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Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _MM_PERCPU_INTERNAL_H
3#define _MM_PERCPU_INTERNAL_H
4
5#include <linux/types.h>
6#include <linux/percpu.h>
7
8/*
9 * pcpu_block_md is the metadata block struct.
10 * Each chunk's bitmap is split into a number of full blocks.
11 * All units are in terms of bits.
12 *
13 * The scan hint is the largest known contiguous area before the contig hint.
14 * It is not necessarily the actual largest contig hint though. There is an
15 * invariant that the scan_hint_start > contig_hint_start iff
16 * scan_hint == contig_hint. This is necessary because when scanning forward,
17 * we don't know if a new contig hint would be better than the current one.
18 */
19struct pcpu_block_md {
20 int scan_hint; /* scan hint for block */
21 int scan_hint_start; /* block relative starting
22 position of the scan hint */
23 int contig_hint; /* contig hint for block */
24 int contig_hint_start; /* block relative starting
25 position of the contig hint */
26 int left_free; /* size of free space along
27 the left side of the block */
28 int right_free; /* size of free space along
29 the right side of the block */
30 int first_free; /* block position of first free */
31 int nr_bits; /* total bits responsible for */
32};
33
34struct pcpu_chunk {
35#ifdef CONFIG_PERCPU_STATS
36 int nr_alloc; /* # of allocations */
37 size_t max_alloc_size; /* largest allocation size */
38#endif
39
40 struct list_head list; /* linked to pcpu_slot lists */
41 int free_bytes; /* free bytes in the chunk */
42 struct pcpu_block_md chunk_md;
43 void *base_addr; /* base address of this chunk */
44
45 unsigned long *alloc_map; /* allocation map */
46 unsigned long *bound_map; /* boundary map */
47 struct pcpu_block_md *md_blocks; /* metadata blocks */
48
49 void *data; /* chunk data */
50 bool immutable; /* no [de]population allowed */
51 bool isolated; /* isolated from active chunk
52 slots */
53 int start_offset; /* the overlap with the previous
54 region to have a page aligned
55 base_addr */
56 int end_offset; /* additional area required to
57 have the region end page
58 aligned */
59#ifdef CONFIG_MEMCG_KMEM
60 struct obj_cgroup **obj_cgroups; /* vector of object cgroups */
61#endif
62
63 int nr_pages; /* # of pages served by this chunk */
64 int nr_populated; /* # of populated pages */
65 int nr_empty_pop_pages; /* # of empty populated pages */
66 unsigned long populated[]; /* populated bitmap */
67};
68
69extern spinlock_t pcpu_lock;
70
71extern struct list_head *pcpu_chunk_lists;
72extern int pcpu_nr_slots;
73extern int pcpu_sidelined_slot;
74extern int pcpu_to_depopulate_slot;
75extern int pcpu_nr_empty_pop_pages;
76
77extern struct pcpu_chunk *pcpu_first_chunk;
78extern struct pcpu_chunk *pcpu_reserved_chunk;
79
80/**
81 * pcpu_chunk_nr_blocks - converts nr_pages to # of md_blocks
82 * @chunk: chunk of interest
83 *
84 * This conversion is from the number of physical pages that the chunk
85 * serves to the number of bitmap blocks used.
86 */
87static inline int pcpu_chunk_nr_blocks(struct pcpu_chunk *chunk)
88{
89 return chunk->nr_pages * PAGE_SIZE / PCPU_BITMAP_BLOCK_SIZE;
90}
91
92/**
93 * pcpu_nr_pages_to_map_bits - converts the pages to size of bitmap
94 * @pages: number of physical pages
95 *
96 * This conversion is from physical pages to the number of bits
97 * required in the bitmap.
98 */
99static inline int pcpu_nr_pages_to_map_bits(int pages)
100{
101 return pages * PAGE_SIZE / PCPU_MIN_ALLOC_SIZE;
102}
103
104/**
105 * pcpu_chunk_map_bits - helper to convert nr_pages to size of bitmap
106 * @chunk: chunk of interest
107 *
108 * This conversion is from the number of physical pages that the chunk
109 * serves to the number of bits in the bitmap.
