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