WAR: gr3d: limit 3d clock when camera is on
[linux-2.6.git] / include / linux / percpu-defs.h
1 #ifndef _LINUX_PERCPU_DEFS_H
2 #define _LINUX_PERCPU_DEFS_H
3
4 /*
5  * Base implementations of per-CPU variable declarations and definitions, where
6  * the section in which the variable is to be placed is provided by the
7  * 'sec' argument.  This may be used to affect the parameters governing the
8  * variable's storage.
9  *
10  * NOTE!  The sections for the DECLARE and for the DEFINE must match, lest
11  * linkage errors occur due the compiler generating the wrong code to access
12  * that section.
13  */
14 #define __PCPU_ATTRS(sec)                                               \
15         __percpu __attribute__((section(PER_CPU_BASE_SECTION sec)))     \
16         PER_CPU_ATTRIBUTES
17
18 #define __PCPU_DUMMY_ATTRS                                              \
19         __attribute__((section(".discard"), unused))
20
21 /*
22  * Macro which verifies @ptr is a percpu pointer without evaluating
23  * @ptr.  This is to be used in percpu accessors to verify that the
24  * input parameter is a percpu pointer.
25  */
26 #define __verify_pcpu_ptr(ptr)  do {                                    \
27         const void __percpu *__vpp_verify = (typeof(ptr))NULL;          \
28         (void)__vpp_verify;                                             \
29 } while (0)
30
31 /*
32  * s390 and alpha modules require percpu variables to be defined as
33  * weak to force the compiler to generate GOT based external
34  * references for them.  This is necessary because percpu sections
35  * will be located outside of the usually addressable area.
36  *
37  * This definition puts the following two extra restrictions when
38  * defining percpu variables.
39  *
40  * 1. The symbol must be globally unique, even the static ones.
41  * 2. Static percpu variables cannot be defined inside a function.
42  *
43  * Archs which need weak percpu definitions should define
44  * ARCH_NEEDS_WEAK_PER_CPU in asm/percpu.h when necessary.
45  *
46  * To ensure that the generic code observes the above two
47  * restrictions, if CONFIG_DEBUG_FORCE_WEAK_PER_CPU is set weak
48  * definition is used for all cases.
49  */
50 #if defined(ARCH_NEEDS_WEAK_PER_CPU) || defined(CONFIG_DEBUG_FORCE_WEAK_PER_CPU)
51 /*
52  * __pcpu_scope_* dummy variable is used to enforce scope.  It
53  * receives the static modifier when it's used in front of
54  * DEFINE_PER_CPU() and will trigger build failure if
55  * DECLARE_PER_CPU() is used for the same variable.
56  *
57  * __pcpu_unique_* dummy variable is used to enforce symbol uniqueness
58  * such that hidden weak symbol collision, which will cause unrelated
59  * variables to share the same address, can be detected during build.
60  */
61 #define DECLARE_PER_CPU_SECTION(type, name, sec)                        \
62         extern __PCPU_DUMMY_ATTRS char __pcpu_scope_##name;             \
63         extern __PCPU_ATTRS(sec) __typeof__(type) name
64
65 #define DEFINE_PER_CPU_SECTION(type, name, sec)                         \
66         __PCPU_DUMMY_ATTRS char __pcpu_scope_##name;                    \
67         extern __PCPU_DUMMY_ATTRS char __pcpu_unique_##name;            \
68         __PCPU_DUMMY_ATTRS char __pcpu_unique_##name;                   \
69         __PCPU_ATTRS(sec) PER_CPU_DEF_ATTRIBUTES __weak                 \
70         __typeof__(type) name
71 #else
72 /*
73  * Normal declaration and definition macros.
74  */
75 #define DECLARE_PER_CPU_SECTION(type, name, sec)                        \
76         extern __PCPU_ATTRS(sec) __typeof__(type) name
77
78 #define DEFINE_PER_CPU_SECTION(type, name, sec)                         \
79         __PCPU_ATTRS(sec) PER_CPU_DEF_ATTRIBUTES                        \
80         __typeof__(type) name
81 #endif
82
83 /*
84  * Variant on the per-CPU variable declaration/definition theme used for
85  * ordinary per-CPU variables.
