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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 | ||
6a242909 | 12 | /* enough to cover all DEFINE_PER_CPUs in modules */ |
b00742d3 | 13 | #ifdef CONFIG_MODULES |
6a242909 | 14 | #define PERCPU_MODULE_RESERVE (8 << 10) |
b00742d3 | 15 | #else |
6a242909 | 16 | #define PERCPU_MODULE_RESERVE 0 |
1da177e4 LT |
17 | #endif |
18 | ||
6a242909 | 19 | #ifndef PERCPU_ENOUGH_ROOM |
b00742d3 | 20 | #define PERCPU_ENOUGH_ROOM \ |
6a242909 TH |
21 | (ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES) + \ |
22 | PERCPU_MODULE_RESERVE) | |
23 | #endif | |
b00742d3 | 24 | |
632bbfee JB |
25 | /* |
26 | * Must be an lvalue. Since @var must be a simple identifier, | |
27 | * we force a syntax error here if it isn't. | |
28 | */ | |
29 | #define get_cpu_var(var) (*({ \ | |
a666ecfb | 30 | extern int simple_identifier_##var(void); \ |
632bbfee JB |
31 | preempt_disable(); \ |
32 | &__get_cpu_var(var); })) | |
1da177e4 LT |
33 | #define put_cpu_var(var) preempt_enable() |
34 | ||
35 | #ifdef CONFIG_SMP | |
36 | ||
fbf59bc9 | 37 | #ifdef CONFIG_HAVE_DYNAMIC_PER_CPU_AREA |
1da177e4 | 38 | |
8d408b4b | 39 | /* minimum unit size, also is the maximum supported allocation size */ |
6a242909 | 40 | #define PCPU_MIN_UNIT_SIZE PFN_ALIGN(64 << 10) |
8d408b4b TH |
41 | |
42 | /* | |
43 | * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy | |
6b19b0c2 TH |
44 | * back on the first chunk for dynamic percpu allocation if arch is |
45 | * manually allocating and mapping it for faster access (as a part of | |
46 | * large page mapping for example). | |
8d408b4b | 47 | * |
6b19b0c2 TH |
48 | * The following values give between one and two pages of free space |
49 | * after typical minimal boot (2-way SMP, single disk and NIC) with | |
50 | * both defconfig and a distro config on x86_64 and 32. More | |
51 | * intelligent way to determine this would be nice. | |
8d408b4b | 52 | */ |
6b19b0c2 TH |
53 | #if BITS_PER_LONG > 32 |
54 | #define PERCPU_DYNAMIC_RESERVE (20 << 10) | |
55 | #else | |
56 | #define PERCPU_DYNAMIC_RESERVE (12 << 10) | |
57 | #endif | |
8d408b4b | 58 | |
fbf59bc9 | 59 | extern void *pcpu_base_addr; |
1da177e4 | 60 | |
8d408b4b | 61 | typedef struct page * (*pcpu_get_page_fn_t)(unsigned int cpu, int pageno); |
fbf59bc9 TH |
62 | typedef void (*pcpu_populate_pte_fn_t)(unsigned long addr); |
63 | ||
8d408b4b | 64 | extern size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn, |
edcb4639 | 65 | size_t static_size, size_t reserved_size, |
6074d5b0 | 66 | ssize_t dyn_size, ssize_t unit_size, |
edcb4639 TH |
67 | void *base_addr, |
68 | pcpu_populate_pte_fn_t populate_pte_fn); | |
8d408b4b | 69 | |
66c3a757 TH |
70 | extern ssize_t __init pcpu_embed_first_chunk( |
71 | size_t static_size, size_t reserved_size, | |
72 | ssize_t dyn_size, ssize_t unit_size); | |
73 | ||
f2a8205c TH |
74 | /* |
75 | * Use this to get to a cpu's version of the per-cpu object | |
76 | * dynamically allocated. Non-atomic access to the current CPU's | |
77 | * version should probably be combined with get_cpu()/put_cpu(). | |
78 | */ | |
fbf59bc9 TH |
79 | #define per_cpu_ptr(ptr, cpu) SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu))) |
80 | ||
edcb4639 TH |
81 | extern void *__alloc_reserved_percpu(size_t size, size_t align); |
82 | ||
fbf59bc9 TH |
83 | #else /* CONFIG_HAVE_DYNAMIC_PER_CPU_AREA */ |
84 | ||
