xref: /linux/arch/x86/include/asm/percpu.h (revision 04eeb606a8383b306f4bc6991da8231b5f3924b0)
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 arch_raw_cpu_ptr(ptr)				\
56 ({							\
57 	unsigned long tcp_ptr__;			\
58 	asm volatile("add " __percpu_arg(1) ", %0"	\
59 		     : "=r" (tcp_ptr__)			\
60 		     : "m" (this_cpu_off), "0" (ptr));	\
61 	(typeof(*(ptr)) __kernel __force *)tcp_ptr__;	\
62 })
63 #else
64 #define __percpu_prefix		""
65 #endif
66 
67 #define __percpu_arg(x)		__percpu_prefix "%P" #x
68 
69 /*
70  * Initialized pointers to per-cpu variables needed for the boot
71  * processor need to use these macros to get the proper address
72  * offset from __per_cpu_load on SMP.
73  *
74  * There also must be an entry in vmlinux_64.lds.S
75  */
76 #define DECLARE_INIT_PER_CPU(var) \
77        extern typeof(var) init_per_cpu_var(var)
78 
79 #ifdef CONFIG_X86_64_SMP
80 #define init_per_cpu_var(var)  init_per_cpu__##var
81 #else
82 #define init_per_cpu_var(var)  var
83 #endif
84 
85 /* For arch-specific code, we can use direct single-insn ops (they
86  * don't give an lvalue though). */
87 extern void __bad_percpu_size(void);
88 
89 #define percpu_to_op(op, var, val)			\
90 do {							\
91 	typedef typeof(var) pto_T__;			\
92 	if (0) {					\
93 		pto_T__ pto_tmp__;			\
94 		pto_tmp__ = (val);			\
95 		(void)pto_tmp__;			\
96 	}						\
97 	switch (sizeof(var)) {				\
98 	case 1:						\
99 		asm(op "b %1,"__percpu_arg(0)		\
100 		    : "+m" (var)			\
101 		    : "qi" ((pto_T__)(val)));		\
102 		break;					\
103 	case 2:						\
104 		asm(op "w %1,"__percpu_arg(0)		\
105 		    : "+m" (var)			\
106 		    : "ri" ((pto_T__)(val)));		\
107 		break;					\
108 	case 4:						\
109 		asm(op "l %1,"__percpu_arg(0)		\
110 		    : "+m" (var)			\
111 		    : "ri" ((pto_T__)(val)));		\
112 		break;					\
113 	case 8:						\
114 		asm(op "q %1,"__percpu_arg(0)		\
115 		    : "+m" (var)			\
116 		    : "re" ((pto_T__)(val)));		\
117 		break;					\
118 	default: __bad_percpu_size();			\
119 	}						\
120 } while (0)
121 
122 /*
123  * Generate a percpu add to memory instruction and optimize code
124  * if one is added or subtracted.
125  */
126 #define percpu_add_op(var, val)						\
127 do {									\
128 	typedef typeof(var) pao_T__;					\
129 	const int pao_ID__ = (__builtin_constant_p(val) &&		\
130 			      ((val) == 1 || (val) == -1)) ?		\
131 				(int)(val) : 0;				\
132 	if (0) {							\
133 		pao_T__ pao_tmp__;					\
134 		pao_tmp__ = (val);					\
135 		(void)pao_tmp__;					\
136 	}								\
137 	switch (sizeof(var)) {						\
138 	case 1:								\
139 		if (pao_ID__ == 1)					\
140 			asm("incb "__percpu_arg(0) : "+m" (var));	\
141 		else if (pao_ID__ == -1)				\
142 			asm("decb "__percpu_arg(0) : "+m" (var));	\
143 		else							\
144 			asm("addb %1, "__percpu_arg(0)			\
145 			    : "+m" (var)				\
146 			    : "qi" ((pao_T__)(val)));			\
147 		break;							\
148 	case 2:								\
149 		if (pao_ID__ == 1)					\
150 			asm("incw "__percpu_arg(0) : "+m" (var));	\
151 		else if (pao_ID__ == -1)				\
152 			asm("decw "__percpu_arg(0) : "+m" (var));	\
153 		else							\
154 			asm("addw %1, "__percpu_arg(0)			\
155 			    : "+m" (var)				\
156 			    : "ri" ((pao_T__)(val)));			\
157 		break;							\
