xref: /openbmc/linux/mm/percpu-internal.h (revision 612a462a)
1 #ifndef _MM_PERCPU_INTERNAL_H
2 #define _MM_PERCPU_INTERNAL_H
3 
4 #include <linux/types.h>
5 #include <linux/percpu.h>
6 
7 /*
8  * pcpu_block_md is the metadata block struct.
9  * Each chunk's bitmap is split into a number of full blocks.
10  * All units are in terms of bits.
11  */
12 struct pcpu_block_md {
13 	int                     contig_hint;    /* contig hint for block */
14 	int                     contig_hint_start; /* block relative starting
15 						      position of the contig hint */
16 	int                     left_free;      /* size of free space along
17 						   the left side of the block */
18 	int                     right_free;     /* size of free space along
19 						   the right side of the block */
20 	int                     first_free;     /* block position of first free */
21 };
22 
23 struct pcpu_chunk {
24 #ifdef CONFIG_PERCPU_STATS
25 	int			nr_alloc;	/* # of allocations */
26 	size_t			max_alloc_size; /* largest allocation size */
27 #endif
28 
29 	struct list_head	list;		/* linked to pcpu_slot lists */
30 	int			free_bytes;	/* free bytes in the chunk */
31 	int			contig_bits;	/* max contiguous size hint */
32 	int			contig_bits_start; /* contig_bits starting
33 						      offset */
34 	void			*base_addr;	/* base address of this chunk */
35 
36 	unsigned long		*alloc_map;	/* allocation map */
37 	unsigned long		*bound_map;	/* boundary map */
38 	struct pcpu_block_md	*md_blocks;	/* metadata blocks */
39 
40 	void			*data;		/* chunk data */
41 	int			first_bit;	/* no free below this */
42 	bool			immutable;	/* no [de]population allowed */
43 	int			start_offset;	/* the overlap with the previous
44 						   region to have a page aligned
45 						   base_addr */
46 	int			end_offset;	/* additional area required to
47 						   have the region end page
48 						   aligned */
49 
50 	int			nr_pages;	/* # of pages served by this chunk */
51 	int			nr_populated;	/* # of populated pages */
52 	int                     nr_empty_pop_pages; /* # of empty populated pages */
53 	unsigned long		populated[];	/* populated bitmap */
54 };
55 
56 extern spinlock_t pcpu_lock;
57 
58 extern struct list_head *pcpu_slot;
59 extern int pcpu_nr_slots;
60 extern int pcpu_nr_empty_pop_pages;
61 
62 extern struct pcpu_chunk *pcpu_first_chunk;
63 extern struct pcpu_chunk *pcpu_reserved_chunk;
64 
65 /**
66  * pcpu_chunk_nr_blocks - converts nr_pages to # of md_blocks
67  * @chunk: chunk of interest
68  *
69  * This conversion is from the number of physical pages that the chunk
70  * serves to the number of bitmap blocks used.
71  */
72 static inline int pcpu_chunk_nr_blocks(struct pcpu_chunk *chunk)
73 {
74 	return chunk->nr_pages * PAGE_SIZE / PCPU_BITMAP_BLOCK_SIZE;
75 }
76 
77 /**
78  * pcpu_nr_pages_to_map_bits - converts the pages to size of bitmap
79  * @pages: number of physical pages
80  *
81  * This conversion is from physical pages to the number of bits
82  * required in the bitmap.
83  */
84 static inline int pcpu_nr_pages_to_map_bits(int pages)
85 {
86 	return pages * PAGE_SIZE / PCPU_MIN_ALLOC_SIZE;
87 }
88 
89 /**
90  * pcpu_chunk_map_bits - helper to convert nr_pages to size of bitmap
91  * @chunk: chunk of interest
92  *
93  * This conversion is from the number of physical pages that the chunk
94  * serves to the number of bits in the bitmap.
