xref: /linux/arch/x86/include/asm/percpu.h (revision a8b70ccf10e38775785d9cb12ead916474549f99)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_PERCPU_H
3 #define _ASM_X86_PERCPU_H
4 
5 #ifdef CONFIG_X86_64
6 #define __percpu_seg		gs
7 #define __percpu_mov_op		movq
8 #else
9 #define __percpu_seg		fs
10 #define __percpu_mov_op		movl
11 #endif
12 
13 #ifdef __ASSEMBLY__
14 
15 /*
16  * PER_CPU finds an address of a per-cpu variable.
17  *
18  * Args:
19  *    var - variable name
20  *    reg - 32bit register
21  *
22  * The resulting address is stored in the "reg" argument.
23  *
24  * Example:
25  *    PER_CPU(cpu_gdt_descr, %ebx)
26  */
27 #ifdef CONFIG_SMP
28 #define PER_CPU(var, reg)						\
29 	__percpu_mov_op %__percpu_seg:this_cpu_off, reg;		\
30 	lea var(reg), reg
31 #define PER_CPU_VAR(var)	%__percpu_seg:var
32 #else /* ! SMP */
33 #define PER_CPU(var, reg)	__percpu_mov_op $var, reg
34 #define PER_CPU_VAR(var)	var
35 #endif	/* SMP */
36 
37 #ifdef CONFIG_X86_64_SMP
38 #define INIT_PER_CPU_VAR(var)  init_per_cpu__##var
39 #else
40 #define INIT_PER_CPU_VAR(var)  var
41 #endif
42 
43 #else /* ...!ASSEMBLY */
44 
45 #include <linux/kernel.h>
46 #include <linux/stringify.h>
47 
48 #ifdef CONFIG_SMP
49 #define __percpu_prefix		"%%"__stringify(__percpu_seg)":"
50 #define __my_cpu_offset		this_cpu_read(this_cpu_off)
51 
52 /*
53  * Compared to the generic __my_cpu_offset version, the following
54  * saves one instruction and avoids clobbering a temp register.
55  */
56 #define arch_raw_cpu_ptr(ptr)				\
57 ({							\
58 	unsigned long tcp_ptr__;			\
59 	asm volatile("add " __percpu_arg(1) ", %0"	\
60 		     : "=r" (tcp_ptr__)			\
61 		     : "m" (this_cpu_off), "0" (ptr));	\
62 	(typeof(*(ptr)) __kernel __force *)tcp_ptr__;	\
63 })
64 #else
65 #define __percpu_prefix		""
66 #endif
67 
68 #define __percpu_arg(x)		__percpu_prefix "%" #x
69 
70 /*
71  * Initialized pointers to per-cpu variables needed for the boot
72  * processor need to use these macros to get the proper address
73  * offset from __per_cpu_load on SMP.
74  *
75  * There also must be an entry in vmlinux_64.lds.S
76  */
77 #define DECLARE_INIT_PER_CPU(var) \
78        extern typeof(var) init_per_cpu_var(var)
79 
80 #ifdef CONFIG_X86_64_SMP
81 #define init_per_cpu_var(var)  init_per_cpu__##var
82 #else
83 #define init_per_cpu_var(var)  var
84 #endif
85 
86 /* For arch-specific code, we can use direct single-insn ops (they
87  * don't give an lvalue though). */
88 extern void __bad_percpu_size(void);
89 
90 #define percpu_to_op(op, var, val)			\
91 do {							\
92 	typedef typeof(var) pto_T__;			\
93 	if (0) {					\
94 		pto_T__ pto_tmp__;			\
95 		pto_tmp__ = (val);			\
96 		(void)pto_tmp__;			\
97 	}						\
98 	switch (sizeof(var)) {				\
99 	case 1:						\
100 		asm(op "b %1,"__percpu_arg(0)		\
101 		    : "+m" (var)			\
102 		    : "qi" ((pto_T__)(val)));		\
103 		break;					\
104 	case 2:						\
105 		asm(op "w %1,"__percpu_arg(0)		\
106 		    : "+m" (var)			\
107 		    : "ri" ((pto_T__)(val)));		\
108 		break;					\
109 	case 4:						\
110 		asm(op "l %1,"__percpu_arg(0)		\
111 		    : "+m" (var)			\
112 		    : "ri" ((pto_T__)(val)));		\
113 		break;					\
114 	case 8:						\
115 		asm(op "q %1,"__percpu_arg(0)		\
116 		    : "+m" (var)			\
117 		    : "re" ((pto_T__)(val)));		\
118 		break;					\
119 	default: __bad_percpu_size();			\
120 	}						\
121 } while (0)
122 
123 /*
124  * Generate a percpu add to memory instruction and optimize code
125  * if one is added or subtracted.
