xref: /openbmc/linux/arch/x86/include/asm/percpu.h (revision 930beb5a)
1 #ifndef _ASM_X86_PERCPU_H
2 #define _ASM_X86_PERCPU_H
3 
4 #ifdef CONFIG_X86_64
5 #define __percpu_seg		gs
6 #define __percpu_mov_op		movq
7 #else
8 #define __percpu_seg		fs
9 #define __percpu_mov_op		movl
10 #endif
11 
12 #ifdef __ASSEMBLY__
13 
14 /*
15  * PER_CPU finds an address of a per-cpu variable.
16  *
17  * Args:
18  *    var - variable name
19  *    reg - 32bit register
20  *
21  * The resulting address is stored in the "reg" argument.
22  *
23  * Example:
24  *    PER_CPU(cpu_gdt_descr, %ebx)
25  */
26 #ifdef CONFIG_SMP
27 #define PER_CPU(var, reg)						\
28 	__percpu_mov_op %__percpu_seg:this_cpu_off, reg;		\
29 	lea var(reg), reg
30 #define PER_CPU_VAR(var)	%__percpu_seg:var
31 #else /* ! SMP */
32 #define PER_CPU(var, reg)	__percpu_mov_op $var, reg
33 #define PER_CPU_VAR(var)	var
34 #endif	/* SMP */
35 
36 #ifdef CONFIG_X86_64_SMP
37 #define INIT_PER_CPU_VAR(var)  init_per_cpu__##var
38 #else
39 #define INIT_PER_CPU_VAR(var)  var
40 #endif
41 
42 #else /* ...!ASSEMBLY */
43 
44 #include <linux/kernel.h>
45 #include <linux/stringify.h>
46 
47 #ifdef CONFIG_SMP
48 #define __percpu_prefix		"%%"__stringify(__percpu_seg)":"
49 #define __my_cpu_offset		this_cpu_read(this_cpu_off)
50 
51 /*
52  * Compared to the generic __my_cpu_offset version, the following
53  * saves one instruction and avoids clobbering a temp register.
54  */
55 #define __this_cpu_ptr(ptr)				\
56 ({							\
57 	unsigned long tcp_ptr__;			\
58 	__verify_pcpu_ptr(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 "%P" #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, constraint)		\
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 		    : constraint);			\
191 		break;					\
192 	case 2:						\
193 		asm(op "w "__percpu_arg(1)",%0"		\
194 		    : "=r" (pfo_ret__)			\
195 		    : constraint);			\
196 		break;					\
197 	case 4:						\
198 		asm(op "l "__percpu_arg(1)",%0"		\
199 		    : "=r" (pfo_ret__)			\
200 		    : constraint);			\
201 		break;					\
202 	case 8:						\
203 		asm(op "q "__percpu_arg(1)",%0"		\
204 		    : "=r" (pfo_ret__)			\
205 		    : constraint);			\
206 		break;					\
207 	default: __bad_percpu_size();			\
208 	}						\
209 	pfo_ret__;					\
210 })
211 
212 #define percpu_unary_op(op, var)			\
213 ({							\
214 	switch (sizeof(var)) {				\
215 	case 1:						\
216 		asm(op "b "__percpu_arg(0)		\
217 		    : "+m" (var));			\
218 		break;					\
219 	case 2:						\
220 		asm(op "w "__percpu_arg(0)		\
221 		    : "+m" (var));			\
222 		break;					\
223 	case 4:						\
224 		asm(op "l "__percpu_arg(0)		\
225 		    : "+m" (var));			\
226 		break;					\
227 	case 8:						\
228 		asm(op "q "__percpu_arg(0)		\
229 		    : "+m" (var));			\