158 	case 4:								\
159 		if (pao_ID__ == 1)					\
160 			asm("incl "__percpu_arg(0) : "+m" (var));	\
161 		else if (pao_ID__ == -1)				\
162 			asm("decl "__percpu_arg(0) : "+m" (var));	\
163 		else							\
164 			asm("addl %1, "__percpu_arg(0)			\
165 			    : "+m" (var)				\
166 			    : "ri" ((pao_T__)(val)));			\
167 		break;							\
168 	case 8:								\
169 		if (pao_ID__ == 1)					\
170 			asm("incq "__percpu_arg(0) : "+m" (var));	\
171 		else if (pao_ID__ == -1)				\
172 			asm("decq "__percpu_arg(0) : "+m" (var));	\
173 		else							\
174 			asm("addq %1, "__percpu_arg(0)			\
175 			    : "+m" (var)				\
176 			    : "re" ((pao_T__)(val)));			\
177 		break;							\
178 	default: __bad_percpu_size();					\
179 	}								\
180 } while (0)
181 
182 #define percpu_from_op(op, var, constraint)		\
183 ({							\
184 	typeof(var) pfo_ret__;				\
185 	switch (sizeof(var)) {				\
186 	case 1:						\
187 		asm(op "b "__percpu_arg(1)",%0"		\
188 		    : "=q" (pfo_ret__)			\
189 		    : constraint);			\
190 		break;					\
191 	case 2:						\
192 		asm(op "w "__percpu_arg(1)",%0"		\
193 		    : "=r" (pfo_ret__)			\
194 		    : constraint);			\
195 		break;					\
196 	case 4:						\
197 		asm(op "l "__percpu_arg(1)",%0"		\
198 		    : "=r" (pfo_ret__)			\
199 		    : constraint);			\
200 		break;					\
201 	case 8:						\
202 		asm(op "q "__percpu_arg(1)",%0"		\
203 		    : "=r" (pfo_ret__)			\
204 		    : constraint);			\
205 		break;					\
206 	default: __bad_percpu_size();			\
207 	}						\
208 	pfo_ret__;					\
209 })
210 
211 #define percpu_unary_op(op, var)			\
212 ({							\
213 	switch (sizeof(var)) {				\
214 	case 1:						\
215 		asm(op "b "__percpu_arg(0)		\
216 		    : "+m" (var));			\
217 		break;					\
218 	case 2:						\
219 		asm(op "w "__percpu_arg(0)		\
220 		    : "+m" (var));			\
221 		break;					\
222 	case 4:						\
223 		asm(op "l "__percpu_arg(0)		\
224 		    : "+m" (var));			\
225 		break;					\
226 	case 8:						\
227 		asm(op "q "__percpu_arg(0)		\
228 		    : "+m" (var));			\
229 		break;					\
230 	default: __bad_percpu_size();			\
231 	}						\
232 })
233 
234 /*
235  * Add return operation
236  */
237 #define percpu_add_return_op(var, val)					\
238 ({									\
239 	typeof(var) paro_ret__ = val;					\
240 	switch (sizeof(var)) {						\
241 	case 1:								\
242 		asm("xaddb %0, "__percpu_arg(1)				\
243 			    : "+q" (paro_ret__), "+m" (var)		\
244 			    : : "memory");				\
245 		break;							\
246 	case 2:								\
247 		asm("xaddw %0, "__percpu_arg(1)				\
248 			    : "+r" (paro_ret__), "+m" (var)		\
249 			    : : "memory");				\
250 		break;							\
251 	case 4:								\
252 		asm("xaddl %0, "__percpu_arg(1)				\
253 			    : "+r" (paro_ret__), "+m" (var)		\
254 			    : : "memory");				\
255 		break;							\
256 	case 8:								\
257 		asm("xaddq %0, "__percpu_arg(1)				\
258 			    : "+re" (paro_ret__), "+m" (var)		\
259 			    : : "memory");				\
260 		break;							\
261 	default: __bad_percpu_size();					\
262 	}								\
263 	paro_ret__ += val;						\
264 	paro_ret__;							\
265 })
266 
267 /*
268  * xchg is implemented using cmpxchg without a lock prefix. xchg is
269  * expensive due to the implied lock prefix.  The processor cannot prefetch
270  * cachelines if xchg is used.
