pcp, -(typeof(pcp))(val)) | |
436 | #define __this_cpu_inc_return(pcp) __this_cpu_add_return(pcp, 1) | |
437 | #define __this_cpu_dec_return(pcp) __this_cpu_add_return(pcp, -1) | |
438 | ||
439 | # define __this_cpu_xchg(pcp, nval) \ | |
440 | (__this_cpu_preempt_check("xchg"),__pcpu_size_call_return2(raw_cpu_xchg_, (pcp), nval)) | |
441 | ||
442 | # define __this_cpu_cmpxchg(pcp, oval, nval) \ | |
443 | (__this_cpu_preempt_check("cmpxchg"),__pcpu_size_call_return2(raw_cpu_cmpxchg_, pcp, oval, nval)) | |
444 | ||
445 | # define __this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \ | |
446 | (__this_cpu_preempt_check("cmpxchg_double"),__pcpu_double_call_return_bool(raw_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))) | |
447 | ||
448 | /* | |
449 | * this_cpu_*() operations are used for accesses that must be done in a | |
450 | * preemption safe way since we know that the context is not preempt | |
451 | * safe. Interrupts may occur. If the interrupt modifies the variable too | |
452 | * then RMW actions will not be reliable. | |
453 | */ | |
454 | # define this_cpu_read(pcp) __pcpu_size_call_return(this_cpu_read_, (pcp)) | |
455 | # define this_cpu_write(pcp, val) __pcpu_size_call(this_cpu_write_, (pcp), (val)) | |
456 | # define this_cpu_add(pcp, val) __pcpu_size_call(this_cpu_add_, (pcp), (val)) | |
457 | # define this_cpu_sub(pcp, val) this_cpu_add((pcp), -(typeof(pcp))(val)) | |
458 | # define this_cpu_inc(pcp) this_cpu_add((pcp), 1) | |
459 | # define this_cpu_dec(pcp) this_cpu_sub((pcp), 1) | |
460 | # define this_cpu_and(pcp, val) __pcpu_size_call(this_cpu_and_, (pcp), (val)) | |
461 | # define this_cpu_or(pcp, val) __pcpu_size_call(this_cpu_or_, (pcp), (val)) | |
462 | # define this_cpu_add_return(pcp, val) __pcpu_size_call_return2(this_cpu_add_return_, pcp, val) | |
463 | #define this_cpu_sub_return(pcp, val) this_cpu_add_return(pcp, -(typeof(pcp))(val)) | |
464 | #define this_cpu_inc_return(pcp) this_cpu_add_return(pcp, 1) | |
465 | #define this_cpu_dec_return(pcp) this_cpu_add_return(pcp, -1) | |
466 | # define this_cpu_xchg(pcp, nval) \ | |
467 | __pcpu_size_call_return2(this_cpu_xchg_, (pcp), nval) | |
468 | # define this_cpu_cmpxchg(pcp, oval, nval) \ | |
469 | __pcpu_size_call_return2(this_cpu_cmpxchg_, pcp, oval, nval) | |
470 | ||
471 | /* | |
472 | * cmpxchg_double replaces two adjacent scalars at once. The first | |
473 | * two parameters are per cpu variables which have to be of the same | |
474 | * size. A truth value is returned to indicate success or failure | |
475 | * (since a double register result is difficult to handle). There is | |
476 | * very limited hardware support for these operations, so only certain | |
477 | * sizes may work. | |
478 | */ | |
479 | # define this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \ | |
480 | __pcpu_double_call_return_bool(this_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2)) | |
481 | ||
62fde541 | 482 | #endif /* __ASSEMBLY__ */ |
5028eaa9 | 483 | #endif /* _LINUX_PERCPU_DEFS_H */ |