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)
51 #define __percpu_arg(x) "%P" #x
55 * Initialized pointers to per-cpu variables needed for the boot
56 * processor need to use these macros to get the proper address
57 * offset from __per_cpu_load on SMP.
59 * There also must be an entry in vmlinux_64.lds.S
61 #define DECLARE_INIT_PER_CPU(var) \
62 extern typeof(var) init_per_cpu_var(var)
64 #ifdef CONFIG_X86_64_SMP
65 #define init_per_cpu_var(var) init_per_cpu__##var
67 #define init_per_cpu_var(var) var
70 /* For arch-specific code, we can use direct single-insn ops (they
71 * don't give an lvalue though). */
72 extern void __bad_percpu_size(void);
74 #define percpu_to_op(op, var, val) \
76 typedef typeof(var) pto_T__; \
81 switch (sizeof(var)) { \
83 asm(op "b %1,"__percpu_arg(0) \
85 : "qi" ((pto_T__)(val))); \
88 asm(op "w %1,"__percpu_arg(0) \
90 : "ri" ((pto_T__)(val))); \
93 asm(op "l %1,"__percpu_arg(0) \
95 : "ri" ((pto_T__)(val))); \
98 asm(op "q %1,"__percpu_arg(0) \
100 : "re" ((pto_T__)(val))); \
102 default: __bad_percpu_size(); \
106 #define percpu_from_op(op, var, constraint) \
108 typeof(var) pfo_ret__; \
109 switch (sizeof(var)) { \
111 asm(op "b "__percpu_arg(1)",%0" \
116 asm(op "w "__percpu_arg(1)",%0" \
121 asm(op "l "__percpu_arg(1)",%0" \
126 asm(op "q "__percpu_arg(1)",%0" \
130 default: __bad_percpu_size(); \
136 * percpu_read() makes gcc load the percpu variable every time it is
137 * accessed while percpu_read_stable() allows the value to be cached.
138 * percpu_read_stable() is more efficient and can be used if its value
139 * is guaranteed to be valid across cpus. The current users include
140 * get_current() and get_thread_info() both of which are actually
141 * per-thread variables implemented as per-cpu variables and thus
142 * stable for the duration of the respective task.
144 #define percpu_read(var) percpu_from_op("mov", var, "m" (var))
145 #define percpu_read_stable(var) percpu_from_op("mov", var, "p" (&(var)))
146 #define percpu_write(var, val) percpu_to_op("mov", var, val)
147 #define percpu_add(var, val) percpu_to_op("add", var, val)
148 #define percpu_sub(var, val) percpu_to_op("sub", var, val)
149 #define percpu_and(var, val) percpu_to_op("and", var, val)
150 #define percpu_or(var, val) percpu_to_op("or", var, val)
151 #define percpu_xor(var, val) percpu_to_op("xor", var, val)
153 #define __this_cpu_read_1(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
154 #define __this_cpu_read_2(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
155 #define __this_cpu_read_4(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
157 #define __this_cpu_write_1(pcp, val) percpu_to_op("mov", (pcp), val)
158 #define __this_cpu_write_2(pcp, val) percpu_to_op("mov", (pcp), val)
159 #define __this_cpu_write_4(pcp, val) percpu_to_op("mov", (pcp), val)
160 #define __this_cpu_add_1(pcp, val) percpu_to_op("add", (pcp), val)
161 #define __this_cpu_add_2(pcp, val) percpu_to_op("add", (pcp), val)
162 #define __this_cpu_add_4(pcp, val) percpu_to_op("add", (pcp), val)
163 #define __this_cpu_and_1(pcp, val) percpu_to_op("and", (pcp), val)
164 #define __this_cpu_and_2(pcp, val) percpu_to_op("and", (pcp), val)
165 #define __this_cpu_and_4(pcp, val) percpu_to_op("and", (pcp), val)
166 #define __this_cpu_or_1(pcp, val) percpu_to_op("or", (pcp), val)
167 #define __this_cpu_or_2(pcp, val) percpu_to_op("or", (pcp), val)
168 #define __this_cpu_or_4(pcp, val) percpu_to_op("or", (pcp), val)
169 #define __this_cpu_xor_1(pcp, val) percpu_to_op("xor", (pcp), val)
170 #define __this_cpu_xor_2(pcp, val) percpu_to_op("xor", (pcp), val)
171 #define __this_cpu_xor_4(pcp, val) percpu_to_op("xor", (pcp), val)
173 #define this_cpu_read_1(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
174 #define this_cpu_read_2(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
175 #define this_cpu_read_4(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
176 #define this_cpu_write_1(pcp, val) percpu_to_op("mov", (pcp), val)
177 #define this_cpu_write_2(pcp, val) percpu_to_op("mov", (pcp), val)
178 #define this_cpu_write_4(pcp, val) percpu_to_op("mov", (pcp), val)
179 #define this_cpu_add_1(pcp, val) percpu_to_op("add", (pcp), val)
180 #define this_cpu_add_2(pcp, val) percpu_to_op("add", (pcp), val)
181 #define this_cpu_add_4(pcp, val) percpu_to_op("add", (pcp), val)
182 #define this_cpu_and_1(pcp, val) percpu_to_op("and", (pcp), val)
183 #define this_cpu_and_2(pcp, val) percpu_to_op("and", (pcp), val)
184 #define this_cpu_and_4(pcp, val) percpu_to_op("and", (pcp), val)