271  */
272 #define percpu_xchg_op(var, nval)					\
273 ({									\
274 	typeof(var) pxo_ret__;						\
275 	typeof(var) pxo_new__ = (nval);					\
276 	switch (sizeof(var)) {						\
277 	case 1:								\
278 		asm("\n\tmov "__percpu_arg(1)",%%al"			\
279 		    "\n1:\tcmpxchgb %2, "__percpu_arg(1)		\
280 		    "\n\tjnz 1b"					\
281 			    : "=&a" (pxo_ret__), "+m" (var)		\
282 			    : "q" (pxo_new__)				\
283 			    : "memory");				\
284 		break;							\
285 	case 2:								\
286 		asm("\n\tmov "__percpu_arg(1)",%%ax"			\
287 		    "\n1:\tcmpxchgw %2, "__percpu_arg(1)		\
288 		    "\n\tjnz 1b"					\
289 			    : "=&a" (pxo_ret__), "+m" (var)		\
290 			    : "r" (pxo_new__)				\
291 			    : "memory");				\
292 		break;							\
293 	case 4:								\
294 		asm("\n\tmov "__percpu_arg(1)",%%eax"			\
295 		    "\n1:\tcmpxchgl %2, "__percpu_arg(1)		\
296 		    "\n\tjnz 1b"					\
297 			    : "=&a" (pxo_ret__), "+m" (var)		\
298 			    : "r" (pxo_new__)				\
299 			    : "memory");				\
300 		break;							\
301 	case 8:								\
302 		asm("\n\tmov "__percpu_arg(1)",%%rax"			\
303 		    "\n1:\tcmpxchgq %2, "__percpu_arg(1)		\
304 		    "\n\tjnz 1b"					\
305 			    : "=&a" (pxo_ret__), "+m" (var)		\
306 			    : "r" (pxo_new__)				\
307 			    : "memory");				\
308 		break;							\
309 	default: __bad_percpu_size();					\
310 	}								\
311 	pxo_ret__;							\
312 })
313 
314 /*
315  * cmpxchg has no such implied lock semantics as a result it is much
316  * more efficient for cpu local operations.
317  */
318 #define percpu_cmpxchg_op(var, oval, nval)				\
319 ({									\
320 	typeof(var) pco_ret__;						\
321 	typeof(var) pco_old__ = (oval);					\
322 	typeof(var) pco_new__ = (nval);					\
323 	switch (sizeof(var)) {						\
324 	case 1:								\
325 		asm("cmpxchgb %2, "__percpu_arg(1)			\
326 			    : "=a" (pco_ret__), "+m" (var)		\
327 			    : "q" (pco_new__), "0" (pco_old__)		\
328 			    : "memory");				\
329 		break;							\
330 	case 2:								\
331 		asm("cmpxchgw %2, "__percpu_arg(1)			\
332 			    : "=a" (pco_ret__), "+m" (var)		\
333 			    : "r" (pco_new__), "0" (pco_old__)		\
334 			    : "memory");				\
335 		break;							\
336 	case 4:								\
337 		asm("cmpxchgl %2, "__percpu_arg(1)			\
338 			    : "=a" (pco_ret__), "+m" (var)		\
339 			    : "r" (pco_new__), "0" (pco_old__)		\
340 			    : "memory");				\
341 		break;							\
342 	case 8:								\
343 		asm("cmpxchgq %2, "__percpu_arg(1)			\
344 			    : "=a" (pco_ret__), "+m" (var)		\
345 			    : "r" (pco_new__), "0" (pco_old__)		\
346 			    : "memory");				\
347 		break;							\
348 	default: __bad_percpu_size();					\
349 	}								\
350 	pco_ret__;							\
351 })
352 
353 /*
354  * this_cpu_read() makes gcc load the percpu variable every time it is
355  * accessed while this_cpu_read_stable() allows the value to be cached.
356  * this_cpu_read_stable() is more efficient and can be used if its value
357  * is guaranteed to be valid across cpus.  The current users include
358  * get_current() and get_thread_info() both of which are actually
359  * per-thread variables implemented as per-cpu variables and thus
360  * stable for the duration of the respective task.