126  */
127 #define percpu_add_op(var, val)						\
128 do {									\
129 	typedef typeof(var) pao_T__;					\
130 	const int pao_ID__ = (__builtin_constant_p(val) &&		\
131 			      ((val) == 1 || (val) == -1)) ?		\
132 				(int)(val) : 0;				\
133 	if (0) {							\
134 		pao_T__ pao_tmp__;					\
135 		pao_tmp__ = (val);					\
136 		(void)pao_tmp__;					\
137 	}								\
138 	switch (sizeof(var)) {						\
139 	case 1:								\
140 		if (pao_ID__ == 1)					\
141 			asm("incb "__percpu_arg(0) : "+m" (var));	\
142 		else if (pao_ID__ == -1)				\
143 			asm("decb "__percpu_arg(0) : "+m" (var));	\
144 		else							\
145 			asm("addb %1, "__percpu_arg(0)			\
146 			    : "+m" (var)				\
147 			    : "qi" ((pao_T__)(val)));			\
148 		break;							\
149 	case 2:								\
150 		if (pao_ID__ == 1)					\
151 			asm("incw "__percpu_arg(0) : "+m" (var));	\
152 		else if (pao_ID__ == -1)				\
153 			asm("decw "__percpu_arg(0) : "+m" (var));	\
154 		else							\
155 			asm("addw %1, "__percpu_arg(0)			\
156 			    : "+m" (var)				\
157 			    : "ri" ((pao_T__)(val)));			\
158 		break;							\
159 	case 4:								\
160 		if (pao_ID__ == 1)					\
161 			asm("incl "__percpu_arg(0) : "+m" (var));	\
162 		else if (pao_ID__ == -1)				\
163 			asm("decl "__percpu_arg(0) : "+m" (var));	\
164 		else							\
165 			asm("addl %1, "__percpu_arg(0)			\
166 			    : "+m" (var)				\
167 			    : "ri" ((pao_T__)(val)));			\
168 		break;							\
169 	case 8:								\
170 		if (pao_ID__ == 1)					\
171 			asm("incq "__percpu_arg(0) : "+m" (var));	\
172 		else if (pao_ID__ == -1)				\
173 			asm("decq "__percpu_arg(0) : "+m" (var));	\
174 		else							\
175 			asm("addq %1, "__percpu_arg(0)			\
176 			    : "+m" (var)				\
177 			    : "re" ((pao_T__)(val)));			\
178 		break;							\
179 	default: __bad_percpu_size();					\
180 	}								\
181 } while (0)
182 
183 #define percpu_from_op(op, var)				\
184 ({							\
185 	typeof(var) pfo_ret__;				\
186 	switch (sizeof(var)) {				\
187 	case 1:						\
188 		asm(op "b "__percpu_arg(1)",%0"		\
189 		    : "=q" (pfo_ret__)			\
190 		    : "m" (var));			\
191 		break;					\
192 	case 2:						\
193 		asm(op "w "__percpu_arg(1)",%0"		\
194 		    : "=r" (pfo_ret__)			\
195 		    : "m" (var));			\
196 		break;					\
197 	case 4:						\
198 		asm(op "l "__percpu_arg(1)",%0"		\
199 		    : "=r" (pfo_ret__)			\
200 		    : "m" (var));			\
201 		break;					\
202 	case 8:						\
203 		asm(op "q "__percpu_arg(1)",%0"		\
204 		    : "=r" (pfo_ret__)			\
205 		    : "m" (var));			\
206 		break;					\
207 	default: __bad_percpu_size();			\