110 */
111static inline int pcpu_chunk_map_bits(struct pcpu_chunk *chunk)
112{
113 return pcpu_nr_pages_to_map_bits(chunk->nr_pages);
114}
115
116#ifdef CONFIG_PERCPU_STATS
117
118#include <linux/spinlock.h>
119
120struct percpu_stats {
121 u64 nr_alloc; /* lifetime # of allocations */
122 u64 nr_dealloc; /* lifetime # of deallocations */
123 u64 nr_cur_alloc; /* current # of allocations */
124 u64 nr_max_alloc; /* max # of live allocations */
125 u32 nr_chunks; /* current # of live chunks */
126 u32 nr_max_chunks; /* max # of live chunks */
127 size_t min_alloc_size; /* min allocation size */
128 size_t max_alloc_size; /* max allocation size */
129};
130
131extern struct percpu_stats pcpu_stats;
132extern struct pcpu_alloc_info pcpu_stats_ai;
133
134/*
135 * For debug purposes. We don't care about the flexible array.
136 */
137static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
138{
139 memcpy(&pcpu_stats_ai, ai, sizeof(struct pcpu_alloc_info));
140
141 /* initialize min_alloc_size to unit_size */
142 pcpu_stats.min_alloc_size = pcpu_stats_ai.unit_size;
143}
144
145/*
146 * pcpu_stats_area_alloc - increment area allocation stats
147 * @chunk: the location of the area being allocated
148 * @size: size of area to allocate in bytes
149 *
150 * CONTEXT:
151 * pcpu_lock.
152 */
153static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
154{
155 lockdep_assert_held(&pcpu_lock);
156
157 pcpu_stats.nr_alloc++;
158 pcpu_stats.nr_cur_alloc++;
159 pcpu_stats.nr_max_alloc =
160 max(pcpu_stats.nr_max_alloc, pcpu_stats.nr_cur_alloc);
161 pcpu_stats.min_alloc_size =
162 min(pcpu_stats.min_alloc_size, size);
163 pcpu_stats.max_alloc_size =
164 max(pcpu_stats.max_alloc_size, size);
165
166 chunk->nr_alloc++;
167 chunk->max_alloc_size = max(chunk->max_alloc_size, size);
168}
169
170/*
171 * pcpu_stats_area_dealloc - decrement allocation stats
172 * @chunk: the location of the area being deallocated
173 *
174 * CONTEXT:
175 * pcpu_lock.
176 */
177static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
178{
179 lockdep_assert_held(&pcpu_lock);
180
181 pcpu_stats.nr_dealloc++;
182 pcpu_stats.nr_cur_alloc--;
183
184 chunk->nr_alloc--;
185}
186
187/*
188 * pcpu_stats_chunk_alloc - increment chunk stats
189 */
190static inline void pcpu_stats_chunk_alloc(void)
191{
192 unsigned long flags;
193 spin_lock_irqsave(&pcpu_lock, flags);
194
195 pcpu_stats.nr_chunks++;
196 pcpu_stats.nr_max_chunks =
197 max(pcpu_stats.nr_max_chunks, pcpu_stats.nr_chunks);
198
199 spin_unlock_irqrestore(&pcpu_lock, flags);
200}
201
202/*
203 * pcpu_stats_chunk_dealloc - decrement chunk stats
204 */
205static inline void pcpu_stats_chunk_dealloc(void)
206{
207 unsigned long flags;
208 spin_lock_irqsave(&pcpu_lock, flags);
209
210 pcpu_stats.nr_chunks--;
211
212 spin_unlock_irqrestore(&pcpu_lock, flags);
213}
214
215#else
216
217static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
218{
219}
220
221static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
222{
223}
224
225static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
226{
227}
228
229static inline void pcpu_stats_chunk_alloc(void)
230{
231}
232
233static inline void pcpu_stats_chunk_dealloc(void)
234{
235}
236
237#endif /* !CONFIG_PERCPU_STATS */
238
239#endif