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Linux kernel mirror (for testing)
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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:per_cpu__this_cpu_off, reg; \
29 lea per_cpu__##var(reg), reg
30#define PER_CPU_VAR(var) %__percpu_seg:per_cpu__##var
31#else /* ! SMP */
32#define PER_CPU(var, reg) \
33 __percpu_mov_op $per_cpu__##var, reg
34#define PER_CPU_VAR(var) per_cpu__##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) per_cpu__##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_arg(x) "%%"__stringify(__percpu_seg)":%P" #x
50#define __my_cpu_offset percpu_read(this_cpu_off)
51#else
52#define __percpu_arg(x) "%" #x
53#endif
54
55/*
56 * Initialized pointers to per-cpu variables needed for the boot
57 * processor need to use these macros to get the proper address
58 * offset from __per_cpu_load on SMP.
59 *
60 * There also must be an entry in vmlinux_64.lds.S
61 */
62#define DECLARE_INIT_PER_CPU(var) \
63 extern typeof(per_cpu_var(var)) init_per_cpu_var(var)
64
65#ifdef CONFIG_X86_64_SMP
66#define init_per_cpu_var(var) init_per_cpu__##var
67#else
68#define init_per_cpu_var(var) per_cpu_var(var)
69#endif
70
71/* For arch-specific code, we can use direct single-insn ops (they
72 * don't give an lvalue though). */
73extern void __bad_percpu_size(void);
74
75#define percpu_to_op(op, var, val) \
76do { \
77 typedef typeof(var) T__; \
78 if (0) { \
79 T__ tmp__; \
80 tmp__ = (val); \
81 } \
82 switch (sizeof(var)) { \
83 case 1: \
84 asm(op "b %1,"__percpu_arg(0) \
85 : "+m" (var) \
86 : "qi" ((T__)(val))); \
87 break; \
88 case 2: \
89 asm(op "w %1,"__percpu_arg(0) \
90 : "+m" (var) \
91 : "ri" ((T__)(val))); \
92 break; \
93 case 4: \
94 asm(op "l %1,"__percpu_arg(0) \
95 : "+m" (var) \
96 : "ri" ((T__)(val))); \
97 break; \
98 case 8: \
99 asm(op "q %1,"__percpu_arg(0) \
100 : "+m" (var) \
101 : "re" ((T__)(val))); \
102 break; \
103 default: __bad_percpu_size(); \
104 } \
105} while (0)
106
107#define percpu_from_op(op, var) \
108({ \
109 typeof(var) ret__; \
110 switch (sizeof(var)) { \
111 case 1: \
112 asm(op "b "__percpu_arg(1)",%0" \
113 : "=q" (ret__) \
114 : "m" (var)); \
115 break; \
116 case 2: \
117 asm(op "w "__percpu_arg(1)",%0" \
118 : "=r" (ret__) \
119 : "m" (var)); \
120 break; \
121 case 4: \
122 asm(op "l "__percpu_arg(1)",%0" \
123 : "=r" (ret__) \
124 : "m" (var)); \
125 break; \
126 case 8: \
127 asm(op "q "__percpu_arg(1)",%0" \
128 : "=r" (ret__) \
129 : "m" (var)); \
130 break; \
131 default: __bad_percpu_size(); \
132 } \
133 ret__; \
134})
135
136#define percpu_read(var) percpu_from_op("mov", per_cpu__##var)
137#define percpu_write(var, val) percpu_to_op("mov", per_cpu__##var, val)
138#define percpu_add(var, val) percpu_to_op("add", per_cpu__##var, val)
139#define percpu_sub(var, val) percpu_to_op("sub", per_cpu__##var, val)
140#define percpu_and(var, val) percpu_to_op("and", per_cpu__##var, val)
141#define percpu_or(var, val) percpu_to_op("or", per_cpu__##var, val)
142#define percpu_xor(var, val) percpu_to_op("xor", per_cpu__##var, val)
143
144/* This is not atomic against other CPUs -- CPU preemption needs to be off */
145#define x86_test_and_clear_bit_percpu(bit, var) \
146({ \
147 int old__; \
148 asm volatile("btr %2,"__percpu_arg(1)"\n\tsbbl %0,%0" \
149 : "=r" (old__), "+m" (per_cpu__##var) \
150 : "dIr" (bit)); \
151 old__; \
152})
153
154#include <asm-generic/percpu.h>
155
156/* We can use this directly for local CPU (faster). */
157DECLARE_PER_CPU(unsigned long, this_cpu_off);
158
159#ifdef CONFIG_NEED_MULTIPLE_NODES
160void *pcpu_lpage_remapped(void *kaddr);
161#else
162static inline void *pcpu_lpage_remapped(void *kaddr)
163{
164 return NULL;
165}
166#endif
167
168#endif /* !__ASSEMBLY__ */
169
170#ifdef CONFIG_SMP
171
172/*
173 * Define the "EARLY_PER_CPU" macros. These are used for some per_cpu
174 * variables that are initialized and accessed before there are per_cpu
175 * areas allocated.
176 */
177
178#define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \
179 DEFINE_PER_CPU(_type, _name) = _initvalue; \
180 __typeof__(_type) _name##_early_map[NR_CPUS] __initdata = \
181 { [0 ... NR_CPUS-1] = _initvalue }; \
182 __typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
183
184#define EXPORT_EARLY_PER_CPU_SYMBOL(_name) \
185 EXPORT_PER_CPU_SYMBOL(_name)
186
187#define DECLARE_EARLY_PER_CPU(_type, _name) \
188 DECLARE_PER_CPU(_type, _name); \
189 extern __typeof__(_type) *_name##_early_ptr; \
190 extern __typeof__(_type) _name##_early_map[]
191
192#define early_per_cpu_ptr(_name) (_name##_early_ptr)
193#define early_per_cpu_map(_name, _idx) (_name##_early_map[_idx])
194#define early_per_cpu(_name, _cpu) \
195 *(early_per_cpu_ptr(_name) ? \
196 &early_per_cpu_ptr(_name)[_cpu] : \
197 &per_cpu(_name, _cpu))
198
199#else /* !CONFIG_SMP */
200#define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \
201 DEFINE_PER_CPU(_type, _name) = _initvalue
202
203#define EXPORT_EARLY_PER_CPU_SYMBOL(_name) \
204 EXPORT_PER_CPU_SYMBOL(_name)
205
206#define DECLARE_EARLY_PER_CPU(_type, _name) \
207 DECLARE_PER_CPU(_type, _name)
208
209#define early_per_cpu(_name, _cpu) per_cpu(_name, _cpu)
210#define early_per_cpu_ptr(_name) NULL
211/* no early_per_cpu_map() */
212
213#endif /* !CONFIG_SMP */
214
215#endif /* _ASM_X86_PERCPU_H */