230 		break;					\
231 	default: __bad_percpu_size();			\
232 	}						\
233 })
234 
235 /*
236  * Add return operation
237  */
238 #define percpu_add_return_op(var, val)					\
239 ({									\
240 	typeof(var) paro_ret__ = val;					\
241 	switch (sizeof(var)) {						\
242 	case 1:								\
243 		asm("xaddb %0, "__percpu_arg(1)				\
244 			    : "+q" (paro_ret__), "+m" (var)		\
245 			    : : "memory");				\
246 		break;							\
247 	case 2:								\
248 		asm("xaddw %0, "__percpu_arg(1)				\
249 			    : "+r" (paro_ret__), "+m" (var)		\
250 			    : : "memory");				\
251 		break;							\
252 	case 4:								\
253 		asm("xaddl %0, "__percpu_arg(1)				\
254 			    : "+r" (paro_ret__), "+m" (var)		\
255 			    : : "memory");				\
256 		break;							\
257 	case 8:								\
258 		asm("xaddq %0, "__percpu_arg(1)				\
259 			    : "+re" (paro_ret__), "+m" (var)		\
260 			    : : "memory");				\
261 		break;							\
262 	default: __bad_percpu_size();					\
263 	}								\
264 	paro_ret__ += val;						\
265 	paro_ret__;							\
266 })
267 
268 /*
269  * xchg is implemented using cmpxchg without a lock prefix. xchg is
270  * expensive due to the implied lock prefix.  The processor cannot prefetch
271  * cachelines if xchg is used.
272  */
273 #define percpu_xchg_op(var, nval)					\
274 ({									\
275 	typeof(var) pxo_ret__;						\
276 	typeof(var) pxo_new__ = (nval);					\
277 	switch (sizeof(var)) {						\
278 	case 1:								\
279 		asm("\n\tmov "__percpu_arg(1)",%%al"			\
280 		    "\n1:\tcmpxchgb %2, "__percpu_arg(1)		\
281 		    "\n\tjnz 1b"					\
282 			    : "=&a" (pxo_ret__), "+m" (var)		\
283 			    : "q" (pxo_new__)				\
284 			    : "memory");				\
285 		break;							\
286 	case 2:								\
287 		asm("\n\tmov "__percpu_arg(1)",%%ax"			\
288 		    "\n1:\tcmpxchgw %2, "__percpu_arg(1)		\
289 		    "\n\tjnz 1b"					\
290 			    : "=&a" (pxo_ret__), "+m" (var)		\
291 			    : "r" (pxo_new__)				\
292 			    : "memory");				\
293 		break;							\
294 	case 4:								\
295 		asm("\n\tmov "__percpu_arg(1)",%%eax"			\
296 		    "\n1:\tcmpxchgl %2, "__percpu_arg(1)		\
297 		    "\n\tjnz 1b"					\
298 			    : "=&a" (pxo_ret__), "+m" (var)		\
299 			    : "r" (pxo_new__)				\
300 			    : "memory");				\
301 		break;							\
302 	case 8:								\
303 		asm("\n\tmov "__percpu_arg(1)",%%rax"			\
304 		    "\n1:\tcmpxchgq %2, "__percpu_arg(1)		\
305 		    "\n\tjnz 1b"					\
306 			    : "=&a" (pxo_ret__), "+m" (var)		\
307 			    : "r" (pxo_new__)				\
308 			    : "memory");				\
309 		break;							\
310 	default: __bad_percpu_size();					\
311 	}								\
312 	pxo_ret__;							\
313 })
314 
315 /*
316  * cmpxchg has no such implied lock semantics as a result it is much
317  * more efficient for cpu local operations.
