1 #ifndef _ASM_X86_PERCPU_H
2 #define _ASM_X86_PERCPU_H
5 #define __percpu_seg gs
6 #define __percpu_mov_op movq
8 #define __percpu_seg fs
9 #define __percpu_mov_op movl
15 * PER_CPU finds an address of a per-cpu variable.
19 * reg - 32bit register
21 * The resulting address is stored in the "reg" argument.
24 * PER_CPU(cpu_gdt_descr, %ebx)
27 #define PER_CPU(var, reg) \
28 __percpu_mov_op %__percpu_seg:this_cpu_off, reg; \
30 #define PER_CPU_VAR(var) %__percpu_seg:var
32 #define PER_CPU(var, reg) __percpu_mov_op $var, reg
33 #define PER_CPU_VAR(var) var
36 #ifdef CONFIG_X86_64_SMP
37 #define INIT_PER_CPU_VAR(var) init_per_cpu__##var
39 #define INIT_PER_CPU_VAR(var) var
42 #else /* ...!ASSEMBLY */
44 #include <linux/kernel.h>
45 #include <linux/stringify.h>
48 #define __percpu_arg(x) "%%"__stringify(__percpu_seg)":%P" #x
49 #define __my_cpu_offset percpu_read(this_cpu_off)
52 * Compared to the generic __my_cpu_offset version, the following
53 * saves one instruction and avoids clobbering a temp register.
55 #define __this_cpu_ptr(ptr) \
57 unsigned long tcp_ptr__; \
58 __verify_pcpu_ptr(ptr); \
59 asm volatile("add " __percpu_arg(1) ", %0" \
61 : "m" (this_cpu_off), "0" (ptr)); \
62 (typeof(*(ptr)) __kernel __force *)tcp_ptr__; \
65 #define __percpu_arg(x) "%P" #x
69 * Initialized pointers to per-cpu variables needed for the boot
70 * processor need to use these macros to get the proper address
71 * offset from __per_cpu_load on SMP.
73 * There also must be an entry in vmlinux_64.lds.S
75 #define DECLARE_INIT_PER_CPU(var) \
76 extern typeof(var) init_per_cpu_var(var)
78 #ifdef CONFIG_X86_64_SMP
79 #define init_per_cpu_var(var) init_per_cpu__##var
81 #define init_per_cpu_var(var) var
84 /* For arch-specific code, we can use direct single-insn ops (they
85 * don't give an lvalue though). */
86 extern void __bad_percpu_size(void);
88 #define percpu_to_op(op, var, val) \
90 typedef typeof(var) pto_T__; \
96 switch (sizeof(var)) { \
98 asm(op "b %1,"__percpu_arg(0) \
100 : "qi" ((pto_T__)(val))); \
103 asm(op "w %1,"__percpu_arg(0) \
105 : "ri" ((pto_T__)(val))); \
108 asm(op "l %1,"__percpu_arg(0) \
110 : "ri" ((pto_T__)(val))); \
113 asm(op "q %1,"__percpu_arg(0) \
115 : "re" ((pto_T__)(val))); \
117 default: __bad_percpu_size(); \
122 * Generate a percpu add to memory instruction and optimize code
123 * if one is added or subtracted.
125 #define percpu_add_op(var, val) \
127 typedef typeof(var) pao_T__; \
128 const int pao_ID__ = (__builtin_constant_p(val) && \
129 ((val) == 1 || (val) == -1)) ? (val) : 0; \
135 switch (sizeof(var)) { \
138 asm("incb "__percpu_arg(0) : "+m" (var)); \
139 else if (pao_ID__ == -1) \
140 asm("decb "__percpu_arg(0) : "+m" (var)); \
142 asm("addb %1, "__percpu_arg(0) \
144 : "qi" ((pao_T__)(val))); \
148 asm("incw "__percpu_arg(0) : "+m" (var)); \
149 else if (pao_ID__ == -1) \
150 asm("decw "__percpu_arg(0) : "+m" (var)); \
152 asm("addw %1, "__percpu_arg(0) \
154 : "ri" ((pao_T__)(val))); \
158 asm("incl "__percpu_arg(0) : "+m" (var)); \
159 else if (pao_ID__ == -1) \
160 asm("decl "__percpu_arg(0) : "+m" (var)); \
162 asm("addl %1, "__percpu_arg(0) \
164 : "ri" ((pao_T__)(val))); \
168 asm("incq "__percpu_arg(0) : "+m" (var)); \
169 else if (pao_ID__ == -1) \
170 asm("decq "__percpu_arg(0) : "+m" (var)); \
172 asm("addq %1, "__percpu_arg(0) \
174 : "re" ((pao_T__)(val))); \
176 default: __bad_percpu_size(); \
180 #define percpu_from_op(op, var, constraint) \
182 typeof(var) pfo_ret__; \
183 switch (sizeof(var)) { \
185 asm(op "b "__percpu_arg(1)",%0" \
190 asm(op "w "__percpu_arg(1)",%0" \
195 asm(op "l "__percpu_arg(1)",%0" \
200 asm(op "q "__percpu_arg(1)",%0" \
204 default: __bad_percpu_size(); \
209 #define percpu_unary_op(op, var) \
211 switch (sizeof(var)) { \
213 asm(op "b "__percpu_arg(0) \
217 asm(op "w "__percpu_arg(0) \
221 asm(op "l "__percpu_arg(0) \
225 asm(op "q "__percpu_arg(0) \
228 default: __bad_percpu_size(); \
233 * percpu_read() makes gcc load the percpu variable every time it is
234 * accessed while percpu_read_stable() allows the value to be cached.
