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 */
 19struct 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
 34struct 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
 64extern spinlock_t pcpu_lock;
 65
 66extern struct list_head *pcpu_slot;
 67extern int pcpu_nr_slots;
 68extern int pcpu_nr_empty_pop_pages;
 69
 70extern struct pcpu_chunk *pcpu_first_chunk;
 71extern 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 */
 80static 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 */
 92static 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 */
104static 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
113struct 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
124extern struct percpu_stats pcpu_stats;
125extern struct pcpu_alloc_info pcpu_stats_ai;
126
127/*
128 * For debug purposes. We don't care about the flexible array.
129 */
130static 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 */
146static 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 */
170static 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 */
183static 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 */
198static 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
210static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
211{
212}
213
214static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
215{
216}
217
218static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
219{
220}
221
222static inline void pcpu_stats_chunk_alloc(void)
223{
224}
225
226static inline void pcpu_stats_chunk_dealloc(void)
227{
228}
229
230#endif /* !CONFIG_PERCPU_STATS */
231
232#endif