361  */
362 #define this_cpu_read_stable(var)	percpu_from_op("mov", var, "p" (&(var)))
363 
364 #define raw_cpu_read_1(pcp)		percpu_from_op("mov", (pcp), "m"(pcp))
365 #define raw_cpu_read_2(pcp)		percpu_from_op("mov", (pcp), "m"(pcp))
366 #define raw_cpu_read_4(pcp)		percpu_from_op("mov", (pcp), "m"(pcp))
367 
368 #define raw_cpu_write_1(pcp, val)	percpu_to_op("mov", (pcp), val)
369 #define raw_cpu_write_2(pcp, val)	percpu_to_op("mov", (pcp), val)
370 #define raw_cpu_write_4(pcp, val)	percpu_to_op("mov", (pcp), val)
371 #define raw_cpu_add_1(pcp, val)		percpu_add_op((pcp), val)
372 #define raw_cpu_add_2(pcp, val)		percpu_add_op((pcp), val)
373 #define raw_cpu_add_4(pcp, val)		percpu_add_op((pcp), val)
374 #define raw_cpu_and_1(pcp, val)		percpu_to_op("and", (pcp), val)
375 #define raw_cpu_and_2(pcp, val)		percpu_to_op("and", (pcp), val)
376 #define raw_cpu_and_4(pcp, val)		percpu_to_op("and", (pcp), val)
377 #define raw_cpu_or_1(pcp, val)		percpu_to_op("or", (pcp), val)
378 #define raw_cpu_or_2(pcp, val)		percpu_to_op("or", (pcp), val)
379 #define raw_cpu_or_4(pcp, val)		percpu_to_op("or", (pcp), val)
380 #define raw_cpu_xchg_1(pcp, val)	percpu_xchg_op(pcp, val)
381 #define raw_cpu_xchg_2(pcp, val)	percpu_xchg_op(pcp, val)
382 #define raw_cpu_xchg_4(pcp, val)	percpu_xchg_op(pcp, val)
383 
384 #define this_cpu_read_1(pcp)		percpu_from_op("mov", (pcp), "m"(pcp))
385 #define this_cpu_read_2(pcp)		percpu_from_op("mov", (pcp), "m"(pcp))
386 #define this_cpu_read_4(pcp)		percpu_from_op("mov", (pcp), "m"(pcp))
387 #define this_cpu_write_1(pcp, val)	percpu_to_op("mov", (pcp), val)
388 #define this_cpu_write_2(pcp, val)	percpu_to_op("mov", (pcp), val)
389 #define this_cpu_write_4(pcp, val)	percpu_to_op("mov", (pcp), val)
390 #define this_cpu_add_1(pcp, val)	percpu_add_op((pcp), val)
391 #define this_cpu_add_2(pcp, val)	percpu_add_op((pcp), val)
392 #define this_cpu_add_4(pcp, val)	percpu_add_op((pcp), val)
393 #define this_cpu_and_1(pcp, val)	percpu_to_op("and", (pcp), val)
394 #define this_cpu_and_2(pcp, val)	percpu_to_op("and", (pcp), val)
395 #define this_cpu_and_4(pcp, val)	percpu_to_op("and", (pcp), val)
396 #define this_cpu_or_1(pcp, val)		percpu_to_op("or", (pcp), val)
397 #define this_cpu_or_2(pcp, val)		percpu_to_op("or", (pcp), val)
398 #define this_cpu_or_4(pcp, val)		percpu_to_op("or", (pcp), val)
399 #define this_cpu_xchg_1(pcp, nval)	percpu_xchg_op(pcp, nval)
400 #define this_cpu_xchg_2(pcp, nval)	percpu_xchg_op(pcp, nval)
401 #define this_cpu_xchg_4(pcp, nval)	percpu_xchg_op(pcp, nval)
402 
403 #define raw_cpu_add_return_1(pcp, val)		percpu_add_return_op(pcp, val)
404 #define raw_cpu_add_return_2(pcp, val)		percpu_add_return_op(pcp, val)
405 #define raw_cpu_add_return_4(pcp, val)		percpu_add_return_op(pcp, val)
406 #define raw_cpu_cmpxchg_1(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
407 #define raw_cpu_cmpxchg_2(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
408 #define raw_cpu_cmpxchg_4(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
409 
410 #define this_cpu_add_return_1(pcp, val)		percpu_add_return_op(pcp, val)
411 #define this_cpu_add_return_2(pcp, val)		percpu_add_return_op(pcp, val)
412 #define this_cpu_add_return_4(pcp, val)		percpu_add_return_op(pcp, val)
413 #define this_cpu_cmpxchg_1(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
414 #define this_cpu_cmpxchg_2(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
415 #define this_cpu_cmpxchg_4(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
416 
417 #ifdef CONFIG_X86_CMPXCHG64
418 #define percpu_cmpxchg8b_double(pcp1, pcp2, o1, o2, n1, n2)		\
419 ({									\
420 	bool __ret;							\
421 	typeof(pcp1) __o1 = (o1), __n1 = (n1);				\
422 	typeof(pcp2) __o2 = (o2), __n2 = (n2);				\
423 	asm volatile("cmpxchg8b "__percpu_arg(1)"\n\tsetz %0\n\t"	\
424 		    : "=a" (__ret), "+m" (pcp1), "+m" (pcp2), "+d" (__o2) \
425 		    :  "b" (__n1), "c" (__n2), "a" (__o1));		\
426 	__ret;								\
427 })
428 
429 #define raw_cpu_cmpxchg_double_4	percpu_cmpxchg8b_double
430 #define this_cpu_cmpxchg_double_4	percpu_cmpxchg8b_double
431 #endif /* CONFIG_X86_CMPXCHG64 */
432 
433 /*
434  * Per cpu atomic 64 bit operations are only available under 64 bit.