86  */
87 #define DECLARE_PER_CPU(type, name)                                     \
88         DECLARE_PER_CPU_SECTION(type, name, "")
89
90 #define DEFINE_PER_CPU(type, name)                                      \
91         DEFINE_PER_CPU_SECTION(type, name, "")
92
93 /*
94  * Declaration/definition used for per-CPU variables that must come first in
95  * the set of variables.
96  */
97 #define DECLARE_PER_CPU_FIRST(type, name)                               \
98         DECLARE_PER_CPU_SECTION(type, name, PER_CPU_FIRST_SECTION)
99
100 #define DEFINE_PER_CPU_FIRST(type, name)                                \
101         DEFINE_PER_CPU_SECTION(type, name, PER_CPU_FIRST_SECTION)
102
103 /*
104  * Declaration/definition used for per-CPU variables that must be cacheline
105  * aligned under SMP conditions so that, whilst a particular instance of the
106  * data corresponds to a particular CPU, inefficiencies due to direct access by
107  * other CPUs are reduced by preventing the data from unnecessarily spanning
108  * cachelines.
109  *
110  * An example of this would be statistical data, where each CPU's set of data
111  * is updated by that CPU alone, but the data from across all CPUs is collated
112  * by a CPU processing a read from a proc file.
113  */
114 #define DECLARE_PER_CPU_SHARED_ALIGNED(type, name)                      \
115         DECLARE_PER_CPU_SECTION(type, name, PER_CPU_SHARED_ALIGNED_SECTION) \
116         ____cacheline_aligned_in_smp
117
118 #define DEFINE_PER_CPU_SHARED_ALIGNED(type, name)                       \
119         DEFINE_PER_CPU_SECTION(type, name, PER_CPU_SHARED_ALIGNED_SECTION) \
120         ____cacheline_aligned_in_smp
121
122 #define DECLARE_PER_CPU_ALIGNED(type, name)                             \
123         DECLARE_PER_CPU_SECTION(type, name, PER_CPU_ALIGNED_SECTION)    \
124         ____cacheline_aligned
125
126 #define DEFINE_PER_CPU_ALIGNED(type, name)                              \
127         DEFINE_PER_CPU_SECTION(type, name, PER_CPU_ALIGNED_SECTION)     \
128         ____cacheline_aligned
129
130 /*
131  * Declaration/definition used for per-CPU variables that must be page aligned.
132  */
133 #define DECLARE_PER_CPU_PAGE_ALIGNED(type, name)                        \
134         DECLARE_PER_CPU_SECTION(type, name, "..page_aligned")           \
135         __aligned(PAGE_SIZE)
136
137 #define DEFINE_PER_CPU_PAGE_ALIGNED(type, name)                         \
138         DEFINE_PER_CPU_SECTION(type, name, "..page_aligned")            \
139         __aligned(PAGE_SIZE)
140
141 /*
142  * Declaration/definition used for per-CPU variables that must be read mostly.
143  */
144 #define DECLARE_PER_CPU_READ_MOSTLY(type, name)                 \
145         DECLARE_PER_CPU_SECTION(type, name, "..readmostly")
146
147 #define DEFINE_PER_CPU_READ_MOSTLY(type, name)                          \
148         DEFINE_PER_CPU_SECTION(type, name, "..readmostly")
149
150 /*
151  * Intermodule exports for per-CPU variables.  sparse forgets about
152  * address space across EXPORT_SYMBOL(), change EXPORT_SYMBOL() to
153  * noop if __CHECKER__.
154  */
155 #ifndef __CHECKER__
156 #define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(var)
157 #define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(var)
158 #else
159 #define EXPORT_PER_CPU_SYMBOL(var)
160 #define EXPORT_PER_CPU_SYMBOL_GPL(var)
161 #endif
162
163 #endif /* _LINUX_PERCPU_DEFS_H */