208 	}						\
209 	pfo_ret__;					\
210 })
211 
212 #define percpu_stable_op(op, var)			\
213 ({							\
214 	typeof(var) pfo_ret__;				\
215 	switch (sizeof(var)) {				\
216 	case 1:						\
217 		asm(op "b "__percpu_arg(P1)",%0"	\
218 		    : "=q" (pfo_ret__)			\
219 		    : "p" (&(var)));			\
220 		break;					\
221 	case 2:						\
222 		asm(op "w "__percpu_arg(P1)",%0"	\
223 		    : "=r" (pfo_ret__)			\
224 		    : "p" (&(var)));			\
225 		break;					\
226 	case 4:						\
227 		asm(op "l "__percpu_arg(P1)",%0"	\
228 		    : "=r" (pfo_ret__)			\
229 		    : "p" (&(var)));			\
230 		break;					\
231 	case 8:						\
232 		asm(op "q "__percpu_arg(P1)",%0"	\
233 		    : "=r" (pfo_ret__)			\
234 		    : "p" (&(var)));			\
235 		break;					\
236 	default: __bad_percpu_size();			\
237 	}						\
238 	pfo_ret__;					\
239 })
240 
241 #define percpu_unary_op(op, var)			\
242 ({							\
243 	switch (sizeof(var)) {				\
244 	case 1:						\
245 		asm(op "b "__percpu_arg(0)		\
246 		    : "+m" (var));			\
247 		break;					\
248 	case 2:						\
249 		asm(op "w "__percpu_arg(0)		\
250 		    : "+m" (var));			\
251 		break;					\
252 	case 4:						\
253 		asm(op "l "__percpu_arg(0)		\
254 		    : "+m" (var));			\
255 		break;					\
256 	case 8:						\
257 		asm(op "q "__percpu_arg(0)		\
258 		    : "+m" (var));			\
259 		break;					\
260 	default: __bad_percpu_size();			\
261 	}						\
262 })
263 
264 /*
265  * Add return operation
266  */
267 #define percpu_add_return_op(var, val)					\
268 ({									\
269 	typeof(var) paro_ret__ = val;					\
270 	switch (sizeof(var)) {						\
271 	case 1:								\
272 		asm("xaddb %0, "__percpu_arg(1)				\
273 			    : "+q" (paro_ret__), "+m" (var)		\
274 			    : : "memory");				\
275 		break;							\
276 	case 2:								\
277 		asm("xaddw %0, "__percpu_arg(1)				\
278 			    : "+r" (paro_ret__), "+m" (var)		\
279 			    : : "memory");				\
280 		break;							\
281 	case 4:								\
282 		asm("xaddl %0, "__percpu_arg(1)				\
283 			    : "+r" (paro_ret__), "+m" (var)		\
284 			    : : "memory");				\
285 		break;							\
286 	case 8:								\
287 		asm("xaddq %0, "__percpu_arg(1)				\
288 			    : "+re" (paro_ret__), "+m" (var)		\
289 			    : : "memory");				\
290 		break;							\
291 	default: __bad_percpu_size();					\
292 	}								\
293 	paro_ret__ += val;						\
294 	paro_ret__;							\
295 })
296 
297 /*
298  * xchg is implemented using cmpxchg without a lock prefix. xchg is
299  * expensive due to the implied lock prefix.  The processor cannot prefetch
300  * cachelines if xchg is used.
