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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __LINUX_PERCPU_H
3#define __LINUX_PERCPU_H
4
5#include <linux/alloc_tag.h>
6#include <linux/cleanup.h>
7#include <linux/compiler_types.h>
8#include <linux/init.h>
9#include <linux/mmdebug.h>
10#include <linux/pfn.h>
11#include <linux/preempt.h>
12#include <linux/sched.h>
13#include <linux/smp.h>
14
15#include <asm/percpu.h>
16
17/* enough to cover all DEFINE_PER_CPUs in modules */
18#ifdef CONFIG_MODULES
19#define PERCPU_MODULE_RESERVE (8 << 10)
20#else
21#define PERCPU_MODULE_RESERVE 0
22#endif
23
24/* minimum unit size, also is the maximum supported allocation size */
25#define PCPU_MIN_UNIT_SIZE PFN_ALIGN(32 << 10)
26
27/* minimum allocation size and shift in bytes */
28#define PCPU_MIN_ALLOC_SHIFT 2
29#define PCPU_MIN_ALLOC_SIZE (1 << PCPU_MIN_ALLOC_SHIFT)
30
31/*
32 * The PCPU_BITMAP_BLOCK_SIZE must be the same size as PAGE_SIZE as the
33 * updating of hints is used to manage the nr_empty_pop_pages in both
34 * the chunk and globally.
35 */
36#define PCPU_BITMAP_BLOCK_SIZE PAGE_SIZE
37#define PCPU_BITMAP_BLOCK_BITS (PCPU_BITMAP_BLOCK_SIZE >> \
38 PCPU_MIN_ALLOC_SHIFT)
39
40#ifdef CONFIG_KMALLOC_PARTITION_CACHES
41# if defined(CONFIG_LOCKDEP) && !defined(CONFIG_PAGE_SIZE_4KB)
42# define PERCPU_DYNAMIC_SIZE_SHIFT 13
43# else
44# define PERCPU_DYNAMIC_SIZE_SHIFT 12
45#endif /* LOCKDEP and PAGE_SIZE > 4KiB */
46#else
47#define PERCPU_DYNAMIC_SIZE_SHIFT 10
48#endif
49
50/*
51 * Percpu allocator can serve percpu allocations before slab is
52 * initialized which allows slab to depend on the percpu allocator.
53 * The following parameter decide how much resource to preallocate
54 * for this. Keep PERCPU_DYNAMIC_RESERVE equal to or larger than
55 * PERCPU_DYNAMIC_EARLY_SIZE.
56 */
57#define PERCPU_DYNAMIC_EARLY_SIZE (20 << PERCPU_DYNAMIC_SIZE_SHIFT)
58
59/*
60 * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy
61 * back on the first chunk for dynamic percpu allocation if arch is
62 * manually allocating and mapping it for faster access (as a part of
63 * large page mapping for example).
64 *
65 * The following values give between one and two pages of free space
66 * after typical minimal boot (2-way SMP, single disk and NIC) with
67 * both defconfig and a distro config on x86_64 and 32. More
68 * intelligent way to determine this would be nice.
69 */
70#if BITS_PER_LONG > 32
71#define PERCPU_DYNAMIC_RESERVE (28 << PERCPU_DYNAMIC_SIZE_SHIFT)
72#else
73#define PERCPU_DYNAMIC_RESERVE (20 << PERCPU_DYNAMIC_SIZE_SHIFT)
74#endif
75
76extern void *pcpu_base_addr;
77extern const unsigned long *pcpu_unit_offsets;
78
79struct pcpu_group_info {
80 int nr_units; /* aligned # of units */
81 unsigned long base_offset; /* base address offset */
82 unsigned int *cpu_map; /* unit->cpu map, empty
83 * entries contain NR_CPUS */
84};
85
86struct pcpu_alloc_info {
87 size_t static_size;
88 size_t reserved_size;
89 size_t dyn_size;
90 size_t unit_size;
91 size_t atom_size;
92 size_t alloc_size;
93 size_t __ai_size; /* internal, don't use */
94 int nr_groups; /* 0 if grouping unnecessary */
95 struct pcpu_group_info groups[];
96};
97
98enum pcpu_fc {
99 PCPU_FC_AUTO,
100 PCPU_FC_EMBED,
101 PCPU_FC_PAGE,
102
103 PCPU_FC_NR,
104};
105extern const char * const pcpu_fc_names[PCPU_FC_NR];
106
107extern enum pcpu_fc pcpu_chosen_fc;
108
109typedef int (pcpu_fc_cpu_to_node_fn_t)(int cpu);
110typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
111
112extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
113 int nr_units);
114extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
115
116extern void __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
117 void *base_addr);
118
119extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
120 size_t atom_size,
121 pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
122 pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn);
123
124#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
125void __init pcpu_populate_pte(unsigned long addr);
126extern int __init pcpu_page_first_chunk(size_t reserved_size,
127 pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn);
128#endif
129
130extern bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr);
131extern bool is_kernel_percpu_address(unsigned long addr);
132
133#if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
134extern void __init setup_per_cpu_areas(void);
135#endif
136
137extern void __percpu *pcpu_alloc_noprof(size_t size, size_t align, bool reserved,
138 gfp_t gfp) __alloc_size(1);
139
140#define __alloc_percpu_gfp(_size, _align, _gfp) \
141 alloc_hooks(pcpu_alloc_noprof(_size, _align, false, _gfp))
142#define __alloc_percpu(_size, _align) \
143 alloc_hooks(pcpu_alloc_noprof(_size, _align, false, GFP_KERNEL))
144#define __alloc_reserved_percpu(_size, _align) \
145 alloc_hooks(pcpu_alloc_noprof(_size, _align, true, GFP_KERNEL))
146
147#define alloc_percpu_gfp(type, gfp) \
148 (typeof(type) __percpu *)__alloc_percpu_gfp(sizeof(type), \
149 __alignof__(type), gfp)
150#define alloc_percpu(type) \
151 (typeof(type) __percpu *)__alloc_percpu(sizeof(type), \
152 __alignof__(type))
153#define alloc_percpu_noprof(type) \
154 ((typeof(type) __percpu *)pcpu_alloc_noprof(sizeof(type), \
155 __alignof__(type), false, GFP_KERNEL))
156
157extern void free_percpu(void __percpu *__pdata);
158
159DEFINE_FREE(free_percpu, void __percpu *, free_percpu(_T))
160
161extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
162
163extern unsigned long pcpu_nr_pages(void);
164
165#endif /* __LINUX_PERCPU_H */