435  * 32 bit must fall back to generic operations.
436  */
437 #ifdef CONFIG_X86_64
438 #define raw_cpu_read_8(pcp)			percpu_from_op("mov", (pcp), "m"(pcp))
439 #define raw_cpu_write_8(pcp, val)		percpu_to_op("mov", (pcp), val)
440 #define raw_cpu_add_8(pcp, val)			percpu_add_op((pcp), val)
441 #define raw_cpu_and_8(pcp, val)			percpu_to_op("and", (pcp), val)
442 #define raw_cpu_or_8(pcp, val)			percpu_to_op("or", (pcp), val)
443 #define raw_cpu_add_return_8(pcp, val)		percpu_add_return_op(pcp, val)
444 #define raw_cpu_xchg_8(pcp, nval)		percpu_xchg_op(pcp, nval)
445 #define raw_cpu_cmpxchg_8(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
446 
447 #define this_cpu_read_8(pcp)			percpu_from_op("mov", (pcp), "m"(pcp))
448 #define this_cpu_write_8(pcp, val)		percpu_to_op("mov", (pcp), val)
449 #define this_cpu_add_8(pcp, val)		percpu_add_op((pcp), val)
450 #define this_cpu_and_8(pcp, val)		percpu_to_op("and", (pcp), val)
451 #define this_cpu_or_8(pcp, val)			percpu_to_op("or", (pcp), val)
452 #define this_cpu_add_return_8(pcp, val)		percpu_add_return_op(pcp, val)
453 #define this_cpu_xchg_8(pcp, nval)		percpu_xchg_op(pcp, nval)
454 #define this_cpu_cmpxchg_8(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
455 
456 /*
457  * Pretty complex macro to generate cmpxchg16 instruction.  The instruction
458  * is not supported on early AMD64 processors so we must be able to emulate
459  * it in software.  The address used in the cmpxchg16 instruction must be
460  * aligned to a 16 byte boundary.
461  */
462 #define percpu_cmpxchg16b_double(pcp1, pcp2, o1, o2, n1, n2)		\
463 ({									\
464 	bool __ret;							\
465 	typeof(pcp1) __o1 = (o1), __n1 = (n1);				\
466 	typeof(pcp2) __o2 = (o2), __n2 = (n2);				\
467 	alternative_io("leaq %P1,%%rsi\n\tcall this_cpu_cmpxchg16b_emu\n\t", \
468 		       "cmpxchg16b " __percpu_arg(1) "\n\tsetz %0\n\t",	\
469 		       X86_FEATURE_CX16,				\
470 		       ASM_OUTPUT2("=a" (__ret), "+m" (pcp1),		\
471 				   "+m" (pcp2), "+d" (__o2)),		\
472 		       "b" (__n1), "c" (__n2), "a" (__o1) : "rsi");	\
473 	__ret;								\
474 })
475 
476 #define raw_cpu_cmpxchg_double_8	percpu_cmpxchg16b_double
477 #define this_cpu_cmpxchg_double_8	percpu_cmpxchg16b_double
478 
479 #endif
480 
481 /* This is not atomic against other CPUs -- CPU preemption needs to be off */
482 #define x86_test_and_clear_bit_percpu(bit, var)				\
483 ({									\
484 	int old__;							\
485 	asm volatile("btr %2,"__percpu_arg(1)"\n\tsbbl %0,%0"		\
486 		     : "=r" (old__), "+m" (var)				\
487 		     : "dIr" (bit));					\
488 	old__;								\
489 })
490 
491 static __always_inline int x86_this_cpu_constant_test_bit(unsigned int nr,
492                         const unsigned long __percpu *addr)
493 {
494 	unsigned long __percpu *a = (unsigned long *)addr + nr / BITS_PER_LONG;
495 
496 #ifdef CONFIG_X86_64
497 	return ((1UL << (nr % BITS_PER_LONG)) & raw_cpu_read_8(*a)) != 0;
498 #else
499 	return ((1UL << (nr % BITS_PER_LONG)) & raw_cpu_read_4(*a)) != 0;
500 #endif
501 }
502 
503 static inline int x86_this_cpu_variable_test_bit(int nr,