301  */
302 #define percpu_xchg_op(var, nval)					\
303 ({									\
304 	typeof(var) pxo_ret__;						\
305 	typeof(var) pxo_new__ = (nval);					\
306 	switch (sizeof(var)) {						\
307 	case 1:								\
308 		asm("\n\tmov "__percpu_arg(1)",%%al"			\
309 		    "\n1:\tcmpxchgb %2, "__percpu_arg(1)		\
310 		    "\n\tjnz 1b"					\
311 			    : "=&a" (pxo_ret__), "+m" (var)		\
312 			    : "q" (pxo_new__)				\
313 			    : "memory");				\
314 		break;							\
315 	case 2:								\
316 		asm("\n\tmov "__percpu_arg(1)",%%ax"			\
317 		    "\n1:\tcmpxchgw %2, "__percpu_arg(1)		\
318 		    "\n\tjnz 1b"					\
319 			    : "=&a" (pxo_ret__), "+m" (var)		\
320 			    : "r" (pxo_new__)				\
321 			    : "memory");				\
322 		break;							\
323 	case 4:								\
324 		asm("\n\tmov "__percpu_arg(1)",%%eax"			\
325 		    "\n1:\tcmpxchgl %2, "__percpu_arg(1)		\
326 		    "\n\tjnz 1b"					\
327 			    : "=&a" (pxo_ret__), "+m" (var)		\
328 			    : "r" (pxo_new__)				\
329 			    : "memory");				\
330 		break;							\
331 	case 8:								\
332 		asm("\n\tmov "__percpu_arg(1)",%%rax"			\
333 		    "\n1:\tcmpxchgq %2, "__percpu_arg(1)		\
334 		    "\n\tjnz 1b"					\
335 			    : "=&a" (pxo_ret__), "+m" (var)		\
336 			    : "r" (pxo_new__)				\
337 			    : "memory");				\
338 		break;							\
339 	default: __bad_percpu_size();					\
340 	}								\
341 	pxo_ret__;							\
342 })
343 
344 /*
345  * cmpxchg has no such implied lock semantics as a result it is much
346  * more efficient for cpu local operations.
347  */
348 #define percpu_cmpxchg_op(var, oval, nval)				\
349 ({									\
350 	typeof(var) pco_ret__;						\
351 	typeof(var) pco_old__ = (oval);					\
352 	typeof(var) pco_new__ = (nval);					\
353 	switch (sizeof(var)) {						\
354 	case 1:								\
355 		asm("cmpxchgb %2, "__percpu_arg(1)			\
356 			    : "=a" (pco_ret__), "+m" (var)		\
357 			    : "q" (pco_new__), "0" (pco_old__)		\
358 			    : "memory");				\
359 		break;							\
360 	case 2:								\
361 		asm("cmpxchgw %2, "__percpu_arg(1)			\
362 			    : "=a" (pco_ret__), "+m" (var)		\
363 			    : "r" (pco_new__), "0" (pco_old__)		\
364 			    : "memory");				\
365 		break;							\
366 	case 4:								\
367 		asm("cmpxchgl %2, "__percpu_arg(1)			\
368 			    : "=a" (pco_ret__), "+m" (var)		\
369 			    : "r" (pco_new__), "0" (pco_old__)		\
370 			    : "memory");				\
371 		break;							\
372 	case 8:								\
373 		asm("cmpxchgq %2, "__percpu_arg(1)			\
374 			    : "=a" (pco_ret__), "+m" (var)		\
375 			    : "r" (pco_new__), "0" (pco_old__)		\
376 			    : "memory");				\
377 		break;							\
378 	default: __bad_percpu_size();					\
379 	}								\
380 	pco_ret__;							\
381 })
382 
383 /*
384  * this_cpu_read() makes gcc load the percpu variable every time it is
385  * accessed while this_cpu_read_stable() allows the value to be cached.
386  * this_cpu_read_stable() is more efficient and can be used if its value
387  * is guaranteed to be valid across cpus.  The current users include
388  * get_current() and get_thread_info() both of which are actually
389  * per-thread variables implemented as per-cpu variables and thus
390  * stable for the duration of the respective task.
