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 */
19 struct 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
34 struct 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 int start_offset; /* the overlap with the previous
52 region to have a page aligned
53 base_addr */
54 int end_offset; /* additional area required to
55 have the region end page
56 aligned */
57
58 int nr_pages; /* # of pages served by this chunk */
59 int nr_populated; /* # of populated pages */
60 int nr_empty_pop_pages; /* # of empty populated pages */
61 unsigned long populated[]; /* populated bitmap */
62 };
63
64 extern spinlock_t pcpu_lock;
65
66 extern struct list_head *pcpu_slot;
67 extern int pcpu_nr_slots;
68 extern int pcpu_nr_empty_pop_pages;
69
70 extern struct pcpu_chunk *pcpu_first_chunk;
71 extern struct pcpu_chunk *pcpu_reserved_chunk;
72
73 /**
74 * pcpu_chunk_nr_blocks - converts nr_pages to # of md_blocks
75 * @chunk: chunk of interest
76 *
77 * This conversion is from the number of physical pages that the chunk
78 * serves to the number of bitmap blocks used.
79 */
80 static inline int pcpu_chunk_nr_blocks(struct pcpu_chunk *chunk)
81 {
82 return chunk->nr_pages * PAGE_SIZE / PCPU_BITMAP_BLOCK_SIZE;
83 }
84
85 /**
86 * pcpu_nr_pages_to_map_bits - converts the pages to size of bitmap
87 * @pages: number of physical pages
88 *
89 * This conversion is from physical pages to the number of bits
90 * required in the bitmap.
91 */
92 static inline int pcpu_nr_pages_to_map_bits(int pages)
93 {
94 return pages * PAGE_SIZE / PCPU_MIN_ALLOC_SIZE;
95 }
96
97 /**
98 * pcpu_chunk_map_bits - helper to convert nr_pages to size of bitmap
99 * @chunk: chunk of interest
100 *
101 * This conversion is from the number of physical pages that the chunk
102 * serves to the number of bits in the bitmap.
103 */
104 static inline int pcpu_chunk_map_bits(struct pcpu_chunk *chunk)
105 {
106 return pcpu_nr_pages_to_map_bits(chunk->nr_pages);
107 }
108
109 #ifdef CONFIG_PERCPU_STATS
110
111 #include <linux/spinlock.h>
112
113 struct percpu_stats {
114 u64 nr_alloc; /* lifetime # of allocations */
115 u64 nr_dealloc; /* lifetime # of deallocations */
116 u64 nr_cur_alloc; /* current # of allocations */
117 u64 nr_max_alloc; /* max # of live allocations */
118 u32 nr_chunks; /* current # of live chunks */
119 u32 nr_max_chunks; /* max # of live chunks */
120 size_t min_alloc_size; /* min allocaiton size */
121 size_t max_alloc_size; /* max allocation size */
122 };
123
124 extern struct percpu_stats pcpu_stats;
125 extern struct pcpu_alloc_info pcpu_stats_ai;
126
127 /*
128 * For debug purposes. We don't care about the flexible array.
129 */
130 static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
131 {
132 memcpy(&pcpu_stats_ai, ai, sizeof(struct pcpu_alloc_info));
133
134 /* initialize min_alloc_size to unit_size */
135 pcpu_stats.min_alloc_size = pcpu_stats_ai.unit_size;
136 }
137
138 /*
139 * pcpu_stats_area_alloc - increment area allocation stats
140 * @chunk: the location of the area being allocated
141 * @size: size of area to allocate in bytes
142 *
143 * CONTEXT:
144 * pcpu_lock.
145 */
146 static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
147 {
148 lockdep_assert_held(&pcpu_lock);
149
150 pcpu_stats.nr_alloc++;
151 pcpu_stats.nr_cur_alloc++;
152 pcpu_stats.nr_max_alloc =
153 max(pcpu_stats.nr_max_alloc, pcpu_stats.nr_cur_alloc);
154 pcpu_stats.min_alloc_size =
155 min(pcpu_stats.min_alloc_size, size);
156 pcpu_stats.max_alloc_size =
157 max(pcpu_stats.max_alloc_size, size);
158
159 chunk->nr_alloc++;
160 chunk->max_alloc_size = max(chunk->max_alloc_size, size);
161 }
162
163 /*
164 * pcpu_stats_area_dealloc - decrement allocation stats
165 * @chunk: the location of the area being deallocated
166 *
167 * CONTEXT:
168 * pcpu_lock.
169 */
170 static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
171 {
172 lockdep_assert_held(&pcpu_lock);
173
174 pcpu_stats.nr_dealloc++;
175 pcpu_stats.nr_cur_alloc--;
176
177 chunk->nr_alloc--;
178 }
179
180 /*
181 * pcpu_stats_chunk_alloc - increment chunk stats
182 */
183 static inline void pcpu_stats_chunk_alloc(void)
184 {
185 unsigned long flags;
186 spin_lock_irqsave(&pcpu_lock, flags);
187
188 pcpu_stats.nr_chunks++;
189 pcpu_stats.nr_max_chunks =
190 max(pcpu_stats.nr_max_chunks, pcpu_stats.nr_chunks);
191
192 spin_unlock_irqrestore(&pcpu_lock, flags);
193 }
194
195 /*
196 * pcpu_stats_chunk_dealloc - decrement chunk stats
197 */
198 static inline void pcpu_stats_chunk_dealloc(void)
199 {
200 unsigned long flags;
201 spin_lock_irqsave(&pcpu_lock, flags);
202
203 pcpu_stats.nr_chunks--;
204
205 spin_unlock_irqrestore(&pcpu_lock, flags);
206 }
207
208 #else
209
210 static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
211 {
212 }
213
214 static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
215 {
216 }
217
218 static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
219 {
220 }
221
222 static inline void pcpu_stats_chunk_alloc(void)
223 {
224 }
225
226 static inline void pcpu_stats_chunk_dealloc(void)
227 {
228 }
229
230 #endif /* !CONFIG_PERCPU_STATS */
231
232 #endif