504                         const unsigned long __percpu *addr)
505 {
506 	int oldbit;
507 
508 	asm volatile("bt "__percpu_arg(2)",%1\n\t"
509 			"sbb %0,%0"
510 			: "=r" (oldbit)
511 			: "m" (*(unsigned long *)addr), "Ir" (nr));
512 
513 	return oldbit;
514 }
515 
516 #define x86_this_cpu_test_bit(nr, addr)			\
517 	(__builtin_constant_p((nr))			\
518 	 ? x86_this_cpu_constant_test_bit((nr), (addr))	\
519 	 : x86_this_cpu_variable_test_bit((nr), (addr)))
520 
521 
522 #include <asm-generic/percpu.h>
523 
524 /* We can use this directly for local CPU (faster). */
525 DECLARE_PER_CPU(unsigned long, this_cpu_off);
526 
527 #endif /* !__ASSEMBLY__ */
528 
529 #ifdef CONFIG_SMP
530 
531 /*
532  * Define the "EARLY_PER_CPU" macros.  These are used for some per_cpu
533  * variables that are initialized and accessed before there are per_cpu
534  * areas allocated.
535  */
536 
537 #define	DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)			\
538 	DEFINE_PER_CPU(_type, _name) = _initvalue;			\
539 	__typeof__(_type) _name##_early_map[NR_CPUS] __initdata =	\
540 				{ [0 ... NR_CPUS-1] = _initvalue };	\
541 	__typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
542 
543 #define DEFINE_EARLY_PER_CPU_READ_MOSTLY(_type, _name, _initvalue)	\
544 	DEFINE_PER_CPU_READ_MOSTLY(_type, _name) = _initvalue;		\
545 	__typeof__(_type) _name##_early_map[NR_CPUS] __initdata =	\
546 				{ [0 ... NR_CPUS-1] = _initvalue };	\
547 	__typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
548 
549 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name)			\
550 	EXPORT_PER_CPU_SYMBOL(_name)
551 
552 #define DECLARE_EARLY_PER_CPU(_type, _name)			\
553 	DECLARE_PER_CPU(_type, _name);				\
554 	extern __typeof__(_type) *_name##_early_ptr;		\
555 	extern __typeof__(_type)  _name##_early_map[]
556 
557 #define DECLARE_EARLY_PER_CPU_READ_MOSTLY(_type, _name)		\
558 	DECLARE_PER_CPU_READ_MOSTLY(_type, _name);		\
559 	extern __typeof__(_type) *_name##_early_ptr;		\
560 	extern __typeof__(_type)  _name##_early_map[]
561 
562 #define	early_per_cpu_ptr(_name) (_name##_early_ptr)
563 #define	early_per_cpu_map(_name, _idx) (_name##_early_map[_idx])
564 #define	early_per_cpu(_name, _cpu) 				\
565 	*(early_per_cpu_ptr(_name) ?				\
566 		&early_per_cpu_ptr(_name)[_cpu] :		\
567 		&per_cpu(_name, _cpu))
568 
569 #else	/* !CONFIG_SMP */
570 #define	DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)		\
571 	DEFINE_PER_CPU(_type, _name) = _initvalue
572 
573 #define DEFINE_EARLY_PER_CPU_READ_MOSTLY(_type, _name, _initvalue)	\
574 	DEFINE_PER_CPU_READ_MOSTLY(_type, _name) = _initvalue
575 
576 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name)			\
577 	EXPORT_PER_CPU_SYMBOL(_name)
578 
579 #define DECLARE_EARLY_PER_CPU(_type, _name)			\
580 	DECLARE_PER_CPU(_type, _name)
581 
582 #define DECLARE_EARLY_PER_CPU_READ_MOSTLY(_type, _name)		\
583 	DECLARE_PER_CPU_READ_MOSTLY(_type, _name)
584 
585 #define	early_per_cpu(_name, _cpu) per_cpu(_name, _cpu)
586 #define	early_per_cpu_ptr(_name) NULL
587 /* no early_per_cpu_map() */
588 
589 #endif	/* !CONFIG_SMP */
590 
591 #endif /* _ASM_X86_PERCPU_H */
592