1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef __LINUX_PERCPU_H |
3 | #define __LINUX_PERCPU_H |
4 | |
5 | #include <linux/mmdebug.h> |
6 | #include <linux/preempt.h> |
7 | #include <linux/smp.h> |
8 | #include <linux/cpumask.h> |
9 | #include <linux/pfn.h> |
10 | #include <linux/init.h> |
11 | #include <linux/cleanup.h> |
12 | |
13 | #include <asm/percpu.h> |
14 | |
15 | /* enough to cover all DEFINE_PER_CPUs in modules */ |
16 | #ifdef CONFIG_MODULES |
17 | #define PERCPU_MODULE_RESERVE (8 << 10) |
18 | #else |
19 | #define PERCPU_MODULE_RESERVE 0 |
20 | #endif |
21 | |
22 | /* minimum unit size, also is the maximum supported allocation size */ |
23 | #define PCPU_MIN_UNIT_SIZE PFN_ALIGN(32 << 10) |
24 | |
25 | /* minimum allocation size and shift in bytes */ |
26 | #define PCPU_MIN_ALLOC_SHIFT 2 |
27 | #define PCPU_MIN_ALLOC_SIZE (1 << PCPU_MIN_ALLOC_SHIFT) |
28 | |
29 | /* |
30 | * The PCPU_BITMAP_BLOCK_SIZE must be the same size as PAGE_SIZE as the |
31 | * updating of hints is used to manage the nr_empty_pop_pages in both |
32 | * the chunk and globally. |
33 | */ |
34 | #define PCPU_BITMAP_BLOCK_SIZE PAGE_SIZE |
35 | #define PCPU_BITMAP_BLOCK_BITS (PCPU_BITMAP_BLOCK_SIZE >> \ |
36 | PCPU_MIN_ALLOC_SHIFT) |
37 | |
38 | #ifdef CONFIG_RANDOM_KMALLOC_CACHES |
39 | #define PERCPU_DYNAMIC_SIZE_SHIFT 12 |
40 | #else |
41 | #define PERCPU_DYNAMIC_SIZE_SHIFT 10 |
42 | #endif |
43 | |
44 | /* |
45 | * Percpu allocator can serve percpu allocations before slab is |
46 | * initialized which allows slab to depend on the percpu allocator. |
47 | * The following parameter decide how much resource to preallocate |
48 | * for this. Keep PERCPU_DYNAMIC_RESERVE equal to or larger than |
49 | * PERCPU_DYNAMIC_EARLY_SIZE. |
50 | */ |
51 | #define PERCPU_DYNAMIC_EARLY_SIZE (20 << PERCPU_DYNAMIC_SIZE_SHIFT) |
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 << PERCPU_DYNAMIC_SIZE_SHIFT) |
66 | #else |
67 | #define PERCPU_DYNAMIC_RESERVE (20 << PERCPU_DYNAMIC_SIZE_SHIFT) |
68 | #endif |
69 | |
70 | extern void *pcpu_base_addr; |
71 | extern const unsigned long *pcpu_unit_offsets; |
72 | |
73 | struct 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 | |
80 | struct 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 | |
92 | enum pcpu_fc { |
93 | PCPU_FC_AUTO, |
94 | PCPU_FC_EMBED, |
95 | PCPU_FC_PAGE, |
96 | |
97 | PCPU_FC_NR, |
98 | }; |
99 | extern const char * const pcpu_fc_names[PCPU_FC_NR]; |
100 | |
101 | extern enum pcpu_fc pcpu_chosen_fc; |
102 | |
103 | typedef int (pcpu_fc_cpu_to_node_fn_t)(int cpu); |
104 | typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to); |
105 | |
106 | extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, |
107 | int nr_units); |
108 | extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai); |
109 | |
110 | extern void __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, |
111 | void *base_addr); |
112 | |
113 | extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, |
114 | size_t atom_size, |
115 | pcpu_fc_cpu_distance_fn_t cpu_distance_fn, |
116 | pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn); |
117 | |
118 | #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK |
119 | void __init pcpu_populate_pte(unsigned long addr); |
120 | extern int __init pcpu_page_first_chunk(size_t reserved_size, |
121 | pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn); |
122 | #endif |
123 | |
124 | extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align) __alloc_size(1); |
125 | extern bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr); |
126 | extern bool is_kernel_percpu_address(unsigned long addr); |
127 | |
128 | #if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) |
129 | extern void __init setup_per_cpu_areas(void); |
130 | #endif |
131 | |
132 | extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp) __alloc_size(1); |
133 | extern void __percpu *__alloc_percpu(size_t size, size_t align) __alloc_size(1); |
134 | extern void free_percpu(void __percpu *__pdata); |
135 | extern size_t pcpu_alloc_size(void __percpu *__pdata); |
136 | |
137 | DEFINE_FREE(free_percpu, void __percpu *, free_percpu(_T)) |
138 | |
139 | extern phys_addr_t per_cpu_ptr_to_phys(void *addr); |
140 | |
141 | #define alloc_percpu_gfp(type, gfp) \ |
142 | (typeof(type) __percpu *)__alloc_percpu_gfp(sizeof(type), \ |
143 | __alignof__(type), gfp) |
144 | #define alloc_percpu(type) \ |
145 | (typeof(type) __percpu *)__alloc_percpu(sizeof(type), \ |
146 | __alignof__(type)) |
147 | |
148 | extern unsigned long pcpu_nr_pages(void); |
149 | |
150 | #endif /* __LINUX_PERCPU_H */ |
151 | |