391  */
392 #define this_cpu_read_stable(var)	percpu_stable_op("mov", var)
393 
394 #define raw_cpu_read_1(pcp)		percpu_from_op("mov", pcp)
395 #define raw_cpu_read_2(pcp)		percpu_from_op("mov", pcp)
396 #define raw_cpu_read_4(pcp)		percpu_from_op("mov", pcp)
397 
398 #define raw_cpu_write_1(pcp, val)	percpu_to_op("mov", (pcp), val)
399 #define raw_cpu_write_2(pcp, val)	percpu_to_op("mov", (pcp), val)
400 #define raw_cpu_write_4(pcp, val)	percpu_to_op("mov", (pcp), val)
401 #define raw_cpu_add_1(pcp, val)		percpu_add_op((pcp), val)
402 #define raw_cpu_add_2(pcp, val)		percpu_add_op((pcp), val)
403 #define raw_cpu_add_4(pcp, val)		percpu_add_op((pcp), val)
404 #define raw_cpu_and_1(pcp, val)		percpu_to_op("and", (pcp), val)
405 #define raw_cpu_and_2(pcp, val)		percpu_to_op("and", (pcp), val)
406 #define raw_cpu_and_4(pcp, val)		percpu_to_op("and", (pcp), val)
407 #define raw_cpu_or_1(pcp, val)		percpu_to_op("or", (pcp), val)
408 #define raw_cpu_or_2(pcp, val)		percpu_to_op("or", (pcp), val)
409 #define raw_cpu_or_4(pcp, val)		percpu_to_op("or", (pcp), val)
410 #define raw_cpu_xchg_1(pcp, val)	percpu_xchg_op(pcp, val)
411 #define raw_cpu_xchg_2(pcp, val)	percpu_xchg_op(pcp, val)
412 #define raw_cpu_xchg_4(pcp, val)	percpu_xchg_op(pcp, val)
413 
414 #define this_cpu_read_1(pcp)		percpu_from_op("mov", pcp)
415 #define this_cpu_read_2(pcp)		percpu_from_op("mov", pcp)
416 #define this_cpu_read_4(pcp)		percpu_from_op("mov", pcp)
417 #define this_cpu_write_1(pcp, val)	percpu_to_op("mov", (pcp), val)
418 #define this_cpu_write_2(pcp, val)	percpu_to_op("mov", (pcp), val)
419 #define this_cpu_write_4(pcp, val)	percpu_to_op("mov", (pcp), val)
420 #define this_cpu_add_1(pcp, val)	percpu_add_op((pcp), val)
421 #define this_cpu_add_2(pcp, val)	percpu_add_op((pcp), val)
422 #define this_cpu_add_4(pcp, val)	percpu_add_op((pcp), val)
423 #define this_cpu_and_1(pcp, val)	percpu_to_op("and", (pcp), val)
424 #define this_cpu_and_2(pcp, val)	percpu_to_op("and", (pcp), val)
425 #define this_cpu_and_4(pcp, val)	percpu_to_op("and", (pcp), val)
426 #define this_cpu_or_1(pcp, val)		percpu_to_op("or", (pcp), val)
427 #define this_cpu_or_2(pcp, val)		percpu_to_op("or", (pcp), val)
428 #define this_cpu_or_4(pcp, val)		percpu_to_op("or", (pcp), val)
429 #define this_cpu_xchg_1(pcp, nval)	percpu_xchg_op(pcp, nval)
430 #define this_cpu_xchg_2(pcp, nval)	percpu_xchg_op(pcp, nval)
431 #define this_cpu_xchg_4(pcp, nval)	percpu_xchg_op(pcp, nval)
432 
433 #define raw_cpu_add_return_1(pcp, val)		percpu_add_return_op(pcp, val)
434 #define raw_cpu_add_return_2(pcp, val)		percpu_add_return_op(pcp, val)
435 #define raw_cpu_add_return_4(pcp, val)		percpu_add_return_op(pcp, val)
436 #define raw_cpu_cmpxchg_1(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
437 #define raw_cpu_cmpxchg_2(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
438 #define raw_cpu_cmpxchg_4(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
439 
440 #define this_cpu_add_return_1(pcp, val)		percpu_add_return_op(pcp, val)
441 #define this_cpu_add_return_2(pcp, val)		percpu_add_return_op(pcp, val)
442 #define this_cpu_add_return_4(pcp, val)		percpu_add_return_op(pcp, val)
443 #define this_cpu_cmpxchg_1(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
444 #define this_cpu_cmpxchg_2(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
445 #define this_cpu_cmpxchg_4(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
446 
447 #ifdef CONFIG_X86_CMPXCHG64
448 #define percpu_cmpxchg8b_double(pcp1, pcp2, o1, o2, n1, n2)		\
449 ({									\
450 	bool __ret;							\
451 	typeof(pcp1) __o1 = (o1), __n1 = (n1);				\
452 	typeof(pcp2) __o2 = (o2), __n2 = (n2);				\
453 	asm volatile("cmpxchg8b "__percpu_arg(1)"\n\tsetz %0\n\t"	\
454 		    : "=a" (__ret), "+m" (pcp1), "+m" (pcp2), "+d" (__o2) \
455 		    :  "b" (__n1), "c" (__n2), "a" (__o1));		\
456 	__ret;								\
457 })
458 
459 #define raw_cpu_cmpxchg_double_4	percpu_cmpxchg8b_double
460 #define this_cpu_cmpxchg_double_4	percpu_cmpxchg8b_double
461 #endif /* CONFIG_X86_CMPXCHG64 */
462 
463 /*
464  * Per cpu atomic 64 bit operations are only available under 64 bit.
