0dec00f27eb45db5a853cfa621a2513d1b860953
[sfrench/cifs-2.6.git] / include / asm-x86 / percpu.h
1 #ifndef _ASM_X86_PERCPU_H_
2 #define _ASM_X86_PERCPU_H_
3
4 #ifdef CONFIG_X86_64
5 #include <linux/compiler.h>
6
7 /* Same as asm-generic/percpu.h, except that we store the per cpu offset
8    in the PDA. Longer term the PDA and every per cpu variable
9    should be just put into a single section and referenced directly
10    from %gs */
11
12 #ifdef CONFIG_SMP
13 #include <asm/pda.h>
14
15 #define __per_cpu_offset(cpu) (cpu_pda(cpu)->data_offset)
16 #define __my_cpu_offset read_pda(data_offset)
17
18 #define per_cpu_offset(x) (__per_cpu_offset(x))
19
20 #endif
21 #include <asm-generic/percpu.h>
22
23 DECLARE_PER_CPU(struct x8664_pda, pda);
24
25 #else /* CONFIG_X86_64 */
26
27 #ifdef __ASSEMBLY__
28
29 /*
30  * PER_CPU finds an address of a per-cpu variable.
31  *
32  * Args:
33  *    var - variable name
34  *    reg - 32bit register
35  *
36  * The resulting address is stored in the "reg" argument.
37  *
38  * Example:
39  *    PER_CPU(cpu_gdt_descr, %ebx)
40  */
41 #ifdef CONFIG_SMP
42 #define PER_CPU(var, reg)                               \
43         movl %fs:per_cpu__##this_cpu_off, reg;          \
44         lea per_cpu__##var(reg), reg
45 #define PER_CPU_VAR(var)        %fs:per_cpu__##var
46 #else /* ! SMP */
47 #define PER_CPU(var, reg)                       \
48         movl $per_cpu__##var, reg
49 #define PER_CPU_VAR(var)        per_cpu__##var
50 #endif  /* SMP */
51
52 #else /* ...!ASSEMBLY */
53
54 /*
55  * PER_CPU finds an address of a per-cpu variable.
56  *
57  * Args:
58  *    var - variable name
59  *    cpu - 32bit register containing the current CPU number
60  *
61  * The resulting address is stored in the "cpu" argument.
62  *
63  * Example:
64  *    PER_CPU(cpu_gdt_descr, %ebx)
65  */
66 #ifdef CONFIG_SMP
67
68 #define __my_cpu_offset x86_read_percpu(this_cpu_off)
69
70 /* fs segment starts at (positive) offset == __per_cpu_offset[cpu] */
71 #define __percpu_seg "%%fs:"
72
73 #else  /* !SMP */
74
75 #define __percpu_seg ""
76
77 #endif  /* SMP */
78
79 #include <asm-generic/percpu.h>
80
81 /* We can use this directly for local CPU (faster). */
82 DECLARE_PER_CPU(unsigned long, this_cpu_off);
83
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);
87
88 #define percpu_to_op(op,var,val)                                \
89         do {                                                    \
90                 typedef typeof(var) T__;                        \
91                 if (0) { T__ tmp__; tmp__ = (val); }            \
92                 switch (sizeof(var)) {                          \
93                 case 1:                                         \
94                         asm(op "b %1,"__percpu_seg"%0"          \
95                             : "+m" (var)                        \
96                             :"ri" ((T__)val));                  \
97                         break;                                  \
98                 case 2:                                         \
99                         asm(op "w %1,"__percpu_seg"%0"          \
100                             : "+m" (var)                        \
101                             :"ri" ((T__)val));                  \
102                         break;                                  \
103                 case 4:                                         \
104                         asm(op "l %1,"__percpu_seg"%0"          \
105                             : "+m" (var)                        \
106                             :"ri" ((T__)val));                  \
107                         break;                                  \
108                 default: __bad_percpu_size();                   \
109                 }                                               \
110         } while (0)
111
112 #define percpu_from_op(op,var)                                  \
113         ({                                                      \
114                 typeof(var) ret__;                              \
115                 switch (sizeof(var)) {                          \
116                 case 1:                                         \
117                         asm(op "b "__percpu_seg"%1,%0"          \
118                             : "=r" (ret__)                      \
119                             : "m" (var));                       \
120                         break;                                  \
121                 case 2:                                         \
122                         asm(op "w "__percpu_seg"%1,%0"          \
123                             : "=r" (ret__)                      \
124                             : "m" (var));                       \
125                         break;                                  \
126                 case 4:                                         \
127                         asm(op "l "__percpu_seg"%1,%0"          \
128                             : "=r" (ret__)                      \
129                             : "m" (var));                       \
130                         break;                                  \
131                 default: __bad_percpu_size();                   \
132                 }                                               \
133                 ret__; })
134
135 #define x86_read_percpu(var) percpu_from_op("mov", per_cpu__##var)
136 #define x86_write_percpu(var,val) percpu_to_op("mov", per_cpu__##var, val)
137 #define x86_add_percpu(var,val) percpu_to_op("add", per_cpu__##var, val)
138 #define x86_sub_percpu(var,val) percpu_to_op("sub", per_cpu__##var, val)
139 #define x86_or_percpu(var,val) percpu_to_op("or", per_cpu__##var, val)
140 #endif /* !__ASSEMBLY__ */
141 #endif /* !CONFIG_X86_64 */
142 #endif /* _ASM_X86_PERCPU_H_ */