Linux kernel mirror (for testing)
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1#ifndef __LINUX_PERCPU_H
2#define __LINUX_PERCPU_H
3
4#include <linux/mmdebug.h>
5#include <linux/preempt.h>
6#include <linux/smp.h>
7#include <linux/cpumask.h>
8#include <linux/pfn.h>
9#include <linux/init.h>
10
11#include <asm/percpu.h>
12
13/* enough to cover all DEFINE_PER_CPUs in modules */
14#ifdef CONFIG_MODULES
15#define PERCPU_MODULE_RESERVE (8 << 10)
16#else
17#define PERCPU_MODULE_RESERVE 0
18#endif
19
20#ifndef PERCPU_ENOUGH_ROOM
21#define PERCPU_ENOUGH_ROOM \
22 (ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES) + \
23 PERCPU_MODULE_RESERVE)
24#endif
25
26/* minimum unit size, also is the maximum supported allocation size */
27#define PCPU_MIN_UNIT_SIZE PFN_ALIGN(32 << 10)
28
29/*
30 * Percpu allocator can serve percpu allocations before slab is
31 * initialized which allows slab to depend on the percpu allocator.
32 * The following two parameters decide how much resource to
33 * preallocate for this. Keep PERCPU_DYNAMIC_RESERVE equal to or
34 * larger than PERCPU_DYNAMIC_EARLY_SIZE.
35 */
36#define PERCPU_DYNAMIC_EARLY_SLOTS 128
37#define PERCPU_DYNAMIC_EARLY_SIZE (12 << 10)
38
39/*
40 * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy
41 * back on the first chunk for dynamic percpu allocation if arch is
42 * manually allocating and mapping it for faster access (as a part of
43 * large page mapping for example).
44 *
45 * The following values give between one and two pages of free space
46 * after typical minimal boot (2-way SMP, single disk and NIC) with
47 * both defconfig and a distro config on x86_64 and 32. More
48 * intelligent way to determine this would be nice.
49 */
50#if BITS_PER_LONG > 32
51#define PERCPU_DYNAMIC_RESERVE (20 << 10)
52#else
53#define PERCPU_DYNAMIC_RESERVE (12 << 10)
54#endif
55
56extern void *pcpu_base_addr;
57extern const unsigned long *pcpu_unit_offsets;
58
59struct pcpu_group_info {
60 int nr_units; /* aligned # of units */
61 unsigned long base_offset; /* base address offset */
62 unsigned int *cpu_map; /* unit->cpu map, empty
63 * entries contain NR_CPUS */
64};
65
66struct pcpu_alloc_info {
67 size_t static_size;
68 size_t reserved_size;
69 size_t dyn_size;
70 size_t unit_size;
71 size_t atom_size;
72 size_t alloc_size;
73 size_t __ai_size; /* internal, don't use */
74 int nr_groups; /* 0 if grouping unnecessary */
75 struct pcpu_group_info groups[];
76};
77
78enum pcpu_fc {
79 PCPU_FC_AUTO,
80 PCPU_FC_EMBED,
81 PCPU_FC_PAGE,
82
83 PCPU_FC_NR,
84};
85extern const char * const pcpu_fc_names[PCPU_FC_NR];
86
87extern enum pcpu_fc pcpu_chosen_fc;
88
89typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
90 size_t align);
91typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
92typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
93typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
94
95extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
96 int nr_units);
97extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
98
99extern int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
100 void *base_addr);
101
102#ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
103extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
104 size_t atom_size,
105 pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
106 pcpu_fc_alloc_fn_t alloc_fn,
107 pcpu_fc_free_fn_t free_fn);
108#endif
109
110#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
111extern int __init pcpu_page_first_chunk(size_t reserved_size,
112 pcpu_fc_alloc_fn_t alloc_fn,
113 pcpu_fc_free_fn_t free_fn,
114 pcpu_fc_populate_pte_fn_t populate_pte_fn);
115#endif
116
117extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
118extern bool is_kernel_percpu_address(unsigned long addr);
119
120#if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
121extern void __init setup_per_cpu_areas(void);
122#endif
123extern void __init percpu_init_late(void);
124
125extern void __percpu *__alloc_percpu(size_t size, size_t align);
126extern void free_percpu(void __percpu *__pdata);
127extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
128
129#define alloc_percpu(type) \
130 (typeof(type) __percpu *)__alloc_percpu(sizeof(type), __alignof__(type))
131
132#endif /* __LINUX_PERCPU_H */