465  * 32 bit must fall back to generic operations.
466  */
467 #ifdef CONFIG_X86_64
468 #define raw_cpu_read_8(pcp)			percpu_from_op("mov", pcp)
469 #define raw_cpu_write_8(pcp, val)		percpu_to_op("mov", (pcp), val)
470 #define raw_cpu_add_8(pcp, val)			percpu_add_op((pcp), val)
471 #define raw_cpu_and_8(pcp, val)			percpu_to_op("and", (pcp), val)
472 #define raw_cpu_or_8(pcp, val)			percpu_to_op("or", (pcp), val)
473 #define raw_cpu_add_return_8(pcp, val)		percpu_add_return_op(pcp, val)
474 #define raw_cpu_xchg_8(pcp, nval)		percpu_xchg_op(pcp, nval)
475 #define raw_cpu_cmpxchg_8(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
476 
477 #define this_cpu_read_8(pcp)			percpu_from_op("mov", pcp)
478 #define this_cpu_write_8(pcp, val)		percpu_to_op("mov", (pcp), val)
479 #define this_cpu_add_8(pcp, val)		percpu_add_op((pcp), val)
480 #define this_cpu_and_8(pcp, val)		percpu_to_op("and", (pcp), val)
481 #define this_cpu_or_8(pcp, val)			percpu_to_op("or", (pcp), val)
482 #define this_cpu_add_return_8(pcp, val)		percpu_add_return_op(pcp, val)
483 #define this_cpu_xchg_8(pcp, nval)		percpu_xchg_op(pcp, nval)
484 #define this_cpu_cmpxchg_8(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
485 
486 /*
487  * Pretty complex macro to generate cmpxchg16 instruction.  The instruction
488  * is not supported on early AMD64 processors so we must be able to emulate
489  * it in software.  The address used in the cmpxchg16 instruction must be
490  * aligned to a 16 byte boundary.
491  */
492 #define percpu_cmpxchg16b_double(pcp1, pcp2, o1, o2, n1, n2)		\
493 ({									\
494 	bool __ret;							\
495 	typeof(pcp1) __o1 = (o1), __n1 = (n1);				\
496 	typeof(pcp2) __o2 = (o2), __n2 = (n2);				\
497 	alternative_io("leaq %P1,%%rsi\n\tcall this_cpu_cmpxchg16b_emu\n\t", \
498 		       "cmpxchg16b " __percpu_arg(1) "\n\tsetz %0\n\t",	\
499 		       X86_FEATURE_CX16,				\
500 		       ASM_OUTPUT2("=a" (__ret), "+m" (pcp1),		\
501 				   "+m" (pcp2), "+d" (__o2)),		\
502 		       "b" (__n1), "c" (__n2), "a" (__o1) : "rsi");	\
503 	__ret;								\
504 })
505 
506 #define raw_cpu_cmpxchg_double_8	percpu_cmpxchg16b_double
507 #define this_cpu_cmpxchg_double_8	percpu_cmpxchg16b_double
508 
509 #endif
510 
511 static __always_inline bool x86_this_cpu_constant_test_bit(unsigned int nr,
512                         const unsigned long __percpu *addr)
513 {
514 	unsigned long __percpu *a =
515 		(unsigned long __percpu *)addr + nr / BITS_PER_LONG;
516 
517 #ifdef CONFIG_X86_64
518 	return ((1UL << (nr % BITS_PER_LONG)) & raw_cpu_read_8(*a)) != 0;
519 #else
520 	return ((1UL << (nr % BITS_PER_LONG)) & raw_cpu_read_4(*a)) != 0;
521 #endif
522 }
523 
524 static inline bool x86_this_cpu_variable_test_bit(int nr,
525                         const unsigned long __percpu *addr)
526 {
527 	bool oldbit;
528 
529 	asm volatile("btl "__percpu_arg(2)",%1"
530 			CC_SET(c)
531 			: CC_OUT(c) (oldbit)
532 			: "m" (*(unsigned long __percpu *)addr), "Ir" (nr));
533 
534 	return oldbit;
535 }
536 
537 #define x86_this_cpu_test_bit(nr, addr)			\
538 	(__builtin_constant_p((nr))			\
539 	 ? x86_this_cpu_constant_test_bit((nr), (addr))	\
540 	 : x86_this_cpu_variable_test_bit((nr), (addr)))
541 
542 
543 #include <asm-generic/percpu.h>
544 
545 /* We can use this directly for local CPU (faster). */
546 DECLARE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off);
547 
548 #endif /* !__ASSEMBLY__ */
549 
550 #ifdef CONFIG_SMP
551 
552 /*
553  * Define the "EARLY_PER_CPU" macros.  These are used for some per_cpu
554  * variables that are initialized and accessed before there are per_cpu
555  * areas allocated.
