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-rw-r--r--include/asm-i386/percpu.h136
1 files changed, 127 insertions, 9 deletions
diff --git a/include/asm-i386/percpu.h b/include/asm-i386/percpu.h
index 510ae1d3486c..f54830b5d5ac 100644
--- a/include/asm-i386/percpu.h
+++ b/include/asm-i386/percpu.h
@@ -1,9 +1,32 @@
1#ifndef __ARCH_I386_PERCPU__ 1#ifndef __ARCH_I386_PERCPU__
2#define __ARCH_I386_PERCPU__ 2#define __ARCH_I386_PERCPU__
3 3
4#ifndef __ASSEMBLY__ 4#ifdef __ASSEMBLY__
5#include <asm-generic/percpu.h> 5
6#else 6/*
7 * PER_CPU finds an address of a per-cpu variable.
8 *
9 * Args:
10 * var - variable name
11 * reg - 32bit register
12 *
13 * The resulting address is stored in the "reg" argument.
14 *
15 * Example:
16 * PER_CPU(cpu_gdt_descr, %ebx)
17 */
18#ifdef CONFIG_SMP
19#define PER_CPU(var, reg) \
20 movl %fs:per_cpu__##this_cpu_off, reg; \
21 lea per_cpu__##var(reg), reg
22#define PER_CPU_VAR(var) %fs:per_cpu__##var
23#else /* ! SMP */
24#define PER_CPU(var, reg) \
25 movl $per_cpu__##var, reg
26#define PER_CPU_VAR(var) per_cpu__##var
27#endif /* SMP */
28
29#else /* ...!ASSEMBLY */
7 30
8/* 31/*
9 * PER_CPU finds an address of a per-cpu variable. 32 * PER_CPU finds an address of a per-cpu variable.
@@ -18,14 +41,109 @@
18 * PER_CPU(cpu_gdt_descr, %ebx) 41 * PER_CPU(cpu_gdt_descr, %ebx)
19 */ 42 */
20#ifdef CONFIG_SMP 43#ifdef CONFIG_SMP
21#define PER_CPU(var, cpu) \ 44/* Same as generic implementation except for optimized local access. */
22 movl __per_cpu_offset(,cpu,4), cpu; \ 45#define __GENERIC_PER_CPU
23 addl $per_cpu__/**/var, cpu; 46
24#else /* ! SMP */ 47/* This is used for other cpus to find our section. */
25#define PER_CPU(var, cpu) \ 48extern unsigned long __per_cpu_offset[];
26 movl $per_cpu__/**/var, cpu; 49
50#define per_cpu_offset(x) (__per_cpu_offset[x])
51
52/* Separate out the type, so (int[3], foo) works. */
53#define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu__##name
54#define DEFINE_PER_CPU(type, name) \
55 __attribute__((__section__(".data.percpu"))) __typeof__(type) per_cpu__##name
56
57/* We can use this directly for local CPU (faster). */
58DECLARE_PER_CPU(unsigned long, this_cpu_off);
59
60/* var is in discarded region: offset to particular copy we want */
61#define per_cpu(var, cpu) (*({ \
62 extern int simple_indentifier_##var(void); \
63 RELOC_HIDE(&per_cpu__##var, __per_cpu_offset[cpu]); }))
64
65#define __raw_get_cpu_var(var) (*({ \
66 extern int simple_indentifier_##var(void); \
67 RELOC_HIDE(&per_cpu__##var, x86_read_percpu(this_cpu_off)); \
68}))
69
70#define __get_cpu_var(var) __raw_get_cpu_var(var)
71
72/* A macro to avoid #include hell... */
73#define percpu_modcopy(pcpudst, src, size) \
74do { \
75 unsigned int __i; \
76 for_each_possible_cpu(__i) \
77 memcpy((pcpudst)+__per_cpu_offset[__i], \
78 (src), (size)); \
79} while (0)
80
81#define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var)
82#define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var)
83
84/* fs segment starts at (positive) offset == __per_cpu_offset[cpu] */
85#define __percpu_seg "%%fs:"
86#else /* !SMP */
87#include <asm-generic/percpu.h>
88#define __percpu_seg ""
27#endif /* SMP */ 89#endif /* SMP */
28 90
91/* For arch-specific code, we can use direct single-insn ops (they
92 * don't give an lvalue though). */
93extern void __bad_percpu_size(void);
94
95#define percpu_to_op(op,var,val) \
96 do { \
97 typedef typeof(var) T__; \
98 if (0) { T__ tmp__; tmp__ = (val); } \
99 switch (sizeof(var)) { \
100 case 1: \
101 asm(op "b %1,"__percpu_seg"%0" \
102 : "+m" (var) \
103 :"ri" ((T__)val)); \
104 break; \
105 case 2: \
106 asm(op "w %1,"__percpu_seg"%0" \
107 : "+m" (var) \
108 :"ri" ((T__)val)); \
109 break; \
110 case 4: \
111 asm(op "l %1,"__percpu_seg"%0" \
112 : "+m" (var) \
113 :"ri" ((T__)val)); \
114 break; \
115 default: __bad_percpu_size(); \
116 } \
117 } while (0)
118
119#define percpu_from_op(op,var) \
120 ({ \
121 typeof(var) ret__; \
122 switch (sizeof(var)) { \
123 case 1: \
124 asm(op "b "__percpu_seg"%1,%0" \
125 : "=r" (ret__) \
126 : "m" (var)); \
127 break; \
128 case 2: \
129 asm(op "w "__percpu_seg"%1,%0" \
130 : "=r" (ret__) \
131 : "m" (var)); \
132 break; \
133 case 4: \
134 asm(op "l "__percpu_seg"%1,%0" \
135 : "=r" (ret__) \
136 : "m" (var)); \
137 break; \
138 default: __bad_percpu_size(); \
139 } \
140 ret__; })
141
142#define x86_read_percpu(var) percpu_from_op("mov", per_cpu__##var)
143#define x86_write_percpu(var,val) percpu_to_op("mov", per_cpu__##var, val)
144#define x86_add_percpu(var,val) percpu_to_op("add", per_cpu__##var, val)
145#define x86_sub_percpu(var,val) percpu_to_op("sub", per_cpu__##var, val)
146#define x86_or_percpu(var,val) percpu_to_op("or", per_cpu__##var, val)
29#endif /* !__ASSEMBLY__ */ 147#endif /* !__ASSEMBLY__ */
30 148
31#endif /* __ARCH_I386_PERCPU__ */ 149#endif /* __ARCH_I386_PERCPU__ */