318  */
319 #define percpu_cmpxchg_op(var, oval, nval)				\
320 ({									\
321 	typeof(var) pco_ret__;						\
322 	typeof(var) pco_old__ = (oval);					\
323 	typeof(var) pco_new__ = (nval);					\
324 	switch (sizeof(var)) {						\
325 	case 1:								\
326 		asm("cmpxchgb %2, "__percpu_arg(1)			\
327 			    : "=a" (pco_ret__), "+m" (var)		\
328 			    : "q" (pco_new__), "0" (pco_old__)		\
329 			    : "memory");				\
330 		break;							\
331 	case 2:								\
332 		asm("cmpxchgw %2, "__percpu_arg(1)			\
333 			    : "=a" (pco_ret__), "+m" (var)		\
334 			    : "r" (pco_new__), "0" (pco_old__)		\
335 			    : "memory");				\
336 		break;							\
337 	case 4:								\
338 		asm("cmpxchgl %2, "__percpu_arg(1)			\
339 			    : "=a" (pco_ret__), "+m" (var)		\
340 			    : "r" (pco_new__), "0" (pco_old__)		\
341 			    : "memory");				\
342 		break;							\
343 	case 8:								\
344 		asm("cmpxchgq %2, "__percpu_arg(1)			\
345 			    : "=a" (pco_ret__), "+m" (var)		\
346 			    : "r" (pco_new__), "0" (pco_old__)		\
347 			    : "memory");				\
348 		break;							\
349 	default: __bad_percpu_size();					\
350 	}								\
351 	pco_ret__;							\
352 })
353 
354 /*
355  * this_cpu_read() makes gcc load the percpu variable every time it is
356  * accessed while this_cpu_read_stable() allows the value to be cached.
357  * this_cpu_read_stable() is more efficient and can be used if its value
358  * is guaranteed to be valid across cpus.  The current users include
359  * get_current() and get_thread_info() both of which are actually
360  * per-thread variables implemented as per-cpu variables and thus
361  * stable for the duration of the respective task.
362  */
363 #define this_cpu_read_stable(var)	percpu_from_op("mov", var, "p" (&(var)))
364 
365 #define __this_cpu_read_1(pcp)		percpu_from_op("mov", (pcp), "m"(pcp))
366 #define __this_cpu_read_2(pcp)		percpu_from_op("mov", (pcp), "m"(pcp))
367 #define __this_cpu_read_4(pcp)		percpu_from_op("mov", (pcp), "m"(pcp))
368 
369 #define __this_cpu_write_1(pcp, val)	percpu_to_op("mov", (pcp), val)
370 #define __this_cpu_write_2(pcp, val)	percpu_to_op("mov", (pcp), val)
371 #define __this_cpu_write_4(pcp, val)	percpu_to_op("mov", (pcp), val)
372 #define __this_cpu_add_1(pcp, val)	percpu_add_op((pcp), val)
373 #define __this_cpu_add_2(pcp, val)	percpu_add_op((pcp), val)
374 #define __this_cpu_add_4(pcp, val)	percpu_add_op((pcp), val)
375 #define __this_cpu_and_1(pcp, val)	percpu_to_op("and", (pcp), val)
376 #define __this_cpu_and_2(pcp, val)	percpu_to_op("and", (pcp), val)
377 #define __this_cpu_and_4(pcp, val)	percpu_to_op("and", (pcp), val)
378 #define __this_cpu_or_1(pcp, val)	percpu_to_op("or", (pcp), val)
379 #define __this_cpu_or_2(pcp, val)	percpu_to_op("or", (pcp), val)
380 #define __this_cpu_or_4(pcp, val)	percpu_to_op("or", (pcp), val)
381 #define __this_cpu_xchg_1(pcp, val)	percpu_xchg_op(pcp, val)
382 #define __this_cpu_xchg_2(pcp, val)	percpu_xchg_op(pcp, val)
383 #define __this_cpu_xchg_4(pcp, val)	percpu_xchg_op(pcp, val)