556  */
557 
558 #define	DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)			\
559 	DEFINE_PER_CPU(_type, _name) = _initvalue;			\
560 	__typeof__(_type) _name##_early_map[NR_CPUS] __initdata =	\
561 				{ [0 ... NR_CPUS-1] = _initvalue };	\
562 	__typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
563 
564 #define DEFINE_EARLY_PER_CPU_READ_MOSTLY(_type, _name, _initvalue)	\
565 	DEFINE_PER_CPU_READ_MOSTLY(_type, _name) = _initvalue;		\
566 	__typeof__(_type) _name##_early_map[NR_CPUS] __initdata =	\
567 				{ [0 ... NR_CPUS-1] = _initvalue };	\
568 	__typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
569 
570 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name)			\
571 	EXPORT_PER_CPU_SYMBOL(_name)
572 
573 #define DECLARE_EARLY_PER_CPU(_type, _name)			\
574 	DECLARE_PER_CPU(_type, _name);				\
575 	extern __typeof__(_type) *_name##_early_ptr;		\
576 	extern __typeof__(_type)  _name##_early_map[]
577 
578 #define DECLARE_EARLY_PER_CPU_READ_MOSTLY(_type, _name)		\
579 	DECLARE_PER_CPU_READ_MOSTLY(_type, _name);		\
580 	extern __typeof__(_type) *_name##_early_ptr;		\
581 	extern __typeof__(_type)  _name##_early_map[]
582 
583 #define	early_per_cpu_ptr(_name) (_name##_early_ptr)
584 #define	early_per_cpu_map(_name, _idx) (_name##_early_map[_idx])
585 #define	early_per_cpu(_name, _cpu) 				\
586 	*(early_per_cpu_ptr(_name) ?				\
587 		&early_per_cpu_ptr(_name)[_cpu] :		\
588 		&per_cpu(_name, _cpu))
589 
590 #else	/* !CONFIG_SMP */
591 #define	DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)		\
592 	DEFINE_PER_CPU(_type, _name) = _initvalue
593 
594 #define DEFINE_EARLY_PER_CPU_READ_MOSTLY(_type, _name, _initvalue)	\
595 	DEFINE_PER_CPU_READ_MOSTLY(_type, _name) = _initvalue
596 
597 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name)			\
598 	EXPORT_PER_CPU_SYMBOL(_name)
599 
600 #define DECLARE_EARLY_PER_CPU(_type, _name)			\
601 	DECLARE_PER_CPU(_type, _name)
602 
603 #define DECLARE_EARLY_PER_CPU_READ_MOSTLY(_type, _name)		\
604 	DECLARE_PER_CPU_READ_MOSTLY(_type, _name)
605 
606 #define	early_per_cpu(_name, _cpu) per_cpu(_name, _cpu)
607 #define	early_per_cpu_ptr(_name) NULL
608 /* no early_per_cpu_map() */
609 
610 #endif	/* !CONFIG_SMP */
611 
612 #endif /* _ASM_X86_PERCPU_H */
613