185 #define this_cpu_or_1(pcp, val) percpu_to_op("or", (pcp), val)
186 #define this_cpu_or_2(pcp, val) percpu_to_op("or", (pcp), val)
187 #define this_cpu_or_4(pcp, val) percpu_to_op("or", (pcp), val)
188 #define this_cpu_xor_1(pcp, val) percpu_to_op("xor", (pcp), val)
189 #define this_cpu_xor_2(pcp, val) percpu_to_op("xor", (pcp), val)
190 #define this_cpu_xor_4(pcp, val) percpu_to_op("xor", (pcp), val)
192 #define irqsafe_cpu_add_1(pcp, val) percpu_to_op("add", (pcp), val)
193 #define irqsafe_cpu_add_2(pcp, val) percpu_to_op("add", (pcp), val)
194 #define irqsafe_cpu_add_4(pcp, val) percpu_to_op("add", (pcp), val)
195 #define irqsafe_cpu_and_1(pcp, val) percpu_to_op("and", (pcp), val)
196 #define irqsafe_cpu_and_2(pcp, val) percpu_to_op("and", (pcp), val)
197 #define irqsafe_cpu_and_4(pcp, val) percpu_to_op("and", (pcp), val)
198 #define irqsafe_cpu_or_1(pcp, val) percpu_to_op("or", (pcp), val)
199 #define irqsafe_cpu_or_2(pcp, val) percpu_to_op("or", (pcp), val)
200 #define irqsafe_cpu_or_4(pcp, val) percpu_to_op("or", (pcp), val)
201 #define irqsafe_cpu_xor_1(pcp, val) percpu_to_op("xor", (pcp), val)
202 #define irqsafe_cpu_xor_2(pcp, val) percpu_to_op("xor", (pcp), val)
203 #define irqsafe_cpu_xor_4(pcp, val) percpu_to_op("xor", (pcp), val)
206 * Per cpu atomic 64 bit operations are only available under 64 bit.
207 * 32 bit must fall back to generic operations.
210 #define __this_cpu_read_8(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
211 #define __this_cpu_write_8(pcp, val) percpu_to_op("mov", (pcp), val)
212 #define __this_cpu_add_8(pcp, val) percpu_to_op("add", (pcp), val)
213 #define __this_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val)
214 #define __this_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val)
215 #define __this_cpu_xor_8(pcp, val) percpu_to_op("xor", (pcp), val)
217 #define this_cpu_read_8(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
218 #define this_cpu_write_8(pcp, val) percpu_to_op("mov", (pcp), val)
219 #define this_cpu_add_8(pcp, val) percpu_to_op("add", (pcp), val)
220 #define this_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val)
221 #define this_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val)
222 #define this_cpu_xor_8(pcp, val) percpu_to_op("xor", (pcp), val)
224 #define irqsafe_cpu_add_8(pcp, val) percpu_to_op("add", (pcp), val)
225 #define irqsafe_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val)
226 #define irqsafe_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val)
227 #define irqsafe_cpu_xor_8(pcp, val) percpu_to_op("xor", (pcp), val)
231 /* This is not atomic against other CPUs -- CPU preemption needs to be off */
232 #define x86_test_and_clear_bit_percpu(bit, var) \
235 asm volatile("btr %2,"__percpu_arg(1)"\n\tsbbl %0,%0" \
236 : "=r" (old__), "+m" (var) \
241 #include <asm-generic/percpu.h>
243 /* We can use this directly for local CPU (faster). */
244 DECLARE_PER_CPU(unsigned long, this_cpu_off
);
246 #endif /* !__ASSEMBLY__ */
251 * Define the "EARLY_PER_CPU" macros. These are used for some per_cpu
252 * variables that are initialized and accessed before there are per_cpu
256 #define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \
257 DEFINE_PER_CPU(_type, _name) = _initvalue; \
258 __typeof__(_type) _name##_early_map[NR_CPUS] __initdata = \
259 { [0 ... NR_CPUS-1] = _initvalue }; \
260 __typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
262 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name) \
263 EXPORT_PER_CPU_SYMBOL(_name)
265 #define DECLARE_EARLY_PER_CPU(_type, _name) \
266 DECLARE_PER_CPU(_type, _name); \
267 extern __typeof__(_type) *_name##_early_ptr; \
268 extern __typeof__(_type) _name##_early_map[]
270 #define early_per_cpu_ptr(_name) (_name##_early_ptr)
271 #define early_per_cpu_map(_name, _idx) (_name##_early_map[_idx])
272 #define early_per_cpu(_name, _cpu) \
273 *(early_per_cpu_ptr(_name) ? \
274 &early_per_cpu_ptr(_name)[_cpu] : \
275 &per_cpu(_name, _cpu))
277 #else /* !CONFIG_SMP */
278 #define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \
279 DEFINE_PER_CPU(_type, _name) = _initvalue
281 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name) \
282 EXPORT_PER_CPU_SYMBOL(_name)
284 #define DECLARE_EARLY_PER_CPU(_type, _name) \
285 DECLARE_PER_CPU(_type, _name)
287 #define early_per_cpu(_name, _cpu) per_cpu(_name, _cpu)
288 #define early_per_cpu_ptr(_name) NULL
289 /* no early_per_cpu_map() */
291 #endif /* !CONFIG_SMP */
293 #endif /* _ASM_X86_PERCPU_H */