xref: /openbmc/linux/mm/percpu-internal.h (revision feac8c8b)
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 struct 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 
24 struct 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 
57 extern spinlock_t pcpu_lock;
58 
59 extern struct list_head *pcpu_slot;
60 extern int pcpu_nr_slots;
61 extern int pcpu_nr_empty_pop_pages;
62 
63 extern struct pcpu_chunk *pcpu_first_chunk;
64 extern 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  */
73 static 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  */
85 static 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  */
97 static 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 
106 struct 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 
117 extern struct percpu_stats pcpu_stats;
118 extern struct pcpu_alloc_info pcpu_stats_ai;
119 
120 /*
121  * For debug purposes. We don't care about the flexible array.
122  */
123 static 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  */
139 static 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  */
163 static 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  */
176 static 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  */
191 static 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 
203 static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
204 {
205 }
206 
207 static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
208 {
209 }
210 
211 static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
212 {
213 }
214 
215 static inline void pcpu_stats_chunk_alloc(void)
216 {
217 }
218 
219 static inline void pcpu_stats_chunk_dealloc(void)
220 {
221 }
222 
223 #endif /* !CONFIG_PERCPU_STATS */
224 
225 #endif
226