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 	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 
69 extern spinlock_t pcpu_lock;
70 
71 extern struct list_head *pcpu_chunk_lists;
72 extern int pcpu_nr_slots;
73 extern int pcpu_sidelined_slot;
74 extern int pcpu_to_depopulate_slot;
75 extern int pcpu_nr_empty_pop_pages;
76 
77 extern struct pcpu_chunk *pcpu_first_chunk;
78 extern 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  */
pcpu_chunk_nr_blocks(struct pcpu_chunk * chunk)87 static 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  */
pcpu_nr_pages_to_map_bits(int pages)99 static 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  */
pcpu_chunk_map_bits(struct pcpu_chunk * chunk)111 static 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 /**
117  * pcpu_obj_full_size - helper to calculate size of each accounted object
118  * @size: size of area to allocate in bytes
119  *
120  * For each accounted object there is an extra space which is used to store
121  * obj_cgroup membership. Charge it too.
122  */
pcpu_obj_full_size(size_t size)123 static inline size_t pcpu_obj_full_size(size_t size)
124 {
125 	size_t extra_size = 0;
126 
127 #ifdef CONFIG_MEMCG_KMEM
128 	extra_size += size / PCPU_MIN_ALLOC_SIZE * sizeof(struct obj_cgroup *);
129 #endif
130 
131 	return size * num_possible_cpus() + extra_size;
132 }
133 
134 #ifdef CONFIG_PERCPU_STATS
135 
136 #include <linux/spinlock.h>
137 
138 struct percpu_stats {
139 	u64 nr_alloc;		/* lifetime # of allocations */
140 	u64 nr_dealloc;		/* lifetime # of deallocations */
141 	u64 nr_cur_alloc;	/* current # of allocations */
142 	u64 nr_max_alloc;	/* max # of live allocations */
143 	u32 nr_chunks;		/* current # of live chunks */
144 	u32 nr_max_chunks;	/* max # of live chunks */
145 	size_t min_alloc_size;	/* min allocation size */
146 	size_t max_alloc_size;	/* max allocation size */
147 };
148 
149 extern struct percpu_stats pcpu_stats;
150 extern struct pcpu_alloc_info pcpu_stats_ai;
151 
152 /*
153  * For debug purposes. We don't care about the flexible array.
154  */
pcpu_stats_save_ai(const struct pcpu_alloc_info * ai)155 static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
156 {
157 	memcpy(&pcpu_stats_ai, ai, sizeof(struct pcpu_alloc_info));
158 
159 	/* initialize min_alloc_size to unit_size */
160 	pcpu_stats.min_alloc_size = pcpu_stats_ai.unit_size;
161 }
162 
163 /*
164  * pcpu_stats_area_alloc - increment area allocation stats
165  * @chunk: the location of the area being allocated
166  * @size: size of area to allocate in bytes
167  *
168  * CONTEXT:
169  * pcpu_lock.
170  */
pcpu_stats_area_alloc(struct pcpu_chunk * chunk,size_t size)171 static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
172 {
173 	lockdep_assert_held(&pcpu_lock);
174 
175 	pcpu_stats.nr_alloc++;
176 	pcpu_stats.nr_cur_alloc++;
177 	pcpu_stats.nr_max_alloc =
178 		max(pcpu_stats.nr_max_alloc, pcpu_stats.nr_cur_alloc);
179 	pcpu_stats.min_alloc_size =
180 		min(pcpu_stats.min_alloc_size, size);
181 	pcpu_stats.max_alloc_size =
182 		max(pcpu_stats.max_alloc_size, size);
183 
184 	chunk->nr_alloc++;
185 	chunk->max_alloc_size = max(chunk->max_alloc_size, size);
186 }
187 
188 /*
189  * pcpu_stats_area_dealloc - decrement allocation stats
190  * @chunk: the location of the area being deallocated
191  *
192  * CONTEXT:
193  * pcpu_lock.
194  */
pcpu_stats_area_dealloc(struct pcpu_chunk * chunk)195 static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
196 {
197 	lockdep_assert_held(&pcpu_lock);
198 
199 	pcpu_stats.nr_dealloc++;
200 	pcpu_stats.nr_cur_alloc--;
201 
202 	chunk->nr_alloc--;
203 }
204 
205 /*
206  * pcpu_stats_chunk_alloc - increment chunk stats
207  */
pcpu_stats_chunk_alloc(void)208 static inline void pcpu_stats_chunk_alloc(void)
209 {
210 	unsigned long flags;
211 	spin_lock_irqsave(&pcpu_lock, flags);
212 
213 	pcpu_stats.nr_chunks++;
214 	pcpu_stats.nr_max_chunks =
215 		max(pcpu_stats.nr_max_chunks, pcpu_stats.nr_chunks);
216 
217 	spin_unlock_irqrestore(&pcpu_lock, flags);
218 }
219 
220 /*
221  * pcpu_stats_chunk_dealloc - decrement chunk stats
222  */
pcpu_stats_chunk_dealloc(void)223 static inline void pcpu_stats_chunk_dealloc(void)
224 {
225 	unsigned long flags;
226 	spin_lock_irqsave(&pcpu_lock, flags);
227 
228 	pcpu_stats.nr_chunks--;
229 
230 	spin_unlock_irqrestore(&pcpu_lock, flags);
231 }
232 
233 #else
234 
pcpu_stats_save_ai(const struct pcpu_alloc_info * ai)235 static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
236 {
237 }
238 
pcpu_stats_area_alloc(struct pcpu_chunk * chunk,size_t size)239 static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
240 {
241 }
242 
pcpu_stats_area_dealloc(struct pcpu_chunk * chunk)243 static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
244 {
245 }
246 
pcpu_stats_chunk_alloc(void)247 static inline void pcpu_stats_chunk_alloc(void)
248 {
249 }
250 
pcpu_stats_chunk_dealloc(void)251 static inline void pcpu_stats_chunk_dealloc(void)
252 {
253 }
254 
255 #endif /* !CONFIG_PERCPU_STATS */
256 
257 #endif
258