x86, um: ... and asm-x86 move
[linux-2.6.git] / arch / x86 / include / asm / 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 /*
26  * These are supposed to be implemented as a single instruction which
27  * operates on the per-cpu data base segment.  x86-64 doesn't have
28  * that yet, so this is a fairly inefficient workaround for the
29  * meantime.  The single instruction is atomic with respect to
30  * preemption and interrupts, so we need to explicitly disable
31  * interrupts here to achieve the same effect.  However, because it
32  * can be used from within interrupt-disable/enable, we can't actually
33  * disable interrupts; disabling preemption is enough.
34  */
35 #define x86_read_percpu(var)                                            \
36         ({                                                              \
37                 typeof(per_cpu_var(var)) __tmp;                         \
38                 preempt_disable();                                      \
39                 __tmp = __get_cpu_var(var);                             \
40                 preempt_enable();                                       \
41                 __tmp;                                                  \
42         })
43
44 #define x86_write_percpu(var, val)                                      \
45         do {                                                            \
46                 preempt_disable();                                      \
47                 __get_cpu_var(var) = (val);                             \
48                 preempt_enable();                                       \
49         } while(0)
50
51 #else /* CONFIG_X86_64 */
52
53 #ifdef __ASSEMBLY__
54
55 /*
56  * PER_CPU finds an address of a per-cpu variable.
57  *
58  * Args:
59  *    var - variable name
60  *    reg - 32bit register
61  *
62  * The resulting address is stored in the "reg" argument.
63  *
64  * Example:
65  *    PER_CPU(cpu_gdt_descr, %ebx)
66  */
67 #ifdef CONFIG_SMP
68 #define PER_CPU(var, reg)                               \
69         movl %fs:per_cpu__##this_cpu_off, reg;          \
70         lea per_cpu__##var(reg), reg
71 #define PER_CPU_VAR(var)        %fs:per_cpu__##var
72 #else /* ! SMP */
73 #define PER_CPU(var, reg)                       \
74         movl $per_cpu__##var, reg
75 #define PER_CPU_VAR(var)        per_cpu__##var
76 #endif  /* SMP */
77
78 #else /* ...!ASSEMBLY */
79
80 /*
81  * PER_CPU finds an address of a per-cpu variable.
82  *
83  * Args:
84  *    var - variable name
85  *    cpu - 32bit register containing the current CPU number
86  *
87  * The resulting address is stored in the "cpu" argument.
88  *
89  * Example:
90  *    PER_CPU(cpu_gdt_descr, %ebx)
91  */
92 #ifdef CONFIG_SMP
93
94 #define __my_cpu_offset x86_read_percpu(this_cpu_off)
95
96 /* fs segment starts at (positive) offset == __per_cpu_offset[cpu] */
97 #define __percpu_seg "%%fs:"
98
99 #else  /* !SMP */
100
101 #define __percpu_seg ""
102
103 #endif  /* SMP */
104
105 #include <asm-generic/percpu.h>
106
107 /* We can use this directly for local CPU (faster). */
108 DECLARE_PER_CPU(unsigned long, this_cpu_off);
109
110 /* For arch-specific code, we can use direct single-insn ops (they
111  * don't give an lvalue though). */
112 extern void __bad_percpu_size(void);
113
114 #define percpu_to_op(op, var, val)                      \
115 do {                                                    \
116         typedef typeof(var) T__;                        \
117         if (0) {                                        \
118                 T__ tmp__;                              \
119                 tmp__ = (val);                          \
120         }                                               \
121         switch (sizeof(var)) {                          \
122         case 1:                                         \
123                 asm(op "b %1,"__percpu_seg"%0"          \
124                     : "+m" (var)                        \
125                     : "ri" ((T__)val));                 \
126                 break;                                  \
127         case 2:                                         \
128                 asm(op "w %1,"__percpu_seg"%0"          \
129                     : "+m" (var)                        \
130                     : "ri" ((T__)val));                 \
131                 break;                                  \
132         case 4:                                         \
133                 asm(op "l %1,"__percpu_seg"%0"          \
134                     : "+m" (var)                        \
135                     : "ri" ((T__)val));                 \
136                 break;                                  \
137         default: __bad_percpu_size();                   \
138         }                                               \
139 } while (0)
140
141 #define percpu_from_op(op, var)                         \
142 ({                                                      \
143         typeof(var) ret__;                              \
144         switch (sizeof(var)) {                          \
145         case 1:                                         \
146                 asm(op "b "__percpu_seg"%1,%0"          \
147                     : "=r" (ret__)                      \
148                     : "m" (var));                       \
149                 break;                                  \
150         case 2:                                         \
151                 asm(op "w "__percpu_seg"%1,%0"          \
152                     : "=r" (ret__)                      \
153                     : "m" (var));                       \
154                 break;                                  \
155         case 4:                                         \
156                 asm(op "l "__percpu_seg"%1,%0"          \
157                     : "=r" (ret__)                      \
158                     : "m" (var));                       \
159                 break;                                  \
160         default: __bad_percpu_size();                   \
161         }                                               \
162         ret__;                                          \
163 })
164
165 #define x86_read_percpu(var) percpu_from_op("mov", per_cpu__##var)
166 #define x86_write_percpu(var, val) percpu_to_op("mov", per_cpu__##var, val)
167 #define x86_add_percpu(var, val) percpu_to_op("add", per_cpu__##var, val)
168 #define x86_sub_percpu(var, val) percpu_to_op("sub", per_cpu__##var, val)
169 #define x86_or_percpu(var, val) percpu_to_op("or", per_cpu__##var, val)
170 #endif /* !__ASSEMBLY__ */
171 #endif /* !CONFIG_X86_64 */
172
173 #ifdef CONFIG_SMP
174
175 /*
176  * Define the "EARLY_PER_CPU" macros.  These are used for some per_cpu
177  * variables that are initialized and accessed before there are per_cpu
178  * areas allocated.
179  */
180
181 #define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)                  \
182         DEFINE_PER_CPU(_type, _name) = _initvalue;                      \
183         __typeof__(_type) _name##_early_map[NR_CPUS] __initdata =       \
184                                 { [0 ... NR_CPUS-1] = _initvalue };     \
185         __typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
186
187 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name)                      \
188         EXPORT_PER_CPU_SYMBOL(_name)
189
190 #define DECLARE_EARLY_PER_CPU(_type, _name)                     \
191         DECLARE_PER_CPU(_type, _name);                          \
192         extern __typeof__(_type) *_name##_early_ptr;            \
193         extern __typeof__(_type)  _name##_early_map[]
194
195 #define early_per_cpu_ptr(_name) (_name##_early_ptr)
196 #define early_per_cpu_map(_name, _idx) (_name##_early_map[_idx])
197 #define early_per_cpu(_name, _cpu)                              \
198         (early_per_cpu_ptr(_name) ?                             \
199                 early_per_cpu_ptr(_name)[_cpu] :                \
200                 per_cpu(_name, _cpu))
201
202 #else   /* !CONFIG_SMP */
203 #define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)          \
204         DEFINE_PER_CPU(_type, _name) = _initvalue
205
206 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name)                      \
207         EXPORT_PER_CPU_SYMBOL(_name)
208
209 #define DECLARE_EARLY_PER_CPU(_type, _name)                     \
210         DECLARE_PER_CPU(_type, _name)
211
212 #define early_per_cpu(_name, _cpu) per_cpu(_name, _cpu)
213 #define early_per_cpu_ptr(_name) NULL
214 /* no early_per_cpu_map() */
215
216 #endif  /* !CONFIG_SMP */
217
218 #endif /* ASM_X86__PERCPU_H */