235 * percpu_read_stable() is more efficient and can be used if its value
236 * is guaranteed to be valid across cpus. The current users include
237 * get_current() and get_thread_info() both of which are actually
238 * per-thread variables implemented as per-cpu variables and thus
239 * stable for the duration of the respective task.
241 #define percpu_read(var) percpu_from_op("mov", var, "m" (var))
242 #define percpu_read_stable(var) percpu_from_op("mov", var, "p" (&(var)))
243 #define percpu_write(var, val) percpu_to_op("mov", var, val)
244 #define percpu_add(var, val) percpu_add_op(var, val)
245 #define percpu_sub(var, val) percpu_add_op(var, -(val))
246 #define percpu_and(var, val) percpu_to_op("and", var, val)
247 #define percpu_or(var, val) percpu_to_op("or", var, val)
248 #define percpu_xor(var, val) percpu_to_op("xor", var, val)
249 #define percpu_inc(var) percpu_unary_op("inc", var)
251 #define __this_cpu_read_1(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
252 #define __this_cpu_read_2(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
253 #define __this_cpu_read_4(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
255 #define __this_cpu_write_1(pcp, val) percpu_to_op("mov", (pcp), val)
256 #define __this_cpu_write_2(pcp, val) percpu_to_op("mov", (pcp), val)
257 #define __this_cpu_write_4(pcp, val) percpu_to_op("mov", (pcp), val)
258 #define __this_cpu_add_1(pcp, val) percpu_add_op((pcp), val)
259 #define __this_cpu_add_2(pcp, val) percpu_add_op((pcp), val)
260 #define __this_cpu_add_4(pcp, val) percpu_add_op((pcp), val)
261 #define __this_cpu_and_1(pcp, val) percpu_to_op("and", (pcp), val)
262 #define __this_cpu_and_2(pcp, val) percpu_to_op("and", (pcp), val)
263 #define __this_cpu_and_4(pcp, val) percpu_to_op("and", (pcp), val)
264 #define __this_cpu_or_1(pcp, val) percpu_to_op("or", (pcp), val)
265 #define __this_cpu_or_2(pcp, val) percpu_to_op("or", (pcp), val)
266 #define __this_cpu_or_4(pcp, val) percpu_to_op("or", (pcp), val)
267 #define __this_cpu_xor_1(pcp, val) percpu_to_op("xor", (pcp), val)
268 #define __this_cpu_xor_2(pcp, val) percpu_to_op("xor", (pcp), val)
269 #define __this_cpu_xor_4(pcp, val) percpu_to_op("xor", (pcp), val)
271 #define this_cpu_read_1(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
272 #define this_cpu_read_2(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
273 #define this_cpu_read_4(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
274 #define this_cpu_write_1(pcp, val) percpu_to_op("mov", (pcp), val)
275 #define this_cpu_write_2(pcp, val) percpu_to_op("mov", (pcp), val)
276 #define this_cpu_write_4(pcp, val) percpu_to_op("mov", (pcp), val)
277 #define this_cpu_add_1(pcp, val) percpu_add_op((pcp), val)
278 #define this_cpu_add_2(pcp, val) percpu_add_op((pcp), val)
279 #define this_cpu_add_4(pcp, val) percpu_add_op((pcp), val)
280 #define this_cpu_and_1(pcp, val) percpu_to_op("and", (pcp), val)
281 #define this_cpu_and_2(pcp, val) percpu_to_op("and", (pcp), val)
282 #define this_cpu_and_4(pcp, val) percpu_to_op("and", (pcp), val)
283 #define this_cpu_or_1(pcp, val) percpu_to_op("or", (pcp), val)
284 #define this_cpu_or_2(pcp, val) percpu_to_op("or", (pcp), val)
285 #define this_cpu_or_4(pcp, val) percpu_to_op("or", (pcp), val)
286 #define this_cpu_xor_1(pcp, val) percpu_to_op("xor", (pcp), val)
287 #define this_cpu_xor_2(pcp, val) percpu_to_op("xor", (pcp), val)
288 #define this_cpu_xor_4(pcp, val) percpu_to_op("xor", (pcp), val)
290 #define irqsafe_cpu_add_1(pcp, val) percpu_add_op((pcp), val)
291 #define irqsafe_cpu_add_2(pcp, val) percpu_add_op((pcp), val)
292 #define irqsafe_cpu_add_4(pcp, val) percpu_add_op((pcp), val)
293 #define irqsafe_cpu_and_1(pcp, val) percpu_to_op("and", (pcp), val)
294 #define irqsafe_cpu_and_2(pcp, val) percpu_to_op("and", (pcp), val)
295 #define irqsafe_cpu_and_4(pcp, val) percpu_to_op("and", (pcp), val)
296 #define irqsafe_cpu_or_1(pcp, val) percpu_to_op("or", (pcp), val)
297 #define irqsafe_cpu_or_2(pcp, val) percpu_to_op("or", (pcp), val)
298 #define irqsafe_cpu_or_4(pcp, val) percpu_to_op("or", (pcp), val)
299 #define irqsafe_cpu_xor_1(pcp, val) percpu_to_op("xor", (pcp), val)
300 #define irqsafe_cpu_xor_2(pcp, val) percpu_to_op("xor", (pcp), val)
301 #define irqsafe_cpu_xor_4(pcp, val) percpu_to_op("xor", (pcp), val)
304 * Per cpu atomic 64 bit operations are only available under 64 bit.