95  */
96 static inline int pcpu_chunk_map_bits(struct pcpu_chunk *chunk)
97 {
98 	return pcpu_nr_pages_to_map_bits(chunk->nr_pages);
99 }
100 
101 #ifdef CONFIG_PERCPU_STATS
102 
103 #include <linux/spinlock.h>
104 
105 struct percpu_stats {
106 	u64 nr_alloc;		/* lifetime # of allocations */
107 	u64 nr_dealloc;		/* lifetime # of deallocations */
108 	u64 nr_cur_alloc;	/* current # of allocations */
109 	u64 nr_max_alloc;	/* max # of live allocations */
110 	u32 nr_chunks;		/* current # of live chunks */
111 	u32 nr_max_chunks;	/* max # of live chunks */
112 	size_t min_alloc_size;	/* min allocaiton size */
113 	size_t max_alloc_size;	/* max allocation size */
114 };
115 
116 extern struct percpu_stats pcpu_stats;
117 extern struct pcpu_alloc_info pcpu_stats_ai;
118 
119 /*
120  * For debug purposes. We don't care about the flexible array.
121  */
122 static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
123 {
124 	memcpy(&pcpu_stats_ai, ai, sizeof(struct pcpu_alloc_info));
125 
126 	/* initialize min_alloc_size to unit_size */
127 	pcpu_stats.min_alloc_size = pcpu_stats_ai.unit_size;
128 }
129 
130 /*
131  * pcpu_stats_area_alloc - increment area allocation stats
132  * @chunk: the location of the area being allocated
133  * @size: size of area to allocate in bytes
134  *
135  * CONTEXT:
136  * pcpu_lock.
137  */
138 static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
139 {
140 	lockdep_assert_held(&pcpu_lock);
141 
142 	pcpu_stats.nr_alloc++;
143 	pcpu_stats.nr_cur_alloc++;
144 	pcpu_stats.nr_max_alloc =
145 		max(pcpu_stats.nr_max_alloc, pcpu_stats.nr_cur_alloc);
146 	pcpu_stats.min_alloc_size =
147 		min(pcpu_stats.min_alloc_size, size);
148 	pcpu_stats.max_alloc_size =
149 		max(pcpu_stats.max_alloc_size, size);
150 
151 	chunk->nr_alloc++;
152 	chunk->max_alloc_size = max(chunk->max_alloc_size, size);
153 }
154 
155 /*
156  * pcpu_stats_area_dealloc - decrement allocation stats
157  * @chunk: the location of the area being deallocated
158  *
159  * CONTEXT:
160  * pcpu_lock.
161  */
162 static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
163 {
164 	lockdep_assert_held(&pcpu_lock);
165 
166 	pcpu_stats.nr_dealloc++;
167 	pcpu_stats.nr_cur_alloc--;
168 
169 	chunk->nr_alloc--;
170 }
171 
172 /*
173  * pcpu_stats_chunk_alloc - increment chunk stats
174  */
175 static inline void pcpu_stats_chunk_alloc(void)
176 {
177 	unsigned long flags;
178 	spin_lock_irqsave(&pcpu_lock, flags);
179 
180 	pcpu_stats.nr_chunks++;
181 	pcpu_stats.nr_max_chunks =
182 		max(pcpu_stats.nr_max_chunks, pcpu_stats.nr_chunks);
183 
184 	spin_unlock_irqrestore(&pcpu_lock, flags);
185 }
186 
187 /*
188  * pcpu_stats_chunk_dealloc - decrement chunk stats
189  */
190 static inline void pcpu_stats_chunk_dealloc(void)
191 {
192 	unsigned long flags;
193 	spin_lock_irqsave(&pcpu_lock, flags);
194 
195 	pcpu_stats.nr_chunks--;
196 
197 	spin_unlock_irqrestore(&pcpu_lock, flags);
198 }
199 
200 #else
201 
202 static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
203 {
204 }
205 
206 static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
207 {
208 }
209 
210 static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
211 {
212 }
213 
214 static inline void pcpu_stats_chunk_alloc(void)
215 {
216 }
217 
218 static inline void pcpu_stats_chunk_dealloc(void)
219 {
220 }
221 
222 #endif /* !CONFIG_PERCPU_STATS */
223 
224 #endif
225