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 #ifdef CONFIG_PERCPU_STATS
117 
118 #include <linux/spinlock.h>
119 
120 struct 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 
131 extern struct percpu_stats pcpu_stats;
132 extern struct pcpu_alloc_info pcpu_stats_ai;
133 
134 /*
135  * For debug purposes. We don't care about the flexible array.
136  */
pcpu_stats_save_ai(const struct pcpu_alloc_info * ai)137 static 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  */
pcpu_stats_area_alloc(struct pcpu_chunk * chunk,size_t size)153 static 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  */
pcpu_stats_area_dealloc(struct pcpu_chunk * chunk)177 static 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  */
pcpu_stats_chunk_alloc(void)190 static 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  */
pcpu_stats_chunk_dealloc(void)205 static 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 
pcpu_stats_save_ai(const struct pcpu_alloc_info * ai)217 static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
218 {
219 }
220 
pcpu_stats_area_alloc(struct pcpu_chunk * chunk,size_t size)221 static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
222 {
223 }
224 
pcpu_stats_area_dealloc(struct pcpu_chunk * chunk)225 static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
226 {
227 }
228 
pcpu_stats_chunk_alloc(void)229 static inline void pcpu_stats_chunk_alloc(void)
230 {
231 }
232 
pcpu_stats_chunk_dealloc(void)233 static inline void pcpu_stats_chunk_dealloc(void)
234 {
235 }
236 
237 #endif /* !CONFIG_PERCPU_STATS */
238 
239 #endif
240