85 | struct percpu_data { | |
86 | void *ptrs[1]; | |
87 | }; | |
88 | ||
89 | #define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata) | |
90 | ||
f2a8205c TH |
91 | #define per_cpu_ptr(ptr, cpu) \ |
92 | ({ \ | |
93 | struct percpu_data *__p = __percpu_disguise(ptr); \ | |
94 | (__typeof__(ptr))__p->ptrs[(cpu)]; \ | |
95 | }) | |
96 | ||
fbf59bc9 TH |
97 | #endif /* CONFIG_HAVE_DYNAMIC_PER_CPU_AREA */ |
98 | ||
f2a8205c TH |
99 | extern void *__alloc_percpu(size_t size, size_t align); |
100 | extern void free_percpu(void *__pdata); | |
1da177e4 LT |
101 | |
102 | #else /* CONFIG_SMP */ | |
103 | ||
b36128c8 | 104 | #define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); }) |
7ff6f082 | 105 | |
f2a8205c | 106 | static inline void *__alloc_percpu(size_t size, size_t align) |
7ff6f082 | 107 | { |
f2a8205c TH |
108 | /* |
109 | * Can't easily make larger alignment work with kmalloc. WARN | |
110 | * on it. Larger alignment should only be used for module | |
111 | * percpu sections on SMP for which this path isn't used. | |
112 | */ | |
e3176036 | 113 | WARN_ON_ONCE(align > SMP_CACHE_BYTES); |
d2b02615 | 114 | return kzalloc(size, GFP_KERNEL); |
7ff6f082 MP |
115 | } |
116 | ||
f2a8205c | 117 | static inline void free_percpu(void *p) |
7ff6f082 | 118 | { |
f2a8205c | 119 | kfree(p); |
1da177e4 LT |
120 | } |
121 | ||
122 | #endif /* CONFIG_SMP */ | |
123 | ||
313e458f RR |
124 | #define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type), \ |
125 | __alignof__(type)) | |
1da177e4 | 126 | |
066123a5 TH |
127 | /* |
128 | * Optional methods for optimized non-lvalue per-cpu variable access. | |
129 | * | |
130 | * @var can be a percpu variable or a field of it and its size should | |
131 | * equal char, int or long. percpu_read() evaluates to a lvalue and | |
132 | * all others to void. | |
133 | * | |
134 | * These operations are guaranteed to be atomic w.r.t. preemption. | |
135 | * The generic versions use plain get/put_cpu_var(). Archs are | |
136 | * encouraged to implement single-instruction alternatives which don't | |
137 | * require preemption protection. | |
138 | */ | |
139 | #ifndef percpu_read | |
140 | # define percpu_read(var) \ | |
141 | ({ \ | |
142 | typeof(per_cpu_var(var)) __tmp_var__; \ | |
143 | __tmp_var__ = get_cpu_var(var); \ | |
144 | put_cpu_var(var); \ | |
145 | __tmp_var__; \ | |
146 | }) | |
147 | #endif | |
148 | ||
149 | #define __percpu_generic_to_op(var, val, op) \ | |
150 | do { \ | |
151 | get_cpu_var(var) op val; \ | |
152 | put_cpu_var(var); \ | |
153 | } while (0) | |
154 | ||
155 | #ifndef percpu_write | |
156 | # define percpu_write(var, val) __percpu_generic_to_op(var, (val), =) | |
157 | #endif | |
158 | ||
159 | #ifndef percpu_add | |
160 | # define percpu_add(var, val) __percpu_generic_to_op(var, (val), +=) | |
161 | #endif | |
162 | ||
163 | #ifndef percpu_sub | |
164 | # define percpu_sub(var, val) __percpu_generic_to_op(var, (val), -=) | |
165 | #endif | |
166 | ||
167 | #ifndef percpu_and | |
168 | # define percpu_and(var, val) __percpu_generic_to_op(var, (val), &=) | |
169 | #endif | |
170 | ||
171 | #ifndef percpu_or | |
172 | # define percpu_or(var, val) __percpu_generic_to_op(var, (val), |=) | |
173 | #endif | |
174 | ||
175 | #ifndef percpu_xor | |
176 | # define percpu_xor(var, val) __percpu_generic_to_op(var, (val), ^=) | |
177 | #endif | |
178 | ||
1da177e4 | 179 | #endif /* __LINUX_PERCPU_H */ |