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1da177e4 LT |
1 | #ifndef __LINUX_PERCPU_H |
2 | #define __LINUX_PERCPU_H | |
7ff6f082 | 3 | |
0a3021f4 | 4 | #include <linux/preempt.h> |
1da177e4 LT |
5 | #include <linux/slab.h> /* For kmalloc() */ |
6 | #include <linux/smp.h> | |
7ff6f082 | 7 | #include <linux/cpumask.h> |
6a242909 | 8 | #include <linux/pfn.h> |
7ff6f082 | 9 | |
1da177e4 LT |
10 | #include <asm/percpu.h> |
11 | ||
d3770449 | 12 | #ifndef PER_CPU_BASE_SECTION |
5280e004 | 13 | #ifdef CONFIG_SMP |
0bd74fa8 | 14 | #define PER_CPU_BASE_SECTION ".data.percpu" |
d3770449 BG |
15 | #else |
16 | #define PER_CPU_BASE_SECTION ".data" | |
17 | #endif | |
18 | #endif | |
19 | ||
20 | #ifdef CONFIG_SMP | |
5280e004 | 21 | |
44c81433 | 22 | #ifdef MODULE |
0bd74fa8 | 23 | #define PER_CPU_SHARED_ALIGNED_SECTION "" |
44c81433 | 24 | #else |
0bd74fa8 | 25 | #define PER_CPU_SHARED_ALIGNED_SECTION ".shared_aligned" |
44c81433 | 26 | #endif |
0bd74fa8 | 27 | #define PER_CPU_FIRST_SECTION ".first" |
44c81433 | 28 | |
0bd74fa8 BG |
29 | #else |
30 | ||
0bd74fa8 BG |
31 | #define PER_CPU_SHARED_ALIGNED_SECTION "" |
32 | #define PER_CPU_FIRST_SECTION "" | |
33 | ||
34 | #endif | |
63cc8c75 | 35 | |
0bd74fa8 BG |
36 | #define DEFINE_PER_CPU_SECTION(type, name, section) \ |
37 | __attribute__((__section__(PER_CPU_BASE_SECTION section))) \ | |
63cc8c75 | 38 | PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name |
0bd74fa8 | 39 | |
5280e004 | 40 | #define DEFINE_PER_CPU(type, name) \ |
0bd74fa8 | 41 | DEFINE_PER_CPU_SECTION(type, name, "") |
5280e004 | 42 | |
0bd74fa8 BG |
43 | #define DEFINE_PER_CPU_SHARED_ALIGNED(type, name) \ |
44 | DEFINE_PER_CPU_SECTION(type, name, PER_CPU_SHARED_ALIGNED_SECTION) \ | |
45 | ____cacheline_aligned_in_smp | |
63cc8c75 | 46 | |
0bd74fa8 BG |
47 | #define DEFINE_PER_CPU_PAGE_ALIGNED(type, name) \ |
48 | DEFINE_PER_CPU_SECTION(type, name, ".page_aligned") | |
49 | ||
50 | #define DEFINE_PER_CPU_FIRST(type, name) \ | |
51 | DEFINE_PER_CPU_SECTION(type, name, PER_CPU_FIRST_SECTION) | |
5280e004 | 52 | |
53 | #define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var) | |
54 | #define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var) | |
55 | ||
6a242909 | 56 | /* enough to cover all DEFINE_PER_CPUs in modules */ |
b00742d3 | 57 | #ifdef CONFIG_MODULES |
6a242909 | 58 | #define PERCPU_MODULE_RESERVE (8 << 10) |
b00742d3 | 59 | #else |
6a242909 | 60 | #define PERCPU_MODULE_RESERVE 0 |
1da177e4 LT |
61 | #endif |
62 | ||
6a242909 | 63 | #ifndef PERCPU_ENOUGH_ROOM |
b00742d3 | 64 | #define PERCPU_ENOUGH_ROOM \ |
6a242909 TH |
65 | (ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES) + \ |
66 | PERCPU_MODULE_RESERVE) | |
67 | #endif | |
b00742d3 | 68 | |
632bbfee JB |
69 | /* |
70 | * Must be an lvalue. Since @var must be a simple identifier, | |
71 | * we force a syntax error here if it isn't. | |
72 | */ | |
73 | #define get_cpu_var(var) (*({ \ | |
a666ecfb | 74 | extern int simple_identifier_##var(void); \ |
632bbfee JB |
75 | preempt_disable(); \ |
76 | &__get_cpu_var(var); })) | |
1da177e4 LT |
77 | #define put_cpu_var(var) preempt_enable() |
78 | ||
79 | #ifdef CONFIG_SMP | |
80 | ||
fbf59bc9 | 81 | #ifdef CONFIG_HAVE_DYNAMIC_PER_CPU_AREA |
1da177e4 | 82 | |
8d408b4b | 83 | /* minimum unit size, also is the maximum supported allocation size */ |
6a242909 | 84 | #define PCPU_MIN_UNIT_SIZE PFN_ALIGN(64 << 10) |
8d408b4b TH |
85 | |
86 | /* | |
87 | * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy | |
88 | * back on the first chunk if arch is manually allocating and mapping | |
89 | * it for faster access (as a part of large page mapping for example). | |