384 
385 #define this_cpu_read_1(pcp)		percpu_from_op("mov", (pcp), "m"(pcp))
386 #define this_cpu_read_2(pcp)		percpu_from_op("mov", (pcp), "m"(pcp))
387 #define this_cpu_read_4(pcp)		percpu_from_op("mov", (pcp), "m"(pcp))
388 #define this_cpu_write_1(pcp, val)	percpu_to_op("mov", (pcp), val)
389 #define this_cpu_write_2(pcp, val)	percpu_to_op("mov", (pcp), val)
390 #define this_cpu_write_4(pcp, val)	percpu_to_op("mov", (pcp), val)
391 #define this_cpu_add_1(pcp, val)	percpu_add_op((pcp), val)
392 #define this_cpu_add_2(pcp, val)	percpu_add_op((pcp), val)
393 #define this_cpu_add_4(pcp, val)	percpu_add_op((pcp), val)
394 #define this_cpu_and_1(pcp, val)	percpu_to_op("and", (pcp), val)
395 #define this_cpu_and_2(pcp, val)	percpu_to_op("and", (pcp), val)
396 #define this_cpu_and_4(pcp, val)	percpu_to_op("and", (pcp), val)
397 #define this_cpu_or_1(pcp, val)		percpu_to_op("or", (pcp), val)
398 #define this_cpu_or_2(pcp, val)		percpu_to_op("or", (pcp), val)
399 #define this_cpu_or_4(pcp, val)		percpu_to_op("or", (pcp), val)
400 #define this_cpu_xchg_1(pcp, nval)	percpu_xchg_op(pcp, nval)
401 #define this_cpu_xchg_2(pcp, nval)	percpu_xchg_op(pcp, nval)
402 #define this_cpu_xchg_4(pcp, nval)	percpu_xchg_op(pcp, nval)
403 
404 #define __this_cpu_add_return_1(pcp, val) percpu_add_return_op(pcp, val)
405 #define __this_cpu_add_return_2(pcp, val) percpu_add_return_op(pcp, val)
406 #define __this_cpu_add_return_4(pcp, val) percpu_add_return_op(pcp, val)
407 #define __this_cpu_cmpxchg_1(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
408 #define __this_cpu_cmpxchg_2(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
409 #define __this_cpu_cmpxchg_4(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
410 
411 #define this_cpu_add_return_1(pcp, val)	percpu_add_return_op(pcp, val)
412 #define this_cpu_add_return_2(pcp, val)	percpu_add_return_op(pcp, val)
413 #define this_cpu_add_return_4(pcp, val)	percpu_add_return_op(pcp, val)
414 #define this_cpu_cmpxchg_1(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
415 #define this_cpu_cmpxchg_2(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
416 #define this_cpu_cmpxchg_4(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
417 
418 #ifdef CONFIG_X86_CMPXCHG64
419 #define percpu_cmpxchg8b_double(pcp1, pcp2, o1, o2, n1, n2)		\
420 ({									\
421 	bool __ret;							\
422 	typeof(pcp1) __o1 = (o1), __n1 = (n1);				\
423 	typeof(pcp2) __o2 = (o2), __n2 = (n2);				\
424 	asm volatile("cmpxchg8b "__percpu_arg(1)"\n\tsetz %0\n\t"	\
425 		    : "=a" (__ret), "+m" (pcp1), "+m" (pcp2), "+d" (__o2) \
426 		    :  "b" (__n1), "c" (__n2), "a" (__o1));		\
427 	__ret;								\
428 })
429 
430 #define __this_cpu_cmpxchg_double_4	percpu_cmpxchg8b_double
431 #define this_cpu_cmpxchg_double_4	percpu_cmpxchg8b_double
432 #endif /* CONFIG_X86_CMPXCHG64 */
433 
434 /*
435  * Per cpu atomic 64 bit operations are only available under 64 bit.
436  * 32 bit must fall back to generic operations.
