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/printk.h>
9#include <linux/pfn.h>
10#include <linux/init.h>
11
12#include <asm/percpu.h>
13
14/* enough to cover all DEFINE_PER_CPUs in modules */
15#ifdef CONFIG_MODULES
16#define PERCPU_MODULE_RESERVE (8 << 10)
17#else
18#define PERCPU_MODULE_RESERVE 0
19#endif
20
21/* minimum unit size, also is the maximum supported allocation size */
22#define PCPU_MIN_UNIT_SIZE PFN_ALIGN(32 << 10)
23
24/* minimum allocation size and shift in bytes */
25#define PCPU_MIN_ALLOC_SHIFT 2
26#define PCPU_MIN_ALLOC_SIZE (1 << PCPU_MIN_ALLOC_SHIFT)
27
28/* number of bits per page, used to trigger a scan if blocks are > PAGE_SIZE */
29#define PCPU_BITS_PER_PAGE (PAGE_SIZE >> PCPU_MIN_ALLOC_SHIFT)
30
31/*
32 * This determines the size of each metadata block. There are several subtle
33 * constraints around this constant. The reserved region must be a multiple of
34 * PCPU_BITMAP_BLOCK_SIZE. Additionally, PCPU_BITMAP_BLOCK_SIZE must be a
35 * multiple of PAGE_SIZE or PAGE_SIZE must be a multiple of
36 * PCPU_BITMAP_BLOCK_SIZE to align with the populated page map. The unit_size
37 * also has to be a multiple of PCPU_BITMAP_BLOCK_SIZE to ensure full blocks.
38 */
39#define PCPU_BITMAP_BLOCK_SIZE PAGE_SIZE
40#define PCPU_BITMAP_BLOCK_BITS (PCPU_BITMAP_BLOCK_SIZE >> \
41 PCPU_MIN_ALLOC_SHIFT)
42
43/*
44 * Percpu allocator can serve percpu allocations before slab is
45 * initialized which allows slab to depend on the percpu allocator.
46 * The following two parameters decide how much resource to
47 * preallocate for this. Keep PERCPU_DYNAMIC_RESERVE equal to or
48 * larger than PERCPU_DYNAMIC_EARLY_SIZE.
49 */
50#define PERCPU_DYNAMIC_EARLY_SLOTS 128
51#define PERCPU_DYNAMIC_EARLY_SIZE (12 << 10)
52
53/*
54 * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy
55 * back on the first chunk for dynamic percpu allocation if arch is
56 * manually allocating and mapping it for faster access (as a part of
57 * large page mapping for example).
58 *
59 * The following values give between one and two pages of free space
60 * after typical minimal boot (2-way SMP, single disk and NIC) with
61 * both defconfig and a distro config on x86_64 and 32. More
62 * intelligent way to determine this would be nice.
63 */
64#if BITS_PER_LONG > 32
65#define PERCPU_DYNAMIC_RESERVE (28 << 10)
66#else
67#define PERCPU_DYNAMIC_RESERVE (20 << 10)
68#endif
69
70extern void *pcpu_base_addr;
71extern const unsigned long *pcpu_unit_offsets;
72
73struct pcpu_group_info {
74 int nr_units; /* aligned # of units */
75 unsigned long base_offset; /* base address offset */
76 unsigned int *cpu_map; /* unit->cpu map, empty
77 * entries contain NR_CPUS */
78};
79
80struct pcpu_alloc_info {
81 size_t static_size;
82 size_t reserved_size;
83 size_t dyn_size;
84 size_t unit_size;
85 size_t atom_size;
86 size_t alloc_size;
87 size_t __ai_size; /* internal, don't use */
88 int nr_groups; /* 0 if grouping unnecessary */
89 struct pcpu_group_info groups[];
90};
91
92enum pcpu_fc {
93 PCPU_FC_AUTO,
94 PCPU_FC_EMBED,
95 PCPU_FC_PAGE,
96
97 PCPU_FC_NR,
98};
99extern const char * const pcpu_fc_names[PCPU_FC_NR];
100
101extern enum pcpu_fc pcpu_chosen_fc;
102
103typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
104 size_t align);
105typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
106typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
107typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
108
109extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
110 int nr_units);
111extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
112
113extern int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
114 void *base_addr);
115
116#ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
117extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
118 size_t atom_size,
119 pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
120 pcpu_fc_alloc_fn_t alloc_fn,
121 pcpu_fc_free_fn_t free_fn);
122#endif
123
124#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
125extern int __init pcpu_page_first_chunk(size_t reserved_size,
126 pcpu_fc_alloc_fn_t alloc_fn,
127 pcpu_fc_free_fn_t free_fn,
128 pcpu_fc_populate_pte_fn_t populate_pte_fn);
129#endif
130
131extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
132extern bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr);
133extern bool is_kernel_percpu_address(unsigned long addr);
134
135#if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
136extern void __init setup_per_cpu_areas(void);
137#endif
138
139extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp);
140extern void __percpu *__alloc_percpu(size_t size, size_t align);
141extern void free_percpu(void __percpu *__pdata);
142extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
143
144#define alloc_percpu_gfp(type, gfp) \
145 (typeof(type) __percpu *)__alloc_percpu_gfp(sizeof(type), \
146 __alignof__(type), gfp)
147#define alloc_percpu(type) \
148 (typeof(type) __percpu *)__alloc_percpu(sizeof(type), \
149 __alignof__(type))
150
151#endif /* __LINUX_PERCPU_H */