90 | * Note that dynamic percpu allocator covers both static and dynamic | |
91 | * areas, so these values are bigger than PERCPU_MODULE_RESERVE. | |
92 | * | |
93 | * On typical configuration with modules, the following values leave | |
94 | * about 8k of free space on the first chunk after boot on both x86_32 | |
95 | * and 64 when module support is enabled. When module support is | |
96 | * disabled, it's much tighter. | |
97 | */ | |
98 | #ifndef PERCPU_DYNAMIC_RESERVE | |
99 | # if BITS_PER_LONG > 32 | |
100 | # ifdef CONFIG_MODULES | |
6a242909 | 101 | # define PERCPU_DYNAMIC_RESERVE (24 << 10) |
8d408b4b | 102 | # else |
6a242909 | 103 | # define PERCPU_DYNAMIC_RESERVE (16 << 10) |
8d408b4b TH |
104 | # endif |
105 | # else | |
106 | # ifdef CONFIG_MODULES | |
6a242909 | 107 | # define PERCPU_DYNAMIC_RESERVE (16 << 10) |
8d408b4b | 108 | # else |
6a242909 | 109 | # define PERCPU_DYNAMIC_RESERVE (8 << 10) |
8d408b4b TH |
110 | # endif |
111 | # endif | |
112 | #endif /* PERCPU_DYNAMIC_RESERVE */ | |
113 | ||
fbf59bc9 | 114 | extern void *pcpu_base_addr; |
1da177e4 | 115 | |
8d408b4b | 116 | typedef struct page * (*pcpu_get_page_fn_t)(unsigned int cpu, int pageno); |
fbf59bc9 TH |
117 | typedef void (*pcpu_populate_pte_fn_t)(unsigned long addr); |
118 | ||
8d408b4b | 119 | extern size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn, |
edcb4639 TH |
120 | size_t static_size, size_t reserved_size, |
121 | ssize_t unit_size, ssize_t dyn_size, | |
122 | void *base_addr, | |
123 | pcpu_populate_pte_fn_t populate_pte_fn); | |
8d408b4b | 124 | |
f2a8205c TH |
125 | /* |
126 | * Use this to get to a cpu's version of the per-cpu object | |
127 | * dynamically allocated. Non-atomic access to the current CPU's | |
128 | * version should probably be combined with get_cpu()/put_cpu(). | |
129 | */ | |
fbf59bc9 TH |
130 | #define per_cpu_ptr(ptr, cpu) SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu))) |
131 | ||
edcb4639 TH |
132 | extern void *__alloc_reserved_percpu(size_t size, size_t align); |
133 | ||
fbf59bc9 TH |
134 | #else /* CONFIG_HAVE_DYNAMIC_PER_CPU_AREA */ |
135 | ||
136 | struct percpu_data { | |
137 | void *ptrs[1]; | |
138 | }; | |
139 | ||
140 | #define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata) | |
141 | ||
f2a8205c TH |
142 | #define per_cpu_ptr(ptr, cpu) \ |
143 | ({ \ | |
144 | struct percpu_data *__p = __percpu_disguise(ptr); \ | |
145 | (__typeof__(ptr))__p->ptrs[(cpu)]; \ | |
146 | }) | |
147 | ||
fbf59bc9 TH |
148 | #endif /* CONFIG_HAVE_DYNAMIC_PER_CPU_AREA */ |
149 | ||
f2a8205c TH |
150 | extern void *__alloc_percpu(size_t size, size_t align); |
151 | extern void free_percpu(void *__pdata); | |
1da177e4 LT |
152 | |
153 | #else /* CONFIG_SMP */ | |
154 | ||
b36128c8 | 155 | #define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); }) |
7ff6f082 | 156 | |
f2a8205c | 157 | static inline void *__alloc_percpu(size_t size, size_t align) |
7ff6f082 | 158 | { |
f2a8205c TH |
159 | /* |
160 | * Can't easily make larger alignment work with kmalloc. WARN | |
161 | * on it. Larger alignment should only be used for module | |
162 | * percpu sections on SMP for which this path isn't used. | |
163 | */ | |
e3176036 | 164 | WARN_ON_ONCE(align > SMP_CACHE_BYTES); |
d2b02615 | 165 | return kzalloc(size, GFP_KERNEL); |
7ff6f082 MP |
166 | } |
167 | ||
f2a8205c | 168 | static inline void free_percpu(void *p) |
7ff6f082 | 169 | { |
f2a8205c | 170 | kfree(p); |
1da177e4 LT |
171 | } |
172 | ||
173 | #endif /* CONFIG_SMP */ | |
174 | ||
313e458f RR |
175 | #define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type), \ |
176 | __alignof__(type)) | |
1da177e4 LT |
177 | |
178 | #endif /* __LINUX_PERCPU_H */ |