437  */
438 #ifdef CONFIG_X86_64
439 #define __this_cpu_read_8(pcp)		percpu_from_op("mov", (pcp), "m"(pcp))
440 #define __this_cpu_write_8(pcp, val)	percpu_to_op("mov", (pcp), val)
441 #define __this_cpu_add_8(pcp, val)	percpu_add_op((pcp), val)
442 #define __this_cpu_and_8(pcp, val)	percpu_to_op("and", (pcp), val)
443 #define __this_cpu_or_8(pcp, val)	percpu_to_op("or", (pcp), val)
444 #define __this_cpu_add_return_8(pcp, val) percpu_add_return_op(pcp, val)
445 #define __this_cpu_xchg_8(pcp, nval)	percpu_xchg_op(pcp, nval)
446 #define __this_cpu_cmpxchg_8(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
447 
448 #define this_cpu_read_8(pcp)		percpu_from_op("mov", (pcp), "m"(pcp))
449 #define this_cpu_write_8(pcp, val)	percpu_to_op("mov", (pcp), val)
450 #define this_cpu_add_8(pcp, val)	percpu_add_op((pcp), val)
451 #define this_cpu_and_8(pcp, val)	percpu_to_op("and", (pcp), val)
452 #define this_cpu_or_8(pcp, val)		percpu_to_op("or", (pcp), val)
453 #define this_cpu_add_return_8(pcp, val)	percpu_add_return_op(pcp, val)
454 #define this_cpu_xchg_8(pcp, nval)	percpu_xchg_op(pcp, nval)
455 #define this_cpu_cmpxchg_8(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
456 
457 /*
458  * Pretty complex macro to generate cmpxchg16 instruction.  The instruction
459  * is not supported on early AMD64 processors so we must be able to emulate
460  * it in software.  The address used in the cmpxchg16 instruction must be
461  * aligned to a 16 byte boundary.
462  */
463 #define percpu_cmpxchg16b_double(pcp1, pcp2, o1, o2, n1, n2)		\
464 ({									\
465 	bool __ret;							\
466 	typeof(pcp1) __o1 = (o1), __n1 = (n1);				\
467 	typeof(pcp2) __o2 = (o2), __n2 = (n2);				\
468 	alternative_io("leaq %P1,%%rsi\n\tcall this_cpu_cmpxchg16b_emu\n\t", \
469 		       "cmpxchg16b " __percpu_arg(1) "\n\tsetz %0\n\t",	\
470 		       X86_FEATURE_CX16,				\
471 		       ASM_OUTPUT2("=a" (__ret), "+m" (pcp1),		\
472 				   "+m" (pcp2), "+d" (__o2)),		\
473 		       "b" (__n1), "c" (__n2), "a" (__o1) : "rsi");	\
474 	__ret;								\
475 })
476 
477 #define __this_cpu_cmpxchg_double_8	percpu_cmpxchg16b_double
478 #define this_cpu_cmpxchg_double_8	percpu_cmpxchg16b_double
479 
480 #endif
481 
482 /* This is not atomic against other CPUs -- CPU preemption needs to be off */
483 #define x86_test_and_clear_bit_percpu(bit, var)				\
484 ({									\
485 	int old__;							\
486 	asm volatile("btr %2,"__percpu_arg(1)"\n\tsbbl %0,%0"		\
487 		     : "=r" (old__), "+m" (var)				\
488 		     : "dIr" (bit));					\
489 	old__;								\
490 })
491 
492 static __always_inline int x86_this_cpu_constant_test_bit(unsigned int nr,
493                         const unsigned long __percpu *addr)
494 {
495 	unsigned long __percpu *a = (unsigned long *)addr + nr / BITS_PER_LONG;
496 
497 #ifdef CONFIG_X86_64
498 	return ((1UL << (nr % BITS_PER_LONG)) & __this_cpu_read_8(*a)) != 0;
499 #else
500 	return ((1UL << (nr % BITS_PER_LONG)) & __this_cpu_read_4(*a)) != 0;
501 #endif
502 }
503 
504 static inline int x86_this_cpu_variable_test_bit(int nr,
505                         const unsigned long __percpu *addr)
506 {
507 	int oldbit;
508 
509 	asm volatile("bt "__percpu_arg(2)",%1\n\t"
510 			"sbb %0,%0"
511 			: "=r" (oldbit)
512 			: "m" (*(unsigned long *)addr), "Ir" (nr));
513 
514 	return oldbit;
515 }
516 
517 #define x86_this_cpu_test_bit(nr, addr)			\
518 	(__builtin_constant_p((nr))			\
519 	 ? x86_this_cpu_constant_test_bit((nr), (addr))	\
520 	 : x86_this_cpu_variable_test_bit((nr), (addr)))
521 
522 
523 #include <asm-generic/percpu.h>
524 
525 /* We can use this directly for local CPU (faster). */
526 DECLARE_PER_CPU(unsigned long, this_cpu_off);
527 
528 #endif /* !__ASSEMBLY__ */
529 
530 #ifdef CONFIG_SMP
531 
532 /*
533  * Define the "EARLY_PER_CPU" macros.  These are used for some per_cpu
534  * variables that are initialized and accessed before there are per_cpu
535  * areas allocated.