305 * 32 bit must fall back to generic operations.
308 #define __this_cpu_read_8(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
309 #define __this_cpu_write_8(pcp, val) percpu_to_op("mov", (pcp), val)
310 #define __this_cpu_add_8(pcp, val) percpu_add_op((pcp), val)
311 #define __this_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val)
312 #define __this_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val)
313 #define __this_cpu_xor_8(pcp, val) percpu_to_op("xor", (pcp), val)
315 #define this_cpu_read_8(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
316 #define this_cpu_write_8(pcp, val) percpu_to_op("mov", (pcp), val)
317 #define this_cpu_add_8(pcp, val) percpu_add_op((pcp), val)
318 #define this_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val)
319 #define this_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val)
320 #define this_cpu_xor_8(pcp, val) percpu_to_op("xor", (pcp), val)
322 #define irqsafe_cpu_add_8(pcp, val) percpu_add_op((pcp), val)
323 #define irqsafe_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val)
324 #define irqsafe_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val)
325 #define irqsafe_cpu_xor_8(pcp, val) percpu_to_op("xor", (pcp), val)
329 /* This is not atomic against other CPUs -- CPU preemption needs to be off */
330 #define x86_test_and_clear_bit_percpu(bit, var) \
333 asm volatile("btr %2,"__percpu_arg(1)"\n\tsbbl %0,%0" \
334 : "=r" (old__), "+m" (var) \
339 #include <asm-generic/percpu.h>
341 /* We can use this directly for local CPU (faster). */
342 DECLARE_PER_CPU(unsigned long, this_cpu_off);
344 #endif /* !__ASSEMBLY__ */
349 * Define the "EARLY_PER_CPU" macros. These are used for some per_cpu
350 * variables that are initialized and accessed before there are per_cpu
354 #define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \
355 DEFINE_PER_CPU(_type, _name) = _initvalue; \
356 __typeof__(_type) _name##_early_map[NR_CPUS] __initdata = \
357 { [0 ... NR_CPUS-1] = _initvalue }; \
358 __typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
360 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name) \
361 EXPORT_PER_CPU_SYMBOL(_name)
363 #define DECLARE_EARLY_PER_CPU(_type, _name) \
364 DECLARE_PER_CPU(_type, _name); \
365 extern __typeof__(_type) *_name##_early_ptr; \
366 extern __typeof__(_type) _name##_early_map[]
368 #define early_per_cpu_ptr(_name) (_name##_early_ptr)
369 #define early_per_cpu_map(_name, _idx) (_name##_early_map[_idx])
370 #define early_per_cpu(_name, _cpu) \
371 *(early_per_cpu_ptr(_name) ? \
372 &early_per_cpu_ptr(_name)[_cpu] : \
373 &per_cpu(_name, _cpu))
375 #else /* !CONFIG_SMP */
376 #define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \
377 DEFINE_PER_CPU(_type, _name) = _initvalue
379 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name) \
380 EXPORT_PER_CPU_SYMBOL(_name)
382 #define DECLARE_EARLY_PER_CPU(_type, _name) \
383 DECLARE_PER_CPU(_type, _name)
385 #define early_per_cpu(_name, _cpu) per_cpu(_name, _cpu)
386 #define early_per_cpu_ptr(_name) NULL
387 /* no early_per_cpu_map() */
389 #endif /* !CONFIG_SMP */
391 #endif /* _ASM_X86_PERCPU_H */