536  */
537 
538 #define	DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)			\
539 	DEFINE_PER_CPU(_type, _name) = _initvalue;			\
540 	__typeof__(_type) _name##_early_map[NR_CPUS] __initdata =	\
541 				{ [0 ... NR_CPUS-1] = _initvalue };	\
542 	__typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
543 
544 #define DEFINE_EARLY_PER_CPU_READ_MOSTLY(_type, _name, _initvalue)	\
545 	DEFINE_PER_CPU_READ_MOSTLY(_type, _name) = _initvalue;		\
546 	__typeof__(_type) _name##_early_map[NR_CPUS] __initdata =	\
547 				{ [0 ... NR_CPUS-1] = _initvalue };	\
548 	__typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
549 
550 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name)			\
551 	EXPORT_PER_CPU_SYMBOL(_name)
552 
553 #define DECLARE_EARLY_PER_CPU(_type, _name)			\
554 	DECLARE_PER_CPU(_type, _name);				\
555 	extern __typeof__(_type) *_name##_early_ptr;		\
556 	extern __typeof__(_type)  _name##_early_map[]
557 
558 #define DECLARE_EARLY_PER_CPU_READ_MOSTLY(_type, _name)		\
559 	DECLARE_PER_CPU_READ_MOSTLY(_type, _name);		\
560 	extern __typeof__(_type) *_name##_early_ptr;		\
561 	extern __typeof__(_type)  _name##_early_map[]
562 
563 #define	early_per_cpu_ptr(_name) (_name##_early_ptr)
564 #define	early_per_cpu_map(_name, _idx) (_name##_early_map[_idx])
565 #define	early_per_cpu(_name, _cpu) 				\
566 	*(early_per_cpu_ptr(_name) ?				\
567 		&early_per_cpu_ptr(_name)[_cpu] :		\
568 		&per_cpu(_name, _cpu))
569 
570 #else	/* !CONFIG_SMP */
571 #define	DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)		\
572 	DEFINE_PER_CPU(_type, _name) = _initvalue
573 
574 #define DEFINE_EARLY_PER_CPU_READ_MOSTLY(_type, _name, _initvalue)	\
575 	DEFINE_PER_CPU_READ_MOSTLY(_type, _name) = _initvalue
576 
577 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name)			\
578 	EXPORT_PER_CPU_SYMBOL(_name)
579 
580 #define DECLARE_EARLY_PER_CPU(_type, _name)			\
581 	DECLARE_PER_CPU(_type, _name)
582 
583 #define DECLARE_EARLY_PER_CPU_READ_MOSTLY(_type, _name)		\
584 	DECLARE_PER_CPU_READ_MOSTLY(_type, _name)
585 
586 #define	early_per_cpu(_name, _cpu) per_cpu(_name, _cpu)
587 #define	early_per_cpu_ptr(_name) NULL
588 /* no early_per_cpu_map() */
589 
590 #endif	/* !CONFIG_SMP */
591 
592 #endif /* _ASM_X86_PERCPU_H */
593